1
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Heng X, Herrera AP, Song Z, Boris-Lawrie K. Retroviral PBS-segment sequence and structure: Orchestrating early and late replication events. Retrovirology 2024; 21:12. [PMID: 38886829 PMCID: PMC11181671 DOI: 10.1186/s12977-024-00646-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 06/06/2024] [Indexed: 06/20/2024] Open
Abstract
An essential regulatory hub for retroviral replication events, the 5' untranslated region (UTR) encodes an ensemble of cis-acting replication elements that overlap in a logical manner to carry out divergent RNA activities in cells and in virions. The primer binding site (PBS) and primer activation sequence initiate the reverse transcription process in virions, yet overlap with structural elements that regulate expression of the complex viral proteome. PBS-segment also encompasses the attachment site for Integrase to cut and paste the 3' long terminal repeat into the host chromosome to form the provirus and purine residues necessary to execute the precise stoichiometry of genome-length transcripts and spliced viral RNAs. Recent genetic mapping, cofactor affinity experiments, NMR and SAXS have elucidated that the HIV-1 PBS-segment folds into a three-way junction structure. The three-way junction structure is recognized by the host's nuclear RNA helicase A/DHX9 (RHA). RHA tethers host trimethyl guanosine synthase 1 to the Rev/Rev responsive element (RRE)-containing RNAs for m7-guanosine Cap hyper methylation that bolsters virion infectivity significantly. The HIV-1 trimethylated (TMG) Cap licenses specialized translation of virion proteins under conditions that repress translation of the regulatory proteins. Clearly host-adaption and RNA shapeshifting comprise the fundamental basis for PBS-segment orchestrating both reverse transcription of virion RNA and the nuclear modification of m7G-Cap for biphasic translation of the complex viral proteome. These recent observations, which have exposed even greater complexity of retroviral RNA biology than previously established, are the impetus for this article. Basic research to fully comprehend the marriage of PBS-segment structures and host RNA binding proteins that carry out retroviral early and late replication events is likely to expose an immutable virus-specific therapeutic target to attenuate retrovirus proliferation.
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Affiliation(s)
- Xiao Heng
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA.
| | - Amanda Paz Herrera
- Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Zhenwei Song
- Department of Veterinary and Biomedical Sciences, Institute for Molecular Virology, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Kathleen Boris-Lawrie
- Department of Veterinary and Biomedical Sciences, Institute for Molecular Virology, University of Minnesota, Saint Paul, MN, 55108, USA.
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2
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Uppuladinne MVN, Achalere A, Sonavane U, Joshi R. Probing the structure of human tRNA 3Lys in the presence of ligands using docking, MD simulations and MSM analysis. RSC Adv 2023; 13:25778-25796. [PMID: 37655355 PMCID: PMC10467029 DOI: 10.1039/d3ra03694d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/14/2023] [Indexed: 09/02/2023] Open
Abstract
The tRNA3Lys, which acts as a primer for human immunodeficiency virus type 1 (HIV-1) reverse transcription, undergoes structural changes required for the formation of a primer-template complex. Small molecules have been targeted against tRNA3Lys to inhibit the primer-template complex formation. The present study aims to understand the kinetics of the conformational landscape spanned by tRNA3Lys in apo form using molecular dynamics simulations and Markov state modeling. The study is taken further to investigate the effect of small molecules like 1,4T and 1,5T on structural conformations and kinetics of tRNA3Lys, and comparative analysis is presented. Markov state modeling of tRNA3Lys apo resulted in three metastable states where the conformations have shown the non-canonical structures of the anticodon loop. Based on analyses of ligand-tRNA3Lys interactions, crucial ion and water mediated H-bonds and free energy calculations, it was observed that the 1,4-triazole more strongly binds to the tRNA3Lys compared to 1,5-triazole. However, the MSM analysis suggest that the 1,5-triazole binding to tRNA3Lys has brought rigidity not only in the binding pocket (TΨC arm, D-TΨC loop) but also in the whole structure of tRNA3Lys. This may affect the easy opening of primer tRNA3Lys required for HIV-1 reverse transcription.
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Affiliation(s)
- Mallikarjunachari V N Uppuladinne
- High Performance Computing - Medical and Bioinformatics Applications, Centre for Development of Advanced Computing (C-DAC) Panchavati, Pashan Pune India
| | - Archana Achalere
- High Performance Computing - Medical and Bioinformatics Applications, Centre for Development of Advanced Computing (C-DAC) Panchavati, Pashan Pune India
| | - Uddhavesh Sonavane
- High Performance Computing - Medical and Bioinformatics Applications, Centre for Development of Advanced Computing (C-DAC) Panchavati, Pashan Pune India
| | - Rajendra Joshi
- High Performance Computing - Medical and Bioinformatics Applications, Centre for Development of Advanced Computing (C-DAC) Panchavati, Pashan Pune India
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3
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Boyd PS, Brown JB, Brown JD, Catazaro J, Chaudry I, Ding P, Dong X, Marchant J, O’Hern CT, Singh K, Swanson C, Summers MF, Yasin S. NMR Studies of Retroviral Genome Packaging. Viruses 2020; 12:v12101115. [PMID: 33008123 PMCID: PMC7599994 DOI: 10.3390/v12101115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/18/2020] [Accepted: 09/26/2020] [Indexed: 12/03/2022] Open
Abstract
Nearly all retroviruses selectively package two copies of their unspliced RNA genomes from a cellular milieu that contains a substantial excess of non-viral and spliced viral RNAs. Over the past four decades, combinations of genetic experiments, phylogenetic analyses, nucleotide accessibility mapping, in silico RNA structure predictions, and biophysical experiments were employed to understand how retroviral genomes are selected for packaging. Genetic studies provided early clues regarding the protein and RNA elements required for packaging, and nucleotide accessibility mapping experiments provided insights into the secondary structures of functionally important elements in the genome. Three-dimensional structural determinants of packaging were primarily derived by nuclear magnetic resonance (NMR) spectroscopy. A key advantage of NMR, relative to other methods for determining biomolecular structure (such as X-ray crystallography), is that it is well suited for studies of conformationally dynamic and heterogeneous systems—a hallmark of the retrovirus packaging machinery. Here, we review advances in understanding of the structures, dynamics, and interactions of the proteins and RNA elements involved in retroviral genome selection and packaging that are facilitated by NMR.
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4
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Mouhand A, Pasi M, Catala M, Zargarian L, Belfetmi A, Barraud P, Mauffret O, Tisné C. Overview of the Nucleic-Acid Binding Properties of the HIV-1 Nucleocapsid Protein in Its Different Maturation States. Viruses 2020; 12:v12101109. [PMID: 33003650 PMCID: PMC7601788 DOI: 10.3390/v12101109] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/23/2020] [Accepted: 09/26/2020] [Indexed: 12/17/2022] Open
Abstract
HIV-1 Gag polyprotein orchestrates the assembly of viral particles. Its C-terminus consists of the nucleocapsid (NC) domain that interacts with nucleic acids, and p1 and p6, two unstructured regions, p6 containing the motifs to bind ALIX, the cellular ESCRT factor TSG101 and the viral protein Vpr. The processing of Gag by the viral protease subsequently liberates NCp15 (NC-p1-p6), NCp9 (NC-p1) and NCp7, NCp7 displaying the optimal chaperone activity of nucleic acids. This review focuses on the nucleic acid binding properties of the NC domain in the different maturation states during the HIV-1 viral cycle.
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Affiliation(s)
- Assia Mouhand
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Marco Pasi
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Marjorie Catala
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Loussiné Zargarian
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Anissa Belfetmi
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Pierre Barraud
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Olivier Mauffret
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
- Correspondence: (O.M.); (C.T.)
| | - Carine Tisné
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
- Correspondence: (O.M.); (C.T.)
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5
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How HIV-1 Gag Manipulates Its Host Cell Proteins: A Focus on Interactors of the Nucleocapsid Domain. Viruses 2020; 12:v12080888. [PMID: 32823718 PMCID: PMC7471995 DOI: 10.3390/v12080888] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/06/2020] [Accepted: 08/10/2020] [Indexed: 12/27/2022] Open
Abstract
The human immunodeficiency virus (HIV-1) polyprotein Gag (Group-specific antigen) plays a central role in controlling the late phase of the viral lifecycle. Considered to be only a scaffolding protein for a long time, the structural protein Gag plays determinate and specific roles in HIV-1 replication. Indeed, via its different domains, Gag orchestrates the specific encapsidation of the genomic RNA, drives the formation of the viral particle by its auto-assembly (multimerization), binds multiple viral proteins, and interacts with a large number of cellular proteins that are needed for its functions from its translation location to the plasma membrane, where newly formed virions are released. Here, we review the interactions between HIV-1 Gag and 66 cellular proteins. Notably, we describe the techniques used to evidence these interactions, the different domains of Gag involved, and the implications of these interactions in the HIV-1 replication cycle. In the final part, we focus on the interactions involving the highly conserved nucleocapsid (NC) domain of Gag and detail the functions of the NC interactants along the viral lifecycle.
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6
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Marušič M, Schlagnitweit J, Petzold K. RNA Dynamics by NMR Spectroscopy. Chembiochem 2019; 20:2685-2710. [PMID: 30997719 PMCID: PMC6899578 DOI: 10.1002/cbic.201900072] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/12/2019] [Indexed: 12/22/2022]
Abstract
An ever-increasing number of functional RNAs require a mechanistic understanding. RNA function relies on changes in its structure, so-called dynamics. To reveal dynamic processes and higher energy structures, new NMR methods have been developed to elucidate these dynamics in RNA with atomic resolution. In this Review, we provide an introduction to dynamics novices and an overview of methods that access most dynamic timescales, from picoseconds to hours. Examples are provided as well as insight into theory, data acquisition and analysis for these different methods. Using this broad spectrum of methodology, unprecedented detail and invisible structures have been obtained and are reviewed here. RNA, though often more complicated and therefore neglected, also provides a great system to study structural changes, as these RNA structural changes are more easily defined-Lego like-than in proteins, hence the numerous revelations of RNA excited states.
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Affiliation(s)
- Maja Marušič
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
| | - Judith Schlagnitweit
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
| | - Katja Petzold
- Department of Medical Biochemistry and BiophysicsKarolinska InstitutetSolnavägen 917177StockholmSweden
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7
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Bou-Nader C, Barraud P, Pecqueur L, Pérez J, Velours C, Shepard W, Fontecave M, Tisné C, Hamdane D. Molecular basis for transfer RNA recognition by the double-stranded RNA-binding domain of human dihydrouridine synthase 2. Nucleic Acids Res 2019; 47:3117-3126. [PMID: 30605527 PMCID: PMC6451096 DOI: 10.1093/nar/gky1302] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/12/2018] [Accepted: 12/29/2018] [Indexed: 11/17/2022] Open
Abstract
Double stranded RNA-binding domain (dsRBD) is a ubiquitous domain specialized in the recognition of double-stranded RNAs (dsRNAs). Present in many proteins and enzymes involved in various functional roles of RNA metabolism, including RNA splicing, editing, and transport, dsRBD generally binds to RNAs that lack complex structures. However, this belief has recently been challenged by the discovery of a dsRBD serving as a major tRNA binding module for human dihydrouridine synthase 2 (hDus2), a flavoenzyme that catalyzes synthesis of dihydrouridine within the complex elbow structure of tRNA. We here unveil the molecular mechanism by which hDus2 dsRBD recognizes a tRNA ligand. By solving the crystal structure of this dsRBD in complex with a dsRNA together with extensive characterizations of its interaction with tRNA using mutagenesis, NMR and SAXS, we establish that while hDus2 dsRBD retains a conventional dsRNA recognition capability, the presence of an N-terminal extension appended to the canonical domain provides additional residues for binding tRNA in a structure-specific mode of action. Our results support that this extension represents a feature by which the dsRBD specializes in tRNA biology and more broadly highlight the importance of structural appendages to canonical domains in promoting the emergence of functional diversity.
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Affiliation(s)
- Charles Bou-Nader
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Pierre Barraud
- Institut de biologie physico-chimique (IBPC), CNRS, UMR 8261 CNRS/Université Paris Diderot, 13 rue Pierre et Marie Curie, Paris 75005, France.,Laboratoire de cristallographie et RMN biologiques, UMR 8015, CNRS, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Ludovic Pecqueur
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Javier Pérez
- Synchrotron Soleil, L'Orme des Merisiers, BP 48, 91192 Gif sur Yvette Cedex, France
| | - Christophe Velours
- Macromolecular interaction platform of I2BC, UMR9198, Centre de Recherche de Gif-sur-Yvette, France
| | - William Shepard
- Synchrotron Soleil, L'Orme des Merisiers, BP 48, 91192 Gif sur Yvette Cedex, France
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
| | - Carine Tisné
- Institut de biologie physico-chimique (IBPC), CNRS, UMR 8261 CNRS/Université Paris Diderot, 13 rue Pierre et Marie Curie, Paris 75005, France.,Laboratoire de cristallographie et RMN biologiques, UMR 8015, CNRS, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Djemel Hamdane
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France
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8
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Mouhand A, Belfetmi A, Catala M, Larue V, Zargarian L, Brachet F, Gorelick RJ, Van Heijenoort C, Mirambeau G, Barraud P, Mauffret O, Tisné C. Modulation of the HIV nucleocapsid dynamics finely tunes its RNA-binding properties during virion genesis. Nucleic Acids Res 2019; 46:9699-9710. [PMID: 29986076 PMCID: PMC6182130 DOI: 10.1093/nar/gky612] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 06/26/2018] [Indexed: 02/06/2023] Open
Abstract
During HIV-1 assembly and budding, Gag protein, in particular the C-terminal domain containing the nucleocapsid domain (NCd), p1 and p6, is the site of numerous interactions with viral and cellular factors. Most in vitro studies of Gag have used constructs lacking p1 and p6. Here, using NMR spectroscopy, we show that the p1-p6 region of Gag (NCp15) is largely disordered, but interacts transiently with the NCd. These interactions modify the dynamic properties of the NCd. Indeed, using isothermal titration calorimetry (ITC), we have measured a higher entropic penalty to RNA-binding for the NCd precursor, NCp15, than for the mature form, NCp7, which lacks p1 and p6. We propose that during assembly and budding of virions, concomitant with Gag oligomerization, transient interactions between NCd and p1-p6 become salient and responsible for (i) a higher level of structuration of p6, which favours recruitment of budding partners; and (ii) a higher entropic penalty to RNA-binding at specific sites that favours non-specific binding of NCd at multiple sites on the genomic RNA (gRNA). The contributions of p6 and p1 are sequentially removed via proteolysis during Gag maturation such that the RNA-binding specificity of the mature protein is governed by the properties of NCd.
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Affiliation(s)
- Assia Mouhand
- Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, USPC, 4 avenue de l'Observatoire, 75006 Paris, France.,Laboratoire d'Expression génétique microbienne, IBPC, CNRS, Université Paris Diderot, USPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Anissa Belfetmi
- LBPA, CNRS UMR 8113, ENS Paris-Saclay, Université Paris-Saclay, 61 Avenue du Pdt Wilson, F-94235 Cachan, France
| | - Marjorie Catala
- Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, USPC, 4 avenue de l'Observatoire, 75006 Paris, France.,Laboratoire d'Expression génétique microbienne, IBPC, CNRS, Université Paris Diderot, USPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Valéry Larue
- Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, USPC, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Loussiné Zargarian
- LBPA, CNRS UMR 8113, ENS Paris-Saclay, Université Paris-Saclay, 61 Avenue du Pdt Wilson, F-94235 Cachan, France
| | - Franck Brachet
- Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, USPC, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, MD 21702-1201, USA
| | - Carine Van Heijenoort
- Institut de Chimie des Substances Naturelles, CNRS UPR2301, Univ. Paris Sud, Université Paris-Saclay, Avenue de la Terrasse, 91190 Gif-sur-Yvette, France
| | - Gilles Mirambeau
- Infectious disease & AIDS Research unit, IDIBAPS, Barcelona, Barcelona, Spain.,Sorbonne Université, Faculté des Sciences et Ingénierie, UFR 927 des Sciences de la Vie, Paris, France
| | - Pierre Barraud
- Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, USPC, 4 avenue de l'Observatoire, 75006 Paris, France.,Laboratoire d'Expression génétique microbienne, IBPC, CNRS, Université Paris Diderot, USPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Olivier Mauffret
- LBPA, CNRS UMR 8113, ENS Paris-Saclay, Université Paris-Saclay, 61 Avenue du Pdt Wilson, F-94235 Cachan, France
| | - Carine Tisné
- Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, USPC, 4 avenue de l'Observatoire, 75006 Paris, France.,Laboratoire d'Expression génétique microbienne, IBPC, CNRS, Université Paris Diderot, USPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
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9
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Belfetmi A, Zargarian L, Tisné C, Sleiman D, Morellet N, Lescop E, Maskri O, René B, Mély Y, Fossé P, Mauffret O. Insights into the mechanisms of RNA secondary structure destabilization by the HIV-1 nucleocapsid protein. RNA (NEW YORK, N.Y.) 2016; 22:506-517. [PMID: 26826129 PMCID: PMC4793207 DOI: 10.1261/rna.054445.115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 12/06/2015] [Indexed: 06/05/2023]
Abstract
The mature HIV-1 nucleocapsid protein NCp7 (NC) plays a key role in reverse transcription facilitating the two obligatory strand transfers. Several properties contribute to its efficient chaperon activity: preferential binding to single-stranded regions, nucleic acid aggregation, helix destabilization, and rapid dissociation from nucleic acids. However, little is known about the relationships between these different properties, which are complicated by the ability of the protein to recognize particular HIV-1 stem-loops, such as SL1, SL2, and SL3, with high affinity and without destabilizing them. These latter properties are important in the context of genome packaging, during which NC is part of the Gag precursor. We used NMR to investigate destabilization of the full-length TAR (trans activating response element) RNA by NC, which is involved in the first strand transfer step of reverse transcription. NC was used at a low protein:nucleotide (nt) ratio of 1:59 in these experiments. NMR data for the imino protons of TAR identified most of the base pairs destabilized by NC. These base pairs were adjacent to the loops in the upper part of the TAR hairpin rather than randomly distributed. Gel retardation assays showed that conversion from the initial TAR-cTAR complex to the fully annealed form occurred much more slowly at the 1:59 ratio than at the higher ratios classically used. Nevertheless, NC significantly accelerated the formation of the initial complex at a ratio of 1:59.
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Affiliation(s)
- Anissa Belfetmi
- LBPA, ENS de Cachan, CNRS, Université Paris-Saclay, 94235 Cachan Cedex, France
| | - Loussiné Zargarian
- LBPA, ENS de Cachan, CNRS, Université Paris-Saclay, 94235 Cachan Cedex, France
| | - Carine Tisné
- Laboratoire de Cristallographie et RMN biologiques, Université Paris Descartes, CNRS UMR 8015, 75006 Paris Cedex, France
| | - Dona Sleiman
- Laboratoire de Cristallographie et RMN biologiques, Université Paris Descartes, CNRS UMR 8015, 75006 Paris Cedex, France
| | - Nelly Morellet
- Centre de Recherches de Gif, Institut de Chimie des Substances Naturelles, CNRS UPR 2301, 91190 Gif sur Yvette Cedex, France
| | - Ewen Lescop
- Centre de Recherches de Gif, Institut de Chimie des Substances Naturelles, CNRS UPR 2301, 91190 Gif sur Yvette Cedex, France
| | - Ouerdia Maskri
- LBPA, ENS de Cachan, CNRS, Université Paris-Saclay, 94235 Cachan Cedex, France
| | - Brigitte René
- LBPA, ENS de Cachan, CNRS, Université Paris-Saclay, 94235 Cachan Cedex, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, CNRS UMR 7213, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch Cedex, France
| | - Philippe Fossé
- LBPA, ENS de Cachan, CNRS, Université Paris-Saclay, 94235 Cachan Cedex, France
| | - Olivier Mauffret
- LBPA, ENS de Cachan, CNRS, Université Paris-Saclay, 94235 Cachan Cedex, France
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10
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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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11
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Wu H, Wang W, Naiyer N, Fichtenbaum E, Qualley DF, McCauley MJ, Gorelick RJ, Rouzina I, Musier-Forsyth K, Williams MC. Single aromatic residue location alters nucleic acid binding and chaperone function of FIV nucleocapsid protein. Virus Res 2014; 193:39-51. [PMID: 24915282 PMCID: PMC4252577 DOI: 10.1016/j.virusres.2014.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 05/28/2014] [Accepted: 06/02/2014] [Indexed: 10/25/2022]
Abstract
Feline immunodeficiency virus (FIV) is a retrovirus that infects domestic cats, and is an excellent animal model for human immunodeficiency virus type 1 (HIV-1) pathogenesis. The nucleocapsid (NC) protein is critical for replication in both retroviruses. FIV NC has several structural features that differ from HIV-1 NC. While both NC proteins have a single conserved aromatic residue in each of the two zinc fingers, the aromatic residue on the second finger of FIV NC is located on the opposite C-terminal side relative to its location in HIV-1 NC. In addition, whereas HIV-1 NC has a highly charged cationic N-terminal tail and a relatively short C-terminal extension, the opposite is true for FIV NC. To probe the impact of these differences on the nucleic acid (NA) binding and chaperone properties of FIV NC, we carried out ensemble and single-molecule assays with wild-type (WT) and mutant proteins. The ensemble studies show that FIV NC binding to DNA is strongly electrostatic, with a higher effective charge than that observed for HIV-1 NC. The C-terminal basic domain contributes significantly to the NA binding capability of FIV NC. In addition, the non-electrostatic component of DNA binding is much weaker for FIV NC than for HIV-1 NC. Mutation of both aromatic residues in the zinc fingers to Ala (F12A/W44A) further increases the effective charge of FIV NC and reduces its non-electrostatic binding affinity. Interestingly, switching the location of the C-terminal aromatic residue to mimic the HIV-1 NC sequence (N31W/W44A) reduces the effective charge of FIV NC and increases its non-electrostatic binding affinity to values similar to HIV-1 NC. Consistent with the results of these ensemble studies, single-molecule DNA stretching studies show that while WT FIV NC has reduced stacking capability relative to HIV-1 NC, the aromatic switch mutant recovers the ability to intercalate between the DNA bases. Our results demonstrate that altering the position of a single aromatic residue switches the binding mode of FIV NC from primarily electrostatic binding to more non-electrostatic binding, conferring upon it NA interaction properties comparable to that of HIV-1 NC.
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Affiliation(s)
- Hao Wu
- Northeastern University, Department of Physics, Boston, MA 02115, USA
| | - Wei Wang
- The Ohio State University, Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, Columbus, OH 43210, USA
| | - Nada Naiyer
- The Ohio State University, Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, Columbus, OH 43210, USA
| | - Eric Fichtenbaum
- The Ohio State University, Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, Columbus, OH 43210, USA
| | - Dominic F Qualley
- The Ohio State University, Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, Columbus, OH 43210, USA
| | - Micah J McCauley
- Northeastern University, Department of Physics, 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, 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, and Center for RNA Biology, Columbus, OH 43210, USA.
| | - Mark C Williams
- Northeastern University, Department of Physics, Boston, MA 02115, USA.
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12
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Blond A, Ennifar E, Tisné C, Micouin L. The design of RNA binders: targeting the HIV replication cycle as a case study. ChemMedChem 2014; 9:1982-96. [PMID: 25100137 DOI: 10.1002/cmdc.201402259] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Indexed: 01/08/2023]
Abstract
The human immunodeficiency virus 1 (HIV-1) replication cycle is finely tuned with many important steps involving RNA-RNA or protein-RNA interactions, all of them being potential targets for the development of new antiviral compounds. This cycle can also be considered as a good benchmark for the evaluation of early-stage strategies aiming at designing drugs that bind to RNA, with the possibility to correlate in vitro activities with antiviral properties. In this review, we highlight different approaches developed to interfere with four important steps of the HIV-1 replication cycle: the early stage of reverse transcription, the transactivation of viral transcription, the nuclear export of partially spliced transcripts and the dimerization step.
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Affiliation(s)
- Aurélie Blond
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601, CNRS, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 Rue des Saints Pères, 75006 Paris (France)
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13
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Sleiman D, Bernacchi S, Xavier Guerrero S, Brachet F, Larue V, Paillart JC, Tisne C. Characterization of RNA binding and chaperoning activities of HIV-1 Vif protein. Importance of the C-terminal unstructured tail. RNA Biol 2014; 11:906-20. [PMID: 25144404 DOI: 10.4161/rna.29546] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The viral infectivity factor (Vif) is essential for the productive infection and dissemination of HIV-1 in non-permissive cells, containing the cellular anti-HIV defense cytosine deaminases APOBEC3 (A3G and A3F). Vif neutralizes the antiviral activities of the APOBEC3G/F by diverse mechanisms including their degradation through the ubiquitin/proteasome pathway and their translational inhibition. In addition, Vif appears to be an active partner of the late steps of viral replication by interacting with Pr55(Gag), reverse transcriptase and genomic RNA. Here, we expressed and purified full-length and truncated Vif proteins, and analyzed their RNA binding and chaperone properties. First, we showed by CD and NMR spectroscopies that the N-terminal domain of Vif is highly structured in solution, whereas the C-terminal domain remains mainly unfolded. Both domains exhibited substantial RNA binding capacities with dissociation constants in the nanomolar range, whereas the basic unfolded C-terminal domain of Vif was responsible in part for its RNA chaperone activity. Second, we showed by NMR chemical shift mapping that Vif and NCp7 share the same binding sites on tRNA(Lys) 3, the primer of HIV-1 reverse transcriptase. Finally, our results indicate that Vif has potent RNA chaperone activity and provide direct evidence for an important role of the unstructured C-terminal domain of Vif in this capacity.
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14
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Zargarian L, Tisné C, Barraud P, Xu X, Morellet N, René B, Mély Y, Fossé P, Mauffret O. Dynamics of linker residues modulate the nucleic acid binding properties of the HIV-1 nucleocapsid protein zinc fingers. PLoS One 2014; 9:e102150. [PMID: 25029439 PMCID: PMC4100767 DOI: 10.1371/journal.pone.0102150] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 06/16/2014] [Indexed: 01/20/2023] Open
Abstract
The HIV-1 nucleocapsid protein (NC) is a small basic protein containing two zinc fingers (ZF) separated by a short linker. It is involved in several steps of the replication cycle and acts as a nucleic acid chaperone protein in facilitating nucleic acid strand transfers occurring during reverse transcription. Recent analysis of three-dimensional structures of NC-nucleic acids complexes established a new property: the unpaired guanines targeted by NC are more often inserted in the C-terminal zinc finger (ZF2) than in the N-terminal zinc finger (ZF1). Although previous NMR dynamic studies were performed with NC, the dynamic behavior of the linker residues connecting the two ZF domains remains unclear. This prompted us to investigate the dynamic behavior of the linker residues. Here, we collected 15N NMR relaxation data and used for the first time data at several fields to probe the protein dynamics. The analysis at two fields allows us to detect a slow motion occurring between the two domains around a hinge located in the linker at the G35 position. However, the amplitude of motion appears limited in our conditions. In addition, we showed that the neighboring linker residues R29, A30, P31, R32, K33 displayed restricted motion and numerous contacts with residues of ZF1. Our results are fully consistent with a model in which the ZF1-linker contacts prevent the ZF1 domain to interact with unpaired guanines, whereas the ZF2 domain is more accessible and competent to interact with unpaired guanines. In contrast, ZF1 with its large hydrophobic plateau is able to destabilize the double-stranded regions adjacent to the guanines bound by ZF2. The linker residues and the internal dynamics of NC regulate therefore the different functions of the two zinc fingers that are required for an optimal chaperone activity.
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Affiliation(s)
- Loussiné Zargarian
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8113, Cachan, France
| | - Carine Tisné
- Laboratoire de Cristallographie et RMN Biologiques, Université Paris Descartes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8015, Paris, France
| | - Pierre Barraud
- Laboratoire de Cristallographie et RMN Biologiques, Université Paris Descartes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8015, Paris, France
| | - Xiaoqian Xu
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8113, Cachan, France
- Department of Life Sciences, East China Normal University, Shanghai, People's Republic of China
| | - Nelly Morellet
- Centre de Recherches de Gif, Institut de Chimie des Substances Naturelles, Centre National de la Recherche Scientifique, Gif sur Yvette, France
| | - Brigitte René
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8113, Cachan, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7213, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Philippe Fossé
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8113, Cachan, France
| | - Olivier Mauffret
- Laboratoire de Biologie et Pharmacologie Appliquée, Ecole Normale Supérieure de Cachan, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8113, Cachan, France
- * E-mail:
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15
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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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16
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Ponchon L, Catala M, Seijo B, El Khouri M, Dardel F, Nonin-Lecomte S, Tisné C. Co-expression of RNA-protein complexes in Escherichia coli and applications to RNA biology. Nucleic Acids Res 2013; 41:e150. [PMID: 23804766 PMCID: PMC3753655 DOI: 10.1093/nar/gkt576] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
RNA has emerged as a major player in many cellular processes. Understanding these processes at the molecular level requires homogeneous RNA samples for structural, biochemical and pharmacological studies. We previously devised a generic approach that allows efficient in vivo expression of recombinant RNA in Escherichia coli. In this work, we have extended this method to RNA/protein co-expression. We have engineered several plasmids that allow overexpression of RNA–protein complexes in E. coli. We have investigated the potential of these tools in many applications, including the production of nuclease-sensitive RNAs encapsulated in viral protein pseudo-particles, the co-production of non-coding RNAs with chaperone proteins, the incorporation of a post-transcriptional RNA modification by co-production with the appropriate modifying enzyme and finally the production and purification of an RNA–His-tagged protein complex by nickel affinity chromatography. We show that this last application easily provides pure material for crystallographic studies. The new tools we report will pave the way to large-scale structural and molecular investigations of RNA function and interactions with proteins.
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Affiliation(s)
- Luc Ponchon
- CNRS, UMR 8015, Laboratoire de Cristallographie et RMN biologiques, 4 avenue de l'Observatoire, 75006 Paris, France and Université Paris Descartes, Sorbonne Paris Cité, UMR 8015, Laboratoire de Cristallographie et RMN biologiques, 4 avenue de l'Observatoire, 75006 Paris, France
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17
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Sleiman D, Barraud P, Brachet F, Tisne C. The Interaction between tRNA(Lys) 3 and the primer activation signal deciphered by NMR spectroscopy. PLoS One 2013; 8:e64700. [PMID: 23762248 PMCID: PMC3675109 DOI: 10.1371/journal.pone.0064700] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 04/17/2013] [Indexed: 11/23/2022] Open
Abstract
The initiation of reverse transcription of the human immunodeficiency virus type 1 (HIV-1) requires the opening of the three-dimensional structure of the primer tRNALys3 for its annealing to the viral RNA at the primer binding site (PBS). Despite the fact that the result of this rearrangement is thermodynamically more stable, there is a high-energy barrier that requires the chaperoning activity of the viral nucleocapsid protein. In addition to the nucleotide complementarity to the PBS, several regions of tRNALys3 have been described as interacting with the viral genomic RNA. Among these sequences, a sequence of the viral genome called PAS for “primer activation signal” was proposed to interact with the T-arm of tRNALys3, this interaction stimulating the initiation of reverse transcription. In this report, we investigate the formation of this additional interaction with NMR spectroscopy, using a simple system composed of the primer tRNALys3, the 18 nucleotides of the PBS, the PAS (8 nucleotides) encompassed or not in a hairpin structure, and the nucleocapsid protein. Our NMR study provides molecular evidence of the existence of this interaction and highlights the role of the nucleocapsid protein in promoting this additional RNA-RNA annealing. This study presents the first direct observation at a single base-pair resolution of the PAS/anti-PAS association, which has been proposed to be involved in the chronological regulation of the reverse transcription.
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Affiliation(s)
- Dona Sleiman
- Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, Paris Sorbonne Cité, Paris, France
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18
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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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19
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Moumné R, Catala M, Larue V, Micouin L, Tisné C. Fragment-based design of small RNA binders: Promising developments and contribution of NMR. Biochimie 2012; 94:1607-19. [DOI: 10.1016/j.biochi.2012.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 02/01/2012] [Indexed: 02/06/2023]
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20
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Godet J, Boudier C, Humbert N, Ivanyi-Nagy R, Darlix JL, Mély Y. Comparative nucleic acid chaperone properties of the nucleocapsid protein NCp7 and Tat protein of HIV-1. Virus Res 2012; 169:349-60. [PMID: 22743066 PMCID: PMC7114403 DOI: 10.1016/j.virusres.2012.06.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 10/28/2022]
Abstract
RNA chaperones are proteins able to rearrange nucleic acid structures towards their most stable conformations. In retroviruses, the reverse transcription of the viral RNA requires multiple and complex nucleic acid rearrangements that need to be chaperoned. HIV-1 has evolved different viral-encoded proteins with chaperone activity, notably Tat and the well described nucleocapsid protein NCp7. We propose here an overview of the recent reports that examine and compare the nucleic acid chaperone properties of Tat and NCp7 during reverse transcription to illustrate the variety of mechanisms of action of the nucleic acid chaperone proteins.
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Affiliation(s)
- Julien Godet
- Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, UMR 7213 CNRS, Université de Strasbourg, 67401 Illkirch, France
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21
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Nucleocapsid protein annealing of a primer-template enhances (+)-strand DNA synthesis and fidelity by HIV-1 reverse transcriptase. J Mol Biol 2011; 415:866-80. [PMID: 22210155 DOI: 10.1016/j.jmb.2011.12.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 12/09/2011] [Accepted: 12/16/2011] [Indexed: 11/22/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) requires reverse transcriptase (RT) and HIV-1 nucleocapsid protein (NCp7) for proper viral replication. HIV-1 NCp7 has been shown to enhance various steps in reverse transcription including tRNA initiation and strand transfer, which may be mediated through interactions with RT as well as RNA and DNA oligonucleotides. With the use of DNA oligonucleotides, we have examined the interaction of NCp7 with RT and the kinetics of reverse transcription during (+)-strand synthesis with an NCp7-facilitated annealed primer-template. Through the use of a pre-steady-state kinetics approach, the NCp7-annealed primer-template has a substantial increase (3- to 7-fold) in the rate of incorporation (k(pol)) by RT as compared to heat-annealed primer-template with single-nucleotide incorporation. There was also a 2-fold increase in the binding affinity constant (K(d)) of the nucleotide. These differences in k(pol) and K(d) were not through direct interactions between HIV-1 RT and NCp7. When extension by RT was examined, the data suggest that the NCp7-annealed primer-template facilitates the formation of a longer product more quickly compared to the heat-annealed primer-template. This enhancement in rate is mediated through interactions with NCp7's zinc fingers and N-terminal domain and nucleic acids. The NCp7-annealed primer-template also enhances the fidelity of RT (3-fold) by slowing the rate of incorporation of an incorrect nucleotide. Taken together, this study elucidates a new role of NCp7 by facilitating DNA-directed DNA synthesis during reverse transcription by HIV-1 RT that may translate into enhanced viral fitness and offers an avenue to exploit for targeted therapeutic intervention against HIV.
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22
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Graham WD, Barley-Maloney L, Stark CJ, Kaur A, Stolyarchuk K, Sproat B, Leszczynska G, Malkiewicz A, Safwat N, Mucha P, Guenther R, Agris PF. Functional recognition of the modified human tRNALys3(UUU) anticodon domain by HIV's nucleocapsid protein and a peptide mimic. J Mol Biol 2011; 410:698-715. [PMID: 21762809 PMCID: PMC3662833 DOI: 10.1016/j.jmb.2011.04.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 04/06/2011] [Accepted: 04/11/2011] [Indexed: 11/27/2022]
Abstract
The HIV-1 nucleocapsid protein, NCp7, facilitates the use of human tRNA(Lys3)(UUU) as the primer for reverse transcription. NCp7 also remodels the htRNA's amino acid accepting stem and anticodon domains in preparation for their being annealed to the viral genome. To understand the possible influence of the htRNA's unique composition of post-transcriptional modifications on NCp7 recognition of htRNA(Lys3)(UUU), the protein's binding and functional remodeling of the human anticodon stem and loop domain (hASL(Lys3)) were studied. NCp7 bound the hASL(Lys3)(UUU) modified with 5-methoxycarbonylmethyl-2-thiouridine at position-34 (mcm(5)s(2)U(34)) and 2-methylthio-N(6)-threonylcarbamoyladenosine at position-37 (ms(2)t(6)A(37)) with a considerably higher affinity than the unmodified hASL(Lys3)(UUU) (K(d)=0.28±0.03 and 2.30±0.62 μM, respectively). NCp7 denatured the structure of the hASL(Lys3)(UUU)-mcm(5)s(2)U(34);ms(2)t(6)A(37);Ψ(39) more effectively than that of the unmodified hASL(Lys3)(UUU). Two 15 amino acid peptides selected from phage display libraries demonstrated a high affinity (average K(d)=0.55±0.10 μM) and specificity for the ASL(Lys3)(UUU)-mcm(5)s(2)U(34);ms(2)t(6)A(37) comparable to that of NCp7. The peptides recognized a t(6)A(37)-modified ASL with an affinity (K(d)=0.60±0.09 μM) comparable to that for hASL(Lys3)(UUU)-mcm(5)s(2)U(34);ms(2)t(6)A(37), indicating a preference for the t(6)A(37) modification. Significantly, one of the peptides was capable of relaxing the hASL(Lys3)(UUU)-mcm(5)s(2)U(34);ms(2)t(6)A(37);Ψ(39) structure in a manner similar to that of NCp7, and therefore could be used to further study protein recognition of RNA modifications. The post-transcriptional modifications of htRNA(Lys3)(UUU) have been found to be important determinants of NCp7's recognition prior to the tRNA(Lys3)(UUU) being annealed to the viral genome as the primer of reverse transcription.
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Affiliation(s)
- William D. Graham
- Molecular and Structural Biochemistry, North Carolina State University, Raleigh NC 27695, USA
| | - Lise Barley-Maloney
- Molecular and Structural Biochemistry, North Carolina State University, Raleigh NC 27695, USA
| | - Caren J. Stark
- Te RNA Institute, Biological Sciences, University at Albany, Albany, NY 12222, USA
| | - Amarpreet Kaur
- Molecular and Structural Biochemistry, North Carolina State University, Raleigh NC 27695, USA
| | - Khrystyna Stolyarchuk
- Molecular and Structural Biochemistry, North Carolina State University, Raleigh NC 27695, USA
| | - Brian Sproat
- Integrated DNA Technologies BVBA, Interleuvenlaan 12A, B-3001 Leuven, Belgium
| | - Grazyna Leszczynska
- Institute of Organic Chemistry, Technical University, Żeromskiego 116, 90-924, ŁódŸ, Poland
| | - Andrzej Malkiewicz
- Institute of Organic Chemistry, Technical University, Żeromskiego 116, 90-924, ŁódŸ, Poland
| | - Nedal Safwat
- Molecular and Structural Biochemistry, North Carolina State University, Raleigh NC 27695, USA
| | - Piotr Mucha
- Department of Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk, Poland
| | - Richard Guenther
- Molecular and Structural Biochemistry, North Carolina State University, Raleigh NC 27695, USA
| | - Paul F. Agris
- Te RNA Institute, Biological Sciences, University at Albany, Albany, NY 12222, USA
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23
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Hao ZX, Feng R, Wang ED, Zhu G. 1H, 15N chemical shift assignments of the imino groups in the base pairs of Escherichia coli tRNA(Leu) (CAG). BIOMOLECULAR NMR ASSIGNMENTS 2011; 5:71-74. [PMID: 20931304 DOI: 10.1007/s12104-010-9270-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 09/22/2010] [Indexed: 05/30/2023]
Abstract
tRNA molecules are the adaptors in ribosome-based protein biosynthesis and are stabilized by Mg(2+). However, the detailed mechanism for the Mg(2+) mediated stability is not fully understood. To study the effects of Mg(2+) on conformational flexibility of Escherichia coli tRNA(Leu) (CAG) at millisecond timescale, we applied NMR spectroscopic approach to measure proton exchange rates of imino groups in the presence of different concentration of Mg(2+) and correlated them with the corresponding aminoacylation activity of tRNA(Leu). Here, we report the first part of the above mentioned study, the (1)H, (15)N chemical shift assignments of the imino groups in all base pairs of Escherichia coli tRNA(Leu) (CAG) based on 2D (1)H-(15)N TROSY, 2D NOESY and 3D NOESY-HMQC experiments. This work laid the foundation for the NMR study of tRNA(Leu) (BMRB deposits with accession number 17078).
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Affiliation(s)
- Zhan-Xi Hao
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Graduate School of the Chinese Academy of Sciences, Shanghai, China
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24
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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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25
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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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Tompa P, Kovacs D. Intrinsically disordered chaperones in plants and animalsThis paper is one of a selection of papers published in this special issue entitled “Canadian Society of Biochemistry, Molecular & Cellular Biology 52nd Annual Meeting — Protein Folding: Principles and Diseases” and has undergone the Journal's usual peer review process. Biochem Cell Biol 2010; 88:167-74. [DOI: 10.1139/o09-163] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) are widespread in eukaryotes and fulfill important functions associated with signaling and regulation. Recent evidence points to a special and thus largely disrespected functional capacity of IDPs—that they can assist the folding of other proteins and prevent their aggregation, i.e., that they can act as chaperones. In this paper, we survey current information available on this phenomenon, with particular focus on (i) the structure and function of IDPs in general, (ii) disordered chaperones in plants, (iii) disordered chaperones in other organisms spanning from insects to mammals, (iv) the possible mechanisms of action of disordered chaperones, and (v) the possibility of two-faced (Janus) chaperone activity of disordered chaperones, which can assist the folding of both RNA and protein substrates. The evidence is most conclusive in the case of plant stress proteins, such as late embryogenesis abundant (LEA) proteins or dehydrins. We will show that the cellular function of LEA proteins in mitigating the damage caused by stress is clear; nevertheless, experiments carried out in vivo must be extended and the molecular mechanism of the action of IDP chaperones also requires clarification. Using these details, we chart out how far the field has progressed only to emphasize the long road ahead before chaperone function can be firmly established as part of the physiological mechanistic arsenal of the emerging group of IDPs.
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Affiliation(s)
- Peter Tompa
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Karolina ut 29, H-1113 Budapest, Hungary
| | - Denes Kovacs
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, Karolina ut 29, H-1113 Budapest, Hungary
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27
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Isel C, Ehresmann C, Marquet R. Initiation of HIV Reverse Transcription. Viruses 2010; 2:213-243. [PMID: 21994608 PMCID: PMC3185550 DOI: 10.3390/v2010213] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 01/08/2010] [Accepted: 01/13/2010] [Indexed: 12/01/2022] Open
Abstract
Reverse transcription of retroviral genomes into double stranded DNA is a key event for viral replication. The very first stage of HIV reverse transcription, the initiation step, involves viral and cellular partners that are selectively packaged into the viral particle, leading to an RNA/protein complex with very specific structural and functional features, some of which being, in the case of HIV-1, linked to particular isolates. Recent understanding of the tight spatio-temporal regulation of reverse transcription and its importance for viral infectivity further points toward reverse transcription and potentially its initiation step as an important drug target.
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Affiliation(s)
- Catherine Isel
- Authors to whom correspondence should be addressed; E-Mail: ; Tel.: +33-388-417-040; Fax: +33-388-602-218 (C.I.); E-Mail: ; Tel.: +33-388-417-054; Fax: +33-388-602-218 (R.M.)
| | | | - Roland Marquet
- Authors to whom correspondence should be addressed; E-Mail: ; Tel.: +33-388-417-040; Fax: +33-388-602-218 (C.I.); E-Mail: ; Tel.: +33-388-417-054; Fax: +33-388-602-218 (R.M.)
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28
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Alexander RW, Eargle J, Luthey-Schulten Z. Experimental and computational determination of tRNA dynamics. FEBS Lett 2009; 584:376-86. [PMID: 19932098 DOI: 10.1016/j.febslet.2009.11.061] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 11/14/2009] [Accepted: 11/16/2009] [Indexed: 10/20/2022]
Abstract
As the molecular representation of the genetic code, tRNA plays a central role in the translational machinery where it interacts with several proteins and other RNAs during the course of protein synthesis. These interactions exploit the dynamic flexibility of tRNA. In this minireview, we discuss the effects of modified bases, ions, and proteins on tRNA structure and dynamics and the challenges of observing its motions over the cycle of translation.
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Affiliation(s)
- Rebecca W Alexander
- Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109-7486, United States.
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29
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Saadatmand J, Niu M, Kleiman L, Guo F. The contribution of the primer activation signal to differences between Gag- and NCp7-facilitated tRNA(Lys3) annealing in HIV-1. Virology 2009; 391:334-41. [PMID: 19616817 DOI: 10.1016/j.virol.2009.06.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 06/15/2009] [Accepted: 06/22/2009] [Indexed: 10/20/2022]
Abstract
During tRNA(Lys3) annealing in HIV-1, tRNA(Lys3) binds to both the primer binding site (PBS) and to an 8 nucleotide base-paired sequence upstream of the PBS known as the primer activation signal (PAS). In protease-negative (Pr(-)) HIV-1, the amount of tRNA(Lys3) annealed by Gag is 35% less than that annealed by mature nucleocapsid (NCp7) in protease-positive (Pr(+)) virions. Gag-annealed tRNA(Lys3) also has a reduced ability to initiate reverse transcription, and binds less tightly to viral RNA than NCp7-annealed tRNA(Lys3). Pr(-) virions containing a constitutively single-stranded PAS (2R mutant), show a significant increase in the ability to initiate reverse transcription with little change in the amount of tRNA(Lys3) annealed. However, the 2R mutant does not achieve levels of RT initiation achieved in Pr(+) virions, and tRNA(Lys3) binding to viral RNA remains weak. Wild type levels of initiation and tRNA(Lys3) binding to viral RNA can only be recovered by transient exposure of Pr(-) or Pr(-)2R viral RNA to NCp7. This suggests that in addition to facilitating annealing of tRNA(Lys3) to the PBS and possible denaturation of the PAS, other functions of NCp7 involved in annealing are required. The effect of an inactive protease and/or the 2R mutation upon tRNA(Lys3) annealing and initiation are also observed when the tRNA(Lys3) is annealed in vitro to wild type or mutant viral RNA using either NCp7 or GagDeltap6, indicating a direct effect of the 2R mutation upon tRNA(Lys3) annealing.
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Affiliation(s)
- Jenan Saadatmand
- Lady Davis Institute for Medical Research and McGill AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada H3T 1E2
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30
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Chung F, Tisné C, Lecourt T, Seijo B, Dardel F, Micouin L. Design of tRNALys3Ligands: Fragment Evolution and Linker Selection Guided by NMR Spectroscopy. Chemistry 2009; 15:7109-16. [DOI: 10.1002/chem.200802451] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Roles of Gag and NCp7 in facilitating tRNA(Lys)(3) Annealing to viral RNA in human immunodeficiency virus type 1. J Virol 2009; 83:8099-107. [PMID: 19494012 DOI: 10.1128/jvi.00488-09] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In protease-negative human immunodeficiency virus type 1 (HIV-1) [Pr(-)], the amount of tRNA(3)(Lys) annealed by Gag is modestly reduced ( approximately 25%) compared to that annealed by mature nucleocapsid (NCp7) in protease-positive HIV-1 [Pr(+)]. However, the tRNA(3)(Lys) annealed by Gag also has a strongly reduced ability to initiate reverse transcription and binds less tightly to viral RNA. Both in vivo and in vitro, APOBEC3G (A3G) inhibits tRNA(3)(Lys) annealing facilitated by NCp7 but not annealing facilitated by Gag. While transient exposure of Pr(-) viral RNA to NCp7 in vitro returns the quality and quantity of tRNA(3)(Lys) annealing to Pr(+) levels, the presence of A3G both prevents this rescue and creates a further reduction in tRNA(3)(Lys) annealing. Since A3G inhibition of NCp7-facilitated tRNA(3)(Lys) annealing in vitro requires the presence of A3G during the annealing process, these results suggest that in Pr(+) viruses NCp7 can displace Gag-annealed tRNA(3)(Lys) and re-anneal it to viral RNA, the re-annealing step being subject to A3G inhibition. This supports the possibility that the initial annealing of tRNA(3)(Lys) in wild-type, Pr(+) virus may be by Gag and not by NCp7, perhaps offering the advantage of Gag's preference for binding to RNA stem-loops in the 5' region of viral RNA near the tRNA(3)(Lys) annealing region.
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32
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Disorder-to-order conformational transitions in protein structure and its relationship to disease. Mol Cell Biochem 2009; 330:105-20. [PMID: 19357935 DOI: 10.1007/s11010-009-0105-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Accepted: 03/30/2009] [Indexed: 01/22/2023]
Abstract
Function in proteins largely depends on the acquisition of specific structures through folding at physiological time scales. Under both equilibrium and non-equilibrium states, proteins develop partially structured molecules that being intermediates in the process, usually resemble the structure of the fully folded protein. These intermediates, known as molten globules, present the faculty of adopting a large variety of conformations mainly supported by changes in their side chains. Taking into account that the mechanism to obtain a fully packed structure is considered more difficult energetically than forming partially "disordered" folding intermediates, evolution might have conferred upon an important number of proteins the capability to first partially fold and-depending on the presence of specific partner ligands-switch on disorder-to-order transitions to adopt a highly ordered well-folded state and reach the lowest energy conformation possible. Disorder in this context can represent segments of proteins or complete proteins that might exist in the native state. Moreover, because this type of disorder-to-order transition in proteins has been found to be reversible, it has been frequently associated with important signaling events in the cell. Due to the central role of this phenomenon in cell biology, protein misfolding and aberrant disorder-to-order transitions have been at present associated with an important number of diseases.
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33
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Bilbille Y, Vendeix FAP, Guenther R, Malkiewicz A, Ariza X, Vilarrasa J, Agris PF. The structure of the human tRNALys3 anticodon bound to the HIV genome is stabilized by modified nucleosides and adjacent mismatch base pairs. Nucleic Acids Res 2009; 37:3342-53. [PMID: 19324888 PMCID: PMC2691828 DOI: 10.1093/nar/gkp187] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Replication of human immunodeficiency virus (HIV) requires base pairing of the reverse transcriptase primer, human tRNALys3, to the viral RNA. Although the major complementary base pairing occurs between the HIV primer binding sequence (PBS) and the tRNA's 3′-terminus, an important discriminatory, secondary contact occurs between the viral A-rich Loop I, 5′-adjacent to the PBS, and the modified, U-rich anticodon domain of tRNALys3. The importance of individual and combined anticodon modifications to the tRNA/HIV-1 Loop I RNA's interaction was determined. The thermal stabilities of variously modified tRNA anticodon region sequences bound to the Loop I of viral sub(sero)types G and B were analyzed and the structure of one duplex containing two modified nucleosides was determined using NMR spectroscopy and restrained molecular dynamics. The modifications 2-thiouridine, s2U34, and pseudouridine, Ψ39, appreciably stabilized the interaction of the anticodon region with the viral subtype G and B RNAs. The structure of the duplex results in two coaxially stacked A-form RNA stems separated by two mismatched base pairs, U162•Ψ39 and G163•A38, that maintained a reasonable A-form helix diameter. The tRNA's s2U34 stabilized the interaction between the A-rich HIV Loop I sequence and the U-rich anticodon, whereas the tRNA's Ψ39 stabilized the adjacent mismatched pairs.
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Affiliation(s)
- Yann Bilbille
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622, USA
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34
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Zhang Z, Xi X, Scholes CP, Karim CB. Rotational dynamics of HIV-1 nucleocapsid protein NCp7 as probed by a spin label attached by peptide synthesis. Biopolymers 2008; 89:1125-35. [PMID: 18690667 PMCID: PMC3587331 DOI: 10.1002/bip.21064] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
2,2,6,6-Tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid (TOAC) spin label was attached at the N-terminal position to interrogate the dynamics of the HIV-1 nucleocapsid Zn-finger protein, NCp7. NCp7 is a 6.4-kDa 55-mer critical to the recognition, packaging, and efficient reverse transcription of viral RNA that has stem-loop structures, such as the RNA stem-loop 3 used in this work. The NCp7, made by solid-phase peptide synthesis with TOAC incorporated into the alpha-carbon backbone at the N-terminal "0" position, showed analytical purity and biological activity. Electron Paramagnetic Resonance (EPR) spectra of the N-terminal TOAC indicated rapid temperature-sensitive motion of the probe (< or =0.33 ns correlation time) on the flexible N-terminal segment. This N-terminal TOAC-NCp7 reported a RNA-NCp7 interaction at a 1:1 ratio of NCp7 to RNA, which caused the tumbling time to be slowed from about 0.3 ns to about 0.5 ns. NCp7 is a largely disordered protein that adapts to its RNA targets. However, as shown by circular dichroism, > or =90% trifluoroethanol [(TFE), an alpha-helix enhancer] caused the TOAC-NCp7 without zinc in its fingers to change to a fully helical conformation, while the TOAC spin label was concurrently reporting a tumbling time of well over a nanosecond, as the N-terminal TOAC became inflexibly enfolded. Even with TFE present, the existence of intact Zn-finger regions in NCp7 prevented complete formation of helical structure, as shown by circular dichroism, and decreased the N-terminal TOAC tumbling time, as shown by EPR. This study demonstrated TOAC at the N-terminal of NCp7 to be a reporter for the considerable conformational lability of NCp7. (
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Affiliation(s)
- Zhiwen Zhang
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Xiangmei Xi
- Department of Chemistry, University at Albany - SUNY, Albany, NY 12222
| | | | - Christine B. Karim
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
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35
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Bakkali H, Marie C, Ly A, Thobie-Gautier C, Graton J, Pipelier M, Sengmany S, Léonel E, Nédélec JY, Evain M, Dubreuil D. Functionalized 2,5-Dipyridinylpyrroles by Electrochemical Reduction of 3,6-Dipyridinylpyridazine Precursors. European J Org Chem 2008. [DOI: 10.1002/ejoc.200701115] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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36
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Barraud P, Dardel F, Tisné C. Optimizing HSQC experiment for the observation of exchange broadened signals in RNA–protein complexes. CR CHIM 2008. [DOI: 10.1016/j.crci.2007.06.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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37
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Abbink TEM, Berkhout B. HIV-1 reverse transcription initiation: a potential target for novel antivirals? Virus Res 2008; 134:4-18. [PMID: 18255184 DOI: 10.1016/j.virusres.2007.12.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Revised: 12/14/2007] [Accepted: 12/14/2007] [Indexed: 11/19/2022]
Abstract
Reverse transcription is an essential step in the retroviral life cycle, as it converts the genomic RNA into DNA. In this review, we describe recent developments concerning the initiation step of this complex, multi-step reaction. During initiation of reverse transcription, a cellular tRNA primer is placed onto a complementary sequence in the viral genome, called the primer binding site or PBS. The viral enzyme reverse transcriptase (RT) recognizes this RNA-RNA complex, and catalyzes the extension of the 3' end of the tRNA primer, with the viral RNA (vRNA) acting as template. The initiation step is highly specific and most retroviruses are restricted to the use of the cognate, self-tRNA primer. Human immunodeficiency virus type 1 (HIV-1) uses the cellular tRNA(Lys,3) molecule as primer for reverse transcription. No spontaneous switches in tRNA usage by HIV-1 or other retroviruses have been described and attempts to change the identity of the tRNA primer were unsuccessful in the past. These observations indicate that the virus strongly prefers the self-primer, suggesting that a very specific mechanism for primer selection must exist. Indeed, tRNA primers are selectively packaged into virus particles, are specifically recognized by RT and are placed onto the viral RNA genome via base pairing to the PBS and other sequence motifs, thus rendering a specific initiation complex. Analysis of this critical step in the viral life cycle may result in the discovery of novel antiviral drugs in the battle against HIV/AIDS.
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Affiliation(s)
- Truus E M Abbink
- Laboratory of Experimental Virology, Department of Medical Microbiology, Centre for Infection and Immunity Amsterdam (CINIMA), Academic Medical Centre of the University of Amsterdam, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands
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38
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Chung F, Tisné C, Lecourt T, Dardel F, Micouin L. NMR-guided fragment-based approach for the design of tRNA(Lys3) ligands. Angew Chem Int Ed Engl 2007; 46:4489-91. [PMID: 17486554 DOI: 10.1002/anie.200605201] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Florence Chung
- Chimie Thérapeutique, Université Paris Descartes, CNRS, 4 avenue de l'Observatoire, 75006 Paris, France
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39
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Abbink TEM, Berkhout B. HIV-1 reverse transcription: close encounters between the viral genome and a cellular tRNA. ADVANCES IN PHARMACOLOGY 2007; 55:99-135. [PMID: 17586313 DOI: 10.1016/s1054-3589(07)55003-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2023]
Affiliation(s)
- Truus E M Abbink
- Laboratory of Experimental Virology, Department of Medical Microbiology, Center for Infection and Immunity Amsterdam, Academic Medical Center of the University of Amsterdam, Meibergdreef 15, Amsterdam, The Netherlands
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40
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Chung F, Tisné C, Lecourt T, Dardel F, Micouin L. NMR-Guided Fragment-Based Approach for the Design of tRNALys3 Ligands. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200605201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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41
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Darlix JL, Garrido JL, Morellet N, Mély Y, de Rocquigny H. Properties, functions, and drug targeting of the multifunctional nucleocapsid protein of the human immunodeficiency virus. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2007; 55:299-346. [PMID: 17586319 DOI: 10.1016/s1054-3589(07)55009-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Jean-Luc Darlix
- LaboRetro, Unité INSERM de Virologie Humaine, IFR128, ENS Sciences de Lyon 46 allée d'Italie, Lyon, France
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42
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Cruceanu M, Urbaneja MA, Hixson CV, Johnson DG, Datta SA, Fivash MJ, Stephen AG, Fisher RJ, Gorelick RJ, Casas-Finet JR, Rein A, Rouzina I, Williams MC. Nucleic acid binding and chaperone properties of HIV-1 Gag and nucleocapsid proteins. Nucleic Acids Res 2006; 34:593-605. [PMID: 16449201 PMCID: PMC1356529 DOI: 10.1093/nar/gkj458] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The Gag polyprotein of HIV-1 is essential for retroviral replication and packaging. The nucleocapsid (NC) protein is the primary region for the interaction of Gag with nucleic acids. In this study, we examine the interactions of Gag and its NC cleavage products (NCp15, NCp9 and NCp7) with nucleic acids using solution and single molecule experiments. The NC cleavage products bound DNA with comparable affinity and strongly destabilized the DNA duplex. In contrast, the binding constant of Gag to DNA was found to be approximately 10-fold higher than that of the NC proteins, and its destabilizing effect on dsDNA was negligible. These findings are consistent with the primary function of Gag as a nucleic acid binding and packaging protein and the primary function of the NC proteins as nucleic acid chaperones. Also, our results suggest that NCp7's capability for fast sequence-nonspecific nucleic acid duplex destabilization, as well as its ability to facilitate nucleic acid strand annealing by inducing electrostatic attraction between strands, likely optimize the fully processed NC protein to facilitate complex nucleic acid secondary structure rearrangements. In contrast, Gag's stronger DNA binding and aggregation capabilities likely make it an effective chaperone for processes that do not require significant duplex destabilization.
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Affiliation(s)
- Margareta Cruceanu
- Department of Physics, Northeastern University111 Dana Research Center, 110 Forsyth Street, Boston, MA 02115, USA
| | - Maria A. Urbaneja
- AIDS Vaccine Program, SAIC-Frederick, Inc.NCI at Frederick, Frederick, MD 21702, USA
| | - Catherine V. Hixson
- AIDS Vaccine Program, SAIC-Frederick, Inc.NCI at Frederick, Frederick, MD 21702, USA
| | - Donald G. Johnson
- AIDS Vaccine Program, SAIC-Frederick, Inc.NCI at Frederick, Frederick, MD 21702, USA
| | | | - Matthew J. Fivash
- Data Management Services, Inc.NCI-Frederick, Frederick, MD 2170, USA
| | - Andrew G. Stephen
- Protein Chemistry Laboratory, SAIC Frederick, Inc.NCI at Frederick, Frederick, MD 2170, USA
| | - Robert J. Fisher
- Protein Chemistry Laboratory, SAIC Frederick, Inc.NCI at Frederick, Frederick, MD 2170, USA
| | - Robert J. Gorelick
- AIDS Vaccine Program, SAIC-Frederick, Inc.NCI at Frederick, Frederick, MD 21702, USA
| | | | - Alan Rein
- HIV Drug Resistance Program, NCI-FrederickFrederick, MD 21702-1201, USA
| | - Ioulia Rouzina
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota6-155 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA
| | - Mark C. Williams
- Department of Physics, Northeastern University111 Dana Research Center, 110 Forsyth Street, Boston, MA 02115, USA
- Center for Interdisciplinary Research on Complex Systems, Northeastern University111 Dana Research Center, 110 Forsyth Street, Boston, MA 02115, USA
- To whom correspondence should be addressed. Tel: 1 617 373 7323; Fax: 1 617 373 2943;
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43
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Levin JG, Guo J, Rouzina I, Musier-Forsyth K. Nucleic acid chaperone activity of HIV-1 nucleocapsid protein: critical role in reverse transcription and molecular mechanism. ACTA ACUST UNITED AC 2006; 80:217-86. [PMID: 16164976 DOI: 10.1016/s0079-6603(05)80006-6] [Citation(s) in RCA: 256] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Judith G Levin
- Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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44
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Jenkins LMM, Byrd JC, Hara T, Srivastava P, Mazur SJ, Stahl SJ, Inman JK, Appella E, Omichinski JG, Legault P. Studies on the Mechanism of Inactivation of the HIV-1 Nucleocapsid Protein NCp7 with 2-Mercaptobenzamide Thioesters. J Med Chem 2005; 48:2847-58. [PMID: 15828823 DOI: 10.1021/jm0492195] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The HIV-1 nucleocapsid protein (NCp7) is a small basic protein with two CysCysHisCys zinc-binding domains that specifically recognizes the Psi-site of the viral RNA. NCp7 plays a number of crucial roles in the viral lifecycle, including reverse transcription and RNA encapsidation. Several classes of potential anti-HIV compounds have been designed to inactivate NCp7 through zinc ejection, including a special class of thioester compounds. We have investigated the mechanism of action of two N-substituted-S-acyl-2-mercaptobenzamide compounds (compounds 1 and 2) that target NCp7. UV/Visible spectroscopy studies demonstrated that both thioesters were able to eject metal from NCp7. NMR and mass spectroscopy studies showed that the thioester compounds specifically ejected zinc from the carboxyl-terminal zinc-binding domain of NCp7 by covalent modification of Cys(39). Exposure of NCp7 to compounds 1 and 2 destroyed its ability to specifically bind RNA, whereas NCp7 already bound to RNA was protected from zinc ejection by the thioesters. The thiol component of the thioesters (compound 3, 2-mercaptobenzoyl-beta-alaninamide) did not eject zinc from NCp7, but when compound 3 was incubated with acetyl CoA prior to incubation with NCp7, we observed extensive metal ejection. Thus, the thiol released by the reaction of compounds 1 and 2 could be re-acylated in vivo by acyl CoA to form a new thioester compound that is able to react with NCp7. These studies provide a better understanding of the mechanism of action of thioester compounds, which is important for future design of anti-HIV-1 compounds that target NCp7.
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Affiliation(s)
- Lisa M Miller Jenkins
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
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45
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Tisné C, Guillière F, Dardel F. NMR-based identification of peptides that specifically recognize the d-arm of tRNA. Biochimie 2005; 87:885-8. [PMID: 16164995 DOI: 10.1016/j.biochi.2005.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Accepted: 02/04/2005] [Indexed: 10/25/2022]
Abstract
Human tRNA3(Lys) is used by HIV virus as a primer for the reverse transcription of its genome. The 18 nucleotides at the 3'-end of the tRNA3(Lys) are hybridized to a complementary sequence of the viral RNA called the primer-binding site. A screen against the human tRNA3(Lys) over a peptide library designed to target RNA has been performed. Of the 175 hexapeptides tested, three were found to bind to the d-stem of tRNA3(Lys). Alanine-scanning was used to define the determinants of the interaction between the peptides and tRNA3(Lys). They also bind to two other tested tRNAs, also at the level of the d-stem and loop, although the nucleotide sequence of the stem differs in one of them. These short peptides thus recognize specific structural features within the d-stem and loop of tRNAs. Associated with other pharmacophores, they could be useful to design optimized ligands targeting specific tRNAs such as retroviral replication primers.
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Affiliation(s)
- Carine Tisné
- Laboratoire de Cristallographie et RMN Biologiques, UMR 8015 CNRS/Université Paris 5, Faculté de Pharmacie, 4 avenue de l'Observatoire, 75006 Paris, France.
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46
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Tompa P, Csermely P. The role of structural disorder in the function of RNA and protein chaperones. FASEB J 2005; 18:1169-75. [PMID: 15284216 DOI: 10.1096/fj.04-1584rev] [Citation(s) in RCA: 404] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Chaperones are highly sophisticated protein machines that assist the folding of RNA molecules or other proteins. Their function is generally thought to require a fine-tuned and highly conserved structure: despite the recent recognition of the widespread occurrence of structural disorder in the proteome, this structural trait has never been generally considered in molecular chaperones. In this review we give evidence for the prevalence of functional regions without a well-defined 3-D structure in RNA and protein chaperones. By considering a variety of individual examples, we suggest that the structurally disordered chaperone regions either function as molecular recognition elements that act as solubilizers or locally loosen the structure of the kinetically trapped folding intermediate via transient binding to facilitate its conformational search. The importance of structural disorder is underlined by a predictor of natural disordered regions, which shows an extremely high proportion of such regions, unparalleled in any other protein class, within RNA chaperones: 54.2% of their residues fall into disordered regions and 40% fall within disordered regions longer than 30 consecutive residues. Structural disorder also prevails in protein chaperones, for which frequency values are 36.7% and 15%, respectively. In keeping with these and other details, a novel "entropy transfer" model is presented to account for the mechanistic role of structural disorder in chaperone function.
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Affiliation(s)
- Peter Tompa
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, 1518 Budapest, P.O. Box 7, Hungary.
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47
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Cen S, Niu M, Kleiman L. The connection domain in reverse transcriptase facilitates the in vivo annealing of tRNALys3 to HIV-1 genomic RNA. Retrovirology 2004; 1:33. [PMID: 15494076 PMCID: PMC524520 DOI: 10.1186/1742-4690-1-33] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Accepted: 10/19/2004] [Indexed: 11/19/2022] Open
Abstract
The primer tRNA for reverse transcription in HIV-1, tRNALys3, is selectively packaged into the virus during its assembly, and annealed to the viral genomic RNA. The ribonucleoprotein complex that is involved in the packaging and annealing of tRNALys into HIV-1 consists of Gag, GagPol, tRNALys, lysyl-tRNA synthetase (LysRS), and viral genomic RNA. Gag targets tRNALys for viral packaging through Gag's interaction with LysRS, a tRNALys-binding protein, while reverse transcriptase (RT) sequences within GagPol (the thumb domain) bind to tRNALys. The further annealing of tRNALys3 to viral RNA requires nucleocapsid (NC) sequences in Gag, but not the NC sequences GagPol. In this report, we further show that while the RT connection domain in GagPol is not required for tRNALys3 packaging into the virus, it is required for tRNALys3 annealing to the viral RNA genome.
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Affiliation(s)
- Shan Cen
- Lady Davis Institute for Medical Research and McGill AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada H3T 1E2
- Department of Medicine, McGill University, Montreal, Quebec, Canada H3T 1E2
| | - Meijuan Niu
- Department of Medicine, McGill University, Montreal, Quebec, Canada H3T 1E2
| | - Lawrence Kleiman
- Lady Davis Institute for Medical Research and McGill AIDS Centre, Jewish General Hospital, Montreal, Quebec, Canada H3T 1E2
- Department of Medicine, McGill University, Montreal, Quebec, Canada H3T 1E2
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada H3T 1E2
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48
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Hargittai MRS, Gorelick RJ, Rouzina I, Musier-Forsyth K. Mechanistic insights into the kinetics of HIV-1 nucleocapsid protein-facilitated tRNA annealing to the primer binding site. J Mol Biol 2004; 337:951-68. [PMID: 15033363 DOI: 10.1016/j.jmb.2004.01.054] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2003] [Revised: 01/30/2004] [Accepted: 01/30/2004] [Indexed: 11/22/2022]
Abstract
HIV-1 reverse transcriptase uses human tRNA(Lys,3) as a primer to initiate reverse transcription. Prior to initiation, the 3' 18 nucleotides of this tRNA are annealed to a complementary sequence on the RNA genome known as the primer binding site (PBS). Here, we show that the HIV-1 nucleocapsid protein (NC) enhances this annealing by approximately five orders of magnitude in vitro, decreasing the transition state enthalpy from approximately 20 kcal mol(-1) for the uncatalyzed reaction to 13 kcal mol(-1) for the NC-catalyzed process. Moreover, the annealing follows second-order kinetics, consistent with the nucleation of the intermolecular duplex being the rate-limiting step. This nucleation is preceded by melting of a small duplex region within the original structure, and is followed by much faster zipping of the rest of the 18 base-pair (bp) duplex. A tRNA mutational analysis shows that destabilization of the tRNA acceptor stem has only a minor effect on the annealing rate. In contrast, addition of bases to the 5' end of tRNA that are complementary to its single-stranded 3' end interferes with duplex nucleation and therefore has a much larger effect on the net reaction rate. Assuming that the apparent transition free energy of the annealing reaction, Delta G(++) is a sum of the melting (Delta G(m)) and nucleation (Delta G(nuc)) free energies, we show that NC affects both Delta G(m) and Delta G(nuc). We estimate that ten to 100-fold of the overall rate enhancement is due to NC-induced destabilization of a 4 bp helix in the PBS, while the additional factor of 10(3)-10(4) rate enhancement is a result of NC-facilitated duplex nucleation. The apparently similar effectiveness of wild-type and SSHS NC, a mutant that lacks the zinc finger structures, in facilitating the tRNA annealing reaction is most likely the result of the mutual cancellation of two factors: SSHS NC is less effective than wild-type NC as a duplex destabilizer, but more effective as a duplex nucleating agent.
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Affiliation(s)
- Michele R S Hargittai
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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Tisné C, Roques BP, Dardel F. The annealing mechanism of HIV-1 reverse transcription primer onto the viral genome. J Biol Chem 2003; 279:3588-95. [PMID: 14602716 DOI: 10.1074/jbc.m310368200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Reverse transcription of human immunodeficiency virus-1 viral RNA uses human tRNA(3)(Lys) as a primer. The first step of viral replication is, thus, the annealing of the primer tRNA onto the primer binding site located in the 5' leader region of the viral RNA. This involves large rearrangements of both RNA structures and requires the chaperone activity of the viral nucleocapsid protein. We have developed a novel approach to analyze dynamically such RNA refolding events using heteronuclear NMR spectroscopy of mixtures of (15)N-labeled and unlabeled large RNA fragments (up to 50 kDa). We have thus been able to characterize the detailed mechanisms of both heat- and nucleocapsid-mediated annealing and to identify previously unknown key steps. The role played by the nucleocapsid is 2-fold; it facilitates strand exchange at the level of the tRNA acceptor stem, presumably via its basic N- and C-terminal extensions, and it unlocks the highly stable tertiary interactions at the level of the T Psi C loop, most likely by specific interactions involving its two zinc knuckles.
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Affiliation(s)
- Carine Tisné
- Laboratoire de Cristallographie et Résonance Magnétique Nucléaire Biologiques, UMR 8015 CNRS, 4 avenue de l'Observatoire, 75006 Paris, France
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50
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Lee N, Gorelick RJ, Musier-Forsyth K. Zinc finger-dependent HIV-1 nucleocapsid protein-TAR RNA interactions. Nucleic Acids Res 2003; 31:4847-55. [PMID: 12907727 PMCID: PMC169955 DOI: 10.1093/nar/gkg679] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In the minus-strand transfer step of HIV-1 reverse transcription, the nucleocapsid protein (NC) promotes annealing of the 3' 'R' (repeat) region of the RNA genome to its complementary sequence located in the newly synthesized minus-strand strong-stop DNA. The R region contains the highly stable transactivation response (TAR) RNA hairpin. To gain insights into the molecular details of TAR RNA-NC interactions, we carried out hydroxyl radical footprinting, as well as gel-shift and fluorescence anisotropy binding assays using wild-type and mutant forms of NC. Our results support the conclusion that NC variants with mutations in their zinc finger domains have dramatically altered TAR RNA binding interactions relative to wild-type NC. These data demonstrate that a specific zinc finger architecture is required for optimal TAR RNA binding, and help to explain the requirement for the zinc finger motifs of NC in its role as a nucleic acid chaperone in minus-strand transfer.
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Affiliation(s)
- Nick Lee
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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