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Duchon A, Hu WS. HIV-1 RNA genome packaging: it's G-rated. mBio 2024; 15:e0086123. [PMID: 38411060 PMCID: PMC11005445 DOI: 10.1128/mbio.00861-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024] Open
Abstract
A member of the Retroviridae, human immunodeficiency virus type 1 (HIV-1), uses the RNA genome packaged into nascent virions to transfer genetic information to its progeny. The genome packaging step is a highly regulated and extremely efficient process as a vast majority of virus particles contain two copies of full-length unspliced HIV-1 RNA that form a dimer. Thus, during virus assembly HIV-1 can identify and selectively encapsidate HIV-1 unspliced RNA from an abundant pool of cellular RNAs and various spliced HIV-1 RNAs. Several "G" features facilitate the packaging of a dimeric RNA genome. The viral polyprotein Gag orchestrates virus assembly and mediates RNA genome packaging. During this process, Gag preferentially binds unpaired guanosines within the highly structured 5' untranslated region (UTR) of HIV-1 RNA. In addition, the HIV-1 unspliced RNA provides a scaffold that promotes Gag:Gag interactions and virus assembly, thereby ensuring its packaging. Intriguingly, recent studies have shown that the use of different guanosines at the junction of U3 and R as transcription start sites results in HIV-1 unspliced RNA species with 99.9% identical sequences but dramatically distinct 5' UTR conformations. Consequently, one species of unspliced RNA is preferentially packaged over other nearly identical RNAs. These studies reveal how conformations affect the functions of HIV-1 RNA elements and the complex regulation of HIV-1 replication. In this review, we summarize cis- and trans-acting elements critical for HIV-1 RNA packaging, locations of Gag:RNA interactions that mediate genome encapsidation, and the effects of transcription start sites on the structure and packaging of HIV-1 RNA.
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Affiliation(s)
- Alice Duchon
- Viral Recombination Section, HIV Dynamics and Replication Program, National Cancer Institute, Frederick, Maryland, USA
| | - Wei-Shau Hu
- Viral Recombination Section, HIV Dynamics and Replication Program, National Cancer Institute, Frederick, Maryland, USA
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2
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Guillin O, Albalat E, Vindry C, Errazuriz-Cerda E, Ohlmann T, Balter V, Chavatte L. Zinc Uptake by HIV-1 Viral Particles: An Isotopic Study. Int J Mol Sci 2023; 24:15274. [PMID: 37894953 PMCID: PMC10607083 DOI: 10.3390/ijms242015274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Zinc, an essential trace element that serves as a cofactor for numerous cellular and viral proteins, plays a central role in the dynamics of HIV-1 infection. Among the viral proteins, the nucleocapsid NCp7, which contains two zinc finger motifs, is abundantly present viral particles and plays a crucial role in coating HIV-1 genomic RNA, thus concentrating zinc within virions. In this study, we investigated whether HIV-1 virus production impacts cellular zinc homeostasis and whether isotopic fractionation occurs between the growth medium, the producing cells, and the viral particles. We found that HIV-1 captures a significant proportion of cellular zinc in the neo-produced particles. Furthermore, as cells grow, they accumulate lighter zinc isotopes from the medium, resulting in a concentration of heavier isotopes in the media, and the viruses exhibit a similar isotopic fractionation to the producing cells. Moreover, we generated HIV-1 particles in HEK293T cells enriched with each of the five zinc isotopes to assess the potential effects on the structure and infectivity of the viruses. As no strong difference was observed between the HIV-1 particles produced in the various conditions, we have demonstrated that enriched isotopes can be accurately used in future studies to trace the fate of zinc in cells infected by HIV-1 particles. Comprehending the mechanisms underlying zinc absorption by HIV-1 viral particles offers the potential to provide insights for developing future treatments aimed at addressing this specific facet of the virus's life cycle.
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Affiliation(s)
- Olivia Guillin
- Centre International de Recherche en Infectiologie (CIRI), 69007 Lyon, France; (O.G.); (C.V.); (T.O.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité U1111, 69007 Lyon, France
- Ecole Normale Supérieure de Lyon, 69007 Lyon, France;
- Division Recherche, Université Claude Bernard Lyon 1 (UCBL1), 69008 Lyon, France
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5308 (UMR5308), 69007 Lyon, France
| | - Emmanuelle Albalat
- Ecole Normale Supérieure de Lyon, 69007 Lyon, France;
- Division Recherche, Université Claude Bernard Lyon 1 (UCBL1), 69008 Lyon, France
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5276 (UMR5276), 69007 Lyon, France
| | - Caroline Vindry
- Centre International de Recherche en Infectiologie (CIRI), 69007 Lyon, France; (O.G.); (C.V.); (T.O.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité U1111, 69007 Lyon, France
- Ecole Normale Supérieure de Lyon, 69007 Lyon, France;
- Division Recherche, Université Claude Bernard Lyon 1 (UCBL1), 69008 Lyon, France
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5308 (UMR5308), 69007 Lyon, France
| | - Elisabeth Errazuriz-Cerda
- Center of Quantitative Imagery Lyon Est (CIQLE), Université Claude Bernard Lyon 1, 69008 Lyon, France;
| | - Théophile Ohlmann
- Centre International de Recherche en Infectiologie (CIRI), 69007 Lyon, France; (O.G.); (C.V.); (T.O.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité U1111, 69007 Lyon, France
- Ecole Normale Supérieure de Lyon, 69007 Lyon, France;
- Division Recherche, Université Claude Bernard Lyon 1 (UCBL1), 69008 Lyon, France
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5308 (UMR5308), 69007 Lyon, France
| | - Vincent Balter
- Ecole Normale Supérieure de Lyon, 69007 Lyon, France;
- Division Recherche, Université Claude Bernard Lyon 1 (UCBL1), 69008 Lyon, France
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5276 (UMR5276), 69007 Lyon, France
| | - Laurent Chavatte
- Centre International de Recherche en Infectiologie (CIRI), 69007 Lyon, France; (O.G.); (C.V.); (T.O.)
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité U1111, 69007 Lyon, France
- Ecole Normale Supérieure de Lyon, 69007 Lyon, France;
- Division Recherche, Université Claude Bernard Lyon 1 (UCBL1), 69008 Lyon, France
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5308 (UMR5308), 69007 Lyon, France
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3
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Yadav M, Atala A, Lu B. Developing all-in-one virus-like particles for Cas9 mRNA/single guide RNA co-delivery and aptamer-containing lentiviral vectors for improved gene expression. Int J Biol Macromol 2022; 209:1260-1270. [PMID: 35461863 DOI: 10.1016/j.ijbiomac.2022.04.114] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/13/2022] [Accepted: 04/15/2022] [Indexed: 01/10/2023]
Abstract
Lentiviral vectors (LVs) are widely used for delivering foreign genes for long-term expression. Recently, virus-like particles (VLPs) were developed for mRNA or ribonucleoprotein (RNP) delivery for short-term endonuclease expression. Generating large amount of LVs or VLPs is challenging. On the other hand, methods for using VLPs to co-deliver Cas9 mRNA and single guide RNA (sgRNA) are limited. Fusing aptamer-binding protein (ABP) to the N-terminus of HIV Gag protein is currently the successful way to develop hybrid particles for co-delivering Cas9 mRNA and sgRNA. The effects of modifying Gag protein this way on particle assembly are unknown. Previously we found that adding an ABP after the second zinc finger domain of nucleocapsid (NC) protein had minimal effects on particle assembly. Based on these observations, here we developed hybrid particles for Cas9 mRNA and sgRNA co-delivery with normal capsid assembly efficiency. We further improved LVs for integrated gene expression by including an aptamer sequence in lentiviral genomic RNA, which improved lentiviral particle production and enhanced LV genomic RNA packaging. In summary, here we describe the development of new all-in-one VLPs for co-delivery of Cas9 mRNA and sgRNA, and new LVs for enhanced vector production and gene expression.
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Affiliation(s)
- Manish Yadav
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Anthony Atala
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Baisong Lu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA.
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4
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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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5
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Lu Z, Yao X, Lyu P, Yadav M, Yoo K, Atala A, Lu B. Lentiviral Capsid-Mediated Streptococcus pyogenes Cas9 Ribonucleoprotein Delivery for Efficient and Safe Multiplex Genome Editing. CRISPR J 2021; 4:914-928. [PMID: 33733873 DOI: 10.1089/crispr.2020.0106] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Transient expression of the CRISPR-Cas9 machinery is desirable to reduce the risks of off-targets and immune responses. Electroporation of Cas9 ribonucleoproteins (RNPs) is the most common delivery method to achieve transient Cas9 expression. Recently, retroviral capsids have been used for delivering Streptococcus pyogenes Cas9 RNPs, in which Cas9 was fused to the viral proteins. The fusion strategy may cause relative low capsid assembly efficiency. We recently developed virus-like particles (VLPs) consisting of lentiviral capsid and Staphylococcus aureus Cas9 RNPs using the specific interactions between aptamer and aptamer-binding protein (ABP), and obtained near-normal capsid assembly efficiency. Here we test whether highly active Streptococcus pyogenes Cas9 (SpCas9) RNP VLPs can be generated with high efficiency by aptamer/ABP interaction. We found that by optimizing the locations and types of aptamer used for single guide RNA modification, highly active SpCas9 RNP VLPs can be generated efficiently. VLP-delivered SpCas9 generated lower off-target insertions and deletions than SpCas9 RNPs delivered by electroporation. VLPs containing Cas9 from different species and targeting multiple genes can be efficiently prepared in single-particle preparation. Multiple-target VLPs were more efficient than the combination of single-target VLPs for simultaneous targeting of multiple genes. Thus, in addition to better safety features, the Cas9 VLPs are especially suited for multiplex genome editing. In summary, our VLPs offer safe, efficient, and flexible multiplex genome editing.
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Affiliation(s)
- Zuyan Lu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Xingang Yao
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA.,School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, P. R. China
| | - Pin Lyu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Manish Yadav
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Kyung Yoo
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Anthony Atala
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
| | - Baisong Lu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA
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Kapaata A, Balinda SN, Xu R, Salazar MG, Herard K, Brooks K, Laban K, Hare J, Dilernia D, Kamali A, Ruzagira E, Mukasa F, Gilmour J, Salazar-Gonzalez JF, Yue L, Cotten M, Hunter E, Kaleebu P. HIV-1 Gag-Pol Sequences from Ugandan Early Infections Reveal Sequence Variants Associated with Elevated Replication Capacity. Viruses 2021; 13:v13020171. [PMID: 33498793 PMCID: PMC7912664 DOI: 10.3390/v13020171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 01/05/2023] Open
Abstract
The ability to efficiently establish a new infection is a critical property for human immunodeficiency virus type 1 (HIV-1). Although the envelope protein of the virus plays an essential role in receptor binding and internalization of the infecting virus, the structural proteins, the polymerase and the assembly of new virions may also play a role in establishing and spreading viral infection in a new host. We examined Ugandan viruses from newly infected patients and focused on the contribution of the Gag-Pol genes to replication capacity. A panel of Gag-Pol sequences generated using single genome amplification from incident HIV-1 infections were cloned into a common HIV-1 NL4.3 pol/env backbone and the influence of Gag-Pol changes on replication capacity was monitored. Using a novel protein domain approach, we then documented diversity in the functional protein domains across the Gag-Pol region and identified differences in the Gag-p6 domain that were frequently associated with higher in vitro replication.
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Affiliation(s)
- Anne Kapaata
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
| | - Sheila N. Balinda
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
| | - Rui Xu
- Emory University, Atlanta, GA 30322, USA; (R.X.); (K.H.); (K.B.); (D.D.); (L.Y.); (E.H.)
| | - Maria G. Salazar
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
| | - Kimberly Herard
- Emory University, Atlanta, GA 30322, USA; (R.X.); (K.H.); (K.B.); (D.D.); (L.Y.); (E.H.)
| | - Kelsie Brooks
- Emory University, Atlanta, GA 30322, USA; (R.X.); (K.H.); (K.B.); (D.D.); (L.Y.); (E.H.)
| | - Kato Laban
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
| | - Jonathan Hare
- Imperial College London, London SW7 2AZ, UK; (J.H.); (J.G.)
- International AIDS Vaccine Initiative (IAVI), New York, NY 10004, USA
| | - Dario Dilernia
- Emory University, Atlanta, GA 30322, USA; (R.X.); (K.H.); (K.B.); (D.D.); (L.Y.); (E.H.)
| | | | - Eugene Ruzagira
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
| | - Freddie Mukasa
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
| | - Jill Gilmour
- Imperial College London, London SW7 2AZ, UK; (J.H.); (J.G.)
- International AIDS Vaccine Initiative (IAVI), New York, NY 10004, USA
| | - Jesus F. Salazar-Gonzalez
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
| | - Ling Yue
- Emory University, Atlanta, GA 30322, USA; (R.X.); (K.H.); (K.B.); (D.D.); (L.Y.); (E.H.)
| | - Matthew Cotten
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
- Centre for Virus Research, MRC-University of Glasgow, Glasgow G61 1QH, UK
- Correspondence: ; Tel.: +25-6701-509-685
| | - Eric Hunter
- Emory University, Atlanta, GA 30322, USA; (R.X.); (K.H.); (K.B.); (D.D.); (L.Y.); (E.H.)
| | - Pontiano Kaleebu
- Medical Research Council, UVRI & LSTHM Uganda Research Unit, Plot 51–59, Entebbe, Uganda; (A.K.); (S.N.B.); (M.G.S.); (K.L.); (E.R.); (F.M.); (J.F.S.-G.); (P.K.)
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7
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Inositol phosphates promote HIV-1 assembly and maturation to facilitate viral spread in human CD4+ T cells. PLoS Pathog 2021; 17:e1009190. [PMID: 33476323 PMCID: PMC7853515 DOI: 10.1371/journal.ppat.1009190] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/02/2021] [Accepted: 11/26/2020] [Indexed: 11/19/2022] Open
Abstract
Gag polymerization with viral RNA at the plasma membrane initiates HIV-1 assembly. Assembly processes are inefficient in vitro but are stimulated by inositol (1,3,4,5,6) pentakisphosphate (IP5) and inositol hexakisphosphate (IP6) metabolites. Previous studies have shown that depletion of these inositol phosphate species from HEK293T cells reduced HIV-1 particle production but did not alter the infectivity of the resulting progeny virions. Moreover, HIV-1 substitutions bearing Gag/CA mutations ablating IP6 binding are noninfectious with destabilized viral cores. In this study, we analyzed the effects of cellular depletion of IP5 and IP6 on HIV-1 replication in T cells in which we disrupted the genes encoding the kinases required for IP6 generation, IP5 2-kinase (IPPK) and Inositol Polyphosphate Multikinase (IPMK). Knockout (KO) of IPPK from CEM and MT-4 cells depleted cellular IP6 in both T cell lines, and IPMK disruption reduced the levels of both IP5 and IP6. In the KO lines, HIV-1 spread was delayed relative to parental wild-type (WT) cells and was rescued by complementation. Virus release was decreased in all IPPK or IPMK KO lines relative to WT cells. Infected IPMK KO cells exhibited elevated levels of intracellular Gag protein, indicative of impaired particle assembly. IPMK KO compromised virus production to a greater extent than IPPK KO suggesting that IP5 promotes HIV-1 particle assembly in IPPK KO cells. HIV-1 particles released from infected IPPK or IPMK KO cells were less infectious than those from WT cells. These viruses exhibited partially cleaved Gag proteins, decreased virion-associated p24, and higher frequencies of aberrant particles, indicative of a maturation defect. Our data demonstrate that IP6 enhances the quantity and quality of virions produced from T cells, thereby preventing defects in HIV-1 replication.
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8
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Lyu P, Wang L, Lu B. Virus-Like Particle Mediated CRISPR/Cas9 Delivery for Efficient and Safe Genome Editing. Life (Basel) 2020; 10:366. [PMID: 33371215 PMCID: PMC7766694 DOI: 10.3390/life10120366] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/11/2020] [Accepted: 12/15/2020] [Indexed: 12/26/2022] Open
Abstract
The discovery of designer nucleases has made genome editing much more efficient than before. The designer nucleases have been widely used for mechanistic studies, animal model generation and gene therapy development. However, potential off-targets and host immune responses are issues still need to be addressed for in vivo uses, especially clinical applications. Short term expression of the designer nucleases is necessary to reduce both risks. Currently, various delivery methods are being developed for transient expression of designer nucleases including Zinc Finger Nuclease (ZNF), Transcription Activator-Like Effector Nuclease (TALEN) and Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated (CRISPR/Cas). Recently, virus-like particles are being used for gene editing. In this review, we will talk through commonly used genome editing nucleases, discuss gene editing delivery tools and review the latest literature using virus-like particles to deliver gene editing effectors.
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Affiliation(s)
- Pin Lyu
- School of Physical Education and Health, Hangzhou Normal University, Hangzhou 311121, China;
| | - Luxi Wang
- Department of Cancer Biology, Comprehensive Cancer Center of Wake Forest Baptist Medical Center, Winston-Salem, NC 27157, USA;
| | - Baisong Lu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA
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9
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Khan N, Chen X, Geiger JD. Role of Divalent Cations in HIV-1 Replication and Pathogenicity. Viruses 2020; 12:E471. [PMID: 32326317 PMCID: PMC7232465 DOI: 10.3390/v12040471] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/09/2020] [Accepted: 04/18/2020] [Indexed: 12/22/2022] Open
Abstract
Divalent cations are essential for life and are fundamentally important coordinators of cellular metabolism, cell growth, host-pathogen interactions, and cell death. Specifically, for human immunodeficiency virus type-1 (HIV-1), divalent cations are required for interactions between viral and host factors that govern HIV-1 replication and pathogenicity. Homeostatic regulation of divalent cations' levels and actions appear to change as HIV-1 infection progresses and as changes occur between HIV-1 and the host. In people living with HIV-1, dietary supplementation with divalent cations may increase HIV-1 replication, whereas cation chelation may suppress HIV-1 replication and decrease disease progression. Here, we review literature on the roles of zinc (Zn2+), iron (Fe2+), manganese (Mn2+), magnesium (Mg2+), selenium (Se2+), and copper (Cu2+) in HIV-1 replication and pathogenicity, as well as evidence that divalent cation levels and actions may be targeted therapeutically in people living with HIV-1.
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Affiliation(s)
| | | | - Jonathan D. Geiger
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA; (N.K.); (X.C.)
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10
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Watanabe SM, Strickland M, Tjandra N, Carter CA. RNA Binding Suppresses Tsg101 Recognition of Ub-Modified Gag and Facilitates Recruitment to the Plasma Membrane. Viruses 2020; 12:v12040447. [PMID: 32326417 PMCID: PMC7232412 DOI: 10.3390/v12040447] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/07/2020] [Accepted: 04/10/2020] [Indexed: 01/09/2023] Open
Abstract
The ESCRT-I factor Tsg101 is essential for sorting endocytic cargo and is exploited by viral pathogens to facilitate egress from cells. Both the nucleocapsid (NC) domain and p6 domain in HIV-1 Gag contribute to recruitment of the protein. However, the role of NC is unclear when the P(S/T)AP motif in p6 is intact, as the motif recruits Tsg101 directly. The zinc fingers in NC bind RNA and membrane and are critical for budding. Tsg101 can substitute for the distal ZnF (ZnF2) and rescue budding of a mutant made defective by deletion of this element. Here, we report that the ubiquitin (Ub) E2 variant (UEV) domain in Tsg101 binds tRNA in vitro. We confirmed that Tsg101 can substitute for ZnF2 when provided at the viral assembly site as a chimeric Gag-Tsg101 protein (Gag-ΔZnF2-Tsg101) and rescue budding. The UEV was not required in this context; however, mutation of the RNA binding determinants in UEV prevented Tsg101 recruitment from the cell interior when Gag and Tsg101 were co-expressed. The same Tsg101 mutations increased recognition of Gag-Ub, suggesting that tRNA and Ub compete for binding sites. This study identifies a novel Tsg101 binding partner that may contribute to its function in recognition of Ub-modified cargo.
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Affiliation(s)
- Susan M. Watanabe
- Department of Microbiology & Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794-5222, USA;
| | - Madeleine Strickland
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Nico Tjandra
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA;
- Correspondence: (N.T.); (C.A.C.); Tel.: +1-631-632-8801 (C.A.C.)
| | - Carol A. Carter
- Department of Microbiology & Immunology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794-5222, USA;
- Correspondence: (N.T.); (C.A.C.); Tel.: +1-631-632-8801 (C.A.C.)
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11
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Abeyratne-Perera HK, Ogharandukun E, Chandran PL. Complex-type N-glycans on VSV-G pseudotyped HIV exhibit 'tough' sialic and 'brittle' mannose self-adhesions. SOFT MATTER 2019; 15:4525-4540. [PMID: 31099376 DOI: 10.1039/c9sm00579j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The complex-type glycan shields of eukaryotic cells have a core layer of mannose residues buried under tiers of sugars that end with sialic acid (SA) residues. We investigate if the self-latching of mannose residues, earlier reported in pure monolayer studies, also manifests in the setting of a complex-type glycan shield. Would distal SA residues impede access to the mannose core? The interactions of mannobiose-, SA-, and lactose-coated probes with the complex-type VSV-G glycan shield on an HIV pseudovirus were studied with force-spectroscopy and gold-nanoparticle solutions. In force spectroscopy, the sugar probes can be forced to sample the depths of the glycan shield, whereas with sugar-coated nanoparticles, only interactions permitted by freely-diffusive contact occur. Deep-indentation mechanics was performed to verify the inferred structure of the engineered virus and to isolate the glycan shield layer for subsequent interaction studies. The adhesion between the sugar-probes and complex-type glycan shield was deconvoluted by comparing against the cross- and self- adhesions between the sugars in pure monolayers. Results from complementing systems were consistent with mannobiose-coated probes latching to the mannose core in the glycan shield, unhindered by the SA and distal sugars, with a short-range 'brittle' release of adhesion resulting in tightly coated viruses. SA-Coated probes, however, adhere to the terminal SA layer of a glycan shield with long-range and mechanically 'tough' adhesions resulting in large-scale virus aggregation. Lactose-coated probes exhibit ill-defined adherence to sialic residues. The selection and positioning of sugars within a glycan shield can influence how carbohydrate surfaces of different composition adhere.
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Affiliation(s)
- Hashanthi K Abeyratne-Perera
- Biochemistry and Molecular Biology Department, College of Medicine, 1011 LK Downing Hall 2300 6th Street, NW, Howard University, Washington, DC 20059, USA.
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12
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Lu B, Javidi-Parsijani P, Makani V, Mehraein-Ghomi F, Sarhan WM, Sun D, Yoo KW, Atala ZP, Lyu P, Atala A. Delivering SaCas9 mRNA by lentivirus-like bionanoparticles for transient expression and efficient genome editing. Nucleic Acids Res 2019; 47:e44. [PMID: 30759231 PMCID: PMC6486560 DOI: 10.1093/nar/gkz093] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 12/21/2022] Open
Abstract
The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system discovered using bacteria has been repurposed for genome editing in human cells. Transient expression of the editor proteins (e.g. Cas9 protein) is desirable to reduce the risk of mutagenesis from off-target activity. Using the specific interaction between bacteriophage RNA-binding proteins and their RNA aptamers, we developed a system able to package up to 100 copies of Staphylococcus aureus Cas9 (SaCas9) mRNA in each lentivirus-like bionanoparticle (LVLP). The SaCas9 LVLPs mediated transient SaCas9 expression and achieved highly efficient genome editing in the presence of guide RNA. Lower off-target rates occurred in cells transduced with LVLPs containing SaCas9 mRNA, compared with cells transduced with adeno-associated virus or lentivirus expressing SaCas9. Our LVLP system may be useful for efficiently delivering Cas9 mRNA to cell lines and primary cells for in vitro and in vivo gene editing applications.
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Affiliation(s)
- Baisong Lu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Parisa Javidi-Parsijani
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Vishruti Makani
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Farideh Mehraein-Ghomi
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Walaa Mohamed Sarhan
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Dongjun Sun
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Kyung Whan Yoo
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Zachary P Atala
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Pin Lyu
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
| | - Anthony Atala
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Winston-Salem, NC, USA
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13
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El Meshri SE, Boutant E, Mouhand A, Thomas A, Larue V, Richert L, Vivet-Boudou V, Mély Y, Tisné C, Muriaux D, de Rocquigny H. The NC domain of HIV-1 Gag contributes to the interaction of Gag with TSG101. Biochim Biophys Acta Gen Subj 2018; 1862:1421-1431. [PMID: 29571744 DOI: 10.1016/j.bbagen.2018.03.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/20/2018] [Accepted: 03/19/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND HIV-1 Gag polyprotein orchestrates the assembly of viral particles. Its C-terminus consists of the nucleocapsid (NC) domain that interacts with RNA, and the p6 domain containing the PTAP motif that binds the cellular ESCRT factor TSG101 and ALIX. Deletion of the NC domain of Gag (GagNC) results in defective Gag assembly, a decrease in virus production and, thus probably affects recruitment of the ESCRT machinery. To investigate the role of GagNC in this recruitment, we analysed its impact on TSG101 and ALIX localisations and interactions in cells expressing Gag. METHODS Cells expressing mCherry-Gag or derivatives, alone or together with eGFP-TSG101 or eGFP-ALIX, were analysed by confocal microscopy and FLIM-FRET. Chemical shift mapping between TSG101-UEV motif and Gag C-terminus was performed by NMR. RESULTS We show that deletion of NC or of its two zinc fingers decreases the amount of Gag-TSG101 interacting complexes in cells. These findings are supported by NMR data showing chemical shift perturbations in the NC domain in- and outside - of the zinc finger elements upon TSG101 binding. The NMR data further identify a large stretch of amino acids within the p6 domain directly interacting with TSG101. CONCLUSION The NC zinc fingers and p6 domain of Gag participate in the formation of the Gag-TSG101 complex and in its cellular localisation. GENERAL SIGNIFICANCE This study illustrates that the NC and p6 domains cooperate in the interaction with TSG101 during HIV-1 budding. In addition, details on the Gag-TSG101 complex were obtained by combining two high resolution biophysical techniques.
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Affiliation(s)
- Salah Edin El Meshri
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401 Illkirch Cedex, France
| | - Emmanuel Boutant
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401 Illkirch Cedex, France
| | - Assia Mouhand
- Laboratoire de Cristallographie et RMN biologiques, UMR 8015, CNRS, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France; Laboratoire d'Expression génétique microbienne, IBPC, UMR 8261, CNRS, Université Paris Diderot, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Audrey Thomas
- Membrane Domains and Viral Assembly, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, CNRS, UMR9004, 1919 route de Mende, 34293 Montpellier cedex 5, France
| | - Valéry Larue
- Laboratoire de Cristallographie et RMN biologiques, UMR 8015, CNRS, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Ludovic Richert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401 Illkirch Cedex, France
| | - Valérie Vivet-Boudou
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 15 Rue R. Descartes, 67084 Strasbourg Cedex, France
| | - Yves Mély
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401 Illkirch Cedex, France
| | - Carine Tisné
- Laboratoire de Cristallographie et RMN biologiques, UMR 8015, CNRS, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France; Laboratoire d'Expression génétique microbienne, IBPC, UMR 8261, CNRS, Université Paris Diderot, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Delphine Muriaux
- Membrane Domains and Viral Assembly, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, CNRS, UMR9004, 1919 route de Mende, 34293 Montpellier cedex 5, France.
| | - Hugues de Rocquigny
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74, Route du Rhin, 67401 Illkirch Cedex, France; Morphogenèse et Antigénicité du VIH et des Virus des Hépatites, Inserm - U1259 MAVIVH, 10 boulevard Tonnellé - BP 3223, 37032 Tours Cedex 1 -, France.
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14
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Wang C, Timmons CL, Shao Q, Kinlock BL, Turner TM, Iwamoto A, Zhang H, Liu H, Liu B. GB virus type C E2 protein inhibits human immunodeficiency virus type 1 Gag assembly by downregulating human ADP-ribosylation factor 1. Oncotarget 2016; 6:43293-309. [PMID: 26675377 PMCID: PMC4791233 DOI: 10.18632/oncotarget.6537] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 11/21/2015] [Indexed: 12/28/2022] Open
Abstract
GB virus type C (GBV-C) glycoprotein E2 protein disrupts HIV-1 assembly and release by inhibiting Gag plasma membrane targeting, however the mechanism by which the GBV-C E2 inhibits Gag trafficking remains unclear. In the present study, we identified ADP-ribosylation factor 1 (ARF1) contributed to the inhibitory effect of GBV-C E2 on HIV-1 Gag membrane targeting. Expression of GBV-C E2 decreased ARF1 expression in a proteasomal degradation-dependent manner. The restoration of ARF1 expression rescued the HIV-1 Gag processing and membrane targeting defect imposed by GBV-C E2. In addition, GBV-C E2 expression also altered Golgi morphology and suppressed protein traffic through the secretory pathway, which are all consistent with a phenotype of disrupting the function of ARF1 protein. Thus, our results indicate that GBV-C E2 inhibits HIV-1 assembly and release by decreasing ARF1, and may provide insights regarding GBV-C E2's potential for a new therapeutic approach for treating HIV-1.
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Affiliation(s)
- Chenliang Wang
- Center for AIDS Health Disparities Research, Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee, USA.,Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Department of Clinical Laboratory, Guangdong Institute of Gastroenterology and The Sixth Affiliated Hospital, Institute of Human Virology and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Christine L Timmons
- Center for AIDS Health Disparities Research, Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee, USA
| | - Qiujia Shao
- Center for AIDS Health Disparities Research, Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee, USA
| | - Ballington L Kinlock
- Center for AIDS Health Disparities Research, Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee, USA
| | - Tiffany M Turner
- Center for AIDS Health Disparities Research, Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee, USA
| | - Aikichi Iwamoto
- Division of Infectious Diseases, Advanced Clinical Research Center, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Hui Zhang
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Department of Clinical Laboratory, Guangdong Institute of Gastroenterology and The Sixth Affiliated Hospital, Institute of Human Virology and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Huanliang Liu
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Department of Clinical Laboratory, Guangdong Institute of Gastroenterology and The Sixth Affiliated Hospital, Institute of Human Virology and Key Laboratory of Tropical Disease Control of Ministry of Education, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Bindong Liu
- Center for AIDS Health Disparities Research, Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee, USA
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15
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Ferrer M, Clerté C, Chamontin C, Basyuk E, Lainé S, Hottin J, Bertrand E, Margeat E, Mougel M. Imaging HIV-1 RNA dimerization in cells by multicolor super-resolution and fluctuation microscopies. Nucleic Acids Res 2016; 44:7922-34. [PMID: 27280976 PMCID: PMC5027490 DOI: 10.1093/nar/gkw511] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/27/2016] [Indexed: 11/15/2022] Open
Abstract
Dimerization is a unique and vital characteristic of retroviral genomes. It is commonly accepted that genomic RNA (gRNA) must be dimeric at the plasma membrane of the infected cells to be packaged during virus assembly. However, where, when and how HIV-1 gRNA find each other and dimerize in the cell are long-standing questions that cannot be answered using conventional approaches. Here, we combine two state-of-the-art, multicolor RNA labeling strategies with two single-molecule microscopy technologies to address these questions. We used 3D-super-resolution structured illumination microscopy to analyze and quantify the spatial gRNA association throughout the cell and monitored the dynamics of RNA-RNA complexes in living-cells by cross-correlation fluctuation analysis. These sensitive and complementary approaches, combined with trans-complementation experiments, reveal for the first time the presence of interacting gRNA in the cytosol, a challenging observation due to the low frequency of these events and their dilution among the bulk of other RNAs, and allow the determination of the subcellular orchestration of the HIV-1 dimerization process.
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Affiliation(s)
- Mireia Ferrer
- Centre d'études d'agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Caroline Clerté
- CNRS UMR5048, Centre de Biochimie Structurale, 29 rue de Navacelles, 34090 Montpellier, France INSERM U1054, 34090 Montpellier, France Université de Montpellier, 34090 Montpellier, France
| | - Célia Chamontin
- Centre d'études d'agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Eugenia Basyuk
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS UMR 5535, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Sébastien Lainé
- Centre d'études d'agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Jérome Hottin
- CNRS UMR5048, Centre de Biochimie Structurale, 29 rue de Navacelles, 34090 Montpellier, France INSERM U1054, 34090 Montpellier, France Université de Montpellier, 34090 Montpellier, France
| | - Edouard Bertrand
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS UMR 5535, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Emmanuel Margeat
- CNRS UMR5048, Centre de Biochimie Structurale, 29 rue de Navacelles, 34090 Montpellier, France INSERM U1054, 34090 Montpellier, France Université de Montpellier, 34090 Montpellier, France
| | - Marylène Mougel
- Centre d'études d'agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
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16
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Racine PJ, Chamontin C, de Rocquigny H, Bernacchi S, Paillart JC, Mougel M. Requirements for nucleocapsid-mediated regulation of reverse transcription during the late steps of HIV-1 assembly. Sci Rep 2016; 6:27536. [PMID: 27273064 PMCID: PMC4895152 DOI: 10.1038/srep27536] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 05/13/2016] [Indexed: 12/19/2022] Open
Abstract
HIV-1 is a retrovirus replicating within cells by reverse transcribing its genomic RNA (gRNA) into DNA. Within cells, virus assembly requires the structural Gag proteins with few accessory proteins, notably the viral infectivity factor (Vif) and two copies of gRNA as well as cellular factors to converge to the plasma membrane. In this process, the nucleocapsid (NC) domain of Gag binds to the packaging signal of gRNA which consists of a series of stem-loops (SL1-SL3) ensuring gRNA selection and packaging into virions. Interestingly, mutating NC activates a late-occurring reverse transcription (RT) step in producer cells, leading to the release of DNA-containing HIV-1 particles. In order to decipher the molecular mechanism regulating this late RT, we explored the role of several key partners of NC, such as Vif, gRNA and the cellular cytidine deaminase APOBEC3G that restricts HIV-1 infection by targeting the RT. By studying combinations of deletions of these putative players, we revealed that NC, SL1-SL3 and in lesser extent Vif, but not APOBEC3G, interplay regulates the late RT.
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Affiliation(s)
- Pierre-Jean Racine
- Centre d'études d’agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Célia Chamontin
- Centre d'études d’agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
| | - Hugues de Rocquigny
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Faculté de Pharmacie, Université de Strasbourg, 74 Route du Rhin, 67401, Illkirch Cedex, France
| | - Serena Bernacchi
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084, Strasbourg, France
| | - Jean-Christophe Paillart
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, 15 rue René Descartes, 67084, Strasbourg, France
| | - Marylène Mougel
- Centre d'études d’agents pathogènes et biotechnologies pour la santé, CPBS-CNRS, Université de Montpellier, 1919 Route de Mende, 34293 Montpellier, France
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Abstract
Long terminal repeat (LTR) retrotransposons constitute significant fractions of many eukaryotic genomes. Two ancient families are Ty1/Copia (Pseudoviridae) and Ty3/Gypsy (Metaviridae). The Ty3/Gypsy family probably gave rise to retroviruses based on the domain order, similarity of sequences, and the envelopes encoded by some members. The Ty3 element of Saccharomyces cerevisiae is one of the most completely characterized elements at the molecular level. Ty3 is induced in mating cells by pheromone stimulation of the mitogen-activated protein kinase pathway as cells accumulate in G1. The two Ty3 open reading frames are translated into Gag3 and Gag3-Pol3 polyprotein precursors. In haploid mating cells Gag3 and Gag3-Pol3 are assembled together with Ty3 genomic RNA into immature virus-like particles in cellular foci containing RNA processing body proteins. Virus-like particle Gag3 is then processed by Ty3 protease into capsid, spacer, and nucleocapsid, and Gag3-Pol3 into those proteins and additionally, protease, reverse transcriptase, and integrase. After haploid cells mate and become diploid, genomic RNA is reverse transcribed into cDNA. Ty3 integration complexes interact with components of the RNA polymerase III transcription complex resulting in Ty3 integration precisely at the transcription start site. Ty3 activation during mating enables proliferation of Ty3 between genomes and has intriguing parallels with metazoan retrotransposon activation in germ cell lineages. Identification of nuclear pore, DNA replication, transcription, and repair host factors that affect retrotransposition has provided insights into how hosts and retrotransposons interact to balance genome stability and plasticity.
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18
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Kim MJ, Kim SH, Park JA, Yu KL, Jang SI, Kim BS, Lee ES, You JC. Identification and characterization of a new type of inhibitor against the human immunodeficiency virus type-1 nucleocapsid protein. Retrovirology 2015; 12:90. [PMID: 26545586 PMCID: PMC4636002 DOI: 10.1186/s12977-015-0218-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 10/22/2015] [Indexed: 01/18/2023] Open
Abstract
Background The human immunodeficiency virus type-1 (HIV-1) nucleocapsid protein (NC) is an essential and multifunctional protein involved in multiple stages of the viral life cycle such as reverse transcription, integration of proviral DNA, and especially genome RNA packaging. For this reason, it has been considered as an attractive target for the development of new anti-HIV drugs. Although a number of inhibitors of NC have been reported thus far, the search for NC-specific and functional inhibitor(s) with a good antiviral activity continues. Results In this study, we report the identification of A1752, a small molecule with inhibitory action against HIV-1 NC, which shows a strong antiviral efficacy and an IC50 around 1 μM. A1752 binds directly to HIV-1 NC, thereby inhibiting specific chaperone functions of NC including Psi RNA dimerization and complementary trans-activation response element (cTAR) DNA destabilization, and it also disrupts the proper Gag processing. Further analysis of the mechanisms of action of A1752 also showed that it generates noninfectious viral particles with defects in uncoating and reverse transcription in the infected cells. Conclusions These results demonstrate that A1752 is a specific and functional inhibitor of NC with a novel mode of action and good antiviral efficacy. Thus, this agent provides a new type of anti-HIV NC inhibitor candidate for further drug development. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0218-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Seon Hee Kim
- Avixgen Inc., Seoul, 137-701, Korea. .,National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seoul, 137-701, Korea.
| | | | - Kyung Lee Yu
- National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seoul, 137-701, Korea.
| | - Soo In Jang
- National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seoul, 137-701, Korea.
| | | | - Eun Soo Lee
- National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seoul, 137-701, Korea.
| | - Ji Chang You
- Avixgen Inc., Seoul, 137-701, Korea. .,National Research Laboratory of Molecular Virology, Department of Pathology, School of Medicine, The Catholic University of Korea, Seoul, 137-701, Korea.
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19
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Hendrix J, Baumgärtel V, Schrimpf W, Ivanchenko S, Digman MA, Gratton E, Kräusslich HG, Müller B, Lamb DC. Live-cell observation of cytosolic HIV-1 assembly onset reveals RNA-interacting Gag oligomers. J Cell Biol 2015; 210:629-46. [PMID: 26283800 PMCID: PMC4539982 DOI: 10.1083/jcb.201504006] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Analysis of the cytosolic HIV-1 Gag fraction in live cells via advanced fluctuation imaging methods reveals potential nucleation steps before membrane-assisted Gag assembly. Assembly of the Gag polyprotein into new viral particles in infected cells is a crucial step in the retroviral replication cycle. Currently, little is known about the onset of assembly in the cytosol. In this paper, we analyzed the cytosolic HIV-1 Gag fraction in real time in live cells using advanced fluctuation imaging methods and thereby provide detailed insights into the complex relationship between cytosolic Gag mobility, stoichiometry, and interactions. We show that Gag diffuses as a monomer on the subsecond timescale with severely reduced mobility. Reduction of mobility is associated with basic residues in its nucleocapsid (NC) domain, whereas capsid (CA) and matrix (MA) domains do not contribute significantly. Strikingly, another diffusive Gag species was observed on the seconds timescale that oligomerized in a concentration-dependent manner. Both NC- and CA-mediated interactions strongly assist this process. Our results reveal potential nucleation steps of cytosolic Gag fractions before membrane-assisted Gag assembly.
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Affiliation(s)
- Jelle Hendrix
- Physical Chemistry, Department of Chemistry, Ludwig Maximilian University of Munich, D-81377 Munich, Germany NanoSystems Initiative Munich (NIM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Munich Center for Integrated Protein Science (CiPSM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Center for Nanoscience (CeNS), Ludwig Maximilian University of Munich, D-81377 Munich, Germany
| | - Viola Baumgärtel
- Physical Chemistry, Department of Chemistry, Ludwig Maximilian University of Munich, D-81377 Munich, Germany NanoSystems Initiative Munich (NIM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Munich Center for Integrated Protein Science (CiPSM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Center for Nanoscience (CeNS), Ludwig Maximilian University of Munich, D-81377 Munich, Germany
| | - Waldemar Schrimpf
- Physical Chemistry, Department of Chemistry, Ludwig Maximilian University of Munich, D-81377 Munich, Germany NanoSystems Initiative Munich (NIM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Munich Center for Integrated Protein Science (CiPSM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Center for Nanoscience (CeNS), Ludwig Maximilian University of Munich, D-81377 Munich, Germany
| | - Sergey Ivanchenko
- Physical Chemistry, Department of Chemistry, Ludwig Maximilian University of Munich, D-81377 Munich, Germany NanoSystems Initiative Munich (NIM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Munich Center for Integrated Protein Science (CiPSM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Center for Nanoscience (CeNS), Ludwig Maximilian University of Munich, D-81377 Munich, Germany
| | - Michelle A Digman
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697 Development Biology Center Optical Biology Core Facility, University of California, Irvine, Irvine, CA 92697
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92697 Development Biology Center Optical Biology Core Facility, University of California, Irvine, Irvine, CA 92697
| | - Hans-Georg Kräusslich
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, D-69120 Heidelberg, Germany
| | - Barbara Müller
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, D-69120 Heidelberg, Germany
| | - Don C Lamb
- Physical Chemistry, Department of Chemistry, Ludwig Maximilian University of Munich, D-81377 Munich, Germany NanoSystems Initiative Munich (NIM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Munich Center for Integrated Protein Science (CiPSM), Ludwig Maximilian University of Munich, D-81377 Munich, Germany Center for Nanoscience (CeNS), Ludwig Maximilian University of Munich, D-81377 Munich, Germany
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Mori M, Kovalenko L, Lyonnais S, Antaki D, Torbett BE, Botta M, Mirambeau G, Mély Y. Nucleocapsid Protein: A Desirable Target for Future Therapies Against HIV-1. Curr Top Microbiol Immunol 2015; 389:53-92. [PMID: 25749978 PMCID: PMC7122173 DOI: 10.1007/82_2015_433] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The currently available anti-HIV-1 therapeutics is highly beneficial to infected patients. However, clinical failures occur as a result of the ability of HIV-1 to rapidly mutate. One approach to overcome drug resistance is to target HIV-1 proteins that are highly conserved among phylogenetically distant viral strains and currently not targeted by available therapies. In this respect, the nucleocapsid (NC) protein, a zinc finger protein, is particularly attractive, as it is highly conserved and plays a central role in virus replication, mainly by interacting with nucleic acids. The compelling rationale for considering NC as a viable drug target is illustrated by the fact that point mutants of this protein lead to noninfectious viruses and by the inability to select viruses resistant to a first generation of anti-NC drugs. In our review, we discuss the most relevant properties and functions of NC, as well as recent developments of small molecules targeting NC. Zinc ejectors show strong antiviral activity, but are endowed with a low therapeutic index due to their lack of specificity, which has resulted in toxicity. Currently, they are mainly being investigated for use as topical microbicides. Greater specificity may be achieved by using non-covalent NC inhibitors (NCIs) targeting the hydrophobic platform at the top of the zinc fingers or key nucleic acid partners of NC. Within the last few years, innovative methodologies have been developed to identify NCIs. Though the antiviral activity of the identified NCIs needs still to be improved, these compounds strongly support the druggability of NC and pave the way for future structure-based design and optimization of efficient NCIs.
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Affiliation(s)
- Mattia Mori
- Dipartimento di Biotecnologie Chimica e Farmacia, Università degli Studi di Siena, via A. Moro 2, 53100, Siena, Italy
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21
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Adjili S, Favier A, Fargier G, Thomas A, Massin J, Monier K, Favard C, Vanbelle C, Bruneau S, Peyriéras N, Andraud C, Muriaux D, Charreyre MT. Biocompatible photoresistant far-red emitting, fluorescent polymer probes, with near-infrared two-photon absorption, for living cell and zebrafish embryo imaging. Biomaterials 2015; 46:70-81. [DOI: 10.1016/j.biomaterials.2014.12.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/29/2014] [Accepted: 12/20/2014] [Indexed: 12/12/2022]
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22
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Role of the nucleocapsid domain in HIV-1 Gag oligomerization and trafficking to the plasma membrane: a fluorescence lifetime imaging microscopy investigation. J Mol Biol 2015; 427:1480-1494. [PMID: 25644662 DOI: 10.1016/j.jmb.2015.01.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/26/2015] [Accepted: 01/27/2015] [Indexed: 11/20/2022]
Abstract
The Pr55 Gag of human immunodeficiency virus type 1 orchestrates viral particle assembly in producer cells, which requires the genomic RNA and a lipid membrane as scaffolding platforms. The nucleocapsid (NC) domain with its two invariant CCHC zinc fingers flanked by unfolded basic sequences is thought to direct genomic RNA selection, dimerization and packaging during virus assembly. To further investigate the role of NC domain, we analyzed the assembly of Gag with deletions in the NC domain in parallel with that of wild-type Gag using fluorescence lifetime imaging microscopy combined with Förster resonance energy transfer in HeLa cells. We found that, upon binding to nucleic acids, the NC domain promotes the formation of compact Gag oligomers in the cytoplasm. Moreover, the intracellular distribution of the population of oligomers further suggests that oligomers progressively assemble during their trafficking toward the plasma membrane (PM), but with no dramatic changes in their compact arrangement. This ultimately results in the accumulation at the PM of closely packed Gag oligomers that likely arrange in hexameric lattices, as revealed by the perfect match between the experimental Förster resonance energy transfer value and the one calculated from the structural model of Gag in immature viruses. The distal finger and flanking basic sequences, but not the proximal finger, appear to be essential for Gag oligomer compaction and membrane binding. Moreover, the full NC domain was found to be instrumental in the kinetics of Gag oligomerization and intracellular trafficking. These findings further highlight the key roles played by the NC domain in virus assembly.
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23
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Chamontin C, Rassam P, Ferrer M, Racine PJ, Neyret A, Lainé S, Milhiet PE, Mougel M. HIV-1 nucleocapsid and ESCRT-component Tsg101 interplay prevents HIV from turning into a DNA-containing virus. Nucleic Acids Res 2014; 43:336-47. [PMID: 25488808 PMCID: PMC4288153 DOI: 10.1093/nar/gku1232] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
HIV-1, the agent of the AIDS pandemic, is an RNA virus that reverse transcribes its RNA genome (gRNA) into DNA, shortly after its entry into cells. Within cells, retroviral assembly requires thousands of structural Gag proteins and two copies of gRNA as well as cellular factors, which converge to the plasma membrane in a finely regulated timeline. In this process, the nucleocapsid domain of Gag (GagNC) ensures gRNA selection and packaging into virions. Subsequent budding and virus release require the recruitment of the cellular ESCRT machinery. Interestingly, mutating GagNC results into the release of DNA-containing viruses, by promo-ting reverse transcription (RTion) prior to virus release, through an unknown mechanism. Therefore, we explored the biogenesis of these DNA-containing particles, combining live-cell total internal-reflection fluorescent microscopy, electron microscopy, trans-complementation assays and biochemical characterization of viral particles. Our results reveal that DNA virus production is the consequence of budding defects associated with Gag aggregation at the plasma membrane and deficiency in the recruitment of Tsg101, a key ESCRT-I component. Indeed, targeting Tsg101 to virus assembly sites restores budding, restricts RTion and favors RNA packaging into viruses. Altogether, our results highlight the role of GagNC in the spatiotemporal control of RTion, via an ESCRT-I-dependent mechanism.
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Affiliation(s)
- Célia Chamontin
- CPBS, UMR5236 CNRS, University of Montpellier, 34293 Montpellier, France
| | - Patrice Rassam
- Centre de Biochimie Structurale, UMR5048 CNRS, University of Montpellier, 34090 Montpellier, France
| | - Mireia Ferrer
- CPBS, UMR5236 CNRS, University of Montpellier, 34293 Montpellier, France
| | - Pierre-Jean Racine
- CPBS, UMR5236 CNRS, University of Montpellier, 34293 Montpellier, France
| | - Aymeric Neyret
- CPBS, UMR5236 CNRS, University of Montpellier, 34293 Montpellier, France
| | - Sébastien Lainé
- CPBS, UMR5236 CNRS, University of Montpellier, 34293 Montpellier, France
| | - Pierre-Emmanuel Milhiet
- Centre de Biochimie Structurale, UMR5048 CNRS, University of Montpellier, 34090 Montpellier, France U1054 INSERM, 30090 Montpellier, France
| | - Marylène Mougel
- CPBS, UMR5236 CNRS, University of Montpellier, 34293 Montpellier, France
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24
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Garg D, Torbett BE. Advances in targeting nucleocapsid-nucleic acid interactions in HIV-1 therapy. Virus Res 2014; 193:135-43. [PMID: 25026536 PMCID: PMC4252855 DOI: 10.1016/j.virusres.2014.07.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 07/02/2014] [Accepted: 07/03/2014] [Indexed: 11/16/2022]
Abstract
The continuing challenge of HIV-1 treatment resistance in patients creates a need for the development of new antiretroviral inhibitors. The HIV nucleocapsid (NC) protein is a potential therapeutic target. NC is necessary for viral RNA packaging and in the early stages of viral infection. The high level of NC amino acid conservation among all HIV-1 clades suggests a low tolerance for mutations. Thus, NC mutations that could arise during inhibitor treatment to provide resistance may render the virus less fit. Disruption of NC function provides a unique opportunity to strongly dampen replication at multiple points during the viral life cycle with a single inhibitor. Although NC exhibits desirable features for a potential antiviral target, the structural flexibility, size, and the presence of two zinc fingers makes small molecule targeting of NC a challenging task. In this review, we discuss the recent advances in strategies to develop inhibitors of NC function and present a perspective on potential novel approaches that may help to overcome some of the current challenges in the field.
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Affiliation(s)
- Divita Garg
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Bruce E Torbett
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
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25
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Tartour K, Appourchaux R, Gaillard J, Nguyen XN, Durand S, Turpin J, Beaumont E, Roch E, Berger G, Mahieux R, Brand D, Roingeard P, Cimarelli A. IFITM proteins are incorporated onto HIV-1 virion particles and negatively imprint their infectivity. Retrovirology 2014; 11:103. [PMID: 25422070 PMCID: PMC4251951 DOI: 10.1186/s12977-014-0103-y] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 11/04/2014] [Indexed: 12/22/2022] Open
Abstract
Background Interferon induced transmembrane proteins 1, 2 and 3 (IFITMs) belong to a family of highly related antiviral factors that have been shown to interfere with a large spectrum of viruses including Filoviruses, Coronaviruses, Influenza virus, Dengue virus and HIV-1. In all these cases, the reported mechanism of antiviral inhibition indicates that the pool of IFITM proteins present in target cells blocks incoming viral particles in endosomal vesicles where they are subsequently degraded. Results In this study, we describe an additional mechanism through which IFITMs block HIV-1. In virus-producing cells, IFITMs coalesce with forming virions and are incorporated into viral particles. Expression of IFITMs during virion assembly leads to the production of virion particles of decreased infectivity that are mostly affected during entry in target cells. This mechanism of inhibition is exerted against different retroviruses and does not seem to be dependent on the type of Envelope present on retroviral particles. Conclusions The results described here identify a novel mechanism through which IFITMs affect HIV-1 infectivity during the late phases of the viral life cycle. Put in the context of data obtained by other laboratories, these results indicate that IFITMs can target HIV at two distinct moments of its life cycle, in target cells as well as in virus-producing cells. These results raise the possibility that IFITMs could similarly affect distinct steps of the life cycle of a number of other viruses. Electronic supplementary material The online version of this article (doi:10.1186/s12977-014-0103-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kevin Tartour
- CIRI, Centre International de Recherche en Infectiologie, Lyon, F69364, France. .,INSERM, U1111, 46 Allée d'Italie, Lyon, F69364, France. .,Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, F69364, France. .,CNRS, UMR5308, 46 Allée d'Italie, Lyon, F69364, France. .,University of Lyon, Lyon I, UMS3444/US8 BioSciences Gerland, Lyon, F69364, France.
| | - Romain Appourchaux
- CIRI, Centre International de Recherche en Infectiologie, Lyon, F69364, France. .,INSERM, U1111, 46 Allée d'Italie, Lyon, F69364, France. .,Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, F69364, France. .,CNRS, UMR5308, 46 Allée d'Italie, Lyon, F69364, France. .,University of Lyon, Lyon I, UMS3444/US8 BioSciences Gerland, Lyon, F69364, France.
| | - Julien Gaillard
- Plateforme des Microscopies, PPF ASB, Université F. Rabelais et CHRU de Tours, Tours, France.
| | - Xuan-Nhi Nguyen
- CIRI, Centre International de Recherche en Infectiologie, Lyon, F69364, France. .,INSERM, U1111, 46 Allée d'Italie, Lyon, F69364, France. .,Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, F69364, France. .,CNRS, UMR5308, 46 Allée d'Italie, Lyon, F69364, France. .,University of Lyon, Lyon I, UMS3444/US8 BioSciences Gerland, Lyon, F69364, France.
| | - Stéphanie Durand
- CIRI, Centre International de Recherche en Infectiologie, Lyon, F69364, France. .,INSERM, U1111, 46 Allée d'Italie, Lyon, F69364, France. .,Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, F69364, France. .,CNRS, UMR5308, 46 Allée d'Italie, Lyon, F69364, France. .,University of Lyon, Lyon I, UMS3444/US8 BioSciences Gerland, Lyon, F69364, France.
| | - Jocelyn Turpin
- CIRI, Centre International de Recherche en Infectiologie, Lyon, F69364, France. .,INSERM, U1111, 46 Allée d'Italie, Lyon, F69364, France. .,Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, F69364, France. .,CNRS, UMR5308, 46 Allée d'Italie, Lyon, F69364, France. .,University of Lyon, Lyon I, UMS3444/US8 BioSciences Gerland, Lyon, F69364, France.
| | - Elodie Beaumont
- INSERM U966, Université F. Rabelais et CHRU de Tours, Tours, France.
| | - Emmanuelle Roch
- INSERM U966, Université F. Rabelais et CHRU de Tours, Tours, France.
| | - Gregory Berger
- CIRI, Centre International de Recherche en Infectiologie, Lyon, F69364, France. .,INSERM, U1111, 46 Allée d'Italie, Lyon, F69364, France. .,Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, F69364, France. .,CNRS, UMR5308, 46 Allée d'Italie, Lyon, F69364, France. .,University of Lyon, Lyon I, UMS3444/US8 BioSciences Gerland, Lyon, F69364, France. .,Present address: Department of Infectious Diseases, King's College London School of Medicine, London, SE1 9RT, UK.
| | - Renaud Mahieux
- CIRI, Centre International de Recherche en Infectiologie, Lyon, F69364, France. .,INSERM, U1111, 46 Allée d'Italie, Lyon, F69364, France. .,Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, F69364, France. .,CNRS, UMR5308, 46 Allée d'Italie, Lyon, F69364, France. .,University of Lyon, Lyon I, UMS3444/US8 BioSciences Gerland, Lyon, F69364, France.
| | - Denys Brand
- INSERM U966, Université F. Rabelais et CHRU de Tours, Tours, France.
| | - Philippe Roingeard
- Plateforme des Microscopies, PPF ASB, Université F. Rabelais et CHRU de Tours, Tours, France. .,INSERM U966, Université F. Rabelais et CHRU de Tours, Tours, France.
| | - Andrea Cimarelli
- CIRI, Centre International de Recherche en Infectiologie, Lyon, F69364, France. .,INSERM, U1111, 46 Allée d'Italie, Lyon, F69364, France. .,Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, Lyon, F69364, France. .,CNRS, UMR5308, 46 Allée d'Italie, Lyon, F69364, France. .,University of Lyon, Lyon I, UMS3444/US8 BioSciences Gerland, Lyon, F69364, France.
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26
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The HIV-1 nucleocapsid protein recruits negatively charged lipids to ensure its optimal binding to lipid membranes. J Virol 2014; 89:1756-67. [PMID: 25410868 DOI: 10.1128/jvi.02931-14] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED The HIV-1 Gag polyprotein precursor composed of the matrix (MA), capsid (CA), nucleocapsid (NC), and p6 domains orchestrates virus assembly via interactions between MA and the cell plasma membrane (PM) on one hand and NC and the genomic RNA on the other hand. As the Gag precursor can adopt a bent conformation, a potential interaction of the NC domain with the PM cannot be excluded during Gag assembly at the PM. To investigate the possible interaction of NC with lipid membranes in the absence of any interference from the other domains of Gag, we quantitatively characterized by fluorescence spectroscopy the binding of the mature NC protein to large unilamellar vesicles (LUVs) used as membrane models. We found that NC, either in its free form or bound to an oligonucleotide, was binding with high affinity (∼ 10(7) M(-1)) to negatively charged LUVs. The number of NC binding sites, but not the binding constant, was observed to decrease with the percentage of negatively charged lipids in the LUV composition, suggesting that NC and NC/oligonucleotide complexes were able to recruit negatively charged lipids to ensure optimal binding. However, in contrast to MA, NC did not exhibit a preference for phosphatidylinositol-(4,5)-bisphosphate. These results lead us to propose a modified Gag assembly model where the NC domain contributes to the initial binding of the bent form of Gag to the PM. IMPORTANCE The NC protein is a highly conserved nucleic acid binding protein that plays numerous key roles in HIV-1 replication. While accumulating evidence shows that NC either as a mature protein or as a domain of the Gag precursor also interacts with host proteins, only a few data are available on the possible interaction of NC with lipid membranes. Interestingly, during HIV-1 assembly, the Gag precursor is thought to adopt a bent conformation where the NC domain may interact with the plasma membrane. In this context, we quantitatively characterized the binding of NC, as a free protein or as a complex with nucleic acids, to lipid membranes and showed that the latter constitute a binding platform for NC. Taken together, our data suggest that the NC domain may play a role in the initial binding events of Gag to the plasma membrane during HIV-1 assembly.
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27
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Human APOBEC3F incorporation into human immunodeficiency virus type 1 particles. Virus Res 2014; 191:30-8. [PMID: 25038404 DOI: 10.1016/j.virusres.2014.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Revised: 07/07/2014] [Accepted: 07/07/2014] [Indexed: 11/21/2022]
Abstract
APOBEC3 proteins are a family of cytidine deaminases that exhibit broad antiretroviral activity. Among APOBEC3 proteins, APOBEC3G (hA3G) and APOBEC3F (hA3F) exhibit the most potent anti-HIV-1 activities. Although the incorporation of hA3F into virions is a prerequisite for exerting its antiviral function, the detail mechanism underlying remains incompletely understood. In this work, we present data showing that the nucleocapsid (NC) domain of HIV-1 Gag and a linker sequence between the two cytidine deaminase domains within hA3F, i.e., 104-156 amino acids, are required for viral packaging of hA3F. A detailed mapping study reveals that the cluster of basic residues surrounding the N-terminal zinc finger (ZF) and the linker region between the ZFs of HIV-1 NC play an important role in A3F incorporation, in addition, at least one of two ZFs is required. A hA3F fragment is able to compete with both hA3G and hA3F for viral incorporation, suggesting a common mechanism underlying virion encapsidation of hA3G and hA3F. Taken together, these results shed a light on the detail mechanism underlying viral incorporation of hA3F.
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28
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Role of the nucleocapsid region in HIV-1 Gag assembly as investigated by quantitative fluorescence-based microscopy. Virus Res 2014; 193:78-88. [PMID: 25016037 DOI: 10.1016/j.virusres.2014.06.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Revised: 06/17/2014] [Accepted: 06/17/2014] [Indexed: 11/19/2022]
Abstract
The Gag precursor of HIV-1, formed of the four proteic regions matrix (MA), capsid (CA), nucleocapsid (NC) and p6, orchestrates virus morphogenesis. This complex process relies on three major interactions, NC-RNA acting as a scaffold, CA-CA and MA-membrane that targets assembly to the plasma membrane (PM). The characterization of the molecular mechanism of retroviral assembly has extensively benefited from biochemical studies and more recently an important step forward was achieved with the use of fluorescence-based techniques and fluorescently labeled viral proteins. In this review, we summarize the findings obtained with such techniques, notably quantitative-based approaches, which highlight the role of the NC region in Gag assembly.
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29
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Retrospective on the all-in-one retroviral nucleocapsid protein. Virus Res 2014; 193:2-15. [PMID: 24907482 PMCID: PMC7114435 DOI: 10.1016/j.virusres.2014.05.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 05/11/2014] [Accepted: 05/11/2014] [Indexed: 01/08/2023]
Abstract
This retrospective reviews 30 years of research on the retroviral nucleocapsid protein (NC) focusing on HIV-1 NC. Originally considered as a non-specific nucleic-acid binding protein, NC has seminal functions in virus replication. Indeed NC turns out to be a all-in-one viral protein that chaperones viral DNA synthesis and integration, and virus formation. As a chaperone NC provides assistance to genetic recombination thus allowing the virus to escape the immune response and antiretroviral therapies against HIV-1.
This review aims at briefly presenting a retrospect on the retroviral nucleocapsid protein (NC), from an unspecific nucleic acid binding protein (NABP) to an all-in-one viral protein with multiple key functions in the early and late phases of the retrovirus replication cycle, notably reverse transcription of the genomic RNA and viral DNA integration into the host genome, and selection of the genomic RNA together with the initial steps of virus morphogenesis. In this context we will discuss the notion that NC protein has a flexible conformation and is thus a member of the growing family of intrinsically disordered proteins (IDPs) where disorder may account, at least in part, for its function as a nucleic acid (NA) chaperone and possibly as a protein chaperone vis-à-vis the viral DNA polymerase during reverse transcription. Lastly, we will briefly review the development of new anti-retroviral/AIDS compounds targeting HIV-1 NC because it represents an ideal target due to its multiple roles in the early and late phases of virus replication and its high degree of conservation.
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30
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Ouyang W, Okaine S, McPike MP, Lin Y, Borer PN. Probing the RNA Binding Surface of the HIV-1 Nucleocapsid Protein by Site-Directed Mutagenesis. Biochemistry 2013; 52:3358-68. [DOI: 10.1021/bi400125z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Wei Ouyang
- Graduate
Program in Structural Biology, Biochemistry, and Biophysics and ‡Department of
Chemistry, Syracuse University, Syracuse, New York 13244-4100, United States
| | - Stephen Okaine
- Graduate
Program in Structural Biology, Biochemistry, and Biophysics and ‡Department of
Chemistry, Syracuse University, Syracuse, New York 13244-4100, United States
| | - Mark P. McPike
- Graduate
Program in Structural Biology, Biochemistry, and Biophysics and ‡Department of
Chemistry, Syracuse University, Syracuse, New York 13244-4100, United States
| | - Yong Lin
- Graduate
Program in Structural Biology, Biochemistry, and Biophysics and ‡Department of
Chemistry, Syracuse University, Syracuse, New York 13244-4100, United States
| | - Philip N. Borer
- Graduate
Program in Structural Biology, Biochemistry, and Biophysics and ‡Department of
Chemistry, Syracuse University, Syracuse, New York 13244-4100, United States
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31
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Grover JR, Llewellyn GN, Soheilian F, Nagashima K, Veatch SL, Ono A. Roles played by capsid-dependent induction of membrane curvature and Gag-ESCRT interactions in tetherin recruitment to HIV-1 assembly sites. J Virol 2013; 87:4650-64. [PMID: 23408603 PMCID: PMC3624355 DOI: 10.1128/jvi.03526-12] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 02/04/2013] [Indexed: 12/17/2022] Open
Abstract
Tetherin/BST-2 (here called tetherin) is an antiviral protein that restricts release of diverse enveloped viruses from infected cells through physically tethering virus envelope and host plasma membrane. For HIV-1, specific recruitment of tetherin to assembly sites has been observed as its colocalization with the viral structural protein Gag or its accumulation in virus particles. Because of its broad range of targets, we hypothesized that tetherin is recruited through conserved features shared among various enveloped viruses, such as lipid raft association, membrane curvature, or ESCRT dependence. We observed that reduction of cellular cholesterol does not block tetherin anti-HIV-1 function, excluding an essential role for lipid rafts. In contrast, mutations in the capsid domain of Gag, which inhibit induction of membrane curvature, prevented tetherin-Gag colocalization detectable by confocal microscopy. Disruption of Gag-ESCRT interactions also inhibited tetherin-Gag colocalization when disruption was accomplished via amino acid substitutions in late domain motifs, expression of a dominant-negative Tsg101 derivative, or small interfering RNA (siRNA)-mediated depletion of Tsg101 or Alix. However, further analyses of these conditions by quantitative superresolution localization microscopy revealed that Gag-tetherin coclustering is significantly reduced but persists at intermediate levels. Notably, this residual tetherin recruitment was still sufficient for the full restriction of HIV-1 release. Unlike the late domain mutants, the capsid mutants defective in inducing membrane curvature showed little or no coclustering with tetherin in superresolution analyses. These results support a model in which both Gag-induced membrane curvature and Gag-ESCRT interactions promote tetherin recruitment, but the recruitment level achieved by the former is sufficient for full restriction.
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Affiliation(s)
| | - G. Nicholas Llewellyn
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Ferri Soheilian
- Electron Microscopy Laboratory, SAIC-Frederick, Inc., National Cancer Institute, Frederick, Maryland, USA
| | - Kunio Nagashima
- Electron Microscopy Laboratory, SAIC-Frederick, Inc., National Cancer Institute, Frederick, Maryland, USA
| | - Sarah L. Veatch
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan, USA
| | - Akira Ono
- Department of Microbiology and Immunology
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Yufenyuy EL, Aiken C. The NTD-CTD intersubunit interface plays a critical role in assembly and stabilization of the HIV-1 capsid. Retrovirology 2013; 10:29. [PMID: 23497318 PMCID: PMC3623829 DOI: 10.1186/1742-4690-10-29] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 02/18/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Lentiviruses exhibit a cone-shaped capsid composed of subunits of the viral CA protein. The intrinsic stability of the capsid is critical for HIV-1 infection, since both stabilizing and destabilizing mutations compromise viral infectivity. Structural studies have identified three intersubunit interfaces in the HIV-1 capsid, two of which have been previously studied by mutational analysis. In this present study we analyzed the role of a third interface, that which is formed between the amino terminal domain (NTD) and carboxyl terminal domain (CTD) of adjacent subunits. RESULTS We provided evidence for the presence of the NTD-CTD interface in HIV-1 particles by engineering intersubunit NTD-CTD disulfide crosslinks, resulting in accumulation of disulfide-linked oligomers up to hexamers. We also generated and characterized a panel of HIV-1 mutants containing substitutions at this interface. Some mutants showed processing defects and altered morphology from that of wild type, indicating that the interface is important for capsid assembly. Analysis of these mutants by transmission electron microscopy corroborated the importance of this interface in assembly. Other mutants exhibited quantitative changes in capsid stability, many with unstable capsids, and one mutant with a hyperstable capsid. Analysis of the mutants for their capacity to saturate TRIMCyp-mediated restriction in trans confirmed that the unstable mutants undergo premature uncoating in target cells. All but one of the mutants were markedly attenuated in replication owing to impaired reverse transcription in target cells. CONCLUSIONS Our results demonstrate that the NTD-CTD intersubunit interface is present in the mature HIV-1 capsid and is critical for proper capsid assembly and stability.
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Affiliation(s)
- Ernest L Yufenyuy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Chamontin C, Yu B, Racine PJ, Darlix JL, Mougel M. MoMuLV and HIV-1 nucleocapsid proteins have a common role in genomic RNA packaging but different in late reverse transcription. PLoS One 2012; 7:e51534. [PMID: 23236513 PMCID: PMC3517543 DOI: 10.1371/journal.pone.0051534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 11/05/2012] [Indexed: 11/25/2022] Open
Abstract
Retroviral nucleocapsid proteins harbor nucleic acid chaperoning activities that mostly rely on the N-terminal basic residues and the CCHC zinc finger motif. Such chaperoning is essential for virus replication, notably for genomic RNA selection and packaging in virions, and for reverse transcription of genomic RNA into DNA. Recent data revealed that HIV-1 nucleocapsid restricts reverse transcription during virus assembly--a process called late reverse transcription--suggesting a regulation between RNA packaging and late reverse transcription. Indeed, mutating the HIV-1 nucleocapsid basic residues or the two zinc fingers caused a reduction in RNA incorporated and an increase in newly made viral DNA in the mutant virions. MoMuLV nucleocapsid has an N-terminal basic region similar to HIV-1 nucleocapsid but a unique zinc finger. This prompted us to investigate whether the N-terminal basic residues and the zinc finger of MoMuLV and HIV-1 nucleocapsids play a similar role in genomic RNA packaging and late reverse transcription. To this end, we analyzed the genomic RNA and viral DNA contents of virions produced by cells transfected with MoMuLV molecular clones where the zinc finger was mutated or completely deleted or with a deletion of the N-terminal basic residues of nucleocapsid. All mutant virions showed a strong defect in genomic RNA content indicating that the basic residues and zinc finger are important for genomic RNA packaging. In contrast to HIV-1 nucleocapsid-mutants, the level of viral DNA in mutant MoMuLV virions was only slightly increased. These results confirm that the N-terminal basic residues and zinc finger of MoMuLV nucleocapsid are critical for genomic RNA packaging but, in contrast to HIV-1 nucleocapsid, they most probably do not play a role in the control of late reverse transcription. In addition, these results suggest that virus formation and late reverse transcription proceed according to distinct mechanisms for MuLV and HIV-1.
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Affiliation(s)
| | - Bing Yu
- UMR5236 CNRS, UM1,UM2, CPBS, Montpellier, France
| | | | - Jena-Luc Darlix
- UMR 7213 CNRS, Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie, Illkirch, France
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O'Carroll IP, Soheilian F, Kamata A, Nagashima K, Rein A. Elements in HIV-1 Gag contributing to virus particle assembly. Virus Res 2012; 171:341-5. [PMID: 23099087 DOI: 10.1016/j.virusres.2012.10.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 10/15/2012] [Accepted: 10/16/2012] [Indexed: 10/27/2022]
Abstract
The Gag polyprotein is the building block of retroviral particles and its expression is sufficient for assembly in cells. In HIV-1, nucleic acid (NA) is required for recombinant Gag molecules to assemble in a defined system in vitro. Experiments performed by Barklis and co-workers suggested that NA contributes to assembly by promoting Gag oligomerization. Gag is composed of four main domains: the matrix (MA), capsid (CA), nucleocapsid (NC), and p6 domains. We have recently shown that the SP1 linker, which lies between the CA and NC domains, assumes a helical structure at high, but not low, concentrations. We suggested that Gag oligomerization mediates assembly via an SP1-dependent conformational switch that exposes new interfaces for assembly. Although NA is required for assembly in vitro, deletion of NC, the main RNA-binding domain, does not eliminate particle formation in vivo; these particles lack NA. We hypothesized that alternative pathways that lead to Gag oligomerization or an increase in local Gag concentration, namely Gag-membrane or inter-protein interactions, rescue assembly in the absence of NC-RNA binding. We constructed mutants in which either Gag-membrane binding, the Gag dimer interface, or NC-RNA binding are disrupted. None of these mutants disables assembly. However, combined mutations in any two of these three classes render Gag completely unable to form virus-like particles. Thus, it seems, Gag utilizes at least three types of interactions to form oligomers and any two out of the three are sufficient for assembly.
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Affiliation(s)
- Ina P O'Carroll
- HIV Drug Resistance Program, National Cancer Institute, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
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35
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Clemens K, Bilanchone V, Beliakova-Bethell N, Larsen LSZ, Nguyen K, Sandmeyer S. Sequence requirements for localization and packaging of Ty3 retroelement RNA. Virus Res 2012; 171:319-31. [PMID: 23073180 DOI: 10.1016/j.virusres.2012.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 10/06/2012] [Accepted: 10/08/2012] [Indexed: 12/22/2022]
Abstract
Retroviruses and retrotransposons package genomic RNA into virus-like particles (VLPs) in a poorly understood process. Expression of the budding yeast retrotransposon Ty3 results in the formation of cytoplasmic Ty3 VLP assembly foci comprised of Ty3 RNA and proteins, and cellular factors associated with RNA processing body (PB) components, which modulate translation and effect nonsense-mediated decay (NMD). A series of Ty3 RNA variants were tested to understand the effects of read-through translation via programmed frameshifting on RNA localization and packaging into VLPs, and to identify the roles of coding and non-coding sequences in those processes. These experiments showed that a low level of read-through translation of the downstream open reading frame (as opposed to no translation or translation without frameshifting) is important for localization of full-length Ty3 RNA to foci. Ty3 RNA variants associated with PB components via independent determinants in the native Ty3 untranslated regions (UTRs) and in GAG3-POL3 sequences flanked by UTRs adapted from non-Ty3 transcripts. However, despite localization, RNAs containing GAG3-POL3 but lacking Ty3 UTRs were not packaged efficiently. Surprisingly, sequences within Ty3 UTRs, which bind the initiator tRNA(Met) proposed to provide the dimerization interface, were not required for packaging of full-length Ty3 RNA into VLPs. In summary, our results demonstrate that Gag3 is sufficient and required for localization and packaging of RNAs containing Ty3 UTRs and support a role for POL3 sequences, translation of which is attenuated by programmed frameshifting, in both localization and packaging of the Ty3 full-length gRNA.
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Affiliation(s)
- Kristina Clemens
- Department of Biological Chemistry, University of California, Irvine, CA 92697, USA
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36
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Parent LJ. New insights into the nuclear localization of retroviral Gag proteins. Nucleus 2012; 2:92-7. [PMID: 21738831 DOI: 10.4161/nucl.2.2.15018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 01/28/2011] [Accepted: 02/01/2011] [Indexed: 11/19/2022] Open
Abstract
Retroviruses assemble new virus particles that are released by budding from the plasma membranes of infected cells. Gag proteins, encoded by retroviruses, orchestrate the assembly of virus particles in close collaboration with host cell machinery. The earliest steps in retrovirus assembly-those immediately following synthesis of Gag on cytosolic ribosomes-are poorly understood. Rous sarcoma virus (RSV) offers a unique model system for dissecting these early steps because the RSV Gag protein undergoes transient nuclear trafficking prior to plasma membrane transport. Other Gag proteins, including those of human immunodeficiency virus (HIV), murine leukemia virus (MLV), foamy virus and retrotransposons in Schizosaccharomyces pombe and Drosophila, have also been detected in the nucleus, suggesting that nuclear trafficking of Gag proteins is a common property of retroviruses and retrotransposons. In addition to retroviruses, many structural proteins of unrelated viruses, including influenza M1, NEP and NP proteins,38 Borna disease virus N and P proteins28,56 and coronavirus N protein,23,57 undergo nuclear localization and bind viral RNAs to form viral ribonuclear protein (RNP) complexes that are exported from the nucleus for packaging into virus particles. Similarly, nuclear trafficking of the RSV Gag protein is required for efficient encapsidation of the viral genomic RNA (gRNA) into assembling virus particles.19 Recently, we reported that the viral RNA itself appears to be a key factor in controlling the nucleus/cytosol distribution of RSV Gag.22 Our data demonstrate that binding of RSV RNA to the Gag protein promotes Gag-CRM1-RanGTP binding, resulting in export of the retroviral RNP from the nucleus. We propose that association of the viral RNA induces a conformational change in Gag that reveals its nuclear export signal (NES) and prepares that complex for its journey to the plasma membrane for budding. This work challenges existing dogmas regarding the molecular basis of Gag-mediated selection of gRNA for packaging and may lead to novel paradigms for the mechanism of retroviral genome encapsidation.
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Affiliation(s)
- Leslie J Parent
- Department of Medicine, Penn State College of Medicine, Hershey, PA, USA.
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37
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Cytoplasmic utilization of human immunodeficiency virus type 1 genomic RNA is not dependent on a nuclear interaction with gag. J Virol 2012; 86:2990-3002. [PMID: 22258250 DOI: 10.1128/jvi.06874-11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In some retroviruses, such as Rous sarcoma virus and prototype foamy virus, Gag proteins are known to shuttle between the nucleus and the cytoplasm and are implicated in nuclear export of the viral genomic unspliced RNA (gRNA) for subsequent encapsidation. A similar function has been proposed for human immunodeficiency virus type 1 (HIV-1) Gag based on the identification of nuclear localization and export signals. However, the ability of HIV-1 Gag to transit through the nucleus has never been confirmed. In addition, the lentiviral Rev protein promotes efficient nuclear gRNA export, and previous reports indicate a cytoplasmic interaction between Gag and gRNA. Therefore, functional effects of HIV-1 Gag on gRNA and its usage were explored. Expression of gag in the absence of Rev was not able to increase cytoplasmic gRNA levels of subgenomic, proviral, or lentiviral vector constructs, and gene expression from genomic reporter plasmids could not be induced by Gag provided in trans. Furthermore, Gag lacking the reported nuclear localization and export signals was still able to mediate an efficient packaging process. Although small amounts of Gag were detectable in the nuclei of transfected cells, a Crm1-dependent nuclear export signal in Gag could not be confirmed. Thus, our study does not provide any evidence for a nuclear function of HIV-1 Gag. The encapsidation process of HIV-1 therefore clearly differs from that of Rous sarcoma virus and prototype foamy virus.
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38
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Balasubramaniam M, Freed EO. New insights into HIV assembly and trafficking. Physiology (Bethesda) 2012; 26:236-51. [PMID: 21841072 DOI: 10.1152/physiol.00051.2010] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Assembly and release of human immunodeficiency virus type 1 (HIV-1) particles is mediated by the viral Gag polyprotein precursor. Gag is synthesized in the cytosol and rapidly translocates to membrane to orchestrate particle production. The cell biology of HIV-1 Gag trafficking is currently one of the least understood aspects of HIV-1 replication. In this review, we highlight the current understanding of the cellular machinery involved in Gag trafficking and virus assembly.
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Affiliation(s)
- Muthukumar Balasubramaniam
- Virus-Cell Interaction Section, HIV Drug Resistance Program, National Cancer Institute, Frederick, Maryland, USA
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39
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Ivanyi-Nagy R, Darlix JL. Fuzziness in the Core of the Human Pathogenic Viruses HCV and HIV. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 725:142-58. [DOI: 10.1007/978-1-4614-0659-4_9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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40
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Wainberg MA, Cohen EA. Jean-Luc Darlix: Renaissance scientist and retrovirologist par excellence. Retrovirology 2011; 8:59. [PMID: 21767377 PMCID: PMC3152887 DOI: 10.1186/1742-4690-8-59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 07/18/2011] [Indexed: 11/10/2022] Open
Abstract
Jean-Luc Darlix was recently recognized with the first Retrovirology Lifetime Achievement Award on the occasion of his "retirement" symposium in Lyon.
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41
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Didierlaurent L, Racine PJ, Houzet L, Chamontin C, Berkhout B, Mougel M. Role of HIV-1 RNA and protein determinants for the selective packaging of spliced and unspliced viral RNA and host U6 and 7SL RNA in virus particles. Nucleic Acids Res 2011; 39:8915-27. [PMID: 21791531 PMCID: PMC3203606 DOI: 10.1093/nar/gkr577] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 06/27/2011] [Accepted: 06/28/2011] [Indexed: 01/22/2023] Open
Abstract
HIV-1 particles contain RNA species other than the unspliced viral RNA genome. For instance, viral spliced RNAs and host 7SL and U6 RNAs are natural components that are non-randomly incorporated. To understand the mechanism of packaging selectivity, we analyzed the content of a large panel of HIV-1 variants mutated either in the 5'UTR structures of the viral RNA or in the Gag-nucleocapsid protein (GagNC). In parallel, we determined whether the selection of host 7SL and U6 RNAs is dependent or not on viral RNA and/or GagNC. Our results reveal that the polyA hairpin in the 5'UTR is a major packaging determinant for both spliced and unspliced viral RNAs. In contrast, 5'UTR RNA structures have little influence on the U6 and 7SL RNAs, indicating that packaging of these host RNAs is independent of viral RNA packaging. Experiments with GagNC mutants indicated that the two zinc-fingers and N-terminal basic residues restrict the incorporation of the spliced RNAs, while favoring unspliced RNA packaging. GagNC through the zinc-finger motifs also restricts the packaging of 7SL and U6 RNAs. Thus, GagNC is a major contributor to the packaging selectivity. Altogether our results provide new molecular insight on how HIV selects distinct RNA species for incorporation into particles.
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Affiliation(s)
- L. Didierlaurent
- UMR5236 CNRS, UMI&II, CPBS, 1919 Rte de Mende, Montpellier, France, LMM, NIAID, NIH Bethesda, MD, USA and Laboratory of Experimental Virology, Department of Medical Microbiology (CINIMA), Amsterdam, The Netherlands
| | - P. J. Racine
- UMR5236 CNRS, UMI&II, CPBS, 1919 Rte de Mende, Montpellier, France, LMM, NIAID, NIH Bethesda, MD, USA and Laboratory of Experimental Virology, Department of Medical Microbiology (CINIMA), Amsterdam, The Netherlands
| | - L. Houzet
- UMR5236 CNRS, UMI&II, CPBS, 1919 Rte de Mende, Montpellier, France, LMM, NIAID, NIH Bethesda, MD, USA and Laboratory of Experimental Virology, Department of Medical Microbiology (CINIMA), Amsterdam, The Netherlands
| | - C. Chamontin
- UMR5236 CNRS, UMI&II, CPBS, 1919 Rte de Mende, Montpellier, France, LMM, NIAID, NIH Bethesda, MD, USA and Laboratory of Experimental Virology, Department of Medical Microbiology (CINIMA), Amsterdam, The Netherlands
| | - B. Berkhout
- UMR5236 CNRS, UMI&II, CPBS, 1919 Rte de Mende, Montpellier, France, LMM, NIAID, NIH Bethesda, MD, USA and Laboratory of Experimental Virology, Department of Medical Microbiology (CINIMA), Amsterdam, The Netherlands
| | - M. Mougel
- UMR5236 CNRS, UMI&II, CPBS, 1919 Rte de Mende, Montpellier, France, LMM, NIAID, NIH Bethesda, MD, USA and Laboratory of Experimental Virology, Department of Medical Microbiology (CINIMA), Amsterdam, The Netherlands
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Abstract
Successful live attenuated vaccines mimic natural exposure to pathogens without causing disease and have been successful against several viruses. However, safety concerns prevent the development of attenuated human immunodeficiency virus (HIV) as a vaccine candidate. If a safe, replicating virus vaccine could be developed, it might have the potential to offer significant protection against HIV infection and disease. Described here is the development of a novel self-replicating chimeric virus vaccine candidate that is designed to provide natural exposure to a lentivirus-like particle and to incorporate the properties of a live attenuated virus vaccine without the inherent safety issues associated with attenuated lentiviruses. The genome from the alphavirus Venezuelan equine encephalitis virus (VEE) was modified to express SHIV89.6P genes encoding the structural proteins Gag and Env. Expression of Gag and Env from VEE RNA in primate cells led to the assembly of particles that morphologically and functionally resembled lentivirus virions and that incorporated alphavirus RNA. Infection of CD4⁺ cells with chimeric lentivirus-like particles was specific and productive, resulting in RNA replication, expression of Gag and Env, and generation of progeny chimeric particles. Further genome modifications designed to enhance encapsidation of the chimeric virus genome and to express an attenuated simian immunodeficiency virus (SIV) protease for particle maturation improved the ability of chimeric lentivirus-like particles to propagate in cell culture. This study provides proof of concept for the feasibility of creating chimeric virus genomes that express lentivirus structural proteins and assemble into infectious particles for presentation of lentivirus immunogens in their native and functional conformation.
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43
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Flexible nature and specific functions of the HIV-1 nucleocapsid protein. J Mol Biol 2011; 410:565-81. [PMID: 21762801 DOI: 10.1016/j.jmb.2011.03.037] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 03/14/2011] [Accepted: 03/17/2011] [Indexed: 01/04/2023]
Abstract
One salient feature of reverse transcription in retroviruses, notably in the human immunodeficiency virus type 1, is that it requires the homologous nucleocapsid (NC) protein acting as a chaperoning partner of the genomic RNA template and the reverse transcriptase, from the initiation to the completion of viral DNA synthesis. This short review on the NC protein of human immunodeficiency virus type 1 aims at briefly presenting the flexible nature of NC protein, how it interacts with nucleic acids via its invariant zinc fingers and flanking basic residues, and the possible mechanisms that account for its multiple functions in the early steps of virus replication, notably in the obligatory strand transfer reactions during viral DNA synthesis by the reverse transcriptase enzyme.
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44
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Grigorov B, Bocquin A, Gabus C, Avilov S, Mély Y, Agopian A, Divita G, Gottikh M, Witvrouw M, Darlix JL. Identification of a methylated oligoribonucleotide as a potent inhibitor of HIV-1 reverse transcription complex. Nucleic Acids Res 2011; 39:5586-96. [PMID: 21447560 PMCID: PMC3141241 DOI: 10.1093/nar/gkr117] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Upon HIV-1 infection of a target cell, the viral reverse transcriptase (RT) copies the genomic RNA to synthesize the viral DNA. The genomic RNA is within the incoming HIV-1 core where it is coated by molecules of nucleocapsid (NC) protein that chaperones the reverse transcription process. Indeed, the RT chaperoning properties of NC extend from the initiation of cDNA synthesis to completion of the viral DNA. New and effective drugs against HIV-1 continue to be required, which prompted us to search for compounds aimed at inhibiting NC protein. Here, we report that the NC chaperoning activity is extensively inhibited in vitro by small methylated oligoribonucleotides (mODN). These mODNs were delivered intracellularly using a cell-penetrating-peptide and found to impede HIV-1 replication in primary human cells at nanomolar concentrations. Extensive analysis showed that viral cDNA synthesis was severely impaired by mODNs. Partially resistant viruses with mutations in NC and RT emerged after months of passaging in cell culture. A HIV-1 molecular clone (NL4.3) bearing these mutations was found to replicate at high concentrations of mODN, albeit with a reduced fitness. Small, methylated ODNs such as mODN-11 appear to be a new type of highly potent inhibitor of HIV-1.
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Affiliation(s)
- Boyan Grigorov
- Laboretro, INSERM #758, ENS Lyon, 46 allée d'Italie, 69364 Lyon, Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasboug, Illkirch, France
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45
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Levin JG, Mitra M, Mascarenhas A, Musier-Forsyth K. Role of HIV-1 nucleocapsid protein in HIV-1 reverse transcription. RNA Biol 2010; 7:754-74. [PMID: 21160280 DOI: 10.4161/rna.7.6.14115] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The HIV-1 nucleocapsid protein (NC) is a nucleic acid chaperone, which remodels nucleic acid structures so that the most thermodynamically stable conformations are formed. This activity is essential for virus replication and has a critical role in mediating highly specific and efficient reverse transcription. NC's function in this process depends upon three properties: (1) ability to aggregate nucleic acids; (2) moderate duplex destabilization activity; and (3) rapid on-off binding kinetics. Here, we present a detailed molecular analysis of the individual events that occur during viral DNA synthesis and show how NC's properties are important for almost every step in the pathway. Finally, we also review biological aspects of reverse transcription during infection and the interplay between NC, reverse transcriptase, and human APOBEC3G, an HIV-1 restriction factor that inhibits reverse transcription and virus replication in the absence of the HIV-1 Vif protein.
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Affiliation(s)
- Judith G Levin
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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46
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Abstract
Long terminal repeat (LTR) retrotransposons are not only the ancient predecessors of retroviruses, but they constitute significant fractions of the genomes of many eukaryotic species. Studies of their structure and function are motivated by opportunities to gain insight into common functions of retroviruses and retrotransposons, diverse mechanisms of intracellular genomic mobility, and host factors that diminish or enhance retrotransposition. This review focuses on the nucleocapsid (NC) protein of a Saccharomyces cerevisiae LTR retrotransposon, the metavirus, Ty3. Retrovirus NC promotes genomic (g)RNA dimerization and packaging, tRNA primer annealing, reverse transcription strand transfers, and host protein interactions with gRNA. Studies of Ty3 NC have revealed key roles for Ty3 NC in formation of retroelement assembly sites (retrosomes), and in chaperoning primer tRNA to both dimerize and circularize Ty3 gRNA. We speculate that Ty3 NC, together with P-body and stress-granule proteins, plays a role in transitioning Ty3 RNA from translation template to gRNA, and that interactions between the acidic spacer domain of Ty3 Gag3 and the adjacent basic NC domain control condensation of the virus-like particle.
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Affiliation(s)
- Suzanne B Sandmeyer
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA USA.
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47
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Muriaux D, Darlix JL. Properties and functions of the nucleocapsid protein in virus assembly. RNA Biol 2010; 7:744-53. [PMID: 21157181 DOI: 10.4161/rna.7.6.14065] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
HIV-1 nucleocapsid protein (NC) is a small basic protein generated by the cleavage of the Gag structural polyprotein precusor by the viral protease during virus assembly in the infected cell. HIV-1 NC possesses two copies of a highly conserved CCHC zinc finger (ZnF), flanked by basic residues. HIV-1 NC and more generally retroviral NC proteins are nucleic acid binding proteins possessing potent nucleic acid condensing and chaperoning activities. As such NC protein drives critical structural rearrangements of the genomic RNA, notably RNA dimerization in the course of virus assembly and viral nucleic acid annealing required for genomic RNA replication by the viral reverse transcriptase (RT). Here we review the relationships between the 3D structure of HIV-1 NC, notably the central globular domain encompassing the two zinc fingers and the basic linker and NC functions in the early and late phases of virus replication. One of the salient feature of the NC central globular domain is an hydrophobic plateau which appears to orchestrate the NC functions, such as chaperoning the conversion of the genomic RNA into viral DNA by RT during the early phase, and driving the selection and dimerization of the genomic RNA at the initial stage of viral particle assembly. This ensures a bona fide trafficking of early GagNC-genomic RNA complexes to the plasma membrane of the infected cell and ultimately virion formation and budding.
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Keene SE, King SR, Telesnitsky A. 7SL RNA is retained in HIV-1 minimal virus-like particles as an S-domain fragment. J Virol 2010; 84:9070-7. [PMID: 20610725 PMCID: PMC2937644 DOI: 10.1128/jvi.00714-10] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Accepted: 06/27/2010] [Indexed: 12/19/2022] Open
Abstract
HIV-1 is known to package several small cellular RNAs in addition to its genome. Previous work consistently demonstrated that the host structural RNA 7SL is abundant in HIV-1 virions but has yielded conflicting results regarding whether 7SL is present in minimal, assembly-competent virus-like particles (VLPs). Here, we demonstrate that minimal HIV-1 VLPs retain 7SL RNA primarily as an endoribonucleolytic fragment, referred to as 7SL remnant (7SLrem). Nuclease mapping showed that 7SLrem is a 111-nucleotide internal portion of 7SL, with 5' and 3' ends corresponding to unpaired loops in the 7SL two-dimensional structure. Analysis of VLPs comprised of different subsets of Gag domains revealed that all NC-positive VLPs contained intact 7SL while the presence of 7SLrem correlated with the absence of the NC domain. Because 7SLrem, which maps to the 7SL S domain, was not detectable in infected cells, we propose a model whereby the species recruited to assembling VLPs is intact 7SL RNA, with 7SLrem produced by an endoribonuclease in the absence of NC. Since recruitment of 7SL RNA was a conserved feature of all tested minimal VLPs, our model further suggests that 7SL's recruitment is mediated, either directly or indirectly, through interactions with conserved features of all tested VLPs, such as the C-terminal domain of CA.
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Affiliation(s)
- Sarra E Keene
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Mougel M, Cimarelli A, Darlix JL. Implications of the nucleocapsid and the microenvironment in retroviral reverse transcription. Viruses 2010; 2:939-960. [PMID: 21994662 PMCID: PMC3185662 DOI: 10.3390/v2040939] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 03/03/2010] [Accepted: 04/01/2010] [Indexed: 01/21/2023] Open
Abstract
This mini-review summarizes the process of reverse-transcription, an obligatory step in retrovirus replication during which the retroviral RNA/DNA-dependent DNA polymerase (RT) copies the single-stranded genomic RNA to generate the double-stranded viral DNA while degrading the genomic RNA via its associated RNase H activity. The hybridization of complementary viral sequences by the nucleocapsid protein (NC) receives a special focus, since it acts to chaperone the strand transfers obligatory for synthesis of the complete viral DNA and flanking long terminal repeats (LTR). Since the physiological microenvironment can impact on reverse-transcription, this mini-review also focuses on factors present in the intra-cellular or extra-cellular milieu that can drastically influence both the timing and the activity of reverse-transcription and hence virus infectivity.
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Affiliation(s)
- Marylène Mougel
- CPBS, UMR5236 CNRS, UMI, 4 bd Henri IV, 34965 Montpellier, France; E-Mail:
| | - Andrea Cimarelli
- LaboRetro Unité de Virologie humaine INSERM #758, IFR128, ENS Lyon, 46 Allée d’Italie, 69364 Lyon, France; E-Mail:
| | - Jean-Luc Darlix
- LaboRetro Unité de Virologie humaine INSERM #758, IFR128, ENS Lyon, 46 Allée d’Italie, 69364 Lyon, France; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +33 472728169; Fax: +33 472728137
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Goldschmidt V, Miller Jenkins LM, de Rocquigny H, Darlix JL, Mély Y. The nucleocapsid protein of HIV-1 as a promising therapeutic target for antiviral drugs. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/hiv.10.3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The nucleocapsid protein (NCp7) is a major HIV-1 structural protein that plays key roles in viral replication, mainly through its conserved zinc fingers that direct specific interactions with the viral nucleic acids. Owing to its high degree of conservation and critical functions, NCp7 represents a target of choice for drugs that can potentially complement HAART, thus possibly impairing the circulation of drug-resistant HIV-1 strains. Zinc ejectors showing potent antiretroviral activity were developed, but early generations suffered from limited selectively and significant toxicity. Compounds with improved selectivity have been developed and are being explored as topical microbicide candidates. Several classes of molecules inhibiting the interaction of NCp7 with the viral nucleic acids have also been developed. Although small molecules would be more suited for drug development, most molecules selected by screening showed limited antiretroviral activity. Peptides and RNA aptamers appear to be more promising, but the mechanism of their antiretroviral activity remains elusive. Substantial and more concerted efforts are needed to further develop anti-HIV drugs targeting NCp7 and bring them to the clinic.
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Affiliation(s)
- Valérie Goldschmidt
- Laboratoire de Biophotonique et Pharmacologie, UMR-CNRS 7213, Faculté de Pharmacie, Université de Strasbourg, 74 route du Rhin, 67401 Illkirch-Cedex, France
| | - Lisa M Miller Jenkins
- Laboratory of Cell Biology, NCI, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hugues de Rocquigny
- Laboratoire de Biophotonique et Pharmacologie, UMR-CNRS 7213, Faculté de Pharmacie, Université de Strasbourg, 74 route du Rhin, 67401 Illkirch-Cedex, France
| | - Jean-Luc Darlix
- LaboRetro, Unité de Virologie Humaine INSERM 758, Ecole Normale Supérieure de Lyon, 46 allée d’Italie, 69364 Lyon, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, UMR-CNRS 7213, Faculté de Pharmacie, Université de Strasbourg, 74 route du Rhin, 67401 Illkirch-Cedex, France
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