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Gien H, Morse M, McCauley MJ, Rouzina I, Gorelick RJ, Williams MC. Cationic Residues of the HIV-1 Nucleocapsid Protein Enable DNA Condensation to Maintain Viral Core Particle Stability during Reverse Transcription. Viruses 2024; 16:872. [PMID: 38932164 PMCID: PMC11209390 DOI: 10.3390/v16060872] [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: 03/29/2024] [Revised: 04/30/2024] [Accepted: 05/23/2024] [Indexed: 06/28/2024] Open
Abstract
The HIV-1 nucleocapsid protein (NC) is a multifunctional viral protein necessary for HIV-1 replication. Recent studies have demonstrated that reverse transcription (RT) completes in the intact viral capsid, and the timing of RT and uncoating are correlated. How the small viral core stably contains the ~10 kbp double stranded (ds) DNA product of RT, and the role of NC in this process, are not well understood. We showed previously that NC binds and saturates dsDNA in a non-specific electrostatic binding mode that triggers uniform DNA self-attraction, condensing dsDNA into a tight globule against extending forces up to 10 pN. In this study, we use optical tweezers and atomic force microscopy to characterize the role of NC's basic residues in dsDNA condensation. Basic residue mutations of NC lead to defective interaction with the dsDNA substrate, with the constant force plateau condensation observed with wild-type (WT) NC missing or diminished. These results suggest that NC's high positive charge is essential to its dsDNA condensing activity, and electrostatic interactions involving NC's basic residues are responsible in large part for the conformation, size, and stability of the dsDNA-protein complex inside the viral core. We observe DNA re-solubilization and charge reversal in the presence of excess NC, consistent with the electrostatic nature of NC-induced DNA condensation. Previous studies of HIV-1 replication in the presence of the same cationic residue mutations in NC showed significant defects in both single- and multiple-round viral infectivity. Although NC participates in many stages of viral replication, our results are consistent with the hypothesis that cationic residue mutations inhibit genomic DNA condensation, resulting in increased premature capsid uncoating and contributing to viral replication defects.
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Affiliation(s)
- Helena Gien
- Department of Physics, Northeastern University, Boston, MA 02115, USA; (H.G.); (M.M.); (M.J.M.)
| | - Michael Morse
- Department of Physics, Northeastern University, Boston, MA 02115, USA; (H.G.); (M.M.); (M.J.M.)
| | - Micah J. McCauley
- Department of Physics, Northeastern University, Boston, MA 02115, USA; (H.G.); (M.M.); (M.J.M.)
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA;
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA;
| | - Mark C. Williams
- Department of Physics, Northeastern University, Boston, MA 02115, USA; (H.G.); (M.M.); (M.J.M.)
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2
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Burdick RC, Morse M, Rouzina I, Williams MC, Hu WS, Pathak VK. HIV-1 uncoating requires long double-stranded reverse transcription products. SCIENCE ADVANCES 2024; 10:eadn7033. [PMID: 38657061 PMCID: PMC11042746 DOI: 10.1126/sciadv.adn7033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 03/21/2024] [Indexed: 04/26/2024]
Abstract
HIV-1 cores, which contain the viral genome and replication machinery, must disassemble (uncoat) during viral replication. However, the viral and host factors that trigger uncoating remain unidentified. Recent studies show that infectious cores enter the nucleus and uncoat near the site of integration. Here, we show that efficient uncoating of nuclear cores requires synthesis of a double-stranded DNA (dsDNA) genome >3.5 kb and that the efficiency of uncoating correlates with genome size. Core disruption by capsid inhibitors releases viral DNA, some of which integrates. However, most of the viral DNA is degraded, indicating that the intact core safeguards viral DNA. Atomic force microscopy and core content estimation reveal that synthesis of full-length genomic dsDNA induces substantial internal strain on the core to promote uncoating. We conclude that HIV-1 cores protect viral DNA from degradation by host factors and that synthesis of long double-stranded reverse transcription products is required to trigger efficient HIV-1 uncoating.
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Affiliation(s)
- Ryan C. Burdick
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, 21702, USA
| | - Michael Morse
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA
| | - Mark C. Williams
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Wei-Shau Hu
- Viral Recombination Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, 21702, USA
| | - Vinay K. Pathak
- Viral Mutation Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, 21702, USA
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Zgheib S, Taha N, Zeiger M, Glushonkov O, Lequeu T, Anton H, Didier P, Boutant E, Mély Y, Réal E. The human cellular protein NoL12 is a specific partner of the HIV-1 nucleocapsid protein NCp7. J Virol 2023; 97:e0004023. [PMID: 37695057 PMCID: PMC10537728 DOI: 10.1128/jvi.00040-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 07/12/2023] [Indexed: 09/12/2023] Open
Abstract
The human immunodeficiency virus-1 (HIV-1) nucleocapsid protein (NCp7) is a nucleic acid chaperone protein with two highly conserved zinc fingers. To exert its key roles in the viral cycle, NCp7 interacts with several host proteins. Among them, the human NoL12 protein (hNoL12) was previously identified in genome wide screens as a potential partner of NCp7. hNoL12 is a highly conserved 25 kDa nucleolar RNA-binding protein implicated in the 5'end processing of ribosomal RNA in the nucleolus and thus in the assembly and maturation of ribosomes. In this work, we confirmed the NCp7/hNoL12 interaction in cells by Förster resonance energy transfer visualized by Fluorescence Lifetime Imaging Microscopy and co-immunoprecipitation. The interaction between NCp7 and hNoL12 was found to strongly depend on their both binding to RNA, as shown by the loss of interaction when the cell lysates were pretreated with RNase. Deletion mutants of hNoL12 were tested for their co-immunoprecipitation with NCp7, leading to the identification of the exonuclease domain of hNoL12 as the binding domain for NCp7. Finally, the interaction with hNoL12 was found to be specific of the mature NCp7 and to require NCp7 basic residues. IMPORTANCE HIV-1 mature nucleocapsid (NCp7) results from the maturation of the Gag precursor in the viral particle and is thus mostly abundant in the first phase of the infection which ends with the genomic viral DNA integration in the cell genome. Most if not all the nucleocapsid partners identified so far are not specific of the mature form. We described here the specific interaction in the nucleolus between NCp7 and the human nucleolar protein 12, a protein implicated in ribosomal RNA maturation and DNA damage response. This interaction takes place in the cell nucleolus, a subcellular compartment where NCp7 accumulates. The absence of binding between hNoL12 and Gag makes hNoL12 one of the few known specific cellular partners of NCp7.
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Affiliation(s)
- Sarwat Zgheib
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Nedal Taha
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Manon Zeiger
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Oleksandr Glushonkov
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Thiebault Lequeu
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Halina Anton
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Pascal Didier
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Emmanuel Boutant
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Yves Mély
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Eléonore Réal
- CNRS, Laboratoire de Bioimagerie et Pathologies - LBP, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
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4
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Monette A, Niu M, Nijhoff Asser M, Gorelick RJ, Mouland AJ. Scaffolding viral protein NC nucleates phase separation of the HIV-1 biomolecular condensate. Cell Rep 2022; 40:111251. [PMID: 36001979 DOI: 10.1016/j.celrep.2022.111251] [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] [Received: 12/23/2021] [Revised: 06/20/2022] [Accepted: 08/01/2022] [Indexed: 11/26/2022] Open
Abstract
Membraneless biomolecular condensates (BMCs) contribute to the replication of a growing number of viruses but remain to be functionally characterized. Previously, we demonstrated that pan-retroviral nucleocapsid (NC) proteins phase separated into condensates regulating virus assembly. Here we discover that intrinsically disordered human immunodeficiency virus-type 1 (HIV-1) core proteins condense with the viral genomic RNA (vRNA) to assemble as BMCs attaining a geometry characteristic of viral reverse transcription complexes. We explore the predisposition, mechanisms, and pharmacologic sensitivity of HIV-1 core BMCs in living cells. HIV-1 vRNA-interacting NC condensates were found to be scaffolds onto which client capsid, reverse transcriptase, and integrase condensates assemble. HIV-1 core BMCs exhibit fundamental characteristics of BMCs and are drug-sensitive. Lastly, protease-mediated maturation of Gag and Gag-Pol precursor proteins yield abundant and visible BMCs in cells. This study redefines HIV-1 core components as fluid BMCs and advances our understanding of the nature of viral cores during ingress.
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Affiliation(s)
- Anne Monette
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada.
| | - Meijuan Niu
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada
| | - Maya Nijhoff Asser
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Lab, Lady Davis Institute at the Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada; Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 2B4, Canada; Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada.
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5
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Gien H, Morse M, McCauley MJ, Kitzrow JP, Musier-Forsyth K, Gorelick RJ, Rouzina I, Williams MC. HIV-1 Nucleocapsid Protein Binds Double-Stranded DNA in Multiple Modes to Regulate Compaction and Capsid Uncoating. Viruses 2022; 14:235. [PMID: 35215829 PMCID: PMC8879225 DOI: 10.3390/v14020235] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/07/2023] Open
Abstract
The HIV-1 nucleocapsid protein (NC) is a multi-functional protein necessary for viral replication. Recent studies have demonstrated reverse transcription occurs inside the fully intact viral capsid and that the timing of reverse transcription and uncoating are correlated. How a nearly 10 kbp viral DNA genome is stably contained within a narrow capsid with diameter similar to the persistence length of double-stranded (ds) DNA, and the role of NC in this process, are not well understood. In this study, we use optical tweezers, fluorescence imaging, and atomic force microscopy to observe NC binding a single long DNA substrate in multiple modes. We find that NC binds and saturates the DNA substrate in a non-specific binding mode that triggers uniform DNA self-attraction, condensing the DNA into a tight globule at a constant force up to 10 pN. When NC is removed from solution, the globule dissipates over time, but specifically-bound NC maintains long-range DNA looping that is less compact but highly stable. Both binding modes are additionally observed using AFM imaging. These results suggest multiple binding modes of NC compact DNA into a conformation compatible with reverse transcription, regulating the genomic pressure on the capsid and preventing premature uncoating.
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Affiliation(s)
- Helena Gien
- Department of Physics, Northeastern University, Boston, MA 02115, USA; (H.G.); (M.M.); (M.J.M.)
| | - Michael Morse
- Department of Physics, Northeastern University, Boston, MA 02115, USA; (H.G.); (M.M.); (M.J.M.)
| | - Micah J. McCauley
- Department of Physics, Northeastern University, Boston, MA 02115, USA; (H.G.); (M.M.); (M.J.M.)
| | - Jonathan P. Kitzrow
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA; (J.P.K.); (K.M.-F.); (I.R.)
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA; (J.P.K.); (K.M.-F.); (I.R.)
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA;
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, Ohio State University, Columbus, OH 43210, USA; (J.P.K.); (K.M.-F.); (I.R.)
| | - Mark C. Williams
- Department of Physics, Northeastern University, Boston, MA 02115, USA; (H.G.); (M.M.); (M.J.M.)
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6
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Lyonnais S, Sadiq SK, Lorca-Oró C, Dufau L, Nieto-Marquez S, Escribà T, Gabrielli N, Tan X, Ouizougun-Oubari M, Okoronkwo J, Reboud-Ravaux M, Gatell JM, Marquet R, Paillart JC, Meyerhans A, Tisné C, Gorelick RJ, Mirambeau G. The HIV-1 Nucleocapsid Regulates Its Own Condensation by Phase-Separated Activity-Enhancing Sequestration of the Viral Protease during Maturation. Viruses 2021; 13:v13112312. [PMID: 34835118 PMCID: PMC8625067 DOI: 10.3390/v13112312] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/09/2021] [Accepted: 11/11/2021] [Indexed: 02/07/2023] Open
Abstract
A growing number of studies indicate that mRNAs and long ncRNAs can affect protein populations by assembling dynamic ribonucleoprotein (RNP) granules. These phase-separated molecular ‘sponges’, stabilized by quinary (transient and weak) interactions, control proteins involved in numerous biological functions. Retroviruses such as HIV-1 form by self-assembly when their genomic RNA (gRNA) traps Gag and GagPol polyprotein precursors. Infectivity requires extracellular budding of the particle followed by maturation, an ordered processing of ∼2400 Gag and ∼120 GagPol by the viral protease (PR). This leads to a condensed gRNA-NCp7 nucleocapsid and a CAp24-self-assembled capsid surrounding the RNP. The choreography by which all of these components dynamically interact during virus maturation is one of the missing milestones to fully depict the HIV life cycle. Here, we describe how HIV-1 has evolved a dynamic RNP granule with successive weak–strong–moderate quinary NC-gRNA networks during the sequential processing of the GagNC domain. We also reveal two palindromic RNA-binding triads on NC, KxxFxxQ and QxxFxxK, that provide quinary NC-gRNA interactions. Consequently, the nucleocapsid complex appears properly aggregated for capsid reassembly and reverse transcription, mandatory processes for viral infectivity. We show that PR is sequestered within this RNP and drives its maturation/condensation within minutes, this process being most effective at the end of budding. We anticipate such findings will stimulate further investigations of quinary interactions and emergent mechanisms in crowded environments throughout the wide and growing array of RNP granules.
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Affiliation(s)
- Sébastien Lyonnais
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
- Centre d’Etudes des Maladies Infectieuses et Pharmacologie Anti-Infectieuse (CEMIPAI), CNRS UAR 3725, Université de Montpellier, 1919 Route de Mende, CEDEX 05, 34293 Montpellier, France
- Correspondence: (S.L.); (S.K.S.); (G.M.)
| | - S. Kashif Sadiq
- Infection Biology Laboratory, Department of Experimental and Health Sciences (DCEXS), Universitat Pompeu Fabra, Carrer Doctor Aiguader 88, 08003 Barcelona, Spain;
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
- Genome Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
- Correspondence: (S.L.); (S.K.S.); (G.M.)
| | - Cristina Lorca-Oró
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
| | - Laure Dufau
- Biological Adaptation and Ageing (B2A), CNRS UMR 8256 & INSERM ERL U1164, Institut de Biologie Paris-Seine (IBPS), Faculté des Sciences et d’Ingénierie (FSI), Sorbonne Université, 7 Quai St Bernard, CEDEX 05, 75252 Paris, France; (L.D.); (M.R.-R.)
| | - Sara Nieto-Marquez
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
| | - Tuixent Escribà
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
| | - Natalia Gabrielli
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
| | - Xiao Tan
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
- Biological Adaptation and Ageing (B2A), CNRS UMR 8256 & INSERM ERL U1164, Institut de Biologie Paris-Seine (IBPS), Faculté des Sciences et d’Ingénierie (FSI), Sorbonne Université, 7 Quai St Bernard, CEDEX 05, 75252 Paris, France; (L.D.); (M.R.-R.)
| | - Mohamed Ouizougun-Oubari
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
| | - Josephine Okoronkwo
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
| | - Michèle Reboud-Ravaux
- Biological Adaptation and Ageing (B2A), CNRS UMR 8256 & INSERM ERL U1164, Institut de Biologie Paris-Seine (IBPS), Faculté des Sciences et d’Ingénierie (FSI), Sorbonne Université, 7 Quai St Bernard, CEDEX 05, 75252 Paris, France; (L.D.); (M.R.-R.)
| | - José Maria Gatell
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
- Facultat de Medicina y Ciencias de la Salud, Universitat de Barcelona, Carrer de Casanova 143, 08036 Barcelona, Spain
| | - Roland Marquet
- Architecture et Réactivité de l’ARN, CNRS UPR 9002, Université de Strasbourg, 2 Allée Conrad Roentgen, 67000 Strasbourg, France; (R.M.); (J.-C.P.)
| | - Jean-Christophe Paillart
- Architecture et Réactivité de l’ARN, CNRS UPR 9002, Université de Strasbourg, 2 Allée Conrad Roentgen, 67000 Strasbourg, France; (R.M.); (J.-C.P.)
| | - Andreas Meyerhans
- Infection Biology Laboratory, Department of Experimental and Health Sciences (DCEXS), Universitat Pompeu Fabra, Carrer Doctor Aiguader 88, 08003 Barcelona, Spain;
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig de Lluís Companys 23, 08010 Barcelona, Spain
| | - Carine Tisné
- Expression Génétique Microbienne, CNRS UMR 8261, Institut de Biologie Physico-Chimique (IBPC), Université de Paris, 13 Rue Pierre et Marie Curie, 75005 Paris, France;
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA;
| | - Gilles Mirambeau
- Infectious Disease & AIDS Research Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villaroel 170, 08036 Barcelona, Spain; (C.L.-O.); (S.N.-M.); (T.E.); (N.G.); (X.T.); (M.O.-O.); (J.O.); (J.M.G.)
- Biologie Intégrative des Organismes Marins (BIOM), CNRS UMR 7232, Observatoire Océanologique de Banyuls (OOB), Faculté des Sciences et d’Ingénierie (FSI), Sorbonne Université, 1 Avenue Pierre Fabre, 66650 Banyuls-sur-Mer, France
- Correspondence: (S.L.); (S.K.S.); (G.M.)
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7
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Sheng Y, Cao B, Ou M, Wang Y, Yuan S, Zhang N, Zou T, Liu Y. Nucleocapsid protein preferentially binds the stem-loop of duplex/quadruplex hybrid that unfolds the quadruplex structure. Chem Commun (Camb) 2021; 57:5298-5301. [PMID: 33942834 DOI: 10.1039/d1cc01767e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
NCp7 protein binds the duplex/quadruplex hybrid structure, which decreases the thermal stability of DNA and unfolds the G-quadruplex structure. Interestingly, the duplex in the stem-loop region is the more favorable binding site of NCp7. The NCp7 binding twists the top G-tetrad, weakens hydrogen bonding and causes K+ ejection, hence disrupting the G4 structure.
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Affiliation(s)
- Yaping Sheng
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Bei Cao
- Warshel Institute for Computational Biology and General Education Division, The Chinese University of Hong Kong, Shenzhen, 518172, P. R. China
| | - Mingxi Ou
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Yu Wang
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Siming Yuan
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
| | - Na Zhang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, China
| | - Taotao Zou
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, 510006, P. R. China.
| | - Yangzhong Liu
- Department of Pharmacy, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230001, China.
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8
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Inhibitory Effect of Lithospermic Acid on the HIV-1 Nucleocapsid Protein. Molecules 2020; 25:molecules25225434. [PMID: 33233563 PMCID: PMC7699738 DOI: 10.3390/molecules25225434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/10/2020] [Accepted: 11/18/2020] [Indexed: 02/06/2023] Open
Abstract
The HIV-1 nucleocapsid protein (NC) is a desirable target in antiretroviral therapy due to its high conservation among HIV-1 strains, and to its multiple and crucial roles in the HIV-1 replication cycle. Natural products represent a valuable source of NC inhibitors, with the catechol group being a privileged scaffold in NC inhibition. By coupling molecular modeling with NMR spectroscopy and fluorescence-based assays, we disclosed lithospermic acid, a catechol derivative extracted from Salvia miltiorrhizza, as a potent and chemically stable non-covalent inhibitor of the NC. Being different from other catechol derivative reported so far, lithospermic acid does not undergo spontaneous oxidation in physiological conditions, thus becoming a profitable starting point for the development of efficient NC inhibitors.
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Nucleocapsid Protein Precursors NCp9 and NCp15 Suppress ATP-Mediated Rescue of AZT-Terminated Primers by HIV-1 Reverse Transcriptase. Antimicrob Agents Chemother 2020; 64:AAC.00958-20. [PMID: 32747359 DOI: 10.1128/aac.00958-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 07/29/2020] [Indexed: 01/20/2023] Open
Abstract
In HIV-1, development of resistance to AZT (3'-azido-3'-deoxythymidine) is mediated by the acquisition of thymidine analogue resistance mutations (TAMs) (i.e., M41L, D67N, K70R, L210W, T215F/Y, and K219E/Q) in the viral reverse transcriptase (RT). Clinically relevant combinations of TAMs, such as M41L/T215Y or D67N/K70R/T215F/K219Q, enhance the ATP-mediated excision of AZT monophosphate (AZTMP) from the 3' end of the primer, allowing DNA synthesis to continue. Additionally, during HIV-1 maturation, the Gag polyprotein is cleaved to release a mature nucleocapsid protein (NCp7) and two intermediate precursors (NCp9 and NCp15). NC proteins interact with the viral genome and facilitate the reverse transcription process. Using wild-type and TAM-containing RTs, we showed that both NCp9 and NCp15 inhibited ATP-mediated rescue of AZTMP-terminated primers annealed to RNA templates but not DNA templates, while NCp7 had no effect on rescue activity. RNase H inactivation by introducing the active-site mutation E478Q led to the loss of the inhibitory effect shown by NCp9. NCp15 had a stimulatory effect on the RT's RNase H activity not observed with NCp7 and NCp9. However, analysis of RNase H cleavage patterns revealed that in the presence of NCp9, RNA/DNA complexes containing duplexes of 12 bp had reduced stability in comparison with those obtained in the absence of NC or with NCp7 or NCp15. These effects are expected to have a strong influence on the inhibitory action of NCp9 and NCp15 by affecting the efficiency of RNA-dependent DNA polymerization after unblocking DNA primers terminated with AZTMP and other nucleotide analogues.
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10
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Influence of the amino-terminal sequence on the structure and function of HIV integrase. Retrovirology 2020; 17:28. [PMID: 32867805 PMCID: PMC7457537 DOI: 10.1186/s12977-020-00537-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 08/21/2020] [Indexed: 12/12/2022] Open
Abstract
Background Antiretroviral therapy (ART) can mitigate the morbidity and mortality caused by the human immunodeficiency virus (HIV). Successful development of ART can be accelerated by accurate structural and biochemical data on targets and their responses to inhibitors. One important ART target, HIV integrase (IN), has historically been studied in vitro in a modified form adapted to bacterial overexpression, with a methionine or a longer fusion protein sequence at the N-terminus. In contrast, IN present in viral particles is produced by proteolytic cleavage of the Pol polyprotein, which leaves a phenylalanine at the N-terminus (IN 1F). Inspection of available structures suggested that added residues on the N-terminus might disrupt proper protein folding and formation of multimeric complexes. Results We purified HIV-1 IN 1F1–212 and solved its structure at 2.4 Å resolution, which showed extension of an N-terminal helix compared to the published structure of IN1–212. Full-length IN 1F showed increased in vitro catalytic activity in assays of coupled joining of the two viral DNA ends compared to two IN variants containing additional N-terminal residues. IN 1F was also altered in its sensitivity to inhibitors, showing decreased sensitivity to the strand-transfer inhibitor raltegravir and increased sensitivity to allosteric integrase inhibitors. In solution, IN 1F exists as monomers and dimers, in contrast to other IN preparations which exist as higher-order oligomers. Conclusions The structural, biochemical, and biophysical characterization of IN 1F reveals the conformation of the native HIV-1 IN N-terminus and accompanying unique biochemical and biophysical properties. IN 1F thus represents an improved reagent for use in integration reactions in vitro and the development of antiretroviral agents.
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11
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Thermostable properties of the equine infectious anemia virus nucleocapsid protein NCp11. Biochem Biophys Res Commun 2019; 510:472-478. [DOI: 10.1016/j.bbrc.2019.01.137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 01/31/2019] [Indexed: 11/20/2022]
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12
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Shvadchak V, Zgheib S, Basta B, Humbert N, Langedijk J, Morris MC, Ciaco S, Maskri O, Darlix JL, Mauffret O, Fossé P, Réal E, Mély Y. Rationally Designed Peptides as Efficient Inhibitors of Nucleic Acid Chaperone Activity of HIV-1 Nucleocapsid Protein. Biochemistry 2018; 57:4562-4573. [PMID: 30019894 DOI: 10.1021/acs.biochem.8b00527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Due to its essential roles in the viral replication cycle and to its highly conserved sequence, the nucleocapsid protein (NCp7) of the human immunodeficiency virus type 1 is a target of choice for inhibiting replication of the virus. Most NCp7 inhibitors identified so far are small molecules. A small number of short peptides also act as NCp7 inhibitors by competing with its nucleic acid (NA) binding and chaperone activities but exhibit antiviral activity only at relatively high concentrations. In this work, in order to obtain more potent NCp7 competitors, we designed a library of longer peptides (10-17 amino acids) whose sequences include most of the NCp7 structural determinants responsible for its specific NA binding and destabilizing activities. Using an in vitro assay, the most active peptide (pE) was found to inhibit the NCp7 destabilizing activity, with a 50% inhibitory concentration in the nanomolar range, by competing with NCp7 for binding to its NA substrates. Formulated with a cell-penetrating peptide (CPP), pE was found to accumulate into HeLa cells, with low cytotoxicity. However, either formulated with a CPP or overexpressed in cells, pE did not show any antiviral activity. In vitro competition experiments revealed that its poor antiviral activity may be partly due to its sequestration by cellular RNAs. The selected peptide pE therefore appears to be a useful tool for investigating NCp7 properties and functions in vitro, but further work will be needed to design pE-derived peptides with antiviral activity.
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Affiliation(s)
- Volodymyr Shvadchak
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS , Université de Strasbourg , 74 route du Rhin , 67401 Illkirch , France
| | - Sarwat Zgheib
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS , Université de Strasbourg , 74 route du Rhin , 67401 Illkirch , France
| | - Beata Basta
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS , Université de Strasbourg , 74 route du Rhin , 67401 Illkirch , France
| | - Nicolas Humbert
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS , Université de Strasbourg , 74 route du Rhin , 67401 Illkirch , France
| | | | - May C Morris
- Institut des biomolécules Max Mousseron, CNRS, UMR 5247 , Université de Montpellier Faculté de Pharmacie , 15 av Charles Flahault 34093 Montpellier , France
| | - Stefano Ciaco
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS , Université de Strasbourg , 74 route du Rhin , 67401 Illkirch , France
| | - Ouerdia Maskri
- LBPA, ENS Paris Saclay, CNRS , Université Paris-Saclay , 94235 , Cachan Cedex , France
| | - Jean-Luc Darlix
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS , Université de Strasbourg , 74 route du Rhin , 67401 Illkirch , France
| | - Olivier Mauffret
- LBPA, ENS Paris Saclay, CNRS , Université Paris-Saclay , 94235 , Cachan Cedex , France
| | - Philippe Fossé
- LBPA, ENS Paris Saclay, CNRS , Université Paris-Saclay , 94235 , Cachan Cedex , France
| | - Eléonore Réal
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS , Université de Strasbourg , 74 route du Rhin , 67401 Illkirch , France
| | - Yves Mély
- Laboratory of Bioimaging and Pathologies, UMR 7021 CNRS , Université de Strasbourg , 74 route du Rhin , 67401 Illkirch , France
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13
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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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14
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Todd GC, Duchon A, Inlora J, Olson ED, Musier-Forsyth K, Ono A. Inhibition of HIV-1 Gag-membrane interactions by specific RNAs. RNA (NEW YORK, N.Y.) 2017; 23:395-405. [PMID: 27932583 PMCID: PMC5311501 DOI: 10.1261/rna.058453.116] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 12/07/2016] [Indexed: 05/03/2023]
Abstract
HIV-1 particle assembly, which occurs at the plasma membrane (PM) of cells, is driven by the viral polyprotein Gag. Gag recognizes phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2], a PM-specific phospholipid, via the highly basic region (HBR) in its N-terminal matrix (MA) domain. The HBR is also known to bind to RNA. We have previously shown, using an in vitro liposome binding assay, that RNA inhibits Gag binding to membranes that lack PI(4,5)P2 If this RNA block is removed by RNase treatment, Gag can bind nonspecifically to other negatively charged membranes. In an effort to identify the RNA species that confer this inhibition of Gag membrane binding, we have tested the impact of purified RNAs on Gag interactions with negatively charged liposomes lacking PI(4,5)P2 We found that some tRNA species and RNAs containing stem-loop 1 of the psi region in the 5' untranslated region of the HIV-1 genome impose inhibition of Gag binding to membranes lacking PI(4,5)P2 In contrast, a specific subset of tRNAs, as well as an RNA sequence previously selected in vitro for MA binding, failed to suppress Gag-membrane interactions. Furthermore, switching the identity of charged residues in the HBR did not diminish the susceptibility of Gag-liposome binding for each of the RNAs tested, while deletion of most of the NC domain abrogates the inhibition of membrane binding mediated by the RNAs that are inhibitory to WT Gag-liposome binding. These results support a model in which NC facilitates binding of RNA to MA and thereby promotes RNA-based inhibition of Gag-membrane binding.
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MESH Headings
- Aptamers, Nucleotide/chemical synthesis
- Aptamers, Nucleotide/pharmacology
- Base Pairing
- Base Sequence
- Binding Sites
- Cell Membrane/chemistry
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Cloning, Molecular
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- HIV-1/chemistry
- Humans
- Liposomes/antagonists & inhibitors
- Liposomes/chemistry
- Nucleic Acid Conformation
- Phosphatidylinositol 4,5-Diphosphate/chemistry
- Phosphatidylinositol 4,5-Diphosphate/deficiency
- Protein Binding/drug effects
- RNA, Transfer/chemistry
- RNA, Transfer/pharmacology
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Saccharomyces cerevisiae/chemistry
- Static Electricity
- gag Gene Products, Human Immunodeficiency Virus/antagonists & inhibitors
- gag Gene Products, Human Immunodeficiency Virus/chemistry
- gag Gene Products, Human Immunodeficiency Virus/genetics
- gag Gene Products, Human Immunodeficiency Virus/metabolism
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Affiliation(s)
- Gabrielle C Todd
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Alice Duchon
- Department of Chemistry and Biochemistry, Center for RNA Biology, and Center for Retrovirus Research, The Ohio State University, Columbus, Ohio 43210, USA
| | - Jingga Inlora
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Erik D Olson
- Department of Chemistry and Biochemistry, Center for RNA Biology, and Center for Retrovirus Research, The Ohio State University, Columbus, Ohio 43210, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for RNA Biology, and Center for Retrovirus Research, The Ohio State University, Columbus, Ohio 43210, USA
| | - Akira Ono
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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15
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Post K, Olson ED, Naufer MN, Gorelick RJ, Rouzina I, Williams MC, Musier-Forsyth K, Levin JG. Mechanistic differences between HIV-1 and SIV nucleocapsid proteins and cross-species HIV-1 genomic RNA recognition. Retrovirology 2016; 13:89. [PMID: 28034301 PMCID: PMC5198506 DOI: 10.1186/s12977-016-0322-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/29/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The nucleocapsid (NC) domain of HIV-1 Gag is responsible for specific recognition and packaging of genomic RNA (gRNA) into new viral particles. This occurs through specific interactions between the Gag NC domain and the Psi packaging signal in gRNA. In addition to this critical function, NC proteins are also nucleic acid (NA) chaperone proteins that facilitate NA rearrangements during reverse transcription. Although the interaction with Psi and chaperone activity of HIV-1 NC have been well characterized in vitro, little is known about simian immunodeficiency virus (SIV) NC. Non-human primates are frequently used as a platform to study retroviral infection in vivo; thus, it is important to understand underlying mechanistic differences between HIV-1 and SIV NC. RESULTS Here, we characterize SIV NC chaperone activity for the first time. Only modest differences are observed in the ability of SIV NC to facilitate reactions that mimic the minus-strand annealing and transfer steps of reverse transcription relative to HIV-1 NC, with the latter displaying slightly higher strand transfer and annealing rates. Quantitative single molecule DNA stretching studies and dynamic light scattering experiments reveal that these differences are due to significantly increased DNA compaction energy and higher aggregation capability of HIV-1 NC relative to the SIV protein. Using salt-titration binding assays, we find that both proteins are strikingly similar in their ability to specifically interact with HIV-1 Psi RNA. In contrast, they do not demonstrate specific binding to an RNA derived from the putative SIV packaging signal. CONCLUSIONS Based on these studies, we conclude that (1) HIV-1 NC is a slightly more efficient NA chaperone protein than SIV NC, (2) mechanistic differences between the NA interactions of highly similar retroviral NC proteins are revealed by quantitative single molecule DNA stretching, and (3) SIV NC demonstrates cross-species recognition of the HIV-1 Psi RNA packaging signal.
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Affiliation(s)
- Klara Post
- Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780 USA
| | - Erik D. Olson
- Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus, OH 43210 USA
| | - M. Nabuan Naufer
- Department of Physics, Northeastern University, Boston, MA 02115 USA
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702-1201 USA
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus, OH 43210 USA
| | - Mark C. Williams
- Department of Physics, Northeastern University, Boston, MA 02115 USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus, OH 43210 USA
| | - Judith G. Levin
- Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780 USA
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16
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Histones Are Rapidly Loaded onto Unintegrated Retroviral DNAs Soon after Nuclear Entry. Cell Host Microbe 2016; 20:798-809. [PMID: 27866901 DOI: 10.1016/j.chom.2016.10.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/25/2016] [Accepted: 10/11/2016] [Indexed: 12/30/2022]
Abstract
Chromosomal structure of nuclear DNA is usually maintained by insertion of nucleosomes into preexisting chromatin, both on newly synthesized DNA at replication forks and at sites of DNA damage. But during retrovirus infection, a histone-free DNA copy of the viral genome is synthesized that must be loaded with nucleosomes de novo. Here, we show that core histones are rapidly loaded onto unintegrated Moloney murine leukemia virus DNAs. Loading of nucleosomes requires nuclear entry, but does not require viral DNA integration. The histones associated with unintegrated DNAs become marked by covalent modifications, with a delay relative to the time of core histone loading. Expression from unintegrated DNA can be enhanced by modulation of the histone-modifying machinery. The data show that histone loading onto unintegrated DNAs occurs very rapidly after nuclear entry and does not require prior establishment of an integrated provirus.
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17
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Abstract
The HIV genome encodes a small number of viral proteins (i.e., 16), invariably establishing cooperative associations among HIV proteins and between HIV and host proteins, to invade host cells and hijack their internal machineries. As a known example, the HIV envelope glycoprotein GP120 is closely associated with GP41 for viral entry. From a genome-wide perspective, a hypothesis can be worked out to determine whether 16 HIV proteins could develop 120 possible pairwise associations either by physical interactions or by functional associations mediated via HIV or host molecules. Here, we present the first systematic review of experimental evidence on HIV genome-wide protein associations using a large body of publications accumulated over the past 3 decades. Of 120 possible pairwise associations between 16 HIV proteins, at least 34 physical interactions and 17 functional associations have been identified. To achieve efficient viral replication and infection, HIV protein associations play essential roles (e.g., cleavage, inhibition, and activation) during the HIV life cycle. In either a dispensable or an indispensable manner, each HIV protein collaborates with another viral protein to accomplish specific activities that precisely take place at the proper stages of the HIV life cycle. In addition, HIV genome-wide protein associations have an impact on anti-HIV inhibitors due to the extensive cross talk between drug-inhibited proteins and other HIV proteins. Overall, this study presents for the first time a comprehensive overview of HIV genome-wide protein associations, highlighting meticulous collaborations between all viral proteins during the HIV life cycle.
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Affiliation(s)
- Guangdi Li
- Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China KU Leuven-University of Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Leuven, Belgium
| | - Erik De Clercq
- KU Leuven-University of Leuven, Rega Institute for Medical Research, Department of Microbiology and Immunology, Leuven, Belgium
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18
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HIV Genome-Wide Protein Associations: a Review of 30 Years of Research. Microbiol Mol Biol Rev 2016; 80:679-731. [PMID: 27357278 DOI: 10.1128/mmbr.00065-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The HIV genome encodes a small number of viral proteins (i.e., 16), invariably establishing cooperative associations among HIV proteins and between HIV and host proteins, to invade host cells and hijack their internal machineries. As a known example, the HIV envelope glycoprotein GP120 is closely associated with GP41 for viral entry. From a genome-wide perspective, a hypothesis can be worked out to determine whether 16 HIV proteins could develop 120 possible pairwise associations either by physical interactions or by functional associations mediated via HIV or host molecules. Here, we present the first systematic review of experimental evidence on HIV genome-wide protein associations using a large body of publications accumulated over the past 3 decades. Of 120 possible pairwise associations between 16 HIV proteins, at least 34 physical interactions and 17 functional associations have been identified. To achieve efficient viral replication and infection, HIV protein associations play essential roles (e.g., cleavage, inhibition, and activation) during the HIV life cycle. In either a dispensable or an indispensable manner, each HIV protein collaborates with another viral protein to accomplish specific activities that precisely take place at the proper stages of the HIV life cycle. In addition, HIV genome-wide protein associations have an impact on anti-HIV inhibitors due to the extensive cross talk between drug-inhibited proteins and other HIV proteins. Overall, this study presents for the first time a comprehensive overview of HIV genome-wide protein associations, highlighting meticulous collaborations between all viral proteins during the HIV life cycle.
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19
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Yu KL, Lee SH, Lee ES, You JC. HIV-1 nucleocapsid protein localizes efficiently to the nucleus and nucleolus. Virology 2016; 492:204-12. [PMID: 26967976 DOI: 10.1016/j.virol.2016.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 10/22/2022]
Abstract
The HIV-1 nucleocapsid (NC) is an essential viral protein containing two highly conserved retroviral-type zinc finger (ZF) motifs, which functions in multiple stages of the HIV-1 life cycle. Although a number of functions for NC either in its mature form or as a domain of Gag have been revealed, little is known about the intracellular localization of NC and, moreover, its role in Gag protein trafficking. Here, we have investigated various forms of HIV-1 NC protein for its cellular localization and found that the NC has a strong nuclear and nucleolar localization activity. The linker region, composed of a stretch of basic amino acids between the two ZF motifs, was necessary and sufficient for the activity.
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Affiliation(s)
- Kyung Lee Yu
- National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seocho-gu Banpo-dong 505, Seoul 137-701, Republic of Korea
| | - Sun Hee Lee
- National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seocho-gu Banpo-dong 505, Seoul 137-701, Republic of Korea
| | - Eun Soo Lee
- National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seocho-gu Banpo-dong 505, Seoul 137-701, Republic of Korea
| | - Ji Chang You
- National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seocho-gu Banpo-dong 505, Seoul 137-701, Republic of Korea.
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20
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Fontana J, Jurado KA, Cheng N, Ly NL, Fuchs JR, Gorelick RJ, Engelman AN, Steven AC. Distribution and Redistribution of HIV-1 Nucleocapsid Protein in Immature, Mature, and Integrase-Inhibited Virions: a Role for Integrase in Maturation. J Virol 2015; 89:9765-80. [PMID: 26178982 PMCID: PMC4577894 DOI: 10.1128/jvi.01522-15] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 07/09/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED During virion maturation, HIV-1 capsid protein assembles into a conical core containing the viral ribonucleoprotein (vRNP) complex, thought to be composed mainly of the viral RNA and nucleocapsid protein (NC). After infection, the viral RNA is reverse transcribed into double-stranded DNA, which is then incorporated into host chromosomes by integrase (IN) catalysis. Certain IN mutations (class II) and antiviral drugs (allosteric IN inhibitors [ALLINIs]) adversely affect maturation, resulting in virions that contain "eccentric condensates," electron-dense aggregates located outside seemingly empty capsids. Here we demonstrate that in addition to this mislocalization of electron density, a class II IN mutation and ALLINIs each increase the fraction of virions with malformed capsids (from ∼ 12% to ∼ 53%). Eccentric condensates have a high NC content, as demonstrated by "tomo-bubblegram" imaging, a novel labeling technique that exploits the susceptibility of NC to radiation damage. Tomo-bubblegrams also localized NC inside wild-type cores and lining the spherical Gag shell in immature virions. We conclude that eccentric condensates represent nonpackaged vRNPs and that either genetic or pharmacological inhibition of IN can impair vRNP incorporation into mature cores. Supplying IN in trans as part of a Vpr-IN fusion protein partially restored the formation of conical cores with internal electron density and the infectivity of a class II IN deletion mutant virus. Moreover, the ability of ALLINIs to induce eccentric condensate formation required both IN and viral RNA. Based on these observations, we propose a role for IN in initiating core morphogenesis and vRNP incorporation into the mature core during HIV-1 maturation. IMPORTANCE Maturation, a process essential for HIV-1 infectivity, involves core assembly, whereby the viral ribonucleoprotein (vRNP, composed of vRNA and nucleocapsid protein [NC]) is packaged into a conical capsid. Allosteric integrase inhibitors (ALLINIs) affect multiple viral processes. We have characterized ALLINIs and integrase mutants that have the same phenotype. First, by comparing the effects of ALLINIs on several steps of the viral cycle, we show that inhibition of maturation accounts for compound potency. Second, by using cryoelectron tomography, we find that ALLINIs impair conical capsid assembly. Third, by developing tomo-bubblegram imaging, which specifically labels NC protein, we find that ALLINIs block vRNP packaging; instead, vRNPs form "eccentric condensates" outside the core. Fourth, malformed cores, typical of integrase-deleted virus, are partially replaced by conical cores when integrase is supplied in trans. Fifth, vRNA is necessary for ALLINI-induced eccentric condensate formation. These observations suggest that integrase is involved in capsid morphogenesis and vRNP packaging.
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Affiliation(s)
- Juan Fontana
- Laboratory of Structural Biology Research, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Kellie A Jurado
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Naiqian Cheng
- Laboratory of Structural Biology Research, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Ngoc L Ly
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - James R Fuchs
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio, USA
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Alan N Engelman
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Alasdair C Steven
- Laboratory of Structural Biology Research, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland, USA
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21
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DNA Physical Properties and Nucleosome Positions Are Major Determinants of HIV-1 Integrase Selectivity. PLoS One 2015; 10:e0129427. [PMID: 26075397 PMCID: PMC4468133 DOI: 10.1371/journal.pone.0129427] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 05/09/2015] [Indexed: 02/06/2023] Open
Abstract
Retroviral integrases (INs) catalyse the integration of the reverse transcribed viral DNA into the host cell genome. This process is selective, and chromatin has been proposed to be a major factor regulating this step in the viral life cycle. However, the precise underlying mechanisms are still under investigation. We have developed a new in vitro integration assay using physiologically-relevant, reconstituted genomic acceptor chromatin and high-throughput determination of nucleosome positions and integration sites, in parallel. A quantitative analysis of the resulting data reveals a chromatin-dependent redistribution of the integration sites and establishes a link between integration sites and nucleosome positions. The co-activator LEDGF/p75 enhanced integration but did not modify the integration sites under these conditions. We also conducted an in cellulo genome-wide comparative study of nucleosome positions and human immunodeficiency virus type-1 (HIV-1) integration sites identified experimentally in vivo. These studies confirm a preferential integration in nucleosome-covered regions. Using a DNA mechanical energy model, we show that the physical properties of DNA probed by IN binding are important in determining IN selectivity. These novel in vitro and in vivo approaches confirm that IN has a preference for integration into a nucleosome, and suggest the existence of two levels of IN selectivity. The first depends on the physical properties of the target DNA and notably, the energy required to fit DNA into the IN catalytic pocket. The second depends on the DNA deformation associated with DNA wrapping around a nucleosome. Taken together, these results indicate that HIV-1 IN is a shape-readout DNA binding protein.
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Anton H, Taha N, Boutant E, Richert L, Khatter H, Klaholz B, Rondé P, Réal E, de Rocquigny H, Mély Y. Investigating the cellular distribution and interactions of HIV-1 nucleocapsid protein by quantitative fluorescence microscopy. PLoS One 2015; 10:e0116921. [PMID: 25723396 PMCID: PMC4344342 DOI: 10.1371/journal.pone.0116921] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 12/16/2014] [Indexed: 12/12/2022] Open
Abstract
The nucleocapsid protein (NCp7) of the Human immunodeficiency virus type 1 (HIV-1) is a small basic protein containing two zinc fingers. About 2000 NCp7 molecules coat the genomic RNA in the HIV-1 virion. After infection of a target cell, the viral core enters into the cytoplasm, where NCp7 chaperones the reverse transcription of the genomic RNA into the proviral DNA. As a consequence of their much lower affinity for double-stranded DNA as compared to single-stranded RNAs, NCp7 molecules are thought to be released in the cytoplasm and the nucleus of infected cells in the late steps of reverse transcription. Yet, little is known on the cellular distribution of the released NCp7 molecules and on their possible interactions with cell components. Hence, the aim of this study was to identify potential cellular partners of NCp7 and to monitor its intracellular distribution and dynamics by means of confocal fluorescence microscopy, fluorescence lifetime imaging microscopy, fluorescence recovery after photobleaching, fluorescence correlation and cross-correlation spectroscopy, and raster imaging correlation spectroscopy. HeLa cells transfected with eGFP-labeled NCp7 were used as a model system. We found that NCp7-eGFP localizes mainly in the cytoplasm and the nucleoli, where it binds to cellular RNAs, and notably to ribosomal RNAs which are the most abundant. The binding of NCp7 to ribosomes was further substantiated by the intracellular co-diffusion of NCp7 with the ribosomal protein 26, a component of the large ribosomal subunit. Finally, gradient centrifugation experiments demonstrate a direct association of NCp7 with purified 80S ribosomes. Thus, our data suggest that NCp7 molecules released in newly infected cells may primarily bind to ribosomes, where they may exert a new potential role in HIV-1 infection.
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Affiliation(s)
- Halina Anton
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
- * E-mail: (YM); (HA)
| | - Nedal Taha
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Emmanuel Boutant
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Ludovic Richert
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Heena Khatter
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104 CNRS, U964 Inserm, Université de Strasbourg, Illkirch, France
| | - Bruno Klaholz
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, UMR 7104 CNRS, U964 Inserm, Université de Strasbourg, Illkirch, France
| | - Philippe Rondé
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Eléonore Réal
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Hugues de Rocquigny
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
- * E-mail: (YM); (HA)
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Engelman A, Cherepanov P. Retroviral Integrase Structure and DNA Recombination Mechanism. Microbiol Spectr 2015; 2:1-22. [PMID: 25705574 PMCID: PMC4334468 DOI: 10.1128/microbiolspec.mdna3-0024-2014] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Indexed: 12/13/2022] Open
Abstract
Due to the importance of human immunodeficiency virus type 1 (HIV-1) integrase as a drug target, the biochemistry and structural aspects of retroviral DNA integration have been the focus of intensive research during the past three decades. The retroviral integrase enzyme acts on the linear double-stranded viral DNA product of reverse transcription. Integrase cleaves specific phosphodiester bonds near the viral DNA ends during the 3' processing reaction. The enzyme then uses the resulting viral DNA 3'-OH groups during strand transfer to cut chromosomal target DNA, which simultaneously joins both viral DNA ends to target DNA 5'-phosphates. Both reactions proceed via direct transesterification of scissile phosphodiester bonds by attacking nucleophiles: a water molecule for 3' processing, and the viral DNA 3'-OH for strand transfer. X-ray crystal structures of prototype foamy virus integrase-DNA complexes revealed the architectures of the key nucleoprotein complexes that form sequentially during the integration process and explained the roles of active site metal ions in catalysis. X-ray crystallography furthermore elucidated the mechanism of action of HIV-1 integrase strand transfer inhibitors, which are currently used to treat AIDS patients, and provided valuable insights into the mechanisms of viral drug resistance.
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Affiliation(s)
- Alan Engelman
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, 450 Brookline, Avenue, CLS-1010, Boston, MA 02215
| | - Peter Cherepanov
- Cancer Research UK London Research Institute, Clare Hall Laboratories, Blanche Lane, Potters Bar, EN6 3LD, United Kingdom
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Craigie R, Bushman FD. Host Factors in Retroviral Integration and the Selection of Integration Target Sites. Microbiol Spectr 2014; 2:10.1128/microbiolspec.MDNA3-0026-2014. [PMID: 26104434 PMCID: PMC4525071 DOI: 10.1128/microbiolspec.mdna3-0026-2014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Indexed: 02/07/2023] Open
Abstract
In order to replicate, a retrovirus must integrate a DNA copy of the viral RNA genome into a chromosome of the host cell. The study of retroviral integration has advanced considerably in the past few years. Here we focus on host factor interactions and the linked area of integration targeting. Genome-wide screens for cellular factors affecting HIV replication have identified a series of host cell proteins that may mediate subcellular trafficking for preintegration complexes, nuclear import, and integration target site selection. The cell transcriptional co-activator protein LEDGF/p75 has been identified as a tethering factor important for HIV integration, and recently, BET proteins (Brd2, 4, and 4) have been identified as tethering factors for the gammaretroviruses. A new class of HIV inhibitors has been developed targeting the HIV-1 IN-LEDGF binding site, though surprisingly these inhibitors appear to block assembly late during replication and do not act at the integration step. Going forward, genome-wide studies of HIV-host interactions offer many new starting points to investigate HIV replication and identify potential new inhibitor targets.
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Affiliation(s)
- Robert Craigie
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0560
| | - Frederic D. Bushman
- Department of Microbiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
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Wu T, Gorelick RJ, Levin JG. Selection of fully processed HIV-1 nucleocapsid protein is required for optimal nucleic acid chaperone activity in reverse transcription. Virus Res 2014; 193:52-64. [PMID: 24954787 PMCID: PMC4252486 DOI: 10.1016/j.virusres.2014.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/09/2014] [Accepted: 06/10/2014] [Indexed: 12/14/2022]
Abstract
The mature HIV-1 nucleocapsid protein (NCp7) is generated by sequential proteolytic cleavage of precursor proteins containing additional C-terminal peptides: NCp15 (NCp7-spacer peptide 2 (SP2)-p6); and NCp9 (NCp7-SP2). Here, we compare the nucleic acid chaperone activities of the three proteins, using reconstituted systems that model the annealing and elongation steps in tRNA(Lys3)-primed (-) strong-stop DNA synthesis and subsequent minus-strand transfer. The maximum levels of annealing are similar for all of the proteins, but there are important differences in their ability to facilitate reverse transcriptase (RT)-catalyzed DNA extension. Thus, at low concentrations, NCp9 has the greatest activity, but with increasing concentrations, DNA synthesis is significantly reduced. This finding reflects NCp9's strong nucleic acid binding affinity (associated with the highly basic SP2 domain) as well as its slow dissociation kinetics, which together limit the ability of RT to traverse the nucleic acid template. NCp15 has the poorest activity of the three proteins due to its acidic p6 domain. Indeed, mutants with alanine substitutions for the acidic residues in p6 have improved chaperone function. Collectively, these data can be correlated with the known biological properties of NCp9 and NCp15 mutant virions and help to explain why mature NC has evolved as the critical cofactor for efficient virus replication and long-term viral fitness.
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Affiliation(s)
- Tiyun Wu
- Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702-1201, USA
| | - Judith G Levin
- Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA.
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26
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The HIV-1 nucleocapsid protein recruits negatively charged lipids to ensure its optimal binding to lipid membranes. J Virol 2014; 89:1756-67. [PMID: 25410868 DOI: 10.1128/jvi.02931-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED The HIV-1 Gag polyprotein precursor composed of the matrix (MA), capsid (CA), nucleocapsid (NC), and p6 domains orchestrates virus assembly via interactions between MA and the cell plasma membrane (PM) on one hand and NC and the genomic RNA on the other hand. As the Gag precursor can adopt a bent conformation, a potential interaction of the NC domain with the PM cannot be excluded during Gag assembly at the PM. To investigate the possible interaction of NC with lipid membranes in the absence of any interference from the other domains of Gag, we quantitatively characterized by fluorescence spectroscopy the binding of the mature NC protein to large unilamellar vesicles (LUVs) used as membrane models. We found that NC, either in its free form or bound to an oligonucleotide, was binding with high affinity (∼ 10(7) M(-1)) to negatively charged LUVs. The number of NC binding sites, but not the binding constant, was observed to decrease with the percentage of negatively charged lipids in the LUV composition, suggesting that NC and NC/oligonucleotide complexes were able to recruit negatively charged lipids to ensure optimal binding. However, in contrast to MA, NC did not exhibit a preference for phosphatidylinositol-(4,5)-bisphosphate. These results lead us to propose a modified Gag assembly model where the NC domain contributes to the initial binding of the bent form of Gag to the PM. IMPORTANCE The NC protein is a highly conserved nucleic acid binding protein that plays numerous key roles in HIV-1 replication. While accumulating evidence shows that NC either as a mature protein or as a domain of the Gag precursor also interacts with host proteins, only a few data are available on the possible interaction of NC with lipid membranes. Interestingly, during HIV-1 assembly, the Gag precursor is thought to adopt a bent conformation where the NC domain may interact with the plasma membrane. In this context, we quantitatively characterized the binding of NC, as a free protein or as a complex with nucleic acids, to lipid membranes and showed that the latter constitute a binding platform for NC. Taken together, our data suggest that the NC domain may play a role in the initial binding events of Gag to the plasma membrane during HIV-1 assembly.
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Retrospective on the all-in-one retroviral nucleocapsid protein. Virus Res 2014; 193:2-15. [PMID: 24907482 PMCID: PMC7114435 DOI: 10.1016/j.virusres.2014.05.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 05/11/2014] [Accepted: 05/11/2014] [Indexed: 01/08/2023]
Abstract
This retrospective reviews 30 years of research on the retroviral nucleocapsid protein (NC) focusing on HIV-1 NC. Originally considered as a non-specific nucleic-acid binding protein, NC has seminal functions in virus replication. Indeed NC turns out to be a all-in-one viral protein that chaperones viral DNA synthesis and integration, and virus formation. As a chaperone NC provides assistance to genetic recombination thus allowing the virus to escape the immune response and antiretroviral therapies against HIV-1.
This review aims at briefly presenting a retrospect on the retroviral nucleocapsid protein (NC), from an unspecific nucleic acid binding protein (NABP) to an all-in-one viral protein with multiple key functions in the early and late phases of the retrovirus replication cycle, notably reverse transcription of the genomic RNA and viral DNA integration into the host genome, and selection of the genomic RNA together with the initial steps of virus morphogenesis. In this context we will discuss the notion that NC protein has a flexible conformation and is thus a member of the growing family of intrinsically disordered proteins (IDPs) where disorder may account, at least in part, for its function as a nucleic acid (NA) chaperone and possibly as a protein chaperone vis-à-vis the viral DNA polymerase during reverse transcription. Lastly, we will briefly review the development of new anti-retroviral/AIDS compounds targeting HIV-1 NC because it represents an ideal target due to its multiple roles in the early and late phases of virus replication and its high degree of conservation.
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28
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Bushman FD. Engineering the human genome: reflections on the beginning. Hum Gene Ther 2014; 25:395-400. [PMID: 24848314 DOI: 10.1089/hum.2014.2524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Frederic D Bushman
- Department of Microbiology, University of Pennsylvania School of Medicine , Philadelphia, PA 19104-6076
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Abstract
Reverse transcription is an obligatory step in retrovirus replication in the course of which the retroviral RNA/DNA-dependent DNA polymerase (RT) copies the single-stranded positive sense RNA genome to synthesize the double-stranded viral DNA. At the same time the RT-associated RNaseH activity degrades the genomic RNA template, which has just been copied. The viral nucleocapsid protein NCp7 is an obligatory partner of RT, chaperoning synthesis of the complete viral DNA flanked by the two long-terminal repeats (LTR), required for viral DNA integration into the host genome and its expression. Here we describe assays for in vitro and ex vivo monitoring of reverse transcription and the chaperoning role of the nucleocapsid protein (NC).
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Wang W, Naiyer N, Mitra M, Li J, Williams MC, Rouzina I, Gorelick RJ, Wu Z, Musier-Forsyth K. Distinct nucleic acid interaction properties of HIV-1 nucleocapsid protein precursor NCp15 explain reduced viral infectivity. Nucleic Acids Res 2014; 42:7145-59. [PMID: 24813443 PMCID: PMC4066767 DOI: 10.1093/nar/gku335] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
During human immunodeficiency virus type 1 (HIV-1) maturation, three different forms of nucleocapsid (NC) protein—NCp15 (p9 + p6), NCp9 (p7 + SP2) and NCp7—appear successively. A mutant virus expressing NCp15 shows greatly reduced infectivity. Mature NCp7 is a chaperone protein that facilitates remodeling of nucleic acids (NAs) during reverse transcription. To understand the strict requirement for NCp15 processing, we compared the chaperone function of the three forms of NC. NCp15 anneals tRNA to the primer-binding site at a similar rate as NCp7, whereas NCp9 is the most efficient annealing protein. Assays to measure NA destabilization show a similar trend. Dynamic light scattering studies reveal that NCp15 forms much smaller aggregates relative to those formed by NCp7 and NCp9. Nuclear magnetic resonance studies suggest that the acidic p6 domain of HIV-1 NCp15 folds back and interacts with the basic zinc fingers. Neutralizing the acidic residues in p6 improves the annealing and aggregation activity of NCp15 to the level of NCp9 and increases the protein–NA aggregate size. Slower NCp15 dissociation kinetics is observed by single-molecule DNA stretching, consistent with the formation of electrostatic inter-protein contacts, which likely contribute to the distinct aggregate morphology, irregular HIV-1 core formation and non-infectious virus.
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Affiliation(s)
- Wei Wang
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Nada Naiyer
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Mithun Mitra
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Jialin Li
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Mark C Williams
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Ioulia Rouzina
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Zhengrong Wu
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
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Sun M, Grigsby IF, Gorelick RJ, Mansky LM, Musier-Forsyth K. Retrovirus-specific differences in matrix and nucleocapsid protein-nucleic acid interactions: implications for genomic RNA packaging. J Virol 2014; 88:1271-80. [PMID: 24227839 PMCID: PMC3911680 DOI: 10.1128/jvi.02151-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/04/2013] [Indexed: 11/20/2022] Open
Abstract
Retroviral RNA encapsidation involves a recognition event between genomic RNA (gRNA) and one or more domains in Gag. In HIV-1, the nucleocapsid (NC) domain is involved in gRNA packaging and displays robust nucleic acid (NA) binding and chaperone functions. In comparison, NC of human T-cell leukemia virus type 1 (HTLV-1), a deltaretrovirus, displays weaker NA binding and chaperone activity. Mutation of conserved charged residues in the deltaretrovirus bovine leukemia virus (BLV) matrix (MA) and NC domains affects virus replication and gRNA packaging efficiency. Based on these observations, we hypothesized that the MA domain may generally contribute to NA binding and genome encapsidation in deltaretroviruses. Here, we examined the interaction between HTLV-2 and HIV-1 MA proteins and various NAs in vitro. HTLV-2 MA displays higher NA binding affinity and better chaperone activity than HIV-1 MA. HTLV-2 MA also binds NAs with higher affinity than HTLV-2 NC and displays more robust chaperone function. Mutation of two basic residues in HTLV-2 MA α-helix II, previously implicated in BLV gRNA packaging, reduces NA binding affinity. HTLV-2 MA binds with high affinity and specificity to RNA derived from the putative packaging signal of HTLV-2 relative to nonspecific NA. Furthermore, an HIV-1 MA triple mutant designed to mimic the basic character of HTLV-2 MA α-helix II dramatically improves binding affinity and chaperone activity of HIV-1 MA in vitro and restores RNA packaging to a ΔNC HIV-1 variant in cell-based assays. Taken together, these results are consistent with a role for deltaretrovirus MA proteins in viral RNA packaging.
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Affiliation(s)
- Meng Sun
- Department of Chemistry and Biochemistry, Center for Retroviral Research, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Iwen F. Grigsby
- Institute for Molecular Virology, Departments of Diagnostic and Biological Sciences and Microbiology, School of Dentistry and Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Louis M. Mansky
- Institute for Molecular Virology, Departments of Diagnostic and Biological Sciences and Microbiology, School of Dentistry and Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retroviral Research, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
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Wu H, Mitra M, Naufer MN, McCauley MJ, Gorelick RJ, Rouzina I, Musier-Forsyth K, Williams MC. Differential contribution of basic residues to HIV-1 nucleocapsid protein's nucleic acid chaperone function and retroviral replication. Nucleic Acids Res 2013; 42:2525-37. [PMID: 24293648 PMCID: PMC3936775 DOI: 10.1093/nar/gkt1227] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) protein contains 15 basic residues located throughout its 55-amino acid sequence, as well as one aromatic residue in each of its two CCHC-type zinc finger motifs. NC facilitates nucleic acid (NA) rearrangements via its chaperone activity, but the structural basis for this activity and its consequences in vivo are not completely understood. Here, we investigate the role played by basic residues in the N-terminal domain, the N-terminal zinc finger and the linker region between the two zinc fingers. We use in vitro ensemble and single-molecule DNA stretching experiments to measure the characteristics of wild-type and mutant HIV-1 NC proteins, and correlate these results with cell-based HIV-1 replication assays. All of the cationic residue mutations lead to NA interaction defects, as well as reduced HIV-1 infectivity, and these effects are most pronounced on neutralizing all five N-terminal cationic residues. HIV-1 infectivity in cells is correlated most strongly with NC’s NA annealing capabilities as well as its ability to intercalate the DNA duplex. Although NC’s aromatic residues participate directly in DNA intercalation, our findings suggest that specific basic residues enhance these interactions, resulting in optimal NA chaperone activity.
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Affiliation(s)
- Hao Wu
- Department of Physics, Northeastern University, Boston, MA 02115, USA, Department of Chemistry and Biochemistry, Center for RNA Biology, and Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA, AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA and Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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Wu H, Mitra M, McCauley MJ, Thomas JA, Rouzina I, Musier-Forsyth K, Williams MC, Gorelick RJ. Aromatic residue mutations reveal direct correlation between HIV-1 nucleocapsid protein's nucleic acid chaperone activity and retroviral replication. Virus Res 2013; 171:263-77. [PMID: 22814429 PMCID: PMC3745225 DOI: 10.1016/j.virusres.2012.07.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 07/02/2012] [Accepted: 07/07/2012] [Indexed: 10/28/2022]
Abstract
The human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) protein plays an essential role in several stages of HIV-1 replication. One important function of HIV-1 NC is to act as a nucleic acid chaperone, in which the protein facilitates nucleic acid rearrangements important for reverse transcription and recombination. NC contains only 55 amino acids, with 15 basic residues and two zinc fingers, each having a single aromatic residue (Phe16 and Trp37). Despite its simple structure, HIV-1 NC appears to have optimal chaperone activity, including the ability to strongly aggregate nucleic acids, destabilize nucleic acid secondary structure, and facilitate rapid nucleic acid annealing. Here we combine single molecule DNA stretching experiments with ensemble solution studies of protein-nucleic acid binding affinity, oligonucleotide annealing, and nucleic acid aggregation to measure the characteristics of wild-type (WT) and aromatic residue mutants of HIV-1 NC that are important for nucleic acid chaperone activity. These in vitro results are compared to in vivo HIV-1 replication for viruses containing the same mutations. This work allows us to directly relate HIV-1 NC structure with its function as a nucleic acid chaperone in vitro and in vivo. We show that replacement of either aromatic residue with another aromatic residue results in a protein that strongly resembles WT NC. In contrast, single amino acid substitutions of either Phe16Ala or Trp37Ala significantly slow down NC's DNA interaction kinetics, while retaining some helix-destabilization capability. A double Phe16Ala/Trp37Ala substitution further reduces the latter activity. Surprisingly, the ensemble nucleic acid binding, annealing, and aggregation properties are not significantly altered for any mutant except the double aromatic substitution with Ala. Thus, elimination of a single aromatic residue from either zinc finger strongly reduces NC's chaperone activity as determined by single molecule DNA stretching experiments without significantly altering its ensemble-averaged biochemical properties. Importantly, the substitution of aromatic residues with Ala progressively decreases NC's nucleic acid chaperone activity while also progressively inhibiting viral replication. Taken together, these data support the critical role of HIV-1 NC's aromatic residues, and establish a direct and statistically significant correlation between nucleic acid chaperone activity and viral replication.
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Affiliation(s)
- Hao Wu
- Northeastern University, Department of Physics, Boston, MA 02115, USA
| | - Mithun Mitra
- The Ohio State University, Department of Chemistry and Biochemistry, Center for Retrovirus Research, Center for RNA Biology, Columbus, OH 43210, USA
| | - Micah J. McCauley
- Northeastern University, Department of Physics, Boston, MA 02115, USA
| | - James A. Thomas
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Ioulia Rouzina
- University of Minnesota, Department of Biochemistry, Molecular Biology, and Biophysics, Minneapolis, MN 55455, USA
| | - Karin Musier-Forsyth
- The Ohio State University, Department of Chemistry and Biochemistry, Center for Retrovirus Research, Center for RNA Biology, Columbus, OH 43210, USA
| | - Mark C. Williams
- Northeastern University, Department of Physics, Boston, MA 02115, USA
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
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Hergott CB, Mitra M, Guo J, Wu T, Miller JT, Iwatani Y, Gorelick RJ, Levin JG. Zinc finger function of HIV-1 nucleocapsid protein is required for removal of 5'-terminal genomic RNA fragments: a paradigm for RNA removal reactions in HIV-1 reverse transcription. Virus Res 2013; 171:346-55. [PMID: 23149014 PMCID: PMC3578084 DOI: 10.1016/j.virusres.2012.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 07/27/2012] [Accepted: 08/20/2012] [Indexed: 11/28/2022]
Abstract
During (-) strong-stop DNA [(-) SSDNA] synthesis, RNase H cleavage of genomic viral RNA generates small 5'-terminal RNA fragments (14-18 nt) that remain annealed to the DNA. Unless these fragments are removed, the minus-strand transfer reaction, required for (-) SSDNA elongation, cannot occur. Here, we describe the mechanism of 5'-terminal RNA removal and the roles of HIV-1 nucleocapsid protein (NC) and RNase H cleavage in this process. Using an NC-dependent system that models minus-strand transfer, we show that the presence of short terminal fragments pre-annealed to (-) SSDNA has no impact on strand transfer, implying efficient fragment removal. Moreover, in reactions with an RNase H(-) reverse transcriptase mutant, NC alone is able to facilitate fragment removal, albeit less efficiently than in the presence of both RNase H activity and NC. Results obtained from novel electrophoretic gel mobility shift and Förster Resonance Energy Transfer assays, which each directly measure RNA fragment release from a duplex in the absence of DNA synthesis, demonstrate for the first time that the architectural integrity of NC's zinc finger (ZF) domains is absolutely required for this reaction. This suggests that NC's helix destabilizing activity (associated with the ZFs) facilitates strand exchange through the displacement of these short terminal RNAs by the longer 3' acceptor RNA, which forms a more stable duplex with (-) SSDNA. Taken together with previously published results, we conclude that NC-mediated fragment removal is linked mechanistically with selection of the correct primer for plus-strand DNA synthesis and tRNA removal step prior to plus-strand transfer. Thus, HIV-1 has evolved a single mechanism for these RNA removal reactions that are critical for successful reverse transcription.
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MESH Headings
- DNA, Viral/chemistry
- DNA, Viral/genetics
- DNA, Viral/metabolism
- Gene Expression Regulation, Viral
- HIV-1/chemistry
- HIV-1/genetics
- HIV-1/metabolism
- RNA Processing, Post-Transcriptional
- RNA, Viral/chemistry
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Reverse Transcription
- Zinc Fingers
- gag Gene Products, Human Immunodeficiency Virus/chemistry
- gag Gene Products, Human Immunodeficiency Virus/genetics
- gag Gene Products, Human Immunodeficiency Virus/metabolism
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Affiliation(s)
- Christopher B. Hergott
- Section on Viral Gene Regulation, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA
| | - Mithun Mitra
- Section on Viral Gene Regulation, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA
| | - Jianhui Guo
- Section on Viral Gene Regulation, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA
| | - Tiyun Wu
- Section on Viral Gene Regulation, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA
| | - Jennifer T. Miller
- Reverse Transcriptase Biochemistry Section, HIV Drug Resistance Program, National Cancer Institute, National Institutes of Health, Frederick National Laboratory for Cancer Research, Frederick, MD 21702-1201, USA
| | - Yasumasa Iwatani
- Section on Viral Gene Regulation, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702-1201, USA
| | - Judith G. Levin
- Section on Viral Gene Regulation, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA
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35
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Lyonnais S, Gorelick RJ, Heniche-Boukhalfa F, Bouaziz S, Parissi V, Mouscadet JF, Restle T, Gatell JM, Le Cam E, Mirambeau G. A protein ballet around the viral genome orchestrated by HIV-1 reverse transcriptase leads to an architectural switch: from nucleocapsid-condensed RNA to Vpr-bridged DNA. Virus Res 2013; 171:287-303. [PMID: 23017337 PMCID: PMC3552025 DOI: 10.1016/j.virusres.2012.09.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 09/13/2012] [Accepted: 09/14/2012] [Indexed: 12/15/2022]
Abstract
HIV-1 reverse transcription is achieved in the newly infected cell before viral DNA (vDNA) nuclear import. Reverse transcriptase (RT) has previously been shown to function as a molecular motor, dismantling the nucleocapsid complex that binds the viral genome as soon as plus-strand DNA synthesis initiates. We first propose a detailed model of this dismantling in close relationship with the sequential conversion from RNA to double-stranded (ds) DNA, focusing on the nucleocapsid protein (NCp7). The HIV-1 DNA-containing pre-integration complex (PIC) resulting from completion of reverse transcription is translocated through the nuclear pore. The PIC nucleoprotein architecture is poorly understood but contains at least two HIV-1 proteins initially from the virion core, namely integrase (IN) and the viral protein r (Vpr). We next present a set of electron micrographs supporting that Vpr behaves as a DNA architectural protein, initiating multiple DNA bridges over more than 500 base pairs (bp). These complexes are shown to interact with NCp7 bound to single-stranded nucleic acid regions that are thought to maintain IN binding during dsDNA synthesis, concurrently with nucleocapsid complex dismantling. This unexpected binding of Vpr conveniently leads to a compacted but filamentous folding of the vDNA that should favor its nuclear import. Finally, nucleocapsid-like aggregates engaged in dsDNA synthesis appear to efficiently bind to F-actin filaments, a property that may be involved in targeting complexes to the nuclear envelope. More generally, this article highlights unique possibilities offered by in vitro reconstitution approaches combined with macromolecular imaging to gain insights into the mechanisms that alter the nucleoprotein architecture of the HIV-1 genome, ultimately enabling its insertion into the nuclear chromatin.
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MESH Headings
- DNA Packaging
- DNA, Viral/chemistry
- DNA, Viral/genetics
- DNA, Viral/metabolism
- Genome, Viral
- HIV Integrase/genetics
- HIV Integrase/metabolism
- HIV Reverse Transcriptase/genetics
- HIV Reverse Transcriptase/metabolism
- HIV-1/chemistry
- HIV-1/enzymology
- HIV-1/genetics
- HIV-1/metabolism
- Humans
- RNA, Viral/chemistry
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Reverse Transcription
- gag Gene Products, Human Immunodeficiency Virus/genetics
- gag Gene Products, Human Immunodeficiency Virus/metabolism
- vpr Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program; SAIC-Frederick, Inc.; Frederick National Laboratory for Cancer Research; Frederick, MD USA
| | - Fatima Heniche-Boukhalfa
- Maintenance des génomes, Microscopies Moléculaire et Bionanosciences; UMR 8126 CNRS-Université Paris Sud, Villejuif, F-94805, France
| | - Serge Bouaziz
- Laboratoire de Cristallographie et RMN biologiques; UMR 8015 CNRS-Université Paris Descartes; Paris, F-75006, France
| | - Vincent Parissi
- Laboratoire de Microbiologie Fondamentale et Pathogénicité, UMR5234 CNRS-Université Bordeaux Segalen, France
| | | | - Tobias Restle
- Institute of Molecular Medicine, University of Lübeck, Center for Structural and Cell Biology in Medicine (CSCM), D-23538 Lübeck, Germany
| | | | - Eric Le Cam
- Maintenance des génomes, Microscopies Moléculaire et Bionanosciences; UMR 8126 CNRS-Université Paris Sud, Villejuif, F-94805, France
| | - Gilles Mirambeau
- AIDS Research Group; IDIBAPS; E-08036 Barcelona, Spain
- Faculté de Biologie; UPMC Sorbonne Universités; Paris, F-75005, France
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36
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Aduri R, Briggs KT, Gorelick RJ, Marino JP. Molecular determinants of HIV-1 NCp7 chaperone activity in maturation of the HIV-1 dimerization initiation site. Nucleic Acids Res 2012; 41:2565-80. [PMID: 23275531 PMCID: PMC3575791 DOI: 10.1093/nar/gks1350] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Human immunodeficiency virus genome dimerization is initiated through an RNA-RNA kissing interaction formed via the dimerization initiation site (DIS) loop sequence, which has been proposed to be converted to a more thermodynamically stable linkage by the viral p7 form of the nucleocapsid protein (NC). Here, we systematically probed the role of specific amino acids of NCp7 in its chaperone activity in the DIS conversion using 2-aminopurine (2-AP) fluorescence and nuclear magnetic resonance spectroscopy. Through comparative analysis of NCp7 mutants, the presence of positively charged residues in the N-terminus was found to be essential for both helix destabilization and strand transfer functions. It was also observed that the presence and type of the Zn finger is important for NCp7 chaperone activity, but not the order of the Zn fingers. Swapping single aromatic residues between Zn fingers had a significant effect on NCp7 activity; however, these mutants did not exhibit the same activity as mutants in which the order of the Zn fingers was changed, indicating a functional role for other flanking residues. RNA chaperone activity is further correlated with NCp7 structure and interaction with RNA through comparative analysis of nuclear magnetic resonance spectra of NCp7 variants, and complexes of these proteins with the DIS dimer.
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Affiliation(s)
- Raviprasad Aduri
- Institute for Bioscience and Biotechnology Research of the University of Maryland and the National Institute of Standards and Technology, Rockville, MD 20850, USA
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37
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Krishnan L, Engelman A. Retroviral integrase proteins and HIV-1 DNA integration. J Biol Chem 2012; 287:40858-66. [PMID: 23043109 DOI: 10.1074/jbc.r112.397760] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Retroviral integrases catalyze two reactions, 3'-processing of viral DNA ends, followed by integration of the processed ends into chromosomal DNA. X-ray crystal structures of integrase-DNA complexes from prototype foamy virus, a member of the Spumavirus genus of Retroviridae, have revealed the structural basis of integration and how clinically relevant integrase strand transfer inhibitors work. Underscoring the translational potential of targeting virus-host interactions, small molecules that bind at the host factor lens epithelium-derived growth factor/p75-binding site on HIV-1 integrase promote dimerization and inhibit integrase-viral DNA assembly and catalysis. Here, we review recent advances in our knowledge of HIV-1 DNA integration, as well as future research directions.
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Affiliation(s)
- Lavanya Krishnan
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
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38
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Warui DM, Baranger AM. Identification of small molecule inhibitors of the HIV-1 nucleocapsid-stem-loop 3 RNA complex. J Med Chem 2012; 55:4132-41. [PMID: 22480197 DOI: 10.1021/jm2007694] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Stem-loop 3 RNA (SL3) in ψ-RNA is a highly conserved motif in different strains of HIV-1 and serves as a principle determinant for viral packaging. Viral encapsulation is critical for viral replication, and disruption of the nucleocapsid-ψ-RNA complex interferes with viral replication. We have used SL3 RNA as a target for identification of small molecule inhibitors of the interactions of nucleocapsid protein (NCp7) and ψ-RNA. We report the use of computational and high-throughput screening approaches to identify 16 compounds that bind SL3 RNA with micromolar affinities. Among the identified ligands, two molecules, compounds 7 and 17, bind with higher affinity to SL3 RNA than to double- and single-stranded RNAs. Four of the 16 SL3 RNA ligands inhibit interactions between SL3 RNA and NCp7 with micromolar inhibition constants. In general, the identified SL3 ligands have simple molecular structures and low molecular weights and are, therefore, possible lead compounds for the development of ligands that target the elements of ψ-RNA of HIV-1 with high affinity and specificity.
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Affiliation(s)
- Douglas M Warui
- Department of Chemistry, 361 Roger Adams Laboratory, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
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39
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Correlation of recombinant integrase activity and functional preintegration complex formation during acute infection by replication-defective integrase mutant human immunodeficiency virus. J Virol 2012; 86:3861-79. [PMID: 22278243 DOI: 10.1128/jvi.06386-11] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Previous studies characterized two types of replication-defective human immunodeficiency virus type 1 (HIV-1) integrase mutants: class I, which are specifically blocked at the integration step, and class II, which harbor additional virion production and/or reverse transcription defects. Class I mutant enzymes supported little if any metal ion-dependent 3'-processing and DNA strand transfer activities in vitro, whereas class II enzymes displayed partial or full catalytic function in studies with simplified assay designs, suggesting that defective interaction(s) with heterologous integrase binding proteins might underlie the class II mutant viral phenotype. To address this hypothesis, class I and II mutant enzymes were interrogated under expanded sets of in vitro conditions. The majority failed to catalyze the concerted integration of two viral DNA ends into target DNA, highlighting defective integrase function as the root cause of most class II in addition to all class I mutant virus infection defects. One mutant protein, K264E, in contrast, could support the wild-type level of concerted integration activity. After accounting for its inherent reverse transcription defect, HIV-1(K264E) moreover formed preintegration complexes that supported the efficient integration of endogenous viral DNA in vitro and normal levels and sequences of 2-long terminal repeat-containing circle junctions during acute infection. K264E integrase furthermore efficiently interacted in vitro with two heterologous binding partners, LEDGF/p75 and reverse transcriptase. Our results underscore the physiological relevance of concerted integration assays for tests of integrase mutant function and suggest that the K264E mutation disrupts an interaction with an intranuclear integrase binding partner that is important for HIV-1 integration.
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40
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Ivanyi-Nagy R, Darlix JL. Fuzziness in the Core of the Human Pathogenic Viruses HCV and HIV. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 725:142-58. [DOI: 10.1007/978-1-4614-0659-4_9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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41
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Flexible nature and specific functions of the HIV-1 nucleocapsid protein. J Mol Biol 2011; 410:565-81. [PMID: 21762801 DOI: 10.1016/j.jmb.2011.03.037] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 03/14/2011] [Accepted: 03/17/2011] [Indexed: 01/04/2023]
Abstract
One salient feature of reverse transcription in retroviruses, notably in the human immunodeficiency virus type 1, is that it requires the homologous nucleocapsid (NC) protein acting as a chaperoning partner of the genomic RNA template and the reverse transcriptase, from the initiation to the completion of viral DNA synthesis. This short review on the NC protein of human immunodeficiency virus type 1 aims at briefly presenting the flexible nature of NC protein, how it interacts with nucleic acids via its invariant zinc fingers and flanking basic residues, and the possible mechanisms that account for its multiple functions in the early steps of virus replication, notably in the obligatory strand transfer reactions during viral DNA synthesis by the reverse transcriptase enzyme.
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42
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Kessl JJ, Li M, Ignatov M, Shkriabai N, Eidahl JO, Feng L, Musier-Forsyth K, Craigie R, Kvaratskhelia M. FRET analysis reveals distinct conformations of IN tetramers in the presence of viral DNA or LEDGF/p75. Nucleic Acids Res 2011; 39:9009-22. [PMID: 21771857 PMCID: PMC3203615 DOI: 10.1093/nar/gkr581] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A tetramer of HIV-1 integrase (IN) stably associates with the viral DNA ends to form a fully functional concerted integration intermediate. LEDGF/p75, a key cellular binding partner of the lentiviral enzyme, also stabilizes a tetrameric form of IN. However, functional assays have indicated the importance of the order of viral DNA and LEDGF/p75 addition to IN for productive concerted integration. Here, we employed Förster Resonance Energy Transfer (FRET) to monitor assembly of individual IN subunits into tetramers in the presence of viral DNA and LEDGF/p75. The IN–viral DNA and IN–LEDGF/p75 complexes yielded significantly different FRET values suggesting two distinct IN conformations in these complexes. Furthermore, the order of addition experiments indicated that FRET for the preformed IN–viral DNA complex remained unchanged upon its subsequent binding to LEDGF/p75, whereas pre-incubation of LEDGF/p75 and IN followed by addition of viral DNA yielded FRET very similar to the IN–LEDGF/p75 complex. These findings provide new insights into the structural organization of IN subunits in functional concerted integration intermediates and suggest that differential multimerization of IN in the presence of various ligands could be exploited as a plausible therapeutic target for development of allosteric inhibitors.
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Affiliation(s)
- Jacques J Kessl
- Center for Retrovirus Research and Comprehensive Cancer Center, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
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43
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Thomas JA, Shatzer TL, Gorelick RJ. Blocking premature reverse transcription fails to rescue the HIV-1 nucleocapsid-mutant replication defect. Retrovirology 2011; 8:46. [PMID: 21682883 PMCID: PMC3141651 DOI: 10.1186/1742-4690-8-46] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Accepted: 06/17/2011] [Indexed: 02/06/2023] Open
Abstract
Background The nucleocapsid (NC) protein of HIV-1 is critical for viral replication. Mutational analyses have demonstrated its involvement in viral assembly, genome packaging, budding, maturation, reverse transcription, and integration. We previously reported that two conservative NC mutations, His23Cys and His44Cys, cause premature reverse transcription such that mutant virions contain approximately 1,000-fold more DNA than wild-type virus, and are replication defective. In addition, both mutants show a specific defect in integration after infection. Results In the present study we investigated whether blocking premature reverse transcription would relieve the infectivity defects, which we successfully performed by transfecting proviral plasmids into cells cultured in the presence of high levels of reverse transcriptase inhibitors. After subsequent removal of the inhibitors, the resulting viruses showed no significant difference in single-round infective titer compared to viruses where premature reverse transcription did occur; there was no rescue of the infectivity defects in the NC mutants upon reverse transcriptase inhibitor treatment. Surprisingly, time-course endogenous reverse transcription assays demonstrated that the kinetics for both the NC mutants were essentially identical to wild-type when premature reverse transcription was blocked. In contrast, after infection of CD4+ HeLa cells, it was observed that while the prevention of premature reverse transcription in the NC mutants resulted in lower quantities of initial reverse transcripts, the kinetics of reverse transcription were not restored to that of untreated wild-type HIV-1. Conclusions Premature reverse transcription is not the cause of the replication defect but is an independent side-effect of the NC mutations.
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Affiliation(s)
- James A Thomas
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc,, NCI at Frederick, Frederick, MD 21702, USA
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44
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Zamborlini A, Coiffic A, Beauclair G, Delelis O, Paris J, Koh Y, Magne F, Giron ML, Tobaly-Tapiero J, Deprez E, Emiliani S, Engelman A, de Thé H, Saïb A. Impairment of human immunodeficiency virus type-1 integrase SUMOylation correlates with an early replication defect. J Biol Chem 2011; 286:21013-22. [PMID: 21454548 PMCID: PMC3121452 DOI: 10.1074/jbc.m110.189274] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 02/23/2011] [Indexed: 11/06/2022] Open
Abstract
HIV-1 integrase (IN) orchestrates the integration of the reverse transcribed viral cDNA into the host cell genome and participates also in other steps of HIV-1 replication. Cellular and viral factors assist IN in performing its multiple functions, and post-translational modifications contribute to modulate its activities. Here, we show that HIV-1 IN is modified by SUMO proteins and that phylogenetically conserved SUMOylation consensus motifs represent major SUMO acceptor sites. Viruses harboring SUMOylation site IN mutants displayed a replication defect that was mapped during the early stages of infection, before integration but after reverse transcription. Because SUMOylation-defective IN mutants retained WT catalytic activity, we hypothesize that SUMOylation might regulate the affinity of IN for co-factors, contributing to efficient HIV-1 replication.
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Affiliation(s)
- Alessia Zamborlini
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
- the Conservatoire des Arts et Métiers, Paris, France
| | - Audrey Coiffic
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
| | - Guillaume Beauclair
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
| | - Olivier Delelis
- Laboratoire de Biotechnologies et Pharmacologie Génétique Appliquée, CNRS UMR8113, Ecole Normale Supérieure, 94235 Cachan, France
| | - Joris Paris
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
| | - Yashuiro Koh
- the Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts 02215
| | - Fabian Magne
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
- the Conservatoire des Arts et Métiers, Paris, France
| | - Marie-Lou Giron
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
| | - Joelle Tobaly-Tapiero
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
| | - Eric Deprez
- Laboratoire de Biotechnologies et Pharmacologie Génétique Appliquée, CNRS UMR8113, Ecole Normale Supérieure, 94235 Cachan, France
| | - Stephane Emiliani
- INSERM U1016, CNRS UMR8104, Université Paris Descartes, Institut Cochin, 75014 Paris, France, and
| | - Alan Engelman
- the Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts 02215
| | - Hugues de Thé
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
| | - Ali Saïb
- From the CNRS UMR7212, INSERM U944, Institut Universitaire d'Hématologie-Université Paris7 Diderot, 75475 Paris, France
- the Conservatoire des Arts et Métiers, Paris, France
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45
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Comparative analysis of RNA/protein dynamics for the arginine-rich-binding motif and zinc-finger-binding motif proteins encoded by HIV-1. Biophys J 2011; 99:3454-62. [PMID: 21081095 DOI: 10.1016/j.bpj.2010.09.051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 09/28/2010] [Accepted: 09/28/2010] [Indexed: 11/24/2022] Open
Abstract
We report a comparative study in which a single-molecule fluorescence resonance energy transfer approach was used to examine how the binding of two families of HIV-1 viral proteins to viral RNA hairpins locally changes the RNA secondary structures. The single-molecule fluorescence resonance energy transfer results indicate that the zinc finger protein (nucleocapsid) locally melts the TAR RNA and RRE-IIB RNA hairpins, whereas arginine-rich motif proteins (Tat and Rev) may strengthen the hairpin structures through specific binding interactions. Competition experiments show that Tat and Rev can effectively inhibit the nucleocapsid-chaperoned annealing of complementary DNA oligonucleotides to the TAR and RRE-IIB RNA hairpins, respectively. The competition binding data presented here suggest that the specific nucleic acid binding interactions of Tat and Rev can effectively compete with the general nucleic acid binding/chaperone functions of the nucleocapsid protein, and thus may in principle help regulate critical events during the HIV life cycle.
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46
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Piekna-Przybylska D, Bambara RA. Requirements for efficient minus strand strong-stop DNA transfer in human immunodeficiency virus 1. RNA Biol 2011; 8:230-6. [PMID: 21444998 DOI: 10.4161/rna.8.2.14802] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
After HIV-1 enters a human cell, its RNA genome is converted into double stranded DNA during the multistep process of reverse transcription. First (minus) strand DNA synthesis is initiated near the 5' end of the viral RNA, where only a short fragment of the genome is copied. In order to continue DNA synthesis the virus employs a complicated mechanism, which enables transferring of the growing minus strand DNA to a remote position at the genomic 3' end. This is called minus strand DNA transfer. The transfer enables regeneration of long terminal repeat sequences, which are crucial for viral genomic DNA integration into the host chromosome. Numerous factors have been identified that stimulate minus strand DNA transfer. In this review we focus on describing protein-RNA and RNA-RNA interactions, as well as RNA structural features, known to facilitate this step in reverse transcription.
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Affiliation(s)
- Dorota Piekna-Przybylska
- Department of Biochemistry and Biophysics, and the Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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47
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Li X, Krishnan L, Cherepanov P, Engelman A. Structural biology of retroviral DNA integration. Virology 2011; 411:194-205. [PMID: 21216426 DOI: 10.1016/j.virol.2010.12.008] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Accepted: 12/06/2010] [Indexed: 02/06/2023]
Abstract
Three-dimensional macromolecular structures shed critical light on biological mechanism and facilitate development of small molecule inhibitors. Clinical success of raltegravir, a potent inhibitor of HIV-1 integrase, demonstrated the utility of this viral DNA recombinase as an antiviral target. A variety of partial integrase structures reported in the past 16 years have been instrumental and very informative to the field. Nonetheless, because integrase protein fragments are unable to functionally engage the viral DNA substrate critical for strand transfer inhibitor binding, the early structures did little to materially impact drug development efforts. However, recent results based on prototype foamy virus integrase have fully reversed this trend, as a number of X-ray crystal structures of active integrase-DNA complexes revealed key mechanistic details and moreover established the foundation of HIV-1 integrase strand transfer inhibitor action. In this review we discuss the landmarks in the progress of integrase structural biology during the past 17 years.
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Affiliation(s)
- Xiang Li
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115, USA
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Levin JG, Mitra M, Mascarenhas A, Musier-Forsyth K. Role of HIV-1 nucleocapsid protein in HIV-1 reverse transcription. RNA Biol 2010; 7:754-74. [PMID: 21160280 DOI: 10.4161/rna.7.6.14115] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The HIV-1 nucleocapsid protein (NC) is a nucleic acid chaperone, which remodels nucleic acid structures so that the most thermodynamically stable conformations are formed. This activity is essential for virus replication and has a critical role in mediating highly specific and efficient reverse transcription. NC's function in this process depends upon three properties: (1) ability to aggregate nucleic acids; (2) moderate duplex destabilization activity; and (3) rapid on-off binding kinetics. Here, we present a detailed molecular analysis of the individual events that occur during viral DNA synthesis and show how NC's properties are important for almost every step in the pathway. Finally, we also review biological aspects of reverse transcription during infection and the interplay between NC, reverse transcriptase, and human APOBEC3G, an HIV-1 restriction factor that inhibits reverse transcription and virus replication in the absence of the HIV-1 Vif protein.
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Affiliation(s)
- Judith G Levin
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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Wu T, Datta SA, Mitra M, Gorelick RJ, Rein A, Levin JG. Fundamental differences between the nucleic acid chaperone activities of HIV-1 nucleocapsid protein and Gag or Gag-derived proteins: biological implications. Virology 2010; 405:556-67. [PMID: 20655566 PMCID: PMC2963451 DOI: 10.1016/j.virol.2010.06.042] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 05/16/2010] [Accepted: 06/23/2010] [Indexed: 01/31/2023]
Abstract
The HIV-1 Gag polyprotein precursor has multiple domains including nucleocapsid (NC). Although mature NC and NC embedded in Gag are nucleic acid chaperones (proteins that remodel nucleic acid structure), few studies include detailed analysis of the chaperone activity of partially processed Gag proteins and comparison with NC and Gag. Here we address this issue by using a reconstituted minus-strand transfer system. NC and NC-containing Gag proteins exhibited annealing and duplex destabilizing activities required for strand transfer. Surprisingly, unlike NC, with increasing concentrations, Gag proteins drastically inhibited the DNA elongation step. This result is consistent with "nucleic acid-driven multimerization" of Gag and the reported slow dissociation of Gag from bound nucleic acid, which prevent reverse transcriptase from traversing the template ("roadblock" mechanism). Our findings illustrate one reason why NC (and not Gag) has evolved as a critical cofactor in reverse transcription, a paradigm that might also extend to other retrovirus systems.
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Affiliation(s)
- Tiyun Wu
- Laboratory of Molecular Genetics, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Building 6B, Room 216, 6 Center Drive, Bethesda, MD 20892-2780, USA
| | - Siddhartha A.K. Datta
- HIV Drug Resistance Program, National Cancer Institute-Frederick, Frederick, MD 21702-1201, USA
| | - Mithun Mitra
- Laboratory of Molecular Genetics, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Building 6B, Room 216, 6 Center Drive, Bethesda, MD 20892-2780, USA
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, SAIC-Frederick, Inc., National Cancer Institute-Frederick, Frederick, MD 21702-1201, USA
| | - Alan Rein
- HIV Drug Resistance Program, National Cancer Institute-Frederick, Frederick, MD 21702-1201, USA
| | - Judith G. Levin
- Laboratory of Molecular Genetics, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Building 6B, Room 216, 6 Center Drive, Bethesda, MD 20892-2780, USA
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Chaurasiya KR, Paramanathan T, McCauley MJ, Williams MC. Biophysical characterization of DNA binding from single molecule force measurements. Phys Life Rev 2010; 7:299-341. [PMID: 20576476 DOI: 10.1016/j.plrev.2010.06.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 05/19/2010] [Accepted: 05/20/2010] [Indexed: 11/25/2022]
Abstract
Single molecule force spectroscopy is a powerful method that uses the mechanical properties of DNA to explore DNA interactions. Here we describe how DNA stretching experiments quantitatively characterize the DNA binding of small molecules and proteins. Small molecules exhibit diverse DNA binding modes, including binding into the major and minor grooves and intercalation between base pairs of double-stranded DNA (dsDNA). Histones bind and package dsDNA, while other nuclear proteins such as high mobility group proteins bind to the backbone and bend dsDNA. Single-stranded DNA (ssDNA) binding proteins slide along dsDNA to locate and stabilize ssDNA during replication. Other proteins exhibit binding to both dsDNA and ssDNA. Nucleic acid chaperone proteins can switch rapidly between dsDNA and ssDNA binding modes, while DNA polymerases bind both forms of DNA with high affinity at distinct binding sites at the replication fork. Single molecule force measurements quantitatively characterize these DNA binding mechanisms, elucidating small molecule interactions and protein function.
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Affiliation(s)
- Kathy R Chaurasiya
- Department of Physics, Northeastern University, 111 Dana Research Center, Boston, MA 02115, USA
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