1
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Pitchai FNN, Tanner EJ, Khetan N, Vasen G, Levrel C, Kumar AJ, Pandey S, Ordonez T, Barnette P, Spencer D, Jung SY, Glazier J, Thompson C, Harvey-Vera A, Son HI, Son HI, Strathdee SA, Holguin L, Urak R, Burnett J, Burgess W, Busman-Sahay K, Estes JD, Hessell A, Fennessey CM, Keele BF, Haigwood NL, Weinberger LS. Engineered deletions of HIV replicate conditionally to reduce disease in nonhuman primates. Science 2024; 385:eadn5866. [PMID: 39116226 DOI: 10.1126/science.adn5866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 06/06/2024] [Indexed: 08/10/2024]
Abstract
Antiviral therapies with reduced frequencies of administration and high barriers to resistance remain a major goal. For HIV, theories have proposed that viral-deletion variants, which conditionally replicate with a basic reproductive ratio [R0] > 1 (termed "therapeutic interfering particles" or "TIPs"), could parasitize wild-type virus to constitute single-administration, escape-resistant antiviral therapies. We report the engineering of a TIP that, in rhesus macaques, reduces viremia of a highly pathogenic model of HIV by >3log10 following a single intravenous injection. Animal lifespan was significantly extended, TIPs conditionally replicated and were continually detected for >6 months, and sequencing data showed no evidence of viral escape. A single TIP injection also suppressed virus replication in humanized mice and cells from persons living with HIV. These data provide proof of concept for a potential new class of single-administration antiviral therapies.
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Affiliation(s)
- Fathima N Nagoor Pitchai
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
- Gladstone Institute of Virology, University of California, San Francisco, CA, USA
| | - Elizabeth J Tanner
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
- Gladstone Institute of Virology, University of California, San Francisco, CA, USA
| | - Neha Khetan
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
- Gladstone Institute of Virology, University of California, San Francisco, CA, USA
| | - Gustavo Vasen
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
- Gladstone Institute of Virology, University of California, San Francisco, CA, USA
| | - Clara Levrel
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
- Gladstone Institute of Virology, University of California, San Francisco, CA, USA
| | - Arjun J Kumar
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
- Gladstone Institute of Virology, University of California, San Francisco, CA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Shilpi Pandey
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | - Tracy Ordonez
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | - Philip Barnette
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | - David Spencer
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
- Absci Corporation, Vancouver, WA, USA
| | - Seung-Yong Jung
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
| | - Joshua Glazier
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
| | - Cassandra Thompson
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | | | - Hye-In Son
- Global Health Sciences, Department of Medicine, University of California San Diego, La Jolla, CA, USA
- US-Mexico Border Health Commission, Tijuana, Mexico
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR, USA
| | - Hye-In Son
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
| | - Steffanie A Strathdee
- Global Health Sciences, Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Leo Holguin
- Global Health Sciences, Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Ryan Urak
- Center for Gene Therapy, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA, USA
| | - John Burnett
- Center for Gene Therapy, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA, USA
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - William Burgess
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR, USA
| | - Kathleen Busman-Sahay
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR, USA
| | - Jacob D Estes
- Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR, USA
- Faculty of Health, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- School of Health and Biomedical Sciences College of Science, Engineering and Health RMIT University, Melbourne, Australia
| | - Ann Hessell
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | - Christine M Fennessey
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Brandon F Keele
- AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Nancy L Haigwood
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | - Leor S Weinberger
- Gladstone Center for Cell Circuitry, University of California, San Francisco, CA, USA
- Gladstone Institute of Virology, University of California, San Francisco, CA, USA
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA
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2
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Martin EW, Iserman C, Olety B, Mitrea DM, Klein IA. Biomolecular Condensates as Novel Antiviral Targets. J Mol Biol 2024; 436:168380. [PMID: 38061626 DOI: 10.1016/j.jmb.2023.168380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 11/23/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
Viral infections pose a significant health risk worldwide. There is a pressing need for more effective antiviral drugs to combat emerging novel viruses and the reemergence of previously controlled viruses. Biomolecular condensates are crucial for viral replication and are promising targets for novel antiviral therapies. Herein, we review the role of biomolecular condensates in the viral replication cycle and discuss novel strategies to leverage condensate biology for antiviral drug discovery. Biomolecular condensates may also provide an opportunity to develop antivirals that are broad-spectrum or less prone to acquired drug resistance.
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3
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Lei X, Gonçalves-Carneiro D, Zang TM, Bieniasz PD. Initiation of HIV-1 Gag lattice assembly is required for recognition of the viral genome packaging signal. eLife 2023; 12:e83548. [PMID: 36688533 PMCID: PMC9908077 DOI: 10.7554/elife.83548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 01/20/2023] [Indexed: 01/24/2023] Open
Abstract
The encapsidation of HIV-1 gRNA into virions is enabled by the binding of the nucleocapsid (NC) domain of the HIV-1 Gag polyprotein to the structured viral RNA packaging signal (Ψ) at the 5' end of the viral genome. However, the subcellular location and oligomeric status of Gag during the initial Gag-Ψ encounter remain uncertain. Domains other than NC, such as capsid (CA), may therefore indirectly affect RNA recognition. To investigate the contribution of Gag domains to Ψ recognition in a cellular environment, we performed protein-protein crosslinking and protein-RNA crosslinking immunoprecipitation coupled with sequencing (CLIP-seq) experiments. We demonstrate that NC alone does not bind specifically to Ψ in living cells, whereas full-length Gag and a CANC subdomain bind to Ψ with high specificity. Perturbation of the Ψ RNA structure or NC zinc fingers affected CANC:Ψ binding specificity. Notably, CANC variants with substitutions that disrupt CA:CA dimer, trimer, or hexamer interfaces in the immature Gag lattice also affected RNA binding, and mutants that were unable to assemble a nascent Gag lattice were unable to specifically bind to Ψ. Artificially multimerized NC domains did not specifically bind Ψ. CA variants with substitutions in inositol phosphate coordinating residues that prevent CA hexamerization were also deficient in Ψ binding and second-site revertant mutants that restored CA assembly also restored specific binding to Ψ. Overall, these data indicate that the correct assembly of a nascent immature CA lattice is required for the specific interaction between Gag and Ψ in cells.
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Affiliation(s)
- Xiao Lei
- Laboratory of Retrovirology, Rockefeller UniversityNew YorkUnited States
| | | | - Trinity M Zang
- Laboratory of Retrovirology, Rockefeller UniversityNew YorkUnited States
- Howard Hughes Medical Institute, The Rockefeller UniversityNew York, New YorkUnited States
| | - Paul D Bieniasz
- Laboratory of Retrovirology, Rockefeller UniversityNew YorkUnited States
- Howard Hughes Medical Institute, The Rockefeller UniversityNew York, New YorkUnited States
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4
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Wolff JH, Mikkelsen JG. Delivering genes with human immunodeficiency virus-derived vehicles: still state-of-the-art after 25 years. J Biomed Sci 2022; 29:79. [PMID: 36209077 PMCID: PMC9548131 DOI: 10.1186/s12929-022-00865-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 09/29/2022] [Indexed: 11/10/2022] Open
Abstract
Viruses are naturally endowed with the capacity to transfer genetic material between cells. Following early skepticism, engineered viruses have been used to transfer genetic information into thousands of patients, and genetic therapies are currently attracting large investments. Despite challenges and severe adverse effects along the way, optimized technologies and improved manufacturing processes are driving gene therapy toward clinical translation. Fueled by the outbreak of AIDS in the 1980s and the accompanying focus on human immunodeficiency virus (HIV), lentiviral vectors derived from HIV have grown to become one of the most successful and widely used vector technologies. In 2022, this vector technology has been around for more than 25 years. Here, we celebrate the anniversary by portraying the vector system and its intriguing properties. We dive into the technology itself and recapitulate the use of lentiviral vectors for ex vivo gene transfer to hematopoietic stem cells and for production of CAR T-cells. Furthermore, we describe the adaptation of lentiviral vectors for in vivo gene delivery and cover the important contribution of lentiviral vectors to basic molecular research including their role as carriers of CRISPR genome editing technologies. Last, we dwell on the emerging capacity of lentiviral particles to package and transfer foreign proteins.
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Affiliation(s)
- Jonas Holst Wolff
- Department of Biomedicine, Aarhus University, Høegh-Guldbergs Gade 10, 8000, Aarhus C, Denmark
| | - Jacob Giehm Mikkelsen
- Department of Biomedicine, Aarhus University, Høegh-Guldbergs Gade 10, 8000, Aarhus C, Denmark.
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5
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Ding P, Summers MF. Sequestering the 5′‐cap for viral RNA packaging. Bioessays 2022; 44:e2200104. [PMID: 36101513 DOI: 10.1002/bies.202200104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/28/2022] [Accepted: 08/31/2022] [Indexed: 11/11/2022]
Abstract
Many viruses evolved mechanisms for capping the 5'-ends of their plus-strand RNAs as a means of hijacking the eukaryotic messenger RNA (mRNA) splicing/translation machinery. Although capping is critical for replication, the RNAs of these viruses have other essential functions including their requirement to be packaged as either genomes or pre-genomes into progeny viruses. Recent studies indicate that human immunodeficiency virus type-1 (HIV-1) RNAs are segregated between splicing/translation and packaging functions by a mechanism that involves structural sequestration of the 5'-cap. Here, we examined studies reported for other viruses and retrotransposons that require both selective packaging of their RNAs and 5'-RNA capping for host-mediated translation. Our findings suggest that viruses and retrotransposons have evolved multiple mechanisms to control 5'-cap accessibility, consistent with the hypothesis that removal or sequestration of the 5' cap enables packageable RNAs to avoid capture by the cellular RNA processing and translation machinery.
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Affiliation(s)
- Pengfei Ding
- Department of Chemistry and Biochemistry and Howard Hughes Medical Institute University of Maryland Baltimore County Baltimore Maryland USA
| | - Michael F. Summers
- Department of Chemistry and Biochemistry and Howard Hughes Medical Institute University of Maryland Baltimore County Baltimore Maryland USA
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6
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Hanson HM, Willkomm NA, Yang H, Mansky LM. Human Retrovirus Genomic RNA Packaging. Viruses 2022; 14:1094. [PMID: 35632835 PMCID: PMC9142903 DOI: 10.3390/v14051094] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/12/2022] [Accepted: 05/14/2022] [Indexed: 02/07/2023] Open
Abstract
Two non-covalently linked copies of the retrovirus genome are specifically recruited to the site of virus particle assembly and packaged into released particles. Retroviral RNA packaging requires RNA export of the unspliced genomic RNA from the nucleus, translocation of the genome to virus assembly sites, and specific interaction with Gag, the main viral structural protein. While some aspects of the RNA packaging process are understood, many others remain poorly understood. In this review, we provide an update on recent advancements in understanding the mechanism of RNA packaging for retroviruses that cause disease in humans, i.e., HIV-1, HIV-2, and HTLV-1, as well as advances in the understanding of the details of genomic RNA nuclear export, genome translocation to virus assembly sites, and genomic RNA dimerization.
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Affiliation(s)
- Heather M. Hanson
- Molecular, Cellular, Developmental Biology, and Genetics Graduate Program, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA;
- Institute for Molecular Virology, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA; (N.A.W.); (H.Y.)
| | - Nora A. Willkomm
- Institute for Molecular Virology, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA; (N.A.W.); (H.Y.)
- DDS-PhD Dual Degree Program, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
| | - Huixin Yang
- Institute for Molecular Virology, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA; (N.A.W.); (H.Y.)
- Comparative Molecular Biosciences Graduate Program, University of Minnesota—Twin Cities, St. Paul, MN 55455, USA
| | - Louis M. Mansky
- Molecular, Cellular, Developmental Biology, and Genetics Graduate Program, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA;
- Institute for Molecular Virology, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA; (N.A.W.); (H.Y.)
- DDS-PhD Dual Degree Program, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Comparative Molecular Biosciences Graduate Program, University of Minnesota—Twin Cities, St. Paul, MN 55455, USA
- Masonic Cancer Center, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Division of Basic Sciences, School of Dentistry, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
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7
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Bernacchi S. Visualization of Retroviral Gag-Genomic RNA Cellular Interactions Leading to Genome Encapsidation and Viral Assembly: An Overview. Viruses 2022; 14:324. [PMID: 35215917 PMCID: PMC8876502 DOI: 10.3390/v14020324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/25/2022] [Accepted: 02/03/2022] [Indexed: 11/16/2022] Open
Abstract
Retroviruses must selectively recognize their unspliced RNA genome (gRNA) among abundant cellular and spliced viral RNAs to assemble into newly formed viral particles. Retroviral gRNA packaging is governed by Gag precursors that also orchestrate all the aspects of viral assembly. Retroviral life cycles, and especially the HIV-1 one, have been previously extensively analyzed by several methods, most of them based on molecular biology and biochemistry approaches. Despite these efforts, the spatio-temporal mechanisms leading to gRNA packaging and viral assembly are only partially understood. Nevertheless, in these last decades, progress in novel bioimaging microscopic approaches (as FFS, FRAP, TIRF, and wide-field microscopy) have allowed for the tracking of retroviral Gag and gRNA in living cells, thus providing important insights at high spatial and temporal resolution of the events regulating the late phases of the retroviral life cycle. Here, the implementation of these recent bioimaging tools based on highly performing strategies to label fluorescent macromolecules is described. This report also summarizes recent gains in the current understanding of the mechanisms employed by retroviral Gag polyproteins to regulate molecular mechanisms enabling gRNA packaging and the formation of retroviral particles, highlighting variations and similarities among the different retroviruses.
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Affiliation(s)
- Serena Bernacchi
- Architecture et Réactivité de l'ARN-UPR 9002, IBMC, CNRS, Université de Strasbourg, F-67000 Strasbourg, France
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8
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Durand S, Seigneuret F, Burlaud-Gaillard J, Lemoine R, Tassi MF, Moreau A, Mougel M, Roingeard P, Tauber C, de Rocquigny H. Quantitative analysis of the formation of nucleoprotein complexes between HIV-1 Gag protein and genomic RNA using transmission electron microscopy. J Biol Chem 2022; 298:101500. [PMID: 34929171 PMCID: PMC8760521 DOI: 10.1016/j.jbc.2021.101500] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 12/05/2021] [Indexed: 01/06/2023] Open
Abstract
In HIV, the polyprotein precursor Gag orchestrates the formation of the viral capsid. In the current view of this viral assembly, Gag forms low-order oligomers that bind to the viral genomic RNA triggering the formation of high-ordered ribonucleoprotein complexes. However, this assembly model was established using biochemical or imaging methods that do not describe the cellular location hosting Gag-gRNA complex nor distinguish gRNA packaging in single particles. Here, we studied the intracellular localization of these complexes by electron microscopy and monitored the distances between the two partners by morphometric analysis of gold beads specifically labeling Gag and gRNA. We found that formation of these viral clusters occurred shortly after the nuclear export of the gRNA. During their transport to the plasma membrane, the distance between Gag and gRNA decreases together with an increase of gRNA packaging. Point mutations in the zinc finger patterns of the nucleocapsid domain of Gag caused an increase in the distance between Gag and gRNA as well as a sharp decrease of gRNA packaged into virions. Finally, we show that removal of stem loop 1 of the 5'-untranslated region does not interfere with gRNA packaging, whereas combined with the removal of stem loop 3 is sufficient to decrease but not abolish Gag-gRNA cluster formation and gRNA packaging. In conclusion, this morphometric analysis of Gag-gRNA cluster formation sheds new light on HIV-1 assembly that can be used to describe at nanoscale resolution other viral assembly steps involving RNA or protein-protein interactions.
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Affiliation(s)
- Stéphanie Durand
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Florian Seigneuret
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Julien Burlaud-Gaillard
- Microscopy IBiSA Platform, PPF ASB, University of Tours and CHRU of Tours, Tours Cedex 1, France
| | - Roxane Lemoine
- B Cell Ressources Platform, EA4245 "Transplantation, Immunology and Inflammation", University of Tours, Tours Cedex 1, France
| | - Marc-Florent Tassi
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Alain Moreau
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Marylène Mougel
- Équipe R2D2 Retroviral RNA Dynamics and Delivery, IRIM, CNRS UMR9004, University of Montpellier, Montpellier, France
| | - Philippe Roingeard
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France; Microscopy IBiSA Platform, PPF ASB, University of Tours and CHRU of Tours, Tours Cedex 1, France
| | - Clovis Tauber
- UMR U1253 iBrain, Inserm, University of Tours, Tours Cedex 1, France
| | - Hugues de Rocquigny
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France.
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9
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Selective packaging of HIV-1 RNA genome is guided by the stability of 5' untranslated region polyA stem. Proc Natl Acad Sci U S A 2021; 118:2114494118. [PMID: 34873042 DOI: 10.1073/pnas.2114494118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2021] [Indexed: 01/08/2023] Open
Abstract
To generate infectious virus, HIV-1 must package two copies of its full-length RNA into particles. HIV-1 transcription initiates from multiple, neighboring sites, generating RNA species that only differ by a few nucleotides at the 5' end, including those with one (1G) or three (3G) 5' guanosines. Strikingly, 1G RNA is preferentially packaged into virions over 3G RNA. We investigated how HIV-1 distinguishes between these nearly identical RNAs using in-gel chemical probing combined with recently developed computational tools for determining RNA conformational ensembles, as well as cell-based assays to quantify the efficiency of RNA packaging into viral particles. We found that 1G and 3G RNAs fold into distinct structural ensembles. The 1G RNA, but not the 3G RNA, primarily adopts conformations with an intact polyA stem, exposed dimerization initiation site, and multiple, unpaired guanosines known to mediate Gag binding. Furthermore, we identified mutants that exhibited altered genome selectivity and packaged 3G RNA efficiently. In these mutants, both 1G and 3G RNAs fold into similar conformational ensembles, such that they can no longer be distinguished. Our findings demonstrate that polyA stem stability guides RNA-packaging selectivity. These studies also uncover the mechanism by which HIV-1 selects its genome for packaging: 1G RNA is preferentially packaged because it exposes structural elements that promote RNA dimerization and Gag binding.
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10
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D’Souza AR, Jayaraman D, Long Z, Zeng J, Prestwood LJ, Chan C, Kappei D, Lever AML, Kenyon JC. HIV-1 Packaging Visualised by In-Gel SHAPE. Viruses 2021; 13:v13122389. [PMID: 34960658 PMCID: PMC8707378 DOI: 10.3390/v13122389] [Citation(s) in RCA: 4] [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: 10/22/2021] [Revised: 11/21/2021] [Accepted: 11/23/2021] [Indexed: 11/16/2022] Open
Abstract
HIV-1 packages two copies of its gRNA into virions via an interaction with the viral structural protein Gag. Both copies and their native RNA structure are essential for virion infectivity. The precise stepwise nature of the packaging process has not been resolved. This is largely due to a prior lack of structural techniques that follow RNA structural changes within an RNA-protein complex. Here, we apply the in-gel SHAPE (selective 2'OH acylation analysed by primer extension) technique to study the initiation of HIV-1 packaging, examining the interaction between the packaging signal RNA and the Gag polyprotein, and compare it with that of the NC domain of Gag alone. Our results imply interactions between Gag and monomeric packaging signal RNA in switching the RNA conformation into a dimerisation-competent structure, and show that the Gag-dimer complex then continues to stabilise. These data provide a novel insight into how HIV-1 regulates the translation and packaging of its genome.
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Affiliation(s)
- Aaron R. D’Souza
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (A.R.D.); (D.J.)
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore; (C.C.); (D.K.)
| | - Dhivya Jayaraman
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (A.R.D.); (D.J.)
| | - Ziqi Long
- Department of Medicine, University of Cambridge, Level 5 Addenbrookes Hospital, Cambridge CB2 0QQ, UK; (Z.L.); (J.Z.); (L.J.P.)
| | - Jingwei Zeng
- Department of Medicine, University of Cambridge, Level 5 Addenbrookes Hospital, Cambridge CB2 0QQ, UK; (Z.L.); (J.Z.); (L.J.P.)
| | - Liam J. Prestwood
- Department of Medicine, University of Cambridge, Level 5 Addenbrookes Hospital, Cambridge CB2 0QQ, UK; (Z.L.); (J.Z.); (L.J.P.)
| | - Charlene Chan
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore; (C.C.); (D.K.)
| | - Dennis Kappei
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore; (C.C.); (D.K.)
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
- NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Andrew M. L. Lever
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; (A.R.D.); (D.J.)
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore; (C.C.); (D.K.)
- Department of Medicine, University of Cambridge, Level 5 Addenbrookes Hospital, Cambridge CB2 0QQ, UK; (Z.L.); (J.Z.); (L.J.P.)
- Correspondence: (A.M.L.L.); (J.C.K.); Tel.: +44-(0)1-2237-47308 (J.C.K.)
| | - Julia C. Kenyon
- Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore; (C.C.); (D.K.)
- Department of Medicine, University of Cambridge, Level 5 Addenbrookes Hospital, Cambridge CB2 0QQ, UK; (Z.L.); (J.Z.); (L.J.P.)
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
- Homerton College, University of Cambridge, Cambridge CB2 8PH, UK
- Correspondence: (A.M.L.L.); (J.C.K.); Tel.: +44-(0)1-2237-47308 (J.C.K.)
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11
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Liu S, Koneru PC, Li W, Pathirage C, Engelman AN, Kvaratskhelia M, Musier-Forsyth K. HIV-1 integrase binding to genomic RNA 5'-UTR induces local structural changes in vitro and in virio. Retrovirology 2021; 18:37. [PMID: 34809662 PMCID: PMC8609798 DOI: 10.1186/s12977-021-00582-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 11/03/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND During HIV-1 maturation, Gag and Gag-Pol polyproteins are proteolytically cleaved and the capsid protein polymerizes to form the honeycomb capsid lattice. HIV-1 integrase (IN) binds the viral genomic RNA (gRNA) and impairment of IN-gRNA binding leads to mis-localization of the nucleocapsid protein (NC)-condensed viral ribonucleoprotein complex outside the capsid core. IN and NC were previously demonstrated to bind to the gRNA in an orthogonal manner in virio; however, the effect of IN binding alone or simultaneous binding of both proteins on gRNA structure is not yet well understood. RESULTS Using crosslinking-coupled selective 2'-hydroxyl acylation analyzed by primer extension (XL-SHAPE), we characterized the interaction of IN and NC with the HIV-1 gRNA 5'-untranslated region (5'-UTR). NC preferentially bound to the packaging signal (Psi) and a UG-rich region in U5, irrespective of the presence of IN. IN alone also bound to Psi but pre-incubation with NC largely abolished this interaction. In contrast, IN specifically bound to and affected the nucleotide (nt) dynamics of the apical loop of the transactivation response element (TAR) and the polyA hairpin even in the presence of NC. SHAPE probing of the 5'-UTR RNA in virions produced from allosteric IN inhibitor (ALLINI)-treated cells revealed that while the global secondary structure of the 5'-UTR remained unaltered, the inhibitor treatment induced local reactivity differences, including changes in the apical loop of TAR that are consistent with the in vitro results. CONCLUSIONS Overall, the binding interactions of NC and IN with the 5'-UTR are largely orthogonal in vitro. This study, together with previous probing experiments, suggests that IN and NC binding in vitro and in virio lead to only local structural changes in the regions of the 5'-UTR probed here. Accordingly, disruption of IN-gRNA binding by ALLINI treatment results in local rather than global secondary structure changes of the 5'-UTR in eccentric virus particles.
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Affiliation(s)
- Shuohui Liu
- grid.261331.40000 0001 2285 7943Department of Chemistry and Biochemistry, Centers for RNA Biology and Retroviral Research, The Ohio State University, Columbus, OH USA
| | - Pratibha C. Koneru
- grid.430503.10000 0001 0703 675XDivision of Infectious Diseases, School of Medicine, University of Colorado, Aurora, CO USA
| | - Wen Li
- grid.65499.370000 0001 2106 9910Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA USA ,grid.38142.3c000000041936754XDepartment of Medicine, Harvard Medical School, Boston, MA USA
| | - Chathuri Pathirage
- grid.261331.40000 0001 2285 7943Department of Chemistry and Biochemistry, Centers for RNA Biology and Retroviral Research, The Ohio State University, Columbus, OH USA
| | - Alan N. Engelman
- grid.65499.370000 0001 2106 9910Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA USA ,grid.38142.3c000000041936754XDepartment of Medicine, Harvard Medical School, Boston, MA USA
| | - Mamuka Kvaratskhelia
- grid.430503.10000 0001 0703 675XDivision of Infectious Diseases, School of Medicine, University of Colorado, Aurora, CO USA
| | - Karin Musier-Forsyth
- grid.261331.40000 0001 2285 7943Department of Chemistry and Biochemistry, Centers for RNA Biology and Retroviral Research, The Ohio State University, Columbus, OH USA
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12
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5'-Cap sequestration is an essential determinant of HIV-1 genome packaging. Proc Natl Acad Sci U S A 2021; 118:2112475118. [PMID: 34493679 PMCID: PMC8449379 DOI: 10.1073/pnas.2112475118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/05/2021] [Indexed: 12/14/2022] Open
Abstract
HIV-1 selectively packages two copies of its 5'-capped RNA genome (gRNA) during virus assembly, a process mediated by the nucleocapsid (NC) domain of the viral Gag polyprotein and encapsidation signals located within the dimeric 5' leader of the viral RNA. Although residues within the leader that promote packaging have been identified, the determinants of authentic packaging fidelity and efficiency remain unknown. Here, we show that a previously characterized 159-nt region of the leader that possesses all elements required for RNA dimerization, high-affinity NC binding, and packaging in a noncompetitive RNA packaging assay (ΨCES) is unexpectedly poorly packaged when assayed in competition with the intact 5' leader. ΨCES lacks a 5'-tandem hairpin element that sequesters the 5' cap, suggesting that cap sequestration may be important for packaging. Consistent with this hypothesis, mutations within the intact leader that expose the cap without disrupting RNA structure or NC binding abrogated RNA packaging, and genetic addition of a 5' ribozyme to ΨCES to enable cotranscriptional shedding of the 5' cap promoted ΨCES-mediated RNA packaging to wild-type levels. Additional mutations that either block dimerization or eliminate subsets of NC binding sites substantially attenuated competitive packaging. Our studies indicate that packaging is achieved by a bipartite mechanism that requires both sequestration of the 5' cap and exposure of NC binding sites that reside fully within the ΨCES region of the dimeric leader. We speculate that cap sequestration prevents irreversible capture by the cellular RNA processing and translation machinery, a mechanism likely employed by other viruses that package 5'-capped RNA genomes.
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13
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RNA Structures and Their Role in Selective Genome Packaging. Viruses 2021; 13:v13091788. [PMID: 34578369 PMCID: PMC8472981 DOI: 10.3390/v13091788] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 12/13/2022] Open
Abstract
To generate infectious viral particles, viruses must specifically select their genomic RNA from milieu that contains a complex mixture of cellular or non-genomic viral RNAs. In this review, we focus on the role of viral encoded RNA structures in genome packaging. We first discuss how packaging signals are constructed from local and long-range base pairings within viral genomes, as well as inter-molecular interactions between viral and host RNAs. Then, how genome packaging is regulated by the biophysical properties of RNA. Finally, we examine the impact of RNA packaging signals on viral evolution.
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14
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Cole B, Lambrechts L, Gantner P, Noppe Y, Bonine N, Witkowski W, Chen L, Palmer S, Mullins JI, Chomont N, Pardons M, Vandekerckhove L. In-depth single-cell analysis of translation-competent HIV-1 reservoirs identifies cellular sources of plasma viremia. Nat Commun 2021; 12:3727. [PMID: 34140517 PMCID: PMC8211655 DOI: 10.1038/s41467-021-24080-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/22/2021] [Indexed: 02/07/2023] Open
Abstract
Clonal expansion of HIV-infected cells contributes to the long-term persistence of the HIV reservoir in ART-suppressed individuals. However, the contribution from cell clones that harbor inducible proviruses to plasma viremia is poorly understood. Here, we describe a single-cell approach to simultaneously sequence the TCR, integration sites and proviral genomes from translation-competent reservoir cells, called STIP-Seq. By applying this approach to blood samples from eight participants, we show that the translation-competent reservoir mainly consists of proviruses with short deletions at the 5'-end of the genome, often involving the major splice donor site. TCR and integration site sequencing reveal that cell clones with predicted pathogen-specificity can harbor inducible proviruses integrated into cancer-related genes. Furthermore, we find several matches between proviruses retrieved with STIP-Seq and plasma viruses obtained during ART and upon treatment interruption, suggesting that STIP-Seq can capture clones that are responsible for low-level viremia or viral rebound.
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Affiliation(s)
- Basiel Cole
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, Ghent, Belgium
| | - Laurens Lambrechts
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, Ghent, Belgium
- BioBix, Department of Data Analysis and Mathematical Modelling, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Pierre Gantner
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, Canada
| | - Ytse Noppe
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, Ghent, Belgium
| | - Noah Bonine
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, Ghent, Belgium
- BioBix, Department of Data Analysis and Mathematical Modelling, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Wojciech Witkowski
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, Ghent, Belgium
| | - Lennie Chen
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Sarah Palmer
- Centre for Virus Research, The Westmead Institute for Medical Research, The University of Sydney, Sydney, NSW, Australia
| | - James I Mullins
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Global Health, University of Washington, Seattle, WA, USA
| | - Nicolas Chomont
- Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, QC, Canada
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada
| | - Marion Pardons
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, Ghent, Belgium
| | - Linos Vandekerckhove
- HIV Cure Research Center, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, Ghent, Belgium.
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15
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Knoener R, Evans E, Becker JT, Scalf M, Benner B, Sherer NM, Smith LM. Identification of host proteins differentially associated with HIV-1 RNA splice variants. eLife 2021; 10:e62470. [PMID: 33629952 PMCID: PMC7906601 DOI: 10.7554/elife.62470] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/27/2021] [Indexed: 12/12/2022] Open
Abstract
HIV-1 generates unspliced (US), partially spliced (PS), and completely spliced (CS) classes of RNAs, each playing distinct roles in viral replication. Elucidating their host protein 'interactomes' is crucial to understanding virus-host interplay. Here, we present HyPR-MSSV for isolation of US, PS, and CS transcripts from a single population of infected CD4+ T-cells and mass spectrometric identification of their in vivo protein interactomes. Analysis revealed 212 proteins differentially associated with the unique RNA classes, including preferential association of regulators of RNA stability with US and PS transcripts and, unexpectedly, mitochondria-linked proteins with US transcripts. Remarkably, >80 of these factors screened by siRNA knockdown impacted HIV-1 gene expression. Fluorescence microscopy confirmed several to co-localize with HIV-1 US RNA and exhibit changes in abundance and/or localization over the course of infection. This study validates HyPR-MSSV for discovery of viral splice variant protein interactomes and provides an unprecedented resource of factors and pathways likely important to HIV-1 replication.
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Affiliation(s)
- Rachel Knoener
- Department of Chemistry, University of WisconsinMadisonUnited States
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Edward Evans
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Jordan T Becker
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Mark Scalf
- Department of Chemistry, University of WisconsinMadisonUnited States
| | - Bayleigh Benner
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Nathan M Sherer
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of WisconsinMadisonUnited States
| | - Lloyd M Smith
- Department of Chemistry, University of WisconsinMadisonUnited States
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16
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Boyd PS, Brown JB, Brown JD, Catazaro J, Chaudry I, Ding P, Dong X, Marchant J, O’Hern CT, Singh K, Swanson C, Summers MF, Yasin S. NMR Studies of Retroviral Genome Packaging. Viruses 2020; 12:v12101115. [PMID: 33008123 PMCID: PMC7599994 DOI: 10.3390/v12101115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/18/2020] [Accepted: 09/26/2020] [Indexed: 12/03/2022] Open
Abstract
Nearly all retroviruses selectively package two copies of their unspliced RNA genomes from a cellular milieu that contains a substantial excess of non-viral and spliced viral RNAs. Over the past four decades, combinations of genetic experiments, phylogenetic analyses, nucleotide accessibility mapping, in silico RNA structure predictions, and biophysical experiments were employed to understand how retroviral genomes are selected for packaging. Genetic studies provided early clues regarding the protein and RNA elements required for packaging, and nucleotide accessibility mapping experiments provided insights into the secondary structures of functionally important elements in the genome. Three-dimensional structural determinants of packaging were primarily derived by nuclear magnetic resonance (NMR) spectroscopy. A key advantage of NMR, relative to other methods for determining biomolecular structure (such as X-ray crystallography), is that it is well suited for studies of conformationally dynamic and heterogeneous systems—a hallmark of the retrovirus packaging machinery. Here, we review advances in understanding of the structures, dynamics, and interactions of the proteins and RNA elements involved in retroviral genome selection and packaging that are facilitated by NMR.
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17
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Mouhand A, Pasi M, Catala M, Zargarian L, Belfetmi A, Barraud P, Mauffret O, Tisné C. Overview of the Nucleic-Acid Binding Properties of the HIV-1 Nucleocapsid Protein in Its Different Maturation States. Viruses 2020; 12:v12101109. [PMID: 33003650 PMCID: PMC7601788 DOI: 10.3390/v12101109] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/23/2020] [Accepted: 09/26/2020] [Indexed: 12/17/2022] Open
Abstract
HIV-1 Gag polyprotein orchestrates the assembly of viral particles. Its C-terminus consists of the nucleocapsid (NC) domain that interacts with nucleic acids, and p1 and p6, two unstructured regions, p6 containing the motifs to bind ALIX, the cellular ESCRT factor TSG101 and the viral protein Vpr. The processing of Gag by the viral protease subsequently liberates NCp15 (NC-p1-p6), NCp9 (NC-p1) and NCp7, NCp7 displaying the optimal chaperone activity of nucleic acids. This review focuses on the nucleic acid binding properties of the NC domain in the different maturation states during the HIV-1 viral cycle.
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Affiliation(s)
- Assia Mouhand
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Marco Pasi
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Marjorie Catala
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Loussiné Zargarian
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Anissa Belfetmi
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
| | - Pierre Barraud
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
| | - Olivier Mauffret
- Laboratoire de Biologie et de Pharmacologie Appliquée (LBPA), UMR 8113 CNRS, Institut D’Alembert, École Normale Supérieure Paris-Saclay, Université Paris-Saclay, 4, Avenue des Sciences, 91190 Gif sur Yvette, France; (M.P.); (L.Z.); (A.B.)
- Correspondence: (O.M.); (C.T.)
| | - Carine Tisné
- Expression Génétique Microbienne, UMR 8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique (IBPC), 75005 Paris, France; (A.M.); (M.C.); (P.B.)
- Correspondence: (O.M.); (C.T.)
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18
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Vamva E, Lever AML, Vink CA, Kenyon JC. Development of a Novel Competitive qRT-PCR Assay to Measure Relative Lentiviral Packaging Efficiency. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 19:307-319. [PMID: 33145367 PMCID: PMC7581820 DOI: 10.1016/j.omtm.2020.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 09/17/2020] [Indexed: 11/25/2022]
Abstract
Third-generation HIV-1-derived lentiviral vectors are successfully used as therapeutic agents in various clinical applications. To further promote their use, we attempted to enhance vector infectivity by targeting the dimerization and packaging properties of the RNA transfer vector based on the premise that these two processes are tightly linked. We rationally designed mutant vectors to favor the dimeric conformation, potentially enhancing genome packaging. Initial assessments using standard assays generated outputs of variable reproducibility, sometimes with conflicting results. Therefore, we developed a novel competitive qRT-PCR assay in a co-transfection setting to measure the relative packaging efficiencies of wild-type and mutant transfer vectors. Here we report the effect of the dimerization-stabilizing mutations on infectious and physical titers of lentiviral vectors together with their packaging efficiency, measured using our novel assay. Enhancing dimerization did not automatically lead to better vector RNA packaging, suggesting that, for vector functionality, sufficient flexibility of the RNA to adopt different conformations is more important than the dimerization capacity. Our novel competitive qPCR assay enables a more stringent analysis of RNA packaging efficiency, allowing a much more precise understanding of the links between RNA structure, packaging, and infectious titers that will be invaluable for future vector development.
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Affiliation(s)
- Eirini Vamva
- University of Cambridge Department of Medicine, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK.,GlaxoSmithKline, Gunnels Wood Road, Stevenage SG1 2NY, UK
| | - Andrew M L Lever
- University of Cambridge Department of Medicine, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK.,Yong Loo Lin School of Medicine, 1E Kent Ridge Road, Singapore 119228, Singapore
| | - Conrad A Vink
- GlaxoSmithKline, Gunnels Wood Road, Stevenage SG1 2NY, UK
| | - Julia C Kenyon
- University of Cambridge Department of Medicine, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK.,Yong Loo Lin School of Medicine, 1E Kent Ridge Road, Singapore 119228, Singapore.,Homerton College, Hills Road, Cambridge, CB2 8PH, UK
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19
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Boutant E, Bonzi J, Anton H, Nasim MB, Cathagne R, Réal E, Dujardin D, Carl P, Didier P, Paillart JC, Marquet R, Mély Y, de Rocquigny H, Bernacchi S. Zinc Fingers in HIV-1 Gag Precursor Are Not Equivalent for gRNA Recruitment at the Plasma Membrane. Biophys J 2020; 119:419-433. [PMID: 32574557 PMCID: PMC7376094 DOI: 10.1016/j.bpj.2020.05.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/15/2020] [Accepted: 05/06/2020] [Indexed: 01/16/2023] Open
Abstract
The human immunodeficiency virus type 1 Gag precursor specifically selects the unspliced viral genomic RNA (gRNA) from the bulk of cellular and spliced viral RNAs via its nucleocapsid (NC) domain and drives gRNA encapsidation at the plasma membrane (PM). To further identify the determinants governing the intracellular trafficking of Gag-gRNA complexes and their accumulation at the PM, we compared, in living and fixed cells, the interactions between gRNA and wild-type Gag or Gag mutants carrying deletions in NC zinc fingers (ZFs) or a nonmyristoylated version of Gag. Our data showed that the deletion of both ZFs simultaneously or the complete NC domain completely abolished intracytoplasmic Gag-gRNA interactions. Deletion of either ZF delayed the delivery of gRNA to the PM but did not prevent Gag-gRNA interactions in the cytoplasm, indicating that the two ZFs display redundant roles in this respect. However, ZF2 played a more prominent role than ZF1 in the accumulation of the ribonucleoprotein complexes at the PM. Finally, the myristate group, which is mandatory for anchoring the complexes at the PM, was found to be dispensable for the association of Gag with the gRNA in the cytosol.
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Affiliation(s)
- Emmanuel Boutant
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France.
| | - Jeremy Bonzi
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Halina Anton
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Maaz Bin Nasim
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Raphael Cathagne
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Eléonore Réal
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Denis Dujardin
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Philippe Carl
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Pascal Didier
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Jean-Christophe Paillart
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Roland Marquet
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Yves Mély
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Hugues de Rocquigny
- Morphogenèse et Antigénicité du VIH et des Virus des Hépatites, Inserm - U1259 MAVIVH, Tours, France.
| | - Serena Bernacchi
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France.
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20
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Identification of the initial nucleocapsid recognition element in the HIV-1 RNA packaging signal. Proc Natl Acad Sci U S A 2020; 117:17737-17746. [PMID: 32647061 PMCID: PMC7395439 DOI: 10.1073/pnas.2008519117] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Understanding the molecular determinants of retroviral genome packaging is important for drug discovery and development of vectors for gene delivery. We show that the HIV-1 leader, which contains the RNA elements necessary for genome packaging, binds approximately two dozen copies of the cognate NC protein with affinities ranging from ∼40 nM to 1.4 µM. Binding to the four highest-affinity “initial” binding sites occurs with endothermic energetics attributed to NC-induced localized RNA melting. Mutations that stabilize these sites inhibit NC binding in vitro and RNA packaging in transfected cells. A small-molecule inhibitor of RNA packaging binds specifically to the initial NC binding sites and stabilizes the RNA structure. Our findings identify a potential RNA Achilles’ heel for HIV therapeutic development. Selective packaging of the HIV-1 genome during virus assembly is mediated by interactions between the dimeric 5ʹ-leader of the unspliced viral RNA and the nucleocapsid (NC) domains of a small number of assembling viral Gag polyproteins. Here, we show that the dimeric 5′-leader contains more than two dozen NC binding sites with affinities ranging from 40 nM to 1.4 μM, and that all high-affinity sites (Kd ≲ 400 nM) reside within a ∼150-nt region of the leader sufficient to promote RNA packaging (core encapsidation signal, ΨCES). The four initial binding sites with highest affinity reside near two symmetrically equivalent three-way junction structures. Unlike the other high-affinity sites, which bind NC with exothermic energetics, binding to these sites occurs endothermically due to concomitant unwinding of a weakly base-paired [UUUU]:[GGAG] helical element. Mutations that stabilize base pairing within this element eliminate NC binding to this site and severely impair RNA packaging into virus-like particles. NMR studies reveal that a recently discovered small-molecule inhibitor of HIV-1 RNA packaging that appears to function by stabilizing the structure of the leader binds directly to the [UUUU]:[GGAG] helix. Our findings suggest a sequential NC binding mechanism for Gag-genome assembly and identify a potential RNA Achilles’ heel to which HIV therapeutics may be targeted.
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21
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HIV-1 Mutant Assembly, Processing and Infectivity Expresses Pol Independent of Gag. Viruses 2020; 12:v12010054. [PMID: 31906562 PMCID: PMC7019881 DOI: 10.3390/v12010054] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/30/2019] [Accepted: 12/30/2019] [Indexed: 12/02/2022] Open
Abstract
The pol retrovirus gene encodes required enzymes for virus replication and maturation. Unlike HIV-1 Pol (expressed as a Gag–Pol fusion protein), foamy virus (described as an ancient retrovirus) expresses Pol without forming Gag–Pol polyproteins. We placed a “self-cleaving” 2A peptide between HIV-1 Gag and Pol. This construct, designated G2AP, is capable of producing virions with the same density as a wild-type (wt) HIV-1 particle. The 2A peptide allows for Pol to be packaged into virions independently from Gag following co-translationally cleaved from Gag. We found that G2AP exhibited only one-third the virus infectivity of the wt, likely due, at least in part, to defects in Pol packaging. Attenuated protease (PR) activity, or a reduction in Pol expression due to the placement of 2A-mediated Pol in a normal Gag–Pol frameshift context, resulted in significant increases in virus yields and/or titers. This suggests that reduced G2AP virus yields were largely due to increased PR activity associated with overexpressed Pol. Our data suggest that HIV-1 adopts a gag/pol ribosomal frameshifting mechanism to support virus assembly via the efficient modulation of Gag–Pol/Gag expression, as well as to promote viral enzyme packaging. Our results help clarify the molecular basis of HIV-1 gene expression and assembly.
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22
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Zou X, Wu J, Gu J, Shen L, Mao L. Application of Aptamers in Virus Detection and Antiviral Therapy. Front Microbiol 2019; 10:1462. [PMID: 31333603 PMCID: PMC6618307 DOI: 10.3389/fmicb.2019.01462] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/11/2019] [Indexed: 12/19/2022] Open
Abstract
Viral infections can cause serious diseases for humans and animals. Accurate and early detection of viruses is often crucial for clinical diagnosis and therapy. Aptamers are mostly single-stranded nucleotide sequences that are artificially synthesized by an in vitro technology known as the Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Similar to antibodies, aptamers bind specifically to their targets. However, compared with antibody, aptamers are easy to synthesize and modify and can bind to a broad range of targets. Thus, aptamers are promising for detecting viruses and treating viral infections. In this review, we briefly introduce aptamer-based biosensors (aptasensors) and describe their applications in rapid detection of viruses and as antiviral agents in treating infections. We summarize available data about the use of aptamers to detect and inhibit viruses. Furthermore, for the first time, we list aptamers specific to different viruses that have been screened out but have not yet been used for detecting viruses or treating viral infections. Finally, we analyze barriers and developing perspectives in the application of aptamer-based virus detection and therapeutics.
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Affiliation(s)
- Xinran Zou
- Department of Laboratory Medicine, The Affiliated People's Hospital, Jiangsu University, Zhenjiang, China.,Jiangsu Key Laboratory of Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Jing Wu
- Department of Laboratory Medicine, The Affiliated People's Hospital, Jiangsu University, Zhenjiang, China.,Jiangsu Key Laboratory of Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Jiaqi Gu
- Department of Laboratory Medicine, The Affiliated People's Hospital, Jiangsu University, Zhenjiang, China.,Jiangsu Key Laboratory of Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Li Shen
- Zhenjiang Center for Disease Control and Prevention, Jiangsu, China
| | - Lingxiang Mao
- Department of Laboratory Medicine, The Affiliated People's Hospital, Jiangsu University, Zhenjiang, China
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23
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Comas-Garcia M. Packaging of Genomic RNA in Positive-Sense Single-Stranded RNA Viruses: A Complex Story. Viruses 2019; 11:v11030253. [PMID: 30871184 PMCID: PMC6466141 DOI: 10.3390/v11030253] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 02/06/2023] Open
Abstract
The packaging of genomic RNA in positive-sense single-stranded RNA viruses is a key part of the viral infectious cycle, yet this step is not fully understood. Unlike double-stranded DNA and RNA viruses, this process is coupled with nucleocapsid assembly. The specificity of RNA packaging depends on multiple factors: (i) one or more packaging signals, (ii) RNA replication, (iii) translation, (iv) viral factories, and (v) the physical properties of the RNA. The relative contribution of each of these factors to packaging specificity is different for every virus. In vitro and in vivo data show that there are different packaging mechanisms that control selective packaging of the genomic RNA during nucleocapsid assembly. The goals of this article are to explain some of the key experiments that support the contribution of these factors to packaging selectivity and to draw a general scenario that could help us move towards a better understanding of this step of the viral infectious cycle.
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Affiliation(s)
- Mauricio Comas-Garcia
- Research Center for Health Sciences and Biomedicine (CICSaB), Universidad Autónoma de San Luis Potosí (UASLP), Av. Sierra Leona 550 Lomas 2da Seccion, 72810 San Luis Potosi, Mexico.
- Department of Sciences, Universidad Autónoma de San Luis Potosí (UASLP), Av. Chapultepec 1570, Privadas del Pedregal, 78295 San Luis Potosi, Mexico.
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24
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Chen Y, Li X, Su L, Chen X, Zhang S, Xu X, Zhang Z, Chen Y, XuHan X, Lin Y, Lai Z. Genome-wide identification and characterization of long non-coding RNAs involved in the early somatic embryogenesis in Dimocarpus longan Lour. BMC Genomics 2018; 19:805. [PMID: 30400813 PMCID: PMC6219066 DOI: 10.1186/s12864-018-5158-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 10/11/2018] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Long non-coding RNAs (lncRNAs) are involved in variable cleavage, transcriptional interference, regulation of DNA methylation and protein modification. However, the regulation of lncRNAs in plant somatic embryos remains unclear. The longan (Dimocarpus longan) somatic embryogenesis (SE) system is a good system for research on longan embryo development. RESULTS In this study, 7643 lncRNAs obtained during early SE in D. longan were identified by high-throughput sequencing, among which 6005 lncRNAs were expressed. Of the expressed lncRNAs, 4790 were found in all samples and 160 were specifically expressed in embryogenic callus (EC), 154 in incomplete embryogenic compact structures (ICpECs), and 376 in globular embryos (GEs). We annotated the 6005 expressed lncRNAs, and 1404 lncRNAs belonged to 506 noncoding RNA (ncRNA) families and 4682 lncRNAs were predicted to target protein-coding genes. The target genes included 5051 cis-regulated target genes (5712 pairs) and 1605 trans-regulated target genes (3618 pairs). KEGG analysis revealed that most of the differentially expressed target genes (mRNAs) of the lncRNAs were enriched in the "plant-pathogen interaction" and "plant hormone signaling" pathways during early longan SE. Real-time quantitative PCR confirmed that 20 selected lncRNAs showed significant differences in expression and that five lncRNAs were related to auxin response factors. Compared with the FPKM expression trends, 16 lncRNA expression trends were the same in qPCR. In lncRNA-miRNA-mRNA relationship prediction, 40 lncRNAs were predicted to function as eTMs for 15 miRNAs and 7 lncRNAs were identified as potential miRNA precursors. In addition, we verified the lncRNA-miRNA-mRNA regulatory relationships by transient expression of miRNAs (miR172a, miR159a.1 and miR398a). CONCLUSION Analyses of lncRNAs during early longan SE showed that differentially expressed lncRNAs were involved in expression regulation at each SE stage, and may form a regulatory network with miRNAs and mRNAs. These findings provide new insights into lncRNAs and lay a foundation for future functional analysis of lncRNAs during early longan SE.
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Affiliation(s)
- Yan Chen
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Xue Li
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Liyao Su
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Xu Chen
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Shuting Zhang
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Xiaoping Xu
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Zihao Zhang
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Yukun Chen
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Xu XuHan
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
- Institut de la Recherche Interdisciplinaire de Toulouse, IRIT-ARI, 31300 Toulouse, France
| | - Yuling Lin
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Zhongxiong Lai
- Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
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25
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Dubois N, Khoo KK, Ghossein S, Seissler T, Wolff P, McKinstry WJ, Mak J, Paillart JC, Marquet R, Bernacchi S. The C-terminal p6 domain of the HIV-1 Pr55 Gag precursor is required for specific binding to the genomic RNA. RNA Biol 2018; 15:923-936. [PMID: 29954247 DOI: 10.1080/15476286.2018.1481696] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The Pr55Gag precursor specifically selects the HIV-1 genomic RNA (gRNA) from a large excess of cellular and partially or fully spliced viral RNAs and drives the virus assembly at the plasma membrane. During these processes, the NC domain of Pr55Gag interacts with the gRNA, while its C-terminal p6 domain binds cellular and viral factors and orchestrates viral particle release. Gag∆p6 is a truncated form of Pr55Gag lacking the p6 domain usually used as a default surrogate for wild type Pr55Gag for in vitro analysis. With recent advance in production of full-length recombinant Pr55Gag, here, we tested whether the p6 domain also contributes to the RNA binding specificity of Pr55Gag by systematically comparing binding of Pr55Gag and Gag∆p6 to a panel of viral and cellular RNAs. Unexpectedly, our fluorescence data reveal that the p6 domain is absolutely required for specific binding of Pr55Gag to the HIV-1 gRNA. Its deletion resulted not only in a decreased affinity for gRNA, but also in an increased affinity for spliced viral and cellular RNAs. In contrast Gag∆p6 displayed a similar affinity for all tested RNAs. Removal of the C-terminal His-tag from Pr55Gag and Gag∆p6 uniformly increased the Kd values of the RNA-protein complexes by ~ 2.5 fold but did not affect the binding specificities of these proteins. Altogether, our results demonstrate a novel role of the p6 domain in the specificity of Pr55Gag-RNA interactions, and strongly suggest that the p6 domain contributes to the discrimination of HIV-1 gRNA from cellular and spliced viral mRNAs, which is necessary for its selective encapsidation.
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Affiliation(s)
- Noé Dubois
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | - Keith K Khoo
- b School of Medicine , Deakin University , Geelong , Australia.,c CSIRO Manufacturing , Parkville , Australia
| | - Shannon Ghossein
- b School of Medicine , Deakin University , Geelong , Australia.,c CSIRO Manufacturing , Parkville , Australia
| | - Tanja Seissler
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | - Philippe Wolff
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France.,d Plateforme protéomique Strasbourg-Esplanade, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | | | - Johnson Mak
- b School of Medicine , Deakin University , Geelong , Australia.,e Institute for Glycomics, Griffith University , Southport , Australia
| | - Jean-Christophe Paillart
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | - Roland Marquet
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
| | - Serena Bernacchi
- a Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS , Université de Strasbourg , Strasbourg , France
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26
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Bieniasz P, Telesnitsky A. Multiple, Switchable Protein:RNA Interactions Regulate Human Immunodeficiency Virus Type 1 Assembly. Annu Rev Virol 2018; 5:165-183. [PMID: 30048218 DOI: 10.1146/annurev-virology-092917-043448] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) particle assembly requires several protein:RNA interactions that vary widely in their character, from specific recognition of highly conserved and structured viral RNA elements to less specific interactions with variable RNA sequences. Genetic, biochemical, biophysical, and structural studies have illuminated how virion morphogenesis is accompanied by dramatic changes in the interactions among the protein and RNA virion components. The 5' leader RNA element drives RNA recognition by Gag upon initiation of HIV-1 assembly and can assume variable conformations that influence translation, dimerization, and Gag recognition. As Gag multimerizes on the plasma membrane, forming immature particles, its RNA binding specificity transiently changes, enabling recognition of the A-rich composition of the viral genome. Initiation of assembly may also be regulated by occlusion of the membrane binding surface of Gag by tRNA. Finally, recent work has suggested that RNA interactions with viral enzymes may activate and ensure the accuracy of virion maturation.
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Affiliation(s)
- Paul Bieniasz
- Laboratory of Retrovirology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA;
| | - Alice Telesnitsky
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan 48109, USA;
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27
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Smyth RP, Smith MR, Jousset AC, Despons L, Laumond G, Decoville T, Cattenoz P, Moog C, Jossinet F, Mougel M, Paillart JC, von Kleist M, Marquet R. In cell mutational interference mapping experiment (in cell MIME) identifies the 5' polyadenylation signal as a dual regulator of HIV-1 genomic RNA production and packaging. Nucleic Acids Res 2018; 46:e57. [PMID: 29514260 PMCID: PMC5961354 DOI: 10.1093/nar/gky152] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/02/2018] [Accepted: 03/01/2018] [Indexed: 12/28/2022] Open
Abstract
Non-coding RNA regulatory elements are important for viral replication, making them promising targets for therapeutic intervention. However, regulatory RNA is challenging to detect and characterise using classical structure-function assays. Here, we present in cell Mutational Interference Mapping Experiment (in cell MIME) as a way to define RNA regulatory landscapes at single nucleotide resolution under native conditions. In cell MIME is based on (i) random mutation of an RNA target, (ii) expression of mutated RNA in cells, (iii) physical separation of RNA into functional and non-functional populations, and (iv) high-throughput sequencing to identify mutations affecting function. We used in cell MIME to define RNA elements within the 5' region of the HIV-1 genomic RNA (gRNA) that are important for viral replication in cells. We identified three distinct RNA motifs controlling intracellular gRNA production, and two distinct motifs required for gRNA packaging into virions. Our analysis reveals the 73AAUAAA78 polyadenylation motif within the 5' PolyA domain as a dual regulator of gRNA production and gRNA packaging, and demonstrates that a functional polyadenylation signal is required for viral packaging even though it negatively affects gRNA production.
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Affiliation(s)
- Redmond P Smyth
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, IBMC, 15 rue René Descartes, 67000 Strasbourg, France
| | - Maureen R Smith
- Freie Universität Berlin, Department of Mathematics and Computer Science, Arnimallee 6, 14195 Berlin, Germany
| | - Anne-Caroline Jousset
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, IBMC, 15 rue René Descartes, 67000 Strasbourg, France
| | - Laurence Despons
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, IBMC, 15 rue René Descartes, 67000 Strasbourg, France
| | - Géraldine Laumond
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Thomas Decoville
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Pierre Cattenoz
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, IBMC, 15 rue René Descartes, 67000 Strasbourg, France
| | - Christiane Moog
- INSERM U1109, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Fabrice Jossinet
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, IBMC, 15 rue René Descartes, 67000 Strasbourg, France
| | - Marylène Mougel
- IRIM CNRS UMR9004, Université de Montpellier, Montpellier, France
| | - Jean-Christophe Paillart
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, IBMC, 15 rue René Descartes, 67000 Strasbourg, France
| | - Max von Kleist
- Freie Universität Berlin, Department of Mathematics and Computer Science, Arnimallee 6, 14195 Berlin, Germany
| | - Roland Marquet
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, IBMC, 15 rue René Descartes, 67000 Strasbourg, France
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28
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Ren W, Ji D, Xu X. Metal cofactor modulated folding and target recognition of HIV-1 NCp7. PLoS One 2018; 13:e0196662. [PMID: 29715277 PMCID: PMC5929515 DOI: 10.1371/journal.pone.0196662] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 04/17/2018] [Indexed: 01/01/2023] Open
Abstract
The HIV-1 nucleocapsid 7 (NCp7) plays crucial roles in multiple stages of HIV-1 life cycle, and its biological functions rely on the binding of zinc ions. Understanding the molecular mechanism of how the zinc ions modulate the conformational dynamics and functions of the NCp7 is essential for the drug development and HIV-1 treatment. In this work, using a structure-based coarse-grained model, we studied the effects of zinc cofactors on the folding and target RNA(SL3) recognition of the NCp7 by molecular dynamics simulations. After reproducing some key properties of the zinc binding and folding of the NCp7 observed in previous experiments, our simulations revealed several interesting features in the metal ion modulated folding and target recognition. Firstly, we showed that the zinc binding makes the folding transition states of the two zinc fingers less structured, which is in line with the Hammond effect observed typically in mutation, temperature or denaturant induced perturbations to protein structure and stability. Secondly, We showed that there exists mutual interplay between the zinc ion binding and NCp7-target recognition. Binding of zinc ions enhances the affinity between the NCp7 and the target RNA, whereas the formation of the NCp7-RNA complex reshapes the intrinsic energy landscape of the NCp7 and increases the stability and zinc affinity of the two zinc fingers. Thirdly, by characterizing the effects of salt concentrations on the target RNA recognition, we showed that the NCp7 achieves optimal balance between the affinity and binding kinetics near the physiologically relevant salt concentrations. In addition, the effects of zinc binding on the inter-domain conformational flexibility and folding cooperativity of the NCp7 were also discussed.
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Affiliation(s)
- Weitong Ren
- School of Physics, Nanjing University, Nanjing 210093, China
| | - Dongqing Ji
- School of Physics, Nanjing University, Nanjing 210093, China
| | - Xiulian Xu
- School of Physical Science and Technology, Yangzhou University, Yangzhou 225002, China
- * E-mail:
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29
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Dubois N, Marquet R, Paillart JC, Bernacchi S. Retroviral RNA Dimerization: From Structure to Functions. Front Microbiol 2018; 9:527. [PMID: 29623074 PMCID: PMC5874298 DOI: 10.3389/fmicb.2018.00527] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/08/2018] [Indexed: 01/18/2023] Open
Abstract
The genome of the retroviruses is a dimer composed by two homologous copies of genomic RNA (gRNA) molecules of positive polarity. The dimerization process allows two gRNA molecules to be non-covalently linked together through intermolecular base-pairing. This step is critical for the viral life cycle and is highly conserved among retroviruses with the exception of spumaretroviruses. Furthermore, packaging of two gRNA copies into viral particles presents an important evolutionary advantage for immune system evasion and drug resistance. Recent studies reported RNA switches models regulating not only gRNA dimerization, but also translation and packaging, and a spatio-temporal characterization of viral gRNA dimerization within cells are now at hand. This review summarizes our current understanding on the structural features of the dimerization signals for a variety of retroviruses (HIVs, MLV, RSV, BLV, MMTV, MPMV…), the mechanisms of RNA dimer formation and functional implications in the retroviral cycle.
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Affiliation(s)
- Noé Dubois
- Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS, Université de Strasbourg, Strasbourg, France
| | - Roland Marquet
- Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS, Université de Strasbourg, Strasbourg, France
| | - Jean-Christophe Paillart
- Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS, Université de Strasbourg, Strasbourg, France
| | - Serena Bernacchi
- Architecture et Réactivité de l'ARN, UPR 9002, IBMC, CNRS, Université de Strasbourg, Strasbourg, France
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30
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Ingemarsdotter CK, Zeng J, Long Z, Lever AML, Kenyon JC. An RNA-binding compound that stabilizes the HIV-1 gRNA packaging signal structure and specifically blocks HIV-1 RNA encapsidation. Retrovirology 2018. [PMID: 29540207 PMCID: PMC5853050 DOI: 10.1186/s12977-018-0407-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background NSC260594, a quinolinium derivative from the NCI diversity set II compound library, was previously identified in a target-based assay as an inhibitor of the interaction between the HIV-1 (ψ) stem-loop 3 (SL3) RNA and Gag. This compound was shown to exhibit potent antiviral activity. Here, the effects of this compound on individual stages of the viral lifecycle were examined by qRT-PCR, ELISA and Western blot, to see if its actions were specific to the viral packaging stage. The structural effects of NSC260594 binding to the HIV-1 gRNA were also examined by SHAPE and dimerization assays. Results Treatment of cells with NSC260594 did not reduce the number of integration events of incoming virus, and treatment of virus producing cells did not affect the level of intracellular Gag protein or viral particle release as determined by immunoblot. However, NSC260594 reduced the incorporation of gRNA into virions by up to 82%, without affecting levels of gRNA inside the cell. This reduction in packaging correlated closely with the reduction in infectivity of the released viral particles. To establish the structural effects of NSC260594 on the HIV-1 gRNA, we performed SHAPE analyses to pinpoint RNA structural changes. NSC260594 had a stabilizing effect on the wild type RNA that was not confined to SL3, but that was propagated across the structure. A packaging mutant lacking SL3 did not show this effect. Conclusions NSC260594 acts as a specific inhibitor of HIV-1 RNA packaging. No other viral functions are affected. Its action involves preventing the interaction of Gag with SL3 by stabilizing this small RNA stem-loop which then leads to stabilization of the global packaging signal region (psi or ψ). This confirms data, previously only shown in analyses of isolated SL3 oligonucleotides, that SL3 is structurally labile in the presence of Gag and that this is critical for the complete psi region to be able to adopt different conformations. Since replication is otherwise unaffected by NSC260594 the flexibility of SL3 appears to be a unique requirement for genome encapsidation and identifies this process as a highly specific drug target. This study is proof of principle that development of a new class of antiretroviral drugs that specifically target viral packaging by binding to the viral genomic RNA is achievable. Electronic supplementary material The online version of this article (10.1186/s12977-018-0407-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Carin K Ingemarsdotter
- Department of Medicine, University of Cambridge, Addenbrookes Hospital, Box 157, Level 5, Hills Rd, Cambridge, CB2 0QQ, UK
| | - Jingwei Zeng
- Department of Medicine, University of Cambridge, Addenbrookes Hospital, Box 157, Level 5, Hills Rd, Cambridge, CB2 0QQ, UK
| | - Ziqi Long
- Department of Medicine, University of Cambridge, Addenbrookes Hospital, Box 157, Level 5, Hills Rd, Cambridge, CB2 0QQ, UK
| | - Andrew M L Lever
- Department of Medicine, University of Cambridge, Addenbrookes Hospital, Box 157, Level 5, Hills Rd, Cambridge, CB2 0QQ, UK.,Department of Medicine, National University of Singapore, Singapore, Singapore
| | - Julia C Kenyon
- Department of Medicine, University of Cambridge, Addenbrookes Hospital, Box 157, Level 5, Hills Rd, Cambridge, CB2 0QQ, UK. .,Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore. .,Homerton College, University of Cambridge, Cambridge, UK.
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31
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Shi G, Suzuki T. Molecular Basis of Encapsidation of Hepatitis C Virus Genome. Front Microbiol 2018; 9:396. [PMID: 29563905 PMCID: PMC5845887 DOI: 10.3389/fmicb.2018.00396] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 02/21/2018] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C virus (HCV), a major etiologic agent of human liver diseases, is a positive-sense single-stranded RNA virus and is classified in the Flaviviridae family. Although research findings for the assembly of HCV particles are accumulating due to development of HCV cell culture system, the mechanism(s) by which the HCV genome becomes encapsidated remains largely unclear. In general, viral RNA represents only a small fraction of the RNA molecules in the cells infected with RNA viruses, but the viral genomic RNA is considered to selectively packaged into virions. It was recently demonstrated that HCV RNAs containing 3' end of the genome are selectively incorporated into virus particles during the assembly process and the 3' untranslated region functions as a cis-acting element for RNA packaging. Here, we discuss the molecular basis of RNA encapsidation of HCV and classical flaviviruses, contrast with the packaging mechanism of HIV-1.
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Affiliation(s)
- Guoli Shi
- Antiviral Immunity and Resistance Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD, United States
| | - Tetsuro Suzuki
- Department of Virology and Parasitology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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32
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Olgun HB, Tasyurek HM, Sanlioglu AD, Sanlioglu S. High-Titer Production of HIV-Based Lentiviral Vectors in Roller Bottles for Gene and Cell Therapy. Methods Mol Biol 2018; 1879:323-345. [PMID: 29797007 DOI: 10.1007/7651_2018_150] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Lentiviral vectors are becoming preferred vectors of choice for clinical gene therapy trials due to their safety, efficacy, and the long-term gene expression they provide. Although the efficacy of lentiviral vectors is mainly predetermined by the therapeutic genes they carry, they must be produced at high titers to exert therapeutic benefit for in vivo applications. Thus, there is need for practical, robust, and scalable viral vector production methods applicable to any laboratory setting. Here, we describe a practical lentiviral production technique in roller bottles yielding high-titer third-generation lentiviral vectors useful for in vivo gene transfer applications. CaPO4-mediated transient transfection protocol involving the use of a transfer vector and three different packaging plasmids is employed to generate lentivectors in roller bottles. Following clearance of cellular debris via low-speed centrifugation and filtration, virus is concentrated by high-speed ultracentrifugation over sucrose cushion.
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Affiliation(s)
- Hazal Banu Olgun
- Human Gene and Cell Therapy Center of Akdeniz University Hospitals, Antalya, Turkey
| | - Hale M Tasyurek
- Human Gene and Cell Therapy Center of Akdeniz University Hospitals, Antalya, Turkey
| | | | - Salih Sanlioglu
- Human Gene and Cell Therapy Center of Akdeniz University Hospitals, Antalya, Turkey.
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33
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Yaseen MM, Abuharfeil NM, Alqudah MA, Yaseen MM. Mechanisms and Factors That Drive Extensive Human Immunodeficiency Virus Type-1 Hypervariability: An Overview. Viral Immunol 2017; 30:708-726. [PMID: 29064351 DOI: 10.1089/vim.2017.0065] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The extensive hypervariability of human immunodeficiency virus type-1 (HIV-1) populations represents a major barrier against the success of currently available antiretroviral therapy. Moreover, it is still the most important obstacle that faces the development of an effective preventive vaccine against this infectious virus. Indeed, several factors can drive such hypervariability within and between HIV-1 patients. These factors include: first, the very low fidelity nature of HIV-1 reverse transcriptase; second, the extremely high HIV-1 replication rate; and third, the high genomic recombination rate that the virus has. All these factors together with the APOBEC3 proteins family and the immune and antiviral drugs pressures drive the extensive hypervariability of HIV-1 populations. Studying these factors and the mechanisms that drive such hypervariability will provide valuable insights that may guide the development of effective therapeutic and preventive strategies against HIV-1 infection in the near future. To this end, in this review, we summarized recent advances in this area of HIV-1 research.
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Affiliation(s)
- Mahmoud Mohammad Yaseen
- 1 Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Jordan University of Science and Technology , Irbid, Jordan
| | - Nizar Mohammad Abuharfeil
- 2 Department of Applied Biological Sciences, College of Science and Arts, Jordan University of Science and Technology , Irbid, Jordan
| | - Mohammad Ali Alqudah
- 3 Department of Clinical Pharmacy, College of Pharmacy, Jordan University of Science and Technology , Irbid, Jordan
| | - Mohammad Mahmoud Yaseen
- 4 Department of Public Health, College of Medicine, Jordan University of Science and Technology , Irbid, Jordan
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Comas-Garcia M, Datta SA, Baker L, Varma R, Gudla PR, Rein A. Dissection of specific binding of HIV-1 Gag to the 'packaging signal' in viral RNA. eLife 2017; 6. [PMID: 28726630 PMCID: PMC5531834 DOI: 10.7554/elife.27055] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 07/13/2017] [Indexed: 01/26/2023] Open
Abstract
Selective packaging of HIV-1 genomic RNA (gRNA) requires the presence of a cis-acting RNA element called the 'packaging signal' (Ψ). However, the mechanism by which Ψ promotes selective packaging of the gRNA is not well understood. We used fluorescence correlation spectroscopy and quenching data to monitor the binding of recombinant HIV-1 Gag protein to Cy5-tagged 190-base RNAs. At physiological ionic strength, Gag binds with very similar, nanomolar affinities to both Ψ-containing and control RNAs. We challenged these interactions by adding excess competing tRNA; introducing mutations in Gag; or raising the ionic strength. These modifications all revealed high specificity for Ψ. This specificity is evidently obscured in physiological salt by non-specific, predominantly electrostatic interactions. This nonspecific activity was attenuated by mutations in the MA, CA, and NC domains, including CA mutations disrupting Gag-Gag interaction. We propose that gRNA is selectively packaged because binding to Ψ nucleates virion assembly with particular efficiency.
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Affiliation(s)
- Mauricio Comas-Garcia
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, United States
| | - Siddhartha Ak Datta
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, United States
| | - Laura Baker
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, United States
| | | | - Prabhakar R Gudla
- Optical Microscopy and Analysis Laboratory, Cancer Research Technology Program, Leidos Biomedical Research, Inc., Frederick, United States
| | - Alan Rein
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, United States
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Liu Y, Nikolaitchik OA, Rahman SA, Chen J, Pathak VK, Hu WS. HIV-1 Sequence Necessary and Sufficient to Package Non-viral RNAs into HIV-1 Particles. J Mol Biol 2017; 429:2542-2555. [PMID: 28673553 DOI: 10.1016/j.jmb.2017.06.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 06/26/2017] [Accepted: 06/26/2017] [Indexed: 01/23/2023]
Abstract
Genome packaging is an essential step to generate infectious HIV-1 virions and is mediated by interactions between the viral protein Gag and cis-acting elements in the full-length RNA. The sequence necessary and sufficient to allow RNA genome packaging into an HIV-1 particle has not been defined. Here, we used two distinct reporter systems to determine the HIV-1 sequence required for heterologous, non-viral RNAs to be packaged into viral particles. Although the 5' untranslated region (UTR) of the HIV-1 RNA is known to be important for RNA packaging, we found that its ability to mediate packaging relies heavily on the context of the downstream sequences. Insertion of the 5' UTR and the first 32-nt of gag into two different reporter RNAs is not sufficient to mediate the packaging of these RNA into HIV-1 particles. However, adding the 5' half of the gag gene to the 5' UTR strongly facilitates the packaging of two reporter RNAs; such RNAs can be packaged at >50% of the efficiencies of an HIV-1 near full-length vector. To further examine the role of the gag sequence in RNA packaging, we replaced the 5' gag sequence in the HIV-1 genome with two codon-optimized gag sequences and found that such substitutions only resulted in a moderate decrease of RNA packaging efficiencies. Taken together, these results indicated that both HIV-1 5' UTR and the 5' gag sequence are required for efficient packaging of non-viral RNA into HIV-1 particles, although the gag sequence likely plays an indirect role in genome packaging.
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Affiliation(s)
- Yang Liu
- Viral Recombination Section, HIV Dynamics and Replication Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Olga A Nikolaitchik
- Viral Recombination Section, HIV Dynamics and Replication Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Sheikh Abdul Rahman
- Viral Recombination Section, HIV Dynamics and Replication Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Jianbo Chen
- Viral Recombination Section, HIV Dynamics and Replication Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Vinay K Pathak
- Viral Mutation Section, HIV Dynamics and Replication Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Wei-Shau Hu
- Viral Recombination Section, HIV Dynamics and Replication Program, National Cancer Institute, Frederick, MD 21702, USA.
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Vink CA, Counsell JR, Perocheau DP, Karda R, Buckley SMK, Brugman MH, Galla M, Schambach A, McKay TR, Waddington SN, Howe SJ. Eliminating HIV-1 Packaging Sequences from Lentiviral Vector Proviruses Enhances Safety and Expedites Gene Transfer for Gene Therapy. Mol Ther 2017; 25:1790-1804. [PMID: 28550974 PMCID: PMC5542766 DOI: 10.1016/j.ymthe.2017.04.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 12/30/2022] Open
Abstract
Lentiviral vector genomic RNA requires sequences that partially overlap wild-type HIV-1 gag and env genes for packaging into vector particles. These HIV-1 packaging sequences constitute 19.6% of the wild-type HIV-1 genome and contain functional cis elements that potentially compromise clinical safety. Here, we describe the development of a novel lentiviral vector (LTR1) with a unique genomic structure designed to prevent transfer of HIV-1 packaging sequences to patient cells, thus reducing the total HIV-1 content to just 4.8% of the wild-type genome. This has been achieved by reconfiguring the vector to mediate reverse-transcription with a single strand transfer, instead of the usual two, and in which HIV-1 packaging sequences are not copied. We show that LTR1 vectors offer improved safety in their resistance to remobilization in HIV-1 particles and reduced frequency of splicing into human genes. Following intravenous luciferase vector administration to neonatal mice, LTR1 sustained a higher level of liver transgene expression than an equivalent dose of a standard lentivirus. LTR1 vectors produce reverse-transcription products earlier and start to express transgenes significantly quicker than standard lentiviruses after transduction. Finally, we show that LTR1 is an effective lentiviral gene therapy vector as demonstrated by correction of a mouse hemophilia B model.
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Affiliation(s)
- Conrad A Vink
- Molecular and Cellular Immunology, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - John R Counsell
- Molecular and Cellular Immunology, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK; Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK.
| | - Dany P Perocheau
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
| | - Rajvinder Karda
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
| | - Suzanne M K Buckley
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
| | - Martijn H Brugman
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, 2300 RC Leiden, the Netherlands
| | - Melanie Galla
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Axel Schambach
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Tristan R McKay
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester M15 6BH, UK
| | - Simon N Waddington
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK; MRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg 2000, South Africa
| | - Steven J Howe
- Molecular and Cellular Immunology, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK; Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
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Pollack RA, Jones RB, Pertea M, Bruner KM, Martin AR, Thomas AS, Capoferri AA, Beg SA, Huang SH, Karandish S, Hao H, Halper-Stromberg E, Yong PC, Kovacs C, Benko E, Siliciano RF, Ho YC. Defective HIV-1 Proviruses Are Expressed and Can Be Recognized by Cytotoxic T Lymphocytes, which Shape the Proviral Landscape. Cell Host Microbe 2017; 21:494-506.e4. [PMID: 28407485 DOI: 10.1016/j.chom.2017.03.008] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 02/07/2017] [Accepted: 03/16/2017] [Indexed: 12/31/2022]
Abstract
Despite antiretroviral therapy, HIV-1 persists in memory CD4+ T cells, creating a barrier to cure. The majority of HIV-1 proviruses are defective and considered clinically irrelevant. Using cells from HIV-1-infected individuals and reconstructed patient-derived defective proviruses, we show that defective proviruses can be transcribed into RNAs that are spliced and translated. Proviruses with defective major splice donors (MSDs) can activate novel splice sites to produce HIV-1 transcripts, and cells with these proviruses can be recognized by HIV-1-specific cytotoxic T lymphocytes (CTLs). Further, cells with proviruses containing lethal mutations upstream of CTL epitopes can also be recognized by CTLs, potentially through aberrant translation. Thus, CTLs may change the landscape of HIV-1 proviruses by preferentially targeting cells with specific types of defective proviruses. Additionally, the expression of defective proviruses will need to be considered in the measurement of HIV-1 latency reversal.
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Affiliation(s)
- Ross A Pollack
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - R Brad Jones
- Department of Microbiology, Immunology, and Tropical Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Mihaela Pertea
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Katherine M Bruner
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alyssa R Martin
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Allison S Thomas
- Department of Microbiology, Immunology, and Tropical Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Adam A Capoferri
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA
| | - Subul A Beg
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA
| | - Szu-Han Huang
- Department of Microbiology, Immunology, and Tropical Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Sara Karandish
- Department of Microbiology, Immunology, and Tropical Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Haiping Hao
- Deep Sequencing & Microarray Core, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Patrick C Yong
- Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Colin Kovacs
- Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada; Maple Leaf Medical Clinic, Toronto, ON M5G 1K2, Canada
| | - Erika Benko
- Maple Leaf Medical Clinic, Toronto, ON M5G 1K2, Canada
| | - Robert F Siliciano
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA
| | - Ya-Chi Ho
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Subcellular Localization of HIV-1 gag-pol mRNAs Regulates Sites of Virion Assembly. J Virol 2017; 91:JVI.02315-16. [PMID: 28053097 DOI: 10.1128/jvi.02315-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 12/23/2016] [Indexed: 02/07/2023] Open
Abstract
Full-length unspliced human immunodeficiency virus type 1 (HIV-1) RNAs serve dual roles in the cytoplasm as mRNAs encoding the Gag and Gag-Pol capsid proteins as well as genomic RNAs (gRNAs) packaged by Gag into virions undergoing assembly at the plasma membrane (PM). Because Gag is sufficient to drive the assembly of virus-like particles even in the absence of gRNA binding, whether viral RNA trafficking plays an active role in the native assembly pathway is unknown. In this study, we tested the effects of modulating the cytoplasmic abundance or distribution of full-length viral RNAs on Gag trafficking and assembly in the context of single cells. Increasing full-length viral RNA abundance or distribution had little-to-no net effect on Gag assembly competency when provided in trans In contrast, artificially tethering full-length viral RNAs or surrogate gag-pol mRNAs competent for Gag synthesis to non-PM membranes or the actin cytoskeleton severely reduced net virus particle production. These effects were explained, in large part, by RNA-directed changes to Gag's distribution in the cytoplasm, yielding aberrant subcellular sites of virion assembly. Interestingly, RNA-dependent disruption of Gag trafficking required either of two cis-acting RNA regulatory elements: the 5' packaging signal (Psi) bound by Gag during genome encapsidation or, unexpectedly, the Rev response element (RRE), which regulates the nuclear export of gRNAs and other intron-retaining viral RNAs. Taken together, these data support a model for native infection wherein structural features of the gag-pol mRNA actively compartmentalize Gag to preferred sites within the cytoplasm and/or PM.IMPORTANCE The spatial distribution of viral mRNAs within the cytoplasm can be a crucial determinant of efficient translation and successful virion production. Here we provide direct evidence that mRNA subcellular trafficking plays an important role in regulating the assembly of human immunodeficiency virus type 1 (HIV-1) virus particles at the plasma membrane (PM). Artificially tethering viral mRNAs encoding Gag capsid proteins (gag-pol mRNAs) to distinct non-PM subcellular locales, such as cytoplasmic vesicles or the actin cytoskeleton, markedly alters Gag subcellular distribution, relocates sites of assembly, and reduces net virus particle production. These observations support a model for native HIV-1 assembly wherein HIV-1 gag-pol mRNA localization helps to confine interactions between Gag, viral RNAs, and host determinants in order to ensure virion production at the right place and right time. Direct perturbation of HIV-1 mRNA subcellular localization may represent a novel antiviral strategy.
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Parboosing R, Chonco L, de la Mata FJ, Govender T, Maguire GE, Kruger HG. Potential inhibition of HIV-1 encapsidation by oligoribonucleotide-dendrimer nanoparticle complexes. Int J Nanomedicine 2017; 12:317-325. [PMID: 28115849 PMCID: PMC5221794 DOI: 10.2147/ijn.s114446] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Background Encapsidation, the process during which the genomic RNA of HIV is packaged into viral particles, is an attractive target for antiviral therapy. This study explores a novel nanotechnology-based strategy to inhibit HIV encapsidation by an RNA decoy mechanism. The design of the 16-mer oligoribonucleotide (RNA) decoy is based on the sequence of stem loop 3 (SL3) of the HIV packaging signal (Ψ). Recognition of the packaging signal is essential to the encapsidation process. It is theorized that the decoy RNA, by mimicking the packaging signal, will disrupt HIV packaging if efficiently delivered into lymphocytes by complexation with a carbosilane dendrimer. The aim of the study is to measure the uptake, toxicity, and antiviral activity of the dendrimer–RNA nanocomplex. Materials and methods A dendriplex was formed between cationic carbosilane dendrimers and the RNA decoy. Uptake of the fluorescein-labeled RNA into MT4 lymphocytes was determined by flow cytometry and confocal microscopy. The cytoprotective effect (50% effective concentration [EC50]) and the effect on HIV replication were determined in vitro by the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and viral load measurements, respectively. Results Flow cytometry and confocal imaging demonstrated efficient transfection of lymphocytes. The dendriplex containing the Ψ decoy showed some activity (EC50 =3.20 µM, selectivity index =8.4). However, there was no significant suppression of HIV viral load. Conclusion Oligoribonucleotide decoys containing SL3 of the packaging sequence are efficiently delivered into lymphocytes by carbosilane dendrimers where they exhibit a modest cytoprotective effect against HIV infection.
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Affiliation(s)
- Raveen Parboosing
- Department of Virology, University of KwaZulu-Natal; National Health Laboratory Service, Durban, South Africa
| | - Louis Chonco
- Department of Virology, University of KwaZulu-Natal; National Health Laboratory Service, Durban, South Africa
| | - Francisco Javier de la Mata
- Organic and Inorganic Chemistry Department, University of Alcalá, Alcalá de Henares; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban, South Africa
| | - Glenn Em Maguire
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, University of KwaZulu-Natal, Durban, South Africa
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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.
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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
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Kutluay SB, Bieniasz PD. Analysis of HIV-1 Gag-RNA Interactions in Cells and Virions by CLIP-seq. Methods Mol Biol 2016; 1354:119-31. [PMID: 26714708 DOI: 10.1007/978-1-4939-3046-3_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Next-generation sequencing-based methodologies have revolutionized the analysis of protein-nucleic acid complexes; yet these novel approaches have rarely been applied in virology. Because it has an RNA genome, RNA-protein interactions play critical roles in human immunodeficiency virus type 1 (HIV-1) replication. In many cases, the binding sites of proteins on HIV-1 RNA molecules in physiologically relevant settings are not known. Cross-linking-immunoprecipitation sequencing (CLIP-seq) methodologies, which combine immunoprecipitation of covalently crosslinked protein-RNA complexes with high-throughput sequencing, is a powerful technique that can be applied to such questions as it provides a global account of RNA sequences bound by a RNA-binding protein of interest in physiological settings at near-nucleotide resolution. Here, we describe the application of the CLIP-seq methodology to identify the RNA molecules that are bound by the HIV-1 Gag protein in cells and in virions. This protocol can easily be applied to other viral and cellular RNA-binding proteins that influence HIV-1 replication.
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Affiliation(s)
- Sebla B Kutluay
- Laboratory of Retrovirology, Aaron Diamond AIDS Research Center, The Rockefeller University, 455 First Avenue, New York, NY, 10016, USA. .,Department of Molecular Microbiology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO, 63110, USA.
| | - Paul D Bieniasz
- Laboratory of Retrovirology, Aaron Diamond AIDS Research Center, The Rockefeller University, 455 First Avenue, New York, NY, 10016, USA. .,Howard Hughes Medical Institute, Aaron Diamond AIDS Research Center, The Rockefeller University, 455 First Avenue, New York, NY, 10016, USA.
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Cross- and Co-Packaging of Retroviral RNAs and Their Consequences. Viruses 2016; 8:v8100276. [PMID: 27727192 PMCID: PMC5086612 DOI: 10.3390/v8100276] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/03/2016] [Accepted: 10/03/2016] [Indexed: 12/23/2022] Open
Abstract
Retroviruses belong to the family Retroviridae and are ribonucleoprotein (RNP) particles that contain a dimeric RNA genome. Retroviral particle assembly is a complex process, and how the virus is able to recognize and specifically capture the genomic RNA (gRNA) among millions of other cellular and spliced retroviral RNAs has been the subject of extensive investigation over the last two decades. The specificity towards RNA packaging requires higher order interactions of the retroviral gRNA with the structural Gag proteins. Moreover, several retroviruses have been shown to have the ability to cross-/co-package gRNA from other retroviruses, despite little sequence homology. This review will compare the determinants of gRNA encapsidation among different retroviruses, followed by an examination of our current understanding of the interaction between diverse viral genomes and heterologous proteins, leading to their cross-/co-packaging. Retroviruses are well-known serious animal and human pathogens, and such a cross-/co-packaging phenomenon could result in the generation of novel viral variants with unknown pathogenic potential. At the same time, however, an enhanced understanding of the molecular mechanisms involved in these specific interactions makes retroviruses an attractive target for anti-viral drugs, vaccines, and vectors for human gene therapy.
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Gautam P, Recino A, Foale RD, Zhao J, Gan SU, Wallberg M, Calne R, Lever AML. Promoter optimisation of lentiviral vectors for efficient insulin gene expression in canine mesenchymal stromal cells: potential surrogate beta cells. J Gene Med 2016; 18:312-321. [PMID: 27572655 DOI: 10.1002/jgm.2900] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/02/2016] [Accepted: 08/25/2016] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND The lack of an ideal cell type that can be easily acquired, modified to produce insulin, and re-implanted has been a limitation for ex vivo insulin gene therapy. Canine diabetes is currently treated with human insulin and is a good model for human diabetes. Mesenchymal stromal cells (MSCs) are a promising candidate cell type for gene therapy. In the present study, we optimised insulin production using lentiviral transduced canine MSCs (cMSCs), aiming to evaluate their ability for use as surrogate beta cells. METHODS Canine MSCs were derived from bone marrow and validated by measuring the expression of MSC lineage specific markers. Lentivirus vectors encoding the proinsulin gene (with or without a Kozak sequence) under the control of spleen focus forming virus, cytomegalovirus, elongation factor 1α and simian virus 40 promotors were generated and used to transduce primary cMSCs and a hepatocyte cell line. The insulin-producing capacity of transduced primary cMSCs was assessed by measuring the concentration of C-peptide produced. RESULTS Primary cMSC could be readily expanded in culture and efficiently transduced using lentiviral vectors encoding proinsulin. Increasing the multiplicity of infection from 3 to 20 led to an increase in C-peptide secretion (from 1700 to 4000 pmol/l). The spleen focus forming virus promoter conferred the strongest transcriptional ability. CONCLUSIONS The results of the present study suggest that optimised lentiviral transduction of the insulin gene into primary cMSCs renders these cells capable of secreting insulin over both the short- and long-term, in sufficient quantities in vitro to support their potential use in insulin gene therapy.
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Affiliation(s)
- Pratigya Gautam
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Asha Recino
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Robert D Foale
- Dick White Referrals, Station Farm, Six Mile Bottom, Suffolk, UK
| | - Jing Zhao
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Shu Uin Gan
- Department of Surgery, National Institute of Singapore, Singapore
| | - Maja Wallberg
- Dick White Referrals, Station Farm, Six Mile Bottom, Suffolk, UK
| | - Roy Calne
- Department of Surgery, University of Cambridge, Cambridge, UK
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Comas-Garcia M, Davis SR, Rein A. On the Selective Packaging of Genomic RNA by HIV-1. Viruses 2016; 8:v8090246. [PMID: 27626441 PMCID: PMC5035960 DOI: 10.3390/v8090246] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/16/2016] [Accepted: 08/30/2016] [Indexed: 12/12/2022] Open
Abstract
Like other retroviruses, human immunodeficiency virus type 1 (HIV-1) selectively packages genomic RNA (gRNA) during virus assembly. However, in the absence of the gRNA, cellular messenger RNAs (mRNAs) are packaged. While the gRNA is selected because of its cis-acting packaging signal, the mechanism of this selection is not understood. The affinity of Gag (the viral structural protein) for cellular RNAs at physiological ionic strength is not much higher than that for the gRNA. However, binding to the gRNA is more salt-resistant, implying that it has a higher non-electrostatic component. We have previously studied the spacer 1 (SP1) region of Gag and showed that it can undergo a concentration-dependent conformational transition. We proposed that this transition represents the first step in assembly, i.e., the conversion of Gag to an assembly-ready state. To explain selective packaging of gRNA, we suggest here that binding of Gag to gRNA, with its high non-electrostatic component, triggers this conversion more readily than binding to other RNAs; thus we predict that a Gag-gRNA complex will nucleate particle assembly more efficiently than other Gag-RNA complexes. New data shows that among cellular mRNAs, those with long 3'-untranslated regions (UTR) are selectively packaged. It seems plausible that the 3'-UTR, a stretch of RNA not occupied by ribosomes, offers a favorable binding site for Gag.
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Affiliation(s)
- Mauricio Comas-Garcia
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Sean R Davis
- Genetics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA.
| | - Alan Rein
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
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The Life-Cycle of the HIV-1 Gag-RNA Complex. Viruses 2016; 8:v8090248. [PMID: 27626439 PMCID: PMC5035962 DOI: 10.3390/v8090248] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/30/2016] [Accepted: 09/02/2016] [Indexed: 12/16/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) replication is a highly regulated process requiring the recruitment of viral and cellular components to the plasma membrane for assembly into infectious particles. This review highlights the recent process of understanding the selection of the genomic RNA (gRNA) by the viral Pr55Gag precursor polyprotein, and the processes leading to its incorporation into viral particles.
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Abstract
A significant part of eukaryotic genomes is formed by transposable elements (TEs) containing not only genes but also regulatory sequences. Some of the regulatory sequences located within TEs can form secondary structures like hairpins or three-stranded (triplex DNA) and four-stranded (quadruplex DNA) conformations. This review focuses on recent evidence showing that G-quadruplex-forming sequences in particular are often present in specific parts of TEs in plants and humans. We discuss the potential role of these structures in the TE life cycle as well as the impact of G-quadruplexes on replication, transcription, translation, chromatin status, and recombination. The aim of this review is to emphasize that TEs may serve as vehicles for the genomic spread of G-quadruplexes. These non-canonical DNA structures and their conformational switches may constitute another regulatory system that, together with small and long non-coding RNA molecules and proteins, contribute to the complex cellular network resulting in the large diversity of eukaryotes.
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47
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Hellmund C, Lever AML. Coordination of Genomic RNA Packaging with Viral Assembly in HIV-1. Viruses 2016; 8:E192. [PMID: 27428992 PMCID: PMC4974527 DOI: 10.3390/v8070192] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/04/2016] [Accepted: 07/07/2016] [Indexed: 12/15/2022] Open
Abstract
The tremendous progress made in unraveling the complexities of human immunodeficiency virus (HIV) replication has resulted in a library of drugs to target key aspects of the replication cycle of the virus. Yet, despite this accumulated wealth of knowledge, we still have much to learn about certain viral processes. One of these is virus assembly, where the viral genome and proteins come together to form infectious progeny. Here we review this topic from the perspective of how the route to production of an infectious virion is orchestrated by the viral genome, and we compare and contrast aspects of the assembly mechanisms employed by HIV-1 with those of other RNA viruses.
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Affiliation(s)
- Chris Hellmund
- Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK.
| | - Andrew M L Lever
- Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK.
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Carlson LA, Bai Y, Keane SC, Doudna JA, Hurley JH. Reconstitution of selective HIV-1 RNA packaging in vitro by membrane-bound Gag assemblies. eLife 2016; 5. [PMID: 27343348 PMCID: PMC4946900 DOI: 10.7554/elife.14663] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 06/24/2016] [Indexed: 12/23/2022] Open
Abstract
HIV-1 Gag selects and packages a dimeric, unspliced viral RNA in the context of a large excess of cytosolic human RNAs. As Gag assembles on the plasma membrane, the HIV-1 genome is enriched relative to cellular RNAs by an unknown mechanism. We used a minimal system consisting of purified RNAs, recombinant HIV-1 Gag and giant unilamellar vesicles to recapitulate the selective packaging of the 5’ untranslated region of the HIV-1 genome in the presence of excess competitor RNA. Mutations in the CA-CTD domain of Gag which subtly affect the self-assembly of Gag abrogated RNA selectivity. We further found that tRNA suppresses Gag membrane binding less when Gag has bound viral RNA. The ability of HIV-1 Gag to selectively package its RNA genome and its self-assembly on membranes are thus interdependent on one another. DOI:http://dx.doi.org/10.7554/eLife.14663.001 HIV-1 is the virus that causes AIDS – short for acquired immune deficiency syndrome – in humans. When HIV-1 infects a person, it targets cells of the immune system, which normally act to defend the body against infections. As the virus spreads from one immune cell to the next, it weakens the immune system so that individuals become more vulnerable to other illnesses. A cell infected with HIV-1 creates new virus particles at its surface and then releases the particles so that they can infect other cells. HIV-1 viruses encode their genetic information as molecules of ribonucleic acid (RNA). However, the host cell also makes many other RNA molecules that do not contain virus genes so there must be a mechanism in place to ensure that the new virus particles only contain viral RNA. An HIV-1 protein called Gag is responsible for assembling new virus particles and several Gag proteins come together on the cell membrane to form a honeycomb-like structure called the immature lattice. However, it is not clear how Gag is able to select the right RNA molecules. To study how RNA is packaged into new HIV-1 particles, Carlson et al. used artificial versions of the cell membrane, viral RNA and the virus protein Gag to create a simple cell-free system. This system shows that all that is needed for viral RNA to be correctly packaged into new HIV-1 particles is for Gag to be attached to the cell membrane in such a way that the lattice forms correctly. Disturbing the immature lattice by altering the Gag proteins can result in a drastic loss of RNA selectivity. Further experiments show that other molecules in host cells called transfer RNAs enhance the ability of Gag to select the RNAs that encode virus genes. Carlson et al.’s findings reveal a link between the formation of the Gag lattice and the packaging of virus genes into new virus particles. Drugs that inhibit this process could have the potential to be used as therapies against HIV-1. A future challenge will be to re-create the entire process of HIV-1 assembly in a cell-free system, which would make it easier to develop new drugs that target the process. DOI:http://dx.doi.org/10.7554/eLife.14663.002
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Affiliation(s)
- Lars-Anders Carlson
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States
| | - Yun Bai
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Sarah C Keane
- Howard Hughes Medical Institute, Baltimore, United States.,Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, United States
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States.,Howard Hughes Medical Institute, University of California, Berkeley, Baltimore, United States.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, United States
| | - James H Hurley
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, United States.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, United States
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Lippens JL, Mangrum J, McIntyre W, Redick B, Fabris D. A simple heated-capillary modification improves the analysis of non-covalent complexes by Z-spray electrospray ionization. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:773-83. [PMID: 26864529 PMCID: PMC4868961 DOI: 10.1002/rcm.7490] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 12/11/2015] [Accepted: 12/15/2015] [Indexed: 05/29/2023]
Abstract
RATIONALE The observation of intact non-covalent complexes by electrospray ionization mass spectrometry (ESI-MS) hinges on the ability to minimize in-source activation processes that take place during analyte desolvation. We explored the merits of replacing the sampling cone of a standard Z-spray source with a heated capillary that makes the desolvation process slower and more gradual. We employed well-characterized protein-RNA, RNA-RNA, and DNA-DNA assemblies to compare the alternative configurations. METHODS Mass analysis evaluated the integrity of the complexes, whereas traveling wave ion mobility experiments assessed the stability of biomolecular structure. Analyses were performed back-to-back on the same samples on a Synapt G2 HDMS equipped with either the standard sampling cone or the heated-capillary apparatus. In each configuration, the source/capillary temperature was varied in controlled fashion, while keeping all other desolvation parameters constant to monitor the in-source dissociation of selected DNA duplexes. Ion mobility data were obtained from the same precursor by using the alternative configurations under the same settings. RESULTS Monitoring the percentage of associated complex demonstrated that the heated capillary provided softer desolvation that was more conducive to the detection of intact non-covalent interactions. This configuration failed to produce complete dissociation of 14 bp and 24 bp duplexes, even when the source/capillary temperature was increased well above their solution melting points. Analyzed by IMS-MS, a selected construct displayed just one conformation with the heated capillary, but two with the standard sampling cone. CONCLUSIONS The heated capillary minimizes in-source activation processes that can lead to unintended dissociation of complexes and perturbation of biomolecular structure, which rely on the integrity of non-covalent interactions. This effect can be attributed to the attenuation of the supersonic expansion typical of the Z-spray geometry and the greater ability to control the energy imparted to the system. This hardware modification will be expected to benefit the analysis of biomolecular structure performed on this particular instrumental platform.
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Affiliation(s)
| | | | | | - Bill Redick
- The RNA Institute, University at Albany (SUNY)
| | - D. Fabris
- The RNA Institute, University at Albany (SUNY)
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van Bel N, Ghabri A, Das AT, Berkhout B. The HIV-1 leader RNA is exquisitely sensitive to structural changes. Virology 2015; 483:236-52. [DOI: 10.1016/j.virol.2015.03.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 03/05/2015] [Accepted: 03/27/2015] [Indexed: 01/14/2023]
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