1
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Rao SS, Skinnemoen L, Fond AKS, Haugland GT. Analyses of the Mx family members in lumpfish: Molecular characterization, phylogeny, and gene expression analyses. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2024; 159:105225. [PMID: 38992732 DOI: 10.1016/j.dci.2024.105225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 07/05/2024] [Accepted: 07/05/2024] [Indexed: 07/13/2024]
Abstract
Members of the myxovirus resistance (Mx) protein family play an essential role in antiviral immunity. They are Dynamin-like GTPases, induced by interferons. In the current study, we have characterized two predicted MX genes (MX1 and MX2) from lumpfish (Cyclopterus lumpus L.), having 12 and 13 exons, respectively. Mx2 has two isoforms (Mx2-X1 and Mx2-X2) which differ in exon 1. The lumpfish Mx proteins contain an N-terminal Dynamin-like GTPase domain, the middle domain (MD) and GTPase effector domain (GED) characteristic for Mx proteins. Phylogenetic analyses grouped all the lumpfish Mx sequences in group 1, and synteny analyses showed that both genes were localized at chromosome 5 in proximity to the genes Tohc7, Atxn7 and Psmd6. In vitro stimulation experiment showed that both MX1 and MX2-X2 were highly upregulated upon exposure to poly(I:C), but not bacteria, 24 h post exposure, indicating their role in antiviral immunity.
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Affiliation(s)
- Shreesha Sadashiva Rao
- Department of Biological Sciences, Bergen High-Technology Centre, University of Bergen, Bergen, 5006, Norway
| | - Linda Skinnemoen
- Department of Biological Sciences, Bergen High-Technology Centre, University of Bergen, Bergen, 5006, Norway
| | - Amanda Kästel Sandal Fond
- Department of Biological Sciences, Bergen High-Technology Centre, University of Bergen, Bergen, 5006, Norway
| | - Gyri Teien Haugland
- Department of Biological Sciences, Bergen High-Technology Centre, University of Bergen, Bergen, 5006, Norway.
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2
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Umthong S, Timilsina U, D’Angelo MR, Salka K, Stavrou S. MARCH2, a T cell specific factor that restricts HIV-1 infection. PLoS Pathog 2024; 20:e1012330. [PMID: 39074162 PMCID: PMC11309421 DOI: 10.1371/journal.ppat.1012330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 08/08/2024] [Accepted: 06/07/2024] [Indexed: 07/31/2024] Open
Abstract
Membrane-associated RING-CH (MARCH) 2 is a member of the MARCH protein family of RING-CH finger E3 ubiquitin ligases that play important roles in regulating the levels of proteins found on the cell surface. MARCH1, 2 and 8 inhibit HIV-1 infection by preventing the incorporation of the envelope glycoproteins into nascent virions. However, a better understanding of the mechanism utilized by MARCH proteins to restrict HIV-1 infection is needed. In this report, we identify an amino acid in human MARCH2, absent in mouse MARCH2, critical for its antiretroviral function. Moreover, we map the domains of human MARCH2 critical for restricting as well as binding to the HIV-1 envelope glycoproteins. In addition, we demonstrate that MARCH2 is present inside nascent virions and reduces particle infectivity by blocking virus entry in a RING-CH-independent manner. Finally, we show that MARCH2 acts as an HIV-1 restriction factor only in primary CD4+ T cells and can prevent cell-to-cell transmission of HIV-1. Our findings reveal important new aspects of the antiviral mechanism utilized by human MARCH2 to restrict HIV-1 that have potential implications to all MARCH proteins with antiviral functions and their viral targets.
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Affiliation(s)
- Supawadee Umthong
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
- Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Uddhav Timilsina
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Mary R. D’Angelo
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Kyle Salka
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Spyridon Stavrou
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
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3
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Yi D, An N, Li Q, Liu Q, Shao H, Zhou R, Wang J, Zhang Y, Ma L, Guo F, Li X, Liu Z, Cen S. Interferon-induced MXB protein restricts vimentin-dependent viral infection. Acta Pharm Sin B 2024; 14:2520-2536. [PMID: 38828143 PMCID: PMC11143536 DOI: 10.1016/j.apsb.2024.03.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 02/16/2024] [Accepted: 03/14/2024] [Indexed: 06/05/2024] Open
Abstract
Type I interferon (IFN) inhibits a wide spectrum of viruses through stimulating the expression of antiviral proteins. As an IFN-induced protein, myxovirus resistance B (MXB) protein was reported to inhibit multiple highly pathogenic human viruses. It remains to be determined whether MXB employs a common mechanism to restrict different viruses. Here, we find that IFN alters the subcellular localization of hundreds of host proteins, and this IFN effect is partially lost upon MXB depletion. The results of our mechanistic study reveal that MXB recognizes vimentin (VIM) and recruits protein kinase B (AKT) to phosphorylate VIM at amino acid S38, which leads to reorganization of the VIM network and impairment of intracellular trafficking of virus protein complexes, hence causing a restriction of virus infection. These results highlight a new function of MXB in modulating VIM-mediated trafficking, which may lead towards a novel broad-spectrum antiviral strategy to control a large group of viruses that depend on VIM for successful replication.
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Affiliation(s)
- Dongrong Yi
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Ni An
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Quanjie Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Qian Liu
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Huihan Shao
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Rui Zhou
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Jing Wang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Yongxin Zhang
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Ling Ma
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Fei Guo
- Institute of Pathogen Biology, Chinese Academy of Medical Science, Beijing 100730, China
| | - Xiaoyu Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Zhenlong Liu
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada
| | - Shan Cen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
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4
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Hu Y, Wu X, Tian Y, Jiang D, Ren J, Li Z, Ding X, Zhang Q, Yoo D, Miller LC, Lee C, Cong X, Li J, Du Y, Qi J. GTPase activity of porcine Mx1 plays a dominant role in inhibiting the N-Nsp9 interaction and thus inhibiting PRRSV replication. J Virol 2024; 98:e0184423. [PMID: 38436247 PMCID: PMC11019876 DOI: 10.1128/jvi.01844-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 02/08/2024] [Indexed: 03/05/2024] Open
Abstract
Porcine Mx1 is a type of interferon-induced GTPase that inhibits the replication of certain RNA viruses. However, the antiviral effects and the underlying mechanism of porcine Mx1 for porcine reproductive and respiratory syndrome virus (PRRSV) remain unknown. In this study, we demonstrated that porcine Mx1 could significantly inhibit PRRSV replication in MARC-145 cells. By Mx1 segment analysis, it was indicated that the GTPase domain (68-341aa) was the functional area to inhibit PRRSV replication and that Mx1 interacted with the PRRSV-N protein through the GTPase domain (68-341aa) in the cytoplasm. Amino acid residues K295 and K299 in the G domain of Mx1 were the key sites for Mx1-N interaction while mutant proteins Mx1(K295A) and Mx1(K299A) still partially inhibited PRRSV replication. Furthermore, we found that the GTPase activity of Mx1 was dominant for Mx1 to inhibit PRRSV replication but was not essential for Mx1-N interaction. Finally, mechanistic studies demonstrated that the GTPase activity of Mx1 played a dominant role in inhibiting the N-Nsp9 interaction and that the interaction between Mx1 and N partially inhibited the N-Nsp9 interaction. We propose that the complete anti-PRRSV mechanism of porcine Mx1 contains a two-step process: Mx1 binds to the PRRSV-N protein and subsequently disrupts the N-Nsp9 interaction by a process requiring the GTPase activity of Mx1. Taken together, the results of our experiments describe for the first time a novel mechanism by which porcine Mx1 evolves to inhibit PRRSV replication. IMPORTANCE Mx1 protein is a key mediator of the interferon-induced antiviral response against a wide range of viruses. How porcine Mx1 affects the replication of porcine reproductive and respiratory syndrome virus (PRRSV) and its biological function has not been studied. Here, we show that Mx1 protein inhibits PRRSV replication by interfering with N-Nsp9 interaction. Furthermore, the GTPase activity of porcine Mx1 plays a dominant role and the Mx1-N interaction plays an assistant role in this interference process. This study uncovers a novel mechanism evolved by porcine Mx1 to exert anti-PRRSV activities.
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Affiliation(s)
- Yue Hu
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Xiangju Wu
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Yunfei Tian
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Dandan Jiang
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Jinrui Ren
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Ziyong Li
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Xiuliang Ding
- Animal Nutrition Institute, Chongqing Academy of Animal Sciences, Chongqing, China
| | - Quanfang Zhang
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Dongwan Yoo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Laura C. Miller
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, USA
| | - Changhee Lee
- College of Veterinary Medicine and Virus Vaccine Research Center, Gyeongsang National University, Jinju, Republic of Korea
| | - Xiaoyan Cong
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Juntong Li
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Yijun Du
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
| | - Jing Qi
- Shandong Key Laboratory of Animal Disease Control and Breeding/Key Laboratory of Livestock and Poultry Multi-omics of MARA, Institute of Animal Science and Veterinary Medicine, Institute of Crop Germplasm Resources, Shandong Academy of Agricultural Sciences, Jinan, Shandong, China
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5
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Twentyman J, Emerman M, Ohainle M. Capsid-dependent lentiviral restrictions. J Virol 2024; 98:e0030824. [PMID: 38497663 PMCID: PMC11019884 DOI: 10.1128/jvi.00308-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024] Open
Abstract
Host antiviral proteins inhibit primate lentiviruses and other retroviruses by targeting many features of the viral life cycle. The lentiviral capsid protein and the assembled viral core are known to be inhibited through multiple, directly acting antiviral proteins. Several phenotypes, including those known as Lv1 through Lv5, have been described as cell type-specific blocks to infection against some but not all primate lentiviruses. Here we review important features of known capsid-targeting blocks to infection together with several blocks to infection for which the genes responsible for the inhibition still remain to be identified. We outline the features of these blocks as well as how current methodologies are now well suited to find these antiviral genes and solve these long-standing mysteries in the HIV and retrovirology fields.
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Affiliation(s)
- Joy Twentyman
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Michael Emerman
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Molly Ohainle
- Department of Molecular and Cell Biology, Division of Immunology and Molecular Medicine, University of California Berkeley, Berkeley, California, USA
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6
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Layish B, Goli R, Flick H, Huang SW, Zhang RZ, Kvaratskhelia M, Kane M. Virus specificity and nucleoporin requirements for MX2 activity are affected by GTPase function and capsid-CypA interactions. PLoS Pathog 2024; 20:e1011830. [PMID: 38512975 PMCID: PMC10986937 DOI: 10.1371/journal.ppat.1011830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 04/02/2024] [Accepted: 02/29/2024] [Indexed: 03/23/2024] Open
Abstract
Human myxovirus resistance 2 (MX2/MXB) is an interferon-induced GTPase that inhibits human immunodeficiency virus-1 (HIV-1) infection by preventing nuclear import of the viral preintegration complex. The HIV-1 capsid (CA) is the major viral determinant for sensitivity to MX2, and complex interactions between MX2, CA, nucleoporins (Nups), cyclophilin A (CypA), and other cellular proteins influence the outcome of viral infection. To explore the interactions between MX2, the viral CA, and CypA, we utilized a CRISPR-Cas9/AAV approach to generate CypA knock-out cell lines as well as cells that express CypA from its endogenous locus, but with specific point mutations that would abrogate CA binding but should not affect enzymatic activity or cellular function. We found that infection of CypA knock-out and point mutant cell lines with wild-type HIV-1 and CA mutants recapitulated the phenotypes observed upon cyclosporine A (CsA) addition, indicating that effects of CsA treatment are the direct result of blocking CA-CypA interactions and are therefore independent from potential interactions between CypA and MX2 or other cellular proteins. Notably, abrogation of GTP hydrolysis by MX2 conferred enhanced antiviral activity when CA-CypA interactions were abolished, and this effect was not mediated by the CA-binding residues in the GTPase domain, or by phosphorylation of MX2 at position T151. We additionally found that elimination of GTPase activity also altered the Nup requirements for MX2 activity. Our data demonstrate that the antiviral activity of MX2 is affected by CypA-CA interactions in a virus-specific and GTPase activity-dependent manner. These findings further highlight the importance of the GTPase domain of MX2 in regulation of substrate specificity and interaction with nucleocytoplasmic trafficking pathways.
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Affiliation(s)
- Bailey Layish
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Ram Goli
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Haley Flick
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Szu-Wei Huang
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Robert Z. Zhang
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Mamuka Kvaratskhelia
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Melissa Kane
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
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7
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Jang S, Engelman AN. Capsid-host interactions for HIV-1 ingress. Microbiol Mol Biol Rev 2023; 87:e0004822. [PMID: 37750702 PMCID: PMC10732038 DOI: 10.1128/mmbr.00048-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023] Open
Abstract
The HIV-1 capsid, composed of approximately 1,200 copies of the capsid protein, encases genomic RNA alongside viral nucleocapsid, reverse transcriptase, and integrase proteins. After cell entry, the capsid interacts with a myriad of host factors to traverse the cell cytoplasm, pass through the nuclear pore complex (NPC), and then traffic to chromosomal sites for viral DNA integration. Integration may very well require the dissolution of the capsid, but where and when this uncoating event occurs remains hotly debated. Based on size constraints, a long-prevailing view was that uncoating preceded nuclear transport, but recent research has indicated that the capsid may remain largely intact during nuclear import, with perhaps some structural remodeling required for NPC traversal. Completion of reverse transcription in the nucleus may further aid capsid uncoating. One canonical type of host factor, typified by CPSF6, leverages a Phe-Gly (FG) motif to bind capsid. Recent research has shown these peptides reside amid prion-like domains (PrLDs), which are stretches of protein sequence devoid of charged residues. Intermolecular PrLD interactions along the exterior of the capsid shell impart avid host factor binding for productive HIV-1 infection. Herein we overview capsid-host interactions implicated in HIV-1 ingress and discuss important research questions moving forward. Highlighting clinical relevance, the long-acting ultrapotent inhibitor lenacapavir, which engages the same capsid binding pocket as FG host factors, was recently approved to treat people living with HIV.
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Affiliation(s)
- Sooin Jang
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Alan N. Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
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8
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Layish B, Goli R, Flick H, Huang SW, Zhang RZ, Kvaratskhelia M, Kane M. Virus specificity and nucleoporin requirements for MX2 activity are affected by GTPase function and capsid-CypA interactions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.16.567336. [PMID: 38014352 PMCID: PMC10680775 DOI: 10.1101/2023.11.16.567336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Human myxovirus resistance 2 (MX2/MXB) is an interferon-induced GTPase that inhibits human immunodeficiency virus-1 (HIV-1) infection by preventing nuclear import of the viral preintegration complex. The HIV-1 capsid (CA) is the major viral determinant for sensitivity to MX2, and complex interactions between MX2, CA, nucleoporins (Nups), cyclophilin A (CypA), and other cellular proteins influence the outcome of viral infection. To explore the interactions between MX2, the viral CA, and CypA, we utilized a CRISPR-Cas9/AAV approach to generate CypA knock-out cell lines as well as cells that express CypA from its endogenous locus, but with specific point mutations that would abrogate CA binding but should not affect enzymatic activity or cellular function. We found that infection of CypA knock-out and point mutant cell lines with wild-type HIV-1 and CA mutants recapitulated the phenotypes observed upon cyclosporine A (CsA) addition, indicating that effects of CsA treatment are the direct result of blocking CA-CypA interactions and are therefore independent from potential interactions between CypA and MX2 or other cellular proteins. Notably, abrogation of GTP hydrolysis by MX2 conferred enhanced antiviral activity when CA-CypA interactions were abolished, and this effect was not mediated by the CA-binding residues in the GTPase domain, or by phosphorylation of MX2 at position T151. We additionally found that elimination of GTPase activity also altered the Nup requirements for MX2 activity. Our data demonstrate that the antiviral activity of MX2 is affected by CypA-CA interactions in a virus-specific and GTPase activity-dependent manner. These findings further highlight the importance of the GTPase domain of MX2 in regulation of substrate specificity and interaction with nucleocytoplasmic trafficking pathways.
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Affiliation(s)
- Bailey Layish
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Ram Goli
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Haley Flick
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Szu-Wei Huang
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Robert Z Zhang
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Mamuka Kvaratskhelia
- Division of Infectious Diseases, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Melissa Kane
- Department of Pediatrics, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
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9
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Bayer A, Child SJ, Malik HS, Geballe AP. A single polymorphic residue in humans underlies species-specific restriction of HSV-1 by the antiviral protein MxB. J Virol 2023; 97:e0083023. [PMID: 37796130 PMCID: PMC10617587 DOI: 10.1128/jvi.00830-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/23/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE Herpesviruses present a major global disease burden. Understanding the host cell mechanisms that block viral infections, as well as how viruses can evolve to counteract these host defenses, is critically important for understanding viral disease pathogenesis. This study reveals that the major human variant of the antiviral protein myxovirus resistance protein B (MxB) inhibits the human pathogen herpes simplex virus (HSV-1), whereas a minor human variant and orthologous MxB genes from even closely related primates do not. Thus, in contrast to the many antagonistic virus-host interactions in which the virus is successful in thwarting the host's defense systems, here the human gene appears to be at least temporarily winning at this interface of the primate-herpesvirus evolutionary arms race. Our findings further show that a polymorphism at amino acid 83 in a small fraction of the human population is sufficient to abrogate MxB's ability to inhibit HSV-1, which could have important implications for human susceptibility to HSV-1 pathogenesis.
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Affiliation(s)
- Avraham Bayer
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Stephanie J. Child
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Harmit S. Malik
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Center, Seattle, Washington, USA
| | - Adam P. Geballe
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Clinical Research Division, Fred Hutchinson Cancer Center, Seattle, Washington, USA
- Department of Medicine, University of Washington, Seattle, Washington, USA
- Department of Microbiology, University of Washington, Seattle, Washington, USA
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10
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Umthong S, Timilsina U, D’Angelo M, Stavrou S. Determining the antiviral mechanism of MARCH2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.18.558306. [PMID: 37786722 PMCID: PMC10541590 DOI: 10.1101/2023.09.18.558306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Membrane-associated RING-CH (MARCH) 2 protein is a member of the MARCH protein family of RING-CH finger E3 ubiquitin ligases that have important functions in regulating the levels of proteins found on the cell surface. MARCH1, 2 and 8 inhibit HIV-1 infection by preventing the incorporation of the envelope glycoproteins in nascent virions. However, a better understanding on the mechanism utilized by MARCH proteins to restrict HIV-1 is needed. In this report, we identify an amino acid in human MARCH2, that is absent in mouse MARCH2, critical for its antiretroviral function. Moreover, we map the domains of human MARCH2 critical for restricting as well as binding to the HIV-1 envelope glycoproteins. Our findings reveal important new aspects of the antiviral mechanism utilized by human MARCH2 to restrict HIV-1 that have potential implications to all MARCH proteins with antiviral functions.
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Affiliation(s)
- Supawadee Umthong
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
- Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Uddhav Timilsina
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Mary D’Angelo
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Spyridon Stavrou
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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11
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Bayer A, Child SJ, Malik HS, Geballe AP. A single polymorphic residue in humans underlies species-specific restriction of HSV-1 by the antiviral protein MxB. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542951. [PMID: 37398298 PMCID: PMC10312577 DOI: 10.1101/2023.05.30.542951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Myxovirus resistance proteins (MxA and MxB) are interferon-induced proteins that exert antiviral activity against a diverse range of RNA and DNA viruses. In primates, MxA has been shown to inhibit myxoviruses, bunyaviruses, and hepatitis B virus, whereas MxB restricts retroviruses and herpesviruses. As a result of their conflicts with viruses, both genes have been undergoing diversifying selection during primate evolution. Here, we investigate how MxB evolution in primates has affected its restriction of herpesviruses. In contrast to human MxB, we find that most primate orthologs, including the closely related chimpanzee MxB, do not inhibit HSV-1 replication. However, all primate MxB orthologs tested restrict human cytomegalovirus. Through the generation of human and chimpanzee MxB chimeras we show that a single residue, M83, is the key determinant of restriction of HSV-1 replication. Humans are the only primate species known to encode a methionine at this position, whereas most other primate species encode a lysine. Residue 83 is also the most polymorphic residue in MxB in human populations, with M83 being the most common variant. However, ∼2.5% of human MxB alleles encode a threonine at this position, which does not restrict HSV-1. Thus, a single amino acid variant in MxB, which has recently risen to high frequency in humans, has endowed humans with HSV-1 antiviral activity. Importance Herpesviruses present a major global disease burden. Understanding the host cell mechanisms that block viral infections as well as how viruses can evolve to counteract these host defenses is critically important for understanding viral disease pathogenesis, and for developing therapeutic tools aimed at treating or preventing viral infections. Additionally, understanding how these host and viral mechanisms adapt to counter one another can aid in identifying the risks of, and barriers to, cross-species transmission events. As highlighted by the recent SARS-CoV-2 pandemic, episodic transmission events can have severe consequences for human health. This study reveals that the major human variant of the antiviral protein MxB inhibits the human pathogen HSV-1, whereas human minor variants and orthologous MxB genes from even closely related primates do not. Thus, in contrast to the many antagonistic virus-host interactions in which the virus is successful in thwarting the defense systems of their native hosts, in this case the human gene appears to be at least temporarily winning at this interface of the primate-herpesviral evolutionary arms race. Our findings further show that a polymorphism at amino acid 83 in a small fraction of the human population is sufficient to abrogate MxB's ability to inhibit HSV-1, which could have important implications for human susceptibility to HSV-1 pathogenesis.
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Affiliation(s)
- Avraham Bayer
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Stephanie J. Child
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Harmit S. Malik
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Adam P. Geballe
- Division of Human Biology, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Clinical Research Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
- Departments of Medicine and Microbiology, University of Washington, Seattle WA, USA
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12
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Betancor G. You Shall Not Pass: MX2 Proteins Are Versatile Viral Inhibitors. Vaccines (Basel) 2023; 11:vaccines11050930. [PMID: 37243034 DOI: 10.3390/vaccines11050930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Myxovirus resistance (MX) proteins are pivotal players in the innate immune response to viral infections. Less than 10 years ago, three independent groups simultaneously showed that human MX2 is an interferon (IFN)-stimulated gene (ISG) with potent anti-human immunodeficiency virus 1 (HIV-1) activity. Thenceforth, multiple research works have been published highlighting the ability of MX2 to inhibit RNA and DNA viruses. These growing bodies of evidence have identified some of the key determinants regulating its antiviral activity. Therefore, the importance of the protein amino-terminal domain, the oligomerization state, or the ability to interact with viral components is now well recognized. Nonetheless, there are still several unknown aspects of MX2 antiviral activity asking for further research, such as the role of cellular localization or the effect of post-translational modifications. This work aims to provide a comprehensive review of our current knowledge on the molecular determinants governing the antiviral activity of this versatile ISG, using human MX2 and HIV-1 inhibition as a reference, but drawing parallelisms and noting divergent mechanisms with other proteins and viruses when necessary.
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Affiliation(s)
- Gilberto Betancor
- Instituto Universitario de Investigaciones Biomédicas y Sanitarias (IUIBS), Universidad de Las Palmas de Gran Canaria, 35016 Las Palmas de Gran Canaria, Canary Islands, Spain
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13
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Ohkura S, Horie M, Shimizu M, Nakagawa S, Osanai H, Miyagawa Y, Morita R. Characterization of Megabat-Favored, CA-Dependent Susceptibility to Retrovirus Infection. J Virol 2023; 97:e0180322. [PMID: 36779757 PMCID: PMC10062173 DOI: 10.1128/jvi.01803-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 12/21/2022] [Indexed: 02/14/2023] Open
Abstract
The isolation of the Koala retrovirus-like virus from Australian megabats and the identification of endogenous retroviruses in the bat genome have raised questions on bat susceptibility to retroviruses in general. To answer this, we studied the susceptibility of 12 cell lines from 11 bat species to four well-studied retroviruses (human and simian immunodeficiency viruses [HIV and SIV] and murine leukemia viruses [B- and N-MLV]). Systematic comparison of retroviral susceptibility among bats revealed that megabat cell lines were overall less susceptible to the four retroviruses than microbat cell lines, particularly to HIV-1 infection, whereas lineage-specific differences were observed for MLV susceptibility. Quantitative PCR of reverse transcription (RT) products, infection in heterokaryon cells, and point mutation analysis of the capsid (CA) revealed that (i) HIV-1 and MLV replication were blocked at the nuclear transport of the pre-integration complexes and before and/or during RT, respectively, and (ii) the observed lineage-specific restriction can be attributed to a dominant cellular factor constrained by specific positions in CA. Investigation of bat homologs of the three previously reported post-entry restriction factors constrained by the same residues in CA, tripartite motif-protein 5α (TRIM5α), myxovirus resistance 2/B (Mx2/MxB), and carboxy terminus-truncated cleavage and polyadenylation factor 6 (CPSF6-358), demonstrated poor anti-HIV-1 activity in megabat cells, whereas megabat TRIM5α restricted MLV infection, suggesting that the major known CA-dependent restriction factors were not dominant in the observed lineage-specific susceptibility to HIV-1 in bat cells. Therefore, HIV-1 susceptibility of megabat cells may be determined in a manner distinct from that of primate cells. IMPORTANCE Recent studies have demonstrated the circulation of gammaretroviruses among megabats in Australia and the bats' resistance to HIV-1 infection; however, the origins of these viruses in megabats and the contribution of bats to retrovirus spread to other mammalian species remains unclear. To determine the intrinsic susceptibility of bat cells to HIV-1 infection, we investigated 12 cell lines isolated from 11 bat species. We report that lineage-specific retrovirus restriction in the bat cell lines can be attributed to CA-dependent factors. However, in the megabat cell lines examined, factors known to bind capsid and block infection in primate cell culture, including homologs of TRIM5α, Mx2/MxB, and CPSF6, failed to exhibit significant anti-HIV-1 activities. These results suggested that the HIV-1 susceptibility of megabat cells occurs in a manner distinct from that of primate cells, where cellular factors, other than major known CA-dependent restriction factors, with lineage-specific functions could recognize retroviral proteins in megabats.
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Affiliation(s)
- Sadayuki Ohkura
- Department of Microbiology and Immunology, Nippon Medical School, Tokyo, Japan
| | - Masayuki Horie
- Graduate School of Veterinary Science, Osaka Metropolitan University, Osaka, Japan
- Osaka International Research Center for Infectious Diseases, Osaka Metropolitan University, Osaka, Japan
| | - Masumi Shimizu
- Department of Microbiology and Immunology, Nippon Medical School, Tokyo, Japan
| | - So Nakagawa
- Department of Molecular Life Science, Tokai University School of Medicine, Kanagawa, Japan
| | - Haruka Osanai
- Department of Medicine, Nippon Medical School, Tokyo, Japan
| | - Yoshitaka Miyagawa
- Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan
| | - Rimpei Morita
- Department of Microbiology and Immunology, Nippon Medical School, Tokyo, Japan
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14
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McKellar J, Arnaud-Arnould M, Chaloin L, Tauziet M, Arpin-André C, Pourcelot O, Blaise M, Moncorgé O, Goujon C. An evolutionarily conserved N-terminal leucine is essential for MX1 GTPase antiviral activity against different families of RNA viruses. J Biol Chem 2023; 299:102747. [PMID: 36436557 PMCID: PMC9808005 DOI: 10.1016/j.jbc.2022.102747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/27/2022] Open
Abstract
Myxovirus resistance protein 1 (MX1) and MX2 are homologous, dynamin-like large GTPases, induced upon interferon exposure. Human MX1 (HsMX1) is known to inhibit many viruses, including influenza A virus, by likely acting at various steps of their life cycles. Despite decades of studies, the mechanism(s) of action with which MX1 proteins manage to inhibit target viruses is not fully understood. MX1 proteins are mechano-enzymes and share a similar organization to dynamin, with a GTPase domain and a carboxy-terminal stalk domain, connected by a bundle signaling element. These three elements are known to be essential for antiviral activity. HsMX1 has two unstructured regions, the L4 loop, also essential for antiviral activity, and a short amino (N)-terminal region, which greatly varies between MX1 proteins of different species. The role of this N-terminal domain in antiviral activity is not known. Herein, using mutagenesis, imaging, and biochemical approaches, we demonstrate that the N-terminal domain of HsMX1 is essential for antiviral activity against influenza A virus, Vesicular Stomatitis Virus, and La Crosse virus. Furthermore, we pinpoint a highly conserved leucine within this region, which is absolutely crucial for human, mouse, and bat MX1 protein antiviral activity. Importantly, mutation of this leucine does not compromise GTPase activity or oligomerization capabilities but does modify MX1 protein subcellular localization. The discovery of this essential and highly conserved residue defines this region as key for antiviral activity and may reveal insights as to the mechanism(s) of action of MX1 proteins.
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Affiliation(s)
- Joe McKellar
- IRIM, CNRS, Montpellier University, Montpellier, France
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15
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MX2 Viral Substrate Breadth and Inhibitory Activity Are Regulated by Protein Phosphorylation. mBio 2022; 13:e0171422. [PMID: 35880880 PMCID: PMC9426416 DOI: 10.1128/mbio.01714-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type-1 (HIV-1) infection is potently inhibited by human myxovirus resistance 2 (MX2/MxB), which binds to the viral capsid and blocks the nuclear import of viral DNA. We have recently shown that phosphorylation is a key regulator of MX2 antiviral activity, with phosphorylation of serine residues at positions 14, 17, and 18 repressing MX2 function. Here, we extend the study of MX2 posttranslational modifications and identify serine and threonine phosphorylation in all domains of MX2. By substituting these residues with aspartic acid or alanine, hence mimicking the presence or absence of a phosphate group, respectively, we identified key positions that control MX2 antiviral activity. Aspartic acid substitutions of residues Ser306 or Thr334 and alanine substitutions of Thr343 yielded proteins with substantially reduced antiviral activity, whereas the presence of aspartic acid at positions Ser28, Thr151, or Thr343 resulted in enhanced activity: referred to as hypermorphic mutants. In some cases, these hypermorphic mutations, particularly when paired with other MX2 mutations (e.g., S28D/T151D or T151D/T343A) acquired the capacity to inhibit HIV-1 capsid mutants known to be insensitive to wild-type MX2, such as P90A or T210K, as well as MX2-resistant retroviruses such as equine infectious anemia virus (EIAV) and murine leukemia virus (MLV). This work highlights the complexity and importance of MX2 phosphorylation in the regulation of antiviral activity and in the selection of susceptible viral substrates.
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16
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Serrero MC, Girault V, Weigang S, Greco TM, Ramos-Nascimento A, Anderson F, Piras A, Hickford Martinez A, Hertzog J, Binz A, Pohlmann A, Prank U, Rehwinkel J, Bauerfeind R, Cristea IM, Pichlmair A, Kochs G, Sodeik B. The interferon-inducible GTPase MxB promotes capsid disassembly and genome release of herpesviruses. eLife 2022; 11:e76804. [PMID: 35475759 PMCID: PMC9150894 DOI: 10.7554/elife.76804] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 04/22/2022] [Indexed: 11/18/2022] Open
Abstract
Host proteins sense viral products and induce defence mechanisms, particularly in immune cells. Using cell-free assays and quantitative mass spectrometry, we determined the interactome of capsid-host protein complexes of herpes simplex virus and identified the large dynamin-like GTPase myxovirus resistance protein B (MxB) as an interferon-inducible protein interacting with capsids. Electron microscopy analyses showed that cytosols containing MxB had the remarkable capability to disassemble the icosahedral capsids of herpes simplex viruses and varicella zoster virus into flat sheets of connected triangular faces. In contrast, capsids remained intact in cytosols with MxB mutants unable to hydrolyse GTP or to dimerize. Our data suggest that MxB senses herpesviral capsids, mediates their disassembly, and thereby restricts the efficiency of nuclear targeting of incoming capsids and/or the assembly of progeny capsids. The resulting premature release of viral genomes from capsids may enhance the activation of DNA sensors, and thereby amplify the innate immune responses.
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Affiliation(s)
- Manutea C Serrero
- Institute of Virology, Hannover Medical SchoolHannoverGermany
- RESIST - Cluster of Excellence, Hannover Medical SchoolHannoverGermany
| | | | - Sebastian Weigang
- Institute of Virology, Freiburg University Medical Center, University of FreiburgFreiburgGermany
| | - Todd M Greco
- Department of Molecular Biology, Princeton UniversityPrincetonUnited States
| | | | - Fenja Anderson
- Institute of Virology, Hannover Medical SchoolHannoverGermany
| | - Antonio Piras
- Institute of Virology, Technical University MunichMunichGermany
| | | | - Jonny Hertzog
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of OxfordOxfordUnited Kingdom
| | - Anne Binz
- Institute of Virology, Hannover Medical SchoolHannoverGermany
- RESIST - Cluster of Excellence, Hannover Medical SchoolHannoverGermany
- German Center for Infection Research (DZIF), Hannover-Braunschweig Partner SiteHannoverGermany
| | - Anja Pohlmann
- Institute of Virology, Hannover Medical SchoolHannoverGermany
- RESIST - Cluster of Excellence, Hannover Medical SchoolHannoverGermany
- German Center for Infection Research (DZIF), Hannover-Braunschweig Partner SiteHannoverGermany
| | - Ute Prank
- Institute of Virology, Hannover Medical SchoolHannoverGermany
| | - Jan Rehwinkel
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of OxfordOxfordUnited Kingdom
| | - Rudolf Bauerfeind
- Research Core Unit Laser Microscopy, Hannover Medical SchoolHannoverGermany
| | - Ileana M Cristea
- Department of Molecular Biology, Princeton UniversityPrincetonUnited States
| | - Andreas Pichlmair
- Institute of Virology, Technical University MunichMunichGermany
- German Center for Infection Research (DZIF), Munich Partner siteMunichGermany
| | - Georg Kochs
- Institute of Virology, Freiburg University Medical Center, University of FreiburgFreiburgGermany
| | - Beate Sodeik
- Institute of Virology, Hannover Medical SchoolHannoverGermany
- RESIST - Cluster of Excellence, Hannover Medical SchoolHannoverGermany
- German Center for Infection Research (DZIF), Hannover-Braunschweig Partner SiteHannoverGermany
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17
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Li Q, An N, Yin X, Zhang R, Shao H, Yi D, Cen S. MxB Disrupts Hepatitis C Virus NS5A–CypA Complex: Insights From a Combined Theoretical and Experimental Approach. Front Microbiol 2022; 13:849084. [PMID: 35369502 PMCID: PMC8969595 DOI: 10.3389/fmicb.2022.849084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 02/08/2022] [Indexed: 11/13/2022] Open
Abstract
The human myxovirus resistance B (MxB) protein is an interferon-induced restriction factor that fights a wide range of viruses. We previously demonstrated that MxB binds to hepatitis C virus (HCV)-encoded non-structural protein 5A (NS5A) and inhibits HCV infection by impairing the formation of cyclophilin A (CypA)–NS5A complex. However, the molecular details about how the presence of MxB diminishes the binding of NS5A to CypA remain uncovered. In this study, through molecular dynamic simulations and biochemical assays, we characterized that MxB binds to NS5A domain I through its N-terminal and GTPase domains. Specifically, amino acids (aa.) 189–191 and aa. 330–334 within MxB, together with NS5A residues aa. 71–73, are crucial for MxB–NS5A interaction. Furthermore, we predicted the CypA:NS5A and CypA:NS5A:MxB complexes and calculated the per-residue energy decomposition for identified key residues of the CypA–NS5A interface. A 28% decrease in CypA–NS5A binding affinity was observed in the presence of MxB, suggesting a weakened CypA–NS5A association upon binding of MxB to NS5A, which may contribute to the MxB-mediated inhibitory effect on the formation of CypA–NS5A complex. This work provides information for the antiviral mechanism of MxB and may facilitate the discovery of new strategies to combat CypA-dependent viruses.
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Affiliation(s)
- Quanjie Li
- Department of Immunology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, China
| | - Ni An
- Department of Immunology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiao Yin
- Department of Immunology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, China
- Center for Drug Evaluation, National Medical Products Administration, Beijing, China
| | - Ruixin Zhang
- Department of Immunology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, China
| | - Huihan Shao
- Department of Immunology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, China
| | - Dongrong Yi
- Department of Immunology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, China
- *Correspondence: Dongrong Yi,
| | - Shan Cen
- Department of Immunology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, China
- Shan Cen,
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18
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Saito A, Yamashita M. HIV-1 capsid variability: viral exploitation and evasion of capsid-binding molecules. Retrovirology 2021; 18:32. [PMID: 34702294 PMCID: PMC8549334 DOI: 10.1186/s12977-021-00577-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/13/2021] [Indexed: 11/17/2022] Open
Abstract
The HIV-1 capsid, a conical shell encasing viral nucleoprotein complexes, is involved in multiple post-entry processes during viral replication. Many host factors can directly bind to the HIV-1 capsid protein (CA) and either promote or prevent HIV-1 infection. The viral capsid is currently being explored as a novel target for therapeutic interventions. In the past few decades, significant progress has been made in our understanding of the capsid–host interactions and mechanisms of action of capsid-targeting antivirals. At the same time, a large number of different viral capsids, which derive from many HIV-1 mutants, naturally occurring variants, or diverse lentiviruses, have been characterized for their interactions with capsid-binding molecules in great detail utilizing various experimental techniques. This review provides an overview of how sequence variation in CA influences phenotypic properties of HIV-1. We will focus on sequence differences that alter capsid–host interactions and give a brief account of drug resistant mutations in CA and their mutational effects on viral phenotypes. Increased knowledge of the sequence-function relationship of CA helps us deepen our understanding of the adaptive potential of the viral capsid.
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Affiliation(s)
- Akatsuki Saito
- Department of Veterinary Medicine, Faculty of Agriculture, University of Miyazaki, Miyazaki, Miyazaki, Japan.,Center for Animal Disease Control, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Masahiro Yamashita
- Aaron Diamond AIDS Research Center, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.
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19
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The journey of herpesvirus capsids and genomes to the host cell nucleus. Curr Opin Virol 2021; 50:147-158. [PMID: 34464845 DOI: 10.1016/j.coviro.2021.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 01/04/2023]
Abstract
Starting a herpesviral infection is a steeplechase across membranes, cytosol, and nuclear envelopes and against antiviral defence mechanisms. Here, we highlight recent insights on capsid stabilization at the portals during assembly, early capsid-host interactions ensuring nuclear targeting of incoming capsids, and genome uncoating. After fusion with a host membrane, incoming capsids recruit microtubule motors for traveling to the centrosome, and by unknown mechanisms get forward towards the nucleus. The interaction of capsid-associated tegument proteins with nucleoporins orients the capsid portal towards the nuclear pore, and presumably after removal of the portal caps the genomes that have been packaged under pressure can be injected into the nucleoplasm for transcription and replication. Some cell types disarm the incoming capsids or silence the incoming genomes to reduce the likelihood of infection.
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20
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Hadpech S, Moonmuang S, Chupradit K, Yasamut U, Tayapiwatana C. Updating on Roles of HIV Intrinsic Factors: A Review of Their Antiviral Mechanisms and Emerging Functions. Intervirology 2021; 65:67-79. [PMID: 34464956 DOI: 10.1159/000519241] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 08/24/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Host restriction factors are cellular proteins that inhibit specific steps of the viral life cycle. Since the 1970s, several new factors have been identified, including human immunodeficiency virus-1 (HIV-1) replication restriction. Evidence accumulated in the last decade has substantially broadened our understanding of the molecular mechanisms utilized to abrogate the HIV-1 life cycle. SUMMARY In this review, we focus on the interaction between host restriction factors participating in the early phase of HIV-1 infection, particularly CA-targeting proteins. Host factors involved in the late phase of the replication cycle, such as viral assembly and egress factors, are also described. Additionally, current reports on well-known antiviral intrinsic factors, as well as other viral restriction factors with their emerging roles, are included. CONCLUSION A comprehensive understanding of the interactions between viruses and hosts is expected to provide insight into the design of novel HIV-1 therapeutic interventions.
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Affiliation(s)
- Sudarat Hadpech
- Division of Pharmacology and Biopharmacy, Faculty of Pharmaceutical Sciences, Burapha University, Chon Buri, Thailand
| | - Sutpirat Moonmuang
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Center of Biomolecular Therapy and Diagnostic, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Koollawat Chupradit
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Center of Biomolecular Therapy and Diagnostic, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Siriraj Center for Regenerative Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Umpa Yasamut
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Center of Biomolecular Therapy and Diagnostic, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Center of Innovative Immunodiagnostic Development, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Chatchai Tayapiwatana
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Center of Biomolecular Therapy and Diagnostic, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.,Center of Innovative Immunodiagnostic Development, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
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21
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Betancor G, Jimenez-Guardeño JM, Lynham S, Antrobus R, Khan H, Sobala A, Dicks MDJ, Malim MH. MX2-mediated innate immunity against HIV-1 is regulated by serine phosphorylation. Nat Microbiol 2021; 6:1031-1042. [PMID: 34282309 PMCID: PMC7611661 DOI: 10.1038/s41564-021-00937-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/17/2021] [Indexed: 01/24/2023]
Abstract
The antiviral cytokine interferon activates expression of interferon-stimulated genes to establish an antiviral state. Myxovirus resistance 2 (MX2, also known as MxB) is an interferon-stimulated gene that inhibits the nuclear import of HIV-1 and interacts with the viral capsid and cellular nuclear transport machinery. Here, we identified the myosin light chain phosphatase (MLCP) subunits myosin phosphatase target subunit 1 (MYPT1) and protein phosphatase 1 catalytic subunit-β (PPP1CB) as positively-acting regulators of MX2, interacting with its amino-terminal domain. We demonstrated that serine phosphorylation of the N-terminal domain at positions 14, 17 and 18 suppresses MX2 antiviral function, prevents interactions with the HIV-1 capsid and nuclear transport factors, and is reversed by MLCP. Notably, serine phosphorylation of the N-terminal domain also impedes MX2-mediated inhibition of nuclear import of cellular karyophilic cargo. We also found that interferon treatment reduces levels of phosphorylation at these serine residues and outline a homeostatic regulatory mechanism in which repression of MX2 by phosphorylation, together with MLCP-mediated dephosphorylation, balances the deleterious effects of MX2 on normal cell function with innate immunity against HIV-1.
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Affiliation(s)
- Gilberto Betancor
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK.
| | - Jose M Jimenez-Guardeño
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Steven Lynham
- Centre of Excellence for Mass Spectrometry, The James Black Centre, King's College London, London, UK
| | - Robin Antrobus
- Cambridge Institute for Medical Research, Department of Medicine, University of Cambridge, Cambridge, UK
| | - Hataf Khan
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Andrew Sobala
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Matthew D J Dicks
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Michael H Malim
- Department of Infectious Diseases, School of Immunology and Microbial Sciences, King's College London, London, UK.
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22
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Chai K, Wang Z, Pan Q, Tan J, Qiao W, Liang C. Effect of Different Nuclear Localization Signals on the Subcellular Localization and Anti-HIV-1 Function of the MxB Protein. Front Microbiol 2021; 12:675201. [PMID: 34093497 PMCID: PMC8173038 DOI: 10.3389/fmicb.2021.675201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/26/2021] [Indexed: 12/24/2022] Open
Abstract
Interferon exerts its antiviral activity by stimulating the expression of antiviral proteins. These interferon stimulate genes (ISGs) often target a group of viruses with unique molecular mechanisms. One such ISG is myxovirus resistance B (MxB) that has been reported to inhibit human immunodeficiency virus type 1 (HIV-1) by targeting viral capsid and impairing nuclear import of viral DNA. The antiviral specificity of MxB is determined by its N-terminal 25 amino acids sequence which has the nuclear localization activity, therefore functions as a nuclear localization signal (NLS). In this study, we report that the bipartite NLS, but not the classic NLS, the PY-NLS, nor the arginine-rich NLS, when used to replace the N-terminal sequence of MxB, drastically suppress HIV-1 gene expression and virus production, thus creates a new anti-HIV-1 mechanism. MxB preserves its anti-HIV-1 activity when its N-terminal sequence is replaced by the arginine-rich NLS. Interestingly, the arginine-rich NLS allows MxB to inhibit HIV-1 CA mutants that are otherwise resistant to wild type MxB, which suggests sequence specific targeting of viral capsid. Together, these data implicate that it is not the nuclear import function itself, but rather the sequence and the mechanism of action of the NLS which define the antiviral property of MxB.
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Affiliation(s)
- Keli Chai
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China.,Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Zhen Wang
- Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Qinghua Pan
- Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada
| | - Juan Tan
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Wentao Qiao
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Chen Liang
- Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada.,Department of Medicine, McGill University, Montreal, QC, Canada
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23
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Chelbi-Alix MK, Thibault P. Crosstalk Between SUMO and Ubiquitin-Like Proteins: Implication for Antiviral Defense. Front Cell Dev Biol 2021; 9:671067. [PMID: 33968942 PMCID: PMC8097047 DOI: 10.3389/fcell.2021.671067] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/29/2021] [Indexed: 12/19/2022] Open
Abstract
Interferon (IFN) is a crucial first line of defense against viral infection. This cytokine induces the expression of several IFN-Stimulated Genes (ISGs), some of which act as restriction factors. Upon IFN stimulation, cells also express ISG15 and SUMO, two key ubiquitin-like (Ubl) modifiers that play important roles in the antiviral response. IFN itself increases the global cellular SUMOylation in a PML-dependent manner. Mass spectrometry-based proteomics enables the large-scale identification of Ubl protein conjugates to determine the sites of modification and the quantitative changes in protein abundance. Importantly, a key difference amongst SUMO paralogs is the ability of SUMO2/3 to form poly-SUMO chains that recruit SUMO ubiquitin ligases such RING finger protein RNF4 and RNF111, thus resulting in the proteasomal degradation of conjugated substrates. Crosstalk between poly-SUMOylation and ISG15 has been reported recently, where increased poly-SUMOylation in response to IFN enhances IFN-induced ISGylation, stabilizes several ISG products in a TRIM25-dependent fashion, and results in enhanced IFN-induced antiviral activities. This contribution will highlight the relevance of the global SUMO proteome and the crosstalk between SUMO, ubiquitin and ISG15 in controlling both the stability and function of specific restriction factors that mediate IFN antiviral defense.
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Affiliation(s)
| | - Pierre Thibault
- Institute for Research in Immunology and Cancer, Montréal, QC, Canada
- Department of Chemistry, University of Montreal, Montréal, QC, Canada
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24
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Wang Z, Chai K, Liu Q, Yi DR, Pan Q, Huang Y, Tan J, Qiao W, Guo F, Cen S, Liang C. HIV-1 resists MxB inhibition of viral Rev protein. Emerg Microbes Infect 2021; 9:2030-2045. [PMID: 32873191 PMCID: PMC7534208 DOI: 10.1080/22221751.2020.1818633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The interferon-inducible myxovirus resistance B (MxB) protein has been reported to inhibit HIV-1 and herpesviruses by blocking the nuclear import of viral DNA. Here, we report a new antiviral mechanism in which MxB restricts the nuclear import of HIV-1 regulatory protein Rev, and as a result, diminishes Rev-dependent expression of HIV-1 Gag protein. Specifically, MxB disrupts the interaction of Rev with the nuclear transport receptor, transportin 1 (TNPO1). Supporting this, the TNPO1-independent Rev variants become less restricted by MxB. In addition, HIV-1 can overcome this inhibition by MxB through increasing the expression of multiply spliced viral RNA and hence Rev protein. Therefore, MxB exerts its anti-HIV-1 function through interfering with the nuclear import of both viral DNA and viral Rev protein.
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Affiliation(s)
- Zhen Wang
- Lady Davis Institute, Jewish General Hospital, Montreal, Canada.,Department of Medicine, McGill University, Montreal, Canada
| | - Keli Chai
- Lady Davis Institute, Jewish General Hospital, Montreal, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, Canada.,College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Qian Liu
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing, People's Republic of China
| | - Dong-Rong Yi
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing, People's Republic of China
| | - Qinghua Pan
- Lady Davis Institute, Jewish General Hospital, Montreal, Canada
| | - Yu Huang
- Institute of Pathogen Biology, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, People's Republic of China
| | - Juan Tan
- College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Wentao Qiao
- College of Life Sciences, Nankai University, Tianjin, People's Republic of China
| | - Fei Guo
- Institute of Pathogen Biology, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, People's Republic of China
| | - Shan Cen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing, People's Republic of China
| | - Chen Liang
- Lady Davis Institute, Jewish General Hospital, Montreal, Canada.,Department of Medicine, McGill University, Montreal, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, Canada
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25
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McKellar J, Rebendenne A, Wencker M, Moncorgé O, Goujon C. Mammalian and Avian Host Cell Influenza A Restriction Factors. Viruses 2021; 13:522. [PMID: 33810083 PMCID: PMC8005160 DOI: 10.3390/v13030522] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 12/27/2022] Open
Abstract
The threat of a new influenza pandemic is real. With past pandemics claiming millions of lives, finding new ways to combat this virus is essential. Host cells have developed a multi-modular system to detect incoming pathogens, a phenomenon called sensing. The signaling cascade triggered by sensing subsequently induces protection for themselves and their surrounding neighbors, termed interferon (IFN) response. This response induces the upregulation of hundreds of interferon-stimulated genes (ISGs), including antiviral effectors, establishing an antiviral state. As well as the antiviral proteins induced through the IFN system, cells also possess a so-called intrinsic immunity, constituted of antiviral proteins that are constitutively expressed, creating a first barrier preceding the induction of the interferon system. All these combined antiviral effectors inhibit the virus at various stages of the viral lifecycle, using a wide array of mechanisms. Here, we provide a review of mammalian and avian influenza A restriction factors, detailing their mechanism of action and in vivo relevance, when known. Understanding their mode of action might help pave the way for the development of new influenza treatments, which are absolutely required if we want to be prepared to face a new pandemic.
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Affiliation(s)
- Joe McKellar
- Institut de Recherche en Infectiologie de Montpellier, CNRS, Université de Montpellier, CEDEX 5, 34293 Montpellier, France; (J.M.); (A.R.)
| | - Antoine Rebendenne
- Institut de Recherche en Infectiologie de Montpellier, CNRS, Université de Montpellier, CEDEX 5, 34293 Montpellier, France; (J.M.); (A.R.)
| | - Mélanie Wencker
- Centre International de Recherche en Infectiologie, INSERM/CNRS/UCBL1/ENS de Lyon, 69007 Lyon, France;
| | - Olivier Moncorgé
- Institut de Recherche en Infectiologie de Montpellier, CNRS, Université de Montpellier, CEDEX 5, 34293 Montpellier, France; (J.M.); (A.R.)
| | - Caroline Goujon
- Institut de Recherche en Infectiologie de Montpellier, CNRS, Université de Montpellier, CEDEX 5, 34293 Montpellier, France; (J.M.); (A.R.)
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26
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Sehgal PB, Yuan H, Scott MF, Deng Y, Liang FX, Mackiewicz A. Murine GFP-Mx1 forms nuclear condensates and associates with cytoplasmic intermediate filaments: Novel antiviral activity against VSV. J Biol Chem 2020; 295:18023-18035. [PMID: 33077519 PMCID: PMC7939456 DOI: 10.1074/jbc.ra120.015661] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/30/2020] [Indexed: 11/06/2022] Open
Abstract
Type I and III interferons induce expression of the "myxovirus resistance proteins" MxA in human cells and its ortholog Mx1 in murine cells. Human MxA forms cytoplasmic structures, whereas murine Mx1 forms nuclear bodies. Whereas both HuMxA and MuMx1 are antiviral toward influenza A virus (FLUAV) (an orthomyxovirus), only HuMxA is considered antiviral toward vesicular stomatitis virus (VSV) (a rhabdovirus). We previously reported that the cytoplasmic human GFP-MxA structures were phase-separated membraneless organelles ("biomolecular condensates"). In the present study, we investigated whether nuclear murine Mx1 structures might also represent phase-separated biomolecular condensates. The transient expression of murine GFP-Mx1 in human Huh7 hepatoma, human Mich-2H6 melanoma, and murine NIH 3T3 cells led to the appearance of Mx1 nuclear bodies. These GFP-MuMx1 nuclear bodies were rapidly disassembled by exposing cells to 1,6-hexanediol (5%, w/v), or to hypotonic buffer (40-50 mosm), consistent with properties of membraneless phase-separated condensates. Fluorescence recovery after photobleaching (FRAP) assays revealed that the GFP-MuMx1 nuclear bodies upon photobleaching showed a slow partial recovery (mobile fraction: ∼18%) suggestive of a gel-like consistency. Surprisingly, expression of GFP-MuMx1 in Huh7 cells also led to the appearance of GFP-MuMx1 in 20-30% of transfected cells in a novel cytoplasmic giantin-based intermediate filament meshwork and in cytoplasmic bodies. Remarkably, Huh7 cells with cytoplasmic murine GFP-MuMx1 filaments, but not those with only nuclear bodies, showed antiviral activity toward VSV. Thus, GFP-MuMx1 nuclear bodies comprised phase-separated condensates. Unexpectedly, GFP-MuMx1 in Huh7 cells also associated with cytoplasmic giantin-based intermediate filaments, and such cells showed antiviral activity toward VSV.
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Affiliation(s)
- Pravin B Sehgal
- Departments of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA; Department of Medicine, New York Medical College, Valhalla, New York, USA.
| | - Huijuan Yuan
- Departments of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA
| | - Mia F Scott
- Departments of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA
| | - Yan Deng
- Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, New York, USA
| | - Feng-Xia Liang
- Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, New York, USA
| | - Andrzej Mackiewicz
- Department of Medical Biotechnology, University School of Medical Sciences, Poznań, Poland; Department of Diagnostics and Immunology of Cancer, Greater Poland Cancer Center, Poznań, Poland
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27
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Retroviral Restriction Factors and Their Viral Targets: Restriction Strategies and Evolutionary Adaptations. Microorganisms 2020; 8:microorganisms8121965. [PMID: 33322320 PMCID: PMC7764263 DOI: 10.3390/microorganisms8121965] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/30/2020] [Accepted: 12/08/2020] [Indexed: 12/17/2022] Open
Abstract
The evolutionary conflict between retroviruses and their vertebrate hosts over millions of years has led to the emergence of cellular innate immune proteins termed restriction factors as well as their viral antagonists. Evidence accumulated in the last two decades has substantially increased our understanding of the elaborate mechanisms utilized by these restriction factors to inhibit retroviral replication, mechanisms that either directly block viral proteins or interfere with the cellular pathways hijacked by the viruses. Analyses of these complex interactions describe patterns of accelerated evolution for these restriction factors as well as the acquisition and evolution of their virus-encoded antagonists. Evidence is also mounting that many restriction factors identified for their inhibition of specific retroviruses have broader antiviral activity against additional retroviruses as well as against other viruses, and that exposure to these multiple virus challenges has shaped their adaptive evolution. In this review, we provide an overview of the restriction factors that interfere with different steps of the retroviral life cycle, describing their mechanisms of action, adaptive evolution, viral targets and the viral antagonists that evolved to counter these factors.
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28
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Subcellular Localization of MxB Determines Its Antiviral Potential against Influenza A Virus. J Virol 2020; 94:JVI.00125-20. [PMID: 32907985 PMCID: PMC7592211 DOI: 10.1128/jvi.00125-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 09/01/2020] [Indexed: 11/20/2022] Open
Abstract
The interferon system plays a pivotal role in the defense against viral infections. The dynamin-related Mx proteins form a small family of interferon-induced effector proteins with distinct antiviral specificities and subcellular localizations. So far, it is not clear whether the different virus specificities of Mx proteins are the result of distinct mechanisms of action or are due rather to their different subcellular localization. We show here that the human MxB protein, normally localized to the outer membrane of the cell nucleus, acquires antiviral activity against IAV when redirected to the nucleus or cytoplasm, subcellular sites where other members of the Mx protein family efficiently interfere with IAV replication. Our findings thus strongly suggest that Mx proteins act primarily through a common mechanism and that their viral specificity is at least in part determined by their individual subcellular localization. Mx proteins are interferon (IFN) type I (α/β)- and type III (λ)-induced effector proteins with intrinsic antiviral activity. Mammalian Mx proteins show different subcellular localizations and distinct yet partially overlapping viral specificities. However, the precise mechanism(s) of antiviral action are still unresolved. Human MxA accumulates in the cytoplasm and inhibits a wide variety of RNA and DNA viruses, among them influenza A virus (IAV). In contrast, MxB, the second human Mx protein, localizes via its amino (N) terminus to the outer nuclear membrane at or near nuclear pores and inhibits the nuclear import of incoming human immunodeficiency viruses (HIV) and herpesviruses, but not that of IAV. Here, we evaluated whether the antiviral specificity of MxB is determined by its subcellular localization. For this purpose, we redirected MxB to the nucleus or cytoplasm by either attaching a nuclear localization signal to its N terminus or by exchanging the N terminus of MxB with that of MxA. Interestingly, ectopic expression of these MxB variants in the nucleus or in the cytoplasm rendered the host cells resistant to IAV, revealing that the capacity of MxB to block IAV replication critically depends on the site where the protein accumulates in the infected cell. Furthermore, coimmunoprecipitation (co-IP) assays demonstrated that MxB physically interacted with the nucleoprotein (NP) of IAV. Taken together, the data indicate that the subcellular localization of the MxB protein plays a pivotal role in determining its antiviral specificity. IMPORTANCE The interferon system plays a pivotal role in the defense against viral infections. The dynamin-related Mx proteins form a small family of interferon-induced effector proteins with distinct antiviral specificities and subcellular localizations. So far, it is not clear whether the different virus specificities of Mx proteins are the result of distinct mechanisms of action or are due rather to their different subcellular localization. We show here that the human MxB protein, normally localized to the outer membrane of the cell nucleus, acquires antiviral activity against IAV when redirected to the nucleus or cytoplasm, subcellular sites where other members of the Mx protein family efficiently interfere with IAV replication. Our findings thus strongly suggest that Mx proteins act primarily through a common mechanism and that their viral specificity is at least in part determined by their individual subcellular localization.
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29
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Betancor G, Dicks MDJ, Jimenez-Guardeño JM, Ali NH, Apolonia L, Malim MH. The GTPase Domain of MX2 Interacts with the HIV-1 Capsid, Enabling Its Short Isoform to Moderate Antiviral Restriction. Cell Rep 2020; 29:1923-1933.e3. [PMID: 31722207 PMCID: PMC7391006 DOI: 10.1016/j.celrep.2019.10.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/18/2019] [Accepted: 10/02/2019] [Indexed: 01/27/2023] Open
Abstract
Myxovirus resistance 2 (MX2/MXB) is an interferon (IFN)-induced HIV-1 restriction factor that inhibits viral nuclear DNA accumulation. The amino-terminal domain of MX2 binds the viral capsid and is essential for inhibition. Using in vitro assembled Capsid-Nucleocapsid (CANC) complexes as a surrogate for the HIV-1 capsid lattice, we reveal that the GTPase (G) domain of MX2 contains a second, independent capsid-binding site. The importance of this interaction was addressed in competition assays using the naturally occurring non-antiviral short isoform of MX2 that lacks the amino-terminal 25 amino acids. Specifically, these experiments show that the G domain enhances MX2 function, and the foreshortened isoform acts as a functional suppressor of the full-length protein in a G-domain-dependent manner. The interaction of MX2 with its HIV-1 capsid substrate is therefore multi-faceted: there are dual points of contact that, together with protein oligomerization, contribute to the complexity of MX2 regulation. MX2 interacts with the HIV-1 capsid via N-terminal and GTPase (G) domains The G-domain interaction enhances MX2 binding to the viral capsid The MX2 short isoform is not antiviral and binds the capsid through its G domain The MX2 short isoform suppresses the antiviral activity of the long isoform
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Affiliation(s)
- Gilberto Betancor
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King's College London, London SE1 9RT, UK
| | - Matthew D J Dicks
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King's College London, London SE1 9RT, UK
| | - Jose M Jimenez-Guardeño
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King's College London, London SE1 9RT, UK
| | - Nabil H Ali
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King's College London, London SE1 9RT, UK
| | - Luis Apolonia
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King's College London, London SE1 9RT, UK
| | - Michael H Malim
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King's College London, London SE1 9RT, UK.
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30
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Abstract
The COVID-19 pandemic suggests that bat innate immune systems are insufficiently characterized relative to the medical importance of these animals. Retroviruses, e.g., HIV-1, can be severe pathogens when they cross species barriers, and bat restrictions corresponding to retroviruses are comparatively unstudied. Here, we compared the abilities of retroviruses from three genera (Lentivirus, Gammaretrovirus, and Spumavirus) to infect cells of the large fruit-eating bat P. alecto and other mammals. We identified a major, specific postentry restriction to primate lentiviruses. HIV-1 and SIVmac are potently blocked at early life cycle steps, but nonprimate lentiviruses and foamy retroviruses are entirely unrestricted. Despite acting postentry and in a CypA-dependent manner with features reminiscent of antiretroviral factors from other mammals, this restriction was not saturable with virus-like particles and was independent of P. alecto TRIM5, TRIM21, TRIM22, TRIM34, and MX2. These results identify a novel restriction and highlight cyclophilin-capsid interactions as ancient species-specific determinants of retroviral infection. Bats are primary reservoirs for multiple lethal human viruses, such as Ebola, Nipah, Hendra, rabies, severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome-related coronavirus (MERS-CoV), and, most recently, SARS-CoV-2. The innate immune systems of these immensely abundant, anciently diverged mammals remain insufficiently characterized. While bat genomes contain many endogenous retroviral elements indicative of past exogenous infections, little is known about restrictions to extant retroviruses. Here, we describe a major postentry restriction in cells of the yinpterochiropteran bat Pteropus alecto. Primate lentiviruses (HIV-1, SIVmac) were potently blocked at early life cycle steps, with up to 1,000-fold decreases in infectivity. The block was specific, because nonprimate lentiviruses such as equine infectious anemia virus and feline immunodeficiency virus were unimpaired, as were foamy retroviruses. Interspecies heterokaryons demonstrated a dominant block consistent with restriction of incoming viruses. Several features suggested potential TRIM5 (tripartite motif 5) or myxovirus resistance protein 2 (MX2) protein restriction, including postentry action, cyclosporine sensitivity, and reversal by capsid cyclophilin A (CypA) binding loop mutations. Viral nuclear import was significantly reduced, and this deficit was substantially rescued by cyclosporine treatment. However, saturation with HIV-1 virus-like particles did not relieve the restriction at all. P. alecto TRIM5 was inactive against HIV-1 although it blocked the gammaretrovirus N-tropic murine leukemia virus. Despite major divergence in a critical N-terminal motif required for human MX2 activity, P. alecto MX2 had anti-HIV activity. However, this did not quantitatively account for the restriction and was independent of and synergistic with an additional CypA-dependent restriction. These results reveal a novel, specific restriction to primate lentiviruses in the Pteropodidae and advance understanding of bat innate immunity.
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31
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Miles RJ, Kerridge C, Hilditch L, Monit C, Jacques DA, Towers GJ. MxB sensitivity of HIV-1 is determined by a highly variable and dynamic capsid surface. eLife 2020; 9:e56910. [PMID: 32553106 PMCID: PMC7299335 DOI: 10.7554/elife.56910] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/01/2020] [Indexed: 01/20/2023] Open
Abstract
The type one interferon induced restriction factor Myxovirus resistance B (MxB) restricts HIV-1 nuclear entry evidenced by inhibition of 2-LTR but not linear forms of viral DNA. The HIV-1 capsid is the key determinant of MxB sensitivity and cofactor binding defective HIV-1 capsid mutants P90A (defective for cyclophilin A and Nup358 recruitment) and N74D (defective for CPSF6 recruitment) have reduced dependency on nuclear transport associated cofactors, altered integration targeting preferences and are not restricted by MxB expression. This has suggested that nuclear import mechanism may determine MxB sensitivity. Here we have use genetics to separate HIV-1 nuclear import cofactor dependence from MxB sensitivity. We provide evidence that MxB sensitivity depends on HIV-1 capsid conformation, rather than cofactor recruitment. We show that depleting CPSF6 to change nuclear import pathway does not impact MxB sensitivity, but mutants that recapitulate the effect of Cyclophilin A binding on capsid conformation and dynamics strongly impact MxB sensitivity. We demonstrate that HIV-1 primary isolates have different MxB sensitivities due to cytotoxic T lymphocyte (CTL) selected differences in Gag sequence but similar cofactor dependencies. Overall our work demonstrates a complex relationship between cyclophilin dependence and MxB sensitivity likely driven by CTL escape. We propose that cyclophilin binding provides conformational flexibility to HIV-1 capsid facilitating simultaneous evasion of capsid-targeting restriction factors including TRIM5 as well as MxB.
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Affiliation(s)
- Richard J Miles
- Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Claire Kerridge
- Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Laura Hilditch
- Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Christopher Monit
- Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - David A Jacques
- EMBL Australia Node in Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, University of New South WalesSydneyAustralia
| | - Greg J Towers
- Division of Infection and Immunity, University College LondonLondonUnited Kingdom
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32
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Xu F, Zhao F, Zhao X, Zhang D, Liu X, Hu S, Mei S, Fan Z, Huang Y, Sun H, Wei L, Wu C, Li Q, Wang J, Cen S, Liang C, Guo F. Pro-515 of the dynamin-like GTPase MxB contributes to HIV-1 inhibition by regulating MxB oligomerization and binding to HIV-1 capsid. J Biol Chem 2020; 295:6447-6456. [PMID: 32217692 DOI: 10.1074/jbc.ra119.012439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 03/24/2020] [Indexed: 01/19/2023] Open
Abstract
Interferon-regulated myxovirus resistance protein B (MxB) is an interferon-induced GTPase belonging to the dynamin superfamily. It inhibits infection with a wide range of different viruses, including HIV-1, by impairing viral DNA entry into the nucleus. Unlike the related antiviral GTPase MxA, MxB possesses an N-terminal region that contains a nuclear localization signal and is crucial for inhibiting HIV-1. Because MxB previously has been shown to reside in both the nuclear envelope and the cytoplasm, here we used bioinformatics and biochemical approaches to identify a nuclear export signal (NES) responsible for MxB's cytoplasmic location. Using the online computational tool LocNES (Locating Nuclear Export Signals or NESs), we identified five putative NES candidates in MxB and investigated whether their deletion caused nuclear localization of MxB. Our results revealed that none of the five deletion variants relocates to the nucleus, suggesting that these five predicted NES sequences do not confer NES activity. Interestingly, deletion of one sequence, encompassing amino acids 505-527, abrogated the anti-HIV-1 activity of MxB. Further mutation experiments disclosed that amino acids 515-519, and Pro-515 in particular, regulate MxB oligomerization and its binding to HIV-1 capsid, thereby playing an important role in MxB-mediated restriction of HIV-1 infection. In summary, our results indicate that none of the five predicted NES sequences in MxB appears to be required for its nuclear export. Our findings also reveal several residues in MxB, including Pro-515, critical for its oligomerization and anti-HIV-1 function.
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Affiliation(s)
- Fengwen Xu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Fei Zhao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Xiaoxiao Zhao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Di Zhang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Xiaoman Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Siqi Hu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Shan Mei
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Zhangling Fan
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Yu Huang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Hong Sun
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Liang Wei
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Chao Wu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Quanjie Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Jianwei Wang
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Shan Cen
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Chen Liang
- McGill University AIDS Centre, Lady Davis Institute, Jewish General Hospital, Montreal H3T 1E2, Quebec, Canada
| | - Fei Guo
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China .,Center for AIDS Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
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Summers BJ, Digianantonio KM, Smaga SS, Huang PT, Zhou K, Gerber EE, Wang W, Xiong Y. Modular HIV-1 Capsid Assemblies Reveal Diverse Host-Capsid Recognition Mechanisms. Cell Host Microbe 2019; 26:203-216.e6. [PMID: 31415753 DOI: 10.1016/j.chom.2019.07.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 04/21/2019] [Accepted: 07/18/2019] [Indexed: 10/26/2022]
Abstract
The HIV-1 capsid is an ordered protein shell that houses the viral genome during early infection. Its expansive surface consists of an ordered and interfacing array of capsid protein hexamers and pentamers that are recognized by numerous cellular proteins. Many of these proteins recognize specific, assembled capsid interfaces not present in unassembled capsid subunits. We used protein-engineering tools to capture diverse capsid assembly intermediates. We built a repertoire of capsid assemblies (ranging from two to 42 capsid protein molecules) that recreate the various surfaces in infectious capsids. These assemblies reveal unique capsid-targeting mechanisms for each of the anti-HIV factors, TRIMCyp, MxB, and TRIM5α, linked to inhibition of virus uncoating and nuclear entry, as well as the HIV-1 cofactor FEZ1 that facilitates virus intracellular trafficking. This capsid assembly repertoire enables elucidation of capsid recognition modes by known capsid-interacting factors, identification of new capsid-interacting factors, and potentially, development of capsid-targeting therapeutics.
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Affiliation(s)
- Brady J Summers
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | | | - Sarah S Smaga
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Pei-Tzu Huang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Kaifeng Zhou
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Eva E Gerber
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Wei Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA.
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34
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Smaga SS, Xu C, Summers BJ, Digianantonio KM, Perilla JR, Xiong Y. MxB Restricts HIV-1 by Targeting the Tri-hexamer Interface of the Viral Capsid. Structure 2019; 27:1234-1245.e5. [PMID: 31155311 PMCID: PMC7183857 DOI: 10.1016/j.str.2019.04.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/15/2019] [Accepted: 04/24/2019] [Indexed: 11/21/2022]
Abstract
The human antiviral protein MxB is a restriction factor that fights HIV infection. Previous experiments have demonstrated that MxB targets the HIV capsid, a protein shell that protects the viral genome. To make the conical-shaped capsid, HIV CA proteins are organized into a lattice composed of hexamer and pentamer building blocks, providing many interfaces for host proteins to recognize. Through extensive biochemical and biophysical studies and molecular dynamics simulations, we show that MxB is targeting the HIV capsid by recognizing the region created at the intersection of three CA hexamers. We are further able to map this interaction to a few CA residues, located in a negatively charged well at the interface between the three CA hexamers. This work provides detailed residue-level mapping of the targeted capsid interface and how MxB interacts. This information could inspire the development of capsid-targeting therapies for HIV.
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Affiliation(s)
- Sarah Sierra Smaga
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Chaoyi Xu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Brady James Summers
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | | | - Juan R Perilla
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
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35
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Wang T, Liu F, Tian G, Secombes CJ, Wang T. Lineage/species-specific expansion of the Mx gene family in teleosts: Differential expression and modulation of nine Mx genes in rainbow trout Oncorhynchus mykiss. FISH & SHELLFISH IMMUNOLOGY 2019; 90:413-430. [PMID: 31063803 DOI: 10.1016/j.fsi.2019.04.303] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/28/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
Myxovirus resistance (Mx) proteins are interferon (IFN)-inducible Dynamin-like GTPases, which play an important role in antiviral immunity. Three Mx genes (Mx1-3) have been cloned previously in rainbow trout. In this study, an additional six Mx genes were cloned that reside in four chromosomal loci. Further bioinformatics analysis suggests the presence of three teleost Mx groups (TMG) each with a characteristic gene organisation. Salmonid Mx belong to TMG1 and TMG2. The increased salmonid Mx gene copies are due mainly to local gene duplications that happened before and after salmonid speciation, in a lineage/species specific manner. Trout Mx molecules have been diversified in the loop 1 and 4 regions, and in the nuclear localisation signal in loop 4. The trout Mx genes were shown to be differentially expressed in tissues, with high levels of expression of TMG1 (Mx1-4) in blood and TMG2 (Mx5-9) in intestine. The expression of the majority of the trout Mx genes was induced by poly IC in vitro and in vivo, and increased during development. In addition, induction by antiviral (IFN) and proinflammatory cytokines was studied, and showed that type I IFN, IFNγ and IL-1β can induce Mx gene expression in an Mx gene-, cytokine- and cell line-dependent manner. These results show that salmonids possess a large number Mx genes as well as complex regulatory pathways, which may contribute to their success in an anadromous life style.
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Affiliation(s)
- Tingyu Wang
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - Fuguo Liu
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - Guangming Tian
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
| | - Christopher J Secombes
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK.
| | - Tiehui Wang
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK.
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36
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Buffone C, Kutzner J, Opp S, Martinez-Lopez A, Selyutina A, Coggings SA, Studdard LR, Ding L, Kim B, Spearman P, Schaller T, Diaz-Griffero F. The ability of SAMHD1 to block HIV-1 but not SIV requires expression of MxB. Virology 2019; 531:260-268. [PMID: 30959264 PMCID: PMC6487861 DOI: 10.1016/j.virol.2019.03.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/25/2019] [Accepted: 03/26/2019] [Indexed: 12/20/2022]
Abstract
SAMHD1 is a human restriction factor known to prevent infection of macrophages, resting CD4+ T cells, and dendritic cells by HIV-1. To test the contribution of MxB to the ability of SAMHD1 to block HIV-1 infection, we created human THP-1 cell lines that were knocked out for expression of MxB, SAMHD1, or both. Interestingly, MxB depletion renders SAMHD1 ineffective against HIV-1 but not SIVmac. We observed similar results in human primary macrophages that were knockdown for the expression of MxB. To understand how MxB assists SAMHD1 restriction of HIV-1, we examined direct interaction between SAMHD1 and MxB in pull-down experiments. In addition, we investigated several properties of SAMHD1 in the absence of MxB expression, including subcellular localization, phosphorylation of the SAMHD1 residue T592, and dNTPs levels. These experiments showed that SAMHD1 restriction of HIV-1 requires expression of MxB.
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Affiliation(s)
- Cindy Buffone
- Albert Einstein College of Medicine, Microbiology and Immunology, Bronx, NY, 10461, USA
| | - Juliane Kutzner
- University Hospital Heidelberg, Department of Infectious Diseases, Heidelberg, 69120, Germany
| | - Silvana Opp
- Albert Einstein College of Medicine, Microbiology and Immunology, Bronx, NY, 10461, USA
| | - Alicia Martinez-Lopez
- Albert Einstein College of Medicine, Microbiology and Immunology, Bronx, NY, 10461, USA
| | - Anastasia Selyutina
- Albert Einstein College of Medicine, Microbiology and Immunology, Bronx, NY, 10461, USA
| | | | | | - Lingmei Ding
- Cincinnati Children's Hospital, Infectious Diseases, Cincinnati, OH, 45229, USA
| | - Baek Kim
- Emory University, Pediatrics, Atlanta, 30322, Georgia
| | - Paul Spearman
- Cincinnati Children's Hospital, Infectious Diseases, Cincinnati, OH, 45229, USA
| | - Torsten Schaller
- University Hospital Heidelberg, Department of Infectious Diseases, Heidelberg, 69120, Germany
| | - Felipe Diaz-Griffero
- Albert Einstein College of Medicine, Microbiology and Immunology, Bronx, NY, 10461, USA.
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37
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Novikova M, Zhang Y, Freed EO, Peng K. Multiple Roles of HIV-1 Capsid during the Virus Replication Cycle. Virol Sin 2019; 34:119-134. [PMID: 31028522 PMCID: PMC6513821 DOI: 10.1007/s12250-019-00095-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 01/16/2019] [Indexed: 11/29/2022] Open
Abstract
Human immunodeficiency virus-1 capsid (HIV-1 CA) is involved in different stages of the viral replication cycle. During virion assembly, CA drives the formation of the hexameric lattice in immature viral particles, while in mature virions CA monomers assemble in cone-shaped cores surrounding the viral RNA genome and associated proteins. In addition to its functions in late stages of the viral replication cycle, CA plays key roles in a number of processes during early phases of HIV-1 infection including trafficking, uncoating, recognition by host cellular proteins and nuclear import of the viral pre-integration complex. As a result of efficient cooperation of CA with other viral and cellular proteins, integration of the viral genetic material into the host genome, which is an essential step for productive viral infection, successfully occurs. In this review, we will summarize available data on CA functions in HIV-1 replication, describing in detail its roles in late and early phases of the viral replication cycle.
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Affiliation(s)
- Mariia Novikova
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA
| | - Yulan Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Eric O Freed
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, 21702, USA.
| | - Ke Peng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
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38
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Human MxB Inhibits the Replication of Hepatitis C Virus. J Virol 2018; 93:JVI.01285-18. [PMID: 30333168 DOI: 10.1128/jvi.01285-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/08/2018] [Indexed: 12/21/2022] Open
Abstract
Type I interferon (IFN) inhibits viruses by inducing the expression of antiviral proteins. The IFN-induced myxovirus resistance B (MxB) protein has been reported to inhibit a limited number of viruses, including HIV-1 and herpesviruses, but its antiviral coverage remains to be explored further. Here we show that MxB interferes with RNA replication of hepatitis C virus (HCV) and significantly inhibits viral replication in a cyclophilin A (CypA)-dependent manner. Our data further show that MxB interacts with the HCV protein NS5A, thereby impairing NS5A interaction with CypA and NS5A localization to the endoplasmic reticulum, two events essential for HCV RNA replication. Interestingly, we found that MxB significantly inhibits two additional CypA-dependent viruses of the Flaviviridae family, namely, Japanese encephalitis virus and dengue virus, suggesting a potential link between virus dependence on CypA and virus susceptibility to MxB inhibition. Collectively, these data have identified MxB as a key factor behind IFN-mediated suppression of HCV infection, and they suggest that other CypA-dependent viruses may also be subjected to MxB restriction.IMPORTANCE Viruses of the Flaviviridae family cause major illness and death around the world and thus pose a great threat to human health. Here we show that IFN-inducible MxB restricts several members of the Flaviviridae, including HCV, Japanese encephalitis virus, and dengue virus. This finding not only suggests an active role of MxB in combating these major pathogenic human viruses but also significantly expands the antiviral spectrum of MxB. Our study further strengthens the link between virus dependence on CypA and susceptibility to MxB restriction and also suggests that MxB may employ a common mechanism to inhibit different viruses. Elucidating the antiviral functions of MxB advances our understanding of IFN-mediated host antiviral defense and may open new avenues to the development of novel antiviral therapeutics.
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Dicks MDJ, Betancor G, Jimenez-Guardeño JM, Pessel-Vivares L, Apolonia L, Goujon C, Malim MH. Multiple components of the nuclear pore complex interact with the amino-terminus of MX2 to facilitate HIV-1 restriction. PLoS Pathog 2018; 14:e1007408. [PMID: 30496303 PMCID: PMC6264145 DOI: 10.1371/journal.ppat.1007408] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 10/15/2018] [Indexed: 12/13/2022] Open
Abstract
Human myxovirus resistance 2 (MX2/MXB) is an interferon-induced post-entry inhibitor of human immunodeficiency virus type-1 (HIV-1) infection. While the precise mechanism of viral inhibition remains unclear, MX2 is localized to the nuclear envelope, and blocks the nuclear import of viral cDNAs. The amino-terminus of MX2 (N-MX2) is essential for anti-viral function, and mutation of a triple arginine motif at residues 11 to 13 abrogates anti-HIV-1 activity. In this study, we sought to investigate the role of N-MX2 in anti-viral activity by identifying functionally relevant host-encoded interaction partners through yeast-two-hybrid screening. Remarkably, five out of seven primary candidate interactors were nucleoporins or nucleoporin-like proteins, though none of these candidates were identified when screening with a mutant RRR11-13A N-MX2 fragment. Interactions were confirmed by co-immunoprecipitation, and RNA silencing experiments in cell lines and primary CD4+ T cells demonstrated that multiple components of the nuclear pore complex and nuclear import machinery can impact MX2 anti-viral activity. In particular, the phenylalanine-glycine (FG) repeat containing cytoplasmic filament nucleoporin NUP214, and transport receptor transportin-1 (TNPO1) were consistently required for full MX2, and interferon-mediated, anti-viral function. Both proteins were shown to interact with the triple arginine motif, and confocal fluorescence microscopy revealed that their simultaneous depletion resulted in diminished MX2 accumulation at the nuclear envelope. We therefore propose a model whereby multiple components of the nuclear import machinery and nuclear pore complex help position MX2 at the nuclear envelope to promote MX2-mediated restriction of HIV-1. The movement of large molecules into the cell nucleus is regulated at specific sites within the nuclear envelope termed nuclear pores. To infect cells productively, human immunodeficiency virus type-1 (HIV-1) must traverse the nuclear envelope to enable integration of the viral DNA into the genomic DNA of host cells. We, and others, have previously identified a cell-encoded protein, human myxovirus resistance 2 (MX2), which is expressed upon initiation of an innate immune response and prevents accumulation of HIV-1 DNA within the nucleus, thus imposing a block to infection. Here, we reveal that components of the nuclear pore complex, and nuclear import machinery, are required for MX2-dependent inhibition of HIV-1 infection. We show that MX2, which is localized at the cytoplasmic face of the nuclear envelope, interacts with multiple protein components of the nuclear pore complex, as well as transport receptor transportin-1, via a functionally required triple arginine motif at its amino-terminus. We speculate that these interactions facilitate MX2-mediated inhibition of HIV-1 nuclear import by situating the protein at the nuclear envelope.
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Affiliation(s)
- Matthew D. J. Dicks
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
| | - Gilberto Betancor
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
| | - Jose M. Jimenez-Guardeño
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
| | - Lucie Pessel-Vivares
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
| | - Luis Apolonia
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
| | - Caroline Goujon
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
| | - Michael H. Malim
- Department of Infectious Diseases, School of Immunology & Microbial Sciences, King’s College London, London, United Kingdom
- * E-mail:
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40
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Human MX2/MxB: a Potent Interferon-Induced Postentry Inhibitor of Herpesviruses and HIV-1. J Virol 2018; 92:JVI.00709-18. [PMID: 30258007 DOI: 10.1128/jvi.00709-18] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Interferons limit viral replication by inducing intracellular restriction factors, such as the GTPase MxB (also designated MX2), which inhibits HIV-1 and, as recently shown, herpesviruses. Inhibition of these viruses occurs at ill-defined steps after viral entry and requires formation of MxB dimers or oligomers, but GTP hydrolysis is needed only for blocking herpesviruses. Together with previous findings on related MxA, the new research on MxB highlights the mechanistic diversity by which MX proteins interfere with viral replication.
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41
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From APOBEC to ZAP: Diverse mechanisms used by cellular restriction factors to inhibit virus infections. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:382-394. [PMID: 30290238 PMCID: PMC6334645 DOI: 10.1016/j.bbamcr.2018.09.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 08/28/2018] [Accepted: 09/23/2018] [Indexed: 12/30/2022]
Abstract
Antiviral restriction factors are cellular proteins that inhibit the entry, replication, or spread of viruses. These proteins are critical components of the innate immune system and function to limit the severity and host range of virus infections. Here we review the current knowledge on the mechanisms of action of several restriction factors that affect multiple viruses at distinct stages of their life cycles. For example, APOBEC3G deaminates cytosines to hypermutate reverse transcribed viral DNA; IFITM3 alters membranes to inhibit virus membrane fusion; MXA/B oligomerize on viral protein complexes to inhibit virus replication; SAMHD1 decreases dNTP intracellular concentrations to prevent reverse transcription of retrovirus genomes; tetherin prevents release of budding virions from cells; Viperin catalyzes formation of a nucleoside analogue that inhibits viral RNA polymerases; and ZAP binds virus RNAs to target them for degradation. We also discuss countermeasures employed by specific viruses against these restriction factors, and mention secondary functions of several of these factors in modulating immune responses. These important examples highlight the diverse strategies cells have evolved to combat virus infections.
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42
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MXB inhibits murine cytomegalovirus. Virology 2018; 522:158-167. [DOI: 10.1016/j.virol.2018.07.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/09/2018] [Accepted: 07/13/2018] [Indexed: 01/02/2023]
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43
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Equine Myxovirus Resistance Protein 2 Restricts Lentiviral Replication by Blocking Nuclear Uptake of Capsid Protein. J Virol 2018; 92:JVI.00499-18. [PMID: 29743377 PMCID: PMC6146692 DOI: 10.1128/jvi.00499-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 04/26/2018] [Indexed: 12/23/2022] Open
Abstract
Previous research has shown that the antiviral ability of Mx2s is confined to primates, particularly humans. EIAV has been shown to be insensitive to restriction by human MxB. Here, we describe the function of equine Mx2. This protein plays an important role in the suppression of EIAV, HIV-1, and SIVs. The antiviral activity of eqMx2 depends on its subcellular location as well as its capsid binding capacity. Our results showed that following viral infection, eqMx2 changes its original cytoplasmic location and accumulates at the nuclear envelope, where it binds to the viral capsid and blocks the nuclear entry of reverse-transcribed proviral DNAs. In contrast, huMxB does not bind to the EIAV capsid and shows no EIAV restriction effect. These studies expand our understanding of the function of the equine Mx2 protein. Human myxovirus resistance protein 2 (huMxB) has been shown to be a determinant type I interferon (IFN)-induced host factor involved in the inhibition of human immunodeficiency virus type 1 (HIV-1) as well as many other primate lentiviruses. This blocking occurs after the reverse transcription of viral RNA and ahead of integration into the host DNA, which is closely connected to the ability of the protein to bind the viral capsid. To date, Mx2s derived from nonprimate animals have shown no capacity for HIV-1 suppression. In this study, we examined the restrictive effect of equine Mx2 (eqMx2) on both equine infectious anemia virus (EIAV) and HIV-1 and investigated possible mechanisms for its specific function. We demonstrated that IFN-α/β upregulates the expression of eqMx2 in equine monocyte-derived macrophages (eMDMs). The overexpression of eqMx2 significantly suppresses the replication of EIAV, HIV-1, and simian immunodeficiency viruses (SIVs) but not that of murine leukemia virus (MLV). The knockdown of eqMx2 transcription weakens the inhibition of EIAV replication by type I interferon. Interestingly, data from immunofluorescence assays suggest that the subcellular localization of eqMx2 changes following virus infection, from being dispersed in the cytoplasm to being accumulated at the nuclear envelope. Furthermore, eqMx2 blocks the nuclear uptake of the proviral genome by binding to the viral capsid. The N-terminally truncated mutant of eqMx2 lost the ability to bind the viral capsid as well as the restriction effect for lentiviruses. These results improve our understanding of the Mx2 protein in nonprimate animals. IMPORTANCE Previous research has shown that the antiviral ability of Mx2s is confined to primates, particularly humans. EIAV has been shown to be insensitive to restriction by human MxB. Here, we describe the function of equine Mx2. This protein plays an important role in the suppression of EIAV, HIV-1, and SIVs. The antiviral activity of eqMx2 depends on its subcellular location as well as its capsid binding capacity. Our results showed that following viral infection, eqMx2 changes its original cytoplasmic location and accumulates at the nuclear envelope, where it binds to the viral capsid and blocks the nuclear entry of reverse-transcribed proviral DNAs. In contrast, huMxB does not bind to the EIAV capsid and shows no EIAV restriction effect. These studies expand our understanding of the function of the equine Mx2 protein.
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44
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Role of MxB in Alpha Interferon-Mediated Inhibition of HIV-1 Infection. J Virol 2018; 92:JVI.00422-18. [PMID: 29925663 DOI: 10.1128/jvi.00422-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 06/15/2018] [Indexed: 01/20/2023] Open
Abstract
Type I interferon inhibits viruses through inducing the expression of antiviral proteins, including the myxovirus resistance (Mx) proteins. Compared to the human MxA protein, which inhibits a wide range of viruses, the MxB protein has been reported to specifically inhibit primate lentiviruses, including HIV-1, and herpesviruses. Further, the role of endogenous MxB in alpha interferon-mediated inhibition of HIV-1 infection was questioned by a recent study showing that MxB knockout did not increase the level of infection by HIV-1 which carried the G protein of vesicular stomatitis virus (VSV), allowing infection of CD4-negative HT1080 cells. In order to further examine the anti-HIV-1 activity of endogenous MxB, we have used CRISPR/Cas9 to deplete MxB in different cell lines and observed a substantial restoration of HIV-1 infection in the presence of alpha interferon treatment. However, this rescue effect of MxB knockout became much less pronounced when infection was performed with HIV-1 carrying the VSV G protein. Interestingly, a CRISPR/Cas9 knockout screen of alpha interferon-stimulated genes in U87-MG cells revealed that the genes for interferon-induced transmembrane protein 2 (IFITM2) and IFITM3 inhibited VSV G-pseudotyped HIV-1 much more strongly than the rest of the genes tested, including the gene for MxB. Therefore, our results demonstrate the importance of MxB in alpha interferon-mediated inhibition of HIV-1 infection, which, however, can be underestimated if infection is performed with VSV G protein-pseudotyped HIV-1, due to the high sensitivity of VSV G-mediated infection to inhibition by IFITM proteins.IMPORTANCE The results of this study reconcile the controversial reports regarding the anti-HIV-1 function of alpha interferon-induced MxB protein. In addition to the different cell types that may have contributed to the different observations, our data also suggest that VSV G protein-pseudotyped HIV-1 is much less inhibited by alpha interferon-induced MxB than HIV-1 itself is. Our results clearly demonstrate an important contribution of MxB to alpha interferon-mediated inhibition of HIV-1 in CD4+ T cells, which calls for using HIV-1 target cells and wild-type virus to test the relevance of the anti-HIV-1 activity of endogenous MxB and other restriction factors.
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45
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Human MxB Protein Is a Pan-herpesvirus Restriction Factor. J Virol 2018; 92:JVI.01056-18. [PMID: 29950411 DOI: 10.1128/jvi.01056-18] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 01/24/2023] Open
Abstract
Herpesvirus infections are highly prevalent in the human population and persist for life. They are often acquired subclinically but potentially progress to life-threatening diseases in immunocompromised individuals. The interferon system is indispensable for the control of herpesviral replication. However, the responsible antiviral effector mechanisms are not well characterized. The type I interferon-induced, human myxovirus resistance 2 (MX2) gene product MxB, a dynamin-like large GTPase, has recently been identified as a potent inhibitor of HIV-1. We now show that MxB also interferes with an early step of herpesvirus replication, affecting alpha-, beta-, and gammaherpesviruses before or at the time of immediate early gene expression. Defined MxB mutants influencing GTP binding and hydrolysis revealed that the effector mechanism against herpesviruses is thoroughly different from that against HIV-1. Overall, our findings demonstrate that MxB serves as a broadly acting intracellular restriction factor that controls the establishment of not only retrovirus but also herpesvirus infection of all three subfamilies.IMPORTANCE Human herpesviruses pose a constant threat to human health. Reactivation of persisting herpesvirus infections, particularly in immunocompromised individuals and the elderly, can cause severe diseases, such as zoster, pneumonia, encephalitis, or cancer. The interferon system is relevant for the control of herpesvirus replication as exemplified by fatal disease outcomes in patients with primary immunodeficiencies. Here, we describe the interferon-induced, human MX2 gene product MxB as an efficient restriction factor of alpha-, beta-, and gammaherpesviruses. MxB has previously been described as an inhibitor of HIV-1. Importantly, our mutational analyses of MxB reveal an antiviral mechanism of herpesvirus restriction distinct from that against HIV-1. Thus, the dynamin-like MxB GTPase serves as a broadly acting intracellular restriction factor that controls retrovirus as well as herpesvirus infections.
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Kane M, Rebensburg SV, Takata MA, Zang TM, Yamashita M, Kvaratskhelia M, Bieniasz PD. Nuclear pore heterogeneity influences HIV-1 infection and the antiviral activity of MX2. eLife 2018; 7:e35738. [PMID: 30084827 PMCID: PMC6101944 DOI: 10.7554/elife.35738] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 08/06/2018] [Indexed: 12/14/2022] Open
Abstract
HIV-1 accesses the nuclear DNA of interphase cells via a poorly defined process involving functional interactions between the capsid protein (CA) and nucleoporins (Nups). Here, we show that HIV-1 CA can bind multiple Nups, and that both natural and manipulated variation in Nup levels impacts HIV-1 infection in a manner that is strikingly dependent on cell-type, cell-cycle, and cyclophilin A (CypA). We also show that Nups mediate the function of the antiviral protein MX2, and that MX2 can variably inhibit non-viral NLS function. Remarkably, both enhancing and inhibiting effects of cyclophilin A and MX2 on various HIV-1 CA mutants could be induced or abolished by manipulating levels of the Nup93 subcomplex, the Nup62 subcomplex, NUP88, NUP214, RANBP2, or NUP153. Our findings suggest that several Nup-dependent 'pathways' are variably exploited by HIV-1 to target host DNA in a cell-type, cell-cycle, CypA and CA-sequence dependent manner, and are differentially inhibited by MX2.
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Affiliation(s)
- Melissa Kane
- Laboratory of RetrovirologyThe Rockefeller UniversityNew YorkUnited States
| | - Stephanie V Rebensburg
- Division of Infectious DiseasesUniversity of Colorado School of MedicineAuroraUnited States
| | - Matthew A Takata
- Laboratory of RetrovirologyThe Rockefeller UniversityNew YorkUnited States
| | - Trinity M Zang
- Laboratory of RetrovirologyThe Rockefeller UniversityNew YorkUnited States
- Howard Hughes Medical InstituteNew YorkUnited States
| | | | - Mamuka Kvaratskhelia
- Division of Infectious DiseasesUniversity of Colorado School of MedicineAuroraUnited States
| | - Paul D Bieniasz
- Laboratory of RetrovirologyThe Rockefeller UniversityNew YorkUnited States
- Howard Hughes Medical InstituteNew YorkUnited States
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Meier K, Jaguva Vasudevan AA, Zhang Z, Bähr A, Kochs G, Häussinger D, Münk C. Equine MX2 is a restriction factor of equine infectious anemia virus (EIAV). Virology 2018; 523:52-63. [PMID: 30081309 DOI: 10.1016/j.virol.2018.07.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/19/2018] [Accepted: 07/24/2018] [Indexed: 01/23/2023]
Abstract
Human myxovirus resistance protein B (hMXB) is a restriction factor of HIV-1 that also inhibits a variety of retroviruses. However, hMXB is not antiviral against equine infectious anemia virus (EIAV). We show here that equine MX2 (eMX2) potently restricts EIAV in vitro. Additionally, eMX2 inhibits HIV-1 and other lentiviruses, including murine leukemia virus. Previously, it was reported that hMXB repression is reduced in hMXB Δ1-25, but not in GTP-binding mutant K131A and GTP-hydrolysis mutant T151A. In contrast to this phenomenon, our study indicates that eMX2 restriction is not diminished in eMX2 Δ1-25, but is in eMX2 K127A and T147A, which correspond to hMXB K131A and T151A, respectively. Thus, eMX2 may inhibit retroviral replication by a novel mechanism that differs from that of hMXB.
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Affiliation(s)
- Kristina Meier
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Ananda Ayyappan Jaguva Vasudevan
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Zeli Zhang
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Ariane Bähr
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Georg Kochs
- Institute of Virology, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Herman-Herder-Str. 1, 79104 Freiburg, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University, Moorenstr. 5, 40225 Düsseldorf, Germany.
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Chen S, Zeng M, Liu P, Yang C, Wang M, Jia R, Zhu D, Liu M, Yang Q, Wu Y, Zhao X, Cheng A. The 125th Lys and 145th Thr Amino Acids in the GTPase Domain of Goose Mx Confer Its Antiviral Activity against the Tembusu Virus. Viruses 2018; 10:v10070361. [PMID: 29986463 PMCID: PMC6070871 DOI: 10.3390/v10070361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 06/29/2018] [Accepted: 07/04/2018] [Indexed: 12/14/2022] Open
Abstract
The Tembusu virus (TMUV) is an avian pathogenic flavivirus that causes a highly contagious disease and catastrophic losses to the poultry industry. The myxovirus resistance protein (Mx) of innate immune effectors is a key antiviral “workhorse” of the interferon (IFN) system. Although mammalian Mx resistance against myxovirus and retrovirus was witnessed for decades, whether or not bird Mx has anti-flavivirus activity remains unknown. In this study, we found that the transcription of goose Mx (goMx) was obviously driven by TMUV infection, both in vivo and in vitro, and that the titers and copies of TMUV were significantly reduced by goMx overexpression. In both primary (goose embryo fibroblasts, GEFs) and passaged cells (baby hamster kidney cells, BHK21, and human fetal kidney cells, HEK 293T), it was shown that goMx was mainly located in the cytoplasm, and sporadically distributed in the nucleus. The intracellular localization of this protein is attributed to the predicted bipartite nuclear localization signal (NLS; 30 residues: the 441st–471st amino acids of goMx). Intuitively, it seems that the cells with a higher level of goMx expression tend to have lower TMUV loads in the cytoplasm, as determined by an immunofluorescence assay. To further explore the antiviral determinants, a panel of variants was constructed. Two amino acids at the 125th (Lys) and 145th (Thr) positions in GTP-binding elements, not in the L4 loop (40 residues: the 532nd–572nd amino acids of goMx), were vital for the antiviral function of goMx against TMUV in vitro. These findings will contribute to our understanding of the functional significance of the antiviral system in aquatic birds, and the development of goMx could be a valuable therapeutic agent against TMUV.
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Affiliation(s)
- Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Miao Zeng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
| | - Peng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
| | - Chao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Dekang Zhu
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, No. 211 Huimin Road, Wenjiang District, Chengdu 611130, Sichuan, China.
- Research Center of Avian Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
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MxB is an interferon-induced restriction factor of human herpesviruses. Nat Commun 2018; 9:1980. [PMID: 29773792 PMCID: PMC5958057 DOI: 10.1038/s41467-018-04379-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 04/19/2018] [Indexed: 12/12/2022] Open
Abstract
The type I interferon (IFN) system plays an important role in controlling herpesvirus infections, but it is unclear which IFN-mediated effectors interfere with herpesvirus replication. Here we report that human myxovirus resistance protein B (MxB, also designated Mx2) is a potent human herpesvirus restriction factor in the context of IFN. We demonstrate that ectopic MxB expression restricts a range of herpesviruses from the Alphaherpesvirinae and Gammaherpesvirinae, including herpes simplex virus 1 and 2 (HSV-1 and HSV-2), and Kaposi’s sarcoma-associated herpesvirus (KSHV). MxB restriction of HSV-1 and HSV-2 requires GTPase function, in contrast to restriction of lentiviruses. MxB inhibits the delivery of incoming HSV-1 DNA to the nucleus and the appearance of empty capsids, but not the capsid delivery to the cytoplasm or tegument dissociation from the capsid. Our study identifies MxB as a potent pan-herpesvirus restriction factor which blocks the uncoating of viral DNA from the incoming viral capsid. MxB is an interferon-induced GTPase that inhibits HIV replication. Here, Crameri et al. show that MxB restricts replication of herpesviruses by inhibiting delivery of incoming viral DNA into the nucleus, and this antiviral activity depends on MxB’s GTPase activity.
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Nakayama EE, Saito A, Sultana T, Jin Z, Nohata K, Shibata M, Hosoi M, Motomura K, Shioda T, Sangkitporn S, Loket R, Saeng-aroon S. Naturally Occurring Mutations in HIV-1 CRF01_AE Capsid Affect Viral Sensitivity to Restriction Factors. AIDS Res Hum Retroviruses 2018; 34:382-392. [PMID: 29325426 PMCID: PMC5899301 DOI: 10.1089/aid.2017.0212] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
TRIM5α and MxB are known as restriction factors that inhibit the early step of intracellular HIV-1 replication cycle. Both factors are believed to interact with the incoming virus core to suppress HIV-1 infection. The extreme diversity of HIV-1 is thought to be a consequence of its propensity to mutate to escape immune responses and host restriction factors. We recently determined the capsid sequences for 144 HIV-1 CRF01_AE viruses obtained in Thailand from 2005 to 2011. In this study, we further analyzed the amino acid variations among the capsid sequences of 204 HIV-1 CRF01_AE obtained in Thailand and China, including 84 of the aforementioned 144 viruses, to detect mutations permitting escape from restriction by host factors. We found a characteristic combination of E79D, V83T, and H87Q in sequences from Chinese viruses and subsequently showed that this combination conferred partial resistance to MxB. Interestingly, this combination conferred resistance to human TRIM5α as well. The H87Q mutation alone conferred resistance to MxB in the CRF01_AE background, but not in subtype B virus. In contrast, the H87Q mutation alone conferred resistance to human TRIM5α in both the CFR01_AE and subtype B backgrounds. BLAST analysis revealed the presence of the E79D, V83T, and H87Q combination in CRF01_AE viruses isolated not only in China but also in many other countries. Although the mechanistic details as well as precise role of MxB antiviral activity in infected individuals remain to be clarified, our data suggest an interaction between MxB and the HIV-1 capsid in vivo.
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Affiliation(s)
- Emi E. Nakayama
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Akatsuki Saito
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Tahmina Sultana
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Zhuan Jin
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Kyotaro Nohata
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Masato Shibata
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Miho Hosoi
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Kazushi Motomura
- Thailand-Japan Research Collaboration Center on Emerging and Re-Emerging Infections (RCC-ERI), Osaka University, Nonthaburi, Thailand
| | - Tatsuo Shioda
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Somchai Sangkitporn
- National Institute of Health, Department of Medical Science, Ministry of Public Health, Nonthaburi, Thailand
| | - Ruangchai Loket
- National Institute of Health, Department of Medical Science, Ministry of Public Health, Nonthaburi, Thailand
| | - Siriphan Saeng-aroon
- National Institute of Health, Department of Medical Science, Ministry of Public Health, Nonthaburi, Thailand
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