1
|
Aryal CM, Pan J. Probing the interactions of the HIV-1 matrix protein-derived polybasic region with lipid bilayers: insights from AFM imaging and force spectroscopy. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2024; 53:57-67. [PMID: 38172352 DOI: 10.1007/s00249-023-01697-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/18/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024]
Abstract
The human immunodeficiency virus type 1 (HIV-1) matrix protein contains a highly basic region, MA-HBR, crucial for various stages of viral replication. To elucidate the interactions between the polybasic peptide MA-HBR and lipid bilayers, we employed liquid-based atomic force microscopy (AFM) imaging and force spectroscopy on lipid bilayers of differing compositions. In 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayers, AFM imaging revealed the formation of annulus-shaped protrusions upon exposure to the polybasic peptide, accompanied by distinctive mechanical responses characterized by enhanced bilayer puncture forces. Importantly, our AFM-based force spectroscopy measurements unveiled that MA-HBR induces interleaflet decoupling within the cohesive bilayer organization. This is evidenced by a force discontinuity observed within the bilayer's elastic deformation regime. In POPC/cholesterol bilayers, MA-HBR caused similar yet smaller annular protrusions, demonstrating an intriguing interplay with cholesterol-rich membranes. In contrast, in bilayers containing anionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS) lipids, MA-HBR induced unique annular protrusions, granular nanoparticles, and nanotubules, showcasing its distinctive effects in anionic lipid-enriched environments. Notably, our force spectroscopy data revealed that anionic POPS lipids weakened interleaflet adhesion within the bilayer, resulting in interleaflet decoupling, which potentially contributes to the specific bilayer perturbations induced by MA-HBR. Collectively, our findings highlight the remarkable variations in how the polybasic peptide, MA-HBR, interacts with lipid bilayers of differing compositions, shedding light on its role in host membrane restructuring during HIV-1 infection.
Collapse
Affiliation(s)
- Chinta M Aryal
- Department of Physics, University of South Florida, Tampa, FL, 33620, USA
- , 2920 Burnet Ave Apt 3, Cincinnati, OH, 45219, USA
| | - Jianjun Pan
- Department of Physics, University of South Florida, Tampa, FL, 33620, USA.
| |
Collapse
|
2
|
Socas L, Ambroggio E. HIV-1 Gag specificity for PIP2 is regulated by macromolecular electric properties of both protein and membrane local environments. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - BIOMEMBRANES 2023; 1865:184157. [PMID: 37028700 DOI: 10.1016/j.bbamem.2023.184157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 03/14/2023] [Accepted: 03/29/2023] [Indexed: 04/08/2023]
Abstract
HIV-1 assembly occurs at the plasma membrane, with the Gag polyprotein playing a crucial role. Gag association with the membrane is directed by the matrix domain (MA), which is myristoylated and has a highly basic region that interacts with anionic lipids. Several pieces of evidence suggest that the presence of phosphatidylinositol-(4,5)-bisphosphate (PIP2) highly influences this binding. Furthermore, MA also interacts with nucleic acids, which is proposed to be important for the specificity of GAG for PIP2-containing membranes. It is hypothesized that RNA has a chaperone function by interacting with the MA domain, preventing Gag from associating with unspecific lipid interfaces. Here, we study the interaction of MA with monolayer and bilayer membrane systems, focusing on the specificity for PIP2 and on the possible effects of a Gag N-terminal peptide on impairing the binding for either RNA or membrane. We found that RNA decreases the kinetics of the protein association with lipid monolayers but has no effect on the selectivity for PIP2. Interestingly, for bilayer systems, this selectivity increases in presence of both the peptide and RNA, even for highly negatively charged compositions, where MA alone does not discriminate between membranes with or without PIP2. Therefore, we propose that the specificity of MA for PIP2-containing membranes might be related to the electrostatic properties of both membrane and protein local environments, rather than a simple difference in molecular affinities. This scenario provides a new understanding of the regulation mechanism, with a macromolecular view, rather than considering molecular interactions within a ligand-receptor model.
Collapse
|
3
|
Mona Sadat L, Seyed Mehdi S, Amitis R. HIV-1 Immune evasion: The main obstacle toward a successful vaccine. ACTA ACUST UNITED AC 2018. [DOI: 10.29328/journal.aaai.1001013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
4
|
Mu X, Fu Y, Zhu Y, Wang X, Xuan Y, Shang H, Goff SP, Gao G. HIV-1 Exploits the Host Factor RuvB-like 2 to Balance Viral Protein Expression. Cell Host Microbe 2015. [PMID: 26211835 DOI: 10.1016/j.chom.2015.06.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The correct ratio of the HIV-1 structural protein Gag to the envelope protein (Env) is important for maximal virion infectivity. How the virus ensures the production of Gag and Env proteins in an appropriate ratio remains unknown. We report that HIV-1 exploits the host factor RuvB-like 2 (RVB2) to balance relative expression of Gag and Env for efficient production of infectious virions. RVB2 inhibits Gag expression by interacting with both the encoded Matrix (MA) domain of Gag protein and 5' UTR of the translating mRNA and promoting mRNA degradation in a translation-dependent manner. This inhibitory activity of RVB2 is antagonized by Env through competitive interaction with MA, allowing Gag synthesis to proceed when Env levels are adequate for virion assembly. In HIV-1-positive patients, RVB2 levels positively correlate with viral loads and disease progression status. These findings reveal a mechanism by which HIV-1 regulates its protein expression.
Collapse
Affiliation(s)
- Xin Mu
- CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yajing Fu
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, The First Affiliated Hospital, China Medical University, Shenyang 110001, China
| | - Yiping Zhu
- Department of Biochemistry and Molecular Biophysics, Department of Microbiology and Immunology, and Howard Hughes Medical Institute, Columbia University Medical Center, Columbia University, New York NY, 10032, USA
| | - Xinlu Wang
- CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yifang Xuan
- CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Hong Shang
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, The First Affiliated Hospital, China Medical University, Shenyang 110001, China
| | - Stephen P Goff
- Department of Biochemistry and Molecular Biophysics, Department of Microbiology and Immunology, and Howard Hughes Medical Institute, Columbia University Medical Center, Columbia University, New York NY, 10032, USA
| | - Guangxia Gao
- CAS Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| |
Collapse
|
5
|
Selective acquisition of host-derived ICAM-1 by HIV-1 is a matrix-dependent process. J Virol 2014; 89:323-36. [PMID: 25320314 DOI: 10.1128/jvi.02701-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED HIV-1 acquires an impressive number of foreign components during its formation. Despite all previous efforts spent studying the nature and functionality of virus-anchored host molecules, the exact mechanism(s) through which such constituents are acquired by HIV-1 is still unknown. However, in the case of ICAM-1, one of the most extensively studied transmembrane proteins found associated with mature virions, the Pr55(Gag) precursor polyprotein appears to be a potential interaction partner. We investigated and characterized at the molecular level the process of ICAM-1 incorporation using initially a Pr55(Gag)-based virus-like particle (VLP) model. Substitution of various domains of Pr55(Gag), such as the nucleocapsid, SP2, or p6, had no effect on the acquisition of ICAM-1. We found that the structural matrix protein (MA) is mandatory for ICAM-1 incorporation within VLPs, and we confirmed this novel observation with the replication-competent HIV-1 molecular clone NL4.3. Additional studies suggest that the C-terminal two-thirds of MA, and especially 13 amino acids positioned inside the fifth α-helix, are important. Moreover, based on three-dimensional (3D) modeling of protein-protein interactions (i.e., protein-protein docking) and further validation by a virus capture assay, we found that a series of acidic residues in the MA domain interact with basic amino acids located in the ICAM-1 cytoplasmic tail. Our findings provide new insight into the molecular mechanism governing the acquisition of ICAM-1, a host molecule known to enhance HIV-1 infectivity in a significant manner. Altogether, these observations offer a new avenue for the development of antiviral therapeutics that are directed at a target of host origin. IMPORTANCE Intercellular adhesion molecule 1 (ICAM-1) is a cell surface host component known to be efficiently inserted within emerging HIV-1 particles. It has been demonstrated that host-derived ICAM-1 molecules act as a strong attachment factor and increase HIV-1 infectivity substantially. Despite previous efforts spent studying virus-associated host molecules, the precise mechanism(s) through which such constituents are inserted within emerging HIV-1 particles still remains obscure. Previous data suggest that the Pr55(Gag) precursor polyprotein appears as a potential interaction partner with ICAM-1. In the present study, we demonstrate that the HIV-1 matrix domain plays a key role in the ICAM-1 incorporation process. Some observations were confirmed with whole-virus preparations amplified in primary human cells, thereby providing physiological significance to our data.
Collapse
|
6
|
Segura MM, Mangion M, Gaillet B, Garnier A. New developments in lentiviral vector design, production and purification. Expert Opin Biol Ther 2013; 13:987-1011. [PMID: 23590247 DOI: 10.1517/14712598.2013.779249] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Lentiviruses are a very potent class of viral vectors for which there is presently a rapidly growing interest for a number of gene therapy. However, their construction, production and purification need to be performed according to state-of-the-art techniques in order to obtain sufficient quantities of high purity material of any usefulness and safety. AREAS COVERED The recent advances in the field of recombinant lentivirus vector design, production and purification will be reviewed with an eye toward its utilization for gene therapy. Such a review should be helpful for the potential user of this technology. EXPERT OPINION The principal hurdles toward the use of recombinant lentivirus as a gene therapy vector are the low titer at which it is produced as well as the difficulty to purify it at an acceptable level without degrading it. The recent advances in the bioproduction of this vector suggest these issues are about to be resolved, making the retrovirus gene therapy a mature technology.
Collapse
Affiliation(s)
- Maria Mercedes Segura
- Chemical Engineering Department, Universitat Autònoma de Barcelona, Campus Bellaterra, Cerdanyola del Vallès (08193), Barcelona, Spain
| | | | | | | |
Collapse
|
7
|
Schönichen A, Webb BA, Jacobson MP, Barber DL. Considering protonation as a posttranslational modification regulating protein structure and function. Annu Rev Biophys 2013; 42:289-314. [PMID: 23451893 DOI: 10.1146/annurev-biophys-050511-102349] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Posttranslational modification is an evolutionarily conserved mechanism for regulating protein activity, binding affinity, and stability. Compared with established posttranslational modifications such as phosphorylation or ubiquitination, posttranslational modification by protons within physiological pH ranges is a less recognized mechanism for regulating protein function. By changing the charge of amino acid side chains, posttranslational modification by protons can drive dynamic changes in protein conformation and function. Addition and removal of a proton is rapid and reversible and, in contrast to most other posttranslational modifications, does not require an enzyme. Signaling specificity is achieved by only a minority of sites in proteins titrating within the physiological pH range. Here, we examine the structural mechanisms and functional consequences of proton posttranslational modification of pH-sensing proteins regulating different cellular processes.
Collapse
Affiliation(s)
- André Schönichen
- Department of Cell and Tissue Biology, University of California, San Francisco, USA
| | | | | | | |
Collapse
|
8
|
Bugatti A, Giagulli C, Urbinati C, Caccuri F, Chiodelli P, Oreste P, Fiorentini S, Orro A, Milanesi L, D'Ursi P, Caruso A, Rusnati M. Molecular interaction studies of HIV-1 matrix protein p17 and heparin: identification of the heparin-binding motif of p17 as a target for the development of multitarget antagonists. J Biol Chem 2012; 288:1150-61. [PMID: 23166320 DOI: 10.1074/jbc.m112.400077] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Once released by HIV(+) cells, p17 binds heparan sulfate proteoglycans (HSPGs) and CXCR1 on leukocytes causing their dysfunction. By exploiting an approach integrating computational modeling, site-directed mutagenesis of p17, chemical desulfation of heparin, and surface plasmon resonance, we characterized the interaction of p17 with heparin, a HSPG structural analog, and CXCR1. p17 binds to heparin with an affinity (K(d) = 190 nm) that is similar to those of other heparin-binding viral proteins. Two stretches of basic amino acids (basic motifs) are present in p17 N and C termini. Neutralization (Arg→Ala substitution) of the N-terminal, but not of the C-terminal basic motif, causes the loss of p17 heparin-binding capacity. The N-terminal heparin-binding motif of p17 partially overlaps the CXCR1-binding domain. Accordingly, its neutralization prevents also p17 binding to the chemochine receptor. Competition experiments demonstrated that free heparin and heparan sulfate (HS), but not selectively 2-O-, 6-O-, and N-O desulfated heparins, prevent p17 binding to substrate-immobilized heparin, indicating that the sulfate groups of the glycosaminoglycan mediate p17 interaction. Evaluation of the p17 antagonist activity of a panel of biotechnological heparins derived by chemical sulfation of the Escherichia coli K5 polysaccharide revealed that the highly N,O-sulfated derivative prevents the binding of p17 to both heparin and CXCR1, thus inhibiting p17-driven chemotactic migration of human monocytes with an efficiency that is higher than those of heparin and HS. Here, we characterized at a molecular level the interaction of p17 with its cellular receptors, laying the basis for the development of heparin-mimicking p17 antagonists.
Collapse
Affiliation(s)
- Antonella Bugatti
- Section of Experimental Oncology and Immunology, School of Medicine, University of Brescia, Brescia 25123, Italy
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Bibollet-Ruche F, Heigele A, Keele BF, Easlick JL, Decker JM, Takehisa J, Learn G, Sharp PM, Hahn BH, Kirchhoff F. Efficient SIVcpz replication in human lymphoid tissue requires viral matrix protein adaptation. J Clin Invest 2012; 122:1644-52. [PMID: 22505456 DOI: 10.1172/jci61429] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 03/05/2012] [Indexed: 12/20/2022] Open
Abstract
SIVs infecting wild-living apes in west central Africa have crossed the species barrier to humans on at least four different occasions, one of which spawned the AIDS pandemic. Although the chimpanzee precursor of pandemic HIV-1 strains must have been able to infect humans, the capacity of SIVcpz strains to replicate in human lymphoid tissues (HLTs) is not known. Here, we show that SIVcpz strains from two chimpanzee subspecies are capable of replicating in human tonsillary explant cultures, albeit only at low titers. However, SIVcpz replication in HLT was significantly improved after introduction of a previously identified human-specific adaptation at position 30 in the viral Gag matrix protein. An Arg or Lys at this position significantly increased SIVcpz replication in HLT, while the same mutation reduced viral replication in chimpanzee-derived CD4(+) T cells. Thus, naturally occurring SIVcpz strains are capable of infecting HLTs, the major site of HIV-1 replication in vivo. However, efficient replication requires the acquisition of a host-specific adaptation in the viral matrix protein. These results identify Gag matrix as a major determinant of SIVcpz replication fitness in humans and suggest a critical role in the emergence of HIV/AIDS.
Collapse
Affiliation(s)
- Frederic Bibollet-Ruche
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6060, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
HIV cell-to-cell transmission requires the production of infectious virus particles and does not proceed through env-mediated fusion pores. J Virol 2012; 86:3924-33. [PMID: 22258237 DOI: 10.1128/jvi.06478-11] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Direct cell-to-cell transmission of human immunodeficiency virus (HIV) is a more potent and efficient means of virus propagation than infection by cell-free virus particles. The aim of this study was to determine whether cell-to-cell transmission requires the assembly of enveloped virus particles or whether nucleic acids with replication potential could translocate directly from donor to target cells through envelope glycoprotein (Env)-induced fusion pores. To this end, we characterized the transmission properties of viruses carrying mutations in the matrix protein (MA) that affect the incorporation of Env into virus particles but do not interfere with Env-mediated cell-cell fusion. By use of cell-free virus, the infectivity of MA mutant viruses was below the detection threshold both in single-cycle and in multiple-cycle assays. Truncation of the cytoplasmic tail (CT) of Env restored the incorporation of Env into MA mutant viruses and rescued their cell-free infectivity to different extents. In cell-to-cell transmission assays, MA mutations prevented HIV transmission from donor to target cells, despite efficient Env-dependent membrane fusion. HIV transmission was blocked at the level of virus core translocation into the cytosol of target cells. As in cell-free assays, rescue of Env incorporation by truncation of the Env CT restored the virus core translocation and cell-to-cell infectivity of MA mutant viruses. These data show that HIV cell-to-cell transmission requires the assembly of enveloped virus particles. The increased efficiency of this infection route may thus be attributed to the high local concentrations of virus particles at sites of cellular contacts rather than to a qualitatively different transmission process.
Collapse
|
11
|
Chukkapalli V, Ono A. Molecular determinants that regulate plasma membrane association of HIV-1 Gag. J Mol Biol 2011; 410:512-24. [PMID: 21762797 DOI: 10.1016/j.jmb.2011.04.015] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 04/04/2011] [Accepted: 04/06/2011] [Indexed: 11/17/2022]
Abstract
Human immunodeficiency virus type 1 assembly is a multistep process that occurs at the plasma membrane (PM). Targeting and binding of Gag to the PM are the first steps in this assembly process and are mediated by the matrix domain of Gag. This review highlights our current knowledge on viral and cellular determinants that affect specific interactions between Gag and the PM. We will discuss potential mechanisms by which the matrix domain might integrate three regulatory components, myristate, phosphatidylinositol-(4,5)-bisphosphate, and RNA, to ensure that human immunodeficiency virus type 1 assembly occurs at the PM.
Collapse
Affiliation(s)
- Vineela Chukkapalli
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | | |
Collapse
|
12
|
Giroud C, Chazal N, Briant L. Cellular kinases incorporated into HIV-1 particles: passive or active passengers? Retrovirology 2011; 8:71. [PMID: 21888651 PMCID: PMC3182982 DOI: 10.1186/1742-4690-8-71] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 09/02/2011] [Indexed: 11/10/2022] Open
Abstract
Phosphorylation is one of the major mechanisms by which the activities of protein factors can be regulated. Such regulation impacts multiple key-functions of mammalian cells, including signal transduction, nucleo-cytoplasmic shuttling, macromolecular complexes assembly, DNA binding and regulation of enzymatic activities to name a few. To ensure their capacities to replicate and propagate efficiently in their hosts, viruses may rely on the phosphorylation of viral proteins to assist diverse steps of their life cycle. It has been known for several decades that particles from diverse virus families contain some protein kinase activity. While large DNA viruses generally encode for viral kinases, RNA viruses and more precisely retroviruses have acquired the capacity to hijack the signaling machinery of the host cell and to embark cellular kinases when budding. Such property was demonstrated for HIV-1 more than a decade ago. This review summarizes the knowledge acquired in the field of HIV-1-associated kinases and discusses their possible function in the retroviral life cycle.
Collapse
Affiliation(s)
- Charline Giroud
- Centre d'Études d'Agents Pathogènes et Biotechnologies pour la Santé, UMR5236 CNRS - Université Montpellier 1-Montpellier 2, Montpellier, France
| | | | | |
Collapse
|
13
|
Assembly and replication of HIV-1 in T cells with low levels of phosphatidylinositol-(4,5)-bisphosphate. J Virol 2011; 85:3584-95. [PMID: 21270152 DOI: 10.1128/jvi.02266-10] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
HIV-1 Gag assembles into virus particles predominantly at the plasma membrane (PM). Previously, we observed that phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P(2)] is essential for Gag binding to the plasma membrane and virus release in HeLa cells. In the current study, we found that PI(4,5)P(2) also facilitates Gag binding to the PM and efficient virus release in T cells. Notably, serial passage of HIV-1 in an A3.01 clone that expresses polyphosphoinositide 5-phosphatase IV (5ptaseIV), which depletes cellular PI(4,5)P(2), yielded an adapted mutant with a Leu-to-Arg change at matrix residue 74 (74LR). Virus replication in T cells expressing 5ptaseIV was accelerated by the 74LR mutation relative to replication of wild type HIV-1 (WT). This accelerated replication of the 74LR mutant was not due to improved virus release. In control T cells, the 74LR mutant releases virus less efficiently than does the WT, whereas in cells expressing 5ptaseIV, the WT and the 74LR mutant are similarly inefficient in virus release. Unexpectedly, we found that the 74LR mutation increased virus infectivity and compensated for the inefficient virus release. Altogether, these results indicate that PI(4,5)P(2) is essential for Gag-membrane binding, targeting of Gag to the PM, and efficient virus release in T cells, which in turn likely promotes efficient virus spread in T cell cultures. In T cells with low PI(4,5)P(2) levels, however, the reduced virus particle production can be compensated for by a mutation that enhances virus infectivity.
Collapse
|
14
|
Cai M, Huang Y, Craigie R, Clore GM. Structural basis of the association of HIV-1 matrix protein with DNA. PLoS One 2010; 5:e15675. [PMID: 21203471 PMCID: PMC3009736 DOI: 10.1371/journal.pone.0015675] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Accepted: 11/21/2010] [Indexed: 12/31/2022] Open
Abstract
HIV-1 matrix (MA) is a multifunctional protein that is synthesized as a polyprotein that is cleaved by protease during viral maturation. MA contains a cluster of basic residues whose role is controversial. Proposed functions include membrane anchoring, facilitating viral assembly, and directing nuclear import of the viral DNA. Since MA has been reported to be a component of the preintegration complex (PIC), we have used NMR to probe its interaction with other PIC components. We show that MA interacts with DNA and this is likely sufficient to account for its association with the PIC.
Collapse
Affiliation(s)
- Mengli Cai
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ying Huang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Robert Craigie
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| |
Collapse
|
15
|
Aoki T, Shimizu S, Urano E, Futahashi Y, Hamatake M, Tamamura H, Terashima K, Murakami T, Yamamoto N, Komano J. Improvement of lentiviral vector-mediated gene transduction by genetic engineering of the structural protein Pr55 Gag. Gene Ther 2010; 17:1124-33. [PMID: 20410927 DOI: 10.1038/gt.2010.61] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The lentiviral vector is a promising tool for human gene therapy because of its ability to transduce genes into many cell types. However, one of the technical problems associated with the lentiviral vector is that lentiviral titers in current production systems are relatively low compared with the other viral vectors. In this study, we provide genetic evidence that the attachment of heterologous myristoylation (myr) signals on the amino-terminus of human immunodeficiency virus type 1 Pr55(Gag) (Gag) can increase the viral yield up to 10-fold, leading to the enhancement of gene transduction in many cell lines. The myr signal Gag constructs behaved similarly to the wild-type Gag in targeting to detergent-resistant membrane compartments, Vps4-dependence for viral budding, and virion morphology. However, the myr signal Gag constructs showed improved oligomerization efficiency as measured by bioluminescence resonance energy transfer in living cells, contributing to increased viral production and efficient activation of the viral protease responsible for virion maturation. The genetically modified Gag represents the next generation lentiviral vector, and should contribute to the success of many lentiviral vector applications.
Collapse
Affiliation(s)
- T Aoki
- AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Opposing mechanisms involving RNA and lipids regulate HIV-1 Gag membrane binding through the highly basic region of the matrix domain. Proc Natl Acad Sci U S A 2010; 107:1600-5. [PMID: 20080620 DOI: 10.1073/pnas.0908661107] [Citation(s) in RCA: 182] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Membrane binding of Gag, a crucial step in HIV-1 assembly, is facilitated by bipartite signals within the matrix (MA) domain: N-terminal myristoyl moiety and the highly basic region (HBR). We and others have shown that Gag interacts with a plasma-membrane-specific acidic phospholipid, phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P(2)], via the HBR, and that this interaction is important for efficient membrane binding and plasma membrane targeting of Gag. Generally, in protein-PI(4,5)P(2) interactions, basic residues promote the interaction as docking sites for the acidic headgroup of the lipid. In this study, toward better understanding of the Gag-PI(4,5)P(2) interaction, we sought to determine the roles played by all of the basic residues in the HBR. We identified three basic residues promoting PI(4,5)P(2)-dependent Gag-membrane binding. Unexpectedly, two other HBR residues, Lys25 and Lys26, suppress membrane binding in the absence of PI(4,5)P(2) and prevent promiscuous intracellular localization of Gag. This inhibition of nonspecific membrane binding is likely through suppression of myristate-dependent hydrophobic interaction because mutating Lys25 and Lys26 enhances binding of Gag with neutral-charged liposomes. These residues were reported to bind RNA. Importantly, we found that RNA also negatively regulates Gag membrane binding. In the absence but not presence of PI(4,5)P(2), RNA bound to MA HBR abolishes Gag-liposome binding. Altogether, these data indicate that the HBR is unique among basic phosphoinositide-binding domains, because it integrates three regulatory components, PI(4,5)P(2), myristate, and RNA, to ensure plasma membrane specificity for particle assembly.
Collapse
|
17
|
Du Y, Zuckermann FA, Yoo D. Myristoylation of the small envelope protein of porcine reproductive and respiratory syndrome virus is non-essential for virus infectivity but promotes its growth. Virus Res 2009; 147:294-9. [PMID: 19951726 PMCID: PMC7114369 DOI: 10.1016/j.virusres.2009.11.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 11/23/2009] [Accepted: 11/25/2009] [Indexed: 11/26/2022]
Abstract
The small envelope (E) protein of porcine reproductive and respiratory syndrome virus (PRRSV) is known to possess the properties of an ion-channel protein, and in the present study we show that the PRRSV E protein is N-terminal myristoylated. The PRRSV E protein contains the consensus motif of 1MGxxxS6 for myristoylation, and in the presence of 2-hydroxymyristic acid, the virus titer decreased by 2.5 log TCID50 and the level of viral RNA was reduced significantly. When the glycine at position 2 was mutated to alanine (G2A) using an infectious cDNA clone, a viable virus was recoverable and a mutant PRRSV was obtained. The titers of G2A mutant virus were 2.0 × 104 and 1.0 × 106 TCID50/ml for ‘passage-2’ and ‘passage-3’ viruses, respectively, in PAM cells, and these titers were significantly lower than those of wild-type PRRSV. When treated with the myristoylation inhibitor, the G2A mutant virus was resistant to the drug. The data show that the PRRSV E protein myristoylation is non-essential for PRRSV infectivity but promotes the growth of the virus.
Collapse
Affiliation(s)
- Yijun Du
- Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Ave, Urbana, IL 61802, USA
| | | | | |
Collapse
|
18
|
Thaa B, Kabatek A, Zevenhoven-Dobbe JC, Snijder EJ, Herrmann A, Veit M. Myristoylation of the arterivirus E protein: the fatty acid modification is not essential for membrane association but contributes significantly to virus infectivity. J Gen Virol 2009; 90:2704-2712. [DOI: 10.1099/vir.0.011957-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The envelope of equine arteritis virus (EAV) contains two glycoprotein complexes (GP2b/GP3/GP4 and GP5/M) and the small, non-glycosylated E protein. As E is essential for the production of infectious progeny but dispensable for assembly and release of virus-like particles, it probably mediates virus entry into cells, putatively in concert with the GP2b/GP3/GP4 complex. The E protein contains a central hydrophobic domain and a conserved potential site for N-terminal myristoylation, a hydrophobic modification usually pivotal for membrane targeting of the modified protein. Here, it was shown by radiolabelling that E is myristoylated at glycine-2, both in transfected cells as a fusion protein with yellow fluorescent protein (YFP) and in virus particles. Biochemical fractionation revealed that E–YFP with an inactivated acylation site was still completely membrane-bound, indicating that the putative transmembrane domain of E mediates membrane targeting. Confocal microscopy showed that both myristoylated and non-myristoylated E–YFP were localized to the endoplasmic reticulum and Golgi complex, the membranes from which EAV buds. The presence of a myristoylation inhibitor during replication of EAV, whilst completely blocking E acylation, reduced virus titres by 1.5 log10. Similarly, a mutant EAV with non-myristoylatable E grew to a titre five- to sevenfold lower than that of the wild-type virus and exhibited a reduced plaque size. Western blotting of cell-culture supernatants showed that N and M, the major structural proteins of EAV, are released in similar amounts by cells transfected with wild-type and mutant genomes. Thus, E myristoylation is not required for budding of particles and probably has a function during virus entry.
Collapse
Affiliation(s)
- Bastian Thaa
- Department of Immunology and Molecular Biology Veterinary Faculty, Free University, Berlin, Germany
| | - Aleksander Kabatek
- Department of Immunology and Molecular Biology Veterinary Faculty, Free University, Berlin, Germany
| | - Jessika C. Zevenhoven-Dobbe
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, The Netherlands
| | - Eric J. Snijder
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, The Netherlands
| | - Andreas Herrmann
- Department of Biology, Molecular Biophysics, Humboldt University, Berlin, Germany
| | - Michael Veit
- Department of Immunology and Molecular Biology Veterinary Faculty, Free University, Berlin, Germany
| |
Collapse
|
19
|
Urano E, Aoki T, Futahashi Y, Murakami T, Morikawa Y, Yamamoto N, Komano J. Substitution of the myristoylation signal of human immunodeficiency virus type 1 Pr55Gag with the phospholipase C-delta1 pleckstrin homology domain results in infectious pseudovirion production. J Gen Virol 2009; 89:3144-3149. [PMID: 19008404 PMCID: PMC2885030 DOI: 10.1099/vir.0.2008/004820-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The matrix domain (MA) of human immunodeficiency virus type 1 Pr55Gag is covalently modified with a myristoyl group that mediates efficient viral production. However, the role of myristoylation, particularly in the viral entry process, remains uninvestigated. This study replaced the myristoylation signal of MA with a well-studied phosphatidylinositol 4,5-biphosphate-binding plasma membrane (PM) targeting motif, the phospholipase C-delta1 pleckstrin homology (PH) domain. PH-Gag-Pol PM targeting and viral production efficiencies were improved compared with Gag-Pol, consistent with the estimated increases in Gag-PM affinity. Both virions were recovered in similar sucrose density-gradient fractions and had similar mature virion morphologies. Importantly, PH-Gag-Pol and Gag-Pol pseudovirions had almost identical infectivity, suggesting a dispensable role for myristoylation in the virus life cycle. PH-Gag-Pol might be useful in separating the myristoylation-dependent processes from the myristoylation-independent processes. This the first report demonstrating infectious pseudovirion production without myristoylated Pr55Gag.
Collapse
Affiliation(s)
- Emiko Urano
- Kitasato Institute of Life Sciences, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan.,AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Toru Aoki
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Yuko Futahashi
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Tsutomu Murakami
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Yuko Morikawa
- Kitasato Institute of Life Sciences, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan
| | - Naoki Yamamoto
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Jun Komano
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| |
Collapse
|
20
|
Graham SC, Assenberg R, Delmas O, Verma A, Gholami A, Talbi C, Owens RJ, Stuart DI, Grimes JM, Bourhy H. Rhabdovirus matrix protein structures reveal a novel mode of self-association. PLoS Pathog 2008; 4:e1000251. [PMID: 19112510 PMCID: PMC2603668 DOI: 10.1371/journal.ppat.1000251] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Accepted: 12/01/2008] [Indexed: 01/18/2023] Open
Abstract
The matrix (M) proteins of rhabdoviruses are multifunctional proteins essential for virus maturation and budding that also regulate the expression of viral and host proteins. We have solved the structures of M from the vesicular stomatitis virus serotype New Jersey (genus: Vesiculovirus) and from Lagos bat virus (genus: Lyssavirus), revealing that both share a common fold despite sharing no identifiable sequence homology. Strikingly, in both structures a stretch of residues from the otherwise-disordered N terminus of a crystallographically adjacent molecule is observed binding to a hydrophobic cavity on the surface of the protein, thereby forming non-covalent linear polymers of M in the crystals. While the overall topology of the interaction is conserved between the two structures, the molecular details of the interactions are completely different. The observed interactions provide a compelling model for the flexible self-assembly of the matrix protein during virion morphogenesis and may also modulate interactions with host proteins.
Collapse
Affiliation(s)
- Stephen C Graham
- Division of Structural Biology and Oxford Protein Production Facility, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Goh GKM, Dunker AK, Uversky VN. A comparative analysis of viral matrix proteins using disorder predictors. Virol J 2008; 5:126. [PMID: 18947403 PMCID: PMC2579295 DOI: 10.1186/1743-422x-5-126] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2008] [Accepted: 10/23/2008] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND A previous study (Goh G.K.-M., Dunker A.K., Uversky V.N. (2008) Protein intrinsic disorder toolbox for comparative analysis of viral proteins. BMC Genomics. 9 (Suppl. 2), S4) revealed that HIV matrix protein p17 possesses especially high levels of predicted intrinsic disorder (PID). In this study, we analyzed the PID patterns in matrix proteins of viruses related and unrelated to HIV-1. RESULTS Both SIVmac and HIV-1 p17 proteins were predicted by PONDR VLXT to be highly disordered with subtle differences containing 50% and 60% disordered residues, respectively. SIVmac is very closely related to HIV-2. A specific region that is predicted to be disordered in HIV-1 is missing in SIVmac. The distributions of PID patterns seem to differ in SIVmac and HIV-1 p17 proteins. A high level of PID for the matrix does not seem to be mandatory for retroviruses, since Equine Infectious Anemia Virus (EIAV), an HIV cousin, has been predicted to have low PID level for the matrix; i.e. its matrix protein p15 contains only 21% PID residues. Surprisingly, the PID percentage and the pattern of predicted disorder distribution for p15 resemble those of the influenza matrix protein M1 (25%). CONCLUSION Our data might have important implications in the search for HIV vaccines since disorder in the matrix protein might provide a mechanism for immune evasion.
Collapse
Affiliation(s)
- Gerard Kian-Meng Goh
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | | | | |
Collapse
|
22
|
Cellular and molecular interactions in coinfection with hepatitis C virus and human immunodeficiency virus. Expert Rev Mol Med 2008; 10:e30. [PMID: 18928579 DOI: 10.1017/s1462399408000847] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is associated with increased HCV replication and a more rapid progression to severe liver disease, including the development of cirrhosis and hepatocellular carcinoma. In this review, we discuss the current understanding of the pathogenesis of HCV/HIV coinfection and the cellular and molecular mechanisms associated with the accelerated course of liver disease. The strength and breadth of HCV-specific T-cell responses are reduced in HCV/HIV-coinfected patients compared with those infected with HCV alone, suggesting that the immunosuppression induced by HIV compromises immune responses to HCV. HCV is not directly cytopathic, but many of the pathological changes observed in the liver of infected patients are a direct result of the intrahepatic antiviral immune responses. Apoptosis also has a role in HCV-mediated liver damage through the induction of apoptotic pathways involving the host immune response and HCV viral proteins. This review summarises the evidence correlating the role of cell-mediated immune responses and apoptosis with liver disease progression in HCV/HIV-coinfected patients.
Collapse
|