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Long M, Toesca J, Guillon C. Review and Perspectives on the Structure-Function Relationships of the Gag Subunits of Feline Immunodeficiency Virus. Pathogens 2021; 10:pathogens10111502. [PMID: 34832657 PMCID: PMC8621984 DOI: 10.3390/pathogens10111502] [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: 10/04/2021] [Revised: 11/16/2021] [Accepted: 11/16/2021] [Indexed: 11/16/2022] Open
Abstract
The Gag polyprotein is implied in the budding as well as the establishment of the supramolecular architecture of infectious retroviral particles. It is also involved in the early phases of the replication of retroviruses by protecting and transporting the viral genome towards the nucleus of the infected cell until its integration in the host genome. Therefore, understanding the structure-function relationships of the Gag subunits is crucial as each of them can represent a therapeutic target. Though the field has been explored for some time in the area of Human Immunodeficiency Virus (HIV), it is only in the last decade that structural data on Feline Immunodeficiency Virus (FIV) Gag subunits have emerged. As FIV is an important veterinary issue, both in domestic cats and endangered feline species, such data are of prime importance for the development of anti-FIV molecules targeting Gag. This review will focus on the recent advances and perspectives on the structure-function relationships of each subunit of the FIV Gag polyprotein.
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Affiliation(s)
- Mathieu Long
- Retroviruses and Structural Biochemistry, Molecular Microbiology and Structural Biochemistry, CNRS, Univ Lyon, UMR5086, 69007 Lyon, France; (M.L.); (J.T.)
- Center for Molecular Protein Science, Department of Chemistry, Lund University, Lund, 221 00 Scania, Sweden
| | - Johan Toesca
- Retroviruses and Structural Biochemistry, Molecular Microbiology and Structural Biochemistry, CNRS, Univ Lyon, UMR5086, 69007 Lyon, France; (M.L.); (J.T.)
- Enveloped Viruses, Vectors and Immunotherapy, CIRI-Centre International de Recherche en Infectiologie, Univ Lyon, Université Claude Bernard Lyon 1, UMR5308, ENS Lyon, 69007 Lyon, France
| | - Christophe Guillon
- Retroviruses and Structural Biochemistry, Molecular Microbiology and Structural Biochemistry, CNRS, Univ Lyon, UMR5086, 69007 Lyon, France; (M.L.); (J.T.)
- Correspondence:
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Brown JB, Summers HR, Brown LA, Marchant J, Canova PN, O'Hern CT, Abbott ST, Nyaunu C, Maxwell S, Johnson T, Moser MB, Ablan SD, Carter H, Freed EO, Summers MF. Structural and Mechanistic Studies of the Rare Myristoylation Signal of the Feline Immunodeficiency Virus. J Mol Biol 2020; 432:4076-4091. [PMID: 32442659 PMCID: PMC7316625 DOI: 10.1016/j.jmb.2020.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 10/24/2022]
Abstract
All retroviruses encode a Gag polyprotein containing an N-terminal matrix domain (MA) that anchors Gag to the plasma membrane and recruits envelope glycoproteins to virus assembly sites. Membrane binding by the Gag protein of HIV-1 and most other lentiviruses is dependent on N-terminal myristoylation of MA by host N-myristoyltransferase enzymes (NMTs), which recognize a six-residue "myristoylation signal" with consensus sequence: M1GXXX[ST]. For unknown reasons, the feline immunodeficiency virus (FIV), which infects both domestic and wild cats, encodes a non-consensus myristoylation sequence not utilized by its host or by other mammals (most commonly: M1GNGQG). To explore the evolutionary basis for this sequence, we compared the structure, dynamics, and myristoylation properties of native FIV MA with a mutant protein containing a consensus feline myristoylation motif (MANOS) and examined the impact of MA mutations on virus assembly and ability to support spreading infection. Unexpectedly, myristoylation efficiency of MANOS in Escherichia coli by co-expressed mammalian NMT was reduced by ~70% compared to the wild-type protein. NMR studies revealed that residues of the N-terminal myristoylation signal are fully exposed and mobile in the native protein but partially sequestered in the MANOS chimera, suggesting that the unusual FIV sequence is conserved to promote exposure and efficient myristoylation of the MA N terminus. In contrast, virus assembly studies indicate that the MANOS mutation does not affect virus assembly, but does prevent virus spread, in feline kidney cells. Our findings indicate that residues of the FIV myristoylation sequence play roles in replication beyond NMT recognition and Gag-membrane binding.
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Affiliation(s)
- Janae B Brown
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Holly R Summers
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Lola A Brown
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Jan Marchant
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Paige N Canova
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Colin T O'Hern
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Sophia T Abbott
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Constance Nyaunu
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Simon Maxwell
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Talayah Johnson
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Morgan B Moser
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Sherimay D Ablan
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, National Cancer Institute at Fredrick, Fredrick, MD 21702-1201, USA
| | - Hannah Carter
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, National Cancer Institute at Fredrick, Fredrick, MD 21702-1201, USA
| | - Eric O Freed
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, National Cancer Institute at Fredrick, Fredrick, MD 21702-1201, USA.
| | - Michael F Summers
- Howard Hughes Medical Institute and Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, USA.
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Properties and Functions of Feline Immunodeficiency Virus Gag Domains in Virion Assembly and Budding. Viruses 2018; 10:v10050261. [PMID: 29772651 PMCID: PMC5977254 DOI: 10.3390/v10050261] [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] [Received: 04/05/2018] [Revised: 05/13/2018] [Accepted: 05/14/2018] [Indexed: 01/11/2023] Open
Abstract
Feline immunodeficiency virus (FIV) is an important cat pathogen worldwide whose biological and pathophysiological properties resemble those of human immunodeficiency virus type 1 (HIV-1). Therefore, the study of FIV not only benefits its natural host but is also useful for the development of antiviral strategies directed against HIV-1 infections in humans. FIV assembly results from the multimerization of a single but complex viral polypeptide, the Gag precursor. In this review, we will first give an overview of the current knowledge of the proteins encoded by the FIV pol, env, rev, vif, and orf-A genes, and then we will describe and discuss in detail the critical roles that each of the FIV Gag domains plays in virion morphogenesis. Since retroviral assembly is an attractive target for therapeutic interventions, gaining a better understanding of this process is highly desirable.
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Leloup N, Lössl P, Meijer DH, Brennich M, Heck AJR, Thies-Weesie DME, Janssen BJC. Low pH-induced conformational change and dimerization of sortilin triggers endocytosed ligand release. Nat Commun 2017; 8:1708. [PMID: 29167428 PMCID: PMC5700061 DOI: 10.1038/s41467-017-01485-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 09/19/2017] [Indexed: 11/24/2022] Open
Abstract
Low pH-induced ligand release and receptor recycling are important steps for endocytosis. The transmembrane protein sortilin, a β-propeller containing endocytosis receptor, internalizes a diverse set of ligands with roles in cell differentiation and homeostasis. The molecular mechanisms of pH-mediated ligand release and sortilin recycling are unresolved. Here we present crystal structures that show the sortilin luminal segment (s-sortilin) undergoes a conformational change and dimerizes at low pH. The conformational change, within all three sortilin luminal domains, provides an altered surface and the dimers sterically shield a large interface while bringing the two s-sortilin C-termini into close proximity. Biophysical and cell-based assays show that members of two different ligand families, (pro)neurotrophins and neurotensin, preferentially bind the sortilin monomer. This indicates that sortilin dimerization and conformational change discharges ligands and triggers recycling. More generally, this work may reveal a double mechanism for low pH-induced ligand release by endocytosis receptors. Sortilin is an endocytosis receptor with a luminal β-propeller domain. Here the authors present the structures of the β-propeller domain at neutral and acidic pH, which reveal that sortilin dimerises and undergoes conformational changes at low pH and further propose a model for low pH-induced ligand release by endocytosis receptors.
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Affiliation(s)
- Nadia Leloup
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Philip Lössl
- Biomolecular Mass Spectrometry & Proteomics and Netherlands Proteomics Center, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Dimphna H Meijer
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Martha Brennich
- European Molecular Biology Laboratory, Grenoble Outstation, Grenoble, 38000, France
| | - Albert J R Heck
- Biomolecular Mass Spectrometry & Proteomics and Netherlands Proteomics Center, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Dominique M E Thies-Weesie
- Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Bert J C Janssen
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands.
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Folio C, Sierra N, Dujardin M, Alvarez G, Guillon C. Crystal Structure of the Full-Length Feline Immunodeficiency Virus Capsid Protein Shows an N-Terminal β-Hairpin in the Absence of N-Terminal Proline. Viruses 2017; 9:v9110335. [PMID: 29120364 PMCID: PMC5707542 DOI: 10.3390/v9110335] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/03/2017] [Accepted: 11/08/2017] [Indexed: 12/31/2022] Open
Abstract
Feline immunodeficiency virus (FIV) is a member of the Retroviridae family. It is the causative agent of an acquired immunodeficiency syndrome (AIDS) in cats and wild felines. Its capsid protein (CA) drives the assembly of the viral particle, which is a critical step in the viral replication cycle. Here, the first atomic structure of full-length FIV CA to 1.67 Å resolution is determined. The crystallized protein exhibits an original tetrameric assembly, composed of dimers which are stabilized by an intermolecular disulfide bridge induced by the crystallogenesis conditions. The FIV CA displays a standard α-helical CA topology with two domains, separated by a linker shorter than other retroviral CAs. The β-hairpin motif at its amino terminal end, which interacts with nucleotides in HIV-1, is unusually long in FIV CA. Interestingly, this functional β-motif is formed in this construct in the absence of the conserved N-terminal proline. The FIV CA exhibits a cis Arg–Pro bond in the CypA-binding loop, which is absent in known structures of lentiviral CAs. This structure represents the first tri-dimensional structure of a functional, full-length FIV CA.
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Affiliation(s)
- Christelle Folio
- Equipe Rétrovirus et Biochimie Structurale, Université de Lyon, CNRS, MMSB, UMR 5086 CNRS/Université de Lyon, IBCP, Lyon 69367 CEDEX 07, France.
| | - Natalia Sierra
- Laboratorio de Moléculas Bioactivas, Centro Universitario Regional Litoral Norte, Universidad de la República, Paysandú 60000, Uruguay.
| | - Marie Dujardin
- Equipe Rétrovirus et Biochimie Structurale, Université de Lyon, CNRS, MMSB, UMR 5086 CNRS/Université de Lyon, IBCP, Lyon 69367 CEDEX 07, France.
| | - Guzman Alvarez
- Laboratorio de Moléculas Bioactivas, Centro Universitario Regional Litoral Norte, Universidad de la República, Paysandú 60000, Uruguay.
| | - Christophe Guillon
- Equipe Rétrovirus et Biochimie Structurale, Université de Lyon, CNRS, MMSB, UMR 5086 CNRS/Université de Lyon, IBCP, Lyon 69367 CEDEX 07, France.
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Verrier B, Paul S, Terrat C, Bastide L, Ensinas A, Phelip C, Chanut B, Bulens-Grassigny L, Jospin F, Guillon C. Exploiting Natural Cross-reactivity between Human Immunodeficiency Virus (HIV)-1 p17 Protein and Anti-gp41 2F5 Antibody to Induce HIV-1 Neutralizing Responses In Vivo. Front Immunol 2017; 8:770. [PMID: 28713388 PMCID: PMC5491952 DOI: 10.3389/fimmu.2017.00770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 06/16/2017] [Indexed: 11/26/2022] Open
Abstract
Anti-p17 antibodies are able to neutralize human immunodeficiency virus (HIV) entry in a mouse model. In this study, we identified a region of sequence similarity between the epitopes of anti-p17 neutralizing antibodies and anti-gp41 neutralizing 2F5 antibody and verified cross-reactivity between p17 and 2F5 in vitro. The p17 sequence was modified to increase sequence identity between the p17 and 2F5 epitopes, which resulted in enhanced cross-reactivity in vitro. Immunogenicity of wild-type and modified p17 was characterized in a rabbit model. Both wild-type and mutated p17 induced anti-gp41 responses in rabbits; sera from these animals reacted with gp41 from different HIV clades. Moreover, introduction of the 2F5 sequence in p17 resulted in induction of antibodies with partially neutralizing activity. Based upon these data, we suggest that the natural cross-reactivity between HIV-1 p17 protein and 2F5 antibody can be exploited to induce antibodies with neutralizing activity in an animal model.
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Affiliation(s)
- Bernard Verrier
- Colloidal Vectors and Tissue Transport, UMR5305, Institut de Biologie et Chimie des Protéines, Université de Lyon, CNRS, Lyon, France
| | - Stéphane Paul
- Groupe sur l’Immunité des Muqueuses et Agents Pathogènes, EA3064, Faculté de Médecine Jacques Lisfranc, Université de Lyon, Saint-Etienne, France
| | - Céline Terrat
- Colloidal Vectors and Tissue Transport, UMR5305, Institut de Biologie et Chimie des Protéines, Université de Lyon, CNRS, Lyon, France
| | - Liza Bastide
- Retroviruses and Structural Biochemistry, UMR5086, Institut de Biologie et Chimie des Protéines, Université de Lyon, CNRS, Lyon, France
| | - Agathe Ensinas
- Colloidal Vectors and Tissue Transport, UMR5305, Institut de Biologie et Chimie des Protéines, Université de Lyon, CNRS, Lyon, France
- Groupe sur l’Immunité des Muqueuses et Agents Pathogènes, EA3064, Faculté de Médecine Jacques Lisfranc, Université de Lyon, Saint-Etienne, France
| | - Capucine Phelip
- Colloidal Vectors and Tissue Transport, UMR5305, Institut de Biologie et Chimie des Protéines, Université de Lyon, CNRS, Lyon, France
| | - Blandine Chanut
- Groupe sur l’Immunité des Muqueuses et Agents Pathogènes, EA3064, Faculté de Médecine Jacques Lisfranc, Université de Lyon, Saint-Etienne, France
| | - Laura Bulens-Grassigny
- Colloidal Vectors and Tissue Transport, UMR5305, Institut de Biologie et Chimie des Protéines, Université de Lyon, CNRS, Lyon, France
- Retroviruses and Structural Biochemistry, UMR5086, Institut de Biologie et Chimie des Protéines, Université de Lyon, CNRS, Lyon, France
| | - Fabienne Jospin
- Groupe sur l’Immunité des Muqueuses et Agents Pathogènes, EA3064, Faculté de Médecine Jacques Lisfranc, Université de Lyon, Saint-Etienne, France
| | - Christophe Guillon
- Retroviruses and Structural Biochemistry, UMR5086, Institut de Biologie et Chimie des Protéines, Université de Lyon, CNRS, Lyon, France
- *Correspondence: Christophe Guillon,
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Doležal M, Zábranský A, Dostál J, Vaněk O, Brynda J, Lepšík M, Hadravová R, Pichová I. Myristoylation drives dimerization of matrix protein from mouse mammary tumor virus. Retrovirology 2016; 13:2. [PMID: 26728401 PMCID: PMC4700671 DOI: 10.1186/s12977-015-0235-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/22/2015] [Indexed: 11/25/2022] Open
Abstract
Background Myristoylation of the matrix (MA) domain mediates the transport and binding of Gag polyproteins to the plasma membrane (PM) and is required for the assembly of most retroviruses. In betaretroviruses, which assemble immature particles in the cytoplasm, myristoylation is dispensable for assembly but is crucial for particle transport to the PM. Oligomerization of HIV-1 MA stimulates the transition of the myristoyl group from a sequestered to an exposed conformation, which is more accessible for membrane binding. However, for other retroviruses, the effect of MA oligomerization on myristoyl group exposure has not been thoroughly investigated. Results Here, we demonstrate that MA from the betaretrovirus mouse mammary tumor virus (MMTV) forms dimers in solution and that this process is stimulated by its myristoylation. The crystal structure of N-myristoylated MMTV MA, determined at 1.57 Å resolution, revealed that the myristoyl groups are buried in a hydrophobic pocket at the dimer interface and contribute to dimer formation. Interestingly, the myristoyl groups in the dimer are mutually swapped to achieve energetically stable binding, as documented by molecular dynamics modeling. Mutations within the myristoyl binding site resulted in reduced MA dimerization and extracellular particle release. Conclusions Based on our experimental, structural, and computational data, we propose a model for dimerization of MMTV MA in which myristoyl groups stimulate the interaction between MA molecules. Moreover, dimer-forming MA molecules adopt a sequestered conformation with their myristoyl groups entirely buried within the interaction interface. Although this differs from the current model proposed for lentiviruses, in which oligomerization of MA triggers exposure of myristoyl group, it appears convenient for intracellular assembly, which involves no apparent membrane interaction and allows the myristoyl group to be sequestered during oligomerization. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0235-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michal Doležal
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10, Prague, Czech Republic.
| | - Aleš Zábranský
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10, Prague, Czech Republic.
| | - Jiří Dostál
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10, Prague, Czech Republic.
| | - Ondřej Vaněk
- Department of Biochemistry, Faculty of Science, Charles University in Prague, Hlavova 8, 128 40, Prague, Czech Republic.
| | - Jiří Brynda
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10, Prague, Czech Republic.
| | - Martin Lepšík
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10, Prague, Czech Republic.
| | - Romana Hadravová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10, Prague, Czech Republic.
| | - Iva Pichová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo nám. 2, 166 10, Prague, Czech Republic.
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Biochemical evidence of a role for matrix trimerization in HIV-1 envelope glycoprotein incorporation. Proc Natl Acad Sci U S A 2015; 113:E182-90. [PMID: 26711999 DOI: 10.1073/pnas.1516618113] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The matrix (MA) domain of HIV Gag has important functions in directing the trafficking of Gag to sites of assembly and mediating the incorporation of the envelope glycoprotein (Env) into assembling particles. HIV-1 MA has been shown to form trimers in vitro; however, neither the presence nor the role of MA trimers has been documented in HIV-1 virions. We developed a cross-linking strategy to reveal MA trimers in virions of replication-competent HIV-1. By mutagenesis of trimer interface residues, we demonstrated a correlation between loss of MA trimerization and loss of Env incorporation. Additionally, we found that truncating the long cytoplasmic tail of Env restores incorporation of Env into MA trimer-defective particles, thus rescuing infectivity. We therefore propose a model whereby MA trimerization is required to form a lattice capable of accommodating the long cytoplasmic tail of HIV-1 Env; in the absence of MA trimerization, Env is sterically excluded from the assembling particle. These findings establish MA trimerization as an obligatory step in the assembly of infectious HIV-1 virions. As such, the MA trimer interface may represent a novel drug target for the development of antiretrovirals.
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Brown LA, Cox C, Baptiste J, Summers H, Button R, Bahlow K, Spurrier V, Kyser J, Luttge BG, Kuo L, Freed EO, Summers MF. NMR structure of the myristylated feline immunodeficiency virus matrix protein. Viruses 2015; 7:2210-29. [PMID: 25941825 PMCID: PMC4452903 DOI: 10.3390/v7052210] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 03/30/2015] [Accepted: 04/21/2015] [Indexed: 11/25/2022] Open
Abstract
Membrane targeting by the Gag proteins of the human immunodeficiency viruses (HIV types-1 and -2) is mediated by Gag's N-terminally myristylated matrix (MA) domain and is dependent on cellular phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2]. To determine if other lentiviruses employ a similar membrane targeting mechanism, we initiated studies of the feline immunodeficiency virus (FIV), a widespread feline pathogen with potential utility for development of human therapeutics. Bacterial co-translational myristylation was facilitated by mutation of two amino acids near the amino-terminus of the protein (Q5A/G6S; myrMAQ5A/G6S). These substitutions did not affect virus assembly or release from transfected cells. NMR studies revealed that the myristyl group is buried within a hydrophobic pocket in a manner that is structurally similar to that observed for the myristylated HIV-1 protein. Comparisons with a recent crystal structure of the unmyristylated FIV protein [myr(-)MA] indicate that only small changes in helix orientation are required to accommodate the sequestered myr group. Depletion of PI(4,5)P2 from the plasma membrane of FIV-infected CRFK cells inhibited production of FIV particles, indicating that, like HIV, FIV hijacks the PI(4,5)P2 cellular signaling system to direct intracellular Gag trafficking during virus assembly.
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Affiliation(s)
- Lola A Brown
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
| | - Cassiah Cox
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
| | - Janae Baptiste
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
| | - Holly Summers
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
| | - Ryan Button
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
| | - Kennedy Bahlow
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
| | - Vaughn Spurrier
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
| | - Jenna Kyser
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
| | - Benjamin G Luttge
- Virus-Cell Interaction Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, MD 21702-1201, USA.
| | - Lillian Kuo
- Virus-Cell Interaction Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, MD 21702-1201, USA.
| | - Eric O Freed
- Virus-Cell Interaction Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, MD 21702-1201, USA.
| | - Michael F Summers
- Howard Hughes Medical Institute, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
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