1
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Majeed S, Adetuyi O, Borbat PP, Majharul Islam M, Ishola O, Zhao B, Georgieva ER. Insights into the oligomeric structure of the HIV-1 Vpu protein. J Struct Biol 2023; 215:107943. [PMID: 36796461 PMCID: PMC10257199 DOI: 10.1016/j.jsb.2023.107943] [Citation(s) in RCA: 5] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 02/16/2023]
Abstract
The HIV-1-encoded protein Vpu forms an oligomeric ion channel/pore in membranes and interacts with host proteins to support the virus lifecycle. However, Vpu molecular mechanisms are currently not well understood. Here, we report on the Vpu oligomeric organization under membrane and aqueous conditions and provide insights into how the Vpu environment affects the oligomer formation. For these studies, we designed a maltose-binding protein (MBP)-Vpu chimera protein and produced it in E. coli in soluble form. We analyzed this protein using analytical size-exclusion chromatography (SEC), negative staining electron microscopy (nsEM), and electron paramagnetic resonance (EPR) spectroscopy. Surprisingly, we found that MBP-Vpu formed stable oligomers in solution, seemingly driven by Vpu transmembrane domain self-association. A coarse modeling of nsEM data as well as SEC and EPR data suggests that these oligomers most likely are pentamers, similar to what was reported regarding membrane-bound Vpu. We also noticed reduced MBP-Vpu oligomer stability upon reconstitution of the protein in β-DDM detergent and mixtures of lyso-PC/PG or DHPC/DHPG. In these cases, we observed greater oligomer heterogeneity, with MBP-Vpu oligomeric order generally lower than in solution; however, larger oligomers were also present. Notably, we found that in lyso-PC/PG, above a certain protein concentration, MBP-Vpu assembles into extended structures, which had not been reported for Vpu. Therefore, we captured various Vpu oligomeric forms, which can shed light on Vpu quaternary organization. Our findings could be useful in understanding Vpu organization and function in cellular membranes and could provide information regarding the biophysical properties of single-pass transmembrane proteins.
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Affiliation(s)
- Saman Majeed
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, United States
| | - Oluwatosin Adetuyi
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, United States
| | - Peter P Borbat
- Department of Chemistry and Chemical Biology and ACERT, Cornell University, Ithaca, NY 14853, United States
| | - Md Majharul Islam
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, United States
| | - Olamide Ishola
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, United States
| | - Bo Zhao
- College of Arts & Sciences Microscopy (CASM), Texas Tech University, Lubbock, TX 79409, United States
| | - Elka R Georgieva
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, United States.
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2
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Huang TC, Fischer WB. Predicting the Assembly of the Transmembrane Domains of Viral Channel Forming Proteins and Peptide Drug Screening Using a Docking Approach. Biomolecules 2022; 12:biom12121844. [PMID: 36551274 PMCID: PMC9775931 DOI: 10.3390/biom12121844] [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: 11/11/2022] [Revised: 11/29/2022] [Accepted: 12/06/2022] [Indexed: 12/14/2022] Open
Abstract
A de novo assembly algorithm is provided to propose the assembly of bitopic transmembrane domains (TMDs) of membrane proteins. The algorithm is probed using, in particular, viral channel forming proteins (VCPs) such as M2 of influenza A virus, E protein of severe acute respiratory syndrome corona virus (SARS-CoV), 6K of Chikungunya virus (CHIKV), SH of human respiratory syncytial virus (hRSV), and Vpu of human immunodeficiency virus type 2 (HIV-2). The generation of the structures is based on screening a 7-dimensional space. Assembly of the TMDs can be achieved either by simultaneously docking the individual TMDs or via a sequential docking. Scoring based on estimated binding energies (EBEs) of the oligomeric structures is obtained by the tilt to decipher the handedness of the bundles. The bundles match especially well for all-atom models of M2 referring to an experimentally reported tetrameric bundle. Docking of helical poly-peptides to experimental structures of M2 and E protein identifies improving EBEs for positively charged (K,R,H) and aromatic amino acids (F,Y,W). Data are improved when using polypeptides for which the coordinates of the amino acids are adapted to the Cα coordinates of the respective experimentally derived structures of the TMDs of the target proteins.
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3
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Alzahrani N, Wu MJ, Sousa CF, Kalinina OV, Welsch C, Yi M. SPCS1-Dependent E2-p7 processing determines HCV Assembly efficiency. PLoS Pathog 2022; 18:e1010310. [PMID: 35130329 PMCID: PMC8853643 DOI: 10.1371/journal.ppat.1010310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 08/27/2021] [Revised: 02/17/2022] [Accepted: 01/26/2022] [Indexed: 11/18/2022] Open
Abstract
Recent studies identified signal peptidase complex subunit 1 (SPCS1) as a proviral host factor for Flaviviridae viruses, including HCV. One of the SPCS1’s roles in flavivirus propagation was attributed to its regulation of signal peptidase complex (SPC)-mediated processing of flavivirus polyprotein, especially C-prM junction. However, whether SPCS1 also regulates any SPC-mediated processing sites within HCV polyprotein remains unclear. In this study, we determined that loss of SPCS1 specifically impairs the HCV E2-p7 processing by the SPC. We also determined that efficient separation of E2 and p7, regardless of its dependence on SPC-mediated processing, leads to SPCS1 dispensable for HCV assembly These results suggest that SPCS1 regulates HCV assembly by facilitating the SPC-mediated processing of E2-p7 precursor. Structural modeling suggests that intrinsically delayed processing of the E2-p7 is likely caused by the structural rigidity of p7 N-terminal transmembrane helix-1 (p7/TM1/helix-1), which has mostly maintained membrane-embedded conformations during molecular dynamics (MD) simulations. E2-p7-processing-impairing p7 mutations narrowed the p7/TM1/helix-1 bending angle against the membrane, resulting in closer membrane embedment of the p7/TM1/helix-1 and less access of E2-p7 junction substrate to the catalytic site of the SPC, located well above the membrane in the ER lumen. Based on these results we propose that the key mechanism of action of SPCS1 in HCV assembly is to facilitate the E2-p7 processing by enhancing the E2-p7 junction site presentation to the SPC active site. By providing evidence that SPCS1 facilitates HCV assembly by regulating SPC-mediated cleavage of E2-p7 junction, equivalent to the previously established role of this protein in C-prM junction processing in flavivirus, this study establishes the common role of SPCS1 in Flaviviridae family virus propagation as to exquisitely regulate the SPC-mediated processing of specific, suboptimal target sites.
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Affiliation(s)
- Nabeel Alzahrani
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Ming-Jhan Wu
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Carla F. Sousa
- Drug Bioinformatics Group, HIPS, HZI, Saarbrücken, Germany
| | - Olga V. Kalinina
- Drug Bioinformatics Group, HIPS, HZI, Saarbrücken, Germany
- Medical Faculty, Saarland University, Homburg, Germany
| | - Christoph Welsch
- Department of Internal Medicine 1, Goethe University Hospital, Frankfurt am Main, Germany
| | - MinKyung Yi
- Department of Microbiology and Immunology, University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- * E-mail:
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4
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Gargan S, Stevenson NJ. Unravelling the Immunomodulatory Effects of Viral Ion Channels, towards the Treatment of Disease. Viruses 2021; 13:2165. [PMID: 34834972 PMCID: PMC8618147 DOI: 10.3390/v13112165] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 07/12/2021] [Revised: 09/07/2021] [Accepted: 10/10/2021] [Indexed: 02/07/2023] Open
Abstract
The current COVID-19 pandemic has highlighted the need for the research community to develop a better understanding of viruses, in particular their modes of infection and replicative lifecycles, to aid in the development of novel vaccines and much needed anti-viral therapeutics. Several viruses express proteins capable of forming pores in host cellular membranes, termed "Viroporins". They are a family of small hydrophobic proteins, with at least one amphipathic domain, which characteristically form oligomeric structures with central hydrophilic domains. Consequently, they can facilitate the transport of ions through the hydrophilic core. Viroporins localise to host membranes such as the endoplasmic reticulum and regulate ion homeostasis creating a favourable environment for viral infection. Viroporins also contribute to viral immune evasion via several mechanisms. Given that viroporins are often essential for virion assembly and egress, and as their structural features tend to be evolutionarily conserved, they are attractive targets for anti-viral therapeutics. This review discusses the current knowledge of several viroporins, namely Influenza A virus (IAV) M2, Human Immunodeficiency Virus (HIV)-1 Viral protein U (Vpu), Hepatitis C Virus (HCV) p7, Human Papillomavirus (HPV)-16 E5, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) Open Reading Frame (ORF)3a and Polyomavirus agnoprotein. We highlight the intricate but broad immunomodulatory effects of these viroporins and discuss the current antiviral therapies that target them; continually highlighting the need for future investigations to focus on novel therapeutics in the treatment of existing and future emergent viruses.
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Affiliation(s)
- Siobhan Gargan
- Viral Immunology Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, D02 R590 Dublin, Ireland;
| | - Nigel J. Stevenson
- Viral Immunology Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, D02 R590 Dublin, Ireland;
- Viral Immunology Group, Royal College of Surgeons in Ireland-Medical University of Bahrain, Manama 15503, Bahrain
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5
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O’Donoghue SI, Schafferhans A, Sikta N, Stolte C, Kaur S, Ho BK, Anderson S, Procter JB, Dallago C, Bordin N, Adcock M, Rost B. SARS-CoV-2 structural coverage map reveals viral protein assembly, mimicry, and hijacking mechanisms. Mol Syst Biol 2021; 17:e10079. [PMID: 34519429 PMCID: PMC8438690 DOI: 10.15252/msb.202010079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 10/24/2020] [Revised: 08/05/2021] [Accepted: 08/06/2021] [Indexed: 01/18/2023] Open
Abstract
We modeled 3D structures of all SARS-CoV-2 proteins, generating 2,060 models that span 69% of the viral proteome and provide details not available elsewhere. We found that ˜6% of the proteome mimicked human proteins, while ˜7% was implicated in hijacking mechanisms that reverse post-translational modifications, block host translation, and disable host defenses; a further ˜29% self-assembled into heteromeric states that provided insight into how the viral replication and translation complex forms. To make these 3D models more accessible, we devised a structural coverage map, a novel visualization method to show what is-and is not-known about the 3D structure of the viral proteome. We integrated the coverage map into an accompanying online resource (https://aquaria.ws/covid) that can be used to find and explore models corresponding to the 79 structural states identified in this work. The resulting Aquaria-COVID resource helps scientists use emerging structural data to understand the mechanisms underlying coronavirus infection and draws attention to the 31% of the viral proteome that remains structurally unknown or dark.
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MESH Headings
- Amino Acid Transport Systems, Neutral/chemistry
- Amino Acid Transport Systems, Neutral/genetics
- Amino Acid Transport Systems, Neutral/metabolism
- Angiotensin-Converting Enzyme 2/chemistry
- Angiotensin-Converting Enzyme 2/genetics
- Angiotensin-Converting Enzyme 2/metabolism
- Binding Sites
- COVID-19/genetics
- COVID-19/metabolism
- COVID-19/virology
- Computational Biology/methods
- Coronavirus Envelope Proteins/chemistry
- Coronavirus Envelope Proteins/genetics
- Coronavirus Envelope Proteins/metabolism
- Coronavirus Nucleocapsid Proteins/chemistry
- Coronavirus Nucleocapsid Proteins/genetics
- Coronavirus Nucleocapsid Proteins/metabolism
- Host-Pathogen Interactions/genetics
- Humans
- Mitochondrial Membrane Transport Proteins/chemistry
- Mitochondrial Membrane Transport Proteins/genetics
- Mitochondrial Membrane Transport Proteins/metabolism
- Mitochondrial Precursor Protein Import Complex Proteins
- Models, Molecular
- Molecular Mimicry
- Neuropilin-1/chemistry
- Neuropilin-1/genetics
- Neuropilin-1/metabolism
- Phosphoproteins/chemistry
- Phosphoproteins/genetics
- Phosphoproteins/metabolism
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Interaction Domains and Motifs
- Protein Interaction Mapping/methods
- Protein Multimerization
- Protein Processing, Post-Translational
- SARS-CoV-2/chemistry
- SARS-CoV-2/genetics
- SARS-CoV-2/metabolism
- Spike Glycoprotein, Coronavirus/chemistry
- Spike Glycoprotein, Coronavirus/genetics
- Spike Glycoprotein, Coronavirus/metabolism
- Viral Matrix Proteins/chemistry
- Viral Matrix Proteins/genetics
- Viral Matrix Proteins/metabolism
- Viroporin Proteins/chemistry
- Viroporin Proteins/genetics
- Viroporin Proteins/metabolism
- Virus Replication
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Affiliation(s)
- Seán I O’Donoghue
- Garvan Institute of Medical ResearchDarlinghurstNSWAustralia
- CSIRO Data61CanberraACTAustralia
- School of Biotechnology and Biomolecular Sciences (UNSW)KensingtonNSWAustralia
| | - Andrea Schafferhans
- Garvan Institute of Medical ResearchDarlinghurstNSWAustralia
- Department of Bioengineering SciencesWeihenstephan‐Tr. University of Applied SciencesFreisingGermany
- Department of InformaticsBioinformatics & Computational BiologyTechnical University of MunichMunichGermany
| | - Neblina Sikta
- Garvan Institute of Medical ResearchDarlinghurstNSWAustralia
| | | | - Sandeep Kaur
- Garvan Institute of Medical ResearchDarlinghurstNSWAustralia
- School of Biotechnology and Biomolecular Sciences (UNSW)KensingtonNSWAustralia
| | - Bosco K Ho
- Garvan Institute of Medical ResearchDarlinghurstNSWAustralia
| | | | | | - Christian Dallago
- Department of InformaticsBioinformatics & Computational BiologyTechnical University of MunichMunichGermany
| | - Nicola Bordin
- Institute of Structural and Molecular BiologyUniversity College LondonLondonUK
| | | | - Burkhard Rost
- Department of InformaticsBioinformatics & Computational BiologyTechnical University of MunichMunichGermany
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6
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Su CM, Wang L, Yoo D. Activation of NF-κB and induction of proinflammatory cytokine expressions mediated by ORF7a protein of SARS-CoV-2. Sci Rep 2021; 11:13464. [PMID: 34188167 PMCID: PMC8242070 DOI: 10.1038/s41598-021-92941-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [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: 04/13/2021] [Accepted: 06/17/2021] [Indexed: 02/07/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for coronavirus disease 2019 (COVID-19) that emerged in human populations recently. Severely ill COVID-19 patients exhibit the elevation of proinflammatory cytokines, and such an unbalanced production of proinflammatory cytokines is linked to acute respiratory distress syndrome with high mortality in COVID-19 patients. Our study provides evidence that the ORF3a, M, ORF7a, and N proteins of SARS-CoV-2 were NF-κB activators. The viral sequence from infected zoo lions belonged to clade V, and a single mutation of G251V is found for ORF3a gene compared to all other clades. No significant functional difference was found for clade V ORF3a, indicating the NF-κB activation is conserved among COVID-19 variants. Of the four viral proteins, the ORF7a protein induced the NF-κB dictated proinflammatory cytokines including IL-1α, IL-1β, IL-6, IL-8, IL-10, TNF-α, and IFNβ. The ORF7a protein also induced IL-3, IL-4, IL-7, IL-23. Of 15 different chemokines examined in the study, CCL11, CCL17, CCL19, CCL20, CCL21, CCL22, CCL25, CCL26, CCL27, and CXCL9 were significantly upregulated by ORF7. These cytokines and chemokines were frequently elevated in severely ill COVID-19 patients. Our data provide an insight into how SARS-CoV-2 modulates NF-κB signaling and inflammatory cytokine expressions. The ORF7a protein may be a desirable target for strategic developments to minimize uncontrolled inflammation in COVID-19 patients.
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Affiliation(s)
- Chia-Ming Su
- Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 Lincoln Ave, Urbana, IL, 61802, USA
| | - Leyi Wang
- Department of Veterinary Diagnostic Laboratory and Department of Veterinary Clinical Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Dongwan Yoo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 Lincoln Ave, Urbana, IL, 61802, USA.
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7
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Cao Y, Yang R, Lee I, Zhang W, Sun J, Wang W, Meng X. Characterization of the SARS-CoV-2 E Protein: Sequence, Structure, Viroporin, and Inhibitors. Protein Sci 2021; 30:1114-1130. [PMID: 33813796 PMCID: PMC8138525 DOI: 10.1002/pro.4075] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [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: 02/01/2021] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 12/19/2022]
Abstract
The COVID-19 epidemic is one of the most influential epidemics in history. Understanding the impact of coronaviruses (CoVs) on host cells is very important for disease treatment. The SARS-CoV-2 envelope (E) protein is a small structural protein involved in many aspects of the viral life cycle. The E protein promotes the packaging and reproduction of the virus, and deletion of this protein weakens or even abolishes the virulence. This review aims to establish new knowledge by combining recent advances in the study of the SARS-CoV-2 E protein and by comparing it with the SARS-CoV E protein. The E protein amino acid sequence, structure, self-assembly characteristics, viroporin mechanisms and inhibitors are summarized and analyzed herein. Although the mechanisms of the SARS-CoV-2 and SARS-CoV E proteins are similar in many respects, specific studies on the SARS-CoV-2 E protein, for both monomers and oligomers, are still lacking. A comprehensive understanding of this protein should prompt further studies on the design and characterization of effective targeted therapeutic measures.
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Affiliation(s)
- Yipeng Cao
- Tianjin Medical University Cancer Institute and HospitalKey Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center for CancerTianjinPeople's Republic of China
- National Supercomputer Center in TianjinTEDA‐Tianjin Economic‐Technological Development AreaTianjinPeople's Republic of China
| | - Rui Yang
- Department of Infection and ImmunityTianjin Union Medical Center, Nankai University Affiliated HospitalTianjinPeople's Republic of China
| | - Imshik Lee
- College of PhysicsNankai UniversityTianjinPeople's Republic of China
| | - Wenwen Zhang
- Tianjin Medical University Cancer Institute and HospitalKey Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center for CancerTianjinPeople's Republic of China
| | - Jiana Sun
- Tianjin Medical University Cancer Institute and HospitalKey Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center for CancerTianjinPeople's Republic of China
| | - Wei Wang
- Tianjin Medical University Cancer Institute and HospitalKey Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center for CancerTianjinPeople's Republic of China
| | - Xiangfei Meng
- National Supercomputer Center in TianjinTEDA‐Tianjin Economic‐Technological Development AreaTianjinPeople's Republic of China
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8
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Oulas A, Zanti M, Tomazou M, Zachariou M, Minadakis G, Bourdakou MM, Pavlidis P, Spyrou GM. Generalized linear models provide a measure of virulence for specific mutations in SARS-CoV-2 strains. PLoS One 2021; 16:e0238665. [PMID: 33497392 PMCID: PMC7837476 DOI: 10.1371/journal.pone.0238665] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [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: 08/26/2020] [Accepted: 01/06/2021] [Indexed: 01/01/2023] Open
Abstract
This study aims to highlight SARS-COV-2 mutations which are associated with increased or decreased viral virulence. We utilize genetic data from all strains available from GISAID and countries' regional information, such as deaths and cases per million, as well as COVID-19-related public health austerity measure response times. Initial indications of selective advantage of specific mutations can be obtained from calculating their frequencies across viral strains. By applying modelling approaches, we provide additional information that is not evident from standard statistics or mutation frequencies alone. We therefore, propose a more precise way of selecting informative mutations. We highlight two interesting mutations found in genes N (P13L) and ORF3a (Q57H). The former appears to be significantly associated with decreased deaths and cases per million according to our models, while the latter shows an opposing association with decreased deaths and increased cases per million. Moreover, protein structure prediction tools show that the mutations infer conformational changes to the protein that significantly alter its structure when compared to the reference protein.
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Affiliation(s)
- Anastasis Oulas
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, Nicosia, Cyprus
- * E-mail:
| | - Maria Zanti
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, Nicosia, Cyprus
| | - Marios Tomazou
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, Nicosia, Cyprus
| | - Margarita Zachariou
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, Nicosia, Cyprus
| | - George Minadakis
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
| | - Marilena M. Bourdakou
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
| | - Pavlos Pavlidis
- Institute of Computer Science, Foundation for Research and Technology Hellas, Heraklion, Crete, Greece
| | - George M. Spyrou
- Bioinformatics Department, The Cyprus Institute of Neurology & Genetics, Nicosia, Cyprus
- The Cyprus School of Molecular Medicine, Nicosia, Cyprus
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9
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Saxena R, Saribas S, Jadiya P, Tomar D, Kaminski R, Elrod JW, Safak M. Human neurotropic polyomavirus, JC virus, agnoprotein targets mitochondrion and modulates its functions. Virology 2021; 553:135-153. [PMID: 33278736 PMCID: PMC7847276 DOI: 10.1016/j.virol.2020.11.004] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/12/2020] [Indexed: 01/18/2023]
Abstract
JC virus encodes an important regulatory protein, known as Agnoprotein (Agno). We have recently reported Agno's first protein-interactome with its cellular partners revealing that it targets various cellular networks and organelles, including mitochondria. Here, we report further characterization of the functional consequences of its mitochondrial targeting and demonstrated its co-localization with the mitochondrial networks and with the mitochondrial outer membrane. The mitochondrial targeting sequence (MTS) of Agno and its dimerization domain together play major roles in this targeting. Data also showed alterations in various mitochondrial functions in Agno-positive cells; including a significant reduction in mitochondrial membrane potential, respiration rates and ATP production. In contrast, a substantial increase in ROS production and Ca2+ uptake by the mitochondria were also observed. Finally, findings also revealed a significant decrease in viral replication when Agno MTS was deleted, highlighting a role for MTS in the function of Agno during the viral life cycle.
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Affiliation(s)
- Reshu Saxena
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA, 19140, USA
| | - Sami Saribas
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA, 19140, USA
| | - Pooja Jadiya
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, USA
| | - Dhanendra Tomar
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, USA
| | - Rafal Kaminski
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA, 19140, USA
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, USA
| | - Mahmut Safak
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA, 19140, USA.
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10
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Abstract
The SARS-CoV-2 3a protein is a putative ion channel implicated in virus life cycle and pathogenesis. We recently expressed, purified, and reconstituted 3a into lipid nanodiscs to solve its structure by cryo-EM to 2.1Å resolution. In this chapter, we describe methods we developed in order to facilitate the study of this protein in other laboratories. We emphasize factors that enabled rapid progression from gene sequence to reconstituted protein (3 weeks in the case of 3a) and provide general observations and tips for adapting these protocols to other membrane proteins of interest.
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Affiliation(s)
- David M Kern
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, United States; Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, United States; California Institute for Quantitative Biology (QB3), University of California Berkeley, Berkeley, CA, United States
| | - Stephen G Brohawn
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, United States; Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, United States; California Institute for Quantitative Biology (QB3), University of California Berkeley, Berkeley, CA, United States.
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