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Kawano K, Hashikura Y, Umekita K. Purification Method of Extracellular Vesicles Derived from Human T-Cell Leukemia Virus Type 1-Infected Cells without Virions. Viruses 2024; 16:249. [PMID: 38400025 PMCID: PMC10892183 DOI: 10.3390/v16020249] [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: 11/17/2023] [Revised: 01/19/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024] Open
Abstract
To mediate intercellular communication, cells produce extracellular vesicles (EVs). These EVs transport many biomolecules such as proteins, nucleic acids, and lipids between cells and regulate pathophysiological actions in the recipient cell. However, EVs and virus particles produced from virus-infected cells are of similar size and specific gravity; therefore, the separation and purification of these two particles is often controversial. When analyzing the physiological functions of EVs from virus-infected cells, the presence or absence of virus particle contamination must always be verified. The human T-cell leukemia virus type 1 (HTLV-1)-infected cell line, MT-2, produces EVs and virus particles. Here, we validated a method for purifying EVs from MT-2 cell culture supernatants while avoiding HTLV-1 viral particle contamination. EV fractions were collected using a combination of immunoprecipitation with Tim-4, which binds to phosphatidylserine, and polymer precipitation. The HTLV-1 viral envelope protein, gp46, was not detected in the EV fraction. Proteomic analysis revealed that EV-constituted proteins were predominant in this EV fraction. Furthermore, the EVs were found to contain the HTLV-1 viral genome. The proposed method can purify EVs while avoiding virus particle contamination and is expected to contribute to future research on EVs derived from HTLV-1-infected cells.
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Affiliation(s)
- Katsumi Kawano
- Division of Respirology, Rheumatology, Infectious Diseases and Neurology, Department of Internal Medicine, University of Miyazaki, Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan;
- Clinical Laboratory, University of Miyazaki of Hospital, Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan;
| | - Yuki Hashikura
- Clinical Laboratory, University of Miyazaki of Hospital, Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan;
| | - Kunihiko Umekita
- Division of Respirology, Rheumatology, Infectious Diseases and Neurology, Department of Internal Medicine, University of Miyazaki, Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan;
- Clinical Laboratory, University of Miyazaki of Hospital, Kihara 5200, Kiyotake, Miyazaki 889-1692, Japan;
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2
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Hwang HS, Lo CM, Murphy M, Grudda T, Gallagher N, Luo CH, Robinson ML, Mirza A, Conte M, Conte A, Zhou R, Vergara C, Brooke CB, Pekosz A, Mostafa HH, Manabe YC, Thio CL, Balagopal A. Characterizing SARS-CoV-2 Transcription of Subgenomic and Genomic RNAs During Early Human Infection Using Multiplexed Droplet Digital Polymerase Chain Reaction. J Infect Dis 2023; 227:981-992. [PMID: 36468309 PMCID: PMC10319975 DOI: 10.1093/infdis/jiac472] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 11/20/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission requires understanding SARS-CoV-2 replication dynamics. METHODS We developed a multiplexed droplet digital polymerase chain reaction (ddPCR) assay to quantify SARS-CoV-2 subgenomic RNAs (sgRNAs), which are only produced during active viral replication, and discriminate them from genomic RNAs (gRNAs). We applied the assay to specimens from 144 people with single nasopharyngeal samples and 27 people with >1 sample. Results were compared to quantitative PCR (qPCR) and viral culture. RESULTS sgRNAs were quantifiable across a range of qPCR cycle threshold (Ct) values and correlated with Ct values. The ratio sgRNA:gRNA was stable across a wide range of Ct values, whereas adjusted amounts of N sgRNA to a human housekeeping gene declined with higher Ct values. Adjusted sgRNA and gRNA amounts were quantifiable in culture-negative samples, although levels were significantly lower than in culture-positive samples. Daily testing of 6 persons revealed that sgRNA is concordant with culture results during the first week of infection but may be discordant with culture later in infection. sgRNA:gRNA is constant during infection despite changes in viral culture. CONCLUSIONS Ct values from qPCR correlate with active viral replication. More work is needed to understand why some cultures are negative despite presence of sgRNA.
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Affiliation(s)
- Hyon S Hwang
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Che-Min Lo
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael Murphy
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Tanner Grudda
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Nicholas Gallagher
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Chun Huai Luo
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Matthew L Robinson
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Agha Mirza
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Madison Conte
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Abigail Conte
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Ruifeng Zhou
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Candelaria Vergara
- Department of Microbiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Christopher B Brooke
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Andrew Pekosz
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Heba H Mostafa
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Yukari C Manabe
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Chloe L Thio
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Ashwin Balagopal
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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3
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Zhou X, Du Z, Huang X. A potential long-range RNA-RNA interaction in the HIV-1 RNA. J Biomol Struct Dyn 2023; 41:14968-14976. [PMID: 36863767 DOI: 10.1080/07391102.2023.2184639] [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: 07/03/2022] [Accepted: 02/19/2023] [Indexed: 03/04/2023]
Abstract
It is well-established that viral and cellular mRNAs alike harbour functional long-range intra-molecular RNA-RNA interactions. Despite the biological importance of such interactions, their identification and characterization remain challenging. Here we present a computational method for the identification of certain kinds of long-range intra-molecular RNA-RNA interactions involving the loop nucleotides of a hairpin loop. Using the computational method, we analysed 4272 HIV-1 genomic mRNAs. A potential long-range intra-molecular RNA-RNA interaction within the HIV-1 genomic RNA was identified. The long-range interaction is mediated by a kissing loop structure between two stem-loops of the previously reported SHAPE-based secondary structure of the entire HIV-1 genome. Structural modelling studies were carried out to show that the kissing loop structure not only is sterically feasible, but also contains a conserved RNA structural motif often found in compact RNA pseudoknots. The computational method should be generally applicable to the identification of potential long-range intra-molecular RNA-RNA interactions in any viral or cellular mRNA sequence.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Xia Zhou
- School of Chemical and Biomolecular Sciences, Southern Illinois University at Carbondale, Carbondale, IL, USA
| | - Zhihua Du
- School of Chemical and Biomolecular Sciences, Southern Illinois University at Carbondale, Carbondale, IL, USA
| | - Xiaolan Huang
- School of Computing, Southern Illinois University at Carbondale, Carbondale, IL, USA
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4
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Väisänen E, Jiang M, Laine L, Waris M, Julkunen I, Österlund P. Infectious viruses from transfected SARS-CoV-2 genomic RNA. Front Bioeng Biotechnol 2023; 11:1129111. [PMID: 37064222 PMCID: PMC10098207 DOI: 10.3389/fbioe.2023.1129111] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/22/2023] [Indexed: 04/18/2023] Open
Abstract
SARS-CoV-2 emerged at the end of 2019, and like other novel pathogens causing severe symptoms, WHO recommended heightened biosafety measures for laboratories working with the virus. The positive-stranded genomic RNA of coronaviruses has been known to be infectious since the 1970s, and overall, all experiments with the possibility of SARS-CoV-2 propagation are carried out in higher containment level laboratories. However, as SARS-CoV-2 RNA has been routinely handled in BSL-2 laboratories, the question of the true nature of RNA infectiousness has risen along with discussion of appropriate biosafety measures. Here, we studied the ability of native SARS-CoV-2 genomic RNA to produce infectious viruses when transfected into permissive cells and discussed the biosafety control measures related to these assays. In transfection assays large quantities of genomic vRNA of SARS-CoV-2 was required for a successful production of infectious viruses. However, the quantity of vRNA alone was not the only factor, and especially when the transfected RNA was derived from infected cells, even small amounts of genomic vRNA was enough for an infection. Virus replication was found to start rapidly after transfection, and infectious viruses were detected in the cell culture media at 24 h post-transfection. In addition, silica membrane-based kits were shown to be as good as traditional TRI-reagent based methods in extracting high-quality, 30 kb-long genomic vRNA. Taken together, our data indicates that all transfection experiments with samples containing genomic SARS-CoV-2 RNA should be categorized as a propagative work and the work should be conducted only in a higher containment BSL-3 laboratory.
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Affiliation(s)
- Elina Väisänen
- Expert Microbiology Unit, Department of Health Security, Finnish Institute for Health and Welfare, Helsinki, Finland
- Infection and Immunity Unit, Institute of Biomedicine, University of Turku, Turku, Finland
- *Correspondence: Elina Väisänen,
| | - Miao Jiang
- Expert Microbiology Unit, Department of Health Security, Finnish Institute for Health and Welfare, Helsinki, Finland
- Infection and Immunity Unit, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Larissa Laine
- Expert Microbiology Unit, Department of Health Security, Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Matti Waris
- Infection and Immunity Unit, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Ilkka Julkunen
- Infection and Immunity Unit, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Pamela Österlund
- Expert Microbiology Unit, Department of Health Security, Finnish Institute for Health and Welfare, Helsinki, Finland
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5
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Candresse T, Svanella-Dumas L, Marais A, Depasse F, Faure C, Lefebvre M. Identification of Seven Additional Genome Segments of Grapevine-Associated Jivivirus 1. Viruses 2022; 15:39. [PMID: 36680079 PMCID: PMC9862270 DOI: 10.3390/v15010039] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
Jiviruses are a group of recently described viruses characterized with a tripartite genome and having affinities with Virgaviridae (RNA1 and 2) and Flaviviridae (RNA3). Using a combination of high-throughput sequencing, datamining and RT-PCR approaches, we demonstrate here that in grapevine samples infected by grapevine-associated jivivirus 1 (GaJV-1) up to 7 additional molecules can be consistently detected with conserved 5' and 3' non-coding regions in common with the three previously identified GaJV-1 genomic RNAs. RNA4, RNA5, RNA6, RNA7, RNA8 and RNA10, together with a recombinant RNArec7-8, are all members of a family sharing a previously non recognized conserved protein domain, while RNA9 is part of a distinct family characterized by another conserved motif. Datamining of pecan (Carya illinoinensis) public transcriptomic data allowed the identification of two further jiviviruses and the identification of supplementary genomic RNAs with homologies to those of GaJV-1. Taken together, these results reshape our vision of the divided genome of jiviviruses and raise novel questions about the function(s) of the proteins encoded by jiviviruses supplementary RNAs.
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Affiliation(s)
- Thierry Candresse
- INRAE, UMR BFP, University of Bordeaux, CS20032, CEDEX, 33882 Villenave d’Ornon, France
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6
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Gilmer O, Mailler E, Paillart JC, Mouhand A, Tisné C, Mak J, Smyth RP, Marquet R, Vivet-Boudou V. Structural maturation of the HIV-1 RNA 5' untranslated region by Pr55 Gag and its maturation products. RNA Biol 2022; 19:191-205. [PMID: 35067194 PMCID: PMC8786341 DOI: 10.1080/15476286.2021.2021677] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Maturation of the HIV-1 viral particles shortly after budding is required for infectivity. During this process, the Pr55Gag precursor undergoes a cascade of proteolytic cleavages, and whilst the structural rearrangements of the viral proteins are well understood, the concomitant maturation of the genomic RNA (gRNA) structure is unexplored, despite evidence that it is required for infectivity. To get insight into this process, we systematically analysed the interactions between Pr55Gag or its maturation products (NCp15, NCp9 and NCp7) and the 5ʹ gRNA region and their structural consequences, in vitro. We show that Pr55Gag and its maturation products mostly bind at different RNA sites and with different contributions of their two zinc knuckle domains. Importantly, these proteins have different transient and permanent effects on the RNA structure, the late NCp9 and NCp7 inducing dramatic structural rearrangements. Altogether, our results reveal the distinct contributions of the different Pr55Gag maturation products on the gRNA structural maturation.
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Affiliation(s)
- Orian Gilmer
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, IBMC, Strasbourg, France
| | - Elodie Mailler
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, IBMC, Strasbourg, France
| | - Jean-Christophe Paillart
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, IBMC, Strasbourg, France
| | - Assia Mouhand
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-chimique, Paris, France
| | - Carine Tisné
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-chimique, Paris, France
| | - Johnson Mak
- Institute for Glycomics, Griffith University, Gold Coast, Australia
| | - Redmond P Smyth
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, IBMC, Strasbourg, France
| | - Roland Marquet
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, IBMC, Strasbourg, France
| | - Valérie Vivet-Boudou
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, IBMC, Strasbourg, France
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7
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Chang JY, Gorzelnik KV, Thongchol J, Zhang J. Structural Assembly of Qβ Virion and Its Diverse Forms of Virus-like Particles. Viruses 2022; 14:225. [PMID: 35215818 PMCID: PMC8880383 DOI: 10.3390/v14020225] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 01/18/2022] [Accepted: 01/21/2022] [Indexed: 02/04/2023] Open
Abstract
The coat proteins (CPs) of single-stranded RNA bacteriophages (ssRNA phages) directly assemble around the genomic RNA (gRNA) to form a near-icosahedral capsid with a single maturation protein (Mat) that binds the gRNA and interacts with the retractile pilus during infection of the host. Understanding the assembly of ssRNA phages is essential for their use in biotechnology, such as RNA protection and delivery. Here, we present the complete gRNA model of the ssRNA phage Qβ, revealing that the 3' untranslated region binds to the Mat and the 4127 nucleotides fold domain-by-domain, and is connected through long-range RNA-RNA interactions, such as kissing loops. Thirty-three operator-like RNA stem-loops are located and primarily interact with the asymmetric A/B CP-dimers, suggesting a pathway for the assembly of the virions. Additionally, we have discovered various forms of the virus-like particles (VLPs), including the canonical T = 3 icosahedral, larger T = 4 icosahedral, prolate, oblate forms, and a small prolate form elongated along the 3-fold axis. These particles are all produced during a normal infection, as well as when overexpressing the CPs. When overexpressing the shorter RNA fragments encoding only the CPs, we observed an increased percentage of the smaller VLPs, which may be sufficient to encapsidate a shorter RNA.
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Affiliation(s)
| | | | | | - Junjie Zhang
- Center for Phage Technology, Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA; (J.-Y.C.); (K.V.G.); (J.T.)
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8
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Zhang S, Amahong K, Zhang C, Li F, Gao J, Qiu Y, Zhu F. RNA-RNA interactions between SARS-CoV-2 and host benefit viral development and evolution during COVID-19 infection. Brief Bioinform 2022; 23:bbab397. [PMID: 34585235 PMCID: PMC8500159 DOI: 10.1093/bib/bbab397] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [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: 07/13/2021] [Revised: 08/11/2021] [Accepted: 08/30/2021] [Indexed: 12/14/2022] Open
Abstract
Some studies reported that genomic RNA of SARS-CoV-2 can absorb a few host miRNAs that regulate immune-related genes and then deprive their function. In this perspective, we conjecture that the absorption of the SARS-CoV-2 genome to host miRNAs is not a coincidence, which may be an indispensable approach leading to viral survival and development in host. In our study, we collected five datasets of miRNAs that were predicted to interact with the genome of SARS-CoV-2. The targets of these miRNAs in the five groups were consistently enriched immune-related pathways and virus-infectious diseases. Interestingly, the five datasets shared no one miRNA but their targets shared 168 genes. The signaling pathway enrichment of 168 shared targets implied an unbalanced immune response that the most of interleukin signaling pathways and none of the interferon signaling pathways were significantly different. Protein-protein interaction (PPI) network using the shared targets showed that PPI pairs, including IL6-IL6R, were related to the process of SARS-CoV-2 infection and pathogenesis. In addition, we found that SARS-CoV-2 absorption to host miRNA could benefit two popular mutant strains for more infectivity and pathogenicity. Conclusively, our results suggest that genomic RNA absorption to host miRNAs may be a vital approach by which SARS-CoV-2 disturbs the host immune system and infects host cells.
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Affiliation(s)
- Song Zhang
- College of Pharmaceutical Sciences in Zhejiang University, and the First Affiliated Hospital of Zhejiang University School of Medicine, China
| | | | - Chenyang Zhang
- College of Pharmaceutical Sciences in Zhejiang University, China
| | - Fengcheng Li
- College of Pharmaceutical Sciences in Zhejiang University, China
| | - Jianqing Gao
- College of Pharmaceutical Sciences in Zhejiang University, China
| | - Yunqing Qiu
- First Affiliated Hospital in Zhejiang University, China
| | - Feng Zhu
- College of Pharmaceutical Sciences in Zhejiang University, China
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9
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Durand S, Seigneuret F, Burlaud-Gaillard J, Lemoine R, Tassi MF, Moreau A, Mougel M, Roingeard P, Tauber C, de Rocquigny H. Quantitative analysis of the formation of nucleoprotein complexes between HIV-1 Gag protein and genomic RNA using transmission electron microscopy. J Biol Chem 2022; 298:101500. [PMID: 34929171 PMCID: PMC8760521 DOI: 10.1016/j.jbc.2021.101500] [Citation(s) in RCA: 2] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 12/05/2021] [Indexed: 01/06/2023] Open
Abstract
In HIV, the polyprotein precursor Gag orchestrates the formation of the viral capsid. In the current view of this viral assembly, Gag forms low-order oligomers that bind to the viral genomic RNA triggering the formation of high-ordered ribonucleoprotein complexes. However, this assembly model was established using biochemical or imaging methods that do not describe the cellular location hosting Gag-gRNA complex nor distinguish gRNA packaging in single particles. Here, we studied the intracellular localization of these complexes by electron microscopy and monitored the distances between the two partners by morphometric analysis of gold beads specifically labeling Gag and gRNA. We found that formation of these viral clusters occurred shortly after the nuclear export of the gRNA. During their transport to the plasma membrane, the distance between Gag and gRNA decreases together with an increase of gRNA packaging. Point mutations in the zinc finger patterns of the nucleocapsid domain of Gag caused an increase in the distance between Gag and gRNA as well as a sharp decrease of gRNA packaged into virions. Finally, we show that removal of stem loop 1 of the 5'-untranslated region does not interfere with gRNA packaging, whereas combined with the removal of stem loop 3 is sufficient to decrease but not abolish Gag-gRNA cluster formation and gRNA packaging. In conclusion, this morphometric analysis of Gag-gRNA cluster formation sheds new light on HIV-1 assembly that can be used to describe at nanoscale resolution other viral assembly steps involving RNA or protein-protein interactions.
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Affiliation(s)
- Stéphanie Durand
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Florian Seigneuret
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Julien Burlaud-Gaillard
- Microscopy IBiSA Platform, PPF ASB, University of Tours and CHRU of Tours, Tours Cedex 1, France
| | - Roxane Lemoine
- B Cell Ressources Platform, EA4245 "Transplantation, Immunology and Inflammation", University of Tours, Tours Cedex 1, France
| | - Marc-Florent Tassi
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Alain Moreau
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Marylène Mougel
- Équipe R2D2 Retroviral RNA Dynamics and Delivery, IRIM, CNRS UMR9004, University of Montpellier, Montpellier, France
| | - Philippe Roingeard
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France; Microscopy IBiSA Platform, PPF ASB, University of Tours and CHRU of Tours, Tours Cedex 1, France
| | - Clovis Tauber
- UMR U1253 iBrain, Inserm, University of Tours, Tours Cedex 1, France
| | - Hugues de Rocquigny
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France.
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10
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Tariq M, Kim DM, Kim CM, Bang MS, Lee YM, Seo JW, Kim DY, Yun NR. Viable Severe Acute Respiratory Syndrome Coronavirus 2 Isolates Exhibit Higher Correlation With Rapid Antigen Assays Than Sub genomic RNA or Genomic RNA. Front Microbiol 2021; 12:718497. [PMID: 34867844 PMCID: PMC8633410 DOI: 10.3389/fmicb.2021.718497] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 10/11/2021] [Indexed: 12/23/2022] Open
Abstract
Background: Rapid identification and effective isolation are crucial for curbing the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To meet this requirement, antigen-detection rapid diagnostic tests (Ag-RDTs) are essential. Methods: Between February 2020 and August 2020 we performed a cohort study of patients with confirmed COVID-19. The clinical performance of Ag rapid fluorescence immunoassay (FIA) and Ag Gold was evaluated and compared in parallel with genomic and subgenomic real-time reverse transcription-polymerase chain reaction (rRT-PCR) and cell culture-based assays. Results: In total, 150 samples were tested. Of these, 63 serial samples were obtained from 11 patients with SARS-CoV-2 and 87 from negative controls. Serial respiratory samples were obtained 2 days prior to symptom onset (-2) up to 25 days post-symptom onset. Overall, for rRT-PCR-positive samples (n = 51), the detection sensitivity of Ag rapid FIA and Ag Gold was 74.5% and 53.49%, respectively, with a specificity of 100%; however, for samples with low cycle threshold (Ct) values, Ag rapid FIA and Ag Gold exhibited a sensitivity of 82.61% (Ct ≤ 30, 5.6 log10RNA copies/mL) and 80% (Ct ≤ 25, 6.9 log10RNA copies/mL), respectively. Despite low analytical sensitivity, both Ag-RDTs detected 100% infection in cell culture-positive samples (n = 15) and were highly effective in distinguishing viable samples from those with subgenomic RNA (66.66%). For both Ag-RDTs, all samples that yielded discordant results (rRT-PCR + ve/Ag-RDT -ve) were also negative by culture. Conclusion: The data suggest that Ag-RDTs reliably detect viable SARS-CoV-2; thus, they may serve as an important tool for rapid detection of potentially infectious individuals.
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Affiliation(s)
- Misbah Tariq
- Department of Internal Medicine, Chosun University College of Medicine, Gwangju, South Korea
| | - Dong-Min Kim
- Department of Internal Medicine, Chosun University College of Medicine, Gwangju, South Korea
| | - Choon-Mee Kim
- Premedical Science, Chosun University College of Medicine, Gwangju, South Korea
| | - Mi-Seon Bang
- Department of Internal Medicine, Chosun University College of Medicine, Gwangju, South Korea
| | - You Mi Lee
- Department of Internal Medicine, Chosun University College of Medicine, Gwangju, South Korea
| | - Jun-Won Seo
- Department of Internal Medicine, Chosun University College of Medicine, Gwangju, South Korea
| | - Da Young Kim
- Department of Internal Medicine, Chosun University College of Medicine, Gwangju, South Korea
| | - Na Ra Yun
- Department of Internal Medicine, Chosun University College of Medicine, Gwangju, South Korea
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Ponomareva EP, Ternovoi VA, Mikryukova TP, Protopopova EV, Tupota NL, Loktev VB. [Genetic Variability of Tick-Borne Encephalitis Virus Genome 5'-UTR from Northern Eurasia]. Mol Biol (Mosk) 2021; 55:431-440. [PMID: 34097678 DOI: 10.31857/s0026898421030149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/15/2020] [Indexed: 11/24/2022]
Abstract
This paper reports the analysis of the nucleotide sequences of the 5'-untranslated region (5'-UTR) of tick-borne encephalitis virus (TBEV) genomic RNA isolated from 39 individual taiga ticks collected in several regions of Northern Eurasia. The sequences of 5'-UTRs of the Siberian and Far East TBEV genotypes were 89% and 95% identical to the prototype strains (Zausaev and 205), respectively. The detected nucleotide substitutions were typical for these two TBEV genotypes, which made possible unambiguous identification. Both conservative and variable motifs were detected in the 5'-UTR RNA. The B2, C1, and C2 elements of the Y-shaped 5'-UTR structure and the presumable viral RNA-dependent RNA-polymerase binding site were the most variable. The A2, CS A, CS В elements as well as the start codon were conservative. Interestingly, five substitutions in the 5'-UTR C1 variable element of the TBEVs isolated in different geographical regions were strictly conservative, while 11 different substitutions were detected in this element among the laboratory TBEV variants. A little less that a third of all nucleotide substitutions were mapped outside the main elements of the Y-shaped structure. In general, nucleotide substitutions were localized to stem structures, not being found in the hairpin regions of the TBEV 5'-UTR. The results indicated significant variability of the genomic RNA 5'-UTR in the TBEV laboratory strains and field isolates obtained from different geographical regions. It has been suggested that genetic variability of 5'-UTR is characteristic of the TBEV genome 5'-UTR organization and may serve as a structural basis for virus efficient replication in various avian, mammalian, and ixodic tick cells.
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Affiliation(s)
- E P Ponomareva
- Vector State Scientific Center for Virology and Biotechnology, Koltsovo, Novosibirsk oblast, 630559 Russia.,
| | - V A Ternovoi
- Vector State Scientific Center for Virology and Biotechnology, Koltsovo, Novosibirsk oblast, 630559 Russia
| | - T P Mikryukova
- Vector State Scientific Center for Virology and Biotechnology, Koltsovo, Novosibirsk oblast, 630559 Russia
| | - E V Protopopova
- Vector State Scientific Center for Virology and Biotechnology, Koltsovo, Novosibirsk oblast, 630559 Russia
| | - N L Tupota
- Vector State Scientific Center for Virology and Biotechnology, Koltsovo, Novosibirsk oblast, 630559 Russia
| | - V B Loktev
- Vector State Scientific Center for Virology and Biotechnology, Koltsovo, Novosibirsk oblast, 630559 Russia
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12
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Abstract
DEAD box RNA helicases regulate diverse facets of RNA biology. Proteins of this family carry out essential cellular functions, and emerging literature is revealing additional roles in immune defense. Using RNA interference screening, we identified an evolutionarily conserved antiviral role for the helicase DDX56 against the alphavirus Sindbis virus (SINV), a mosquito-transmitted pathogen that infects humans. Depletion of DDX56 enhanced infection in Drosophila and human cells. Furthermore, we found that DDX56 also controls the emerging alphavirus chikungunya virus (CHIKV) through an interferon-independent mechanism. Using cross-linking immunoprecipitation (CLIP-Seq), we identified a predicted stem-loop on the viral genomic RNA bound by DDX56. Mechanistically, we found that DDX56 levels increase in the cytoplasm during CHIKV infection. In the cytoplasm, DDX56 impacts the earliest step in the viral replication cycle by binding and destabilizing the incoming viral genomic RNA, thereby attenuating infection. Thus, DDX56 is a conserved antiviral RNA binding protein that controls alphavirus infection.IMPORTANCE Arthropod-borne viruses are diverse pathogens and include the emerging virus chikungunya virus, which is associated with human disease. Through genetic screening, we found that the conserved RNA binding protein DDX56 is antiviral against chikungunya virus in insects and humans. DDX56 relocalizes from the nucleus to the cytoplasm, where it binds to a stem-loop in the viral genome and destabilizes incoming genomes. Thus, DDX56 is an evolutionarily conserved antiviral factor that controls alphavirus infection.
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Dubois N, Khoo KK, Ghossein S, Seissler T, Wolff P, McKinstry WJ, Mak J, Paillart JC, Marquet R, Bernacchi S. The C-terminal p6 domain of the HIV-1 Pr55 Gag precursor is required for specific binding to the genomic RNA. RNA Biol 2018; 15:923-936. [PMID: 29954247 DOI: 10.1080/15476286.2018.1481696] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The Pr55Gag precursor specifically selects the HIV-1 genomic RNA (gRNA) from a large excess of cellular and partially or fully spliced viral RNAs and drives the virus assembly at the plasma membrane. During these processes, the NC domain of Pr55Gag interacts with the gRNA, while its C-terminal p6 domain binds cellular and viral factors and orchestrates viral particle release. Gag∆p6 is a truncated form of Pr55Gag lacking the p6 domain usually used as a default surrogate for wild type Pr55Gag for in vitro analysis. With recent advance in production of full-length recombinant Pr55Gag, here, we tested whether the p6 domain also contributes to the RNA binding specificity of Pr55Gag by systematically comparing binding of Pr55Gag and Gag∆p6 to a panel of viral and cellular RNAs. Unexpectedly, our fluorescence data reveal that the p6 domain is absolutely required for specific binding of Pr55Gag to the HIV-1 gRNA. Its deletion resulted not only in a decreased affinity for gRNA, but also in an increased affinity for spliced viral and cellular RNAs. In contrast Gag∆p6 displayed a similar affinity for all tested RNAs. Removal of the C-terminal His-tag from Pr55Gag and Gag∆p6 uniformly increased the Kd values of the RNA-protein complexes by ~ 2.5 fold but did not affect the binding specificities of these proteins. Altogether, our results demonstrate a novel role of the p6 domain in the specificity of Pr55Gag-RNA interactions, and strongly suggest that the p6 domain contributes to the discrimination of HIV-1 gRNA from cellular and spliced viral mRNAs, which is necessary for its selective encapsidation.
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Affiliation(s)
- Noé Dubois
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | - Keith K Khoo
- b School of Medicine , Deakin University , Geelong , Australia.,c CSIRO Manufacturing , Parkville , Australia
| | - Shannon Ghossein
- b School of Medicine , Deakin University , Geelong , Australia.,c CSIRO Manufacturing , Parkville , Australia
| | - Tanja Seissler
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | - Philippe Wolff
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France.,d Plateforme protéomique Strasbourg-Esplanade, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | | | - Johnson Mak
- b School of Medicine , Deakin University , Geelong , Australia.,e Institute for Glycomics, Griffith University , Southport , Australia
| | - Jean-Christophe Paillart
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | - Roland Marquet
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | - Serena Bernacchi
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
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14
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Arkhipenko MV, Nikitin NA, Donchenko EK, Karpova OV, Atabekov JG. Translational Cross-Activation of the Encapsidated RNA of Potexviruses. Acta Naturae 2017; 9:52-57. [PMID: 29340217 PMCID: PMC5762828] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Indexed: 10/29/2022] Open
Abstract
We had shown the genomic RNA of potexviruses potato virus X and the alternanthera mosaic virus to be inaccessible in vitro to ribosomes while in intact virion form, but the RNAs can be translationally activated following the binding of movement protein 1 (MP1) to virus particles. Here, we present the results of the follow-up study targeting two more potexvirus species - the Narcissus mosaic virus and the Potato aucuba mosaic virus. We found encapsidated potexviral RNA to share common translational features in vitro and the MP1 to be potent over homological virions of its "own" species and over heterological virions of other species, as well exhibiting selective specificity. Reciprocal cross-activation is observed among viral species phylogenetically either close or distant. There is direct evidence that MP1 binding to the end of the virion is necessary, but not sufficient, for translational activation of encapsidated RNA.
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Affiliation(s)
- M. V. Arkhipenko
- Biology Department, Lomonosov Moscow State University, 1 bld. 12 Leninskie gory, Moscow, 119234 , Russia
| | - N. A. Nikitin
- Biology Department, Lomonosov Moscow State University, 1 bld. 12 Leninskie gory, Moscow, 119234 , Russia
| | - E. K. Donchenko
- Biology Department, Lomonosov Moscow State University, 1 bld. 12 Leninskie gory, Moscow, 119234 , Russia
| | - O. V. Karpova
- Biology Department, Lomonosov Moscow State University, 1 bld. 12 Leninskie gory, Moscow, 119234 , Russia
| | - J. G. Atabekov
- Biology Department, Lomonosov Moscow State University, 1 bld. 12 Leninskie gory, Moscow, 119234 , Russia
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Gorzelnik KV, Cui Z, Reed CA, Jakana J, Young R, Zhang J. Asymmetric cryo-EM structure of the canonical Allolevivirus Qβ reveals a single maturation protein and the genomic ssRNA in situ. Proc Natl Acad Sci U S A 2016; 113:11519-11524. [PMID: 27671640 PMCID: PMC5068298 DOI: 10.1073/pnas.1609482113] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [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: 11/18/2022] Open
Abstract
Single-stranded (ss) RNA viruses infect all domains of life. To date, for most ssRNA virions, only the structures of the capsids and their associated protein components have been resolved to high resolution. Qβ, an ssRNA phage specific for the conjugative F-pilus, has a T = 3 icosahedral lattice of coat proteins assembled around its 4,217 nucleotides of genomic RNA (gRNA). In the mature virion, the maturation protein, A2, binds to the gRNA and is required for adsorption to the F-pilus. Here, we report the cryo-electron microscopy (cryo-EM) structures of Qβ with and without symmetry applied. The icosahedral structure, at 3.7-Å resolution, resolves loops not previously seen in the published X-ray structure, whereas the asymmetric structure, at 7-Å resolution, reveals A2 and the gRNA. A2 contains a bundle of α-helices and replaces one dimer of coat proteins at a twofold axis. The helix bundle binds gRNA, causing denser packing of RNA in its proximity, which asymmetrically expands the surrounding coat protein shell to potentially facilitate RNA release during infection. We observe a fixed pattern of gRNA organization among all viral particles, with the major and minor grooves of RNA helices clearly visible. A single layer of RNA directly contacts every copy of the coat protein, with one-third of the interactions occurring at operator-like RNA hairpins. These RNA-coat interactions stabilize the tertiary structure of gRNA within the virion, which could further provide a roadmap for capsid assembly.
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Affiliation(s)
- Karl V Gorzelnik
- Center for Phage Technology, Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Zhicheng Cui
- Center for Phage Technology, Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Catrina A Reed
- Center for Phage Technology, Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Joanita Jakana
- National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Ry Young
- Center for Phage Technology, Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843
| | - Junjie Zhang
- Center for Phage Technology, Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843;
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16
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Ali LM, Rizvi TA, Mustafa F. Cross- and Co-Packaging of Retroviral RNAs and Their Consequences. Viruses 2016; 8:E276. [PMID: 27727192 DOI: 10.3390/v8100276] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/03/2016] [Accepted: 10/03/2016] [Indexed: 12/23/2022] Open
Abstract
Retroviruses belong to the family Retroviridae and are ribonucleoprotein (RNP) particles that contain a dimeric RNA genome. Retroviral particle assembly is a complex process, and how the virus is able to recognize and specifically capture the genomic RNA (gRNA) among millions of other cellular and spliced retroviral RNAs has been the subject of extensive investigation over the last two decades. The specificity towards RNA packaging requires higher order interactions of the retroviral gRNA with the structural Gag proteins. Moreover, several retroviruses have been shown to have the ability to cross-/co-package gRNA from other retroviruses, despite little sequence homology. This review will compare the determinants of gRNA encapsidation among different retroviruses, followed by an examination of our current understanding of the interaction between diverse viral genomes and heterologous proteins, leading to their cross-/co-packaging. Retroviruses are well-known serious animal and human pathogens, and such a cross-/co-packaging phenomenon could result in the generation of novel viral variants with unknown pathogenic potential. At the same time, however, an enhanced understanding of the molecular mechanisms involved in these specific interactions makes retroviruses an attractive target for anti-viral drugs, vaccines, and vectors for human gene therapy.
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17
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Abstract
Like other retroviruses, human immunodeficiency virus type 1 (HIV-1) selectively packages genomic RNA (gRNA) during virus assembly. However, in the absence of the gRNA, cellular messenger RNAs (mRNAs) are packaged. While the gRNA is selected because of its cis-acting packaging signal, the mechanism of this selection is not understood. The affinity of Gag (the viral structural protein) for cellular RNAs at physiological ionic strength is not much higher than that for the gRNA. However, binding to the gRNA is more salt-resistant, implying that it has a higher non-electrostatic component. We have previously studied the spacer 1 (SP1) region of Gag and showed that it can undergo a concentration-dependent conformational transition. We proposed that this transition represents the first step in assembly, i.e., the conversion of Gag to an assembly-ready state. To explain selective packaging of gRNA, we suggest here that binding of Gag to gRNA, with its high non-electrostatic component, triggers this conversion more readily than binding to other RNAs; thus we predict that a Gag-gRNA complex will nucleate particle assembly more efficiently than other Gag-RNA complexes. New data shows that among cellular mRNAs, those with long 3'-untranslated regions (UTR) are selectively packaged. It seems plausible that the 3'-UTR, a stretch of RNA not occupied by ribosomes, offers a favorable binding site for Gag.
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Affiliation(s)
- Mauricio Comas-Garcia
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Sean R Davis
- Genetics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA.
| | - Alan Rein
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
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18
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Mailler E, Bernacchi S, Marquet R, Paillart JC, Vivet-Boudou V, Smyth RP. The Life-Cycle of the HIV-1 Gag-RNA Complex. Viruses 2016; 8:E248. [PMID: 27626439 DOI: 10.3390/v8090248] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/30/2016] [Accepted: 09/02/2016] [Indexed: 12/16/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) replication is a highly regulated process requiring the recruitment of viral and cellular components to the plasma membrane for assembly into infectious particles. This review highlights the recent process of understanding the selection of the genomic RNA (gRNA) by the viral Pr55Gag precursor polyprotein, and the processes leading to its incorporation into viral particles.
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19
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Milev MP, Ravichandran M, Khan MF, Schriemer DC, Mouland AJ. Characterization of staufen1 ribonucleoproteins by mass spectrometry and biochemical analyses reveal the presence of diverse host proteins associated with human immunodeficiency virus type 1. Front Microbiol 2012; 3:367. [PMID: 23125841 PMCID: PMC3486646 DOI: 10.3389/fmicb.2012.00367] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 09/27/2012] [Indexed: 12/02/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) unspliced, 9 kb genomic RNA (vRNA) is exported from the nucleus for the synthesis of viral structural proteins and enzymes (Gag and Gag/Pol) and is then transported to sites of virus assembly where it is packaged into progeny virions. vRNA co-exists in the cytoplasm in the context of the HIV-1 ribonucleoprotein (RNP) that is currently defined by the presence of Gag and several host proteins including the double-stranded RNA-binding protein, Staufen1. In this study we isolated Staufen1 RNP complexes derived from HIV-1-expressing cells using tandem affinity purification and have identified multiple host protein components by mass spectrometry. Four viral proteins, including Gag, Gag/Pol, Env and Nef as well as >200 host proteins were identified in these RNPs. Moreover, HIV-1 induces both qualitative and quantitative differences in host protein content in these RNPs. 22% of Staufen1-associated factors are virion-associated suggesting that the RNP could be a vehicle to achieve this. In addition, we provide evidence on how HIV-1 modulates the composition of cytoplasmic Staufen1 RNPs. Biochemical fractionation by density gradient analyses revealed new facets on the assembly of Staufen1 RNPs. The assembly of dense Staufen1 RNPs that contain Gag and several host proteins were found to be entirely RNA-dependent but their assembly appeared to be independent of Gag expression. Gag-containing complexes fractionated into a lighter and another, more dense pool. Lastly, Staufen1 depletion studies demonstrated that the previously characterized Staufen1 HIV-1-dependent RNPs are most likely aggregates of smaller RNPs that accumulate at juxtanuclear domains. The molecular characterization of Staufen1 HIV-1 RNPs will offer important information on virus-host cell interactions and on the elucidation of the function of these RNPs for the transport of Gag and the fate of the unspliced vRNA in HIV-1-producing cells.
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Affiliation(s)
- Miroslav P Milev
- HIV-1 Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital Montréal, QC, Canada ; Division of Experimental Medicine, Department of Medicine, McGill University Montreal, QC, Canada
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Mougel M, Cimarelli A, Darlix JL. Implications of the nucleocapsid and the microenvironment in retroviral reverse transcription. Viruses 2010; 2:939-960. [PMID: 21994662 PMCID: PMC3185662 DOI: 10.3390/v2040939] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 03/03/2010] [Accepted: 04/01/2010] [Indexed: 01/21/2023] Open
Abstract
This mini-review summarizes the process of reverse-transcription, an obligatory step in retrovirus replication during which the retroviral RNA/DNA-dependent DNA polymerase (RT) copies the single-stranded genomic RNA to generate the double-stranded viral DNA while degrading the genomic RNA via its associated RNase H activity. The hybridization of complementary viral sequences by the nucleocapsid protein (NC) receives a special focus, since it acts to chaperone the strand transfers obligatory for synthesis of the complete viral DNA and flanking long terminal repeats (LTR). Since the physiological microenvironment can impact on reverse-transcription, this mini-review also focuses on factors present in the intra-cellular or extra-cellular milieu that can drastically influence both the timing and the activity of reverse-transcription and hence virus infectivity.
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Affiliation(s)
- Marylène Mougel
- CPBS, UMR5236 CNRS, UMI, 4 bd Henri IV, 34965 Montpellier, France; E-Mail:
| | - Andrea Cimarelli
- LaboRetro Unité de Virologie humaine INSERM #758, IFR128, ENS Lyon, 46 Allée d’Italie, 69364 Lyon, France; E-Mail:
| | - Jean-Luc Darlix
- LaboRetro Unité de Virologie humaine INSERM #758, IFR128, ENS Lyon, 46 Allée d’Italie, 69364 Lyon, France; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +33 472728169; Fax: +33 472728137
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