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Chagas BCA, Zhou X, Guerrero M, Ilina TV, Ishima R. Interplay between protease and reverse transcriptase dimerization in a model HIV-1 polyprotein. Protein Sci 2024; 33:e5080. [PMID: 38896002 DOI: 10.1002/pro.5080] [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: 02/12/2024] [Revised: 05/01/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024]
Abstract
The Gag-Pol polyprotein in human immunodeficiency virus type I (HIV-1) encodes enzymes that are essential for virus replication: protease (PR), reverse transcriptase (RT), and integrase (IN). The mature forms of PR, RT and IN are homodimer, heterodimer and tetramer, respectively. The precise mechanism underlying the formation of dimer or tetramer is not yet understood. Here, to gain insight into the dimerization of PR and RT in the precursor, we prepared a model precursor, PR-RT, incorporating an inactivating mutation at the PR active site, D25A, and including two residues in the p6* region, fused to a SUMO-tag, at the N-terminus of the PR region. We also prepared two mutants of PR-RT containing a dimer dissociation mutation either in the PR region, PR(T26A)-RT, or in the RT region, PR-RT(W401A). Size exclusion chromatography showed both monomer and dimer fractions in PR-RT and PR(T26A)-RT, but only monomer in PR-RT(W401A). SEC experiments of PR-RT in the presence of protease inhibitor, darunavir, significantly enhanced the dimerization. Additionally, SEC results suggest an estimated PR-RT dimer dissociation constant that is higher than that of the mature RT heterodimer, p66/p51, but slightly lower than the premature RT homodimer, p66/p66. Reverse transcriptase assays and RT maturation assays were performed as tools to assess the effects of the PR dimer-interface on these functions. Our results consistently indicate that the RT dimer-interface plays a crucial role in the dimerization in PR-RT, whereas the PR dimer-interface has a lesser role.
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Affiliation(s)
- Brisa Caroline Alves Chagas
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Xiaohong Zhou
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Michel Guerrero
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Tatiana V Ilina
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Rieko Ishima
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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2
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Maphumulo NF, Gordon ML. HIV-1 envelope facilitates the development of protease inhibitor resistance through acquiring mutations associated with viral entry and immune escape. Front Microbiol 2024; 15:1388729. [PMID: 38699474 PMCID: PMC11063367 DOI: 10.3389/fmicb.2024.1388729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 03/27/2024] [Indexed: 05/05/2024] Open
Abstract
Introduction There is increasing evidence supporting a role for HIV-1 envelope in the development of Protease Inhibitor drug resistance, and a recent report from our group suggested that Env mutations co-evolve with Gag-Protease mutations in the pathway to Lopinavir resistance. In this study, we investigated the effect of co-evolving Env mutations on virus function and structure. Methods Co-receptor usage and n-linked glycosylation were investigated using Geno2Pheno as well as tools available at the Los Alamos sequence database. Molecular dynamics simulations were performed using Amber 18 and analyzed using Cpptraj, and molecular interactions were calculated using the Ring server. Results The results showed that under Protease Inhibitor drug selection pressure, the envelope gene modulates viral entry by protecting the virus from antibody recognition through the increased length and number of N-glycosylation sites observed in V1/V2 and to some extent V5. Furthermore, gp120 mutations appear to modulate viral entry through a switch to the CXCR4 coreceptor, induced by higher charge in the V3 region and specific mutations at the coreceptor binding sites. In gp41, S534A formed a hydrogen bond with L602 found in the disulfide loop region between the Heptad Repeat 1 and Heptad Repeat 2 domains and could negatively affect the association of gp120-gp41 during viral entry. Lastly, P724Q/S formed both intermolecular and intramolecular interactions with residues within the Kennedy loop, a known epitope. Discussion In conclusion, the results suggest that mutations in envelope during Protease Inhibitor treatment failure are related to immune escape and that S534A mutants could preferentially use the cell-to-cell route of infection.
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Affiliation(s)
| | - Michele L. Gordon
- Department of Virology, Doris Duke Medical Research Institute, College of Health Sciences, University of KwaZulu-Natala, Durban, South Africa
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3
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Banerjee P, Qu K, Briggs JAG, Voth GA. Molecular dynamics simulations of HIV-1 matrix-membrane interactions at different stages of viral maturation. Biophys J 2024; 123:389-406. [PMID: 38196190 PMCID: PMC10870173 DOI: 10.1016/j.bpj.2024.01.006] [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: 09/25/2023] [Revised: 12/05/2023] [Accepted: 01/04/2024] [Indexed: 01/11/2024] Open
Abstract
Although the structural rearrangement of the membrane-bound matrix (MA) protein trimers upon HIV-1 maturation has been reported, the consequences of MA maturation on the MA-lipid interactions are not well understood. Long-timescale molecular dynamics simulations of the MA multimeric assemblies of immature and mature virus particles with our realistic asymmetric membrane model have explored MA-lipid interactions and lateral organization of lipids around MA complexes. The number of stable MA-phosphatidylserine and MA-phosphatidylinositol 4,5-bisphosphate (PIP2) interactions at the trimeric interface of the mature MA complex is observed to be greater compared to that of the immature MA complex. Our simulations identified an alternative PIP2-binding site in the immature MA complex where the multivalent headgroup of a PIP2 lipid with a greater negative charge binds to multiple basic amino acid residues such as ARG3 residues of both the MA monomers at the trimeric interface and highly basic region (HBR) residues (LYS29, LYS31) of one of the MA monomers. Our enhanced sampling simulations have explored the conformational space of phospholipids at different binding sites of the trimer-trimer interface of MA complexes that are not accessible by conventional unbiased molecular dynamics. Unlike the immature MA complex, the 2' acyl tail of two PIP2 lipids at the trimeric interface of the mature MA complex is observed to sample stable binding pockets of MA consisting of helix-4 residues. Together, our results provide molecular-level insights into the interactions of MA trimeric complexes with membrane and different lipid conformations at the specific binding sites of MA protein before and after viral maturation.
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Affiliation(s)
- Puja Banerjee
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois
| | - Kun Qu
- Infectious Diseases Translational Research Programme, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - John A G Briggs
- Department of Cell and Virus Structure, Max Planck Institute of Biochemistry, Planegg, Germany
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois.
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Hao M, Imamichi T, Chang W. Modeling and Analysis of HIV-1 Pol Polyprotein as a Case Study for Predicting Large Polyprotein Structures. Int J Mol Sci 2024; 25:1809. [PMID: 38339086 PMCID: PMC10855158 DOI: 10.3390/ijms25031809] [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: 12/29/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
Acquired immunodeficiency syndrome (AIDS) is caused by human immunodeficiency virus (HIV). HIV protease, reverse transcriptase, and integrase are targets of current drugs to treat the disease. However, anti-viral drug-resistant strains have emerged quickly due to the high mutation rate of the virus, leading to the demand for the development of new drugs. One attractive target is Gag-Pol polyprotein, which plays a key role in the life cycle of HIV. Recently, we found that a combination of M50I and V151I mutations in HIV-1 integrase can suppress virus release and inhibit the initiation of Gag-Pol autoprocessing and maturation without interfering with the dimerization of Gag-Pol. Additional mutations in integrase or RNase H domain in reverse transcriptase can compensate for the defect. However, the molecular mechanism is unknown. There is no tertiary structure of the full-length HIV-1 Pol protein available for further study. Therefore, we developed a workflow to predict the tertiary structure of HIV-1 NL4.3 Pol polyprotein. The modeled structure has comparable quality compared with the recently published partial HIV-1 Pol structure (PDB ID: 7SJX). Our HIV-1 NL4.3 Pol dimer model is the first full-length Pol tertiary structure. It can provide a structural platform for studying the autoprocessing mechanism of HIV-1 Pol and for developing new potent drugs. Moreover, the workflow can be used to predict other large protein structures that cannot be resolved via conventional experimental methods.
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Affiliation(s)
| | | | - Weizhong Chang
- Laboratory of Human Retrovirology and Immunoinformatics, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA; (M.H.); (T.I.)
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5
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Hossain MI, Asha AT, Hossain MA, Mahmud S, Chowdhury K, Mohiuddin RB, Nahar N, Sarker S, Napis S, Hossain MS, Mohiuddin A. Investigating the role of hypothetical protein (AAB33144.1) in HIV-1 virus pathogenicity: A comparative study with FDA-Approved inhibitor compounds through In silico analysis and molecular docking. Heliyon 2024; 10:e23183. [PMID: 38163140 PMCID: PMC10755284 DOI: 10.1016/j.heliyon.2023.e23183] [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: 11/18/2023] [Accepted: 11/28/2023] [Indexed: 01/03/2024] Open
Abstract
Aim and objective Due to the a lot of unexplored proteins in HIV-1, this research aimed to explore the functional roles of a hypothetical protein (AAB33144.1) that might play a key role in HIV-1 pathogenicity. Methods The homologous protein was identified along with building and validating the 3D structure by searching several bioinformatics tools. Results Retroviral aspartyl protease and retropepsin like functional domains and motifs, folding pattern (cupredoxins), and subcellular localization in cytoplasmic membrane were determined as biological activity. Besides, the functional annotation revealed that the chosen hypothetical protein possessed protease-like activity. To validate our generated protein 3D structure, molecular docking was performed with five compounds where nelfinavir showed (-8.2 kcal/mol) best binding affinity against HXB2 viral protease (PDB ID: 7SJX) and main protease (PDB ID: 4EYR) protein. Conclusions This study suggests that the annotated hypothetical protein related to protease action, which may be useful in viral genetics and drug discovery.
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Affiliation(s)
- Md. Imran Hossain
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
| | - Anika Tabassum Asha
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
| | - Md. Arju Hossain
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
| | - Shahin Mahmud
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
| | - Kamal Chowdhury
- Biology Department, Claflin University, 400 Magnolia St, Orangeburg, SC 29115, USA
| | - Ramisa Binti Mohiuddin
- Department of Pharmacy, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
| | - Nazneen Nahar
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
| | - Saborni Sarker
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
| | - Suhaimi Napis
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor D.E., Malaysia
| | - Md Sanower Hossain
- Centre for Sustainability of Mineral and Resource Recovery Technology (Pusat SMaRRT), Universiti Malaysia Pahang Al-Sultan Abdullah, Kuantan 26300, Malaysia
| | - A.K.M. Mohiuddin
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh
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6
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Cabrera-Rodríguez R, Pérez-Yanes S, Lorenzo-Sánchez I, Trujillo-González R, Estévez-Herrera J, García-Luis J, Valenzuela-Fernández A. HIV Infection: Shaping the Complex, Dynamic, and Interconnected Network of the Cytoskeleton. Int J Mol Sci 2023; 24:13104. [PMID: 37685911 PMCID: PMC10487602 DOI: 10.3390/ijms241713104] [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: 08/08/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
HIV-1 has evolved a plethora of strategies to overcome the cytoskeletal barrier (i.e., actin and intermediate filaments (AFs and IFs) and microtubules (MTs)) to achieve the viral cycle. HIV-1 modifies cytoskeletal organization and dynamics by acting on associated adaptors and molecular motors to productively fuse, enter, and infect cells and then traffic to the cell surface, where virions assemble and are released to spread infection. The HIV-1 envelope (Env) initiates the cycle by binding to and signaling through its main cell surface receptors (CD4/CCR5/CXCR4) to shape the cytoskeleton for fusion pore formation, which permits viral core entry. Then, the HIV-1 capsid is transported to the nucleus associated with cytoskeleton tracks under the control of specific adaptors/molecular motors, as well as HIV-1 accessory proteins. Furthermore, HIV-1 drives the late stages of the viral cycle by regulating cytoskeleton dynamics to assure viral Pr55Gag expression and transport to the cell surface, where it assembles and buds to mature infectious virions. In this review, we therefore analyze how HIV-1 generates a cell-permissive state to infection by regulating the cytoskeleton and associated factors. Likewise, we discuss the relevance of this knowledge to understand HIV-1 infection and pathogenesis in patients and to develop therapeutic strategies to battle HIV-1.
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Affiliation(s)
- Romina Cabrera-Rodríguez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Silvia Pérez-Yanes
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Iria Lorenzo-Sánchez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Rodrigo Trujillo-González
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
- Analysis Department, Faculty of Mathematics, Universidad de La Laguna (ULL), 38200 La Laguna, Spain
| | - Judith Estévez-Herrera
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Jonay García-Luis
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
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7
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Abstract
The biggest challenge to immune control of HIV infection is the rapid within-host viral evolution, which allows selection of viral variants that escape from T cell and antibody recognition. Thus, it is impossible to clear HIV infection without targeting "immutable" components of the virus. Unlike the adaptive immune system that recognizes cognate epitopes, the CARD8 inflammasome senses the essential enzymatic activity of the HIV-1 protease, which is immutable for the virus. Hence, all subtypes of HIV clinical isolates can be recognized by CARD8. In HIV-infected cells, the viral protease is expressed as a subunit of the viral Gag-Pol polyprotein and remains functionally inactive prior to viral budding. A class of anti-HIV drugs, the non-nucleoside reverse transcriptase inhibitors (NNRTIs), can promote Gag-pol dimerization and subsequent premature intracellular activation of the viral protease. NNRTI treatment triggers CARD8 inflammasome activation, which leads to pyroptosis of HIV-infected CD4+ T cells and macrophages. Targeting the CARD8 inflammasome can be a potent and broadly effective strategy for HIV eradication.
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Affiliation(s)
- Kolin M Clark
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States
| | - Priya Pal
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States
| | - Josh G Kim
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States
| | - Qiankun Wang
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States
| | - Liang Shan
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, Saint Louis, MO, United States; Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, Saint Louis, MO, United States.
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8
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Harrison JJEK, Passos DO, Bruhn JF, Bauman JD, Tuberty L, DeStefano JJ, Ruiz FX, Lyumkis D, Arnold E. Cryo-EM structure of the HIV-1 Pol polyprotein provides insights into virion maturation. SCIENCE ADVANCES 2022; 8:eabn9874. [PMID: 35857464 PMCID: PMC9258950 DOI: 10.1126/sciadv.abn9874] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
Key proteins of retroviruses and other RNA viruses are translated and subsequently processed from polyprotein precursors by the viral protease (PR). Processing of the HIV Gag-Pol polyprotein yields the HIV structural proteins and enzymes. Structures of the mature enzymes PR, reverse transcriptase (RT), and integrase (IN) aided understanding of catalysis and design of antiretrovirals, but knowledge of the Pol precursor architecture and function before PR cleavage is limited. We developed a system to produce stable HIV-1 Pol and determined its cryo-electron microscopy structure. RT in Pol has a similar arrangement to the mature RT heterodimer, and its dimerization may draw together two PR monomers to activate proteolytic processing. HIV-1 thus may leverage the dimerization interfaces in Pol to regulate assembly and maturation of polyprotein precursors.
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Affiliation(s)
- Jerry Joe E. K. Harrison
- Center for Advanced Biotechnology and Medicine (CABM), Piscataway, NJ, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, USA
- Department of Chemistry, University of Ghana, Legon, Ghana
| | | | - Jessica F. Bruhn
- The Salk Institute for Biological Studies, La Jolla, CA, USA
- NanoImaging Services, San Diego, CA, USA
| | - Joseph D. Bauman
- Center for Advanced Biotechnology and Medicine (CABM), Piscataway, NJ, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, USA
| | - Lynda Tuberty
- Center for Advanced Biotechnology and Medicine (CABM), Piscataway, NJ, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, USA
| | - Jeffrey J. DeStefano
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD, USA
| | - Francesc Xavier Ruiz
- Center for Advanced Biotechnology and Medicine (CABM), Piscataway, NJ, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, USA
| | - Dmitry Lyumkis
- The Salk Institute for Biological Studies, La Jolla, CA, USA
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Eddy Arnold
- Center for Advanced Biotechnology and Medicine (CABM), Piscataway, NJ, USA
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ, USA
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9
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Pak A, Gupta M, Yeager M, Voth GA. Inositol Hexakisphosphate (IP6) Accelerates Immature HIV-1 Gag Protein Assembly toward Kinetically Trapped Morphologies. J Am Chem Soc 2022; 144:10417-10428. [PMID: 35666943 PMCID: PMC9204763 DOI: 10.1021/jacs.2c02568] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
During the late stages of the HIV-1 lifecycle, immature virions are produced by the concerted activity of Gag polyproteins, primarily mediated by the capsid (CA) and spacer peptide 1 (SP1) domains, which assemble into a spherical lattice, package viral genomic RNA, and deform the plasma membrane. Recently, inositol hexakisphosphate (IP6) has been identified as an essential assembly cofactor that efficiently produces both immature virions in vivo and immature virus-like particles in vitro. To date, however, several distinct mechanistic roles for IP6 have been proposed on the basis of independent functional, structural, and kinetic studies. In this work, we investigate the molecular influence of IP6 on the structural outcomes and dynamics of CA/SP1 assembly using coarse-grained (CG) molecular dynamics (MD) simulations and free energy calculations. Here, we derive a bottom-up, low-resolution, and implicit-solvent CG model of CA/SP1 and IP6, and simulate their assembly under conditions that emulate both in vitro and in vivo systems. Our analysis identifies IP6 as an assembly accelerant that promotes curvature generation and fissure-like defects throughout the lattice. Our findings suggest that IP6 induces kinetically trapped immature morphologies, which may be physiologically important for later stages of viral morphogenesis and potentially useful for virus-like particle technologies.
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Affiliation(s)
- Alexander
J. Pak
- Department
of Chemistry, Chicago Center for Theoretical Chemistry, Institute
for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Manish Gupta
- Department
of Chemistry, Chicago Center for Theoretical Chemistry, Institute
for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Mark Yeager
- Department
of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22908, United States,Center
for Membrane Biology, University of Virginia
School of Medicine, Charlottesville, Virginia 22908, United States, United States,Cardiovascular
Research Center, University of Virginia
School of Medicine, Charlottesville, Virginia 22908, United States,Department
of Medicine, Division of Cardiovascular Medicine, University of Virginia School of Medicine, Charlottesville, Virginia 22908, United States
| | - Gregory A. Voth
- Department
of Chemistry, Chicago Center for Theoretical Chemistry, Institute
for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States,E-mail:
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10
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Natural Immunity against HIV-1: Progression of Understanding after Association Studies. Viruses 2022; 14:v14061243. [PMID: 35746714 PMCID: PMC9227919 DOI: 10.3390/v14061243] [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: 05/16/2022] [Revised: 06/01/2022] [Accepted: 06/03/2022] [Indexed: 11/17/2022] Open
Abstract
Natural immunity against HIV has been observed in many individuals in the world. Among them, a group of female sex workers enrolled in the Pumwani sex worker cohort remained HIV uninfected for more than 30 years despite high-risk sex work. Many studies have been carried out to understand this natural immunity to HIV in the hope to develop effective vaccines and preventions. This review focuses on two such examples. These studies started from identifying immunogenetic or genetic associations with resistance to HIV acquisition, and followed up with an in-depth investigation to understand the biological relevance of the correlations of protection, and to develop and test novel vaccines and preventions.
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11
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Climaco-Arvizu S, Flores-López V, González-Torres C, Gaytán-Cervantes FJ, Hernández-García MC, Zárate-Segura PB, Chávez-Torres M, Tesoro-Cruz E, Pinto-Cardoso SM, Bekker-Méndez VC. Protease and gag diversity and drug resistance mutations among treatment-naive Mexican people living with HIV. BMC Infect Dis 2022; 22:447. [PMID: 35538426 PMCID: PMC9088029 DOI: 10.1186/s12879-022-07446-8] [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: 03/03/2022] [Accepted: 04/29/2022] [Indexed: 08/30/2023] Open
Abstract
Introduction In Mexico, HIV genotyping is performed in people living with HIV (PLWH) failing their first-line antiretroviral (ARV) regimen; it is not routinely done for all treatment-naive PLWH before ARV initiation. The first nationally representative survey published in 2016 reported that the prevalence of pretreatment drug mutations in treatment-naive Mexican PLWH was 15.5% to any antiretroviral drug and 10.6% to non-nucleoside reverse transcriptase inhibitors (NNRTIs) using conventional Sanger sequencing. Most reports in Mexico focus on HIV pol gene and nucleoside and non-nucleoside reverse transcriptase inhibitor (NRTI and NNRTI) drug resistance mutations (DRMs) prevalence, using Sanger sequencing, next-generation sequencing (NGS) or both. To our knowledge, NGS has not be used to detect pretreatment drug resistance mutations (DRMs) in the HIV protease (PR) gene and its substrate the Gag polyprotein. Methods Treatment-naive adult Mexican PLWH were recruited between 2016 and 2019. HIV Gag and protease sequences were obtained by NGS and DRMs were identified using the WHO surveillance drug resistance mutation (SDRM) list. Results One hundred PLWH attending a public national reference hospital were included. The median age was 28 years-old, and most were male. The median HIV viral load was 4.99 [4.39–5.40] log copies/mL and median CD4 cell count was 150 [68.0–355.78] cells/mm3. As expected, most sequences clustered with HIV-1 subtype B (97.9%). Major PI resistance mutations were detected: 8 (8.3%) of 96 patients at a detection threshold of 1% and 3 (3.1%) at a detection threshold of 20%. A total of 1184 mutations in Gag were detected, of which 51 have been associated with resistance to PI, most of them were detected at a threshold of 20%. Follow-up clinical data was available for 79 PLWH at 6 months post-ART initiation, seven PLWH failed their first ART regimen; however no major PI mutations were identified in these individuals at baseline. Conclusions The frequency of DRM in the HIV protease was 7.3% at a detection threshold of 1% and 3.1% at a detection threshold of 20%. NGS-based HIV drug resistance genotyping provide improved detection of DRMs. Viral load was used to monitor ARV response and treatment failure was 8.9%. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-022-07446-8.
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Affiliation(s)
- Samantha Climaco-Arvizu
- Unidad de Investigación Médica en Inmunología e Infectología, Hospital de Infectología "Dr Daniel Méndez Hernández", Centro Médico Nacional "La Raza", Instituto Mexicano del Seguro Social (IMSS), Ciudad de México, C.P. 02990, México.,Laboratorio de Medicina Traslacional, Instituto Politécnico Nacional, Ciudad de México, México
| | | | - Carolina González-Torres
- División de Desarrollo de La Investigación, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | | | - María Concepción Hernández-García
- Instituto Mexicano del Seguro Social (IMSS), Hospital de Infectología "Dr Daniel Méndez Hernández", Centro Médico Nacional (CMN), La Raza", Ciudad de México, México
| | | | - Monserrat Chávez-Torres
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, C.P. 14080, México
| | - Emiliano Tesoro-Cruz
- Unidad de Investigación Médica en Inmunología e Infectología, Hospital de Infectología "Dr Daniel Méndez Hernández", Centro Médico Nacional "La Raza", Instituto Mexicano del Seguro Social (IMSS), Ciudad de México, C.P. 02990, México
| | - Sandra María Pinto-Cardoso
- Centro de Investigación en Enfermedades Infecciosas, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Ciudad de México, C.P. 14080, México.
| | - Vilma Carolina Bekker-Méndez
- Unidad de Investigación Médica en Inmunología e Infectología, Hospital de Infectología "Dr Daniel Méndez Hernández", Centro Médico Nacional "La Raza", Instituto Mexicano del Seguro Social (IMSS), Ciudad de México, C.P. 02990, México.
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12
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The HIV-1 Viral Protease Is Activated during Assembly and Budding Prior to Particle Release. J Virol 2022; 96:e0219821. [PMID: 35438536 DOI: 10.1128/jvi.02198-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 encodes a viral protease that is essential for the maturation of infectious viral particles. While protease inhibitors are effective antiretroviral agents, recent studies have shown that prematurely activating, rather than inhibiting, protease function leads to the pyroptotic death of infected cells, with exciting implications for efforts to eradicate viral reservoirs. Despite 40 years of research into the kinetics of protease activation, it remains unclear exactly when protease becomes activated. Recent reports have estimated that protease activation occurs minutes to hours after viral release, suggesting that premature protease activation is challenging to induce efficiently. Here, monitoring viral protease activity with sensitive techniques, including nanoscale flow cytometry and instant structured illumination microscopy, we demonstrate that the viral protease is activated within cells prior to the release of free virions. Using genetic mutants that lock protease into a precursor conformation, we further show that both the precursor and mature protease have rapid activation kinetics and that the activity of the precursor protease is sufficient for viral fusion with target cells. Our finding that HIV-1 protease is activated within producer cells prior to release of free virions helps resolve a long-standing question of when protease is activated and suggests that only a modest acceleration of protease activation kinetics is required to induce potent and specific elimination of HIV-infected cells. IMPORTANCE HIV-1 protease inhibitors have been a mainstay of antiretroviral therapy for more than 2 decades. Although antiretroviral therapy is effective at controlling HIV-1 replication, persistent reservoirs of latently infected cells quickly reestablish replication if therapy is halted. A promising new strategy to eradicate the latent reservoir involves prematurely activating the viral protease, which leads to the pyroptotic killing of infected cells. Here, we use highly sensitive techniques to examine the kinetics of protease activation during and shortly after particle formation. We found that protease is fully activated before virus is released from the cell membrane, which is hours earlier than recent estimates. Our findings help resolve a long-standing debate as to when the viral protease is initially activated during viral assembly and confirm that prematurely activating HIV-1 protease is a viable strategy to eradicate infected cells following latency reversal.
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13
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Lin YR, Chu SM, Yu FH, Huang KJ, Wang CT. Effects of reduced gag cleavage efficiency on HIV-1 Gag-Pol package. BMC Microbiol 2022; 22:94. [PMID: 35395730 PMCID: PMC8994222 DOI: 10.1186/s12866-022-02503-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 03/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND HIV-1 pol, which encodes enzymes required for virus replication, is initially translated as a Gag-Pol fusion protein. Gag-Pol is incorporated into virions via interactions with Gag precursor Pr55gag. Protease (PR) embedded in Gag-Pol mediates the proteolytic processing of both Pr55gag and Gag-Pol during or soon after virus particle release from cells. Since efficient Gag-Pol viral incorporation depends on interaction with Pr55gag via its N-terminal Gag domain, the prevention of premature Gag cleavage may alleviate Gag-Pol packaging deficiencies associated with cleavage enhancement from PR. RESULTS We engineered PR cleavage-blocking Gag mutations with the potential to significantly reduce Gag processing efficiency. Such mutations may mitigate the negative effects of enhanced PR activation on virus assembly and Gag-Pol packaging due to an RT dimerization enhancer or leucine zipper dimerization motif. When co-expressed with Pr55gag, we noted that enhanced PR activation resulted in reduced Gag-Pol cis or trans incorporation into Pr55gag particles, regardless of whether or not Gag cleavage sites within Gag-Pol were blocked. CONCLUSIONS Our data suggest that the amount of HIV-1 Gag-Pol or Pol viral incorporation is largely dependent on virus particle production, and that cleavage blocking in the Gag-Pol N-terminal Gag domain does not exert significant impacts on Pol packaging.
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Affiliation(s)
- Yi-Ru Lin
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University School of Medicine, 112, Taipei, Taiwan
| | - Shih-Ming Chu
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University School of Medicine, 112, Taipei, Taiwan
| | - Fu-Hsien Yu
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University School of Medicine, 112, Taipei, Taiwan
| | - Kuo-Jung Huang
- Division of Clinical Research, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chin-Tien Wang
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University School of Medicine, 112, Taipei, Taiwan. .,Division of Clinical Research, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan.
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14
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Lerner G, Weaver N, Anokhin B, Spearman P. Advances in HIV-1 Assembly. Viruses 2022; 14:v14030478. [PMID: 35336885 PMCID: PMC8952333 DOI: 10.3390/v14030478] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 12/10/2022] Open
Abstract
The assembly of HIV-1 particles is a concerted and dynamic process that takes place on the plasma membrane of infected cells. An abundance of recent discoveries has advanced our understanding of the complex sequence of events leading to HIV-1 particle assembly, budding, and release. Structural studies have illuminated key features of assembly and maturation, including the dramatic structural transition that occurs between the immature Gag lattice and the formation of the mature viral capsid core. The critical role of inositol hexakisphosphate (IP6) in the assembly of both the immature and mature Gag lattice has been elucidated. The structural basis for selective packaging of genomic RNA into virions has been revealed. This review will provide an overview of the HIV-1 assembly process, with a focus on recent advances in the field, and will point out areas where questions remain that can benefit from future investigation.
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15
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Amino acid substitutions at the HIV-1 transframe region significantly impair virus infectivity. PLoS One 2022; 17:e0262477. [PMID: 35085286 PMCID: PMC8794111 DOI: 10.1371/journal.pone.0262477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 12/24/2021] [Indexed: 11/25/2022] Open
Abstract
A transframe region within HIV-1 Gag-Pol (referred to as p6* or p6pol), directly linked to the protease (PR) N-terminus, plays a pivotal role in modulating PR activation. To identify specific p6* residues involved in PR activation, we created a series of p6* mutants by making substitutions for conserved p6* residues. Our results indicate that some p6* mutants were defective in terms of virus infectivity, despite displaying a wild-type virus particle processing pattern. Mutations at p6* F8 reduced virus infectivity associated with insufficient virus processing, due in part to impaired PR maturation and RT packaging. Our data strongly suggest that conserved Phe (F) residues at position 8 of p6* are involved in the PR maturation process.
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16
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Co-evolution of drug resistance and broadened substrate recognition in HIV protease variants isolated from an Escherichia coli genetic selection system. Biochem J 2022; 479:479-501. [PMID: 35089310 DOI: 10.1042/bcj20210767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/07/2022] [Accepted: 01/28/2022] [Indexed: 11/17/2022]
Abstract
A genetic selection system for activity of HIV protease is described that is based on a synthetic substrate constructed as a modified AraC regulatory protein that when cleaved stimulate L-arabinose metabolism in an Escherichia coli araC strain. Growth stimulation on selective plates was shown to depend on active HIV protease and the scissile bond in the substrate. In addition, the growth of cells correlated well with the established cleavage efficiency of the sites in the viral polyprotein, Gag, when these sites were individually introduced into the synthetic substate of the selection system. Plasmids encoding protease variants selected based on stimulation of cell growth in the presence of saquinavir or cleavage of a site not cleaved by wild-type protease, were indistinguishable with respect to both phenotypes. Also, both groups of selected plasmids encoded side chain substitutions known from clinical isolates or displayed different side chain substitutions but at identical positions. One highly frequent side chain substitution, E34V, not regarded as a major drug resistance substitution was found in variants obtained under both selective conditions and is suggested to improve protease processing of the synthetic substrate. This substitution is away from the substrate-binding cavity and together with other substitutions in the selected reading frames supports the previous suggestion of a substrate-binding site extended from the active site binding pocket itself.
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17
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Ilina TV, Brosenitsch T, Sluis-Cremer N, Ishima R. Retroviral RNase H: Structure, mechanism, and inhibition. Enzymes 2021; 50:227-247. [PMID: 34861939 DOI: 10.1016/bs.enz.2021.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
All retroviruses encode the enzyme, reverse transcriptase (RT), which is involved in the conversion of the single-stranded viral RNA genome into double-stranded DNA. RT is a multifunctional enzyme and exhibits DNA polymerase and ribonuclease H (RNH) activities, both of which are essential to the reverse-transcription process. Despite the successful development of polymerase-targeting antiviral drugs over the last three decades, no bona fide inhibitor against the RNH activity of HIV-1 RT has progressed to clinical evaluation. In this review article, we describe the retroviral RNH function and inhibition, with primary consideration of the structural aspects of inhibition.
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Affiliation(s)
- Tatiana V Ilina
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Teresa Brosenitsch
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Nicolas Sluis-Cremer
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Rieko Ishima
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
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18
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Pak AJ, Purdy MD, Yeager M, Voth GA. Preservation of HIV-1 Gag Helical Bundle Symmetry by Bevirimat Is Central to Maturation Inhibition. J Am Chem Soc 2021; 143:19137-19148. [PMID: 34739240 DOI: 10.1021/jacs.1c08922] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The assembly and maturation of human immunodeficiency virus type 1 (HIV-1) require proteolytic cleavage of the Gag polyprotein. The rate-limiting step resides at the junction between the capsid protein CA and spacer peptide 1, which assembles as a six-helix bundle (6HB). Bevirimat (BVM), the first-in-class maturation inhibitor drug, targets the 6HB and impedes proteolytic cleavage, yet the molecular mechanisms of its activity, and relatedly, the escape mechanisms of mutant viruses, remain unclear. Here, we employed extensive molecular dynamics (MD) simulations and free energy calculations to quantitatively investigate molecular structure-activity relationships, comparing wild-type and mutant viruses in the presence and absence of BVM and inositol hexakisphosphate (IP6), an assembly cofactor. Our analysis shows that the efficacy of BVM is directly correlated with preservation of 6-fold symmetry in the 6HB, which exists as an ensemble of structural states. We identified two primary escape mechanisms, and both lead to loss of symmetry, thereby facilitating helix uncoiling to aid access of protease. Our findings also highlight specific interactions that can be targeted for improved inhibitor activity and support the use of MD simulations for future inhibitor design.
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Affiliation(s)
- Alexander J Pak
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - Michael D Purdy
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22908, United States
| | - Mark Yeager
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22908, United States.,Center for Membrane Biology, University of Virginia School of Medicine, Charlottesville, Virginia 22908, United States.,Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia 22908, United States.,Department of Medicine, Division of Cardiovascular Medicine, University of Virginia School of Medicine, Charlottesville, Virginia 22908, United States
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
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19
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Imamichi T, Bernbaum JG, Laverdure S, Yang J, Chen Q, Highbarger H, Hao M, Sui H, Dewar R, Chang W, Lane HC. Natural Occurring Polymorphisms in HIV-1 Integrase and RNase H Regulate Viral Release and Autoprocessing. J Virol 2021; 95:e0132321. [PMID: 34523971 PMCID: PMC8577372 DOI: 10.1128/jvi.01323-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 09/07/2021] [Indexed: 01/19/2023] Open
Abstract
Recently, a genome-wide association study using plasma HIV RNA from antiretroviral therapy-naive patients reported that 14 naturally occurring nonsynonymous single-nucleotide polymorphisms (SNPs) in HIV derived from antiretrovirus drug-naive patients were associated with virus load (VL). Those SNPs were detected in reverse transcriptase, RNase H, integrase, envelope, and Nef. However, the impact of each mutation on viral fitness was not investigated. Here, we constructed a series of HIV variants encoding each SNP and examined their replicative abilities. An HIV variant containing a Met-to-Ile change at codon 50 in integrase [HIV(IN:M50I)] was found as an impaired virus. Despite the mutation being in integrase, the virus release was significantly suppressed (P < 0.001). Transmission electron microscopy analysis revealed that abnormal bud accumulation on the plasma membrane and the released virus particles retained immature forms. Western blot analysis demonstrated a defect in autoprocessing of GagPol and Gag polyproteins' autoprocessing in the HIV(IN:M50I) particles, although Förster resonance energy transfer (FRET) assay displayed that GagPol containing IN:M50I forms a homodimer with a similar efficiency with GagPol (wild type). The impaired maturation and replication were rescued by two other VL-associated SNPs, Ser-to-Asn change at codon 17 of integrase and Asn-to-Ser change at codon 79 of RNase H. These data demonstrate that Gag and GagPol assembly, virus release, and autoprocessing are regulated by not only integrase but also RNase H. IMPORTANCE Nascent HIV-1 is a noninfectious viral particle. Cleaving Gag and GagPol polyproteins in the particle by mature HIV protease (PR), the nascent virus becomes an infectious virus. PR is initially translated as an inactive embedded enzyme in a GagPol polyprotein. The embedded PR in homodimerized GagPol polyproteins catalyzes a proteolytic reaction to release the mature PR. This excision step by self-cleavage is called autoprocessing. Here, during the evaluation of the roles of naturally emerging nonsynonymous SNPs in HIV RNA, we found that autoprocessing is inhibited by Met-to-Ile change at codon 50 in integrase GagPol. Other coexisting SNPs, Ser-to-Asn change at codon 17 in integrase or Asn-to-Ser mutation at codon 79 in RNase H, recovered this defect, suggesting that autoprocessing is regulated by not only integrase but also RNase H in GagPol polyprotein.
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Affiliation(s)
- Tomozumi Imamichi
- Laboratory of Human Retrovirology and Immunoinformatics, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - John G. Bernbaum
- Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, Maryland, USA
| | - Sylvain Laverdure
- Laboratory of Human Retrovirology and Immunoinformatics, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - Jun Yang
- Laboratory of Human Retrovirology and Immunoinformatics, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - Qian Chen
- Laboratory of Human Retrovirology and Immunoinformatics, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - Helene Highbarger
- Virus Isolation and Serology Laboratory, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - Ming Hao
- Laboratory of Human Retrovirology and Immunoinformatics, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - Hongyan Sui
- Laboratory of Human Retrovirology and Immunoinformatics, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - Robin Dewar
- Virus Isolation and Serology Laboratory, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - Weizhong Chang
- Laboratory of Human Retrovirology and Immunoinformatics, Applied and Developmental Directorate, Frederick National Laboratory, Frederick, Maryland, USA
| | - H. Clifford Lane
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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20
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Saha I, Preece B, Peterson A, Durden H, MacArthur B, Lowe J, Belnap D, Vershinin M, Saffarian S. Gag-Gag Interactions Are Insufficient to Fully Stabilize and Order the Immature HIV Gag Lattice. Viruses 2021; 13:1946. [PMID: 34696376 PMCID: PMC8540168 DOI: 10.3390/v13101946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022] Open
Abstract
Immature HIV virions harbor a lattice of Gag molecules with significant ordering in CA-NTD, CA-CTD and SP1 regions. This ordering plays a major role during HIV maturation. To test the condition in which the Gag lattice forms in vivo, we assembled virus like particles (VLPs) by expressing only HIV Gag in mammalian cells. Here we show that these VLPs incorporate a similar number of Gag molecules compared to immature HIV virions. However, within these VLPs, Gag molecules diffuse with a pseudo-diffusion rate of 10 nm2/s, this pseudo-diffusion is abrogated in the presence of melittin and is sensitive to mutations within the SP1 region. Using cryotomography, we show that unlike immature HIV virions, in the Gag lattice of VLPs the CA-CTD and SP1 regions are significantly less ordered. Our observations suggest that within immature HIV virions, other viral factors in addition to Gag, contribute to ordering in the CA-CTD and SP1 regions.
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Affiliation(s)
- Ipsita Saha
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA;
| | - Benjamin Preece
- Center for Cell and Genome Science, University of Utah, Salt Lake City, UT 84112, USA; (B.P.); (A.P.); (H.D.); (B.M.); (M.V.)
- Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA
| | - Abby Peterson
- Center for Cell and Genome Science, University of Utah, Salt Lake City, UT 84112, USA; (B.P.); (A.P.); (H.D.); (B.M.); (M.V.)
- Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA
| | - Haley Durden
- Center for Cell and Genome Science, University of Utah, Salt Lake City, UT 84112, USA; (B.P.); (A.P.); (H.D.); (B.M.); (M.V.)
- Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA
| | - Brian MacArthur
- Center for Cell and Genome Science, University of Utah, Salt Lake City, UT 84112, USA; (B.P.); (A.P.); (H.D.); (B.M.); (M.V.)
- Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA
| | - Jake Lowe
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA; (J.L.); (D.B.)
| | - David Belnap
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA; (J.L.); (D.B.)
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Michael Vershinin
- Center for Cell and Genome Science, University of Utah, Salt Lake City, UT 84112, USA; (B.P.); (A.P.); (H.D.); (B.M.); (M.V.)
- Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA; (J.L.); (D.B.)
| | - Saveez Saffarian
- Center for Cell and Genome Science, University of Utah, Salt Lake City, UT 84112, USA; (B.P.); (A.P.); (H.D.); (B.M.); (M.V.)
- Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA; (J.L.); (D.B.)
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21
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Jiang K, Humbert N, K K S, Rouzina I, Mely Y, Westerlund F. The HIV-1 nucleocapsid chaperone protein forms locally compacted globules on long double-stranded DNA. Nucleic Acids Res 2021; 49:4550-4563. [PMID: 33872352 PMCID: PMC8096146 DOI: 10.1093/nar/gkab236] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 03/09/2021] [Accepted: 03/22/2021] [Indexed: 01/14/2023] Open
Abstract
The nucleocapsid (NC) protein plays key roles in Human Immunodeficiency Virus 1 (HIV-1) replication, notably by condensing and protecting the viral RNA genome and by chaperoning its reverse transcription into double-stranded DNA (dsDNA). Recent findings suggest that integration of viral dsDNA into the host genome, and hence productive infection, is linked to a small subpopulation of viral complexes where reverse transcription was completed within the intact capsid. Therefore, the synthesized dsDNA has to be tightly compacted, most likely by NC, to prevent breaking of the capsid in these complexes. To investigate NC’s ability to compact viral dsDNA, we here characterize the compaction of single dsDNA molecules under unsaturated NC binding conditions using nanofluidic channels. Compaction is shown to result from accumulation of NC at one or few compaction sites, which leads to small dsDNA condensates. NC preferentially initiates compaction at flexible regions along the dsDNA, such as AT-rich regions and DNA ends. Upon further NC binding, these condensates develop into a globular state containing the whole dsDNA molecule. These findings support NC’s role in viral dsDNA compaction within the mature HIV-1 capsid and suggest a possible scenario for the gradual dsDNA decondensation upon capsid uncoating and NC loss.
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Affiliation(s)
- Kai Jiang
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
| | - Nicolas Humbert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch F 67401, France
| | - Sriram K K
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, The Ohio State University, Center for Retroviral Research, and Center for RNA Biology, Columbus, OH 43210, USA
| | - Yves Mely
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch F 67401, France
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
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22
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Immature HIV-1 assembles from Gag dimers leaving partial hexamers at lattice edges as potential substrates for proteolytic maturation. Proc Natl Acad Sci U S A 2021; 118:2020054118. [PMID: 33397805 PMCID: PMC7826355 DOI: 10.1073/pnas.2020054118] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
HIV-1 particle assembly is driven by the viral Gag protein, which oligomerizes into a hexameric array on the inner surface of the viral envelope, forming a truncated spherical lattice containing large and small gaps. Gag is then cut by the viral protease, disassembles, and rearranges to form the mature, infectious virus. Here, we present structures and molecular dynamics simulations of the edges of the immature Gag lattice. Our analysis shows that Gag dimers are the basic assembly unit of the HIV-1 particle, lattice edges are partial hexamers, and partial hexamers are prone to structural changes allowing protease to cut Gag. These findings provide insights into assembly of the immature virus, its structure, and how it disassembles during maturation. The CA (capsid) domain of immature HIV-1 Gag and the adjacent spacer peptide 1 (SP1) play a key role in viral assembly by forming a lattice of CA hexamers, which adapts to viral envelope curvature by incorporating small lattice defects and a large gap at the site of budding. This lattice is stabilized by intrahexameric and interhexameric CA-CA interactions, which are important in regulating viral assembly and maturation. We applied subtomogram averaging and classification to determine the oligomerization state of CA at lattice edges and found that CA forms partial hexamers. These structures reveal the network of interactions formed by CA-SP1 at the lattice edge. We also performed atomistic molecular dynamics simulations of CA-CA interactions stabilizing the immature lattice and partial CA-SP1 helical bundles. Free energy calculations reveal increased propensity for helix-to-coil transitions in partial hexamers compared to complete six-helix bundles. Taken together, these results suggest that the CA dimer is the basic unit of lattice assembly, partial hexamers exist at lattice edges, these are in a helix-coil dynamic equilibrium, and partial helical bundles are more likely to unfold, representing potential sites for HIV-1 maturation initiation.
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23
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Weber IT, Wang YF, Harrison RW. HIV Protease: Historical Perspective and Current Research. Viruses 2021; 13:v13050839. [PMID: 34066370 PMCID: PMC8148205 DOI: 10.3390/v13050839] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 12/15/2022] Open
Abstract
The retroviral protease of human immunodeficiency virus (HIV) is an excellent target for antiviral inhibitors for treating HIV/AIDS. Despite the efficacy of therapy, current efforts to control the disease are undermined by the growing threat posed by drug resistance. This review covers the historical background of studies on the structure and function of HIV protease, the subsequent development of antiviral inhibitors, and recent studies on drug-resistant protease variants. We highlight the important contributions of Dr. Stephen Oroszlan to fundamental knowledge about the function of the HIV protease and other retroviral proteases. These studies, along with those of his colleagues, laid the foundations for the design of clinical inhibitors of HIV protease. The drug-resistant protease variants also provide an excellent model for investigating the molecular mechanisms and evolution of resistance.
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Affiliation(s)
- Irene T. Weber
- Department of Biology, Georgia State University, Atlanta, GA 30302, USA;
- Correspondence:
| | - Yuan-Fang Wang
- Department of Biology, Georgia State University, Atlanta, GA 30302, USA;
| | - Robert W. Harrison
- Department of Computer Science, Georgia State University, Atlanta, GA 30302, USA;
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24
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Mendonça L, Sun D, Ning J, Liu J, Kotecha A, Olek M, Frosio T, Fu X, Himes BA, Kleinpeter AB, Freed EO, Zhou J, Aiken C, Zhang P. CryoET structures of immature HIV Gag reveal six-helix bundle. Commun Biol 2021; 4:481. [PMID: 33863979 PMCID: PMC8052356 DOI: 10.1038/s42003-021-01999-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/18/2021] [Indexed: 11/09/2022] Open
Abstract
Gag is the HIV structural precursor protein which is cleaved by viral protease to produce mature infectious viruses. Gag is a polyprotein composed of MA (matrix), CA (capsid), SP1, NC (nucleocapsid), SP2 and p6 domains. SP1, together with the last eight residues of CA, have been hypothesized to form a six-helix bundle responsible for the higher-order multimerization of Gag necessary for HIV particle assembly. However, the structure of the complete six-helix bundle has been elusive. Here, we determined the structures of both Gag in vitro assemblies and Gag viral-like particles (VLPs) to 4.2 Å and 4.5 Å resolutions using cryo-electron tomography and subtomogram averaging by emClarity. A single amino acid mutation (T8I) in SP1 stabilizes the six-helix bundle, allowing to discern the entire CA-SP1 helix connecting to the NC domain. These structures provide a blueprint for future development of small molecule inhibitors that can lock SP1 in a stable helical conformation, interfere with virus maturation, and thus block HIV-1 infection.
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Affiliation(s)
- Luiza Mendonça
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Dapeng Sun
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jiying Ning
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jiwei Liu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Abhay Kotecha
- Thermo Fisher Scientific, Eindhoven, The Netherlands
| | - Mateusz Olek
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
- Department of Chemistry, University of York, York, UK
| | - Thomas Frosio
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | - Xiaofeng Fu
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Benjamin A Himes
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Alex B Kleinpeter
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Eric O Freed
- Virus-Cell Interaction Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Jing Zhou
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Christopher Aiken
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- Electron Bio-Imaging Centre, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK.
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25
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Toccafondi E, Lener D, Negroni M. HIV-1 Capsid Core: A Bullet to the Heart of the Target Cell. Front Microbiol 2021; 12:652486. [PMID: 33868211 PMCID: PMC8046902 DOI: 10.3389/fmicb.2021.652486] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/15/2021] [Indexed: 12/21/2022] Open
Abstract
The first step of the intracellular phase of retroviral infection is the release of the viral capsid core in the cytoplasm. This structure contains the viral genetic material that will be reverse transcribed and integrated into the genome of infected cells. Up to recent times, the role of the capsid core was considered essentially to protect this genetic material during the earlier phases of this process. However, increasing evidence demonstrates that the permanence inside the cell of the capsid as an intact, or almost intact, structure is longer than thought. This suggests its involvement in more aspects of the infectious cycle than previously foreseen, particularly in the steps of viral genomic material translocation into the nucleus and in the phases preceding integration. During the trip across the infected cell, many host factors are brought to interact with the capsid, some possessing antiviral properties, others, serving as viral cofactors. All these interactions rely on the properties of the unique component of the capsid core, the capsid protein CA. Likely, the drawback of ensuring these multiple functions is the extreme genetic fragility that has been shown to characterize this protein. Here, we recapitulate the busy agenda of an HIV-1 capsid in the infectious process, in particular in the light of the most recent findings.
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Affiliation(s)
- Elenia Toccafondi
- CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Université de Strasbourg, Strasbourg, France
| | - Daniela Lener
- CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Université de Strasbourg, Strasbourg, France
| | - Matteo Negroni
- CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Université de Strasbourg, Strasbourg, France
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26
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Li H, Omange RW, Liang B, Toledo N, Hai Y, Liu LR, Schalk D, Crecente-Campo J, Dacoba TG, Lambe AB, Lim SY, Li L, Kashem MA, Wan Y, Correia-Pinto JF, Seaman MS, Liu XQ, Balshaw RF, Li Q, Schultz-Darken N, Alonso MJ, Plummer FA, Whitney JB, Luo M. Vaccine targeting SIVmac251 protease cleavage sites protects macaques against vaginal infection. J Clin Invest 2021; 130:6429-6442. [PMID: 32853182 DOI: 10.1172/jci138728] [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: 04/08/2020] [Accepted: 08/20/2020] [Indexed: 01/03/2023] Open
Abstract
After over 3 decades of research, an effective anti-HIV vaccine remains elusive. The recently halted HVTN702 clinical trial not only further stresses the challenge to develop an effective HIV vaccine but also emphasizes that unconventional and novel vaccine strategies are urgently needed. Here, we report that a vaccine focusing the immune response on the sequences surrounding the 12 viral protease cleavage sites (PCSs) provided greater than 80% protection to Mauritian cynomolgus macaques against repeated intravaginal SIVmac251 challenges. The PCS-specific T cell responses correlated with vaccine efficacy. The PCS vaccine did not induce immune activation or inflammation known to be associated with increased susceptibility to HIV infection. Machine learning analyses revealed that the immune microenvironment generated by the PCS vaccine was predictive of vaccine efficacy. Our study demonstrates, for the first time to our knowledge, that a vaccine which targets only viral maturation, but lacks full-length Env and Gag immunogens, can prevent intravaginal infection in a stringent macaque/SIV challenge model. Targeting HIV maturation thus offers a potentially novel approach to developing an effective HIV vaccine.
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Affiliation(s)
- Hongzhao Li
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Robert W Omange
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Binhua Liang
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Nikki Toledo
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Yan Hai
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Lewis R Liu
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Dane Schalk
- Scientific Protocol Implementation Unit, Wisconsin National Primate Research Center, Madison, Wisconsin, USA
| | - Jose Crecente-Campo
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Tamara G Dacoba
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | | | - So-Yon Lim
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Lin Li
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Mohammad Abul Kashem
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Yanmin Wan
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Jorge F Correia-Pinto
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Michael S Seaman
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Xiao Qing Liu
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Obstetrics, Gynecology and Reproductive Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Robert F Balshaw
- Centre for Healthcare Innovation, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Qingsheng Li
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Nancy Schultz-Darken
- Scientific Protocol Implementation Unit, Wisconsin National Primate Research Center, Madison, Wisconsin, USA
| | - Maria J Alonso
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Francis A Plummer
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada.,National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - James B Whitney
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.,Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts, USA
| | - Ma Luo
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada.,National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
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27
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Large Multidomain Protein NMR: HIV-1 Reverse Transcriptase Precursor in Solution. Int J Mol Sci 2020; 21:ijms21249545. [PMID: 33333923 PMCID: PMC7765405 DOI: 10.3390/ijms21249545] [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: 11/22/2020] [Revised: 12/10/2020] [Accepted: 12/12/2020] [Indexed: 11/17/2022] Open
Abstract
NMR studies of large proteins, over 100 kDa, in solution are technically challenging and, therefore, of considerable interest in the biophysics field. The challenge arises because the molecular tumbling of a protein in solution considerably slows as molecular mass increases, reducing the ability to detect resonances. In fact, the typical 1H-13C or 1H-15N correlation spectrum of a large protein, using a 13C- or 15N-uniformly labeled protein, shows severe line-broadening and signal overlap. Selective isotope labeling of methyl groups is a useful strategy to reduce these issues, however, the reduction in the number of signals that goes hand-in-hand with such a strategy is, in turn, disadvantageous for characterizing the overall features of the protein. When domain motion exists in large proteins, the domain motion differently affects backbone amide signals and methyl groups. Thus, the use of multiple NMR probes, such as 1H, 19F, 13C, and 15N, is ideal to gain overall structural or dynamical information for large proteins. We discuss the utility of observing different NMR nuclei when characterizing a large protein, namely, the 66 kDa multi-domain HIV-1 reverse transcriptase that forms a homodimer in solution. Importantly, we present a biophysical approach, complemented by biochemical assays, to understand not only the homodimer, p66/p66, but also the conformational changes that contribute to its maturation to a heterodimer, p66/p51, upon HIV-1 protease cleavage.
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28
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Ilina T, Slack RL, Guerrero M, Ishima R. Effect of Lysyl-tRNA Synthetase on the Maturation of HIV-1 Reverse Transcriptase. ACS OMEGA 2020; 5:16619-16627. [PMID: 32685828 PMCID: PMC7364630 DOI: 10.1021/acsomega.0c01449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
In human immunodeficiency virus-1 (HIV-1), reverse transcriptase (RT) is encoded as a 66 kDa protein, p66, in the Gag-Pol polyprotein. This protein is proteolytically cleaved by HIV-1 protease (PR) to finally generate a mature RT that is a heterodimer, composed of a p66 subunit and a p66-derived 51 kDa subunit, p51. In our prior work, we demonstrated that tRNALys3 binding to p66/p66 facilitates efficient cleavage of p66 to p51 by PR. However, tRNALys3 is known to be recruited to the virus by forming a complex with lysyl-tRNA synthetase (LysRS). Herein, we tested whether LysRS can have an effect on RT maturation in vitro. Importantly, our data show no significant differences in RT maturation in the presence of LysRS. Furthermore, no apparent p66/66 interaction with LysRS was observed. Although PR cleaved LysRS, it did not immediately release tRNALys3 from LysRS. Thus, we conclude that a free fraction of tRNALys3, which is in equilibrium with a LysRS-bound form, interacts with p66/p66 without any additional mechanism involving release of tRNALys3 from LysRS. Given that only transient tRNALys3-p66/p66 interaction is needed for efficient RT maturation, a small amount of free tRNA may be sufficient for this process. These studies reveal molecular level insights into RT maturation and will be useful for the design of cellular/viral experiments to better understand the role of tRNA in HIV-1 replication.
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29
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Hakata Y, Li J, Fujino T, Tanaka Y, Shimizu R, Miyazawa M. Mouse APOBEC3 interferes with autocatalytic cleavage of murine leukemia virus Pr180gag-pol precursor and inhibits Pr65gag processing. PLoS Pathog 2019; 15:e1008173. [PMID: 31830125 PMCID: PMC6907756 DOI: 10.1371/journal.ppat.1008173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/30/2019] [Indexed: 01/01/2023] Open
Abstract
Mouse APOBEC3 (mA3) inhibits murine leukemia virus (MuLV) replication by a deamination-independent mechanism in which the reverse transcription is considered the main target process. However, other steps in virus replication that can be targeted by mA3 have not been examined. We have investigated the possible effect of mA3 on MuLV protease-mediated processes and found that mA3 binds both mature viral protease and Pr180gag-pol precursor polyprotein. Using replication-competent MuLVs, we also show that mA3 inhibits the processing of Pr65 Gag precursor. Furthermore, we demonstrate that the autoprocessing of Pr180gag-pol is impeded by mA3, resulting in reduced production of mature viral protease. This reduction appears to link with the above inefficient Pr65gag processing in the presence of mA3. Two major isoforms of mA3, exon 5-containing and -lacking ones, equally exhibit this antiviral activity. Importantly, physiologically expressed levels of mA3 impedes both Pr180gag-pol autocatalysis and Pr65gag processing. This blockade is independent of the deaminase activity and requires the C-terminal region of mA3. These results suggest that the above impairment of Pr180gag-pol autoprocessing may significantly contribute to the deaminase-independent antiretroviral activity exerted by mA3. Soon after the identification of the polynucleotide cytidine deaminase APOBEC3 as a host restriction factor against vif-deficient HIV, it was noticed that deamination-independent mechanisms are involved in the inhibition of viral replication in addition to the deaminase-dependent mechanism. We previously showed that mouse APOBEC3 (mA3) physiologically restricted mouse retrovirus replication in their natural hosts without causing significant G-to-A hypermutations. Inhibition of reverse transcription is reported to be the most plausible mechanism for the deamination-independent antiretroviral function. However, it remains unknown whether the inhibition of reverse transcription is the only way to explain the whole picture of deamination-independent antiviral activity exerted by APOBEC3. Here we show that mA3 targets the autoprocessing of Pr180gag-pol polyprotein. This activity does not require the deaminase catalytic center and mainly exerted by the C-terminal half of mA3. mA3 physically interacts with murine retroviral protease and its precursor Pr180gag-pol. mA3-induced disruption of the autocatalytic Pr180gag-pol cleavage leads to a significant reduction of mature viral protease, resulting in the inhibition of Pr65gag processing to mature Gag proteins. As the Pr180gag-pol autoprocessing is necessary for the maturation of other viral enzymes including the reverse transcriptase, its inhibition by host APOBEC3 may precede the previously described impairment of reverse transcription. Our discovery may lead to the development of novel antiretroviral drugs through the future identification of detailed molecular interfaces between retroviral Gag-Pol polyprotein and APOBEC3.
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Affiliation(s)
- Yoshiyuki Hakata
- Department of Immunology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
- * E-mail: (YH); (MM)
| | - Jun Li
- Department of Immunology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
- Ijunkai Medical Oncology, Endoscopy Clinic, Sakai-ku, Sakai, Osaka, Japan
| | - Takahiro Fujino
- Division of Analytical Bio-Medicine, Advanced Research Support Center (ADRES), Ehime University, Shitsukawa, Toon, Ehime, Japan
| | - Yuki Tanaka
- Division of Analytical Bio-Medicine, Advanced Research Support Center (ADRES), Ehime University, Shitsukawa, Toon, Ehime, Japan
| | - Rie Shimizu
- Department of Immunology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
| | - Masaaki Miyazawa
- Department of Immunology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
- Kindai University Anti-Aging Center, Higashiosaka, Osaka, Japan
- * E-mail: (YH); (MM)
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30
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Su CTT, Koh DWS, Gan SKE. Reviewing HIV-1 Gag Mutations in Protease Inhibitors Resistance: Insights for Possible Novel Gag Inhibitor Designs. Molecules 2019; 24:molecules24183243. [PMID: 31489889 PMCID: PMC6767625 DOI: 10.3390/molecules24183243] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 12/31/2022] Open
Abstract
HIV protease inhibitors against the viral protease are often hampered by drug resistance mutations in protease and in the viral substrate Gag. To overcome this drug resistance and inhibit viral maturation, targeting Gag alongside protease rather than targeting protease alone may be more efficient. In order to successfully inhibit Gag, understanding of its drug resistance mutations and the elicited structural changes on protease binding needs to be investigated. While mutations on Gag have already been mapped to protease inhibitor resistance, there remain many mutations, particularly the non-cleavage mutations, that are not characterized. Through structural studies to unravel how Gag mutations contributes to protease drug resistance synergistically, it is thus possible to glean insights to design novel Gag inhibitors. In this review, we discuss the structural role of both novel and previously reported Gag mutations in PI resistance, and how new Gag inhibitors can be designed.
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Affiliation(s)
- Chinh Tran-To Su
- Antibody & Product Development Lab, Bioinformatics Institute, A*STAR, Singapore 138671, Singapore
| | - Darius Wen-Shuo Koh
- Antibody & Product Development Lab, Bioinformatics Institute, A*STAR, Singapore 138671, Singapore
| | - Samuel Ken-En Gan
- Antibody & Product Development Lab, Bioinformatics Institute, A*STAR, Singapore 138671, Singapore.
- p53 Laboratory, A*STAR, Singapore 138648, Singapore.
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31
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Slack RL, Ilina TV, Xi Z, Giacobbi NS, Kawai G, Parniak MA, Sarafianos SG, Sluis Cremer N, Ishima R. Conformational Changes in HIV-1 Reverse Transcriptase that Facilitate Its Maturation. Structure 2019; 27:1581-1593.e3. [PMID: 31471129 DOI: 10.1016/j.str.2019.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 07/10/2019] [Accepted: 08/09/2019] [Indexed: 01/18/2023]
Abstract
HIV-1 reverse transcriptase (RT) is translated as part of the Gag-Pol polyprotein that is proteolytically processed by HIV-1 protease (PR) to finally become a mature heterodimer, composed of a p66 and a p66-derived 51-kDa subunit, p51. Our previous work suggested that tRNALys3 binding to p66/p66 introduces conformational changes in the ribonuclease (RNH) domain of RT that facilitate efficient cleavage of p66 to p51 by PR. In this study, we characterized the conformational changes in the RNH domain of p66/p66 imparted by tRNALys3 using NMR. Moreover, the importance of tRNALys3 in RT maturation was confirmed in cellulo by modulating the levels of Lys-tRNA synthetase, which affects recruitment of tRNALys3 to the virus. We also employed nonnucleoside RT inhibitors, to modulate the p66 dimer-monomer equilibrium and monitor the resulting structural changes. Taken together, our data provide unique insights into the conformational changes in p66/p66 that drive PR cleavage.
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Affiliation(s)
- Ryan L Slack
- Department of Structural Biology, University of Pittsburgh School of Medicine, Room 1037, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Tatiana V Ilina
- Department of Structural Biology, University of Pittsburgh School of Medicine, Room 1037, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Zhaoyong Xi
- Department of Structural Biology, University of Pittsburgh School of Medicine, Room 1037, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Nicholas S Giacobbi
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Gota Kawai
- Department of Life and Environmental Sciences, Chiba Institute of Technology, Chiba, Japan
| | - Michael A Parniak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Stefan G Sarafianos
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Nicolas Sluis Cremer
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
| | - Rieko Ishima
- Department of Structural Biology, University of Pittsburgh School of Medicine, Room 1037, Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA.
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32
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Huang L, Li L, Tien C, LaBarbera DV, Chen C. Targeting HIV-1 Protease Autoprocessing for High-throughput Drug Discovery and Drug Resistance Assessment. Sci Rep 2019; 9:301. [PMID: 30670786 PMCID: PMC6343032 DOI: 10.1038/s41598-018-36730-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/23/2018] [Indexed: 01/28/2023] Open
Abstract
HIV-1 protease autoprocessing liberates the free mature protease from its Gag-Pol polyprotein precursor through a series of highly regulated autoproteolysis reactions. Herein, we report the development and validation (Z' ≥ 0.50) of a cell-based functional assay for high-throughput screening (HTS) of autoprocessing inhibitors using fusion precursors in combination with AlphaLISA (amplified luminescent proximity homogeneous assay ELISA). Through pilot screening of a collection of 130 known protease inhibitors, the AlphaLISA assay confirmed all 11 HIV protease inhibitors in the library capable of suppressing precursor autoprocessing at low micromolar concentrations. Meanwhile, other protease inhibitors had no impact on precursor autoprocessing. We next conducted HTS of ~23,000 compounds but found no positive hits. Such high selectivity is advantageous for large-scale HTS campaigns and as anticipated based on assay design because a positive hit needs simultaneously to be nontoxic, cell permeable, and inhibiting precursor autoprocessing. Furthermore, AlphaLISA quantification of fusion precursors carrying mutations known to cause resistance to HIV protease inhibitors faithfully recapitulated the reported resistance, suggesting that precursor autoprocessing is a critical step contributing to drug resistance. Taken together, this reported AlphaLISA platform will provide a useful tool for drug discovery targeting HIV-1 protease autoprocessing and for quantification of PI resistance.
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Affiliation(s)
- Liangqun Huang
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Linfeng Li
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - ChihFeng Tien
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Daniel V LaBarbera
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Chaoping Chen
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA.
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33
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Potempa M, Lee SK, Kurt Yilmaz N, Nalivaika EA, Rogers A, Spielvogel E, Carter CW, Schiffer CA, Swanstrom R. HIV-1 Protease Uses Bi-Specific S2/S2' Subsites to Optimize Cleavage of Two Classes of Target Sites. J Mol Biol 2018; 430:5182-5195. [PMID: 30414407 DOI: 10.1016/j.jmb.2018.10.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/31/2018] [Accepted: 10/31/2018] [Indexed: 11/16/2022]
Abstract
Retroviral proteases (PRs) have a unique specificity that allows cleavage of sites with or without a P1' proline. A P1' proline is required at the MA/CA cleavage site due to its role in a post-cleavage conformational change in the capsid protein. However, the HIV-1 PR prefers to have large hydrophobic amino acids flanking the scissile bond, suggesting that PR recognizes two different classes of substrate sequences. We analyzed the cleavage rate of over 150 combinations of six different HIV-1 cleavage sites to explore rate determinants of cleavage. We found that cleavage rates are strongly influenced by the two amino acids flanking the amino acids at the scissile bond (P2-P1/P1'-P2'), with two complementary sets of rules. When P1' is proline, the P2 side chain interacts with a polar region in the S2 subsite of the PR, while the P2' amino acid interacts with a hydrophobic region of the S2' subsite. When P1' is not proline, the orientations of the P2 and P2' side chains with respect to the scissile bond are reversed; P2 residues interact with a hydrophobic face of the S2 subsite, while the P2' amino acid usually engages hydrophilic amino acids in the S2' subsite. These results reveal that the HIV-1 PR has evolved bi-functional S2 and S2' subsites to accommodate the steric effects imposed by a P1' proline on the orientation of P2 and P2' substrate side chains. These results also suggest a new strategy for inhibitor design to engage the multiple specificities in these subsites.
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Affiliation(s)
- Marc Potempa
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Sook-Kyung Lee
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ellen A Nalivaika
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Amy Rogers
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ean Spielvogel
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Charles W Carter
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ronald Swanstrom
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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High-resolution structures of HIV-1 Gag cleavage mutants determine structural switch for virus maturation. Proc Natl Acad Sci U S A 2018; 115:E9401-E9410. [PMID: 30217893 PMCID: PMC6176557 DOI: 10.1073/pnas.1811237115] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The main structural component of HIV-1 is the Gag polyprotein. During virus release, Gag is cleaved by the viral protease at five sites, triggering a major change in the structure and morphology of the virus. This transition, called maturation, is required to make an infectious virion. We used cryoelectron tomography to obtain high-resolution structures of Gag inside virus particles carrying mutations that block specific combinations of cleavage sites. Analysis of these structures suggests that different combinations of cleavages can destabilize a bundle of alpha-helices at the C terminus of CA. This destabilization, rather than formation of a beta-hairpin at the N terminus of CA as previously suggested, acts as the structural switch for maturation of the virus into its infectious form. HIV-1 maturation occurs via multiple proteolytic cleavages of the Gag polyprotein, causing rearrangement of the virus particle required for infectivity. Cleavage results in beta-hairpin formation at the N terminus of the CA (capsid) protein and loss of a six-helix bundle formed by the C terminus of CA and the neighboring SP1 peptide. How individual cleavages contribute to changes in protein structure and interactions, and how the mature, conical capsid forms, are poorly understood. Here, we employed cryoelectron tomography to determine morphology and high-resolution CA lattice structures for HIV-1 derivatives in which Gag cleavage sites are mutated. These analyses prompt us to revise current models for the crucial maturation switch. Unlike previously proposed, cleavage on either terminus of CA was sufficient, in principle, for lattice maturation, while complete processing was needed for conical capsid formation. We conclude that destabilization of the six-helix bundle, rather than beta-hairpin formation, represents the main determinant of structural maturation.
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Li H, Hai Y, Lim SY, Toledo N, Crecente-Campo J, Schalk D, Li L, Omange RW, Dacoba TG, Liu LR, Kashem MA, Wan Y, Liang B, Li Q, Rakasz E, Schultz-Darken N, Alonso MJ, Plummer FA, Whitney JB, Luo M. Mucosal antibody responses to vaccines targeting SIV protease cleavage sites or full-length Gag and Env proteins in Mauritian cynomolgus macaques. PLoS One 2018; 13:e0202997. [PMID: 30153293 PMCID: PMC6112674 DOI: 10.1371/journal.pone.0202997] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 08/13/2018] [Indexed: 02/07/2023] Open
Abstract
HIV mutates rapidly and infects CD4+ T cells, especially when they are activated. A vaccine targeting conserved, essential viral elements while limiting CD4+ T cell activation could be effective. Learning from natural immunity observed in a group of highly HIV-1 exposed seronegative Kenyan female sex workers, we are testing a novel candidate HIV vaccine targeting the 12 viral protease cleavage sites (PCSs) (the PCS vaccine), in comparison with a vaccine targeting full-length Gag and Env (the Gag/Env vaccine) in a Mauritian cynomolgus macaque/SIV model. In this study we evaluated these vaccines for induction of mucosal antibodies to SIV immunogens at the female genital tract. Bio-Plex and Western blot analyses of cervicovaginal lavage samples showed that both the PCS and Gag/Env vaccines can elicit mucosal IgG antibody responses to SIV immunogens. Significantly higher increase of anti-PCS antibodies was induced by the PCS vaccine than by the Gag/Env vaccine (p<0.0001). The effect of the mucosal antibody responses in protection from repeated low dose pathogenic SIVmac251 challenges is being evaluated.
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Affiliation(s)
- Hongzhao Li
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Yan Hai
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - So-Yon Lim
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States of America
| | - Nikki Toledo
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Jose Crecente-Campo
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Dane Schalk
- Scientific Protocol Implementation Unit, Wisconsin National Primate Research Center, Madison, WI, United States of America
| | - Lin Li
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - Robert W Omange
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Tamara G Dacoba
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Lewis R Liu
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Mohammad Abul Kashem
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
| | - Yanmin Wan
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States of America
| | - Binhua Liang
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, MB, Canada
| | - Qingsheng Li
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States of America
| | - Eva Rakasz
- Immunology Services Unit, Wisconsin National Primate Research Center, Madison, WI, United States of America
| | - Nancy Schultz-Darken
- Scientific Protocol Implementation Unit, Wisconsin National Primate Research Center, Madison, WI, United States of America
| | - Maria J Alonso
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Campus Vida, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Francis A Plummer
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.,National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
| | - James B Whitney
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States of America.,Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA, United States of America
| | - Ma Luo
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.,National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB, Canada
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van Buuren N, Tellinghuisen TL, Richardson CD, Kirkegaard K. Transmission genetics of drug-resistant hepatitis C virus. eLife 2018; 7:32579. [PMID: 29589830 PMCID: PMC5916564 DOI: 10.7554/elife.32579] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 03/22/2018] [Indexed: 12/11/2022] Open
Abstract
Antiviral development is plagued by drug resistance and genetic barriers to resistance are needed. For HIV and hepatitis C virus (HCV), combination therapy has proved life-saving. The targets of direct-acting antivirals for HCV infection are NS3/4A protease, NS5A phosphoprotein and NS5B polymerase. Differential visualization of drug-resistant and -susceptible RNA genomes within cells revealed that resistant variants of NS3/4A protease and NS5A phosphoprotein are cis-dominant, ensuring their direct selection from complex environments. Confocal microscopy revealed that RNA replication complexes are genome-specific, rationalizing the non-interaction of wild-type and variant products. No HCV antivirals yet display the dominance of drug susceptibility shown for capsid proteins of other viruses. However, effective inhibitors of HCV polymerase exact such high fitness costs for drug resistance that stable genome selection is not observed. Barriers to drug resistance vary with target biochemistry and detailed analysis of these barriers should lead to the use of fewer drugs. Viruses are simple organisms that consist of genetic information and a few types of proteins. They cannot replicate on their own, and instead hijack the molecular machinery of a host cell to produce more of themselves. Inside an infected cell, the genetic information of the virus is replicated and ‘read’ to create viral proteins. These components are then assembled to form a new generation of viruses. During this process, genetic errors may occur that lead to modifications in the viral proteins, and help the virus become resistant to treatment. For instance, a viral protein that used to be targeted by a drug can change slightly and not be recognized anymore. Currently, the most efficient way to fight drug resistance is to use combination therapy, where several drugs are given at the same time. This strategy is successful, for example to treat infections with the hepatitis C virus, but it is also expensive, especially for developing countries. An alternative approach is dominant-drug targeting, which exploits the fact that both drug-resistant and drug-susceptible viruses are ‘born’ in the same cell. There, the susceptible viruses can overwhelm and ‘mask’ the benefits of the resistant ones. For example, proteins from resistant strains, which are no longer detected by a treatment, can bind to proteins from susceptible viruses; drugs will still be able to recognize these resulting viral structures. The proteins that operate in such ways are potential dominant-drug targets. However, resistant and susceptible strains can also cohabit without any contacts if their proteins do not interact with each other. Now, van Buuren et al. screen several viral proteins, including one called NS5A, to test whether a dominant drug target exists for the hepatitis C virus. Only a few molecules of a drug that targets NS5A can stop the virus from growing. In theory, drug-bound NS5A proteins could block their non-drug-bound neighbors, but when these drugs have been used on their own, resistance quickly emerged. Experiments showed that NS5A is not a dominant drug target because the drug-resistant and drug-susceptible proteins do not mix. Unless ‘forced’ in the laboratory, NS5A proteins only bind to the ones produced by the same strain of virus. This explains why resistant viruses quickly take over when NS5A drugs are the sole treatment. However, other hepatitis C proteins, such as the HCV core protein, are known to mix during the assembly of the virus, and thus are likely be dominant drug targets.
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Affiliation(s)
- Nicholas van Buuren
- Department of Genetics, Stanford University School of Medicine, Stanford, United States
| | | | | | - Karla Kirkegaard
- Department of Genetics, Stanford University School of Medicine, Stanford, United States
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Su CTT, Kwoh CK, Verma CS, Gan SKE. Modeling the full length HIV-1 Gag polyprotein reveals the role of its p6 subunit in viral maturation and the effect of non-cleavage site mutations in protease drug resistance. J Biomol Struct Dyn 2017; 36:4366-4377. [PMID: 29237328 DOI: 10.1080/07391102.2017.1417160] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
HIV polyprotein Gag is increasingly found to contribute to protease inhibitor resistance. Despite its role in viral maturation and in developing drug resistance, there remain gaps in the knowledge of the role of certain Gag subunits (e.g. p6), and that of non-cleavage mutations in drug resistance. As p6 is flexible, it poses a problem for structural experiments, and is hence often omitted in experimental Gag structural studies. Nonetheless, as p6 is an indispensable component for viral assembly and maturation, we have modeled the full length Gag structure based on several experimentally determined constraints and studied its structural dynamics. Our findings suggest that p6 can mechanistically modulate Gag conformations. In addition, the full length Gag model reveals that allosteric communication between the non-cleavage site mutations and the first Gag cleavage site could possibly result in protease drug resistance, particularly in the absence of mutations in Gag cleavage sites. Our study provides a mechanistic understanding to the structural dynamics of HIV-1 Gag, and also proposes p6 as a possible drug target in anti-HIV therapy.
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Affiliation(s)
- Chinh Tran-To Su
- a Bioinformatics Institute , Agency for Science, Technology, and Research (A*STAR) , Singapore 138671 , Singapore
| | - Chee-Keong Kwoh
- b School of Computer Science and Engineering , Nanyang Technological University , Singapore 639798 , Singapore
| | - Chandra Shekhar Verma
- a Bioinformatics Institute , Agency for Science, Technology, and Research (A*STAR) , Singapore 138671 , Singapore
| | - Samuel Ken-En Gan
- a Bioinformatics Institute , Agency for Science, Technology, and Research (A*STAR) , Singapore 138671 , Singapore.,c p53 Laboratory , Agency for Science, Technology, and Research (A*STAR) , Singapore 138648 , Singapore
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Wapling J, Srivastava S, Shehu-Xhilaga M, Tachedjian G. Targeting Human Immunodeficiency Virus Type 1 Assembly, Maturation and Budding. Drug Target Insights 2017. [DOI: 10.1177/117739280700200020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Johanna Wapling
- Molecular Interactions Group, Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia
- Department of Microbiology, Monash University, Clayton, Victoria 3168, Australia
| | - Seema Srivastava
- Molecular Interactions Group, Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia
| | - Miranda Shehu-Xhilaga
- Department of Medicine, Monash University, Prahran, Victoria 3181, Australia
- Infectious Diseases Unit, Alfred Hospital, Prahran, Victoria 3181, Australia
| | - Gilda Tachedjian
- Molecular Interactions Group, Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia
- Department of Microbiology, Monash University, Clayton, Victoria 3168, Australia
- Department of Medicine, Monash University, Prahran, Victoria 3181, Australia
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The multiple roles of the nucleocapsid in retroviral RNA conversion into proviral DNA by reverse transcriptase. Biochem Soc Trans 2017; 44:1427-1440. [PMID: 27911725 DOI: 10.1042/bst20160101-t] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/08/2016] [Accepted: 08/17/2016] [Indexed: 01/27/2023]
Abstract
Retroviruses are enveloped plus-strand RNA viruses that can cause cancer, immunodeficiency and neurological disorder in human and animals. Retroviruses have several unique properties, such as a genomic RNA in a dimeric form found in the virus, and a replication strategy called 'copy-and-paste' during which the plus-strand genomic RNA is converted into a double-stranded DNA, subsequently integrated into the cellular genome. Two essential viral enzymes, reverse transcriptase (RT) and integrase (IN), direct this 'copy-and-paste' replication. RT copies the genomic RNA generating the double-stranded proviral DNA, while IN catalyzes proviral DNA integration into the cellular DNA, then called the provirus. In that context, a major component of the virion core, the nucleocapsid protein (NC), was found to be a potent nucleic-acid chaperone that assists RT during the conversion of the genomic RNA into proviral DNA. Here we briefly review the interplay of NC with viral nucleic-acids, which enables rapid and faithful folding and hybridization of complementary sequences, and with active RT thus providing assistance to the synthesis of the complete proviral DNA. Because of its multiple roles in retrovirus replication, NC could be viewed as a two-faced Janus-chaperone acting on viral nucleic-acids and enzymes.
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The Second-Generation Maturation Inhibitor GSK3532795 Maintains Potent Activity Toward HIV Protease Inhibitor-Resistant Clinical Isolates. J Acquir Immune Defic Syndr 2017; 75:52-60. [PMID: 28234686 PMCID: PMC5389583 DOI: 10.1097/qai.0000000000001304] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Supplemental Digital Content is Available in the Text. Background: Protease inhibitor (PI)-resistant HIV-1 isolates with primary substitutions in protease (PR) and secondary substitutions in Gag could potentially exhibit cross-resistance to maturation inhibitors. We evaluated the second-generation maturation inhibitor, GSK3532795, for activity toward clinical isolates with genotypic and phenotypic characteristics associated with PI resistance (longitudinal). Methods: Longitudinal clinical isolates from 15 PI-treated patients and 7 highly PI-resistant (nonlongitudinal) viruses containing major and minor PI resistance-associated mutations were evaluated for GSK3532795 sensitivity. Phenotypic sensitivity was determined using the PhenoSense Gag/PR assay (Monogram Biosciences) or in-house single- and multiple-cycle assays. Changes from baseline [CFB; ratio of post- to pre-treatment FC-IC50 (fold-change in IC50 versus wild-type virus)] <3 were considered to be within the no-effect level. Results: All nonlongitudinal viruses tested were sensitive to GSK3532795 (FC-IC50 range 0.16–0.68). Among longitudinal isolates, all post-PI treatment samples had major PI resistance-associated mutations in PR and 17/21 had PI resistance-associated changes in Gag. Nineteen of the 21 post-PI treatment samples had GSK3532795 CFB <3. Median (range) CFB was 0.83 (0.05–27.4) [Monogram (11 patients)] and 1.5 (1.0–2.2) [single-cycle (4 patients)]. The 2 post-PI treatment samples showing GSK3532795 CFB >3 (Monogram) were retested using single- and multiple-cycle assays. Neither sample had meaningful sensitivity changes in the multiple-cycle assay. Gag changes were not associated with an increased GSK3532795 CFB. Conclusions: GSK3532795 maintained antiviral activity against PI-resistant isolates with emergent PR and/or Gag mutations. This finding supports continued development of GSK3532795 in treatment-experienced patients with or without previous PI therapy.
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Lin Z, Cantone J, Lu H, Nowicka-Sans B, Protack T, Yuan T, Yang H, Liu Z, Drexler D, Regueiro-Ren A, Meanwell NA, Cockett M, Krystal M, Lataillade M, Dicker IB. Mechanistic Studies and Modeling Reveal the Origin of Differential Inhibition of Gag Polymorphic Viruses by HIV-1 Maturation Inhibitors. PLoS Pathog 2016; 12:e1005990. [PMID: 27893830 PMCID: PMC5125710 DOI: 10.1371/journal.ppat.1005990] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 10/11/2016] [Indexed: 12/27/2022] Open
Abstract
HIV-1 maturation inhibitors (MIs) disrupt the final step in the HIV-1 protease-mediated cleavage of the Gag polyprotein between capsid p24 capsid (CA) and spacer peptide 1 (SP1), leading to the production of infectious virus. BMS-955176 is a second generation MI with improved antiviral activity toward polymorphic Gag variants compared to a first generation MI bevirimat (BVM). The underlying mechanistic reasons for the differences in polymorphic coverage were studied using antiviral assays, an LC/MS assay that quantitatively characterizes CA/SP1 cleavage kinetics of virus like particles (VLPs) and a radiolabel binding assay to determine VLP/MI affinities and dissociation kinetics. Antiviral assay data indicates that BVM does not achieve 100% inhibition of certain polymorphs, even at saturating concentrations. This results in the breakthrough of infectious virus (partial antagonism) regardless of BVM concentration. Reduced maximal percent inhibition (MPI) values for BVM correlated with elevated EC50 values, while rates of HIV-1 protease cleavage at CA/SP1 correlated inversely with the ability of BVM to inhibit HIV-1 Gag polymorphic viruses: genotypes with more rapid CA/SP1 cleavage kinetics were less sensitive to BVM. In vitro inhibition of wild type VLP CA/SP1 cleavage by BVM was not maintained at longer cleavage times. BMS-955176 exhibited greatly improved MPI against polymorphic Gag viruses, binds to Gag polymorphs with higher affinity/longer dissociation half-lives and exhibits greater time-independent inhibition of CA/SP1 cleavage compared to BVM. Virological (MPI) and biochemical (CA/SP1 cleavage rates, MI-specific Gag affinities) data were used to create an integrated semi-quantitative model that quantifies CA/SP1 cleavage rates as a function of both MI and Gag polymorph. The model outputs are in accord with in vitro antiviral observations and correlate with observed in vivo MI efficacies. Overall, these findings may be useful to further understand antiviral profiles and clinical responses of MIs at a basic level, potentially facilitating further improvements to MI potency and coverage.
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Affiliation(s)
- Zeyu Lin
- Departments of Virology, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Joseph Cantone
- Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Hao Lu
- Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Beata Nowicka-Sans
- Departments of Virology, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Tricia Protack
- Departments of Virology, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Tian Yuan
- Discovery Chemistry Platforms, Princeton, New Jersey, United States of America
| | - Hong Yang
- Discovery Chemistry Platforms, Princeton, New Jersey, United States of America
| | - Zheng Liu
- Discovery Chemistry, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Dieter Drexler
- Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Alicia Regueiro-Ren
- Discovery Chemistry, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Nicholas A. Meanwell
- Discovery Chemistry, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Mark Cockett
- Departments of Virology, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Mark Krystal
- Departments of Virology, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Max Lataillade
- Global Clinical Development, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
| | - Ira B. Dicker
- Departments of Virology, Bristol-Myers Squibb Research & Development, Wallingford, Connecticut, United States of America
- * E-mail: ,
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Structural Maturation of HIV-1 Reverse Transcriptase-A Metamorphic Solution to Genomic Instability. Viruses 2016; 8:v8100260. [PMID: 27690082 PMCID: PMC5086598 DOI: 10.3390/v8100260] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/12/2016] [Indexed: 12/13/2022] Open
Abstract
Human immunodeficiency virus 1 (HIV-1) reverse transcriptase (RT)—a critical enzyme of the viral life cycle—undergoes a complex maturation process, required so that a pair of p66 precursor proteins can develop conformationally along different pathways, one evolving to form active polymerase and ribonuclease H (RH) domains, while the second forms a non-functional polymerase and a proteolyzed RH domain. These parallel maturation pathways rely on the structural ambiguity of a metamorphic polymerase domain, for which the sequence–structure relationship is not unique. Recent nuclear magnetic resonance (NMR) studies utilizing selective labeling techniques, and structural characterization of the p66 monomer precursor have provided important insights into the details of this maturation pathway, revealing many aspects of the three major steps involved: (1) domain rearrangement; (2) dimerization; and (3) subunit-selective RH domain proteolysis. This review summarizes the major structural changes that occur during the maturation process. We also highlight how mutations, often viewed within the context of the mature RT heterodimer, can exert a major influence on maturation and dimerization. It is further suggested that several steps in the RT maturation pathway may provide attractive targets for drug development.
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Hanne J, Göttfert F, Schimer J, Anders-Össwein M, Konvalinka J, Engelhardt J, Müller B, Hell SW, Kräusslich HG. Stimulated Emission Depletion Nanoscopy Reveals Time-Course of Human Immunodeficiency Virus Proteolytic Maturation. ACS NANO 2016; 10:8215-8222. [PMID: 27517329 DOI: 10.1021/acsnano.6b03850] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Concomitant with human immunodeficiency virus type 1 (HIV-1) budding from a host cell, cleavage of the structural Gag polyproteins by the viral protease (PR) triggers complete remodeling of virion architecture. This maturation process is essential for virus infectivity. Electron tomography provided structures of immature and mature HIV-1 with a diameter of 120-140 nm, but information about the sequence and dynamics of structural rearrangements is lacking. Here, we employed super-resolution STED (stimulated emission depletion) fluorescence nanoscopy of HIV-1 carrying labeled Gag to visualize the virion architecture. The incomplete Gag lattice of immature virions was clearly distinguishable from the condensed distribution of mature protein subunits. Synchronized activation of PR within purified particles by photocleavage of a caged PR inhibitor enabled time-resolved in situ observation of the induction of proteolysis and maturation by super-resolution microscopy. This study shows the rearrangement of subviral structures in a super-resolution light microscope over time, outwitting phototoxicity and fluorophore bleaching through synchronization of a biological process by an optical switch.
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Affiliation(s)
- Janina Hanne
- Department of Infectious Diseases, Virology, Heidelberg University , Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
- Optical Nanoscopy Division, German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Fabian Göttfert
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry , Am Fassberg 11, 37077 Göttingen, Germany
| | - Jiří Schimer
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Gilead Sciences and IOCB Research Center , Flemingovo n.2, 166 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University in Prague , Hlavova 8, 12843 Prague 2, Czech Republic
| | - Maria Anders-Össwein
- Department of Infectious Diseases, Virology, Heidelberg University , Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Jan Konvalinka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Gilead Sciences and IOCB Research Center , Flemingovo n.2, 166 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University in Prague , Hlavova 8, 12843 Prague 2, Czech Republic
| | - Johann Engelhardt
- Optical Nanoscopy Division, German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Barbara Müller
- Department of Infectious Diseases, Virology, Heidelberg University , Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
- Molecular Medicine Partnership Unit , Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Stefan W Hell
- Optical Nanoscopy Division, German Cancer Research Center (DKFZ) , Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry , Am Fassberg 11, 37077 Göttingen, Germany
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, Heidelberg University , Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
- Molecular Medicine Partnership Unit , Meyerhofstrasse 1, 69117 Heidelberg, Germany
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Abbadessa D, Smurthwaite CA, Reed CW, Wolkowicz R. A Single-Cell Platform for Monitoring Viral Proteolytic Cleavage in Different Cellular Compartments. BIOCHEMISTRY INSIGHTS 2016; 8:23-31. [PMID: 27688710 PMCID: PMC5034881 DOI: 10.4137/bci.s30379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/17/2016] [Accepted: 08/19/2016] [Indexed: 11/08/2022]
Abstract
Infectious diseases affect human health despite advances in biomedical research and drug discovery. Among these, viruses are especially difficult to tackle due to the sudden transfer from animals to humans, high mutational rates, resistance to current treatments, and the intricacies of their molecular interactions with the host. As an example of these interactions, we describe a cell-based approach to monitor specific proteolytic events executed by either the viral-encoded protease or by host proteins on the virus. We then emphasize the significance of examining proteolysis within the subcellular compartment where cleavage occurs naturally. We show the power of stable expression, highlighting the usefulness of the cell-based multiplexed approach, which we have adapted to two independent assays previously developed to monitor (a) the activity of the HIV-1-encoded protease or (b) the cleavage of the HIV-1-encoded envelope protein by the host. Multiplexing was achieved by mixing cells each carrying a different assay or, alternatively, by engineering cells expressing two assays. Multiplexing relies on the robustness of the individual assays and their clear discrimination, further enhancing screening capabilities in an attempt to block proteolytic events required for viral infectivity and spread.
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Affiliation(s)
- Darin Abbadessa
- Department of Biology, San Diego State University, San Diego, CA, USA
| | | | - Connor W Reed
- Department of Biology, San Diego State University, San Diego, CA, USA
| | - Roland Wolkowicz
- Department of Biology, San Diego State University, San Diego, CA, USA
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Sabino Cunha M, Lima Sampaio T, Peterlin BM, Jesus da Costa L. A Truncated Nef Peptide from SIVcpz Inhibits the Production of HIV-1 Infectious Progeny. Viruses 2016; 8:v8070189. [PMID: 27399760 PMCID: PMC4974524 DOI: 10.3390/v8070189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/08/2016] [Accepted: 06/14/2016] [Indexed: 12/02/2022] Open
Abstract
Nef proteins from all primate Lentiviruses, including the simian immunodeficiency virus of chimpanzees (SIVcpz), increase viral progeny infectivity. However, the function of Nef involved with the increase in viral infectivity is still not completely understood. Nonetheless, until now, studies investigating the functions of Nef from SIVcpz have been conducted in the context of the HIV-1 proviruses. In an attempt to investigate the role played by Nef during the replication cycle of an SIVcpz, a Nef-defective derivative was obtained from the SIVcpzWTGab2 clone by introducing a frame shift mutation at a unique restriction site within the nef sequence. This nef-deleted clone expresses an N-terminal 74-amino acid truncated peptide of Nef and was named SIVcpz-tNef. We found that the SIVcpz-tNef does not behave as a classic nef-deleted HIV-1 or simian immunodeficiency virus of macaques SIVmac. Markedly, SIVcpz-tNef progeny from both Hek-293T and Molt producer cells were completely non-infectious. Moreover, the loss in infectivity of SIVcpz-tNef correlated with the inhibition of Gag and GagPol processing. A marked accumulation of Gag and very low levels of reverse transcriptase were detected in viral lysates. Furthermore, these observations were reproduced once the tNef peptide was expressed in trans both in SIVcpzΔNef and HIV-1WT expressing cells, demonstrating that the truncated peptide is a dominant negative for viral processing and infectivity for both SIVcpz and HIV-1. We demonstrated that the truncated Nef peptide binds to GagPol outside the protease region and by doing so probably blocks processing of both GagPol and Gag precursors at a very early stage. This study demonstrates for the first time that naturally-occurring Nef peptides can potently block lentiviral processing and infectivity.
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Affiliation(s)
- Marcela Sabino Cunha
- Departamento de Virologia-Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373-CCS-Bloco I, Rio de Janeiro 21941-902, Brazil.
| | - Thatiane Lima Sampaio
- Departamento de Virologia-Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373-CCS-Bloco I, Rio de Janeiro 21941-902, Brazil.
| | - B Matija Peterlin
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, 533 Parnassus Avenue, San Francisco, CA 94143, USA.
| | - Luciana Jesus da Costa
- Departamento de Virologia-Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373-CCS-Bloco I, Rio de Janeiro 21941-902, Brazil.
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Nowicka-Sans B, Protack T, Lin Z, Li Z, Zhang S, Sun Y, Samanta H, Terry B, Liu Z, Chen Y, Sin N, Sit SY, Swidorski JJ, Chen J, Venables BL, Healy M, Meanwell NA, Cockett M, Hanumegowda U, Regueiro-Ren A, Krystal M, Dicker IB. Identification and Characterization of BMS-955176, a Second-Generation HIV-1 Maturation Inhibitor with Improved Potency, Antiviral Spectrum, and Gag Polymorphic Coverage. Antimicrob Agents Chemother 2016; 60:3956-69. [PMID: 27090171 PMCID: PMC4914680 DOI: 10.1128/aac.02560-15] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 12/03/2015] [Indexed: 12/26/2022] Open
Abstract
BMS-955176 is a second-generation human immunodeficiency virus type 1 (HIV-1) maturation inhibitor (MI). A first-generation MI, bevirimat, showed clinical efficacy in early-phase studies, but ∼50% of subjects had viruses with reduced susceptibility associated with naturally occurring polymorphisms in Gag near the site of MI action. MI potency was optimized using a panel of engineered reporter viruses containing site-directed polymorphic changes in Gag that reduce susceptibility to bevirimat (including V362I, V370A/M/Δ, and T371A/Δ), leading incrementally to the identification of BMS-955176. BMS-955176 exhibits potent activity (50% effective concentration [EC50], 3.9 ± 3.4 nM [mean ± standard deviation]) toward a library (n = 87) of gag/pr recombinant viruses representing 96.5% of subtype B polymorphic Gag diversity near the CA/SP1 cleavage site. BMS-955176 exhibited a median EC50 of 21 nM toward a library of subtype B clinical isolates assayed in peripheral blood mononuclear cells (PBMCs). Potent activity was maintained against a panel of reverse transcriptase, protease, and integrase inhibitor-resistant viruses, with EC50s similar to those for the wild-type virus. A 5.4-fold reduction in EC50 occurred in the presence of 40% human serum plus 27 mg/ml of human serum albumin (HSA), which corresponded well to an in vitro measurement of 86% human serum binding. Time-of-addition and pseudotype reporter virus studies confirm a mechanism of action for the compound that occurs late in the virus replication cycle. BMS-955176 inhibits HIV-1 protease cleavage at the CA/SP1 junction within Gag in virus-like particles (VLPs) and in HIV-1-infected cells, and it binds reversibly and with high affinity to assembled Gag in purified HIV-1 VLPs. Finally, in vitro combination studies showed no antagonistic interactions with representative antiretrovirals (ARVs) of other mechanistic classes. In conclusion, BMS-955176 is a second-generation MI with potent in vitro anti-HIV-1 activity and a greatly improved preclinical profile compared to that of bevirimat.
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Affiliation(s)
- Beata Nowicka-Sans
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Tricia Protack
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Zeyu Lin
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Zhufang Li
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Sharon Zhang
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Yongnian Sun
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Himadri Samanta
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Brian Terry
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Zheng Liu
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Yan Chen
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Ny Sin
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Sing-Yuen Sit
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Jacob J Swidorski
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Jie Chen
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Brian L Venables
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Matthew Healy
- Bristol-Myers Squibb, Research and Development, Department of Genomics, Wallingford, Connecticut, USA
| | - Nicholas A Meanwell
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Mark Cockett
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Umesh Hanumegowda
- Bristol-Myers Squibb, Research and Development, Department of Preclinical Optimization, Wallingford, Connecticut, USA
| | - Alicia Regueiro-Ren
- Bristol-Myers Squibb, Research and Development, Department of Discovery Chemistry, Wallingford, Connecticut, USA
| | - Mark Krystal
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
| | - Ira B Dicker
- Bristol-Myers Squibb, Research and Development, Department of Virology, Wallingford, Connecticut, USA
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47
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The Race against Protease Activation Defines the Role of ESCRTs in HIV Budding. PLoS Pathog 2016; 12:e1005657. [PMID: 27280284 PMCID: PMC4900648 DOI: 10.1371/journal.ppat.1005657] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 05/03/2016] [Indexed: 11/26/2022] Open
Abstract
HIV virions assemble on the plasma membrane and bud out of infected cells using interactions with endosomal sorting complexes required for transport (ESCRTs). HIV protease activation is essential for maturation and infectivity of progeny virions, however, the precise timing of protease activation and its relationship to budding has not been well defined. We show that compromised interactions with ESCRTs result in delayed budding of virions from host cells. Specifically, we show that Gag mutants with compromised interactions with ALIX and Tsg101, two early ESCRT factors, have an average budding delay of ~75 minutes and ~10 hours, respectively. Virions with inactive proteases incorporated the full Gag-Pol and had ~60 minutes delay in budding. We demonstrate that during budding delay, activated proteases release critical HIV enzymes back to host cytosol leading to production of non-infectious progeny virions. To explain the molecular mechanism of the observed budding delay, we modulated the Pol size artificially and show that virion release delays are size-dependent and also show size-dependency in requirements for Tsg101 and ALIX. We highlight the sensitivity of HIV to budding “on-time” and suggest that budding delay is a potent mechanism for inhibition of infectious retroviral release. ESCRTs are implicated in cellular processes which require fission of budding membranes. Likely the most studied of these processes is the HIV-ESCRT interactions. The canonical view is that interference with ESCRT recruitment results in a late budding arrest of virions at the plasma membrane and this mechanistic view of ESCRTs has shaped our understanding of their function in almost all cell biology. In this manuscript, we present a full kinetic analysis of HIV virion release under all known mutations in Gag that affect HIV-ESCRT interactions. Our data show that contrary to the canonical view, a defect in ESCRT recruitment does not inhibit virion budding, however it creates a delay. We further show that during budding delay, activated proteases release critical HIV enzymes back to host cytosol, leading to budding of non-infectious progeny virions. We suggest that budding delay is a potent mechanism for inhibition of infectious retroviral release and can be the basis for developing antiviral treatments which slow the budding process and therefore disproportionally affect infectious retroviral release. We also suggest that such budding delay may be one of the mechanisms underlying cellular innate immune responses which inhibit the spread of retroviral infection.
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Liu Z, Swidorski JJ, Nowicka-Sans B, Terry B, Protack T, Lin Z, Samanta H, Zhang S, Li Z, Parker DD, Rahematpura S, Jenkins S, Beno BR, Krystal M, Meanwell NA, Dicker IB, Regueiro-Ren A. C-3 benzoic acid derivatives of C-3 deoxybetulinic acid and deoxybetulin as HIV-1 maturation inhibitors. Bioorg Med Chem 2016; 24:1757-70. [PMID: 26968652 DOI: 10.1016/j.bmc.2016.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 02/21/2016] [Accepted: 03/01/2016] [Indexed: 11/28/2022]
Abstract
A series of C-3 phenyl- and heterocycle-substituted derivatives of C-3 deoxybetulinic acid and C-3 deoxybetulin was designed and synthesized as HIV-1 maturation inhibitors (MIs) and evaluated for their antiviral activity and cytotoxicity in cell culture. A 4-subsituted benzoic acid moiety was identified as an advantageous replacement for the 3'3'-dimethylsuccinate moiety present in previously disclosed MIs that illuminates new aspects of the topography of the pharmacophore. The new analogs exhibit excellent in vitro antiviral activity against wild-type (wt) virus and a lower serum shift when compared with the prototypical HIV-1 MI bevirimat (1, BVM), the first MI to be evaluated in clinical studies. Compound 9a exhibits comparable cell culture potency toward wt virus as 1 (WT EC50=16 nM for 9a compared to 10nM for 1). However, the potency of 9a is less affected by the presence of human serum, while the compound displays a similar pharmacokinetic profile in rats to 1. Hence 9a, the 4-benzoic acid derivative of deoxybetulinic acid, represents a new starting point from which to explore the design of a 2nd generation MI.
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Affiliation(s)
- Zheng Liu
- Department of Discovery Chemistry, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA.
| | - Jacob J Swidorski
- Department of Discovery Chemistry, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Beata Nowicka-Sans
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Brian Terry
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Tricia Protack
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Zeyu Lin
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Himadri Samanta
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Sharon Zhang
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Zhufang Li
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Dawn D Parker
- Department of Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Sandhya Rahematpura
- Department of Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Susan Jenkins
- Department of Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Brett R Beno
- Department of Computer-Assisted Drug Design, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Mark Krystal
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Nicholas A Meanwell
- Department of Discovery Chemistry, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Ira B Dicker
- Department of Virology, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA
| | - Alicia Regueiro-Ren
- Department of Discovery Chemistry, Bristol-Myers Squibb Research and Development, 5 Research Parkway, Wallingford, CT 06492, USA.
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49
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Kitidee K, Khamaikawin W, Thongkum W, Tawon Y, Cressey TR, Jevprasesphant R, Kasinrerk W, Tayapiwatana C. Expedient screening for HIV-1 protease inhibitors using a simplified immunochromatographic assay. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 1021:153-158. [PMID: 26490422 DOI: 10.1016/j.jchromb.2015.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 10/02/2015] [Accepted: 10/06/2015] [Indexed: 11/19/2022]
Abstract
A colloidal gold-based immunochromatographic (IC) strip test was developed and validated for the detection of HIV-1 protease (HIV-PR) activity and inhibitory effect of HIV-PR inhibitors (PIs). It is a unique 'two-step' process requiring the combination of proteolysis of HIV-PR and an immunochromatographic reaction. Monoclonal antibodies to the free C-terminus of HIV matrix protein (HIV-MA) conjugated to gold particles and a monoclonal antibody against intact and cleaved forms of the HIV-MA are immobilized on the 'Test'-line of the IC strip. Using lopinavir, a potent HIV protease inhibitor, the IC-strip was optimized to detect inhibitory activity against HIV-protease. At a lopinavir concentration of 1000ng/mL (its suggested minimum effective concentration), a HIV-PRH6 concentration of 6mg/mL and incubation period of 60min were the optimal conditions. A preliminary comparison between a validated high-performance liquid chromatography assay and the IC-strip to semi-quantify HIV protease inhibitor concentrations (lopinavir and atazanavir) demonstrated good agreement. This simplified method is suitable for the rapid screening of novel protease inhibitors for future therapeutic use. Moreover, the IC strip could also be optimized to semi-quantify PIs concentrations in plasma samples.
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Affiliation(s)
- Kuntida Kitidee
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
| | - Wannisa Khamaikawin
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Weeraya Thongkum
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; i+MED Laboratories Company Limited, Bangkok, Thailand
| | - Yardpiroon Tawon
- Program for HIV Prevention and Treatment (PHPT/IRD 174), Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Tim R Cressey
- Program for HIV Prevention and Treatment (PHPT/IRD 174), Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; Harvard T.H Chan School of Public Health, Boston, MA 02115, USA
| | | | - Watchara Kasinrerk
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; Biomedical Technology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency at the Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Chatchai Tayapiwatana
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand; Center of Biomolecular Therapy and Diagnostic, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai 50200, Thailand.
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50
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Laco GS. HIV-1 protease substrate-groove: Role in substrate recognition and inhibitor resistance. Biochimie 2015; 118:90-103. [PMID: 26300060 DOI: 10.1016/j.biochi.2015.08.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/18/2015] [Indexed: 11/17/2022]
Abstract
A key target in the treatment of HIV-1/AIDS has been the viral protease. Here we first studied in silico the evolution of protease resistance. Primary active site resistance mutations were found to weaken interactions between protease and both inhibitor and substrate P4-P4' residues. We next studied the effects of secondary resistance mutations, often distant from the active site, on protease binding to inhibitors and substrates. Those secondary mutations contributed to the rise of multi-drug resistance while also enhancing viral replicative capacity. Here many secondary resistance mutations were found in the HIV-1 protease substrate-grooves, one on each face of the symmetrical protease dimer. The protease active site binds substrate P4-P4' residues, while the substrate-groove allows the protease to bind residues P12-P5/P5'-P12', for a total of twenty-four residues. The substrate-groove secondary resistance mutations were found to compensate for the loss of interactions between the inhibitor resistant protease active site and substrate P4-P4' residues, due to primary resistance mutations, by increasing interactions with substrate P12-P5/P5'-P12' residues. In vitro experiments demonstrated that a multi-drug resistant protease with substrate-groove resistance mutations was slower than wild-type protease in cleaving a peptide substrate, which did not allow for substrate-groove interactions, while it had similar activity as wild-type protease when using a Gag polyprotein in which cleavage-site P12-P5/P5'-P12' residues could be bound by the protease substrate-grooves. When the Gag MA/CA cleavage site P12-P5/P5'-P12' residues were mutated the multi-drug resistant protease cleaved the mutant Gag significantly slower, indicating the importance of the protease S-grooves in binding to substrate.
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Affiliation(s)
- Gary S Laco
- Laboratory of Computational and Molecular Biochemistry, The Roskamp Institute, Sarasota, FL, USA.
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