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Muradyan N, Arakelov V, Sargsyan A, Paronyan A, Arakelov G, Nazaryan K. Impact of mutations on the stability of SARS-CoV-2 nucleocapsid protein structure. Sci Rep 2024; 14:5870. [PMID: 38467657 PMCID: PMC10928099 DOI: 10.1038/s41598-024-55157-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 02/21/2024] [Indexed: 03/13/2024] Open
Abstract
The nucleocapsid (N) protein of SARS-CoV-2 is known to participate in various host cellular processes, including interferon inhibition, RNA interference, apoptosis, and regulation of virus life cycles. Additionally, it has potential as a diagnostic antigen and/or immunogen. Our research focuses on examining structural changes caused by mutations in the N protein. We have modeled the complete tertiary structure of native and mutated forms of the N protein using Alphafold2. Notably, the N protein contains 3 disordered regions. The focus was on investigating the impact of mutations on the stability of the protein's dimeric structure based on binding free energy calculations (MM-PB/GB-SA) and RMSD fluctuations after MD simulations. The results demonstrated that 28 mutations out of 37 selected mutations analyzed, compared with wild-type N protein, resulted in a stable dimeric structure, while 9 mutations led to destabilization. Our results are important to understand the tertiary structure of the N protein dimer of SARS-CoV-2 and the effect of mutations on it, their behavior in the host cell, as well as for the research of other viruses belonging to the same genus additionally, to anticipate potential strategies for addressing this viral illness․.
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Affiliation(s)
- Nelli Muradyan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
| | - Vahram Arakelov
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
| | - Arsen Sargsyan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
- Russian-Armenian University, 0051, Yerevan, Armenia
| | - Adrine Paronyan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
- Russian-Armenian University, 0051, Yerevan, Armenia
| | - Grigor Arakelov
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia.
- Russian-Armenian University, 0051, Yerevan, Armenia.
| | - Karen Nazaryan
- Laboratory of Computational Modeling of Biological Processes, Institute of Molecular Biology of the National Academy of Sciences of the Republic of Armenia (NAS RA), 0014, Yerevan, Armenia
- Russian-Armenian University, 0051, Yerevan, Armenia
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Benning FMC, Jenni S, Garcia CY, Nguyen TH, Zhang X, Chao LH. Helical reconstruction of VP39 reveals principles for baculovirus nucleocapsid assembly. Nat Commun 2024; 15:250. [PMID: 38177118 PMCID: PMC10767040 DOI: 10.1038/s41467-023-44596-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
Baculoviruses are insect-infecting pathogens with wide applications as biological pesticides, in vitro protein production vehicles and gene therapy tools. Its cylindrical nucleocapsid, which encapsulates and protects the circular double-stranded viral DNA encoding proteins for viral replication and entry, is formed by the highly conserved major capsid protein VP39. The mechanism for VP39 assembly remains unknown. We use electron cryomicroscopy to determine a 3.2 Å helical reconstruction of an infectious nucleocapsid of Autographa californica multiple nucleopolyhedrovirus, revealing how dimers of VP39 assemble into a 14-stranded helical tube. We show that VP39 comprises a distinct protein fold conserved across baculoviruses, which includes a Zinc finger domain and a stabilizing intra-dimer sling. Analysis of sample polymorphism shows that VP39 assembles in several closely-related helical geometries. This VP39 reconstruction reveals general principles for baculoviral nucleocapsid assembly.
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Affiliation(s)
- Friederike M C Benning
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Coby Y Garcia
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Harvard College, Cambridge, MA, 02138, USA
| | - Tran H Nguyen
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Xuewu Zhang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Luke H Chao
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA.
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA.
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de Mello Malta F, Amgarten D, Marra AR, Petroni RC, da Silva Nali LH, Siqueira RA, Neto MC, Oler SC, Pinho JRR. Nucleocapsid single point-mutation associated with drop-out on RT-PCR assay for SARS-CoV-2 detection. BMC Infect Dis 2023; 23:714. [PMID: 37872472 PMCID: PMC10591358 DOI: 10.1186/s12879-023-08707-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/12/2023] [Indexed: 10/25/2023] Open
Abstract
BACKGROUND Since its beginning, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been a challenge for clinical and molecular diagnostics, because it has been caused by a novel viral agent. Whole-genome sequencing assisted in the characterization and classification of SARS-CoV-2, and it is an essential tool to genomic surveillance aiming to identify potentials hot spots that could impact on vaccine immune response and on virus diagnosis. We describe two cases of failure at the N2 target of the RT-PCR test Xpert® Xpress SARS-CoV-2. METHODS Total nucleic acid from the Nasopharyngeal (NP) and oropharyngeal (OP) swab samples and cell supernatant isolates were obtained. RNA samples were submitted to random amplification. Raw sequencing data were subjected to sequence quality controls, removal of human contaminants by aligning against the HG19 reference genome, taxonomic identification of other pathogens and genome recovery through assembly and manual curation. RT-PCR test Xpert® Xpress SARS-CoV-2 was used for molecular diagnosis of SARS-CoV-2 infection, samples were tested in duplicates. RESULTS We identified 27 samples positive for SARS-CoV-2 with a nucleocapsid (N) gene drop out on Cepheid Xpert® Xpress SARS-CoV-2 assay. Sequencing of 2 of 27 samples revealed a single common mutation in the N gene C29197T, potentially involved in the failed detection of N target. CONCLUSIONS This study highlights the importance of genomic data to update molecular tests and vaccines.
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Affiliation(s)
- Fernanda de Mello Malta
- Laboratório Clínico - Hospital Israelita Albert Einstein, Av. Albert Einstein, 627/701, Sao Paulo, SP, 05651-901, Brazil
| | - Deyvid Amgarten
- Laboratório Clínico - Hospital Israelita Albert Einstein, Av. Albert Einstein, 627/701, Sao Paulo, SP, 05651-901, Brazil
| | - Alexandre Rodrigues Marra
- Laboratório Clínico - Hospital Israelita Albert Einstein, Av. Albert Einstein, 627/701, Sao Paulo, SP, 05651-901, Brazil
| | - Roberta Cardoso Petroni
- Laboratório Clínico - Hospital Israelita Albert Einstein, Av. Albert Einstein, 627/701, Sao Paulo, SP, 05651-901, Brazil
| | - Luiz Henrique da Silva Nali
- Post-Graduation Program in Health Sciences, Santo Amaro University, Rua Prof. Enéas de Siqueira Neto, 340 - Jardim das Imbuias, Sao Paulo, SP, Brazil
| | - Ricardo Andreotti Siqueira
- Laboratório Clínico - Hospital Israelita Albert Einstein, Av. Albert Einstein, 627/701, Sao Paulo, SP, 05651-901, Brazil
| | - Miguel Cendoroglo Neto
- Laboratório Clínico - Hospital Israelita Albert Einstein, Av. Albert Einstein, 627/701, Sao Paulo, SP, 05651-901, Brazil
| | - Silvia Cassiano Oler
- Laboratório Clínico - Hospital Israelita Albert Einstein, Av. Albert Einstein, 627/701, Sao Paulo, SP, 05651-901, Brazil
| | - João Renato Rebello Pinho
- Laboratório Clínico - Hospital Israelita Albert Einstein, Av. Albert Einstein, 627/701, Sao Paulo, SP, 05651-901, Brazil.
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Gonnin L, Desfosses A, Bacia-Verloop M, Chevret D, Galloux M, Éléouët JF, Gutsche I. Structural landscape of the respiratory syncytial virus nucleocapsids. Nat Commun 2023; 14:5732. [PMID: 37714861 PMCID: PMC10504348 DOI: 10.1038/s41467-023-41439-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 09/01/2023] [Indexed: 09/17/2023] Open
Abstract
Human Respiratory Syncytial Virus (HRSV) is a prevalent cause of severe respiratory infections in children and the elderly. The helical HRSV nucleocapsid is a template for the viral RNA synthesis and a scaffold for the virion assembly. This cryo-electron microscopy analysis reveals the non-canonical arrangement of the HRSV nucleocapsid helix, composed of 16 nucleoproteins per asymmetric unit, and the resulting systematic variations in the RNA accessibility. We demonstrate that this unique helical symmetry originates from longitudinal interactions by the C-terminal arm of the HRSV nucleoprotein. We explore the polymorphism of the nucleocapsid-like assemblies, report five structures of the full-length particles and two alternative arrangements formed by a C-terminally truncated nucleoprotein mutant, and demonstrate the functional importance of the identified longitudinal interfaces. We put all these findings in the context of the HRSV RNA synthesis machinery and delineate the structural basis for its further investigation.
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Affiliation(s)
- Lorène Gonnin
- Institut de Biologie Structurale, Univ Grenoble Alpes, CEA, CNRS, IBS, 71 Avenue des martyrs, F-38044, Grenoble, France
- VIM, Paris-Saclay University, INRAE, 78350, Jouy-en-Josas, France
| | - Ambroise Desfosses
- Institut de Biologie Structurale, Univ Grenoble Alpes, CEA, CNRS, IBS, 71 Avenue des martyrs, F-38044, Grenoble, France.
| | - Maria Bacia-Verloop
- Institut de Biologie Structurale, Univ Grenoble Alpes, CEA, CNRS, IBS, 71 Avenue des martyrs, F-38044, Grenoble, France
| | - Didier Chevret
- VIM, Paris-Saclay University, INRAE, 78350, Jouy-en-Josas, France
| | - Marie Galloux
- VIM, Paris-Saclay University, INRAE, 78350, Jouy-en-Josas, France
| | | | - Irina Gutsche
- Institut de Biologie Structurale, Univ Grenoble Alpes, CEA, CNRS, IBS, 71 Avenue des martyrs, F-38044, Grenoble, France.
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5
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Wang Y, Zhang C, Luo Y, Ling X, Luo B, Jia G, Su D, Dong H, Su Z. Cryo-EM structure of the nucleocapsid-like assembly of respiratory syncytial virus. Signal Transduct Target Ther 2023; 8:323. [PMID: 37607909 PMCID: PMC10444854 DOI: 10.1038/s41392-023-01602-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 06/08/2023] [Accepted: 08/13/2023] [Indexed: 08/24/2023] Open
Abstract
Respiratory syncytial virus (RSV) is a nonsegmented, negative strand RNA virus that has caused severe lower respiratory tract infections of high mortality rates in infants and the elderly, yet no effective vaccine or antiviral therapy is available. The RSV genome encodes the nucleoprotein (N) that forms helical assembly to encapsulate and protect the RNA genome from degradation, and to serve as a template for transcription and replication. Previous crystal structure revealed a decameric ring architecture of N in complex with the cellular RNA (N-RNA) of 70 nucleotides (70-nt), whereas cryo-ET reconstruction revealed a low-resolution left-handed filament, in which the crystal monomer structure was docked with the helical symmetry applied to simulate a nucleocapsid-like assembly of RSV. However, the molecular details of RSV nucleocapsid assembly remain unknown, which continue to limit our complete understanding of the critical interactions involved in the nucleocapsid and antiviral development that may target this essential process during the viral life cycle. Here we resolve the near-atomic cryo-EM structure of RSV N-RNA that represents roughly one turn of the helical assembly that unveils critical interaction interfaces of RSV nucleocapsid and may facilitate development of RSV antiviral therapy.
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Affiliation(s)
- Yan Wang
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Chong Zhang
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Yongbo Luo
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Xiaobin Ling
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Bingnan Luo
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Guowen Jia
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Dan Su
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Haohao Dong
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China
| | - Zhaoming Su
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, 610044, China.
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Hu J, Wang H, Yang L, Wu S, Li Y, Li Y, Li Z. Compound IMB-Z inhibits hepatitis B virus replication through increasing APOBEC3G expression and incorporation into viral nucleocapsids. J Glob Antimicrob Resist 2022; 31:371-378. [PMID: 36396043 DOI: 10.1016/j.jgar.2022.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 09/01/2022] [Accepted: 11/04/2022] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES As a host restriction factor, apolipoprotein B messenger RNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G or A3G) has been shown to suppress the replication of several viruses including hepatitis B virus (HBV). Recently, we reported that IMB-Z, a N-phenylbenzamide derivative, could inhibit Enterovirus 71 replication, and A3G mediated its antiviral activity. Whether IMB-Z exhibits an inhibitory effect on HBV replication has not been investigated. MATERIAL AND METHODS HBV DNA, pregenomic RNA (pgRNA), core protein, and capsid levels were determined by a qPCR assay or Southern blot, Northern blot, Western blot, and particle gel assay, respectively. Mutation analysis of HBV DNAs was conducted by a differential DNA denaturation PCR assay. A3G encapsidation into HBV nucleocapsids was examined by Western blot analysis after ultracentrifugation and a co-immunoprecipitation (IP) assay between HBV core and A3G proteins. RESULTS In the present study, we found that IMB-Z could considerably inhibit HBV replication in HepAD38 cells. Interestingly, IMB-Z did not alter the HBV pgRNA production but could reduce the level of core protein, viral nucleocapsids, and core-associated DNA, as well as cccDNA intracellular amplification. Similar to the action of IMB-Z's inhibition of Enterovirus 71 replication, we found that IMB-Z's inhibition of HBV replication was associated with increased level of A3G. Mechanistically, we demonstrated that the inhibitory effect of IMB-Z is independent of the cytidine deaminase activity of A3G and is exerted by increasing its incorporation into viral nucleocapsids. CONCLUSIONS Our results indicate that IMB-Z inhibits HBV through pharmacological induction A3G expression and incorporation into HBV nucleocapsids.
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Affiliation(s)
- Jin Hu
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Huiqiang Wang
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lu Yang
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shuo Wu
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Yanping Li
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Yuhuan Li
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Zhuorong Li
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Xi J, Cui X, Liu K, Liu H, Wang J, Hu J. Region-Specific Hepatitis B Virus Genome Exposure from Nucleocapsid Modulated by Capsid Linker Sequence and Inhibitor: Implications for Uncoating. J Virol 2022; 96:e0039922. [PMID: 35389266 PMCID: PMC9044944 DOI: 10.1128/jvi.00399-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 03/09/2022] [Indexed: 11/20/2022] Open
Abstract
Hepatitis B virus (HBV) contains a partially double-stranded, relaxed circular (RC) DNA genome synthesized within a nucleocapsid (NC) in the host cell cytoplasm. The release of RC DNA from the NC, in an ill-defined process called uncoating, to the nucleus is required for its conversion to the covalently closed circular (CCC) DNA, the viral episome serving as the transcriptional template for all viral RNAs necessary for replication and, thus, essential for establishing and sustaining viral infection. In efforts to better understand uncoating, we analyzed HBV core (HBc) mutants that show various levels of nuclear CCC DNA but little to no cytoplasmic RC DNA. We found that RC DNA could be synthesized by these mutants outside the cell, but in contrast to the wild type (wt), the mutant NCs were unable to protect RC DNA from digestion by the endogenous nuclease(s) in cellular lysates or exogenous DNase. Subcellular fractionation suggested that the major RC DNA-degrading activity was membrane associated. Digestion with sequence-specific and nonspecific DNases revealed the exposure of specific regions of RC DNA from the mutant NC. Similarly, treatment of wt NCs with a core inhibitor known to increase CCC DNA by affecting uncoating also led to region-specific exposure of RC DNA. Furthermore, a subpopulation of untreated wild type (wt) mature NCs showed site-specific exposure of RC DNA as well. Competition between RC DNA degradation and its conversion to CCC DNA during NC uncoating thus likely plays an important role in the establishment and persistence of HBV infection and has implications for the development of capsid-targeted antivirals. IMPORTANCE Disassembly of the hepatitis B virus (HBV) nucleocapsid (NC) to release its genomic DNA, in an ill-understood process called uncoating, is required to form the viral nuclear episome in the host cell nucleus, a viral DNA essential for establishing and sustaining HBV infection. The elimination of the HBV nuclear episome remains the holy grail for the development of an HBV cure. We report here that the HBV genomic DNA is exposed in a region-specific manner during uncoating, which is enhanced by mutations of the capsid protein and a capsid-targeted antiviral compound. The exposure of the viral genome can result in its rapid degradation or, alternatively, can enhance the formation of the nuclear episome, thus having a major impact on HBV infection and persistence. These results are thus important for understanding fundamental mechanisms of HBV replication and persistence and for the ongoing pursuit of an HBV cure.
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Affiliation(s)
- Ji Xi
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Xiuji Cui
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Kuancheng Liu
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Haitao Liu
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Joseph Wang
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Jianming Hu
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
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Chaminade F, Darlix JL, Fossé P. RNA Structural Requirements for Nucleocapsid Protein-Mediated Extended Dimer Formation. Viruses 2022; 14:606. [PMID: 35337013 PMCID: PMC8953772 DOI: 10.3390/v14030606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 11/16/2022] Open
Abstract
Retroviruses package two copies of their genomic RNA (gRNA) as non-covalently linked dimers. Many studies suggest that the retroviral nucleocapsid protein (NC) plays an important role in gRNA dimerization. The upper part of the L3 RNA stem-loop in the 5' leader of the avian leukosis virus (ALV) is converted to the extended dimer by ALV NC. The L3 hairpin contains three stems and two internal loops. To investigate the roles of internal loops and stems in the NC-mediated extended dimer formation, we performed site-directed mutagenesis, gel electrophoresis, and analysis of thermostability of dimeric RNAs. We showed that the internal loops are necessary for efficient extended dimer formation. Destabilization of the lower stem of L3 is necessary for RNA dimerization, although it is not involved in the linkage structure of the extended dimer. We found that NCs from ALV, human immunodeficiency virus type 1 (HIV-1), and Moloney murine leukemia virus (M-MuLV) cannot promote the formation of the extended dimer when the apical stem contains ten consecutive base pairs. Five base pairs correspond to the maximum length for efficient L3 dimerization induced by the three NCs. L3 dimerization was less efficient with M-MuLV NC than with ALV NC and HIV-1 NC.
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Affiliation(s)
- Françoise Chaminade
- LBPA, UMR8113 CNRS, ENS Paris-Saclay, Université Paris-Saclay, 91190 Gif-sur-Yvette, France;
| | - Jean-Luc Darlix
- Laboratoire de Bioimagerie et Pathologies, UMR7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 67400 Illkirch, France;
| | - Philippe Fossé
- LBPA, UMR8113 CNRS, ENS Paris-Saclay, Université Paris-Saclay, 91190 Gif-sur-Yvette, France;
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Gupta RS, Khadka B. Conserved Molecular Signatures in the Spike, Nucleocapsid, and Polymerase Proteins Specific for the Genus Betacoronavirus and Its Different Subgenera. Genes (Basel) 2022; 13:genes13030423. [PMID: 35327976 PMCID: PMC8949385 DOI: 10.3390/genes13030423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 02/04/2023] Open
Abstract
The genus Betacoronavirus, consisting of four main subgenera (Embecovirus, Merbecovirus, Nobecovirus, and Sarbecovirus), encompasses all clinically significant coronaviruses (CoVs), including SARS, MERS, and the SARS-CoV-2 virus responsible for current COVID-19 pandemic. Very few molecular characteristics are known that are specific for the genus Betacoronavirus or its different subgenera. In this study, our analyses of the sequences of four essential proteins of CoVs, viz., spike, nucleocapsid, envelope, and RNA-dependent RNA polymerase (RdRp), identified ten novel molecular signatures consisting of conserved signature indels (CSIs) in these proteins which are specific for the genus Betacoronavirus or its subgenera. Of these CSIs, two 14-aa-conserved deletions found within the heptad repeat motifs 1 and 2 of the spike protein are specific for all betacoronaviruses, except for their shared presence in the highly infectious avian coronavirus. Six additional CSIs present in the nucleocapsid protein and one CSI in the RdRp protein are distinctive characteristics of either the Merbecovirus, Nobecovirus, or Sarbecovirus subgenera. In addition, a 4-aa insert is present in the spike protein, which is uniquely shared by all viruses from the subgenera Merbecovirus, Nobecovirus, and Sarbecovirus, but absent in Embecovirus and all other genera of CoVs. This molecular signature provides evidence that viruses from the three subgenera sharing this CSI are more closely related to each other, and they evolved after the divergence of embecoviruses and other CoVs. As all CSIs specific for different groups of CoVs are flanked by conserved regions, their sequences provide novel means for identifying the above groups of CoVs and for developing novel diagnostic tests. Furthermore, our analyses of the structures of the spike and nucleocapsid proteins show that all identified CSIs are localized in the surface-exposed loops of these protein. It is postulated that these surface loops, through their interactions with other cellular proteins/ligands, play important roles in the biology/pathology of these viruses.
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Affiliation(s)
- Radhey S. Gupta
- Department of Biochemistry and Biomedical Sciences McMaster University, Hamilton, ON L8N 3Z5, Canada
- Correspondence:
| | - Bijendra Khadka
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada;
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Yang Y, Yan Y, Yin J, Hu J, Cai X, Hu J, Xia J, Wang K, Tang N, Huang L. Structure-Based Discovery of N-Sulfonylpiperidine-3-carboxamides as Novel Capsid Assembly Modulators for Potent Inhibition of HBV Replication. Viruses 2022; 14:v14020348. [PMID: 35215939 PMCID: PMC8876525 DOI: 10.3390/v14020348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/31/2022] [Accepted: 01/31/2022] [Indexed: 12/03/2022] Open
Abstract
As a key element during HBV replication, a nucleocapsid is considered a promising target for the treatment of chronic hepatitis B. The present study aimed to identify small molecules as novel capsid assembly modulators with antiviral activity. Structure-based virtual screening of an integrated compound library led to the identification of several types of HBV inhibitors. Among these inhibitors, N-sulfonylpiperidine-3-carboxamides (SPCs) potently reduced the amount of secreted HBV DNA. Through structure–activity relationship studies, we identified an SPC derivative, namely, C-39, which exhibited the highest antiviral activity without causing cytotoxicity. Mechanism studies showed that C-39 dose-dependently inhibited the formation of HBV capsid, synthesis of cccDNA, e antigen (HBeAg), viral pregenomic RNA (pgRNA), and HBV DNA levels, thereby restraining HBV replication. In summary, SPCs represent a new class of capsid assembly modulators. Further optimization of SPCs is expected to obtain new antiviral drugs against HBV infection.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Ni Tang
- Correspondence: (N.T.); (L.H.)
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11
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Cascarina SM, Ross ED. Phase separation by the SARS-CoV-2 nucleocapsid protein: Consensus and open questions. J Biol Chem 2022; 298:101677. [PMID: 35131265 PMCID: PMC8813722 DOI: 10.1016/j.jbc.2022.101677] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 01/09/2023] Open
Abstract
In response to the recent SARS-CoV-2 pandemic, a number of labs across the world have reallocated their time and resources to better our understanding of the virus. For some viruses, including SARS-CoV-2, viral proteins can undergo phase separation: a biophysical process often related to the partitioning of protein and RNA into membraneless organelles in vivo. In this review, we discuss emerging observations of phase separation by the SARS-CoV-2 nucleocapsid (N) protein-an essential viral protein required for viral replication-and the possible in vivo functions that have been proposed for N-protein phase separation, including viral replication, viral genomic RNA packaging, and modulation of host-cell response to infection. Additionally, since a relatively large number of studies examining SARS-CoV-2 N-protein phase separation have been published in a short span of time, we take advantage of this situation to compare results from similar experiments across studies. Our evaluation highlights potential strengths and pitfalls of drawing conclusions from a single set of experiments, as well as the value of publishing overlapping scientific observations performed simultaneously by multiple labs.
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Affiliation(s)
- Sean M Cascarina
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Eric D Ross
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA.
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12
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Mourier T, Shuaib M, Hala S, Mfarrej S, Alofi F, Naeem R, Alsomali A, Jorgensen D, Subudhi AK, Ben Rached F, Guan Q, Salunke RP, Ooi A, Esau L, Douvropoulou O, Nugmanova R, Perumal S, Zhang H, Rajan I, Al-Omari A, Salih S, Shamsan A, Al Mutair A, Taha J, Alahmadi A, Khotani N, Alhamss A, Mahmoud A, Alquthami K, Dageeg A, Khogeer A, Hashem AM, Moraga P, Volz E, Almontashiri N, Pain A. SARS-CoV-2 genomes from Saudi Arabia implicate nucleocapsid mutations in host response and increased viral load. Nat Commun 2022; 13:601. [PMID: 35105893 PMCID: PMC8807822 DOI: 10.1038/s41467-022-28287-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 01/12/2022] [Indexed: 02/06/2023] Open
Abstract
Monitoring SARS-CoV-2 spread and evolution through genome sequencing is essential in handling the COVID-19 pandemic. Here, we sequenced 892 SARS-CoV-2 genomes collected from patients in Saudi Arabia from March to August 2020. We show that two consecutive mutations (R203K/G204R) in the nucleocapsid (N) protein are associated with higher viral loads in COVID-19 patients. Our comparative biochemical analysis reveals that the mutant N protein displays enhanced viral RNA binding and differential interaction with key host proteins. We found increased interaction of GSK3A kinase simultaneously with hyper-phosphorylation of the adjacent serine site (S206) in the mutant N protein. Furthermore, the host cell transcriptome analysis suggests that the mutant N protein produces dysregulated interferon response genes. Here, we provide crucial information in linking the R203K/G204R mutations in the N protein to modulations of host-virus interactions and underline the potential of the nucleocapsid protein as a drug target during infection.
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Affiliation(s)
- Tobias Mourier
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Muhammad Shuaib
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Sharif Hala
- Infectious Disease Research Department, King Abdullah International Medical Research Centre, Ministry of National Guard Health Affairs, Jeddah, Saudi Arabia
- King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Jeddah, Saudi Arabia
| | - Sara Mfarrej
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Fadwa Alofi
- Infectious Diseases Department, King Fahad Hospital, Madinah, MOH, Saudi Arabia
| | - Raeece Naeem
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Afrah Alsomali
- Infectious Diseases Department, King Abdullah Medical Complex, Jeddah, MOH, Saudi Arabia
| | - David Jorgensen
- School of Public Health, Faculty of Medicine, Imperial College, Norfolk Place, St Mary's Campus, London, United Kingdom
| | - Amit Kumar Subudhi
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Fathia Ben Rached
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Qingtian Guan
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Rahul P Salunke
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Amanda Ooi
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Luke Esau
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Olga Douvropoulou
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Raushan Nugmanova
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Sadhasivam Perumal
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Huoming Zhang
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Issaac Rajan
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Awad Al-Omari
- Dr. Suliman Al-Habib Medical Group, Riyadh, Saudi Arabia
| | - Samer Salih
- Dr. Suliman Al-Habib Medical Group, Riyadh, Saudi Arabia
| | - Abbas Shamsan
- Dr. Suliman Al-Habib Medical Group, Riyadh, Saudi Arabia
| | | | - Jumana Taha
- Department of Neuroscience, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Abdulaziz Alahmadi
- Department of Preventive Medicine, Ministry of National Guard - Health Affairs, Riyadh, Saudi Arabia
| | - Nashwa Khotani
- Infectious Diseases Medical Department, Al Noor Specialist Hospital Makkah, Makkah, MOH, Saudi Arabia
| | - Abdelrahman Alhamss
- Gastroenterology Department, King Abdul Aziz Hospital Makkah, Makkah, MOH, Saudi Arabia
| | - Ahmed Mahmoud
- College of Applied Medical Sciences, Taibah University, Madinah, Saudi Arabia
| | - Khaled Alquthami
- Infectious Diseases Medical Department, Al Noor Specialist Hospital Makkah, Makkah, MOH, Saudi Arabia
| | - Abdullah Dageeg
- Department of Medicine, King Abdulaziz University Jeddah, Jeddah, Saudi Arabia
| | - Asim Khogeer
- Plan and Research Department, General Directorate of Health Affairs Makkah Region, Makkah, MOH, Saudi Arabia
| | - Anwar M Hashem
- Vaccines and Immunotherapy Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Paula Moraga
- King Abdullah University of Science and Technology (KAUST), Computer, Electrical and Mathematical Science and Engineering Division (CEMSE), Thuwal-Jeddah, 23955-6900, Saudi Arabia
| | - Eric Volz
- School of Public Health, Faculty of Medicine, Imperial College, Norfolk Place, St Mary's Campus, London, United Kingdom
| | - Naif Almontashiri
- College of Applied Medical Sciences, Taibah University, Madinah, Saudi Arabia
- Center for Genetics and Inherited Diseases, Taibah University, Almadinah Almunwarah, Saudi Arabia
| | - Arnab Pain
- King Abdullah University of Science and Technology (KAUST), Pathogen Genomics Laboratory, Biological and Environmental Science and Engineering (BESE), Thuwal-Jeddah, 23955-6900, Saudi Arabia.
- Research Center for Zoonosis Control, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, N20 W10 Kita-ku, Sapporo, 001-0020, Japan.
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13
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Maus A, Renuse S, Kemp J, Madugundu AK, Vanderboom PM, Blommel J, Jerde C, Dasari S, Kipp BR, Singh RJ, Grebe SK, Pandey A. Targeted Detection of SARS-CoV-2 Nucleocapsid Sequence Variants by Mass Spectrometric Analysis of Tryptic Peptides. J Proteome Res 2022; 21:142-150. [PMID: 34779632 PMCID: PMC8610007 DOI: 10.1021/acs.jproteome.1c00613] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Indexed: 12/24/2022]
Abstract
COVID-19 vaccines are becoming more widely available, but accurate and rapid testing remains a crucial tool for slowing the spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus. Although the quantitative reverse transcription-polymerase chain reaction (qRT-PCR) remains the most prevalent testing methodology, numerous tests have been developed that are predicated on detection of the SARS-CoV-2 nucleocapsid protein, including liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassay-based approaches. The continuing emergence of SARS-CoV-2 variants has complicated these approaches, as both qRT-PCR and antigen detection methods can be prone to missing viral variants. In this study, we describe several COVID-19 cases where we were unable to detect the expected peptide targets from clinical nasopharyngeal swabs. Whole genome sequencing revealed that single nucleotide polymorphisms in the gene encoding the viral nucleocapsid protein led to sequence variants that were not monitored in the targeted assay. Minor modifications to the LC-MS/MS method ensured detection of the variants of the target peptide. Additional nucleocapsid variants could be detected by performing the bottom-up proteomic analysis of whole viral genome-sequenced samples. This study demonstrates the importance of considering variants of SARS-CoV-2 in the assay design and highlights the flexibility of mass spectrometry-based approaches to detect variants as they evolve.
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Affiliation(s)
- Anthony Maus
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Santosh Renuse
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
- Center
for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Jennifer Kemp
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Anil K. Madugundu
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
- Institute
of Bioinformatics, International Technology
Park, Bangalore 560066, Karnataka, India
- Manipal
Academy of Higher Education, Manipal 576104, Karnataka, India
- Center
for Molecular Medicine, National Institute
of Mental Health and Neurosciences, Hosur Road, Bangalore 560029, Karnataka, India
| | - Patrick M. Vanderboom
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Joseph Blommel
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Calvin Jerde
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Surendra Dasari
- Division
of Biomedical Statistics and Informatics, Department of Health Sciences
Research, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Benjamin R. Kipp
- Department
of Laboratory Medicine and Pathology, Division of Laboratory Genetics
and Genomics, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Ravinder J. Singh
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
| | - Stefan K. Grebe
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
- Department
of Medicine, Division of Endocrinology, Mayo Clinic, Rochester, Minnesota 55902, United States
| | - Akhilesh Pandey
- Department
of Laboratory Medicine and Pathology, Division of Clinical Biochemistry
and Immunology, Mayo Clinic, Rochester, Minnesota 55905, United States
- Center
for Individualized Medicine, Mayo Clinic, Rochester, Minnesota 55905, United States
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14
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Sukumaran A, Suvekbala V, R AK, Thomas RE, Raj A, Thomas T, Abhijith B, Jose J, Paul JK, Vasudevan D. OUP accepted manuscript. J Appl Lab Med 2022; 7:871-880. [PMID: 35689333 PMCID: PMC9214153 DOI: 10.1093/jalm/jfac023] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/08/2022] [Indexed: 11/22/2022]
Abstract
Background Currently, the rapid antigen test (RAT) and reverse transcriptase–polymerase chain reaction (RT–PCR) are considered the main stakeholders in COVID-19 diagnosis. In RT–PCR, any of at least 2 evolutionary conserved genes (RdRP, E-, N-, ORF1ab gene) and S-gene of SARS-CoV-2 are endorsed, and in RAT, the nucleocapsid antigen (N-Ag) of SARS-CoV-2 is considered due to its stability and fewer chances of mutation effects. In the present work, we evaluated the performance of the AG-Q COVID-19 N-Ag self-test kit and conducted a validation study in comparison with the RT–PCR. Methods AG-Q COVID-19 N-Ag rapid test kit is an Indian Council of Medical Research (ICMR) approved product developed and marketed by Agappe Diagnostics Limited. The RT–PCR assay was performed with a COVIPATH COVID-19 RT–PCR kit from Thermo Fisher Scientific. Results We observed 19 false-negative results in antigen self-tests, including samples of threshold cycle (Ct) values 22/22 (N-gene/ORF1ab-gene) in RT–PCR, indicating inadequate sampling by the patients in self-tests, leading to false-negative results and increased chances of the disease spreading. Based on the RT–PCR Ct value vs antigen self-test comparison, it is evident that proper sampling is crucial in performing antigen self-tests. Also, there were weak positive results in antigen self-tests with a Ct value of 18/19 in RT–PCR. Conclusions Although the sensitivity and diagnostic accuracy offered by the AG-Q COVID-19 N-Antigen self-test in comparison with RT–PCR fulfills the ICMR tenets for RAT, this study recommends the laboratory/hospital-based RAT execution would be appropriate, rather than the self-test.
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Affiliation(s)
- Ajaikumar Sukumaran
- Address correspondence to this author at: Assistant Manager (R&D), Agappe Diagnostics Limited, Agappe Hills, Pattimattom P O, Ernakulam, Kerala, India. E-mail ,
| | | | - Arun Krishnan R
- Research & Development (Reagent) Department, Agappe Diagnostics Limited, Agappe Hills, Pattimattom P O, Ernakulam, Kerala, India
| | - Rhema Elizabeth Thomas
- Research & Development (Reagent) Department, Agappe Diagnostics Limited, Agappe Hills, Pattimattom P O, Ernakulam, Kerala, India
| | - Aneesh Raj
- Genetics & Molecular Diagnostics Laboratory, Noorul Islam Institute of Medical Science & Research Foundation (NIMS), Trivandrum, Kerala, India
| | - Thushara Thomas
- Research & Development (Reagent) Department, Agappe Diagnostics Limited, Agappe Hills, Pattimattom P O, Ernakulam, Kerala, India
| | - B.L. Abhijith
- Research & Development (Reagent) Department, Agappe Diagnostics Limited, Agappe Hills, Pattimattom P O, Ernakulam, Kerala, India
| | - Jisha Jose
- Research & Development (Reagent) Department, Agappe Diagnostics Limited, Agappe Hills, Pattimattom P O, Ernakulam, Kerala, India
| | - Jofy K. Paul
- Research & Development (Reagent) Department, Agappe Diagnostics Limited, Agappe Hills, Pattimattom P O, Ernakulam, Kerala, India
| | - D.M. Vasudevan
- Research & Development (Reagent) Department, Agappe Diagnostics Limited, Agappe Hills, Pattimattom P O, Ernakulam, Kerala, India
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15
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Wu C, Qavi AJ, Moyle AB, Wagner ND, Hachim A, Kavian N, Cole AR, Sweeney-Gibbons J, Rohrs HW, Peiris JM, Basler CF, Gross ML, Valkenburg SA, Farnsworth CW, Amarasinghe GK, Leung DW. Domain-specific biochemical and serological characterization of SARS-CoV-2 nucleocapsid protein. STAR Protoc 2021; 2:100906. [PMID: 34642671 PMCID: PMC8495048 DOI: 10.1016/j.xpro.2021.100906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Nucleocapsid proteins are essential for SARS-CoV-2 life cycle. Here, we describe protocols to gather domain-specific insights about essential properties of nucleocapsids. These assays include dynamic light scattering to characterize oligomerization, fluorescence polarization to quantify RNA binding, hydrogen-deuterium exchange mass spectrometry to map RNA binding regions, negative-stain electron microscopy to visualize oligomeric species, interferon reporter assay to evaluate interferon signaling modulation, and a serology assay to reveal insights for improved sensitivity and specificity. These assays are broadly applicable to RNA-encapsidated nucleocapsids. For complete details on the use and execution of this protocol, please refer to Wu et al. (2021).
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Affiliation(s)
- Chao Wu
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Abraham J. Qavi
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Austin B. Moyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Nicole D. Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Asmaa Hachim
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Niloufar Kavian
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Assistance Publique–Hôpitaux de Paris, Hôpital Universitaire Paris Centre, Centre Hospitalier Universitaire Cochin, Service d’Immunologie Biologique, Paris, France
- Institut Cochin, INSERM U1016, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Aidan R. Cole
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Joyce Sweeney-Gibbons
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Henry W. Rohrs
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - J.S. Malik Peiris
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
- Division of Public Health Laboratory Sciences, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Christopher F. Basler
- Center for Microbial Pathogenesis, Institute for Biomedical Sciences, Georgia State University, Atlanta, GA 30303, USA
| | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Sophie A. Valkenburg
- HKU-Pasteur Research Pole, School of Public Health, The University of Hong Kong, Hong Kong, China
| | - Christopher W. Farnsworth
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Gaya K. Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Daisy W. Leung
- Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
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16
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Amato L, Jurisic L, Puglia I, Di Lollo V, Curini V, Torzi G, Di Girolamo A, Mangone I, Mancinelli A, Decaro N, Calistri P, Di Giallonardo F, Lorusso A, D’Alterio N. Multiple detection and spread of novel strains of the SARS-CoV-2 B.1.177 (B.1.177.75) lineage that test negative by a commercially available nucleocapsid gene real-time RT-PCR. Emerg Microbes Infect 2021; 10:1148-1155. [PMID: 34019466 PMCID: PMC8205086 DOI: 10.1080/22221751.2021.1933609] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/13/2021] [Accepted: 05/16/2021] [Indexed: 01/24/2023]
Abstract
Several lineages of SARS-CoV-2 are currently circulating worldwide. During SARS-CoV-2 diagnostic activities performed in Abruzzo region (central Italy) several strains belonging to the B.1.177.75 lineage tested negative for the N gene but positive for the ORF1ab and S genes (+/+/- pattern) by the TaqPath COVID-19 CE-IVD RT-PCR Kit manufactured by Thermofisher. By sequencing, a unique mutation, synonymous 28948C > T, was found in the N-negative B.1.177.75 strains. Although we do not have any knowledge upon the nucleotide sequences of the primers and probe adopted by this kit, it is likely that N gene dropout only occurs when 28948C > T is coupled with 28932C > T, this latter present, in turn, in all B.1.177.75 sequences available on public databases. Furthermore, epidemiological analysis was also performed. The majority of the N-negative B.1.177.75 cases belonged to two clusters apparently unrelated to each other and both clusters involved young people. However, the phylogeny for sequences containing the +/+/- pattern strongly supports a genetic connection and one common source for both clusters. Though, genetic comparison suggests a connection rather than indicating the independent emergence of the same mutation in two apparently unrelated clusters. This study highlights once more the importance of sharing genomic data to link apparently unrelated epidemiological clusters and to, remarkably, update molecular tests.
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Affiliation(s)
- Laura Amato
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
| | - Lucija Jurisic
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
- Faculty of Veterinary Medicine, Università degli Studi di Teramo, Teramo, Italy
| | - Ilaria Puglia
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
| | - Valeria Di Lollo
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
| | - Valentina Curini
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
| | - Giuseppe Torzi
- Azienda Sanitaria Locale, Lanciano-Vasto-Chieti, Chieti, Italy
| | | | - Iolanda Mangone
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
| | | | - Nicola Decaro
- Department of Veterinary Medicine, University of Bari Aldo Moro, Valenzano (Bari), Italy
| | - Paolo Calistri
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
| | | | - Alessio Lorusso
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
| | - Nicola D’Alterio
- Istituto Zooprofilattico Sperimentale dell’Abruzzo e Molise (IZSAM), Teramo, Italy
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17
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Bezstarosti K, Lamers MM, Doff WAS, Wever PC, Thai KTD, van Kampen JJA, Haagmans BL, Demmers JAA. Targeted proteomics as a tool to detect SARS-CoV-2 proteins in clinical specimens. PLoS One 2021; 16:e0259165. [PMID: 34762662 PMCID: PMC8584957 DOI: 10.1371/journal.pone.0259165] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 10/13/2021] [Indexed: 01/22/2023] Open
Abstract
The rapid, sensitive and specific detection of SARS-CoV-2 is critical in responding to the current COVID-19 outbreak. In this proof-of-concept study, we explored the potential of targeted mass spectrometry (MS) based proteomics for the detection of SARS-CoV-2 proteins in both research samples and clinical specimens. First, we assessed the limit of detection for several SARS-CoV-2 proteins by parallel reaction monitoring (PRM) MS in infected Vero E6 cells. For tryptic peptides of Nucleocapsid protein, the limit of detection was estimated to be in the mid-attomole range (9E-13 g). Next, this PRM methodology was applied to the detection of viral proteins in various COVID-19 patient clinical specimens, such as sputum and nasopharyngeal swabs. SARS-CoV-2 proteins were detected in these samples with high sensitivity in all specimens with PCR Ct values <24 and in several samples with higher CT values. A clear relationship was observed between summed MS peak intensities for SARS-CoV-2 proteins and Ct values reflecting the abundance of viral RNA. Taken together, these results suggest that targeted MS based proteomics may have the potential to be used as an additional tool in COVID-19 diagnostics.
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Affiliation(s)
- Karel Bezstarosti
- Proteomics Center, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Mart M. Lamers
- Viroscience Department, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Wouter A. S. Doff
- Proteomics Center, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Peter C. Wever
- Jeroen Bosch Hospital, ‘s-Hertogenbosch, the Netherlands
| | - Khoa T. D. Thai
- Star-shl Medical Diagnostic Center, Rotterdam, the Netherlands
| | | | - Bart L. Haagmans
- Viroscience Department, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Jeroen A. A. Demmers
- Proteomics Center, Erasmus University Medical Center, Rotterdam, the Netherlands
- * E-mail:
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18
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Bourassa L, Perchetti GA, Phung Q, Lin MJ, Mills MG, Roychoudhury P, Harmon KG, Reed JC, Greninger AL. A SARS-CoV-2 Nucleocapsid Variant that Affects Antigen Test Performance. J Clin Virol 2021; 141:104900. [PMID: 34171548 DOI: 10.1101/2021.05.05.21256527] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/09/2021] [Indexed: 05/27/2023]
Abstract
More than one year into a global pandemic, SARS-CoV-2 is now defined by a variety of rapidly evolving variant lineages. Several FDA authorized molecular diagnostic tests have been impacted by viral variation, while no reports of viral variation affecting antigen test performance have occurred to date. While determining the analytical sensitivity of the Quidel Sofia SARS Antigen FIA test (Sofia 2), we uncovered a high viral load specimen that repeatedly tested negative by this antigen test. Whole genome sequencing of the specimen uncovered two mutations, T205I and D399N, present in the nucleocapsid protein of the isolate. All six SARS-CoV-2 positive clinical specimens available in our laboratory with a D399N nucleocapsid mutation and CT < 31 were not detected by the Sofia 2 but detected by the Abbott BinaxNOW COVID-19 Ag Card, while clinical specimens with the T205I mutation were detected by both assays. Testing of recombinant SARS-CoV-2 nucleocapsid with these variants demonstrated an approximate 1000-fold loss in sensitivity for the Quidel Sofia SARS Antigen FIA test associated with the D399N mutation, while the BinaxNOW and Quidel Quickvue SARS Antigen tests were unaffected by the mutation. The D399N nucleocapsid mutation has been relatively uncommon to date, appearing in only 0.02% of genomes worldwide at time of writing. Our results demonstrate how routine pathogen genomics can be integrated into the clinical microbiology laboratory to investigate diagnostic edge cases, as well as the importance of profiling antigenic diversity outside of the spike protein for SARS-CoV-2 diagnostics.
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Affiliation(s)
- Lori Bourassa
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Garrett A Perchetti
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Quynh Phung
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Michelle J Lin
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Margaret G Mills
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Pavitra Roychoudhury
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA; Viral and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Kimberly G Harmon
- Department of Family Medicine, for Stanley Herring Department of Physical Medicine and Rehabilitation, University of Washington, Seattle, Washington, USA
| | - Jonathan C Reed
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Alexander L Greninger
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA; Viral and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
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19
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Voss C, Esmail S, Liu X, Knauer MJ, Ackloo S, Kaneko T, Lowes L, Stogios P, Seitova A, Hutchinson A, Yusifov F, Skarina T, Evdokimova E, Loppnau P, Ghiabi P, Haijan T, Zhong S, Abdoh H, Hedley BD, Bhayana V, Martin CM, Slessarev M, Chin-Yee B, Fraser DD, Chin-Yee I, Li SS. Epitope-specific antibody responses differentiate COVID-19 outcomes and variants of concern. JCI Insight 2021; 6:148855. [PMID: 34081630 PMCID: PMC8410046 DOI: 10.1172/jci.insight.148855] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 06/02/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUNDThe role of humoral immunity in COVID-19 is not fully understood, owing, in large part, to the complexity of antibodies produced in response to the SARS-CoV-2 infection. There is a pressing need for serology tests to assess patient-specific antibody response and predict clinical outcome.METHODSUsing SARS-CoV-2 proteome and peptide microarrays, we screened 146 COVID-19 patients' plasma samples to identify antigens and epitopes. This enabled us to develop a master epitope array and an epitope-specific agglutination assay to gauge antibody responses systematically and with high resolution.RESULTSWe identified linear epitopes from the spike (S) and nucleocapsid (N) proteins and showed that the epitopes enabled higher resolution antibody profiling than the S or N protein antigen. Specifically, we found that antibody responses to the S-811-825, S-881-895, and N-156-170 epitopes negatively or positively correlated with clinical severity or patient survival. Moreover, we found that the P681H and S235F mutations associated with the coronavirus variant of concern B.1.1.7 altered the specificity of the corresponding epitopes.CONCLUSIONEpitope-resolved antibody testing not only affords a high-resolution alternative to conventional immunoassays to delineate the complex humoral immunity to SARS-CoV-2 and differentiate between neutralizing and non-neutralizing antibodies, but it also may potentially be used to predict clinical outcome. The epitope peptides can be readily modified to detect antibodies against variants of concern in both the peptide array and latex agglutination formats.FUNDINGOntario Research Fund (ORF) COVID-19 Rapid Research Fund, Toronto COVID-19 Action Fund, Western University, Lawson Health Research Institute, London Health Sciences Foundation, and Academic Medical Organization of Southwestern Ontario (AMOSO) Innovation Fund.
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MESH Headings
- Agglutination Tests/methods
- Amino Acid Sequence
- Antibodies, Neutralizing/blood
- Antibodies, Neutralizing/immunology
- Antibodies, Viral/blood
- Antibodies, Viral/immunology
- Antibody Formation/immunology
- Antibody Specificity/immunology
- COVID-19/blood
- COVID-19/immunology
- COVID-19/mortality
- COVID-19 Serological Testing/methods
- Epitopes/immunology
- Epitopes, B-Lymphocyte/chemistry
- Epitopes, B-Lymphocyte/genetics
- Epitopes, B-Lymphocyte/immunology
- Humans
- Immunity, Humoral
- Microarray Analysis/methods
- Nucleocapsid/chemistry
- Nucleocapsid/genetics
- Nucleocapsid/immunology
- Peptides/immunology
- SARS-CoV-2/genetics
- SARS-CoV-2/immunology
- Severity of Illness Index
- Spike Glycoprotein, Coronavirus/chemistry
- Spike Glycoprotein, Coronavirus/genetics
- Spike Glycoprotein, Coronavirus/immunology
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Affiliation(s)
| | | | | | - Michael J. Knauer
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | | | | | - Lori Lowes
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Peter Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Elena Evdokimova
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Peter Loppnau
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Pegah Ghiabi
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Taraneh Haijan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | | | - Husam Abdoh
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Benjamin D. Hedley
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Vipin Bhayana
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Claudio M. Martin
- Department of Medicine, Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | - Marat Slessarev
- Department of Medicine, Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
| | | | - Douglas D. Fraser
- Department of Medicine, Western University, London, Ontario, Canada
- London Health Sciences Centre, London, Ontario, Canada
- Department of Paediatrics, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Ian Chin-Yee
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
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20
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Feng M, Li L, Cheng R, Yuan Y, Dong Y, Chen M, Guo R, Yao M, Xu Y, Zhou Y, Wu J, Ding XS, Zhou X, Tao X. Development of a Mini-Replicon-Based Reverse-Genetics System for Rice Stripe Tenuivirus. J Virol 2021; 95:e0058921. [PMID: 33952642 PMCID: PMC8223943 DOI: 10.1128/jvi.00589-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 04/26/2021] [Indexed: 01/27/2023] Open
Abstract
Negative-stranded RNA (NSR) viruses include both animal- and plant-infecting viruses that often cause serious diseases in humans and livestock and in agronomic crops. Rice stripe tenuivirus (RSV), a plant NSR virus with four negative-stranded/ambisense RNA segments, is one of the most destructive rice pathogens in many Asian countries. Due to the lack of a reliable reverse-genetics technology, molecular studies of RSV gene functions and its interaction with host plants are severely hampered. To overcome this obstacle, we developed a mini-replicon-based reverse-genetics system for RSV gene functional analysis in Nicotiana benthamiana. We first developed a mini-replicon system expressing an RSV genomic RNA3 enhanced green fluorescent protein (eGFP) reporter [MR3(-)eGFP], a nucleocapsid (NP), and a codon usage-optimized RNA-dependent RNA polymerase (RdRpopt). Using this mini-replicon system, we determined that RSV NP and RdRpopt are indispensable for the eGFP expression from MR3(-)eGFP. The expression of eGFP from MR3(-)eGFP can be significantly enhanced in the presence of four viral suppressors of RNA silencing (VSRs), NSs, and P19-HcPro-γb. In addition, NSvc4, the movement protein of RSV, facilitated eGFP trafficking between cells. We also developed an antigenomic RNA3-based replicon in N. benthamiana. However, we found that the RSV NS3 coding sequence acts as a cis element to regulate viral RNA expression. Finally, we made mini-replicons representing all four RSV genomic RNAs. This is the first mini-replicon-based reverse-genetics system for monocot-infecting tenuivirus. We believe that the mini-replicon system described here will allow studies of the RSV replication, transcription, cell-to-cell movement, and host machinery underpinning RSV infection in plants. IMPORTANCE Plant-infecting segmented negative-stranded RNA (NSR) viruses are grouped into three genera: Orthotospovirus, Tenuivirus, and Emaravirus. Reverse-genetics systems have been established for members of the genera Orthotospovirus and Emaravirus. However, there is still no reverse-genetics system available for Tenuivirus. Rice stripe virus (RSV) is a monocot-infecting tenuivirus with four negative-stranded/ambisense RNA segments. It is one of the most destructive rice pathogens and causes significant damage to the rice industry in Asian countries. Due to the lack of a reliable reverse-genetics system, molecular characterizations of RSV gene functions and the host machinery underpinning RSV infection in plants are extremely difficult. To overcome this obstacle, we developed a mini-replicon-based reverse-genetics system for RSV in Nicotiana benthamiana. This is the first mini-replicon-based reverse-genetics system for tenuivirus. We consider that this system will provide researchers a new working platform to elucidate the molecular mechanisms dictating segmented tenuivirus infections in plants.
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Affiliation(s)
- Mingfeng Feng
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Luyao Li
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Ruixiang Cheng
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Yulong Yuan
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Yongxin Dong
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Minglong Chen
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Rong Guo
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Min Yao
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Yi Xu
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Yijun Zhou
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, Nanjing, People’s Republic of China
| | - Jianxiang Wu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People’s Republic of China
| | - Xin Shun Ding
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People’s Republic of China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People’s Republic of China
| | - Xiaorong Tao
- Key Laboratory of Plant Immunity, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, People’s Republic of China
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21
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You HL, Lin MC, Lee CH. Comparison of the Roche cobas 6800 SARS-CoV-2 test and the Taiwan CDC protocol for the molecular diagnosis of COVID-19. Biomed J 2020; 44:101-104. [PMID: 33736952 PMCID: PMC7771907 DOI: 10.1016/j.bj.2020.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 12/16/2020] [Accepted: 12/24/2020] [Indexed: 11/18/2022] Open
Abstract
The current coronavirus disease 2019 (COVID-19) pandemic has caused significant challenges throughout the world and a rapid, reliable diagnostic test is in high demand. Real-time reverse transcription polymerase chain reaction (RT-PCR) was one of the most quickly established methods of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection and is considered to be the gold standard. In this report, we share our experience of using two different testing platforms: the cobas 6800 SARS-CoV-2 test, an automated system that was recently granted Emergency Use Authorization by the FDA, and a laboratory-developed test based on the protocol from the Taiwan Centers for Disease Control (CDC). There was an overall 96.2% agreement between the two platforms. However, the positive agreement between the two platforms was only 80.0%. We found 3 instances of discordance between the two systems and this emphasized the need for timely diagnosis with a reliable testing platform.
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Affiliation(s)
- Huey-Ling You
- Department of Laboratory Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Department of Medical Laboratory Sciences and Biotechnology, Fooyin University, Kaohsiung, Taiwan
| | - Meng-Chih Lin
- Division of Chest Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chen-Hsiang Lee
- Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
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22
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Iserman C, Roden CA, Boerneke MA, Sealfon RSG, McLaughlin GA, Jungreis I, Fritch EJ, Hou YJ, Ekena J, Weidmann CA, Theesfeld CL, Kellis M, Troyanskaya OG, Baric RS, Sheahan TP, Weeks KM, Gladfelter AS. Genomic RNA Elements Drive Phase Separation of the SARS-CoV-2 Nucleocapsid. Mol Cell 2020; 80:1078-1091.e6. [PMID: 33290746 PMCID: PMC7691212 DOI: 10.1016/j.molcel.2020.11.041] [Citation(s) in RCA: 203] [Impact Index Per Article: 50.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/28/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
We report that the SARS-CoV-2 nucleocapsid protein (N-protein) undergoes liquid-liquid phase separation (LLPS) with viral RNA. N-protein condenses with specific RNA genomic elements under physiological buffer conditions and condensation is enhanced at human body temperatures (33°C and 37°C) and reduced at room temperature (22°C). RNA sequence and structure in specific genomic regions regulate N-protein condensation while other genomic regions promote condensate dissolution, potentially preventing aggregation of the large genome. At low concentrations, N-protein preferentially crosslinks to specific regions characterized by single-stranded RNA flanked by structured elements and these features specify the location, number, and strength of N-protein binding sites (valency). Liquid-like N-protein condensates form in mammalian cells in a concentration-dependent manner and can be altered by small molecules. Condensation of N-protein is RNA sequence and structure specific, sensitive to human body temperature, and manipulatable with small molecules, and therefore presents a screenable process for identifying antiviral compounds effective against SARS-CoV-2.
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Affiliation(s)
- Christiane Iserman
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Christine A Roden
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mark A Boerneke
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Grace A McLaughlin
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Irwin Jungreis
- MIT Computer Science and Artificial Intelligence Laboratory, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ethan J Fritch
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yixuan J Hou
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Joanne Ekena
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Chase A Weidmann
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Chandra L Theesfeld
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Manolis Kellis
- MIT Computer Science and Artificial Intelligence Laboratory, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Olga G Troyanskaya
- Center for Computational Biology, Flatiron Institute, New York, NY, USA; Department of Computer Science, Princeton University, Princeton, NJ, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Ralph S Baric
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Timothy P Sheahan
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kevin M Weeks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Amy S Gladfelter
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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23
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Gutsche I, le Mercier P, Kolakofsky D. A paramyxovirus-like model for Ebola virus bipartite promoters. PLoS Pathog 2020; 16:e1008972. [PMID: 33152032 PMCID: PMC7643936 DOI: 10.1371/journal.ppat.1008972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Paramyxo- and filovirus nucleocapsids (NCs) have bipartite promoters at their 3′ ends to initiate RNA synthesis. The 2 elements, promoter element 1 (PE1) and promoter element 2 (PE2), are separated by a spacer region that must be exactly a multiple of 6 nucleotides (nt) long. Paramyxovirus NCs have 13 nucleoprotein (NP) subunits/turn, such that PE1 and PE2 are juxtaposed on the same face of the NC helix, for concerted recognition by the viral polymerase. Ebola virus (EBOV) NCs, in contrast, have 25 to 28 subunits/turn, meaning that PE1 and PE2 cannot be juxtaposed. However, there is evidence that the number of subunits/turn at the 3′ end of the EBOV NC is variable. We propose a paramyxovirus-like model for EBOV explaining why there are 8 contiguous copies of the PE2 repeat when 3 are sufficient, why expanding this run to 13 further improves minigenome performance, and why there is a limit to the number of hexa-nt that can be inserted in the spacer region.
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Affiliation(s)
- Irina Gutsche
- Institut de Biologie Structurale, Univ Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
- * E-mail: (IG); (DK)
| | - Philippe le Mercier
- Swiss-Prot Group, Swiss Institute of Bioinformatics, Centre Médicale Universitaire, Geneva, Switzerland
| | - Daniel Kolakofsky
- Department of Microbiology and Molecular Medicine, University of Geneva Medical School, Geneva, Switzerland
- * E-mail: (IG); (DK)
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24
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Monette A, Mouland AJ. Zinc and Copper Ions Differentially Regulate Prion-Like Phase Separation Dynamics of Pan-Virus Nucleocapsid Biomolecular Condensates. Viruses 2020; 12:E1179. [PMID: 33081049 PMCID: PMC7589941 DOI: 10.3390/v12101179] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/05/2020] [Accepted: 10/12/2020] [Indexed: 02/08/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) is a rapidly growing research focus due to numerous demonstrations that many cellular proteins phase-separate to form biomolecular condensates (BMCs) that nucleate membraneless organelles (MLOs). A growing repertoire of mechanisms supporting BMC formation, composition, dynamics, and functions are becoming elucidated. BMCs are now appreciated as required for several steps of gene regulation, while their deregulation promotes pathological aggregates, such as stress granules (SGs) and insoluble irreversible plaques that are hallmarks of neurodegenerative diseases. Treatment of BMC-related diseases will greatly benefit from identification of therapeutics preventing pathological aggregates while sparing BMCs required for cellular functions. Numerous viruses that block SG assembly also utilize or engineer BMCs for their replication. While BMC formation first depends on prion-like disordered protein domains (PrLDs), metal ion-controlled RNA-binding domains (RBDs) also orchestrate their formation. Virus replication and viral genomic RNA (vRNA) packaging dynamics involving nucleocapsid (NC) proteins and their orthologs rely on Zinc (Zn) availability, while virus morphology and infectivity are negatively influenced by excess Copper (Cu). While virus infections modify physiological metal homeostasis towards an increased copper to zinc ratio (Cu/Zn), how and why they do this remains elusive. Following our recent finding that pan-retroviruses employ Zn for NC-mediated LLPS for virus assembly, we present a pan-virus bioinformatics and literature meta-analysis study identifying metal-based mechanisms linking virus-induced BMCs to neurodegenerative disease processes. We discover that conserved degree and placement of PrLDs juxtaposing metal-regulated RBDs are associated with disease-causing prion-like proteins and are common features of viral proteins responsible for virus capsid assembly and structure. Virus infections both modulate gene expression of metalloproteins and interfere with metal homeostasis, representing an additional virus strategy impeding physiological and cellular antiviral responses. Our analyses reveal that metal-coordinated virus NC protein PrLDs initiate LLPS that nucleate pan-virus assembly and contribute to their persistence as cell-free infectious aerosol droplets. Virus aerosol droplets and insoluble neurological disease aggregates should be eliminated by physiological or environmental metals that outcompete PrLD-bound metals. While environmental metals can control virus spreading via aerosol droplets, therapeutic interference with metals or metalloproteins represent additional attractive avenues against pan-virus infection and virus-exacerbated neurological diseases.
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Affiliation(s)
- Anne Monette
- Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada
| | - Andrew J. Mouland
- Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada
- Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada
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25
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Abstract
Negative strand RNA viruses (NSVs) include many important human pathogens, such as influenza virus, Ebola virus, and rabies virus. One of the unique characteristics that NSVs share is the assembly of the nucleocapsid and its role in viral RNA synthesis. In NSVs, the single strand RNA genome is encapsidated in the linear nucleocapsid throughout the viral replication cycle. Subunits of the nucleocapsid protein are parallelly aligned along the RNA genome that is sandwiched between two domains composed of conserved helix motifs. The viral RNA-dependent-RNA polymerase (vRdRp) must recognize the protein-RNA complex of the nucleocapsid and unveil the protected genomic RNA in order to initiate viral RNA synthesis. In addition, vRdRp must continuously translocate along the protein-RNA complex during elongation in viral RNA synthesis. This unique mechanism of viral RNA synthesis suggests that the nucleocapsid may play a regulatory role during NSV replication.
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Affiliation(s)
- Ming Luo
- Department of Chemistry, Georgia State University, Atlanta, GA 30302, USA; (J.R.T.); (S.A.M.)
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Wee SK, Sivalingam SP, Yap EPH. Rapid Direct Nucleic Acid Amplification Test without RNA Extraction for SARS-CoV-2 Using a Portable PCR Thermocycler. Genes (Basel) 2020; 11:E664. [PMID: 32570810 PMCID: PMC7349311 DOI: 10.3390/genes11060664] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/02/2020] [Accepted: 06/16/2020] [Indexed: 12/20/2022] Open
Abstract
There is an ongoing worldwide coronavirus disease 2019 (Covid-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). At present, confirmatory diagnosis is by reverse transcription polymerase chain reaction (RT-PCR), typically taking several hours and requiring a molecular laboratory to perform. There is an urgent need for rapid, simplified, and cost-effective detection methods. We have developed and analytically validated a protocol for direct rapid extraction-free PCR (DIRECT-PCR) detection of SARS-CoV-2 without the need for nucleic acid purification. As few as six RNA copies per reaction of viral nucleocapsid (N) gene from respiratory samples such as sputum and nasal exudate can be detected directly using our one-step inhibitor-resistant assay. The performance of this assay was validated on a commercially available portable PCR thermocycler. Viral lysis, reverse transcription, amplification, and detection are achieved in a single-tube homogeneous reaction within 36 min. This minimizes hands-on time, reduces turnaround-time for sample-to-result, and obviates the need for RNA purification reagents. It could enable wider use of Covid-19 testing for diagnosis, screening, and research in countries and regions where laboratory capabilities are limiting.
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Affiliation(s)
| | | | - Eric Peng Huat Yap
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore; (S.K.W.); (S.P.S.)
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Liu R, Han H, Liu F, Lv Z, Wu K, Liu Y, Feng Y, Zhu C. Positive rate of RT-PCR detection of SARS-CoV-2 infection in 4880 cases from one hospital in Wuhan, China, from Jan to Feb 2020. Clin Chim Acta 2020; 505:172-175. [PMID: 32156607 PMCID: PMC7094385 DOI: 10.1016/j.cca.2020.03.009] [Citation(s) in RCA: 363] [Impact Index Per Article: 90.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 03/06/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND There's an outbreak of a novel coronavirus (SARS-CoV-2) infection since December 2019, first in China, and currently with more than 80 thousand confirmed infection globally in 29 countries till March 2, 2020. Identification, isolation and caring for patients early are essential to limit human-to-human transmission including reducing secondary infections among close contacts and health care workers, preventing transmission amplification events. The RT-PCR detection of viral nucleic acid test (NAT) was one of the most quickly established laboratory diagnosis method in a novel viral pandemic, just as in this COVID-19 outbreak. METHODS 4880 cases that had respiratory infection symptoms or close contact with COVID-19 patients in hospital in Wuhan, China, were tested for SARS-CoV-2 infection by use of quantitative RT-PCR (qRT-PCR) on samples from the respiratory tract. Positive rates were calculated in groups divided by genders or ages. RESULTS The positive rate was about 38% for the total 4880 specimens. Male and older population had a significant higher positive rates. However, 57% was positive among the specimens from the Fever Clinics. Binary logistic regression analysis showed that age, not gender, was the risk factor for SARS-CoV-2 infection in fever clinics. CONCLUSIONS Therefore, we concluded that viral NAT played an important role in identifying SARS-CoV-2 infection.
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Affiliation(s)
- Rui Liu
- Dept. of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China
| | - Huan Han
- Dept. of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China
| | - Fang Liu
- Dept. State Key Laboratory of Virology (Wuhan University), College of Life Sciences of Wuhan University, Wuhan 430072, Hubei, China; Dept. Wuhan Institute of Biotechnology, Wuhan 430075, Hubei, China
| | - Zhihua Lv
- Dept. of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China
| | - Kailang Wu
- Dept. State Key Laboratory of Virology (Wuhan University), College of Life Sciences of Wuhan University, Wuhan 430072, Hubei, China
| | - Yingle Liu
- Dept. State Key Laboratory of Virology (Wuhan University), College of Life Sciences of Wuhan University, Wuhan 430072, Hubei, China
| | - Yong Feng
- School of Basic Medical Sciences, Wuhan University, Wuhan 430071, Hubei, China.
| | - Chengliang Zhu
- Dept. of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei, China.
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Luo J, Xi J, Gao L, Hu J. Role of Hepatitis B virus capsid phosphorylation in nucleocapsid disassembly and covalently closed circular DNA formation. PLoS Pathog 2020; 16:e1008459. [PMID: 32226051 PMCID: PMC7145273 DOI: 10.1371/journal.ppat.1008459] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 04/09/2020] [Accepted: 03/05/2020] [Indexed: 12/16/2022] Open
Abstract
Hepatitis B virus (HBV) delivers a partially double-stranded, relaxed circular (RC) DNA genome in complete virions to the host cell nucleus for conversion to the covalently closed circular (CCC) DNA, which establishes and sustains viral infection. An overlength pregenomic RNA (pgRNA) is then transcribed from CCC DNA and packaged into immature nucleocapsids (NCs) by the viral core (HBc) protein. pgRNA is reverse transcribed to produce RC DNA in mature NCs, which are then enveloped and secreted as complete virions, or delivered to the nucleus to replenish the nuclear CCC DNA pool. RC DNA, whether originating from extracellular virions or intracellular mature NCs, must be released upon NC disassembly (uncoating) for CCC DNA formation. HBc is known to undergo dynamic phosphorylation and dephosphorylation at its C-terminal domain (CTD) to facilitate pgRNA packaging and reverse transcription. Here, two putative phosphorylation sites in the HBc N-terminal domain (NTD), S44 and S49, were targeted for genetic and biochemical analysis to assess their potential roles in viral replication. The NTD mutant that mimics the non-phosphorylated state (N2A) was competent in all steps of viral replication tested from capsid assembly, pgRNA packaging, reverse transcription, to virion secretion, except for a decrease in CCC DNA formation. On the other hand, the phosphor-mimetic mutant N2E showed a defect in the early step of pgRNA packaging but enhanced the late step of mature NC uncoating and consequently, increased CCC DNA formation. N2E also enhanced phosphorylation in CTD and possibly elsewhere in HBc. Furthermore, inhibition of the cyclin-dependent kinase 2 (CDK2), which is packaged into viral capsids, could block CCC DNA formation. These results prompted us to propose a model whereby rephosphorylation of HBc at both NTD and CTD by the packaged CDK2, following CTD dephosphorylation during NC maturation, facilitates uncoating and CCC DNA formation by destabilizing mature NCs.
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Affiliation(s)
- Jun Luo
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Ji Xi
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Lu Gao
- Roche Pharma Research and Early Development, Roche Innovation Center Shanghai, Shanghai, China
| | - Jianming Hu
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
- * E-mail:
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Comas-Garcia M. Packaging of Genomic RNA in Positive-Sense Single-Stranded RNA Viruses: A Complex Story. Viruses 2019; 11:v11030253. [PMID: 30871184 PMCID: PMC6466141 DOI: 10.3390/v11030253] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 02/06/2023] Open
Abstract
The packaging of genomic RNA in positive-sense single-stranded RNA viruses is a key part of the viral infectious cycle, yet this step is not fully understood. Unlike double-stranded DNA and RNA viruses, this process is coupled with nucleocapsid assembly. The specificity of RNA packaging depends on multiple factors: (i) one or more packaging signals, (ii) RNA replication, (iii) translation, (iv) viral factories, and (v) the physical properties of the RNA. The relative contribution of each of these factors to packaging specificity is different for every virus. In vitro and in vivo data show that there are different packaging mechanisms that control selective packaging of the genomic RNA during nucleocapsid assembly. The goals of this article are to explain some of the key experiments that support the contribution of these factors to packaging selectivity and to draw a general scenario that could help us move towards a better understanding of this step of the viral infectious cycle.
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Affiliation(s)
- Mauricio Comas-Garcia
- Research Center for Health Sciences and Biomedicine (CICSaB), Universidad Autónoma de San Luis Potosí (UASLP), Av. Sierra Leona 550 Lomas 2da Seccion, 72810 San Luis Potosi, Mexico.
- Department of Sciences, Universidad Autónoma de San Luis Potosí (UASLP), Av. Chapultepec 1570, Privadas del Pedregal, 78295 San Luis Potosi, Mexico.
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Gordon TB, Hayward JA, Marsh GA, Baker ML, Tachedjian G. Host and Viral Proteins Modulating Ebola and Marburg Virus Egress. Viruses 2019; 11:v11010025. [PMID: 30609802 PMCID: PMC6357148 DOI: 10.3390/v11010025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/21/2018] [Accepted: 01/01/2019] [Indexed: 12/11/2022] Open
Abstract
The filoviruses Ebolavirus and Marburgvirus are among the deadliest viral pathogens known to infect humans, causing emerging diseases with fatality rates of up to 90% during some outbreaks. The replication cycles of these viruses are comprised of numerous complex molecular processes and interactions with their human host, with one key feature being the means by which nascent virions exit host cells to spread to new cells and ultimately to a new host. This review focuses on our current knowledge of filovirus egress and the viral and host factors and processes that are involved. Within the virus, these factors consist of the major matrix protein, viral protein 40 (VP40), which is necessary and sufficient for viral particle release, and nucleocapsid and glycoprotein that interact with VP40 to promote egress. In the host cell, some proteins are hijacked by filoviruses in order to enhance virion budding capacity that include members of the family of E3 ubiquitin ligase and the endosomal sorting complexes required for transport (ESCRT) pathway, while others such as tetherin inhibit viral egress. An understanding of these molecular interactions that modulate viral particle egress provides an important opportunity to identify new targets for the development of antivirals to prevent and treat filovirus infections.
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Affiliation(s)
- Tamsin B Gordon
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
| | - Joshua A Hayward
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
| | - Glenn A Marsh
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
- CSIRO Australian Animal Health Laboratory, Health and Biosecurity Business Unit, Geelong, VIC 3220, Australia.
| | - Michelle L Baker
- CSIRO Australian Animal Health Laboratory, Health and Biosecurity Business Unit, Geelong, VIC 3220, Australia.
| | - Gilda Tachedjian
- Health Security Program, Life Sciences Discipline, Burnet Institute, Melbourne, VIC 3004, Australia.
- Department of Microbiology, Monash University, Clayton, VIC 3168, Australia.
- Department of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne VIC 3010, Australia.
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, VIC 3000, Australia.
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Lunardi M, Darold GM, Amude AM, Headley SA, Sonne L, Yamauchi KCI, Boabaid FM, Alfieri AF, Alfieri AA. Canine distemper virus active infection in order Pilosa, family Myrmecophagidae, species Tamandua tetradactyla. Vet Microbiol 2018; 220:7-11. [PMID: 29885804 DOI: 10.1016/j.vetmic.2018.04.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/20/2018] [Accepted: 04/23/2018] [Indexed: 02/01/2023]
Abstract
Canine distemper virus (CDV) is a highly contagious disease pathogen which causes disease in the domestic dog and species classified in the Canidae, Procyonidae, Mustelidae, Hyaenidae, Ursidae, Viveridae, Felidae, Tayassuidae, and Cercopithecidae families. A combined strategy that involved the direct sequencing of amplicons from genes coding for nucleocapsid, large polymerase, and hemagglutinin proteins of CDV, as well as the pathological findings and the immunohistochemical detection of viral nucleocapsid protein in diverse tissues, confirmed the participation of CDV in the development of a neurological disease in a southern tamandua (Tamandua tetradactyla) from Midwestern Brazil. Phylogenetic analysis based on the hemagglutinin gene sequences revealed that the strain from this study grouped with isolates from the Europe 1/South America 1 lineage. The specific polymorphisms at the SLAM receptor-binding site of the hemagglutinin gene, previously linked to disease emergence in novel hosts, were not detected in this genome. These findings represent the first description of CDV-induced infection in the Tamandua tetradactyla and extend the distribution of this infection to include members of the family Myrmecophagidae, order Pilosa.
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Affiliation(s)
- Michele Lunardi
- Laboratory of Veterinary Microbiology, Universidade de Cuiabá, 3100 Ave Beira Rio, 78065-900, Cuiabá, MT, Brazil.
| | - Gabriela Molinari Darold
- Laboratory of Veterinary Microbiology, Universidade de Cuiabá, 3100 Ave Beira Rio, 78065-900, Cuiabá, MT, Brazil
| | - Alexandre Mendes Amude
- Department of Small Animal Medicine, Veterinary Teaching Hospital, Universidade de Cuiabá, 3100 Ave Beira Rio, 78065-900, Cuiabá, MT, Brazil
| | - Selwyn Arlington Headley
- Laboratory of Animal Pathology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Celso Garcia Cid Road, PR 445 Km 380, 86051-990, Londrina, PR, Brazil
| | - Luciana Sonne
- Department of Veterinary Pathology, Universidade Federal do Rio Grande do Sul, 9090 Ave Bento Gonçalves, 90650-001, Porto Alegre, RS, Brazil
| | - Kelly Cristiane Ito Yamauchi
- Department of Small Animal Medicine, Veterinary Teaching Hospital, Universidade de Cuiabá, 3100 Ave Beira Rio, 78065-900, Cuiabá, MT, Brazil
| | - Fabiana Marques Boabaid
- Laboratory of Veterinary Pathology, Universidade de Cuiabá, 3100 Ave Beira Rio, 78065-900, Cuiaba, MT, Brazil
| | - Alice Fernandes Alfieri
- Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Celso Garcia Cid Road, PR 445 Km 380, 86051-990, Londrina, PR, Brazil
| | - Amauri Alcindo Alfieri
- Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Celso Garcia Cid Road, PR 445 Km 380, 86051-990, Londrina, PR, Brazil
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32
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Thuenemann EC, Lomonossoff GP. Delivering Cargo: Plant-Based Production of Bluetongue Virus Core-Like and Virus-Like Particles Containing Fluorescent Proteins. Methods Mol Biol 2018; 1776:319-334. [PMID: 29869252 DOI: 10.1007/978-1-4939-7808-3_22] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This chapter provides a practical guide to the in planta transient production of bluetongue virus-like particles containing a fluorescent cargo protein. Bluetongue virus (BTV) particles are icosahedral, multishelled entities of a relatively large size. Heterologous expression of the four main structural proteins of BTV results in the assembly of empty virus-like particles which resemble the native virus externally, but are devoid of nucleic acid. The space within the particles is sufficient to allow incorporation of relatively large cargo proteins, such as green fluorescent protein (GFP), by genetic fusion to the structural protein VP3. The method described utilizes the pEAQ vectors for high-level transient expression of such particles in Nicotiana benthamiana.
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Affiliation(s)
- Eva C Thuenemann
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, UK.
| | - George P Lomonossoff
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, UK
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Guo F, Zhao Q, Sheraz M, Cheng J, Qi Y, Su Q, Cuconati A, Wei L, Du Y, Li W, Chang J, Guo JT. HBV core protein allosteric modulators differentially alter cccDNA biosynthesis from de novo infection and intracellular amplification pathways. PLoS Pathog 2017; 13:e1006658. [PMID: 28945802 PMCID: PMC5629035 DOI: 10.1371/journal.ppat.1006658] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 10/05/2017] [Accepted: 09/19/2017] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV) core protein assembles viral pre-genomic (pg) RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs) and sulfamoylbenzamides (SBAs), have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or “empty” capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc) DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B. Persistent HBV infection relies on stable maintenance of a nuclear episomal viral genome called covalently closed circular (ccc) DNA, the sole transcriptional template supporting viral replication. The currently available antiviral therapeutics fail to cure chronic HBV infection due to their failure to eradicate or inactivate cccDNA. In addition to packaging viral pregenomic (pg) RNA and DNA polymerase complex into nucleocapsids for reverse transcriptional DNA replication to take place, HBV core protein also participates in and regulates virion particle assembly, capsid uncoating and cccDNA formation. We report herein an intriguing observation that selected core protein allosteric modulators not only inhibit nucleocapsid assembly, but can also act on assembled, nucleus-bound nucleocapsids to promote their uncoating and consequentially interfere with cccDNA biosynthesis. This finding establishes molecular basis for development of novel core protein targeting antiviral agents with improved efficacy of suppressing cccDNA synthesis and curing chronic HBV infection.
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Affiliation(s)
- Fang Guo
- Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America
| | - Qiong Zhao
- Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America
| | - Muhammad Sheraz
- Microbiology and Immunology graduate program, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Junjun Cheng
- Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America
| | - Yonghe Qi
- National Institute of Biological Sciences, Beijing, China
| | - Qing Su
- Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America
| | - Andrea Cuconati
- Arbutus Biopharma Inc., Doylestown, Pennsylvania, United States of America
| | - Lai Wei
- Hepatology Institute, Peking University People’s Hospital, Beijing, China
| | - Yanming Du
- Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America
| | - Wenhui Li
- National Institute of Biological Sciences, Beijing, China
| | - Jinhong Chang
- Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America
- * E-mail: (JTG); (JC)
| | - Ju-Tao Guo
- Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America
- * E-mail: (JTG); (JC)
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Mangala Prasad V, Klose T, Rossmann MG. Assembly, maturation and three-dimensional helical structure of the teratogenic rubella virus. PLoS Pathog 2017; 13:e1006377. [PMID: 28575072 PMCID: PMC5470745 DOI: 10.1371/journal.ppat.1006377] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 06/14/2017] [Accepted: 04/25/2017] [Indexed: 01/24/2023] Open
Abstract
Viral infections during pregnancy are a significant cause of infant morbidity and mortality. Of these, rubella virus infection is a well-substantiated example that leads to miscarriages or severe fetal defects. However, structural information about the rubella virus has been lacking due to the pleomorphic nature of the virions. Here we report a helical structure of rubella virions using cryo-electron tomography. Sub-tomogram averaging of the surface spikes established the relative positions of the viral glycoproteins, which differed from the earlier icosahedral models of the virus. Tomographic analyses of in vitro assembled nucleocapsids and virions provide a template for viral assembly. Comparisons of immature and mature virions show large rearrangements in the glycoproteins that may be essential for forming the infectious virions. These results present the first known example of a helical membrane-enveloped virus, while also providing a structural basis for its assembly and maturation pathway. Rubella virus (RV) causes serious fetal defects when contracted during pregnancy. Despite its medical importance, due to the irregular shapes and different sizes of the virions, the RV structure has remained unknown. Using cryo-electron tomography, we have determined the RV structure, which shows a unique, helical outer surface. Subsequent local averaging of the RV surface spikes has established the conformations of its immunogenic glycoproteins. In vitro assembly studies on the virus capsid protein have provided insights into the interactions necessary for virus assembly. Comparisons between mature and immature RV show large conformational changes in the virion structure that are essential for virus maturation. These results help to gain a structural understanding of RV pathogenicity, which may also be relevant to other teratogenic viruses.
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Affiliation(s)
- Vidya Mangala Prasad
- Department of Biological Sciences, 240 S. Martin Jischke Drive, Purdue University, West Lafayette, IN, United States of America
| | - Thomas Klose
- Department of Biological Sciences, 240 S. Martin Jischke Drive, Purdue University, West Lafayette, IN, United States of America
| | - Michael G. Rossmann
- Department of Biological Sciences, 240 S. Martin Jischke Drive, Purdue University, West Lafayette, IN, United States of America
- * E-mail:
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York A, Kutluay SB, Errando M, Bieniasz PD. The RNA Binding Specificity of Human APOBEC3 Proteins Resembles That of HIV-1 Nucleocapsid. PLoS Pathog 2016; 12:e1005833. [PMID: 27541140 PMCID: PMC4991800 DOI: 10.1371/journal.ppat.1005833] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 07/29/2016] [Indexed: 12/11/2022] Open
Abstract
The APOBEC3 (A3) cytidine deaminases are antiretroviral proteins, whose targets include human immunodeficiency virus type-1 (HIV-1). Their incorporation into viral particles is critical for antiviral activity and is driven by interactions with the RNA molecules that are packaged into virions. However, it is unclear whether A3 proteins preferentially target RNA molecules that are destined to be packaged and if so, how. Using cross-linking immunoprecipitation sequencing (CLIP-seq), we determined the RNA binding preferences of the A3F, A3G and A3H proteins. We found that A3 proteins bind preferentially to RNA segments with particular properties, both in cells and in virions. Specifically, A3 proteins target RNA sequences that are G-rich and/or A-rich and are not scanned by ribosomes during translation. Comparative analyses of HIV-1 Gag, nucleocapsid (NC) and A3 RNA binding to HIV-1 RNA in cells and virions revealed the striking finding that A3 proteins partially mimic the RNA binding specificity of the HIV-1 NC protein. These findings suggest a model for A3 incorporation into HIV-1 virions in which an NC-like RNA binding specificity is determined by nucleotide composition rather than sequence. This model reconciles the promiscuity of A3 RNA binding that has been observed in previous studies with a presumed advantage that would accompany selective binding to RNAs that are destined to be packaged into virions.
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Affiliation(s)
- Ashley York
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, United States of America
- Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York, United States of America
| | - Sebla B. Kutluay
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, United States of America
| | - Manel Errando
- Department of Physics, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Paul D. Bieniasz
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, United States of America
- Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York, United States of America
- Howard Hughes Medical Institute, Aaron Diamond AIDS Research Center, New York, New York, United States of America
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Hammel M, Amlanjyoti D, Reyes FE, Chen JH, Parpana R, Tang HYH, Larabell CA, Tainer JA, Adhya S. HU multimerization shift controls nucleoid compaction. Sci Adv 2016; 2:e1600650. [PMID: 27482541 PMCID: PMC4966879 DOI: 10.1126/sciadv.1600650] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 06/14/2016] [Indexed: 05/05/2023]
Abstract
Molecular mechanisms controlling functional bacterial chromosome (nucleoid) compaction and organization are surprisingly enigmatic but partly depend on conserved, histone-like proteins HUαα and HUαβ and their interactions that span the nanoscale and mesoscale from protein-DNA complexes to the bacterial chromosome and nucleoid structure. We determined the crystal structures of these chromosome-associated proteins in complex with native duplex DNA. Distinct DNA binding modes of HUαα and HUαβ elucidate fundamental features of bacterial chromosome packing that regulate gene transcription. By combining crystal structures with solution x-ray scattering results, we determined architectures of HU-DNA nucleoproteins in solution under near-physiological conditions. These macromolecular conformations and interactions result in contraction at the cellular level based on in vivo imaging of native unlabeled nucleoid by soft x-ray tomography upon HUβ and ectopic HUα38 expression. Structural characterization of charge-altered HUαα-DNA complexes reveals an HU molecular switch that is suitable for condensing nucleoid and reprogramming noninvasive Escherichia coli into an invasive form. Collective findings suggest that shifts between networking and cooperative and noncooperative DNA-dependent HU multimerization control DNA compaction and supercoiling independently of cellular topoisomerase activity. By integrating x-ray crystal structures, x-ray scattering, mutational tests, and x-ray imaging that span from protein-DNA complexes to the bacterial chromosome and nucleoid structure, we show that defined dynamic HU interaction networks can promote nucleoid reorganization and transcriptional regulation as efficient general microbial mechanisms to help synchronize genetic responses to cell cycle, changing environments, and pathogenesis.
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Affiliation(s)
- Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Corresponding author. (M.H.); (J.A.T.)
| | - Dhar Amlanjyoti
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Francis E. Reyes
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jian-Hua Chen
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
| | - Rochelle Parpana
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Henry Y. H. Tang
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Carolyn A. Larabell
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
| | - John A. Tainer
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
- Corresponding author. (M.H.); (J.A.T.)
| | - Sankar Adhya
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Racine PJ, Chamontin C, de Rocquigny H, Bernacchi S, Paillart JC, Mougel M. Requirements for nucleocapsid-mediated regulation of reverse transcription during the late steps of HIV-1 assembly. Sci Rep 2016; 6:27536. [PMID: 27273064 PMCID: PMC4895152 DOI: 10.1038/srep27536] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 05/13/2016] [Indexed: 12/19/2022] Open
Abstract
HIV-1 is a retrovirus replicating within cells by reverse transcribing its genomic RNA (gRNA) into DNA. Within cells, virus assembly requires the structural Gag proteins with few accessory proteins, notably the viral infectivity factor (Vif) and two copies of gRNA as well as cellular factors to converge to the plasma membrane. In this process, the nucleocapsid (NC) domain of Gag binds to the packaging signal of gRNA which consists of a series of stem-loops (SL1-SL3) ensuring gRNA selection and packaging into virions. Interestingly, mutating NC activates a late-occurring reverse transcription (RT) step in producer cells, leading to the release of DNA-containing HIV-1 particles. In order to decipher the molecular mechanism regulating this late RT, we explored the role of several key partners of NC, such as Vif, gRNA and the cellular cytidine deaminase APOBEC3G that restricts HIV-1 infection by targeting the RT. By studying combinations of deletions of these putative players, we revealed that NC, SL1-SL3 and in lesser extent Vif, but not APOBEC3G, interplay regulates the late RT.
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Affiliation(s)
- Pierre-Jean Racine
- Centre d'études d’agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Célia Chamontin
- Centre d'études d’agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Hugues de Rocquigny
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74 Route du Rhin, 67401, Illkirch Cedex, France
| | - Serena Bernacchi
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084, Strasbourg, France
| | - Jean-Christophe Paillart
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084, Strasbourg, France
| | - Marylène Mougel
- Centre d'études d’agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
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Higgins CM, Chang WL, Khan S, Tang J, Elliott C, Dietzgen RG. Diversity and evolutionary history of lettuce necrotic yellows virus in Australia and New Zealand. Arch Virol 2016; 161:269-77. [PMID: 26526146 DOI: 10.1007/s00705-015-2626-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 09/24/2015] [Indexed: 11/26/2022]
Abstract
Lettuce necrotic yellows virus (LNYV) is the type member of the genus Cytorhabdovirus, family Rhabdoviridae, and causes a severe disease of lettuce (Lactuca sativa L.). This virus has been described as endemic to Australia and New Zealand, with sporadic reports of a similar virus in Europe. Genetic variability studies of plant-infecting rhabdoviruses are scarce. We have extended a previous study on the variability of the LNYV nucleocapsid gene, comparing sequences from isolates sampled from both Australia and New Zealand, as well as analysing symptom expression on Nicotiana glutinosa. Phylogenetic and BEAST analyses confirm separation of LNYV isolates into two subgroups (I and II) and suggest that subgroup I is slightly older than subgroup II. No correlation was observed between isolate subgroup and disease symptoms on N. glutinosa. The origin of LNYV remains unclear; LNYV may have moved between native and weed hosts within Australia or New Zealand before infecting lettuce or may have appeared as a result of at least two incursions, with the first coinciding with the beginning of European agriculture in the region. The apparent extinction of subgroup I in Australia may have been due to less-efficient dispersal than that which has occurred for subgroup II - possibly a consequence of suboptimal interactions with plant and/or insect hosts. Introduction of subgroup II to New Zealand appears to be more recent. More-detailed epidemiological studies using molecular tools are needed to fully understand how LNYV interacts with its hosts and to determine where the virus originated.
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Affiliation(s)
- Colleen M Higgins
- Institute of Applied Ecology, School of Applied Sciences, Auckland University of Technology, Private Bag 92006, Auckland, 1142, New Zealand.
- AUT Roche Diagnostics Laboratory, Auckland University of Technology, Private Bag 92006, Auckland, 1142, New Zealand.
| | - Wee-Leong Chang
- Institute of Applied Ecology, School of Applied Sciences, Auckland University of Technology, Private Bag 92006, Auckland, 1142, New Zealand
| | - Subuhi Khan
- Plant Health and Environment Laboratory, Ministry for Primary Industries, P.O. Box 2095, Auckland, 1140, New Zealand
| | - Joe Tang
- Plant Health and Environment Laboratory, Ministry for Primary Industries, P.O. Box 2095, Auckland, 1140, New Zealand
| | - Carol Elliott
- Plant Health and Environment Laboratory, Ministry for Primary Industries, P.O. Box 2095, Auckland, 1140, New Zealand
| | - Ralf G Dietzgen
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, QLD, 4072, Australia
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Roy A, Stone AL, Shao J, Otero-Colina G, Wei G, Choudhary N, Achor D, Levy L, Nakhla MK, Hartung JS, Schneider WL, Brlansky RH. Identification and Molecular Characterization of Nuclear Citrus leprosis virus, a Member of the Proposed Dichorhavirus Genus Infecting Multiple Citrus Species in Mexico. Phytopathology 2015; 105:564-75. [PMID: 25423071 DOI: 10.1094/phyto-09-14-0245-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Citrus leprosis is one of the most destructive diseases of Citrus spp. and is associated with two unrelated virus groups that produce particles primarily in either the cytoplasm or nucleus of infected plant cells. Symptoms of leprosis, including chlorotic spots surrounded by yellow haloes on leaves and necrotic spots on twigs and fruit, were observed on leprosis-affected mandarin and navel sweet orange trees in the state of Querétaro, Mexico. Serological and molecular assays showed that the cytoplasmic types of Citrus leprosis virus (CiLV-C) often associated with leprosis symptomatic tissues were absent. However, using transmission electron microscopy, bullet-shaped rhabdovirus-like virions were observed in the nuclei and cytoplasm of the citrus leprosis-infected leaf tissues. An analysis of small RNA populations from symptomatic tissue was carried out to determine the genome sequence of the rhabdovirus-like particles observed in the citrus leprosis samples. The complete genome sequence showed that the nuclear type of CiLV (CiLV-N) present in the samples consisted of two negative-sense RNAs: 6,268-nucleotide (nt)-long RNA1 and 5,847-nt-long RNA2, excluding the poly(A) tails. CiLV-N had a genome organization identical to that of Orchid fleck virus (OFV), with the exception of shorter 5' untranslated regions in RNA1 (53 versus 205 nt) and RNA2 (34 versus 182 nt). Phylogenetic trees constructed with the amino acid sequences of the nucleocapsid (N) and glycoproteins (G) and the RNA polymerase (L protein) showed that CiLV-N clusters with OFV. Furthermore, phylogenetic analyses of N protein established CiLV-N as a member of the proposed genus Dichorhavirus. Reverse-transcription polymerase chain reaction primers for the detection of CiLV-N were designed based on the sequence of the N gene and the assay was optimized and tested to detect the presence of CiLV-N in both diseased and symptom-free plants.
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Affiliation(s)
- Avijit Roy
- First, sixth, seventh, and twelfth authors: University of Florida, IFAS, Plant Pathology Department, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred, FL; second and eleventh authors: United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Foreign Disease-Weed Science Research Unit (FDWSRU), Fort Detrick, MD; third and tenth authors: USDA-ARS, Molecular Plant Pathology Laboratory (MPPL), Beltsville, MD; fourth author: Colegio de Postgraduados, Campus Montecillo, Texcoco, Edo. De Mex., CP 56230, México; fifth and ninth authors: USDA-Animal and Plant Health Inspection Service (APHIS)-Plant Protection and Quarantine (PPQ)-Center for Plant Health Science and Technology (CSIRO), Beltsville, MD; and eighth author: USDA-APHIS-PPQ-CPHST, Riverdale, MD
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Alimova A, Wei H, Katz A, Spatz L, Gottlieb P. The ϕ6 cystovirus protein P7 becomes accessible to antibodies in the transcribing nucleocapsid: a probe for viral structural elements. PLoS One 2015; 10:e0122160. [PMID: 25799314 PMCID: PMC4370446 DOI: 10.1371/journal.pone.0122160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 02/15/2015] [Indexed: 01/01/2023] Open
Abstract
Protein P7 is a component of the cystovirus viral polymerase complex. In the unpackaged procapsid, the protein is situated in close proximity to the viral directed RNA polymerase, P2. Cryo-electron microscopy difference maps from the species ϕ6 procapsid have demonstrated that P7 and P2 likely interact prior to viral RNA packaging. The location of P7 in the post-packaged nucleocapsid (NC) remains unknown. P7 may translocate closer to the five-fold axis of a filled procapsid but this has not been directly visualized. We propose that monoclonal antibodies (Mabs) can be selected that serve as probe- reagents for viral assembly and structure. A set of Mabs have been isolated that recognize and bind to the ϕ6 P7. The antibody set contains five unique Mabs, four of which recognize a linear epitope and one which recognizes a conformational epitope. The four unique Mabs that recognize a linear epitope display restricted utilization of Vκ and VH genes. The restricted genetic range among 4 of the 5 antibodies implies that the antibody repertoire is limited. The limitation could be the consequence of a paucity of exposed antigenic sites on the ϕ6 P7 surface. It is further demonstrated that within ϕ6 nucleocapsids that are primed for early-phase transcription, P7 is partially accessible to the Mabs, indicating that the nucleocapsid shell (protein P8) has undergone partial disassembly exposing the protein’s antigenic sites.
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Affiliation(s)
- Alexandra Alimova
- Sophie Davis School of Biomedical Education, City College of New York, New York, NY 10031, United States of America
| | - Hui Wei
- Sophie Davis School of Biomedical Education, City College of New York, New York, NY 10031, United States of America
| | - Al Katz
- Department of Physics, City College of New York, New York, NY 10031, United States of America
| | - Linda Spatz
- Sophie Davis School of Biomedical Education, City College of New York, New York, NY 10031, United States of America
| | - Paul Gottlieb
- Sophie Davis School of Biomedical Education, City College of New York, New York, NY 10031, United States of America
- * E-mail:
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41
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Wang YL, Liou GG, Lin CH, Chen ML, Kuo TM, Tsai KN, Huang CC, Chen YL, Huang LR, Chou YC, Chang C. The inhibitory effect of the hepatitis B virus singly-spliced RNA-encoded p21.5 protein on HBV nucleocapsid formation. PLoS One 2015; 10:e0119625. [PMID: 25785443 PMCID: PMC4364729 DOI: 10.1371/journal.pone.0119625] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 01/20/2015] [Indexed: 12/29/2022] Open
Abstract
Hepatitis B virus (HBV) is the smallest DNA virus and the major cause of acute and chronic hepatitis. The 3.2 kb HBV viral genome generates four major species of unspliced viral transcript as well as several alternatively spliced RNAs. A 2.2 kb singly-spliced RNA is the most abundant spliced RNA and is widely expressed among all HBV genotypes. The expression of the singly-spliced RNA, as well as that of its encoded protein HBSP, is strongly associated with hepatopathology during HBV infection. Here, we report a novel inhibitory role of a p21.5 protein, which is encoded by a 2.2 kb singly-spliced RNA, in the modulation of HBV replication. We show that overexpression of the singly-spliced RNA is able to efficiently inhibit HBV replication. Furthermore, a mutation in the ATG start codon of the precore region completely abolishes the inhibitory effect of the singly-spliced RNA, indicating that a viral protein (p21.5) derived from the singly-spliced RNA is the mediator of the inhibition. Furthermore, p21.5 is able to form a homodimer that interacts with core dimers forming hybrid viral assembly components. Sucrose gradient fractionation revealed that co-expression of p21.5 resulted in a spread distribution pattern of core proteins ranging from low to high sucrose densities. When compared with p22, p21.5 is almost ten times more efficient at destabilizing HBV nucleocapsid assembly in Huh7 cells overexpressing either p21.5 or p22 protein. Moreover, in vivo expression of p21.5 protein by tail vein injection was found to decrease the amount of nucleocapsid in the livers of HBV-expressing BALB/c mice. In conclusion, our study reveals that the HBV 2.2 kb singly-spliced RNA encodes a 21.5 kDa viral protein that significantly interferes with the assembly of nucleocapsids during HBV nucleocapsid formation. These findings provide a possible strategy for elimination of HBV particles inside cells.
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Affiliation(s)
- Yi-Ling Wang
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Gan-Guang Liou
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Chao-Hsiung Lin
- Institute of Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan
| | - Mong-Liang Chen
- Center for Molecular Medicine, China Medical University and Hospital, Taichung, Taiwan
| | - Tzer-Min Kuo
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Kuen-Nan Tsai
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Chien-Choao Huang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Ya-Ling Chen
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Li-Rung Huang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Yu-Chi Chou
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- * E-mail: (CC); (YCC)
| | - Chungming Chang
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
- * E-mail: (CC); (YCC)
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Weber M, Sediri H, Felgenhauer U, Binzen I, Bänfer S, Jacob R, Brunotte L, García-Sastre A, Schmid-Burgk JL, Schmidt T, Hornung V, Kochs G, Schwemmle M, Klenk HD, Weber F. Influenza virus adaptation PB2-627K modulates nucleocapsid inhibition by the pathogen sensor RIG-I. Cell Host Microbe 2015; 17:309-319. [PMID: 25704008 PMCID: PMC4359673 DOI: 10.1016/j.chom.2015.01.005] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/24/2014] [Accepted: 01/05/2015] [Indexed: 12/16/2022]
Abstract
The cytoplasmic RNA helicase RIG-I mediates innate sensing of RNA viruses. The genomes of influenza A virus (FLUAV) are encapsidated by the nucleoprotein and associated with RNA polymerase, posing potential barriers to RIG-I sensing. We show that RIG-I recognizes the 5'-triphosphorylated dsRNA on FLUAV nucleocapsids but that polymorphisms at position 627 of the viral polymerase subunit PB2 modulate RIG-I sensing. Compared to mammalian-adapted PB2-627K, avian FLUAV nucleocapsids possessing PB2-627E are prone to increased RIG-I recognition, and RIG-I-deficiency partially restores PB2-627E virus infection of mammalian cells. Heightened RIG-I sensing of PB2-627E nucleocapsids correlates with previously established lower affinity of 627E-containing PB2 for nucleoprotein and is increased by further nucleocapsid instability. The effect of RIG-I on PB2-627E nucleocapsids is independent of antiviral signaling, suggesting that RIG-I-nucleocapsid binding alone can inhibit infection. These results indicate that RIG-I is a direct avian FLUAV restriction factor and highlight nucleocapsid disruption as an antiviral strategy.
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Affiliation(s)
- Michaela Weber
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Hanna Sediri
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Ulrike Felgenhauer
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Ina Binzen
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Sebastian Bänfer
- Department of Cell Biology and Cell Pathology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Ralf Jacob
- Department of Cell Biology and Cell Pathology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Linda Brunotte
- Institute for Virology, University Medical Center, D-79008 Freiburg, Germany
| | - Adolfo García-Sastre
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jonathan L Schmid-Burgk
- Institute of Molecular Medicine, University Hospital, University of Bonn, D-53127 Bonn, Germany
| | - Tobias Schmidt
- Institute of Molecular Medicine, University Hospital, University of Bonn, D-53127 Bonn, Germany
| | - Veit Hornung
- Institute of Molecular Medicine, University Hospital, University of Bonn, D-53127 Bonn, Germany
| | - Georg Kochs
- Institute for Virology, University Medical Center, D-79008 Freiburg, Germany
| | - Martin Schwemmle
- Institute for Virology, University Medical Center, D-79008 Freiburg, Germany
| | - Hans-Dieter Klenk
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Friedemann Weber
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany.
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Cruz-Jaramillo JL, Ruiz-Medrano R, Rojas-Morales L, López-Buenfil JA, Morales-Galván O, Chavarín-Palacio C, Ramírez-Pool JA, Xoconostle-Cázares B. Characterization of a proposed dichorhavirus associated with the citrus leprosis disease and analysis of the host response. Viruses 2014; 6:2602-22. [PMID: 25004279 PMCID: PMC4113785 DOI: 10.3390/v6072602] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/22/2014] [Accepted: 05/28/2014] [Indexed: 12/23/2022] Open
Abstract
The causal agents of Citrus leprosis are viruses; however, extant diagnostic methods to identify them have failed to detect known viruses in orange, mandarin, lime and bitter orange trees with severe leprosis symptoms in Mexico, an important citrus producer. Using high throughput sequencing, a virus associated with citrus leprosis was identified, belonging to the proposed Dichorhavirus genus. The virus was termed Citrus Necrotic Spot Virus (CNSV) and contains two negative-strand RNA components; virions accumulate in the cytoplasm and are associated with plasmodesmata-channels interconnecting neighboring cells-suggesting a mode of spread within the plant. The present study provides insights into the nature of this pathogen and the corresponding plant response, which is likely similar to other pathogens that do not spread systemically in plants.
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Affiliation(s)
- José Luis Cruz-Jaramillo
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - Roberto Ruiz-Medrano
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - Lourdes Rojas-Morales
- LaNSE, Centro de Investigación y de Estudios Avanzados del IPN Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - José Abel López-Buenfil
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - Oscar Morales-Galván
- Servicio Nacional de Sanidad Inocuidad y Calidad Agroalimentaria, Guillermo Pérez Valenzuela 127, Coyoacán 04100, México D.F., Mexico.
| | - Claudio Chavarín-Palacio
- Servicio Nacional de Sanidad Inocuidad y Calidad Agroalimentaria, Guillermo Pérez Valenzuela 127, Coyoacán 04100, México D.F., Mexico.
| | - José Abrahán Ramírez-Pool
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - Beatriz Xoconostle-Cázares
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
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Stauffer S, Rahman SA, de Marco A, Carlson LA, Glass B, Oberwinkler H, Herold N, Briggs JAG, Müller B, Grünewald K, Kräusslich HG. The nucleocapsid domain of Gag is dispensable for actin incorporation into HIV-1 and for association of viral budding sites with cortical F-actin. J Virol 2014; 88:7893-903. [PMID: 24789788 PMCID: PMC4097806 DOI: 10.1128/jvi.00428-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 04/24/2014] [Indexed: 12/24/2022] Open
Abstract
Actin and actin-binding proteins are incorporated into HIV-1 particles, and F-actin has been suggested to bind the NC domain in HIV-1 Gag. Furthermore, F-actin has been frequently observed in the vicinity of HIV-1 budding sites by cryo-electron tomography (cET). Filamentous structures emanating from viral buds and suggested to correspond to actin filaments have been observed by atomic force microscopy. To determine whether the NC domain of Gag is required for actin association with viral buds and for actin incorporation into HIV-1, we performed comparative analyses of virus-like particles (VLPs) obtained by expression of wild-type HIV-1 Gag or a Gag variant where the entire NC domain had been replaced by a dimerizing leucine zipper [Gag(LZ)]. The latter protein yielded efficient production of VLPs with near-wild-type assembly kinetics and size and exhibited a regular immature Gag lattice. Typical HIV-1 budding sites were detected by using cET in cells expressing either Gag or Gag(LZ), and no difference was observed regarding the association of buds with the F-actin network. Furthermore, actin was equally incorporated into wild-type HIV-1 and Gag- or Gag(LZ)-derived VLPs, with less actin per particle observed than had been reported previously. Incorporation appeared to correlate with the relative intracellular actin concentration, suggesting an uptake of cytosol rather than a specific recruitment of actin. Thus, the NC domain in HIV-1 Gag does not appear to have a role in actin recruitment or actin incorporation into HIV-1 particles. Importance: HIV-1 particles bud from the plasma membrane, which is lined by a network of actin filaments. Actin was found to interact with the nucleocapsid domain of the viral structural protein Gag and is incorporated in significant amounts into HIV-1 particles, suggesting that it may play an active role in virus release. Using electron microscopy techniques, we previously observed bundles of actin filaments near HIV-1 buds, often seemingly in contact with the Gag layer. Here, we show that this spatial association is observed independently of the proposed actin-binding domain of HIV-1. The absence of this domain also did not affect actin incorporation and had a minor effect on the viral assembly rate. Furthermore, actin was not enriched in the virus compared to the average levels in the respective producing cell. Our data argue against a specific recruitment of actin to HIV-1 budding sites by the nucleocapsid domain of Gag.
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Affiliation(s)
- Sarah Stauffer
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Sheikh Abdul Rahman
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Alex de Marco
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany Molecular Medicine Partnership Unit, Heidelberg, Germany
| | - Lars-Anders Carlson
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Bärbel Glass
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Heike Oberwinkler
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Nikolas Herold
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - John A G Briggs
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany Molecular Medicine Partnership Unit, Heidelberg, Germany
| | - Barbara Müller
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Kay Grünewald
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany Molecular Medicine Partnership Unit, Heidelberg, Germany
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Latus J, Tenner-Racz K, Racz P, Kitterer D, Cadar D, Ott G, Alscher MD, Schmidt-Chanasit J, Braun N. Detection of Puumala hantavirus antigen in human intestine during acute hantavirus infection. PLoS One 2014; 9:e98397. [PMID: 24857988 PMCID: PMC4032337 DOI: 10.1371/journal.pone.0098397] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 05/02/2014] [Indexed: 11/24/2022] Open
Abstract
Background Puumala virus (PUUV) is the most important hantavirus species in Central Europe. Nephropathia epidemica (NE), caused by PUUV, is characterized by acute renal injury (AKI) with thrombocytopenia and frequently gastrointestinal symptoms. Methods 456 patients with serologically and clinically confirmed NE were investigated at time of follow-up in a single clinic. The course of the NE was investigated using medical reports. We identified patients who had endoscopy with intestinal biopsy during acute phase of NE. Histopathological, immunohistochemical and molecular analyses of the biopsies were performed. Results Thirteen patients underwent colonoscopy or gastroscopy for abdominal pain, diarrhea, nausea and vomiting during acute phase of NE. Immunohistochemistry (IHC) revealed PUUV nucleocapsid antigen in 11 biopsies from 8 patients; 14 biopsies from 5 patients were negative for PUUV nucleocapsid antigen. IHC localized PUUV nucleocapsid antigen in endothelial cells of capillaries or larger vessels in the lamina propria. Rate of AKI was not higher and severity of AKI was not different in the PUUV-positive compared to the PUUV-negative group. All IHC positive biopsies were positive for PUUV RNA using RT-PCR. Phylogenetic reconstruction revealed clustering of all PUUV strains from this study with viruses previously detected from the South-West of Germany. Long-term outcome was favorable in both groups. Conclusions In patients with NE, PUUV nucleocapsid antigen and PUUV RNA was detected frequently in the intestine. This finding could explain frequent GI-symptoms in NE patients, thus demonstration of a more generalized PUUV infection. The RT-PCR was an effective and sensitive method to detect PUUV RNA in FFPE tissues. Therefore, it can be used as a diagnostic and phylogenetic approach also for archival materials. AKI was not more often present in patients with PUUV-positive IHC. This last finding should be investigated in larger numbers of patients with PUUV infection.
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Affiliation(s)
- Joerg Latus
- Department of Internal Medicine, Division of Nephrology, Robert-Bosch Hospital, Auerbachstrasse 110, Stuttgart, Germany
| | - Klara Tenner-Racz
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemmorrhagic Fever Reference and Research, Bernhard-Nocht-Strasse 74, Hamburg, Germany
| | - Paul Racz
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemmorrhagic Fever Reference and Research, Bernhard-Nocht-Strasse 74, Hamburg, Germany
| | - Daniel Kitterer
- Department of Internal Medicine, Division of Nephrology, Robert-Bosch Hospital, Auerbachstrasse 110, Stuttgart, Germany
- * E-mail:
| | - Daniel Cadar
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemmorrhagic Fever Reference and Research, Bernhard-Nocht-Strasse 74, Hamburg, Germany
| | - German Ott
- Department of Diagnostic Medicine, Division of Pathology, Robert-Bosch Hospital, Auerbachstrasse 110, Stuttgart, Germany
| | - M. Dominik Alscher
- Department of Internal Medicine, Division of Nephrology, Robert-Bosch Hospital, Auerbachstrasse 110, Stuttgart, Germany
| | - Jonas Schmidt-Chanasit
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemmorrhagic Fever Reference and Research, Bernhard-Nocht-Strasse 74, Hamburg, Germany
- German Centre for Infection Research (DZIF), partner site Hamburg-Luebeck-Borstel, Hamburg, Germany
| | - Niko Braun
- Department of Internal Medicine, Division of Nephrology, Robert-Bosch Hospital, Auerbachstrasse 110, Stuttgart, Germany
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Kasempimolporn S, Saengseesom W, Tirawatnapong T, Puempumpanich S, Sitprija V. Genetic Typing of Feline Rabies Virus Isolated in Greater Bangkok, Thailand. Microbiol Immunol 2013; 48:307-11. [PMID: 15107541 DOI: 10.1111/j.1348-0421.2004.tb03511.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To study the molecular epidemiology of rabies virus that is prevalent among cats in greater Bangkok, Thailand, a total of 17 rabies virus isolates from cats were characterized and compared with 120 rabies virus isolates from dogs. Analyses were performed on the genetic polymorphism in the rabies virus nucleoprotein (N) gene. Rabies virus N gene of isolates was amplified by reverse transcriptionpolymerase chain reaction. The diversity of N gene was revealed by the restriction fragment length polymorphism (RFLP) method. The rabies virus isolates from cats could be classified into 5 types, designated as Dd I-Hf I, Dd II-Hf II, Dd III-Hf I, Dd IV-Hf I, and Dd IV-Hf III. Type Dd I-Hf I was encountered more frequently than the others. It was apparent that no less than five rabies virus types presented in the areas of Bangkok. Moreover, all five RFLP patterns were typical of those which had been observed in dogs. Our findings suggest that there had been viral transmission between the dogs and the cats.
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Affiliation(s)
- Songsri Kasempimolporn
- The Queen Saovabha Memorial Institute (WHO Collaborating Center for Research on Rabies), Thai Red Cross Society, Bangkok, Thailand.
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Abstract
Rabies virus Nishigahara strain causes lethal infection in adult mice after intracerebral inoculation. On the other hand, the RC-HL strain, derived from the Nishigahara strain, does not cause lethal infection in adult mice. We previously demonstrated that a chimeric virus, R(G), with the open reading frame of the G gene (G-ORF) from the Nishigahara strain in the background of the RC-HL genome, is virulent. Reversely, in order to demonstrate that the G gene of the RC-HL strain is related to the attenuated phenotype, we established a reverse genetics system of the Nishigahara strain and generated a chimeric virus, Ni(G), with the G-ORF from RC-HL in the background of the Nishigahara genome. Contrary to our prediction, Ni(G) killed adult mice after intracerebral inoculation with neuropathic symptoms like those of Nishigahara strain infection. Therefore, the G-ORF of the RC-HL strain is not the sole determinant of the attenuated phenotype. In additional investigation, we examined other genes, including N, P, M and L genes, and generated chimeric viruses exhaustively. We found that chimeric viruses with a single gene from the RC-HL were not attenuated and that chimeric viruses with the G-ORF and at least one other ORF from the RC-HL were attenuated. In conclusion, attenuation from the Nishigahara to RC-HL strain is multigenic.
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Affiliation(s)
- Kentaro Yamada
- The United Graduate School of Veterinary Sciences, Division of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu, Gifu 501-1193, Japan
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Beperet I, Barrera G, Simón O, Williams T, López-Ferber M, Gasmi L, Herrero S, Caballero P. The sf32 unique gene of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) is a non-essential gene that could be involved in nucleocapsid organization in occlusion-derived virions. PLoS One 2013; 8:e77683. [PMID: 24204916 PMCID: PMC3813766 DOI: 10.1371/journal.pone.0077683] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 09/04/2013] [Indexed: 12/14/2022] Open
Abstract
A recombinant virus lacking the sf32 gene (Sf32null), unique to the Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), was generated by homologous recombination from a bacmid comprising the complete viral genome (Sfbac). Transcriptional analysis revealed that sf32 is an early gene. Occlusion bodies (OBs) of Sf32null contained 62% more genomic DNA than viruses containing the sf32 gene, Sfbac and Sf32null-repair, although Sf32null DNA was three-fold less infective when injected in vivo. Sf32null OBs were 18% larger in diameter and contained 17% more nucleocapsids within ODVs than those of Sfbac. No significant differences were detected in OB pathogenicity (50% lethal concentration), speed-of-kill or budded virus production in vivo. In contrast, the production of OBs/larva was reduced by 39% in insects infected by Sf32null compared to those infected by Sfbac. The SF32 predicted protein sequence showed homology (25% identity, 44% similarity) to two adhesion proteins from Streptococcus pyogenes and a single N-mirystoylation site was predicted. We conclude that SF32 is a non-essential protein that could be involved in nucleocapsid organization during ODV assembly and occlusion, resulting in increased numbers of nucleocapsids within ODVs.
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Affiliation(s)
- Inés Beperet
- Instituto de Agrobiotecnología, CSIC-UPNA-Gobierno de Navarra, Mutilva Baja, Navarra, Spain
| | - Gloria Barrera
- Instituto de Agrobiotecnología, CSIC-UPNA-Gobierno de Navarra, Mutilva Baja, Navarra, Spain
- Corporación Colombiana de Investigación Agropecuaria (CORPOICA), Bogotá, Colombia
| | - Oihane Simón
- Instituto de Agrobiotecnología, CSIC-UPNA-Gobierno de Navarra, Mutilva Baja, Navarra, Spain
| | | | | | - Laila Gasmi
- Department of Genetics, Univesitat de València, Burjassot, Valencia, Spain
| | - Salvador Herrero
- Department of Genetics, Univesitat de València, Burjassot, Valencia, Spain
| | - Primitivo Caballero
- Instituto de Agrobiotecnología, CSIC-UPNA-Gobierno de Navarra, Mutilva Baja, Navarra, Spain
- Departamento de Producción Agraria, Universidad Pública de Navarra, Pamplona, Navarra, Spain
- * E-mail:
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Nour AM, Li Y, Wolenski J, Modis Y. Viral membrane fusion and nucleocapsid delivery into the cytoplasm are distinct events in some flaviviruses. PLoS Pathog 2013; 9:e1003585. [PMID: 24039574 PMCID: PMC3764215 DOI: 10.1371/journal.ppat.1003585] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 07/12/2013] [Indexed: 12/12/2022] Open
Abstract
Flaviviruses deliver their genome into the cell by fusing the viral lipid membrane to an endosomal membrane. The sequence and kinetics of the steps required for nucleocapsid delivery into the cytoplasm remain unclear. Here we dissect the cell entry pathway of virions and virus-like particles from two flaviviruses using single-particle tracking in live cells, a biochemical membrane fusion assay and virus infectivity assays. We show that the virus particles fuse with a small endosomal compartment in which the nucleocapsid remains trapped for several minutes. Endosomal maturation inhibitors inhibit infectivity but not membrane fusion. We propose a flavivirus cell entry mechanism in which the virus particles fuse preferentially with small endosomal carrier vesicles and depend on back-fusion of the vesicles with the late endosomal membrane to deliver the nucleocapsid into the cytoplasm. Virus entry modulates intracellular calcium release and phosphatidylinositol-3-phosphate kinase signaling. Moreover, the broadly cross-reactive therapeutic antibody scFv11 binds to virus-like particles and inhibits fusion. Many viruses package their genetic material into a lipid envelope. In order to deliver their genome into the host-cell cytoplasm, where it can be replicated, viruses must fuse their envelope with a cellular lipid membrane. This fusion event is therefore a critical step in the entry of an enveloped virus into the cell. In this study, we used various cell biological and biochemical approaches to map precisely the cell entry pathway of two major human pathogens from the flavivirus family, yellow fever virus and Japanese encephalitis virus. We discovered that these viruses co-opt cellular phospholipid signaling to promote the fusion of their envelope with the lipid envelope of small compartments inside the host-cell endosomes. The viral genome remains trapped in these compartments for several minutes until the compartments fuse with the surrounding endosomal membrane. It is this second membrane fusion event that delivers the viral genome into the cytoplasm. We also showed that the antibody fragment scFv11 inhibits the fusion of the viral envelope with small lipid compartments, explaining the therapeutic activity of the scFv11 antibody. Our work identifies new vulnerabilities in the entry pathway of flaviviruses, including the formation of small endosomal compartments and two distinct membrane fusion events involving these compartments.
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Affiliation(s)
- Adel M. Nour
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | - Yue Li
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | - Joseph Wolenski
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Yorgo Modis
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
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50
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Catoni M, Lucioli A, Doblas-Ibáñez P, Accotto GP, Vaira AM. From immunity to susceptibility: virus resistance induced in tomato by a silenced transgene is lost as TGS overcomes PTGS. Plant J 2013; 75:941-953. [PMID: 23738576 DOI: 10.1111/tpj.12253] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 05/20/2013] [Accepted: 05/31/2013] [Indexed: 06/02/2023]
Abstract
Tomato line 30.4 was obtained engineering the nucleocapsid (N) gene of tomato spotted wilt virus into plant genome, and immunity to tomato spotted wilt virus infection of its self-pollinated homozygous progeny was observed. Despite the presence of a high amount of transgenic transcripts, transgenic proteins have not been detected, suggesting a mechanism of resistance mediated by RNA. In the present study, we identify post-transcriptional gene silencing as the main mechanism of resistance, which is able to spread systemically through grafting, and show that the line 30.4 resistant plants produce both 24 and 21-22 nt N-gene specific siRNA classes. The transgenic locus in chromosome 4 shows complex multiple insertions of four T-DNA copies in various orientations, all with 3' end deletions in the terminator and part of the N gene. However, for three of them, polyadenylated transcripts are produced, due to flanking tomato genome sequences acting as alternative terminators. Interestingly, starting at the fifth generation after the transformation event, some individual plants show a tomato spotted wilt virus-susceptible phenotype. The change is associated with the disappearance of transgene-specific transcripts and siRNAs, and with hyper-methylation of the transgene, which proceeds gradually through the generations. Once it reaches a critical threshold, the shift from post-transcriptional gene silencing to transcriptional silencing of the transgene eliminates the previously well established virus resistance.
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Affiliation(s)
- Marco Catoni
- Istituto di Virologia Vegetale, Consiglio Nazionale delle Ricerche, Strada delle Cacce 73, 10135, Turin, Italy.
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