1
|
Jiang K, Humbert N, K K S, Rouzina I, Mely Y, Westerlund F. The HIV-1 nucleocapsid chaperone protein forms locally compacted globules on long double-stranded DNA. Nucleic Acids Res 2021; 49:4550-4563. [PMID: 33872352 PMCID: PMC8096146 DOI: 10.1093/nar/gkab236] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 03/09/2021] [Accepted: 03/22/2021] [Indexed: 01/14/2023] Open
Abstract
The nucleocapsid (NC) protein plays key roles in Human Immunodeficiency Virus 1 (HIV-1) replication, notably by condensing and protecting the viral RNA genome and by chaperoning its reverse transcription into double-stranded DNA (dsDNA). Recent findings suggest that integration of viral dsDNA into the host genome, and hence productive infection, is linked to a small subpopulation of viral complexes where reverse transcription was completed within the intact capsid. Therefore, the synthesized dsDNA has to be tightly compacted, most likely by NC, to prevent breaking of the capsid in these complexes. To investigate NC’s ability to compact viral dsDNA, we here characterize the compaction of single dsDNA molecules under unsaturated NC binding conditions using nanofluidic channels. Compaction is shown to result from accumulation of NC at one or few compaction sites, which leads to small dsDNA condensates. NC preferentially initiates compaction at flexible regions along the dsDNA, such as AT-rich regions and DNA ends. Upon further NC binding, these condensates develop into a globular state containing the whole dsDNA molecule. These findings support NC’s role in viral dsDNA compaction within the mature HIV-1 capsid and suggest a possible scenario for the gradual dsDNA decondensation upon capsid uncoating and NC loss.
Collapse
Affiliation(s)
- Kai Jiang
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
| | - Nicolas Humbert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch F 67401, France
| | - Sriram K K
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, The Ohio State University, Center for Retroviral Research, and Center for RNA Biology, Columbus, OH 43210, USA
| | - Yves Mely
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch F 67401, France
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg SE 412 96, Sweden
| |
Collapse
|
2
|
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.
Collapse
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.)
| |
Collapse
|
3
|
Karnib H, Nadeem MF, Humbert N, Sharma KK, Grytsyk N, Tisné C, Boutant E, Lequeu T, Réal E, Boudier C, de Rocquigny H, Mély Y. The nucleic acid chaperone activity of the HIV-1 Gag polyprotein is boosted by its cellular partner RPL7: a kinetic study. Nucleic Acids Res 2020; 48:9218-9234. [PMID: 32797159 PMCID: PMC7498347 DOI: 10.1093/nar/gkaa659] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 07/20/2020] [Accepted: 07/29/2020] [Indexed: 01/10/2023] Open
Abstract
The HIV-1 Gag protein playing a key role in HIV-1 viral assembly has recently been shown to interact through its nucleocapsid domain with the ribosomal protein L7 (RPL7) that acts as a cellular co-factor promoting Gag's nucleic acid (NA) chaperone activity. To further understand how the two proteins act together, we examined their mechanism individually and in concert to promote the annealing between dTAR, the DNA version of the viral transactivation element and its complementary cTAR sequence, taken as model HIV-1 sequences. Gag alone or complexed with RPL7 was found to act as a NA chaperone that destabilizes cTAR stem-loop and promotes its annealing with dTAR through the stem ends via a two-step pathway. In contrast, RPL7 alone acts as a NA annealer that through its NA aggregating properties promotes cTAR/dTAR annealing via two parallel pathways. Remarkably, in contrast to the isolated proteins, their complex promoted efficiently the annealing of cTAR with highly stable dTAR mutants. This was confirmed by the RPL7-promoted boost of the physiologically relevant Gag-chaperoned annealing of (+)PBS RNA to the highly stable tRNALys3 primer, favoring the notion that Gag recruits RPL7 to overcome major roadblocks in viral assembly.
Collapse
Affiliation(s)
- Hassan Karnib
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Muhammad F Nadeem
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Nicolas Humbert
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Kamal K Sharma
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Natalia Grytsyk
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Carine Tisné
- Expression génétique microbienne, UMR 8261, CNRS, Université de Paris, Institut de biologie physico-chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Emmanuel Boutant
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Thiebault Lequeu
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Eleonore Réal
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Christian Boudier
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| | - Hugues de Rocquigny
- Inserm – U1259 Morphogenesis and Antigenicity of HIV and Hepatitis Viruses (MAVIVH), 10 boulevard Tonnellé, BP 3223, 37032 Tours Cedex 1, France
| | - Yves Mély
- Laboratory of Bioimaging and Pathologies (LBP), UMR 7021, Faculty of pharmacy, University of Strasbourg, 67400 Illkirch, France
| |
Collapse
|
4
|
Significant Differences in RNA Structure Destabilization by HIV-1 GagDp6 and NCp7 Proteins. Viruses 2020; 12:v12050484. [PMID: 32344834 PMCID: PMC7290599 DOI: 10.3390/v12050484] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 01/12/2023] Open
Abstract
Retroviral nucleocapsid (NC) proteins are nucleic acid chaperones that play distinct roles in the viral life cycle. During reverse transcription, HIV-1 NC facilitates the rearrangement of nucleic acid secondary structures, allowing the transactivation response (TAR) RNA hairpin to be transiently destabilized and annealed to a complementary RNA hairpin. In contrast, during viral assembly, NC, as a domain of the group-specific antigen (Gag) polyprotein, binds the genomic RNA and facilitates packaging into new virions. It is not clear how the same protein, alone or as part of Gag, performs such different RNA binding functions in the viral life cycle. By combining single-molecule optical tweezers measurements with a quantitative mfold-based model, we characterize the equilibrium stability and unfolding barrier for TAR RNA. Comparing measured results with a model of discrete protein binding allows us to localize affected binding sites, in addition to quantifying hairpin stability. We find that, while both NCp7 and Gag∆p6 destabilize the TAR hairpin, Gag∆p6 binding is localized to two sites in the stem, while NCp7 targets sites near the top loop. Unlike Gag∆p6, NCp7 destabilizes this loop, shifting the location of the reaction barrier toward the folded state and increasing the natural rate of hairpin opening by ~104. Thus, our results explain why Gag cleavage and NC release is an essential prerequisite for reverse transcription within the virion.
Collapse
|
5
|
McCauley MJ, Rouzina I, Williams MC. Specific Nucleic Acid Chaperone Activity of HIV-1 Nucleocapsid Protein Deduced from Hairpin Unfolding. Methods Mol Biol 2020; 2106:59-88. [PMID: 31889251 DOI: 10.1007/978-1-0716-0231-7_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
RNA and DNA hairpin formation and disruption play key regulatory roles in a variety of cellular processes. The 59-nucleotide transactivation response (TAR) RNA hairpin facilitates the production of full-length transcripts of the HIV-1 genome. Yet the stability of this long, irregular hairpin becomes a liability during reverse transcription as 24 base pairs must be disrupted for strand transfer. Retroviral nucleocapsid (NC) proteins serve as nucleic acid chaperones that have been shown to both destabilize the TAR hairpin and facilitate strand annealing with its complementary DNA sequence. Yet it has remained difficult to elucidate the way NC targets and dramatically destabilizes this hairpin while only weakly affecting the annealed product. In this work, we used optical tweezers to measure the stability of TAR and found that adding NC destabilized the hairpin and simultaneously caused a distinct change in both the height and location of the energy barrier. This data was matched to an energy landscape predicted from a simple theory of definite base pair destabilization. Comparisons revealed the specific binding sites found by NC along the irregular TAR hairpin. Furthermore, specific binding explained both the unusual shift in the transition state and the much weaker effect on the annealed product. These experiments illustrate a general method of energy landscape transformation that exposes important physical insights.
Collapse
Affiliation(s)
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, USA
| | - Mark C Williams
- Department of Physics, Northeastern University, Boston, MA, USA.
| |
Collapse
|
6
|
Annealing of ssDNA and compaction of dsDNA by the HIV-1 nucleocapsid and Gag proteins visualized using nanofluidic channels. Q Rev Biophys 2019; 52:e2. [DOI: 10.1017/s0033583518000124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Abstract
The nucleocapsid protein NC is a crucial component in the human immunodeficiency virus type 1 life cycle. It functions both in its processed mature form and as part of the polyprotein Gag that plays a key role in the formation of new viruses. NC can protect nucleic acids (NAs) from degradation by compacting them to a dense coil. Moreover, through its NA chaperone activity, NC can also promote the most stable conformation of NAs. Here, we explore the balance between these activities for NC and Gag by confining DNA–protein complexes in nanochannels. The chaperone activity is visualized as concatemerization and circularization of long DNA via annealing of short single-stranded DNA overhangs. The first ten amino acids of NC are important for the chaperone activity that is almost completely absent for Gag. Gag condenses DNA more efficiently than mature NC, suggesting that additional residues of Gag are involved. Importantly, this is the first single DNA molecule study of full-length Gag and we reveal important differences to the truncated Δ-p6 Gag that has been used before. In addition, the study also highlights how nanochannels can be used to study reactions on ends of long single DNA molecules, which is not trivial with competing single DNA molecule techniques.
Collapse
|
7
|
Abstract
RNA-binding proteins chaperone the biological functions of noncoding RNA by reducing RNA misfolding, improving matchmaking between regulatory RNA and targets, and exerting quality control over RNP biogenesis. Recent studies of Escherichia coli CspA, HIV NCp, and E. coli Hfq are beginning to show how RNA-binding proteins remodel RNA structures. These different protein families use common strategies for disrupting or annealing RNA double helices, which can be used to understand the mechanisms by which proteins chaperone RNA-dependent regulation in bacteria.
Collapse
|
8
|
Wu W, Hatterschide J, Syu YC, Cantara WA, Blower RJ, Hanson HM, Mansky LM, Musier-Forsyth K. Human T-cell leukemia virus type 1 Gag domains have distinct RNA-binding specificities with implications for RNA packaging and dimerization. J Biol Chem 2018; 293:16261-16276. [PMID: 30217825 DOI: 10.1074/jbc.ra118.005531] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 09/13/2018] [Indexed: 12/14/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is the first retrovirus that has conclusively been shown to cause human diseases. In HIV-1, specific interactions between the nucleocapsid (NC) domain of the Gag protein and genomic RNA (gRNA) mediate gRNA dimerization and selective packaging; however, the mechanism for gRNA packaging in HTLV-1, a deltaretrovirus, is unclear. In other deltaretroviruses, the matrix (MA) and NC domains of Gag are both involved in gRNA packaging, but MA binds nucleic acids with higher affinity and has more robust chaperone activity, suggesting that this domain may play a primary role. Here, we show that the MA domain of HTLV-1, but not the NC domain, binds short hairpin RNAs derived from the putative gRNA packaging signal. RNA probing of the HTLV-1 5' leader and cross-linking studies revealed that the primer-binding site and a region within the putative packaging signal form stable hairpins that interact with MA. In addition to a previously identified palindromic dimerization initiation site (DIS), we identified a new DIS in HTLV-1 gRNA and found that both palindromic sequences bind specifically the NC domain. Surprisingly, a mutant partially defective in dimer formation in vitro exhibited a significant increase in RNA packaging into HTLV-1-like particles, suggesting that efficient RNA dimerization may not be strictly required for RNA packaging in HTLV-1. Moreover, the lifecycle of HTLV-1 and other deltaretroviruses may be characterized by NC and MA functions that are distinct from those of the corresponding HIV-1 proteins, but together provide the functions required for viral replication.
Collapse
Affiliation(s)
- Weixin Wu
- From the Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus Ohio 43210 and
| | - Joshua Hatterschide
- From the Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus Ohio 43210 and
| | - Yu-Ci Syu
- From the Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus Ohio 43210 and
| | - William A Cantara
- From the Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus Ohio 43210 and
| | | | - Heather M Hanson
- Institute for Molecular Virology.,Molecular, Cellular, Developmental Biology and Genetics Graduate Program, and
| | - Louis M Mansky
- Institute for Molecular Virology.,Molecular, Cellular, Developmental Biology and Genetics Graduate Program, and.,Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - Karin Musier-Forsyth
- From the Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus Ohio 43210 and
| |
Collapse
|
9
|
Naufer MN, Furano AV, Williams MC. Protein-nucleic acid interactions of LINE-1 ORF1p. Semin Cell Dev Biol 2018; 86:140-149. [PMID: 29596909 PMCID: PMC6428221 DOI: 10.1016/j.semcdb.2018.03.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/19/2018] [Accepted: 03/23/2018] [Indexed: 11/03/2022]
Abstract
Long interspersed nuclear element 1 (LINE-1 or L1) is the dominant retrotransposon in mammalian genomes. L1 encodes two proteins ORF1p and ORF2p that are required for retrotransposition. ORF2p functions as the replicase. ORF1p is a coiled coil-mediated trimeric, high affinity RNA binding protein that packages its full- length coding transcript into an ORF2p-containing ribonucleoprotein (RNP) complex, the retrotransposition intermediate. ORF1p also is a nucleic acid chaperone that presumably facilitates the proposed nucleic acid remodeling steps involved in retrotransposition. Although detailed mechanistic understanding of ORF1p function in this process is lacking, recent studies showed that the rate at which ORF1p can form stable nucleic acid-bound oligomers in vitro is positively correlated with formation of an active L1 RNP as assayed in vivo using a cell culture-based retrotransposition assay. This rate was sensitive to minor amino acid changes in the coiled coil domain, which had no effect on nucleic acid chaperone activity. Additional studies linking the complex nucleic acid binding properties to the conformational changes of the protein are needed to understand how ORF1p facilitates retrotransposition.
Collapse
Affiliation(s)
- M Nabuan Naufer
- Northeastern University, Department of Physics, Boston, MA 02115, USA
| | - Anthony V Furano
- The Laboratory of Molecular and Cellular Biology, NIDDK, NIH, Bethesda, MD 20892, USA
| | - Mark C Williams
- Northeastern University, Department of Physics, Boston, MA 02115, USA.
| |
Collapse
|
10
|
Sancineto L, Iraci N, Tabarrini O, Santi C. NCp7: targeting a multitasking protein for next-generation anti-HIV drug development part 1: covalent inhibitors. Drug Discov Today 2017; 23:260-271. [PMID: 29107765 DOI: 10.1016/j.drudis.2017.10.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Revised: 10/02/2017] [Accepted: 10/17/2017] [Indexed: 11/16/2022]
Abstract
The major internal component of the HIV virion core is the nucleocapsid protein 7 (NCp7), a small, highly basic protein that is essential for multiple stages of the viral replicative cycle, and whose structure is preserved in all viral strains, including clinical isolates from therapy-experienced patients. This key protein is recognised as a potential target for an effective next-generation antiretroviral therapy, because it could offer the possibility to develop broad-spectrum agents that are less prone to select for resistant strains. Here, we provide a comprehensive overview of the covalent NCp7 inhibitors that have emerged over the past 25 years of drug discovery campaigns, emphasising, where possible, their structure-activity relationships (SARs) and pharmacophoric features.
Collapse
Affiliation(s)
- Luca Sancineto
- Department of Heterorganic Chemistry, Centre of Molecular and Macromolecular Studies, Lodz, Poland.
| | - Nunzio Iraci
- Department of Pharmacy, University of Salerno, Fisciano, Salerno, Italy
| | - Oriana Tabarrini
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Claudio Santi
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| |
Collapse
|
11
|
The multiple roles of the nucleocapsid in retroviral RNA conversion into proviral DNA by reverse transcriptase. Biochem Soc Trans 2017; 44:1427-1440. [PMID: 27911725 DOI: 10.1042/bst20160101-t] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 08/08/2016] [Accepted: 08/17/2016] [Indexed: 01/27/2023]
Abstract
Retroviruses are enveloped plus-strand RNA viruses that can cause cancer, immunodeficiency and neurological disorder in human and animals. Retroviruses have several unique properties, such as a genomic RNA in a dimeric form found in the virus, and a replication strategy called 'copy-and-paste' during which the plus-strand genomic RNA is converted into a double-stranded DNA, subsequently integrated into the cellular genome. Two essential viral enzymes, reverse transcriptase (RT) and integrase (IN), direct this 'copy-and-paste' replication. RT copies the genomic RNA generating the double-stranded proviral DNA, while IN catalyzes proviral DNA integration into the cellular DNA, then called the provirus. In that context, a major component of the virion core, the nucleocapsid protein (NC), was found to be a potent nucleic-acid chaperone that assists RT during the conversion of the genomic RNA into proviral DNA. Here we briefly review the interplay of NC with viral nucleic-acids, which enables rapid and faithful folding and hybridization of complementary sequences, and with active RT thus providing assistance to the synthesis of the complete proviral DNA. Because of its multiple roles in retrovirus replication, NC could be viewed as a two-faced Janus-chaperone acting on viral nucleic-acids and enzymes.
Collapse
|
12
|
Jarillo J, Morín JA, Beltrán-Heredia E, Villaluenga JPG, Ibarra B, Cao FJ. Mechanics, thermodynamics, and kinetics of ligand binding to biopolymers. PLoS One 2017; 12:e0174830. [PMID: 28380044 PMCID: PMC5381885 DOI: 10.1371/journal.pone.0174830] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Accepted: 03/15/2017] [Indexed: 01/20/2023] Open
Abstract
Ligands binding to polymers regulate polymer functions by changing their physical and chemical properties. This ligand regulation plays a key role in many biological processes. We propose here a model to explain the mechanical, thermodynamic, and kinetic properties of the process of binding of small ligands to long biopolymers. These properties can now be measured at the single molecule level using force spectroscopy techniques. Our model performs an effective decomposition of the ligand-polymer system on its covered and uncovered regions, showing that the elastic properties of the ligand-polymer depend explicitly on the ligand coverage of the polymer (i.e., the fraction of the polymer covered by the ligand). The equilibrium coverage that minimizes the free energy of the ligand-polymer system is computed as a function of the applied force. We show how ligands tune the mechanical properties of a polymer, in particular its length and stiffness, in a force dependent manner. In addition, it is shown how ligand binding can be regulated applying mechanical tension on the polymer. Moreover, the binding kinetics study shows that, in the case where the ligand binds and organizes the polymer in different modes, the binding process can present transient shortening or lengthening of the polymer, caused by changes in the relative coverage by the different ligand modes. Our model will be useful to understand ligand-binding regulation of biological processes, such as the metabolism of nucleic acid. In particular, this model allows estimating the coverage fraction and the ligand mode characteristics from the force extension curves of a ligand-polymer system.
Collapse
Affiliation(s)
- Javier Jarillo
- Departamento de Física Atómica, Molecular y Nuclear. Facultad de Ciencias Físicas. Universidad Complutense de Madrid. Pza. de las Ciencias, 1. Madrid. Spain
| | - José A. Morín
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit ‘Unidad de Nanobiotecnología’, Madrid, Spain
| | - Elena Beltrán-Heredia
- Departamento de Física Atómica, Molecular y Nuclear. Facultad de Ciencias Físicas. Universidad Complutense de Madrid. Pza. de las Ciencias, 1. Madrid. Spain
| | - Juan P. G. Villaluenga
- Departamento de Física Aplicada I. Facultad de Ciencias Físicas. Universidad Complutense de Madrid. Pza. de las Ciencias, 1. Madrid. Spain
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit ‘Unidad de Nanobiotecnología’, Madrid, Spain
| | - Francisco J. Cao
- Departamento de Física Atómica, Molecular y Nuclear. Facultad de Ciencias Físicas. Universidad Complutense de Madrid. Pza. de las Ciencias, 1. Madrid. Spain
- * E-mail:
| |
Collapse
|
13
|
Post K, Olson ED, Naufer MN, Gorelick RJ, Rouzina I, Williams MC, Musier-Forsyth K, Levin JG. Mechanistic differences between HIV-1 and SIV nucleocapsid proteins and cross-species HIV-1 genomic RNA recognition. Retrovirology 2016; 13:89. [PMID: 28034301 PMCID: PMC5198506 DOI: 10.1186/s12977-016-0322-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/29/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The nucleocapsid (NC) domain of HIV-1 Gag is responsible for specific recognition and packaging of genomic RNA (gRNA) into new viral particles. This occurs through specific interactions between the Gag NC domain and the Psi packaging signal in gRNA. In addition to this critical function, NC proteins are also nucleic acid (NA) chaperone proteins that facilitate NA rearrangements during reverse transcription. Although the interaction with Psi and chaperone activity of HIV-1 NC have been well characterized in vitro, little is known about simian immunodeficiency virus (SIV) NC. Non-human primates are frequently used as a platform to study retroviral infection in vivo; thus, it is important to understand underlying mechanistic differences between HIV-1 and SIV NC. RESULTS Here, we characterize SIV NC chaperone activity for the first time. Only modest differences are observed in the ability of SIV NC to facilitate reactions that mimic the minus-strand annealing and transfer steps of reverse transcription relative to HIV-1 NC, with the latter displaying slightly higher strand transfer and annealing rates. Quantitative single molecule DNA stretching studies and dynamic light scattering experiments reveal that these differences are due to significantly increased DNA compaction energy and higher aggregation capability of HIV-1 NC relative to the SIV protein. Using salt-titration binding assays, we find that both proteins are strikingly similar in their ability to specifically interact with HIV-1 Psi RNA. In contrast, they do not demonstrate specific binding to an RNA derived from the putative SIV packaging signal. CONCLUSIONS Based on these studies, we conclude that (1) HIV-1 NC is a slightly more efficient NA chaperone protein than SIV NC, (2) mechanistic differences between the NA interactions of highly similar retroviral NC proteins are revealed by quantitative single molecule DNA stretching, and (3) SIV NC demonstrates cross-species recognition of the HIV-1 Psi RNA packaging signal.
Collapse
Affiliation(s)
- Klara Post
- Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780 USA
| | - Erik D. Olson
- Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus, OH 43210 USA
| | - M. Nabuan Naufer
- Department of Physics, Northeastern University, Boston, MA 02115 USA
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702-1201 USA
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus, OH 43210 USA
| | - Mark C. Williams
- Department of Physics, Northeastern University, Boston, MA 02115 USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retrovirus Research, and Center for RNA Biology, The Ohio State University, Columbus, OH 43210 USA
| | - Judith G. Levin
- Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780 USA
| |
Collapse
|
14
|
Bernacchi S, Abd El-Wahab EW, Dubois N, Hijnen M, Smyth RP, Mak J, Marquet R, Paillart JC. HIV-1 Pr55 Gag binds genomic and spliced RNAs with different affinity and stoichiometry. RNA Biol 2016; 14:90-103. [PMID: 27841704 DOI: 10.1080/15476286.2016.1256533] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
The HIV-1 Pr55Gag precursor specifically selects genomic RNA (gRNA) from a large variety of cellular and spliced viral RNAs (svRNAs), however the molecular mechanisms of this selective recognition remains poorly understood. To gain better understanding of this process, we analyzed the interactions between Pr55Gag and a large panel of viral RNA (vRNA) fragments encompassing the main packaging signal (Psi) and its flanking regions by fluorescence spectroscopy. We showed that the gRNA harbors a high affinity binding site which is absent from svRNA species, suggesting that this site might be crucial for selecting the HIV-1 genome. Our stoichiometry analysis of protein/RNA complexes revealed that few copies of Pr55Gag specifically associate with the 5' region of the gRNA. Besides, we found that gRNA dimerization significantly impacts Pr55Gag binding, and we confirmed that the internal loop of stem-loop 1 (SL1) in Psi is crucial for specific interaction with Pr55Gag. Our analysis of gRNA fragments of different length supports the existence of a long-range tertiary interaction involving sequences upstream and downstream of the Psi region. This long-range interaction might promote optimal exposure of SL1 for efficient Pr55Gag recognition. Altogether, our results shed light on the molecular mechanisms allowing the specific selection of gRNA by Pr55Gag among a variety of svRNAs, all harboring SL1 in their first common exon.
Collapse
Affiliation(s)
- Serena Bernacchi
- a Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN , Strasbourg , France
| | - Ekram W Abd El-Wahab
- a Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN , Strasbourg , France
| | - Noé Dubois
- a Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN , Strasbourg , France
| | - Marcel Hijnen
- b Centre for Virology, Burnet Institute , Melbourne , Victoria , Australia.,c Department of Biochemistry and Molecular Biology , Monash University , Clayton , Victoria , Australia
| | - Redmond P Smyth
- a Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN , Strasbourg , France
| | - Johnson Mak
- b Centre for Virology, Burnet Institute , Melbourne , Victoria , Australia.,c Department of Biochemistry and Molecular Biology , Monash University , Clayton , Victoria , Australia.,d School of Medicine, Faculty of Health, Deakin University , Geelong , Victoria , Australia.,e Commonwealth Scientific and Industrial Research Organization, Livestock Industries, Australian Animal Health Laboratory , Geelong , Victoria , Australia
| | - Roland Marquet
- a Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN , Strasbourg , France
| | | |
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
McCauley MJ, Rouzina I, Manthei KA, Gorelick RJ, Musier-Forsyth K, Williams MC. Targeted binding of nucleocapsid protein transforms the folding landscape of HIV-1 TAR RNA. Proc Natl Acad Sci U S A 2015; 112:13555-60. [PMID: 26483503 PMCID: PMC4640786 DOI: 10.1073/pnas.1510100112] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Retroviral nucleocapsid (NC) proteins are nucleic acid chaperones that play a key role in the viral life cycle. During reverse transcription, HIV-1 NC facilitates the rearrangement of nucleic acid secondary structure, allowing the transactivation response (TAR) RNA hairpin to be transiently destabilized and annealed to a cDNA hairpin. It is not clear how NC specifically destabilizes TAR RNA but does not strongly destabilize the resulting annealed RNA-DNA hybrid structure, which must be formed for reverse transcription to continue. By combining single-molecule optical tweezers measurements with a quantitative mfold-based model, we characterize the equilibrium TAR stability and unfolding barrier for TAR RNA. Experiments show that adding NC lowers the transition state barrier height while also dramatically shifting the barrier location. Incorporating TAR destabilization by NC into the mfold-based model reveals that a subset of preferential protein binding sites is responsible for the observed changes in the unfolding landscape, including the unusual shift in the transition state. We measure the destabilization induced at these NC binding sites and find that NC preferentially targets TAR RNA by binding to specific sequence contexts that are not present on the final annealed RNA-DNA hybrid structure. Thus, specific binding alters the entire RNA unfolding landscape, resulting in the dramatic destabilization of this specific structure that is required for reverse transcription.
Collapse
Affiliation(s)
- Micah J McCauley
- Department of Physics, Northeastern University, Boston, MA 02115
| | - Ioulia Rouzina
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Kelly A Manthei
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retroviral Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210
| | - Mark C Williams
- Department of Physics, Northeastern University, Boston, MA 02115;
| |
Collapse
|
17
|
Mori M, Kovalenko L, Lyonnais S, Antaki D, Torbett BE, Botta M, Mirambeau G, Mély Y. Nucleocapsid Protein: A Desirable Target for Future Therapies Against HIV-1. Curr Top Microbiol Immunol 2015; 389:53-92. [PMID: 25749978 PMCID: PMC7122173 DOI: 10.1007/82_2015_433] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The currently available anti-HIV-1 therapeutics is highly beneficial to infected patients. However, clinical failures occur as a result of the ability of HIV-1 to rapidly mutate. One approach to overcome drug resistance is to target HIV-1 proteins that are highly conserved among phylogenetically distant viral strains and currently not targeted by available therapies. In this respect, the nucleocapsid (NC) protein, a zinc finger protein, is particularly attractive, as it is highly conserved and plays a central role in virus replication, mainly by interacting with nucleic acids. The compelling rationale for considering NC as a viable drug target is illustrated by the fact that point mutants of this protein lead to noninfectious viruses and by the inability to select viruses resistant to a first generation of anti-NC drugs. In our review, we discuss the most relevant properties and functions of NC, as well as recent developments of small molecules targeting NC. Zinc ejectors show strong antiviral activity, but are endowed with a low therapeutic index due to their lack of specificity, which has resulted in toxicity. Currently, they are mainly being investigated for use as topical microbicides. Greater specificity may be achieved by using non-covalent NC inhibitors (NCIs) targeting the hydrophobic platform at the top of the zinc fingers or key nucleic acid partners of NC. Within the last few years, innovative methodologies have been developed to identify NCIs. Though the antiviral activity of the identified NCIs needs still to be improved, these compounds strongly support the druggability of NC and pave the way for future structure-based design and optimization of efficient NCIs.
Collapse
Affiliation(s)
- Mattia Mori
- Dipartimento di Biotecnologie Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Nishida Y, Pachulska-Wieczorek K, Błaszczyk L, Saha A, Gumna J, Garfinkel DJ, Purzycka KJ. Ty1 retrovirus-like element Gag contains overlapping restriction factor and nucleic acid chaperone functions. Nucleic Acids Res 2015; 43:7414-31. [PMID: 26160887 PMCID: PMC4551931 DOI: 10.1093/nar/gkv695] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 06/26/2015] [Indexed: 12/13/2022] Open
Abstract
Ty1 Gag comprises the capsid of virus-like particles and provides nucleic acid chaperone (NAC) functions during retrotransposition in budding yeast. A subgenomic Ty1 mRNA encodes a truncated Gag protein (p22) that is cleaved by Ty1 protease to form p18. p22/p18 strongly inhibits transposition and can be considered an element-encoded restriction factor. Here, we show that only p22 and its short derivatives restrict Ty1 mobility whereas other regions of GAG inhibit mobility weakly if at all. Mutational analyses suggest that p22/p18 is synthesized from either of two closely spaced AUG codons. Interestingly, AUG1p18 and AUG2p18 proteins display different properties, even though both contain a region crucial for RNA binding and NAC activity. AUG1p18 shows highly reduced NAC activity but specific binding to Ty1 RNA, whereas AUG2p18 shows the converse behavior. p22/p18 affects RNA encapsidation and a mutant derivative defective for RNA binding inhibits the RNA chaperone activity of the C-terminal region (CTR) of Gag-p45. Moreover, affinity pulldowns show that p18 and the CTR interact. These results support the idea that one aspect of Ty1 restriction involves inhibition of Gag-p45 NAC functions by p22/p18-Gag interactions.
Collapse
Affiliation(s)
- Yuri Nishida
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Katarzyna Pachulska-Wieczorek
- Department of Structural Chemistry and Biology of Nucleic Acids, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - Leszek Błaszczyk
- Institute of Computing Science, Poznan University of Technology, 60-965 Poznan, Poland
| | - Agniva Saha
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Julita Gumna
- Department of Structural Chemistry and Biology of Nucleic Acids, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| | - David J Garfinkel
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Katarzyna J Purzycka
- Department of Structural Chemistry and Biology of Nucleic Acids, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
| |
Collapse
|
19
|
Potempa M, Lee SK, Wolfenden R, Swanstrom R. The triple threat of HIV-1 protease inhibitors. Curr Top Microbiol Immunol 2015; 389:203-41. [PMID: 25778681 DOI: 10.1007/82_2015_438] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Newly released human immunodeficiency virus type 1 (HIV-1) particles obligatorily undergo a maturation process to become infectious. The HIV-1 protease (PR) initiates this step, catalyzing the cleavage of the Gag and Gag-Pro-Pol structural polyproteins. Proper organization of the mature virus core requires that cleavage of these polyprotein substrates proceeds in a highly regulated, specific series of events. The vital role the HIV-1 PR plays in the viral life cycle has made it an extremely attractive target for inhibition and has accordingly fostered the development of a number of highly potent substrate-analog inhibitors. Though the PR inhibitors (PIs) inhibit only the HIV-1 PR, their effects manifest at multiple different stages in the life cycle due to the critical importance of the PR in preparing the virus for these subsequent events. Effectively, PIs masquerade as entry inhibitors, reverse transcription inhibitors, and potentially even inhibitors of post-reverse transcription steps. In this chapter, we review the triple threat of PIs: the intermolecular cooperativity in the form of a cooperative dose-response for inhibition in which the apparent potency increases with increasing inhibition; the pleiotropic effects of HIV-1 PR inhibition on entry, reverse transcription, and post-reverse transcription steps; and their potency as transition state analogs that have the potential for further improvement that could lead to an inability of the virus to evolve resistance in the context of single drug therapy.
Collapse
Affiliation(s)
- Marc Potempa
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, 27599, USA
| | | | | | | |
Collapse
|
20
|
Rocha MS. Extracting physical chemistry from mechanics: a new approach to investigate DNA interactions with drugs and proteins in single molecule experiments. Integr Biol (Camb) 2015; 7:967-86. [DOI: 10.1039/c5ib00127g] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In this review we focus on the idea of establishing connections between the mechanical properties of DNA–ligand complexes and the physical chemistry of DNA–ligand interactions.
Collapse
Affiliation(s)
- M. S. Rocha
- Laboratório de Física Biológica
- Departamento de Física
- Universidade Federal de Viçosa
- Viçosa
- Brazil
| |
Collapse
|
21
|
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.
Collapse
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.
| |
Collapse
|
22
|
Wu T, Gorelick RJ, Levin JG. Selection of fully processed HIV-1 nucleocapsid protein is required for optimal nucleic acid chaperone activity in reverse transcription. Virus Res 2014; 193:52-64. [PMID: 24954787 PMCID: PMC4252486 DOI: 10.1016/j.virusres.2014.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/09/2014] [Accepted: 06/10/2014] [Indexed: 12/14/2022]
Abstract
The mature HIV-1 nucleocapsid protein (NCp7) is generated by sequential proteolytic cleavage of precursor proteins containing additional C-terminal peptides: NCp15 (NCp7-spacer peptide 2 (SP2)-p6); and NCp9 (NCp7-SP2). Here, we compare the nucleic acid chaperone activities of the three proteins, using reconstituted systems that model the annealing and elongation steps in tRNA(Lys3)-primed (-) strong-stop DNA synthesis and subsequent minus-strand transfer. The maximum levels of annealing are similar for all of the proteins, but there are important differences in their ability to facilitate reverse transcriptase (RT)-catalyzed DNA extension. Thus, at low concentrations, NCp9 has the greatest activity, but with increasing concentrations, DNA synthesis is significantly reduced. This finding reflects NCp9's strong nucleic acid binding affinity (associated with the highly basic SP2 domain) as well as its slow dissociation kinetics, which together limit the ability of RT to traverse the nucleic acid template. NCp15 has the poorest activity of the three proteins due to its acidic p6 domain. Indeed, mutants with alanine substitutions for the acidic residues in p6 have improved chaperone function. Collectively, these data can be correlated with the known biological properties of NCp9 and NCp15 mutant virions and help to explain why mature NC has evolved as the critical cofactor for efficient virus replication and long-term viral fitness.
Collapse
Affiliation(s)
- Tiyun Wu
- Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702-1201, USA
| | - Judith G Levin
- Section on Viral Gene Regulation, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA.
| |
Collapse
|
23
|
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.
Collapse
|
24
|
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.
Collapse
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:
| |
Collapse
|
25
|
Pachulska-Wieczorek K, Stefaniak AK, Purzycka KJ. Similarities and differences in the nucleic acid chaperone activity of HIV-2 and HIV-1 nucleocapsid proteins in vitro. Retrovirology 2014; 11:54. [PMID: 24992971 PMCID: PMC4227088 DOI: 10.1186/1742-4690-11-54] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/23/2014] [Indexed: 01/22/2023] Open
Abstract
Background The nucleocapsid domain of Gag and mature nucleocapsid protein (NC) act as nucleic acid chaperones and facilitate folding of nucleic acids at critical steps of retroviral replication cycle. The basic N-terminus of HIV-1 NC protein was shown most important for the chaperone activity. The HIV-2 NC (NCp8) and HIV-1 NC (NCp7) proteins possess two highly conserved zinc fingers, flanked by basic residues. However, the NCp8 N-terminal domain is significantly shorter and contains less positively charged residues. This study characterizes previously unknown, nucleic acid chaperone activity of the HIV-2 NC protein. Results We have comparatively investigated the in vitro nucleic acid chaperone properties of the HIV-2 and HIV-1 NC proteins. Using substrates derived from the HIV-1 and HIV-2 genomes, we determined the ability of both proteins to chaperone nucleic acid aggregation, annealing and strand exchange in duplex structures. Both NC proteins displayed comparable, high annealing activity of HIV-1 TAR DNA and its complementary nucleic acid. Interesting differences between the two NC proteins were discovered when longer HIV substrates, particularly those derived from the HIV-2 genome, were used in chaperone assays. In contrast to NCp7, NCp8 weakly facilitates annealing of HIV-2 TAR RNA to its complementary TAR (−) DNA. NCp8 is also unable to efficiently stimulate tRNALys3 annealing to its respective HIV-2 PBS motif. Using truncated NCp8 peptide, we demonstrated that despite the fact that the N-terminus of NCp8 differs from that of NCp7, this domain is essential for NCp8 activity. Conclusion Our data demonstrate that the HIV-2 NC protein displays reduced nucleic acid chaperone activity compared to that of HIV-1 NC. We found that NCp8 activity is limited by substrate length and stability to a greater degree than that of NCp7. This is especially interesting in light of the fact that the HIV-2 5′UTR is more structured than that of HIV-1. The reduced chaperone activity observed with NCp8 may influence the efficiency of reverse transcription and other key steps of the HIV-2 replication cycle.
Collapse
|
26
|
Retrospective on the all-in-one retroviral nucleocapsid protein. Virus Res 2014; 193:2-15. [PMID: 24907482 PMCID: PMC7114435 DOI: 10.1016/j.virusres.2014.05.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 05/11/2014] [Accepted: 05/11/2014] [Indexed: 01/08/2023]
Abstract
This retrospective reviews 30 years of research on the retroviral nucleocapsid protein (NC) focusing on HIV-1 NC. Originally considered as a non-specific nucleic-acid binding protein, NC has seminal functions in virus replication. Indeed NC turns out to be a all-in-one viral protein that chaperones viral DNA synthesis and integration, and virus formation. As a chaperone NC provides assistance to genetic recombination thus allowing the virus to escape the immune response and antiretroviral therapies against HIV-1.
This review aims at briefly presenting a retrospect on the retroviral nucleocapsid protein (NC), from an unspecific nucleic acid binding protein (NABP) to an all-in-one viral protein with multiple key functions in the early and late phases of the retrovirus replication cycle, notably reverse transcription of the genomic RNA and viral DNA integration into the host genome, and selection of the genomic RNA together with the initial steps of virus morphogenesis. In this context we will discuss the notion that NC protein has a flexible conformation and is thus a member of the growing family of intrinsically disordered proteins (IDPs) where disorder may account, at least in part, for its function as a nucleic acid (NA) chaperone and possibly as a protein chaperone vis-à-vis the viral DNA polymerase during reverse transcription. Lastly, we will briefly review the development of new anti-retroviral/AIDS compounds targeting HIV-1 NC because it represents an ideal target due to its multiple roles in the early and late phases of virus replication and its high degree of conservation.
Collapse
|
27
|
Wang W, Naiyer N, Mitra M, Li J, Williams MC, Rouzina I, Gorelick RJ, Wu Z, Musier-Forsyth K. Distinct nucleic acid interaction properties of HIV-1 nucleocapsid protein precursor NCp15 explain reduced viral infectivity. Nucleic Acids Res 2014; 42:7145-59. [PMID: 24813443 PMCID: PMC4066767 DOI: 10.1093/nar/gku335] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
During human immunodeficiency virus type 1 (HIV-1) maturation, three different forms of nucleocapsid (NC) protein—NCp15 (p9 + p6), NCp9 (p7 + SP2) and NCp7—appear successively. A mutant virus expressing NCp15 shows greatly reduced infectivity. Mature NCp7 is a chaperone protein that facilitates remodeling of nucleic acids (NAs) during reverse transcription. To understand the strict requirement for NCp15 processing, we compared the chaperone function of the three forms of NC. NCp15 anneals tRNA to the primer-binding site at a similar rate as NCp7, whereas NCp9 is the most efficient annealing protein. Assays to measure NA destabilization show a similar trend. Dynamic light scattering studies reveal that NCp15 forms much smaller aggregates relative to those formed by NCp7 and NCp9. Nuclear magnetic resonance studies suggest that the acidic p6 domain of HIV-1 NCp15 folds back and interacts with the basic zinc fingers. Neutralizing the acidic residues in p6 improves the annealing and aggregation activity of NCp15 to the level of NCp9 and increases the protein–NA aggregate size. Slower NCp15 dissociation kinetics is observed by single-molecule DNA stretching, consistent with the formation of electrostatic inter-protein contacts, which likely contribute to the distinct aggregate morphology, irregular HIV-1 core formation and non-infectious virus.
Collapse
Affiliation(s)
- Wei Wang
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Nada Naiyer
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Mithun Mitra
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Jialin Li
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Mark C Williams
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Ioulia Rouzina
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Robert J Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Zhengrong Wu
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retrovirus Research and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| |
Collapse
|
28
|
Sun M, Grigsby IF, Gorelick RJ, Mansky LM, Musier-Forsyth K. Retrovirus-specific differences in matrix and nucleocapsid protein-nucleic acid interactions: implications for genomic RNA packaging. J Virol 2014; 88:1271-80. [PMID: 24227839 PMCID: PMC3911680 DOI: 10.1128/jvi.02151-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/04/2013] [Indexed: 11/20/2022] Open
Abstract
Retroviral RNA encapsidation involves a recognition event between genomic RNA (gRNA) and one or more domains in Gag. In HIV-1, the nucleocapsid (NC) domain is involved in gRNA packaging and displays robust nucleic acid (NA) binding and chaperone functions. In comparison, NC of human T-cell leukemia virus type 1 (HTLV-1), a deltaretrovirus, displays weaker NA binding and chaperone activity. Mutation of conserved charged residues in the deltaretrovirus bovine leukemia virus (BLV) matrix (MA) and NC domains affects virus replication and gRNA packaging efficiency. Based on these observations, we hypothesized that the MA domain may generally contribute to NA binding and genome encapsidation in deltaretroviruses. Here, we examined the interaction between HTLV-2 and HIV-1 MA proteins and various NAs in vitro. HTLV-2 MA displays higher NA binding affinity and better chaperone activity than HIV-1 MA. HTLV-2 MA also binds NAs with higher affinity than HTLV-2 NC and displays more robust chaperone function. Mutation of two basic residues in HTLV-2 MA α-helix II, previously implicated in BLV gRNA packaging, reduces NA binding affinity. HTLV-2 MA binds with high affinity and specificity to RNA derived from the putative packaging signal of HTLV-2 relative to nonspecific NA. Furthermore, an HIV-1 MA triple mutant designed to mimic the basic character of HTLV-2 MA α-helix II dramatically improves binding affinity and chaperone activity of HIV-1 MA in vitro and restores RNA packaging to a ΔNC HIV-1 variant in cell-based assays. Taken together, these results are consistent with a role for deltaretrovirus MA proteins in viral RNA packaging.
Collapse
Affiliation(s)
- Meng Sun
- Department of Chemistry and Biochemistry, Center for Retroviral Research, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| | - Iwen F. Grigsby
- Institute for Molecular Virology, Departments of Diagnostic and Biological Sciences and Microbiology, School of Dentistry and Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Louis M. Mansky
- Institute for Molecular Virology, Departments of Diagnostic and Biological Sciences and Microbiology, School of Dentistry and Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Karin Musier-Forsyth
- Department of Chemistry and Biochemistry, Center for Retroviral Research, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
| |
Collapse
|
29
|
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.
Collapse
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
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Mitra M, Wang W, Vo MN, Rouzina I, Barany G, Musier-Forsyth K. The N-terminal zinc finger and flanking basic domains represent the minimal region of the human immunodeficiency virus type-1 nucleocapsid protein for targeting chaperone function. Biochemistry 2013; 52:8226-36. [PMID: 24144434 DOI: 10.1021/bi401250a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The human immunodeficiency virus type-1 (HIV-1) nucleocapsid (NC) protein is a chaperone that facilitates nucleic acid conformational changes to produce the most thermodynamically stable arrangement. The critical role of NC in many steps of the viral life cycle makes it an attractive therapeutic target. The chaperone activity of NC depends on its nucleic acid aggregating ability, duplex destabilizing activity, and rapid on-off binding kinetics. During the minus-strand transfer step of reverse transcription, NC chaperones the annealing of highly structured transactivation response region (TAR) RNA to the complementary TAR DNA. In this work, the role of different functional domains of NC in facilitating 59-nucleotide TAR RNA-DNA annealing was probed by using chemically synthesized peptides derived from full-length (55 amino acids) HIV-1 NC: NC(1-14), NC(15-35), NC(1-28), NC(1-35), NC(29-55), NC(36-55), and NC(11-55). Most of these peptides displayed significantly reduced annealing kinetics, even when present at concentrations much higher than that of wild-type (WT) NC. In addition, these truncated NC constructs generally bind more weakly to single-stranded DNA and are less effective nucleic acid aggregating agents than full-length NC, consistent with the loss of both electrostatic and hydrophobic contacts. However, NC(1-35) displayed annealing kinetics, nucleic acid binding, and aggregation activity that were very similar to those of WT NC. Thus, we conclude that the N-terminal zinc finger, flanked by the N-terminus and linker domains, represents the minimal sequence that is necessary and sufficient for chaperone function in vitro. In addition, covalent continuity of the 35 N-terminal amino acids of NC is critical for full activity. Thus, although the hydrophobic pocket formed by residues proximal to the C-terminal zinc finger has been a major focus of recent anti-NC therapeutic strategies, NC(1-35) represents an alternative target for therapeutics aimed at disrupting NC's chaperone function.
Collapse
Affiliation(s)
- Mithun Mitra
- Department of Chemistry and Biochemistry, Center for RNA Biology, and Center for Retrovirus Research, The Ohio State University , Columbus, Ohio 43210, United States
| | | | | | | | | | | |
Collapse
|
31
|
Mitra M, Hercík K, Byeon IJL, Ahn J, Hill S, Hinchee-Rodriguez K, Singer D, Byeon CH, Charlton LM, Nam G, Heidecker G, Gronenborn AM, Levin JG. Structural determinants of human APOBEC3A enzymatic and nucleic acid binding properties. Nucleic Acids Res 2013; 42:1095-110. [PMID: 24163103 PMCID: PMC3902935 DOI: 10.1093/nar/gkt945] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human APOBEC3A (A3A) is a single-domain cytidine deaminase that converts deoxycytidine residues to deoxyuridine in single-stranded DNA (ssDNA). It inhibits a wide range of viruses and endogenous retroelements such as LINE-1, but it can also edit genomic DNA, which may play a role in carcinogenesis. Here, we extend our recent findings on the NMR structure of A3A and report structural, biochemical and cell-based mutagenesis studies to further characterize A3A’s deaminase and nucleic acid binding activities. We find that A3A binds ssRNA, but the RNA and DNA binding interfaces differ and no deamination of ssRNA is detected. Surprisingly, with only one exception (G105A), alanine substitution mutants with changes in residues affected by specific ssDNA binding retain deaminase activity. Furthermore, A3A binds and deaminates ssDNA in a length-dependent manner. Using catalytically active and inactive A3A mutants, we show that the determinants of A3A deaminase activity and anti-LINE-1 activity are not the same. Finally, we demonstrate A3A’s potential to mutate genomic DNA during transient strand separation and show that this process could be counteracted by ssDNA binding proteins. Taken together, our studies provide new insights into the molecular properties of A3A and its role in multiple cellular and antiviral functions.
Collapse
Affiliation(s)
- Mithun Mitra
- Section on Viral Gene Regulation, Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-2780, USA, Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA, Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA and HIV Drug Resistance Program, Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Boudier C, Humbert N, Chaminade F, Chen Y, de Rocquigny H, Godet J, Mauffret O, Fossé P, Mély Y. Dynamic interactions of the HIV-1 Tat with nucleic acids are critical for Tat activity in reverse transcription. Nucleic Acids Res 2013; 42:1065-78. [PMID: 24153111 PMCID: PMC3902927 DOI: 10.1093/nar/gkt934] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The HIV-1 transactivator of transcription (Tat) protein is thought to stimulate reverse transcription (RTion). The Tat protein and, more specifically, its (44–61) domain were recently shown to promote the annealing of complementary DNA sequences representing the HIV-1 transactivation response element TAR, named dTAR and cTAR, that plays a key role in RTion. Moreover, the kinetic mechanism of the basic Tat(44–61) peptide in this annealing further revealed that this peptide constitutes a representative nucleic acid annealer. To further understand the structure–activity relationships of this highly conserved domain, we investigated by electrophoresis and fluorescence approaches the binding and annealing properties of various Tat(44–61) mutants. Our data showed that the Tyr47 and basic residues of the Tat(44–61) domain were instrumental for binding to cTAR through stacking and electrostatic interactions, respectively, and promoting its annealing with dTAR. Furthermore, the annealing efficiency of the mutants clearly correlates with their ability to rapidly associate and dissociate the complementary oligonucleotides and to promote RTion. Thus, transient and dynamic nucleic acid interactions likely constitute a key mechanistic component of annealers and the role of Tat in the late steps of RTion. Finally, our data suggest that Lys50 and Lys51 acetylation regulates Tat activity in RTion.
Collapse
Affiliation(s)
- Christian Boudier
- Laboratoire de Biophotonique et Pharmacologie, UMR-CNRS 7213, Faculté de Pharmacie, Université de Strasbourg, Illkirch 67401, France and Laboratoire de Biologie et Pharmacologie Appliquée, UMR-CNRS 8113, Ecole Normale Supérieure de Cachan, Cachan 94235, France
| | | | | | | | | | | | | | | | | |
Collapse
|
33
|
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.
Collapse
Affiliation(s)
- Dona Sleiman
- Laboratoire de Cristallographie et RMN biologiques, CNRS, Université Paris Descartes, Paris Sorbonne Cité, Paris, France
| | | | | | | |
Collapse
|
34
|
Godet J, Kenfack C, Przybilla F, Richert L, Duportail G, Mély Y. Site-selective probing of cTAR destabilization highlights the necessary plasticity of the HIV-1 nucleocapsid protein to chaperone the first strand transfer. Nucleic Acids Res 2013; 41:5036-48. [PMID: 23511968 PMCID: PMC3643577 DOI: 10.1093/nar/gkt164] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The HIV-1 nucleocapsid protein (NCp7) is a nucleic acid chaperone required during reverse transcription. During the first strand transfer, NCp7 is thought to destabilize cTAR, the (−)DNA copy of the TAR RNA hairpin, and subsequently direct the TAR/cTAR annealing through the zipping of their destabilized stem ends. To further characterize the destabilizing activity of NCp7, we locally probe the structure and dynamics of cTAR by steady-state and time resolved fluorescence spectroscopy. NC(11–55), a truncated NCp7 version corresponding to its zinc-finger domain, was found to bind all over the sequence and to preferentially destabilize the penultimate double-stranded segment in the lower part of the cTAR stem. This destabilization is achieved through zinc-finger–dependent binding of NC to the G10 and G50 residues. Sequence comparison further revealed that C•A mismatches close to the two G residues were critical for fine tuning the stability of the lower part of the cTAR stem and conferring to G10 and G50 the appropriate mobility and accessibility for specific recognition by NC. Our data also highlight the necessary plasticity of NCp7 to adapt to the sequence and structure variability of cTAR to chaperone its annealing with TAR through a specific pathway.
Collapse
Affiliation(s)
- Julien Godet
- Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, UMR 7213 CNRS, Université de Strasbourg, 67401 Illkirch, France
| | | | | | | | | | | |
Collapse
|
35
|
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.
Collapse
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
| |
Collapse
|
36
|
Du J, Wu L, Shimada N, Kano A, Maruyama A. Polyelectrolyte-assisted transconformation of a stem-loop DNA. Chem Commun (Camb) 2013; 49:475-7. [DOI: 10.1039/c2cc37139a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
37
|
Role of the SP2 domain and its proteolytic cleavage in HIV-1 structural maturation and infectivity. J Virol 2012; 86:13708-16. [PMID: 23055560 DOI: 10.1128/jvi.01704-12] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
HIV-1 buds as an immature, noninfectious virion. Proteolysis of its main structural component, Gag, is required for morphological maturation and infectivity and leads to release of four functional domains and the spacer peptides SP1 and SP2. The N-terminal cleavages of Gag and the separation of SP1 from CA are all essential for viral infectivity, while the roles of the two C-terminal cleavages and the role of SP2, separating the NC and p6 domains, are less well defined. We have analyzed HIV-1 variants with defective cleavage at either or both sites flanking SP2, or largely lacking SP2, regarding virus production, infectivity, and structural maturation. Neither the presence nor the proteolytic processing of SP2 was required for particle release. Viral infectivity was almost abolished when both cleavage sites were defective and severely reduced when the fast cleavage site between SP2 and p6 was defective. This correlated with an increased proportion of irregular core structures observed by cryo-electron tomography, although processing of CA was unaffected. Mutation of the slow cleavage site between NC and SP2 or deletion of most of SP2 had only a minor effect on infectivity and did not induce major alterations in mature core morphology. We speculate that not only separation of NC and p6 but also the processing kinetics in this region are essential for successful maturation, while SP2 itself is dispensable.
Collapse
|
38
|
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.
Collapse
Affiliation(s)
- Julien Godet
- Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, UMR 7213 CNRS, Université de Strasbourg, 67401 Illkirch, France
| | | | | | | | | | | |
Collapse
|
39
|
Wang H, Musier-Forsyth K, Falk C, Barbara PF. Single-molecule spectroscopic study of dynamic nanoscale DNA bending behavior of HIV-1 nucleocapsid protein. J Phys Chem B 2012; 117:4183-96. [PMID: 22591315 DOI: 10.1021/jp3018259] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We have studied the conformational dynamics associated with the nanoscale DNA bending induced by human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) protein using single-molecule Förster resonance energy transfer (SM-FRET). To gain molecular-level insights into how the HIV-1 NC locally distorts the structures of duplexed DNA segments, the dynamics, reversibility, and sequence specificity of the DNA bending behavior of NC have been systematically studied. We have performed SM-FRET measurements on a series of duplexed DNA segments with varying sequences, lengths, and local structures in the presence of the wide-type HIV-1 NC and NC mutants lacking either the basic N-terminal domain or the zinc fingers. On the basis of the SM-FRET results, we have proposed a possible mechanism for the NC-induced DNA bending in which both NC's zinc fingers and N-terminal domain are found to play crucial roles. The SM-FRET results reported here add new mechanistic insights into the biological behaviors and functions of HIV-1 NC as a retroviral DNA-architectural protein which may play critical roles in the compaction, nuclear import, and integration of the proviral DNA during the retroviral life cycle.
Collapse
Affiliation(s)
- Hui Wang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA.
| | | | | | | |
Collapse
|
40
|
Chaurasiya KR, Geertsema H, Cristofari G, Darlix JL, Williams MC. A single zinc finger optimizes the DNA interactions of the nucleocapsid protein of the yeast retrotransposon Ty3. Nucleic Acids Res 2012; 40:751-60. [PMID: 21917850 PMCID: PMC3258130 DOI: 10.1093/nar/gkr726] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 08/09/2011] [Accepted: 08/23/2011] [Indexed: 12/18/2022] Open
Abstract
Reverse transcription in retroviruses and retrotransposons requires nucleic acid chaperones, which drive the rearrangement of nucleic acid conformation. The nucleic acid chaperone properties of the human immunodeficiency virus type-1 (HIV-1) nucleocapsid (NC) protein have been extensively studied, and nucleic acid aggregation, duplex destabilization and rapid binding kinetics have been identified as major components of its activity. However, the properties of other nucleic acid chaperone proteins, such as retrotransposon Ty3 NC, a likely ancestor of HIV-1 NC, are not well understood. In addition, it is unclear whether a single zinc finger is sufficient to optimize the properties characteristic of HIV-1 NC. We used single-molecule DNA stretching as a method for detailed characterization of Ty3 NC chaperone activity. We found that wild type Ty3 NC aggregates single- and double-stranded DNA, weakly stabilizes dsDNA, and exhibits rapid binding kinetics. Single-molecule studies in the presence of Ty3 NC mutants show that the N-terminal basic residues and the unique zinc finger at the C-terminus are required for optimum chaperone activity in this system. While the single zinc finger is capable of optimizing Ty3 NC's DNA interaction kinetics, two zinc fingers may be necessary in order to facilitate the DNA destabilization exhibited by HIV-1 NC.
Collapse
Affiliation(s)
- Kathy R. Chaurasiya
- Department of Physics, Northeastern University, Boston, MA, USA, Unité de Virologie Humaine INSERM 758, IFR 128 Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon, France and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA, USA
| | - Hylkje Geertsema
- Department of Physics, Northeastern University, Boston, MA, USA, Unité de Virologie Humaine INSERM 758, IFR 128 Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon, France and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA, USA
| | - Gaël Cristofari
- Department of Physics, Northeastern University, Boston, MA, USA, Unité de Virologie Humaine INSERM 758, IFR 128 Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon, France and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA, USA
| | - Jean-Luc Darlix
- Department of Physics, Northeastern University, Boston, MA, USA, Unité de Virologie Humaine INSERM 758, IFR 128 Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon, France and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA, USA
| | - Mark C. Williams
- Department of Physics, Northeastern University, Boston, MA, USA, Unité de Virologie Humaine INSERM 758, IFR 128 Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon, France and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA, USA
| |
Collapse
|
41
|
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.
Collapse
|
42
|
Kanevsky I, Chaminade F, Chen Y, Godet J, René B, Darlix JL, Mély Y, Mauffret O, Fossé P. Structural determinants of TAR RNA-DNA annealing in the absence and presence of HIV-1 nucleocapsid protein. Nucleic Acids Res 2011; 39:8148-62. [PMID: 21724607 PMCID: PMC3185427 DOI: 10.1093/nar/gkr526] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Annealing of the TAR RNA hairpin to the cTAR DNA hairpin is required for the minus-strand transfer step of HIV-1 reverse transcription. HIV-1 nucleocapsid protein (NC) plays a crucial role by facilitating annealing of the complementary hairpins. To gain insight into the mechanism of NC-mediated TAR RNA–DNA annealing, we used structural probes (nucleases and potassium permanganate), gel retardation assays, fluorescence anisotropy and cTAR mutants under conditions allowing strand transfer. In the absence of NC, cTAR DNA-TAR RNA annealing depends on nucleation through the apical loops. We show that the annealing intermediate of the kissing pathway is a loop–loop kissing complex involving six base-pairs and that the apical stems are not destabilized by this loop–loop interaction. Our data support a dynamic structure of the cTAR hairpin in the absence of NC, involving equilibrium between both the closed conformation and the partially open ‘Y’ conformation. This study is the first to show that the apical and internal loops of cTAR are weak and strong binding sites for NC, respectively. NC slightly destabilizes the lower stem that is adjacent to the internal loop and shifts the equilibrium toward the ‘Y’ conformation exhibiting at least 12 unpaired nucleotides in its lower part.
Collapse
Affiliation(s)
- Igor Kanevsky
- LBPA, ENS de Cachan, CNRS, 61 avenue du Président Wilson, 94235 Cachan, France
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Evans JD, Peddigari S, Chaurasiya KR, Williams MC, Martin SL. Paired mutations abolish and restore the balanced annealing and melting activities of ORF1p that are required for LINE-1 retrotransposition. Nucleic Acids Res 2011; 39:5611-21. [PMID: 21441536 PMCID: PMC3141268 DOI: 10.1093/nar/gkr171] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Retrotransposition amplifies LINE-1 (L1) to high copy number in mammalian genomes. The L1 protein encoded by ORF1 (ORF1p) is required for retrotransposition. This dependence on ORF1p was investigated by mutating three highly conserved residues, R238, R284 and Y318 to alanine, thereby inactivating retrotransposition. R284A and Y318A were rescued by further substituting the alanine with the appropriate conservative amino acid, e.g. lysine or phenylalanine, respectively, whereas R238K remained inactive. Quantification of the steady-state levels of L1 RNA and ORF1p failed to discriminate active from inactive variants, indicating loss of L1 retrotransposition resulted from loss of function rather than reduced expression. The two biochemical properties known for ORF1p are high-affinity RNA binding and nucleic acid chaperone activity. Only R238A/K exhibited significantly reduced RNA affinities. The nucleic acid chaperone activities of the remaining paired mutants were assessed by single-molecule DNA stretching and found to mirror retrotransposition activity. To further examine ORF1p chaperone function, their energetic barriers to DNA annealing and melting were derived from kinetic work. When plotted against each other, the ratio of these two activities distinguished functional from non-functional ORF1p variants. These findings enhance our understanding of the requirements for ORF1p in LINE-1 retrotransposition and, more generally, nucleic acid chaperone function.
Collapse
Affiliation(s)
- James D Evans
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | | | | | | | | |
Collapse
|
44
|
Martin SL. Nucleic acid chaperone properties of ORF1p from the non-LTR retrotransposon, LINE-1. RNA Biol 2010; 7:706-11. [PMID: 21045547 DOI: 10.4161/rna.7.6.13766] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Long interspersed element-1 (LINE-1, or L1) is a non-long terminal repeat (LTR) retrotransposon that has amplified to hundreds of thousands of copies in mammalian evolution. A small number of the individual copies of L1 are active retrotransposons which are presently replicating in most species, including humans and mice. L1 retrotransposition begins with transcription of an active element and ends with a newly inserted cDNA copy, a process which requires the two element-encoded proteins to act in cis on the L1 RNA. The ORF1 protein (ORF1p) is a high-affinity, non-sequence-specific RNA binding protein with nucleic acid chaperone activity, whereas the ORF2 protein (ORF2p) supplies the enzymatic activities for cDNA synthesis. This article reviews the nucleic acid chaperone properties of ORF1p in the context of L1 retrotransposition.
Collapse
Affiliation(s)
- Sandra L Martin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA.
| |
Collapse
|
45
|
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.
Collapse
Affiliation(s)
- Judith G Levin
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
| | | | | | | |
Collapse
|
46
|
Mirambeau G, Lyonnais S, Gorelick RJ. Features, processing states, and heterologous protein interactions in the modulation of the retroviral nucleocapsid protein function. RNA Biol 2010; 7:724-34. [PMID: 21045549 PMCID: PMC3073331 DOI: 10.4161/rna.7.6.13777] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 09/14/2010] [Accepted: 09/16/2010] [Indexed: 11/19/2022] Open
Abstract
Retroviral nucleocapsid (NC) is central to viral replication. Nucleic acid chaperoning is a key function for NC through the action of its conserved basic amino acids and zinc-finger structures. NC manipulates genomic RNA from its packaging in the producer cell to reverse transcription into the infected host cell. This chaperone function, in conjunction with NC's aggregating properties, is up-modulated by successive NC processing events, from the Gag precursor to the fully mature protein, resulting in the condensation of the nucleocapsid within the capsid shell. Reverse transcription also depends on NC processing, whereas this process provokes NC dissociation from double-stranded DNA, leading to a preintegration complex (PIC), competent for host chromosomal integration. In addition NC interacts with cellular proteins, some of which are involved in viral budding, and also with several viral proteins. All of these properties are reviewed here, focusing on HIV-1 as a paradigmatic reference and highlighting the plasticity of the nucleocapsid architecture.
Collapse
|
47
|
Wu H, Rouzina I, Williams MC. Single-molecule stretching studies of RNA chaperones. RNA Biol 2010; 7:712-23. [PMID: 21045548 PMCID: PMC3073330 DOI: 10.4161/rna.7.6.13776] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 09/15/2010] [Accepted: 09/16/2010] [Indexed: 01/25/2023] Open
Abstract
RNA chaperone proteins play significant roles in diverse biological contexts. The most widely studied RNA chaperones are the retroviral nucleocapsid proteins (NC), also referred to as nucleic acid (NA) chaperones. Surprisingly, the biophysical properties of the NC proteins vary significantly for different viruses, and it appears that HIV-1 NC has optimal NA chaperone activity. In this review we discuss the physical nature of the NA chaperone activity of NC. We conclude that the optimal NA chaperone must saturate NA binding, leading to strong NA aggregation and slight destabilization of all NA duplexes. Finally, rapid kinetics of the chaperone protein interaction with NA is another primary component of its NA chaperone activity. We discuss these characteristics of HIV-1 NC and compare them with those of other NA binding proteins and ligands that exhibit only some characteristics of NA chaperone activity, as studied by single molecule DNA stretching.
Collapse
Affiliation(s)
- Hao Wu
- Department of Physics, Northeastern University, Boston, MA, USA
| | | | | |
Collapse
|
48
|
Abstract
Many non-coding RNAs fold into complex three-dimensional structures, yet the self-assembly of RNA structure is hampered by mispairing, weak tertiary interactions, electrostatic barriers, and the frequent requirement that the 5' and 3' ends of the transcript interact. This rugged free energy landscape for RNA folding means that some RNA molecules in a population rapidly form their native structure, while many others become kinetically trapped in misfolded conformations. Transient binding of RNA chaperone proteins destabilize misfolded intermediates and lower the transition states between conformations, producing a smoother landscape that increases the rate of folding and the probability that a molecule will find the native structure. DEAD-box proteins couple the chemical potential of ATP hydrolysis with repetitive cycles of RNA binding and release, expanding the range of conditions under which they can refold RNA structures.
Collapse
Affiliation(s)
- Sarah A Woodson
- T. C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
49
|
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.
Collapse
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
| |
Collapse
|
50
|
Chaurasiya KR, Paramanathan T, McCauley MJ, Williams MC. Biophysical characterization of DNA binding from single molecule force measurements. Phys Life Rev 2010; 7:299-341. [PMID: 20576476 DOI: 10.1016/j.plrev.2010.06.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 05/19/2010] [Accepted: 05/20/2010] [Indexed: 11/25/2022]
Abstract
Single molecule force spectroscopy is a powerful method that uses the mechanical properties of DNA to explore DNA interactions. Here we describe how DNA stretching experiments quantitatively characterize the DNA binding of small molecules and proteins. Small molecules exhibit diverse DNA binding modes, including binding into the major and minor grooves and intercalation between base pairs of double-stranded DNA (dsDNA). Histones bind and package dsDNA, while other nuclear proteins such as high mobility group proteins bind to the backbone and bend dsDNA. Single-stranded DNA (ssDNA) binding proteins slide along dsDNA to locate and stabilize ssDNA during replication. Other proteins exhibit binding to both dsDNA and ssDNA. Nucleic acid chaperone proteins can switch rapidly between dsDNA and ssDNA binding modes, while DNA polymerases bind both forms of DNA with high affinity at distinct binding sites at the replication fork. Single molecule force measurements quantitatively characterize these DNA binding mechanisms, elucidating small molecule interactions and protein function.
Collapse
Affiliation(s)
- Kathy R Chaurasiya
- Department of Physics, Northeastern University, 111 Dana Research Center, Boston, MA 02115, USA
| | | | | | | |
Collapse
|