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Tipo J, Gottipati K, Slaton M, Gonzalez-Gutierrez G, Choi KH. Structure of HIV-1 RRE stem-loop II identifies two conformational states of the high-affinity Rev binding site. Nat Commun 2024; 15:4198. [PMID: 38760344 PMCID: PMC11101469 DOI: 10.1038/s41467-024-48162-y] [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: 11/17/2023] [Accepted: 04/22/2024] [Indexed: 05/19/2024] Open
Abstract
During HIV infection, specific RNA-protein interaction between the Rev response element (RRE) and viral Rev protein is required for nuclear export of intron-containing viral mRNA transcripts. Rev initially binds the high-affinity site in stem-loop II, which promotes oligomerization of additional Rev proteins on RRE. Here, we present the crystal structure of RRE stem-loop II in distinct closed and open conformations. The high-affinity Rev-binding site is located within the three-way junction rather than the predicted stem IIB. The closed and open conformers differ in their non-canonical interactions within the three-way junction, and only the open conformation has the widened major groove conducive to initial Rev interaction. Rev binding assays show that RRE stem-loop II has high- and low-affinity binding sites, each of which binds a Rev dimer. We propose a binding model, wherein Rev-binding sites on RRE are sequentially created through structural rearrangements induced by Rev-RRE interactions.
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Affiliation(s)
- Jerricho Tipo
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX, 77555, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Keerthi Gottipati
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Michael Slaton
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, 47405, USA
| | | | - Kyung H Choi
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, TX, 77555, USA.
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, 47405, USA.
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology, The University of Texas Medical Branch, Galveston, TX, 77555, USA.
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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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3
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Behrens RT, Sherer NM. Retroviral hijacking of host transport pathways for genome nuclear export. mBio 2023; 14:e0007023. [PMID: 37909783 PMCID: PMC10746203 DOI: 10.1128/mbio.00070-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Recent advances in the study of virus-cell interactions have improved our understanding of how viruses that replicate their genomes in the nucleus (e.g., retroviruses, hepadnaviruses, herpesviruses, and a subset of RNA viruses) hijack cellular pathways to export these genomes to the cytoplasm where they access virion egress pathways. These findings shed light on novel aspects of viral life cycles relevant to the development of new antiviral strategies and can yield new tractable, virus-based tools for exposing additional secrets of the cell. The goal of this review is to summarize defined and emerging modes of virus-host interactions that drive the transit of viral genomes out of the nucleus across the nuclear envelope barrier, with an emphasis on retroviruses that are most extensively studied. In this context, we prioritize discussion of recent progress in understanding the trafficking and function of the human immunodeficiency virus type 1 Rev protein, exemplifying a relatively refined example of stepwise, cooperativity-driven viral subversion of multi-subunit host transport receptor complexes.
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Affiliation(s)
- Ryan T. Behrens
- Department of Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Nathan M. Sherer
- McArdle Laboratory for Cancer Research and Carbone Cancer Center, University of Wisconsin, Madison, Wisconsin, USA
- Institute for Molecular Virology, University of Wisconsin, Madison, Wisconsin, USA
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4
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Chaudhary P, Proulx J, Park IW. Ubiquitin-protein ligase E3A (UBE3A) mediation of viral infection and human diseases. Virus Res 2023; 335:199191. [PMID: 37541588 PMCID: PMC10430597 DOI: 10.1016/j.virusres.2023.199191] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/06/2023]
Abstract
The Ubiquitin-protein ligase E3A, UBE3A, also known as E6-associated protein (E6-AP), is known to play an essential role in regulating the degradation of various proteins by transferring Ub from E2 Ub conjugating enzymes to the substrate proteins. Several studies indicate that UBE3A regulates the stabilities of key viral proteins in the virus-infected cells and, thereby, the infected virus-mediated diseases, even if it were reported that UBE3A participates in non-viral-related human diseases. Furthermore, mutations such as deletions and duplications in the maternally inherited gene in the brain cause human neurodevelopmental disorders such as Angelman syndrome (AS) and autism. It is also known that UBE3A functions as a transcriptional coactivator for the expression of steroid hormone receptors. These reports establish that UBE3A is distinguished by its multitudinous functions that are paramount to viral pathology and human diseases. This review is focused on molecular mechanisms for such intensive participation of UBE3A in disease formation and virus regulation.
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Affiliation(s)
- Pankaj Chaudhary
- Department of Microbiology, Immunology and Genetics, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States.
| | - Jessica Proulx
- Department of Microbiology, Immunology and Genetics, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - In-Woo Park
- Department of Microbiology, Immunology and Genetics, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States.
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5
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Jackson PEH, Holsey J, Turse L, Hammarskjold ML, Rekosh D. Rev-Rev Response Element Activity Selection Bias at the Human Immunodeficiency Virus Transmission Bottleneck. Open Forum Infect Dis 2023; 10:ofad486. [PMID: 37854107 PMCID: PMC10580148 DOI: 10.1093/ofid/ofad486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/27/2023] [Indexed: 10/20/2023] Open
Abstract
Background Sexual transmission of human immunodeficiency virus (HIV) is inefficient and results in selection of viral variants based on incompletely understood factors. Functional variation in the Rev-Rev response element (RRE) regulatory axis of HIV affect replication kinetics and relative expression of viral proteins. We explored whether differences in this axis among viral isolates affect transmission fitness. Methods HIV sequences were identified from nine female-to-male transmission pairs. Using a rapid flow cytometric assay, we analyzed Rev-RRE functional activity of primary isolates. Results Rev-RRE activity was significantly lower in recipient viruses compared with corresponding donor viruses. In most transmission events, recipient virus Rev-RRE activity clustered at the extreme low end of the range of donor virus activity. Conclusions These data indicate selection pressure on the Rev-RRE axis during female-to-male sexual transmission. Variation in Rev-RRE activity may permit viral adaptation to different fitness landscapes and could play an important role in HIV pathogenesis.
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Affiliation(s)
- Patrick E H Jackson
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia, USA
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Jordan Holsey
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Lauren Turse
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Marie-Louise Hammarskjold
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - David Rekosh
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
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Jackson PEH, Holsey J, Turse L, Marie-Louise H, Rekosh D. Rev-Rev Response Element Activity Selection Bias at the HIV Transmission Bottleneck. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.05.535732. [PMID: 37066242 PMCID: PMC10104022 DOI: 10.1101/2023.04.05.535732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
HIV is not efficiently transmitted between hosts, and selection of viral variants occurs during the process of sexual transmission. The factors that confer selective advantage at the transmission bottleneck remain incompletely understood. We explored whether differences in the Rev-Rev Response Element (RRE) regulatory axis of HIV affect transmission fitness, since functional variation in the Rev-RRE axis in different viral isolates has been shown to affect replication kinetics and relative expression of many HIV proteins. Single genome HIV sequences were identified from nine linked subject pairs near the time of female-to-male transmission. Using a rapid flow-cytometric assay, we found that the functional Rev-RRE activity varied significantly between isolates. Moreover, it was generally lower in recipients' viruses compared to the corresponding donor viruses. In six of nine transmission events, recipient virus Rev-RRE activity clustered at the extreme low end of the range of donor virus activity. Rev-RRE pair activity was an unpredictable product of component Rev and RRE activity variation. These data indicate selection pressure on the Rev-RRE axis during female-to-male sexual transmission. Variation in the activity of the Rev-RRE axis may permit viral adaptation to different fitness landscapes and could play an important role in HIV pathogenesis.
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Affiliation(s)
- Patrick E. H. Jackson
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia, USA
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Jordan Holsey
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Lauren Turse
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
| | - Hammarskjold Marie-Louise
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
| | - David Rekosh
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, USA
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA
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7
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Sun L, Mailliot J, Schaffitzel C. Nonsense-Mediated mRNA Decay Factor Functions in Human Health and Disease. Biomedicines 2023; 11:722. [PMID: 36979701 PMCID: PMC10045457 DOI: 10.3390/biomedicines11030722] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/06/2023] Open
Abstract
Nonsense-mediated mRNA decay (NMD) is a cellular surveillance mechanism that degrades mRNAs with a premature stop codon, avoiding the synthesis of C-terminally truncated proteins. In addition to faulty mRNAs, NMD recognises ~10% of endogenous transcripts in human cells and downregulates their expression. The up-frameshift proteins are core NMD factors and are conserved from yeast to human in structure and function. In mammals, NMD diversified into different pathways that target different mRNAs employing additional NMD factors. Here, we review our current understanding of molecular mechanisms and cellular roles of NMD pathways and the involvement of more specialised NMD factors. We describe the consequences of mutations in NMD factors leading to neurodevelopmental diseases, and the role of NMD in cancer. We highlight strategies of RNA viruses to evade recognition and decay by the NMD machinery.
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Affiliation(s)
- Lingling Sun
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Justine Mailliot
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Christiane Schaffitzel
- School of Biochemistry, University of Bristol, University Walk, Bristol BS8 1TD, UK
- Bristol Engineering Biology Centre BrisEngBio, 24 Tyndall Ave, Bristol BS8 1TQ, UK
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Identification of a Novel Post-transcriptional Transactivator from the Equine Infectious Anemia Virus. J Virol 2022; 96:e0121022. [PMID: 36448796 PMCID: PMC9769392 DOI: 10.1128/jvi.01210-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
All lentiviruses encode a post-transcriptional transactivator, Rev, which mediates the export of viral mRNA from the nucleus to the cytoplasm and which is required for viral gene expression and viral replication. In the current study, we demonstrate that equine infectious anemia virus (EIAV), an equine lentivirus, encodes a second post-transcriptional transactivator that we designate Grev. Grev is encoded by a novel transcript with a single splicing event that was identified using reverse transcription-PCR (RT-PCR) and RNA-seq in EIAV-infected horse tissues and cells. Grev is about 18 kDa in size, comprises the first 18 amino acids (aa) of Gag protein together with the last 82 aa of Rev, and was detected in EIAV-infected cells. Similar to Rev, Grev is localized to the nucleus, and both are able to mediate the expression of Mat (a recently identified viral protein of unknown function from EIAV), but Rev can mediate the expression of EIAV Gag/Pol, while Grev cannot. We also demonstrate that Grev, similar to Rev, specifically binds to rev-responsive element 2 (RRE-2, located in the first exon of mat mRNAs) to promote nuclear export of mat mRNA via the chromosome region maintenance 1 (CRM1) pathway. However, unlike Rev, whose function depends on its multimerization, we could not detect multimerization of Grev using coimmunoprecipitation (co-IP) or bimolecular fluorescence complementation (BiFC) assays. Together, these data suggest that EIAV encodes two post-transcriptional transactivators, Rev and Grev, with similar, but not identical, functions. IMPORTANCE Nuclear export of viral transcripts is a crucial step for viral gene expression and viral replication in lentiviruses, and this export is regulated by a post-transcriptional transactivator, Rev, that is shared by all lentiviruses. Here, we report that the equine infectious anemia virus (EIAV) encodes a novel viral protein, Grev, and demonstrated that Grev, like Rev, mediates the expression of the viral protein Mat by binding to the first exon of mat mRNAs via the chromosome region maintenance 1 (CRM1) pathway. Grev is encoded by a single-spliced transcript containing two exons, whereas Rev is encoded by a multiple-spliced transcript containing four exons. Moreover, Rev is able to mediate EIAV Gag/Pol expression by binding to rev-responsive element (RRE) located within the Env-coding region, while Grev cannot. Therefore, the present study demonstrates that EIAV encodes two post-transcriptional regulators, Grev and Rev, suggesting that post-transcriptional regulation patterns in lentivirus are diverse and complex.
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Shi Y, Han J, Zhu B, Liu Z, Liang Q, Lan C, Li Z, Li H, Liu Y, Jia L, Li T, Wang X, Li J, Zhang B, Jiang J, Li L. Limited nucleotide changes of HIV-1 subtype B Rev response element in China affect overall Rev-RRE activity and viral replication. Front Microbiol 2022; 13:1044676. [PMID: 36578566 PMCID: PMC9791959 DOI: 10.3389/fmicb.2022.1044676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/11/2022] [Indexed: 12/14/2022] Open
Abstract
The HIV-1 Rev response element (RRE) is a cis-acting RNA element that facilitates the nuclear export of mRNA-containing introns by binding specifically to the Rev protein, enabling a critical step in the viral replication cycle. This study aims to determine the subtype-specific loci of HIV-1 subtype B RRE circulating in China and to analyze their effects on Rev-RRE function and HIV-1 replication. We amplified 71 HIV-1 subtype B RRE full-length sequences from the HIV patients' blood samples collected in China, analyzed the subtype-specific loci on them by comparing them with subtype B in the United States, and predicted their RNA secondary structures. Rev-RRE activity assay was used to test the binding activity of Rev and different RREs. Infectious clones were mutated to test the effect of the subtype-specific loci on replication capacity. In this study, two sites were determined to be the subtype-specific loci of HIV-1 subtype B RRE circulating in China. Both site 186 and site 56-57insAAC can significantly increase the viral mRNA transcription and Rev-RRE activity, but only the site 186 can significantly improve viral replication ability. Collectively, the subtype-specific loci of subtype B RRE circulating in China have a significant effect on the Rev-RRE activity and viral replication. This study investigates the subtype-specific loci of RRE, which are unique to retroviruses and essential for viral replication, and will help to explore the reasons why subtype B circulating in China is more widespread and persistent than American subtype B in China at the genetic level, and will provide theoretical support for the development of more inclusive detection and treatment methods for subtype B circulating in China. At the same time, it will also provide insight into the impact of different subtype HIV-1 genetic characteristics on viral replication.
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Affiliation(s)
- Yuting Shi
- Guangxi Key Laboratory of AIDS Prevention and Treatment, School of Public Health, Guangxi Medical University, Nanning, China,Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jingwan Han
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Bo Zhu
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhi Liu
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Qingmiao Liang
- School of Graduate Studies, Guangxi Medical University, Nanning, China
| | - Chunlin Lan
- Guangxi Key Laboratory of AIDS Prevention and Treatment, School of Public Health, Guangxi Medical University, Nanning, China,Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhengyang Li
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Hanping Li
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Yongjian Liu
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Lei Jia
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Tianyi Li
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Xiaolin Wang
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jingyun Li
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Bohan Zhang
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Junjun Jiang
- Guangxi Key Laboratory of AIDS Prevention and Treatment, School of Public Health, Guangxi Medical University, Nanning, China,Junjun Jiang,
| | - Lin Li
- Department of AIDS Research, State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China,*Correspondence: Lin Li,
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Dzhivhuho G, Holsey J, Honeycutt E, O'Farrell H, Rekosh D, Hammarskjold ML, Jackson PEH. HIV-1 Rev-RRE functional activity in primary isolates is highly dependent on minimal context-dependent changes in Rev. Sci Rep 2022; 12:18416. [PMID: 36319640 PMCID: PMC9626594 DOI: 10.1038/s41598-022-21714-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/30/2022] [Indexed: 01/01/2023] Open
Abstract
During HIV infection, intron-containing viral mRNAs are exported from the cell nucleus to the cytoplasm to complete the replication cycle. Cellular restrictions on the export of incompletely spliced transcripts are overcome by a viral protein, Rev, and an RNA structure found in all unspliced and incompletely spliced viral mRNAs, the Rev Response Element (RRE). Primary HIV isolates display substantial variation in the sequence and functional activity of Rev proteins. We analyzed Rev from two primary isolates with disparate activity that resulted in differences in in vitro fitness of replication-competent viral constructs. The results showed that amino acid differences within the oligomerization domain, but not the arginine-rich motif or the nuclear export signal, determined the level of Rev activity. Two specific amino acid substitutions were sufficient to alter the low-activity Rev to a high-activity phenotype. Other mutations in Rev sequences had unpredictable effects on activity that differed between the two Rev backbones. The sensitivity of Rev function level to small sequence changes likely permits modulation of Rev-RRE activity during HIV infection, which may play a role in pathogenesis. The functional consequences of Rev mutations differed between primary isolates, highlighting the challenge of generalizing studies of Rev conducted using laboratory HIV strains.
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Affiliation(s)
- Godfrey Dzhivhuho
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Jordan Holsey
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Ethan Honeycutt
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Heather O'Farrell
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - David Rekosh
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Marie-Louise Hammarskjold
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, VA, USA
- Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Patrick E H Jackson
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, VA, USA.
- Division of Infectious Diseases and International Health, School of Medicine, University of Virginia, Charlottesville, VA, USA.
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Hansen T, Baris J, Zhao M, Sutton RE. Cell-based and cell-free firefly luciferase complementation assay to quantify Human Immunodeficiency Virus type 1 Rev-Rev interaction. Virology 2022; 576:30-41. [DOI: 10.1016/j.virol.2022.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 08/17/2022] [Accepted: 08/20/2022] [Indexed: 11/17/2022]
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12
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Hanson HM, Willkomm NA, Yang H, Mansky LM. Human Retrovirus Genomic RNA Packaging. Viruses 2022; 14:1094. [PMID: 35632835 PMCID: PMC9142903 DOI: 10.3390/v14051094] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/12/2022] [Accepted: 05/14/2022] [Indexed: 02/07/2023] Open
Abstract
Two non-covalently linked copies of the retrovirus genome are specifically recruited to the site of virus particle assembly and packaged into released particles. Retroviral RNA packaging requires RNA export of the unspliced genomic RNA from the nucleus, translocation of the genome to virus assembly sites, and specific interaction with Gag, the main viral structural protein. While some aspects of the RNA packaging process are understood, many others remain poorly understood. In this review, we provide an update on recent advancements in understanding the mechanism of RNA packaging for retroviruses that cause disease in humans, i.e., HIV-1, HIV-2, and HTLV-1, as well as advances in the understanding of the details of genomic RNA nuclear export, genome translocation to virus assembly sites, and genomic RNA dimerization.
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Affiliation(s)
- Heather M. Hanson
- Molecular, Cellular, Developmental Biology, and Genetics Graduate Program, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA;
- Institute for Molecular Virology, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA; (N.A.W.); (H.Y.)
| | - Nora A. Willkomm
- Institute for Molecular Virology, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA; (N.A.W.); (H.Y.)
- DDS-PhD Dual Degree Program, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
| | - Huixin Yang
- Institute for Molecular Virology, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA; (N.A.W.); (H.Y.)
- Comparative Molecular Biosciences Graduate Program, University of Minnesota—Twin Cities, St. Paul, MN 55455, USA
| | - Louis M. Mansky
- Molecular, Cellular, Developmental Biology, and Genetics Graduate Program, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA;
- Institute for Molecular Virology, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA; (N.A.W.); (H.Y.)
- DDS-PhD Dual Degree Program, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Comparative Molecular Biosciences Graduate Program, University of Minnesota—Twin Cities, St. Paul, MN 55455, USA
- Masonic Cancer Center, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
- Division of Basic Sciences, School of Dentistry, University of Minnesota—Twin Cities, Minneapolis, MN 55455, USA
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Abstract
Being able to effectively target RNA with potent ligands will open up a large number of potential therapeutic options. The knowledge on how to achieve this is ever expanding but an important question that remains open is what chemical matter is suitable to achieve this goal. The high flexibility of an RNA as well as its more limited chemical diversity and featureless binding sites can be difficult to target selectively but can be addressed by well-designed cyclic peptides. In this review we will provide an overview of reported cyclic peptide ligands for therapeutically relevant RNA targets and discuss the methods used to discover them. We will also provide critical insights into the properties required for potent and selective interaction and suggestions on how to assess these parameters. The use of cyclic peptides to target RNA is still in its infancy but the lessons learned from past examples can be adopted for the development of novel potent and selective ligands.
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Affiliation(s)
- Sunit Pal
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Peter 't Hart
- Chemical Genomics Centre of the Max Planck Society, Max Planck Institute of Molecular Physiology, Dortmund, Germany
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14
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Evans EL, Pocock GM, Einsdorf G, Behrens RT, Dobson ETA, Wiedenmann M, Birkhold C, Ahlquist P, Eliceiri KW, Sherer NM. HIV RGB: Automated Single-Cell Analysis of HIV-1 Rev-Dependent RNA Nuclear Export and Translation Using Image Processing in KNIME. Viruses 2022; 14:903. [PMID: 35632645 PMCID: PMC9145009 DOI: 10.3390/v14050903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/21/2022] [Accepted: 04/23/2022] [Indexed: 01/27/2023] Open
Abstract
Single-cell imaging has emerged as a powerful means to study viral replication dynamics and identify sites of virus−host interactions. Multivariate aspects of viral replication cycles yield challenges inherent to handling large, complex imaging datasets. Herein, we describe the design and implementation of an automated, imaging-based strategy, “Human Immunodeficiency Virus Red-Green-Blue” (HIV RGB), for deriving comprehensive single-cell measurements of HIV-1 unspliced (US) RNA nuclear export, translation, and bulk changes to viral RNA and protein (HIV-1 Rev and Gag) subcellular distribution over time. Differentially tagged fluorescent viral RNA and protein species are recorded using multicolor long-term (>24 h) time-lapse video microscopy, followed by image processing using a new open-source computational imaging workflow dubbed “Nuclear Ring Segmentation Analysis and Tracking” (NR-SAT) based on ImageJ plugins that have been integrated into the Konstanz Information Miner (KNIME) analytics platform. We describe a typical HIV RGB experimental setup, detail the image acquisition and NR-SAT workflow accompanied by a step-by-step tutorial, and demonstrate a use case wherein we test the effects of perturbing subcellular localization of the Rev protein, which is essential for viral US RNA nuclear export, on the kinetics of HIV-1 late-stage gene regulation. Collectively, HIV RGB represents a powerful platform for single-cell studies of HIV-1 post-transcriptional RNA regulation. Moreover, we discuss how similar NR-SAT-based design principles and open-source tools might be readily adapted to study a broad range of dynamic viral or cellular processes.
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Affiliation(s)
- Edward L. Evans
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Ginger M. Pocock
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Gabriel Einsdorf
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- KNIME GmbH, 78467 Konstanz, Germany;
| | - Ryan T. Behrens
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
| | - Ellen T. A. Dobson
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
| | - Marcel Wiedenmann
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- KNIME GmbH, 78467 Konstanz, Germany;
| | | | - Paul Ahlquist
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
- Morgridge Institute for Research, Madison, WI 53715, USA
- John and Jeanne Rowe Center for Research in Virology, Madison, WI 53715, USA
| | - Kevin W. Eliceiri
- Laboratory for Optical and Computational Instrumentation, Center for Quantitative Cell Imaging, University of Wisconsin-Madison, Madison, WI 53706, USA; (G.E.); (E.T.A.D.); (M.W.)
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Nathan M. Sherer
- McArdle Laboratory for Cancer Research (Department of Oncology), Institute for Molecular Virology, and Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI 53706, USA; (E.L.E.III); (G.M.P.); (R.T.B.)
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15
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Proulx J, Ghaly M, Park IW, Borgmann K. HIV-1-Mediated Acceleration of Oncovirus-Related Non-AIDS-Defining Cancers. Biomedicines 2022; 10:biomedicines10040768. [PMID: 35453518 PMCID: PMC9024568 DOI: 10.3390/biomedicines10040768] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/22/2022] [Accepted: 03/22/2022] [Indexed: 11/25/2022] Open
Abstract
With the advent of combination antiretroviral therapy (cART), overall survival has been improved, and the incidence of acquired immunodeficiency syndrome (AIDS)-defining cancers has also been remarkably reduced. However, non-AIDS-defining cancers among human immunodeficiency virus-1 (HIV-1)-associated malignancies have increased significantly so that cancer is the leading cause of death in people living with HIV in certain highly developed countries, such as France. However, it is currently unknown how HIV-1 infection raises oncogenic virus-mediated cancer risks in the HIV-1 and oncogenic virus co-infected patients, and thus elucidation of the molecular mechanisms for how HIV-1 expedites the oncogenic viruses-triggered tumorigenesis in the co-infected hosts is imperative for developing therapeutics to cure or impede the carcinogenesis. Hence, this review is focused on HIV-1 and oncogenic virus co-infection-mediated molecular processes in the acceleration of non-AIDS-defining cancers.
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16
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Kitao K, Nakagawa S, Miyazawa T. An ancient retroviral RNA element hidden in mammalian genomes and its involvement in co-opted retroviral gene regulation. Retrovirology 2021; 18:36. [PMID: 34753509 PMCID: PMC8579622 DOI: 10.1186/s12977-021-00580-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/22/2021] [Indexed: 01/19/2023] Open
Abstract
Background Retroviruses utilize multiple unique RNA elements to control RNA processing and translation. However, it is unclear what functional RNA elements are present in endogenous retroviruses (ERVs). Gene co-option from ERVs sometimes entails the conservation of viral cis-elements required for gene expression, which might reveal the RNA regulation in ERVs. Results Here, we characterized an RNA element found in ERVs consisting of three specific sequence motifs, called SPRE. The SPRE-like elements were found in different ERV families but not in any exogenous viral sequences examined. We observed more than a thousand of copies of the SPRE-like elements in several mammalian genomes; in human and marmoset genomes, they overlapped with lineage-specific ERVs. SPRE was originally found in human syncytin-1 and syncytin-2. Indeed, several mammalian syncytin genes: mac-syncytin-3 of macaque, syncytin-Ten1 of tenrec, and syncytin-Car1 of Carnivora, contained the SPRE-like elements. A reporter assay revealed that the enhancement of gene expression by SPRE depended on the reporter genes. Mutation of SPRE impaired the wild-type syncytin-2 expression while the same mutation did not affect codon-optimized syncytin-2, suggesting that SPRE activity depends on the coding sequence. Conclusions These results indicate multiple independent invasions of various mammalian genomes by retroviruses harboring SPRE-like elements. Functional SPRE-like elements are found in several syncytin genes derived from these retroviruses. This element may facilitate the expression of viral genes, which were suppressed due to inefficient codon frequency or repressive elements within the coding sequences. These findings provide new insights into the long-term evolution of RNA elements and molecular mechanisms of gene expression in retroviruses. Supplementary Information The online version contains supplementary material available at 10.1186/s12977-021-00580-2.
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Affiliation(s)
- Koichi Kitao
- Laboratory of Virus-Host Coevolution, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto, 606-8507, Japan
| | - So Nakagawa
- Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Kanagawa, 259-1193, Japan
| | - Takayuki Miyazawa
- Laboratory of Virus-Host Coevolution, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto, 606-8507, Japan.
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17
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Jackson PEH, Dzhivhuho G, Rekosh D, Hammarskjold ML. Sequence and Functional Variation in the HIV-1 Rev Regulatory Axis. Curr HIV Res 2021; 18:85-98. [PMID: 31906839 DOI: 10.2174/1570162x18666200106112842] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/22/2019] [Accepted: 12/02/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND To complete its replication cycle, HIV-1 requires the nucleocytoplasmic export of intron-containing viral mRNAs. This process is ordinarily restricted by the cell, but HIV overcomes the block by means of a viral protein, Rev, and an RNA secondary structure found in all unspliced and incompletely spliced viral mRNAs called the Rev Response Element (RRE). In vivo activity of the Rev-RRE axis requires Rev binding to the RRE, oligomerization of Rev to form a competent ribonucleoprotein complex, and recruitment of cellular factors including Crm1 and RanGTP in order to export the targeted transcript. Sequence variability is observed among primary isolates in both Rev and the RRE, and the activity of both can be modulated through relatively small sequence changes. Primary isolates show differences in Rev-RRE activity and a few studies have found a correlation between lower Rev-RRE activity and slower progression of clinical disease. Lower Rev-RRE activity has also been associated with the evasion of cytotoxic T lymphocyte mediated killing. CONCLUSION The HIV-1 Rev-RRE regulatory axis is an understudied mechanism by which viral adaptation to diverse immune milieus may take place. There is evidence that this adaptation plays a role in HIV pathogenesis, particularly in immune evasion and latency, but further studies with larger sample sizes are warranted.
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Affiliation(s)
- Patrick E H Jackson
- Division of Infectious Diseases and International Health, School of Medicine, University of Virginia, Charlottesville, Virginia United States.,Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, United States
| | - Godfrey Dzhivhuho
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, United States.,Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, Virginia, United States
| | - David Rekosh
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, United States.,Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, Virginia, United States
| | - Marie-Louise Hammarskjold
- Myles H. Thaler Center for HIV and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, United States.,Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, Virginia, United States
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18
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Ali N, Khalil R, Nur-E-Alam M, Ahmed S, Ul-Haq Z. Probing the mechanism of peptide binding to REV response element RNA of HIV-1; MD simulations and free energy calculations. J Biomol Struct Dyn 2020; 40:4399-4408. [PMID: 33323039 DOI: 10.1080/07391102.2020.1856722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Ribonucleic acid (RNA) of HIV-1 contains a 350 nucleotide, highly structured, cis-acting element called RRE (REV-response-element RNA), essential for virus replication. REV is a natural peptide that binds to RRE and transports it from the nucleus to cytoplasm where it is expressed into a new virus. The synthetic peptide known as RSG-1.2 also binds the RRE element and competes with REV. The purpose of study is to rationally design novel peptides such as RSG peptide with improved binding affinity to prevent the transport of HIV-1 RNA and so replication of virus. Herein, we performed MD simulation and free energy calculations to evaluate the interactions and binding free energies of REV (PDB ID: 4PMI) and RSGs peptides (PDB IDs: 1G70 and 1I9F) with RRE. The protein-RNA interactions were analyzed using the MM-PBSA method. Results suggest that REV has more binding free energy -188.41 kcal/mol than two RSG peptides with total binding free energy -120.97 and -141.46 kcal/mol. The ARG and ASN were found to be important residues of REV. In the RRE sequence, the nucleotides 62-67 and 78-84 were found to be important contributors in binding free energy. This study play a major role in elaboration of binding REV and RSG1-2 with RRE element and pave the way for further synthesis of peptide that can bind with RRE element and can be selected as therapeutic agent for HIV.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Nizakat Ali
- Dr. Panjwani Center for Molecular Medicine and Drug Research, H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Ruqaiya Khalil
- Dr. Panjwani Center for Molecular Medicine and Drug Research, H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Mohammad Nur-E-Alam
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Sarfaraz Ahmed
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Zaheer Ul-Haq
- Dr. Panjwani Center for Molecular Medicine and Drug Research, H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
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19
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Abstract
The human immunodeficiency virus type 1 (HIV-1) proteome is expressed from alternatively spliced and unspliced genomic RNAs. However, HIV-1 RNAs that are not fully spliced are perceived by the host machinery as defective and are retained in the nucleus. During late infection, HIV-1 bypasses this regulatory mechanism by expression of the Rev protein from a fully spliced mRNA. Once imported into the nucleus, Rev mediates the export of unprocessed HIV-1 RNAs to the cytoplasm, leading to the production of the viral progeny. While regarded as a canonical RNA export factor, Rev has also been linked to HIV-1 RNA translation, stabilization, splicing and packaging. However, Rev's functions beyond RNA export have remained poorly understood. Here, we revisit this paradigmatic protein, reviewing recent data investigating its structure and function. We conclude by asking: what remains unknown about this enigmatic viral protein?
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Affiliation(s)
| | - Aino Järvelin
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Alfredo Castello
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, 464 Bearsden Road, Glasgow G61 1QH, UK
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20
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Gales JP, Kubina J, Geldreich A, Dimitrova M. Strength in Diversity: Nuclear Export of Viral RNAs. Viruses 2020; 12:E1014. [PMID: 32932882 PMCID: PMC7551171 DOI: 10.3390/v12091014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/03/2020] [Accepted: 09/09/2020] [Indexed: 12/11/2022] Open
Abstract
The nuclear export of cellular mRNAs is a complex process that requires the orchestrated participation of many proteins that are recruited during the early steps of mRNA synthesis and processing. This strategy allows the cell to guarantee the conformity of the messengers accessing the cytoplasm and the translation machinery. Most transcripts are exported by the exportin dimer Nuclear RNA export factor 1 (NXF1)-NTF2-related export protein 1 (NXT1) and the transcription-export complex 1 (TREX1). Some mRNAs that do not possess all the common messenger characteristics use either variants of the NXF1-NXT1 pathway or CRM1, a different exportin. Viruses whose mRNAs are synthesized in the nucleus (retroviruses, the vast majority of DNA viruses, and influenza viruses) exploit both these cellular export pathways. Viral mRNAs hijack the cellular export machinery via complex secondary structures recognized by cellular export factors and/or viral adapter proteins. This way, the viral transcripts succeed in escaping the host surveillance system and are efficiently exported for translation, allowing the infectious cycle to proceed. This review gives an overview of the cellular mRNA nuclear export mechanisms and presents detailed insights into the most important strategies that viruses use to export the different forms of their RNAs from the nucleus to the cytoplasm.
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Affiliation(s)
- Jón Pol Gales
- Institut de Biologie Moléculaire des Plantes, The French National Center for Scientific Research (CNRS) UPR2357, Université de Strasbourg, F-67084 Strasbourg, France; (J.P.G.); (J.K.); (A.G.)
| | - Julie Kubina
- Institut de Biologie Moléculaire des Plantes, The French National Center for Scientific Research (CNRS) UPR2357, Université de Strasbourg, F-67084 Strasbourg, France; (J.P.G.); (J.K.); (A.G.)
- SVQV UMR-A 1131, INRAE, Université de Strasbourg, F-68000 Colmar, France
| | - Angèle Geldreich
- Institut de Biologie Moléculaire des Plantes, The French National Center for Scientific Research (CNRS) UPR2357, Université de Strasbourg, F-67084 Strasbourg, France; (J.P.G.); (J.K.); (A.G.)
| | - Maria Dimitrova
- Institut de Biologie Moléculaire des Plantes, The French National Center for Scientific Research (CNRS) UPR2357, Université de Strasbourg, F-67084 Strasbourg, France; (J.P.G.); (J.K.); (A.G.)
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21
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Vicenzi E, Poli G. The interferon-stimulated gene TRIM22: A double-edged sword in HIV-1 infection. Cytokine Growth Factor Rev 2018; 40:40-47. [PMID: 29650252 DOI: 10.1016/j.cytogfr.2018.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 02/07/2018] [Indexed: 12/17/2022]
Abstract
Infection of target cells by the human immunodeficiency virus type-1 (HIV-1) is hampered by constitutively expressed host cell proteins preventing or curtailing virus replication and therefore defined as "restriction factors". Among them, members of the tripartite motif (TRIM) family have emerged as important players endowed with both antiviral effects and modulatory capacity of the innate immune response. TRIM5α and TRIM19 (i.e. promyelocytic leukemia, PML) are among the best-characterized family members; however, in this review we will focus on the potential role of another family member, i.e. TRIM22, a factor strongly induced by interferon stimulation, in HIV infection in vivo and in vitro in the context of its broader antiviral effects. We will also focus on the potential role of TRIM22 in HIV-1-infected individuals speculating on its dual role in controlling virus replication and more complex role in chronic infection. At the molecular levels, we will review the evidence in favor of a relevant role of TRIM22 as epigenetic inhibitor of HIV-1 transcription acting by preventing the binding of the host cell transcription factor Sp1 to the viral promoter. These evidences suggest that TRIM22 should be considered a potential new player in either the establishment or maintenance of HIV-1 reservoirs of latently infected cells unaffected by combination antiretroviral therapy.
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Affiliation(s)
- Elisa Vicenzi
- Viral Pathogens and Biosafety Unit, P2-P3 Laboratories, DIBIT, Via Olgettina n. 58, 20132, Milano, Italy.
| | - Guido Poli
- AIDS Immunopathogenesis Unit, San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, School of Medicine, Milan, Italy
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22
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Yue Y, Coskun AK, Jawanda N, Auer J, Sutton RE. Differential interaction between human and murine Crm1 and lentiviral Rev proteins. Virology 2018; 513:1-10. [PMID: 29028476 PMCID: PMC5914484 DOI: 10.1016/j.virol.2017.09.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 09/30/2017] [Accepted: 09/30/2017] [Indexed: 01/30/2023]
Abstract
Mice have multiple obstacles to HIV replication, including a block of unspliced and partially spliced viral mRNA nuclear export. In human, Rev binds to the Rev-response element and human (h) Crm1, facilitating nuclear export of RRE-containing viral RNAs. Murine (m) Crm1 is less functional than hCrm1 in this regard. Here we demonstrated that in biochemical experiments mCrm1 failed to interact with HIV Rev whereas hCrm1 did. In genetic experiments in human cells, we observed a modest but significant differential effect between mCrm1 and hCrm1, which was also true of other lentiviral Revs tested. Triple mutant hCrm1 P411T-M412V-F414S behaved similarly to mCrm1, whereas mCrm1 with T411P-V412M-S414F regained some activity, although contribution of additional residues to its function can not be excluded. Similar results were observed in murine cells. This suggests a differential interaction between hCrm1 and mCrm1 and many lentiviral Revs, which may partially explain the HIV replicative defect in mice.
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Affiliation(s)
- Yan Yue
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Ayse K Coskun
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Navneet Jawanda
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Jim Auer
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Richard E Sutton
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, United States.
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23
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Umunnakwe CN, Dorman KS, Dobbs D, Carpenter S. Identification of a homogenous structural basis for oligomerization by retroviral Rev-like proteins. Retrovirology 2017; 14:40. [PMID: 28830558 PMCID: PMC5568270 DOI: 10.1186/s12977-017-0366-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 08/11/2017] [Indexed: 11/17/2022] Open
Abstract
Background Rev-like proteins are post-transcriptional regulatory proteins found in several retrovirus genera, including lentiviruses, betaretroviruses, and deltaretroviruses. These essential proteins mediate the nuclear export of incompletely spliced viral RNA, and act by tethering viral pre-mRNA to the host CRM1 nuclear export machinery. Although all Rev-like proteins are functionally homologous, they share less than 30% sequence identity. In the present study, we computationally assessed the extent of structural homology among retroviral Rev-like proteins within a phylogenetic framework. Results We undertook a comprehensive analysis of overall protein domain architecture and predicted secondary structural features for representative members of the Rev-like family of proteins. Similar patterns of α-helical domains were identified for Rev-like proteins within each genus, with the exception of deltaretroviruses, which were devoid of α-helices. Coiled-coil oligomerization motifs were also identified for most Rev-like proteins, with the notable exceptions of HIV-1, the deltaretroviruses, and some small ruminant lentiviruses. In Rev proteins of primate lentiviruses, the presence of predicted coiled-coil motifs segregated within specific primate lineages: HIV-1 descended from SIVs that lacked predicted coiled-coils in Rev whereas HIV-2 descended from SIVs that contained predicted coiled-coils in Rev. Phylogenetic ancestral reconstruction of coiled-coils for all Rev-like proteins predicted a single origin for the coiled-coil motif, followed by three losses of the predicted signal. The absence of a coiled-coil signal in HIV-1 was associated with replacement of canonical polar residues with non-canonical hydrophobic residues. However, hydrophobic residues were retained in the key ‘a’ and ‘d’ positions, and the α-helical region of HIV-1 Rev oligomerization domain could be modeled as a helical wheel with two predicted interaction interfaces. Moreover, the predicted interfaces mapped to the dimerization and oligomerization interfaces in HIV-1 Rev crystal structures. Helical wheel projections of other retroviral Rev-like proteins, including endogenous sequences, revealed similar interaction interfaces that could mediate oligomerization. Conclusions Sequence-based computational analyses of Rev-like proteins, together with helical wheel projections of oligomerization domains, reveal a conserved homogeneous structural basis for oligomerization by retroviral Rev-like proteins. Electronic supplementary material The online version of this article (doi:10.1186/s12977-017-0366-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chijioke N Umunnakwe
- Department of Animal Science, Iowa State University, Ames, IA, 50011, USA.,Program in Bioinformatics and Computational Biology, Iowa State University, Ames, IA, USA.,HIV Dynamics and Replication Program, National Cancer Institute, 1050 Boyles St, Frederick, MD, 21702, USA
| | - Karin S Dorman
- Program in Bioinformatics and Computational Biology, Iowa State University, Ames, IA, USA.,Department of Genetics, Developmental and Cell Biology, Iowa State University, Ames, IA, USA.,Department of Statistics, Iowa State University, Ames, IA, USA
| | - Drena Dobbs
- Program in Bioinformatics and Computational Biology, Iowa State University, Ames, IA, USA.,Department of Genetics, Developmental and Cell Biology, Iowa State University, Ames, IA, USA
| | - Susan Carpenter
- Department of Animal Science, Iowa State University, Ames, IA, 50011, USA.
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24
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Vink CA, Counsell JR, Perocheau DP, Karda R, Buckley SMK, Brugman MH, Galla M, Schambach A, McKay TR, Waddington SN, Howe SJ. Eliminating HIV-1 Packaging Sequences from Lentiviral Vector Proviruses Enhances Safety and Expedites Gene Transfer for Gene Therapy. Mol Ther 2017; 25:1790-1804. [PMID: 28550974 PMCID: PMC5542766 DOI: 10.1016/j.ymthe.2017.04.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 12/30/2022] Open
Abstract
Lentiviral vector genomic RNA requires sequences that partially overlap wild-type HIV-1 gag and env genes for packaging into vector particles. These HIV-1 packaging sequences constitute 19.6% of the wild-type HIV-1 genome and contain functional cis elements that potentially compromise clinical safety. Here, we describe the development of a novel lentiviral vector (LTR1) with a unique genomic structure designed to prevent transfer of HIV-1 packaging sequences to patient cells, thus reducing the total HIV-1 content to just 4.8% of the wild-type genome. This has been achieved by reconfiguring the vector to mediate reverse-transcription with a single strand transfer, instead of the usual two, and in which HIV-1 packaging sequences are not copied. We show that LTR1 vectors offer improved safety in their resistance to remobilization in HIV-1 particles and reduced frequency of splicing into human genes. Following intravenous luciferase vector administration to neonatal mice, LTR1 sustained a higher level of liver transgene expression than an equivalent dose of a standard lentivirus. LTR1 vectors produce reverse-transcription products earlier and start to express transgenes significantly quicker than standard lentiviruses after transduction. Finally, we show that LTR1 is an effective lentiviral gene therapy vector as demonstrated by correction of a mouse hemophilia B model.
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Affiliation(s)
- Conrad A Vink
- Molecular and Cellular Immunology, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - John R Counsell
- Molecular and Cellular Immunology, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK; Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK.
| | - Dany P Perocheau
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
| | - Rajvinder Karda
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
| | - Suzanne M K Buckley
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
| | - Martijn H Brugman
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, 2300 RC Leiden, the Netherlands
| | - Melanie Galla
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Axel Schambach
- Institute of Experimental Hematology, Hannover Medical School, 30625 Hannover, Germany
| | - Tristan R McKay
- School of Healthcare Science, John Dalton Building, Manchester Metropolitan University, Chester Street, Manchester M15 6BH, UK
| | - Simon N Waddington
- Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK; MRC Antiviral Gene Therapy Research Unit, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg 2000, South Africa
| | - Steven J Howe
- Molecular and Cellular Immunology, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK; Gene Transfer Technology Group, Institute for Women's Health, University College London, 86-96 Chenies Mews, London WC1E 6HX, UK
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25
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ADAR1 and PACT contribute to efficient translation of transcripts containing HIV-1 trans-activating response (TAR) element. Biochem J 2017; 474:1241-1257. [PMID: 28167698 PMCID: PMC5363390 DOI: 10.1042/bcj20160964] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/30/2017] [Accepted: 02/06/2017] [Indexed: 12/15/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) has evolved various measures to counter the host cell's innate antiviral response during the course of infection. Interferon (IFN)-stimulated gene products are produced following HIV-1 infection to limit viral replication, but viral proteins and RNAs counteract their effect. One such mechanism is specifically directed against the IFN-induced Protein Kinase PKR, which is centrally important to the cellular antiviral response. In the presence of viral RNAs, PKR is activated and phosphorylates the translation initiation factor eIF2α. This shuts down the synthesis of both host and viral proteins, allowing the cell to mount an effective antiviral response. PACT (protein activator of PKR) is a cellular protein activator of PKR, primarily functioning to activate PKR in response to cellular stress. Recent studies have indicated that during HIV-1 infection, PACT's normal cellular function is compromised and that PACT is unable to activate PKR. Using various reporter systems and in vitro kinase assays, we establish in this report that interactions between PACT, ADAR1 and HIV-1-encoded Tat protein diminish the activation of PKR in response to HIV-1 infection. Our results highlight an important pathway by which HIV-1 transcripts subvert the host cell's antiviral activities to enhance their translation.
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26
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Pocock GM, Zimdars LL, Yuan M, Eliceiri KW, Ahlquist P, Sherer NM. Diverse activities of viral cis-acting RNA regulatory elements revealed using multicolor, long-term, single-cell imaging. Mol Biol Cell 2017; 28:476-487. [PMID: 27903772 PMCID: PMC5341730 DOI: 10.1091/mbc.e16-08-0612] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 02/06/2023] Open
Abstract
Cis-acting RNA structural elements govern crucial aspects of viral gene expression. How these structures and other posttranscriptional signals affect RNA trafficking and translation in the context of single cells is poorly understood. Herein we describe a multicolor, long-term (>24 h) imaging strategy for measuring integrated aspects of viral RNA regulatory control in individual cells. We apply this strategy to demonstrate differential mRNA trafficking behaviors governed by RNA elements derived from three retroviruses (HIV-1, murine leukemia virus, and Mason-Pfizer monkey virus), two hepadnaviruses (hepatitis B virus and woodchuck hepatitis virus), and an intron-retaining transcript encoded by the cellular NXF1 gene. Striking behaviors include "burst" RNA nuclear export dynamics regulated by HIV-1's Rev response element and the viral Rev protein; transient aggregations of RNAs into discrete foci at or near the nuclear membrane triggered by multiple elements; and a novel, pulsiform RNA export activity regulated by the hepadnaviral posttranscriptional regulatory element. We incorporate single-cell tracking and a data-mining algorithm into our approach to obtain RNA element-specific, high-resolution gene expression signatures. Together these imaging assays constitute a tractable, systems-based platform for studying otherwise difficult to access spatiotemporal features of viral and cellular gene regulation.
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MESH Headings
- Active Transport, Cell Nucleus/physiology
- Cell Nucleus/metabolism
- Gene Expression Regulation, Viral
- Gene Products, rev/metabolism
- Genes, env/physiology
- HIV-1
- Mason-Pfizer monkey virus
- Molecular Imaging/methods
- RNA Processing, Post-Transcriptional/physiology
- RNA, Messenger/metabolism
- RNA, Viral
- Regulatory Sequences, Nucleic Acid/genetics
- Regulatory Sequences, Nucleic Acid/physiology
- Regulatory Sequences, Ribonucleic Acid/genetics
- Regulatory Sequences, Ribonucleic Acid/physiology
- Single-Cell Analysis/methods
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Affiliation(s)
- Ginger M Pocock
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI 53706
| | - Laraine L Zimdars
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706
| | - Ming Yuan
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI 53706
- Department of Statistics, University of Wisconsin-Madison, Madison, WI 53706
| | - Kevin W Eliceiri
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI 53706
- Laboratory for Optical and Computational Instrumentation and Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706
| | - Paul Ahlquist
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI 53706
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53706
| | - Nathan M Sherer
- McArdle Laboratory for Cancer Research and Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706
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Nuclear Export Signal Masking Regulates HIV-1 Rev Trafficking and Viral RNA Nuclear Export. J Virol 2017; 91:JVI.02107-16. [PMID: 27852860 DOI: 10.1128/jvi.02107-16] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 11/14/2016] [Indexed: 12/28/2022] Open
Abstract
HIV-1's Rev protein forms a homo-oligomeric adaptor complex linking viral RNAs to the cellular CRM1/Ran-GTP nuclear export machinery through the activity of Rev's prototypical leucine-rich nuclear export signal (NES). In this study, we used a functional fluorescently tagged Rev fusion protein as a platform to study the effects of modulating Rev NES identity, number, position, or strength on Rev subcellular trafficking, viral RNA nuclear export, and infectious virion production. We found that Rev activity was remarkably tolerant of diverse NES sequences, including supraphysiological NES (SNES) peptides that otherwise arrest CRM1 transport complexes at nuclear pores. Rev's ability to tolerate a SNES was both position and multimerization dependent, an observation consistent with a model wherein Rev self-association acts to transiently mask the NES peptide(s), thereby biasing Rev's trafficking into the nucleus. Combined imaging and functional assays also indicated that NES masking underpins Rev's well-known tendency to accumulate at the nucleolus, as well as Rev's capacity to activate optimal levels of late viral gene expression. We propose that Rev multimerization and NES masking regulates Rev's trafficking to and retention within the nucleus even prior to RNA binding. IMPORTANCE HIV-1 infects more than 34 million people worldwide causing >1 million deaths per year. Infectious virion production is activated by the essential viral Rev protein that mediates nuclear export of intron-bearing late-stage viral mRNAs. Rev's shuttling into and out of the nucleus is regulated by the antagonistic activities of both a peptide-encoded N-terminal nuclear localization signal and C-terminal nuclear export signal (NES). How Rev and related viral proteins balance strong import and export activities in order to achieve optimal levels of viral gene expression is incompletely understood. We provide evidence that multimerization provides a mechanism by which Rev transiently masks its NES peptide, thereby biasing its trafficking to and retention within the nucleus. Targeted pharmacological disruption of Rev-Rev interactions should perturb multiple Rev activities, both Rev-RNA binding and Rev's trafficking to the nucleus in the first place.
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Interactions between the HIV-1 Unspliced mRNA and Host mRNA Decay Machineries. Viruses 2016; 8:v8110320. [PMID: 27886048 PMCID: PMC5127034 DOI: 10.3390/v8110320] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/12/2016] [Accepted: 11/14/2016] [Indexed: 02/06/2023] Open
Abstract
The human immunodeficiency virus type-1 (HIV-1) unspliced transcript is used both as mRNA for the synthesis of structural proteins and as the packaged genome. Given the presence of retained introns and instability AU-rich sequences, this viral transcript is normally retained and degraded in the nucleus of host cells unless the viral protein REV is present. As such, the stability of the HIV-1 unspliced mRNA must be particularly controlled in the nucleus and the cytoplasm in order to ensure proper levels of this viral mRNA for translation and viral particle formation. During its journey, the HIV-1 unspliced mRNA assembles into highly specific messenger ribonucleoproteins (mRNPs) containing many different host proteins, amongst which are well-known regulators of cytoplasmic mRNA decay pathways such as up-frameshift suppressor 1 homolog (UPF1), Staufen double-stranded RNA binding protein 1/2 (STAU1/2), or components of miRNA-induced silencing complex (miRISC) and processing bodies (PBs). More recently, the HIV-1 unspliced mRNA was shown to contain N⁶-methyladenosine (m⁶A), allowing the recruitment of YTH N⁶-methyladenosine RNA binding protein 2 (YTHDF2), an m⁶A reader host protein involved in mRNA decay. Interestingly, these host proteins involved in mRNA decay were shown to play positive roles in viral gene expression and viral particle assembly, suggesting that HIV-1 interacts with mRNA decay components to successfully accomplish viral replication. This review summarizes the state of the art in terms of the interactions between HIV-1 unspliced mRNA and components of different host mRNA decay machineries.
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29
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The Life-Cycle of the HIV-1 Gag-RNA Complex. Viruses 2016; 8:v8090248. [PMID: 27626439 PMCID: PMC5035962 DOI: 10.3390/v8090248] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/30/2016] [Accepted: 09/02/2016] [Indexed: 12/16/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) replication is a highly regulated process requiring the recruitment of viral and cellular components to the plasma membrane for assembly into infectious particles. This review highlights the recent process of understanding the selection of the genomic RNA (gRNA) by the viral Pr55Gag precursor polyprotein, and the processes leading to its incorporation into viral particles.
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30
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Jayaraman B, Smith AM, Fernandes JD, Frankel AD. Oligomeric viral proteins: small in size, large in presence. Crit Rev Biochem Mol Biol 2016; 51:379-394. [PMID: 27685368 DOI: 10.1080/10409238.2016.1215406] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Viruses are obligate parasites that rely heavily on host cellular processes for replication. The small number of proteins typically encoded by a virus is faced with selection pressures that lead to the evolution of distinctive structural properties, allowing each protein to maintain its function under constraints such as small genome size, high mutation rate, and rapidly changing fitness conditions. One common strategy for this evolution is to utilize small building blocks to generate protein oligomers that assemble in multiple ways, thereby diversifying protein function and regulation. In this review, we discuss specific cases that illustrate how oligomerization is used to generate a single defined functional state, to modulate activity via different oligomeric states, or to generate multiple functional forms via different oligomeric states.
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Affiliation(s)
- Bhargavi Jayaraman
- a Department of Biochemistry and Biophysics , University of California , San Francisco , CA , USA
| | - Amber M Smith
- a Department of Biochemistry and Biophysics , University of California , San Francisco , CA , USA
| | - Jason D Fernandes
- b UC Santa Cruz Genomics Institute , Santa Cruz , CA , USA.,c Howard Hughes Medical Institute, University of California , Santa Cruz , CA , USA
| | - Alan D Frankel
- a Department of Biochemistry and Biophysics , University of California , San Francisco , CA , USA
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31
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Schröder HC, Ushijima H, Bek A, Merz H, Pfeifer K, Müller WEG. Inhibition of Formation of Rev-RRE Complex by Pyronin Y. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029300400205] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The interaction of pyronin Y, an RNA intercalating drug, with the binding of Rev protein from human immunodeficiency virus type 1 (HIV-1) to Rev-responsive element (RRE)-containing env RNA was studied. In gel retardation assays, recombinant Rev protein tightly bound to in vitro transcribed RRE RNA. Nitrocellulose-filter-binding studies revealed a dissociation constant of ≈(1–2) = 10−10M (Pfeifer et al., 1991). Pyronin Y efficiently suppressed formation of the Rev-RRE complex. At a concentration of 1 μg ml−1, complex formation was almost completely inhibited. Electron microscopy showed that Rev oligomerizes in the presence of RRE-containing RNA with the formation of short rod-like structures or long filaments, depending on the length of the transcript. Assembly of Rev protein along RRE-containing RNAs was abolished after addition of pyronin Y. Thus pyronin Y represents the first compound described to inhibit Rev-RRE complex formation.
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Affiliation(s)
- H. C. Schröder
- Institut für Physiologische Chemie, Universität, Duesbergweg 6, 6500 Mainz, Germany
| | - H. Ushijima
- AIDS Research Center, National Institute of Health, Gakuen 4-7-1, Musashimurayama-shi, Tokyo 208, Japan
| | - A. Bek
- Institut für Physiologische Chemie, Universität, Duesbergweg 6, 6500 Mainz, Germany
| | - H. Merz
- Institut für Physiologische Chemie, Universität, Duesbergweg 6, 6500 Mainz, Germany
| | - K. Pfeifer
- Institut für Physiologische Chemie, Universität, Duesbergweg 6, 6500 Mainz, Germany
| | - W. E. G. Müller
- Institut für Physiologische Chemie, Universität, Duesbergweg 6, 6500 Mainz, Germany
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32
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Kingsman SM, Kingsman AJ. Targets for Antiviral Chemotherapy: HIV Regulatory Proteins. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029000100202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- S. M. Kingsman
- Department of Biochemistry, South Parks Road, Coxford OX1 3QU
| | - A. J. Kingsman
- Department of Biochemistry, South Parks Road, Coxford OX1 3QU
- British Biotechnology Ltd, Watlington Road, Cowley, Oxford, UK
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33
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DiMattia MA, Watts NR, Cheng N, Huang R, Heymann JB, Grimes JM, Wingfield PT, Stuart DI, Steven AC. The Structure of HIV-1 Rev Filaments Suggests a Bilateral Model for Rev-RRE Assembly. Structure 2016; 24:1068-80. [PMID: 27265851 DOI: 10.1016/j.str.2016.04.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 04/21/2016] [Accepted: 04/25/2016] [Indexed: 11/24/2022]
Abstract
HIV-1 Rev protein mediates the nuclear export of viral RNA genomes. To do so, Rev oligomerizes cooperatively onto an RNA motif, the Rev response element (RRE), forming a complex that engages with the host nuclear export machinery. To better understand Rev oligomerization, we determined four crystal structures of Rev N-terminal domain dimers, which show that they can pivot about their dyad axis, giving crossing angles of 90° to 140°. In parallel, we performed cryoelectron microscopy of helical Rev filaments. Filaments vary from 11 to 15 nm in width, reflecting variations in dimer crossing angle. These structures contain additional density, indicating that C-terminal domains become partially ordered in the context of filaments. This conformational variability may be exploited in the assembly of RRE/Rev complexes. Our data also revealed a third interface between Revs, which offers an explanation for how the arrangement of Rev subunits adapts to the "A"-shaped architecture of the RRE in export-active complexes.
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Affiliation(s)
- Michael A DiMattia
- Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Headington OX3 7BN, UK
| | - Norman R Watts
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Naiqian Cheng
- Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rick Huang
- Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - J Bernard Heymann
- Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jonathan M Grimes
- Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Headington OX3 7BN, UK; Diamond House, Diamond Light Source, Harwell Science & Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Paul T Wingfield
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - David I Stuart
- Division of Structural Biology, Henry Wellcome Building for Genomic Medicine, University of Oxford, Roosevelt Drive, Headington OX3 7BN, UK; Diamond House, Diamond Light Source, Harwell Science & Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Alasdair C Steven
- Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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HIV-1 and M-PMV RNA Nuclear Export Elements Program Viral Genomes for Distinct Cytoplasmic Trafficking Behaviors. PLoS Pathog 2016; 12:e1005565. [PMID: 27070420 PMCID: PMC4829213 DOI: 10.1371/journal.ppat.1005565] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Accepted: 03/21/2016] [Indexed: 12/15/2022] Open
Abstract
Retroviruses encode cis-acting RNA nuclear export elements that override nuclear retention of intron-containing viral mRNAs including the full-length, unspliced genomic RNAs (gRNAs) packaged into assembling virions. The HIV-1 Rev-response element (RRE) recruits the cellular nuclear export receptor CRM1 (also known as exportin-1/XPO1) using the viral protein Rev, while simple retroviruses encode constitutive transport elements (CTEs) that directly recruit components of the NXF1(Tap)/NXT1(p15) mRNA nuclear export machinery. How gRNA nuclear export is linked to trafficking machineries in the cytoplasm upstream of virus particle assembly is unknown. Here we used long-term (>24 h), multicolor live cell imaging to directly visualize HIV-1 gRNA nuclear export, translation, cytoplasmic trafficking, and virus particle production in single cells. We show that the HIV-1 RRE regulates unique, en masse, Rev- and CRM1-dependent "burst-like" transitions of mRNAs from the nucleus to flood the cytoplasm in a non-localized fashion. By contrast, the CTE derived from Mason-Pfizer monkey virus (M-PMV) links gRNAs to microtubules in the cytoplasm, driving them to cluster markedly to the centrosome that forms the pericentriolar core of the microtubule-organizing center (MTOC). Adding each export element to selected heterologous mRNAs was sufficient to confer each distinct export behavior, as was directing Rev/CRM1 or NXF1/NXT1 transport modules to mRNAs using a site-specific RNA tethering strategy. Moreover, multiple CTEs per transcript enhanced MTOC targeting, suggesting that a cooperative mechanism links NXF1/NXT1 to microtubules. Combined, these results reveal striking, unexpected features of retroviral gRNA nucleocytoplasmic transport and demonstrate roles for mRNA export elements that extend beyond nuclear pores to impact gRNA distribution in the cytoplasm.
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Bose D, Gagnon J, Chebloune Y. Comparative Analysis of Tat-Dependent and Tat-Deficient Natural Lentiviruses. Vet Sci 2015; 2:293-348. [PMID: 29061947 PMCID: PMC5644649 DOI: 10.3390/vetsci2040293] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/24/2015] [Accepted: 08/24/2015] [Indexed: 01/10/2023] Open
Abstract
The emergence of human immunodeficiency virus (HIV) causing acquired immunodeficiency syndrome (AIDS) in infected humans has resulted in a global pandemic that has killed millions. HIV-1 and HIV-2 belong to the lentivirus genus of the Retroviridae family. This genus also includes viruses that infect other vertebrate animals, among them caprine arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), the prototypes of a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting both goat and sheep worldwide. Despite their long host-SRLV natural history, SRLVs were never found to be responsible for immunodeficiency in contrast to primate lentiviruses. SRLVs only replicate productively in monocytes/macrophages in infected animals but not in CD4+ T cells. The focus of this review is to examine and compare the biological and pathological properties of SRLVs as prototypic Tat-independent lentiviruses with HIV-1 as prototypic Tat-dependent lentiviruses. Results from this analysis will help to improve the understanding of why and how these two prototypic lentiviruses evolved in opposite directions in term of virulence and pathogenicity. Results may also help develop new strategies based on the attenuation of SRLVs to control the highly pathogenic HIV-1 in humans.
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Affiliation(s)
- Deepanwita Bose
- Pathogénèse et Vaccination Lentivirales, PAVAL Lab., Université Joseph Fourier Grenoble 1, Bat. NanoBio2, 570 rue de la Chimie, BP 53, 38041, Grenoble Cedex 9, France.
| | - Jean Gagnon
- Pathogénèse et Vaccination Lentivirales, PAVAL Lab., Université Joseph Fourier Grenoble 1, Bat. NanoBio2, 570 rue de la Chimie, BP 53, 38041, Grenoble Cedex 9, France.
| | - Yahia Chebloune
- Pathogénèse et Vaccination Lentivirales, PAVAL Lab., Université Joseph Fourier Grenoble 1, Bat. NanoBio2, 570 rue de la Chimie, BP 53, 38041, Grenoble Cedex 9, France.
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36
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Zhong F, Geng G, Chen B, Pan T, Li Q, Zhang H, Bai C. Identification of benzenesulfonamide quinoline derivatives as potent HIV-1 replication inhibitors targeting Rev protein. Org Biomol Chem 2015; 13:1792-9. [PMID: 25503645 DOI: 10.1039/c4ob02247e] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) Rev protein facilitates the export of viral RNA from nucleus to cytoplasm, which is a key step in HIV-1 pathogenesis and transmission. In this study, we have screened a commercial library and identified the hit compound 1 bearing a benzenesulfonamide quinoline scaffold that inhibited Rev activity and HIV-1 infectivity. Compounds bearing this scaffold were synthesized and their SAR was studied. We identified compound 20 with low toxicity and potent activity to inhibit HIV-1 replication by affecting Rev function.
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Affiliation(s)
- Fudi Zhong
- Institute of Human Virology, Key Laboratory of Tropical Diseases Control of Ministry of Education of China, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
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37
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Rojas-Araya B, Ohlmann T, Soto-Rifo R. Translational Control of the HIV Unspliced Genomic RNA. Viruses 2015; 7:4326-51. [PMID: 26247956 PMCID: PMC4576183 DOI: 10.3390/v7082822] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 05/18/2015] [Accepted: 07/17/2015] [Indexed: 01/16/2023] Open
Abstract
Post-transcriptional control in both HIV-1 and HIV-2 is a highly regulated process that commences in the nucleus of the host infected cell and finishes by the expression of viral proteins in the cytoplasm. Expression of the unspliced genomic RNA is particularly controlled at the level of RNA splicing, export, and translation. It appears increasingly obvious that all these steps are interconnected and they result in the building of a viral ribonucleoprotein complex (RNP) that must be efficiently translated in the cytosolic compartment. This review summarizes our knowledge about the genesis, localization, and expression of this viral RNP.
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Affiliation(s)
- Bárbara Rojas-Araya
- Molecular and Cellular Virology Laboratory, Program of Virology, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Independencia 834100, Santiago, Chile.
| | - Théophile Ohlmann
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon 69007, France.
- Inserm, U1111, Lyon 69007, France.
- Ecole Normale Supérieure de Lyon, Lyon 69007, France.
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69007, France.
- CNRS, UMR5308, Lyon 69007, France.
| | - Ricardo Soto-Rifo
- Molecular and Cellular Virology Laboratory, Program of Virology, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Independencia 834100, Santiago, Chile.
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HIV Rev Assembly on the Rev Response Element (RRE): A Structural Perspective. Viruses 2015; 7:3053-75. [PMID: 26075509 PMCID: PMC4488727 DOI: 10.3390/v7062760] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 06/05/2015] [Indexed: 01/18/2023] Open
Abstract
HIV-1 Rev is an ~13 kD accessory protein expressed during the early stage of virus replication. After translation, Rev enters the nucleus and binds the Rev response element (RRE), a ~350 nucleotide, highly structured element embedded in the env gene in unspliced and singly spliced viral RNA transcripts. Rev-RNA assemblies subsequently recruit Crm1 and other cellular proteins to form larger complexes that are exported from the nucleus. Once in the cytoplasm, the complexes dissociate and unspliced and singly-spliced viral RNAs are packaged into nascent virions or translated into viral structural proteins and enzymes, respectively. Rev binding to the RRE is a complex process, as multiple copies of the protein assemble on the RNA in a coordinated fashion via a series of Rev-Rev and Rev-RNA interactions. Our understanding of the nature of these interactions has been greatly advanced by recent studies using X-ray crystallography, small angle X-ray scattering (SAXS) and single particle electron microscopy as well as biochemical and genetic methodologies. These advances are discussed in detail in this review, along with perspectives on development of antiviral therapies targeting the HIV-1 RRE.
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Quinn CM, Lu M, Suiter CL, Hou G, Zhang H, Polenova T. Magic angle spinning NMR of viruses. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 86-87:21-40. [PMID: 25919197 PMCID: PMC4413014 DOI: 10.1016/j.pnmrs.2015.02.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/27/2015] [Accepted: 02/08/2015] [Indexed: 05/02/2023]
Abstract
Viruses, relatively simple pathogens, are able to replicate in many living organisms and to adapt to various environments. Conventional atomic-resolution structural biology techniques, X-ray crystallography and solution NMR spectroscopy provided abundant information on the structures of individual proteins and nucleic acids comprising viruses; however, viral assemblies are not amenable to analysis by these techniques because of their large size, insolubility, and inherent lack of long-range order. In this article, we review the recent advances in magic angle spinning NMR spectroscopy that enabled atomic-resolution analysis of structure and dynamics of large viral systems and give examples of several exciting case studies.
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Affiliation(s)
- Caitlin M Quinn
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States.
| | - Manman Lu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States.
| | - Christopher L Suiter
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States.
| | - Guangjin Hou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States.
| | - Huilan Zhang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States.
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Ave., Pittsburgh, PA 15261, United States.
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40
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RNA Export through the NPC in Eukaryotes. Genes (Basel) 2015; 6:124-49. [PMID: 25802992 PMCID: PMC4377836 DOI: 10.3390/genes6010124] [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] [Received: 11/28/2014] [Revised: 02/27/2015] [Accepted: 03/10/2015] [Indexed: 02/08/2023] Open
Abstract
In eukaryotic cells, RNAs are transcribed in the nucleus and exported to the cytoplasm through the nuclear pore complex. The RNA molecules that are exported from the nucleus into the cytoplasm include messenger RNAs (mRNAs), ribosomal RNAs (rRNAs), transfer RNAs (tRNAs), small nuclear RNAs (snRNAs), micro RNAs (miRNAs), and viral mRNAs. Each RNA is transported by a specific nuclear export receptor. It is believed that most of the mRNAs are exported by Nxf1 (Mex67 in yeast), whereas rRNAs, snRNAs, and a certain subset of mRNAs are exported in a Crm1/Xpo1-dependent manner. tRNAs and miRNAs are exported by Xpot and Xpo5. However, multiple export receptors are involved in the export of some RNAs, such as 60S ribosomal subunit. In addition to these export receptors, some adapter proteins are required to export RNAs. The RNA export system of eukaryotic cells is also used by several types of RNA virus that depend on the machineries of the host cell in the nucleus for replication of their genome, therefore this review describes the RNA export system of two representative viruses. We also discuss the NPC anchoring-dependent mRNA export factors that directly recruit specific genes to the NPC.
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41
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Islam A, Schulz S, Afroz S, Babiuk LA, van Drunen Littel-van den Hurk S. Interaction of VP8 with mRNAs of bovine herpesvirus-1. Virus Res 2015; 197:116-26. [DOI: 10.1016/j.virusres.2014.12.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 12/09/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
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42
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Boons E, Li G, Vanstreels E, Vercruysse T, Pannecouque C, Vandamme AM, Daelemans D. A stably expressed llama single-domain intrabody targeting Rev displays broad-spectrum anti-HIV activity. Antiviral Res 2014; 112:91-102. [DOI: 10.1016/j.antiviral.2014.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 01/24/2023]
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43
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44
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Byun H, Gou Y, Zook A, Lozano MM, Dudley JP. ERAD and how viruses exploit it. Front Microbiol 2014; 5:330. [PMID: 25071743 PMCID: PMC4080680 DOI: 10.3389/fmicb.2014.00330] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 06/16/2014] [Indexed: 01/09/2023] Open
Abstract
Endoplasmic reticulum (ER)-associated degradation (ERAD) is a universally important process among eukaryotic cells. ERAD is necessary to preserve cell integrity since the accumulation of defective proteins results in diseases associated with neurological dysfunction, cancer, and infections. This process involves recognition of misfolded or misassembled proteins that have been translated in association with ER membranes. Recognition of ERAD substrates leads to their extraction through the ER membrane (retrotranslocation or dislocation), ubiquitination, and destruction by cytosolic proteasomes. This review focuses on ERAD and its components as well as how viruses use this process to promote their replication and to avoid the immune response.
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Affiliation(s)
- Hyewon Byun
- Department of Molecular Biosciences, Center for Infectious Diseases and Institute for Cellular and Molecular Biology, The University of Texas at Austin Austin, TX, USA
| | - Yongqiang Gou
- Department of Molecular Biosciences, Center for Infectious Diseases and Institute for Cellular and Molecular Biology, The University of Texas at Austin Austin, TX, USA
| | - Adam Zook
- Department of Molecular Biosciences, Center for Infectious Diseases and Institute for Cellular and Molecular Biology, The University of Texas at Austin Austin, TX, USA
| | - Mary M Lozano
- Department of Molecular Biosciences, Center for Infectious Diseases and Institute for Cellular and Molecular Biology, The University of Texas at Austin Austin, TX, USA
| | - Jaquelin P Dudley
- Department of Molecular Biosciences, Center for Infectious Diseases and Institute for Cellular and Molecular Biology, The University of Texas at Austin Austin, TX, USA
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45
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Murine leukemia virus uses TREX components for efficient nuclear export of unspliced viral transcripts. Viruses 2014; 6:1135-48. [PMID: 24618812 PMCID: PMC3970143 DOI: 10.3390/v6031135] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 02/21/2014] [Accepted: 02/25/2014] [Indexed: 11/17/2022] Open
Abstract
Previously we reported that nuclear export of both unspliced and spliced murine leukemia virus (MLV) transcripts depends on the nuclear export factor (NXF1) pathway. Although the mRNA export complex TREX, which contains Aly/REF, UAP56, and the THO complex, is involved in the NXF1-mediated nuclear export of cellular mRNAs, its contribution to the export of MLV mRNA transcripts remains poorly understood. Here, we studied the involvement of TREX components in the export of MLV transcripts. Depletion of UAP56, but not Aly/REF, reduced the level of both unspliced and spliced viral transcripts in the cytoplasm. Interestingly, depletion of THO components, including THOC5 and THOC7, affected only unspliced viral transcripts in the cytoplasm. Moreover, the RNA immunoprecipitation assay showed that only the unspliced viral transcript interacted with THOC5. These results imply that MLV requires UAP56, THOC5 and THOC7, in addition to NXF1, for nuclear export of viral transcripts. Given that naturally intronless mRNAs, but not bulk mRNAs, require THOC5 for nuclear export, it is plausible that THOC5 plays a key role in the export of unspliced MLV transcripts.
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46
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Murine leukemia virus uses NXF1 for nuclear export of spliced and unspliced viral transcripts. J Virol 2014; 88:4069-82. [PMID: 24478440 DOI: 10.1128/jvi.03584-13] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
UNLABELLED Intron-containing mRNAs are subject to restricted nuclear export in higher eukaryotes. Retroviral replication requires the nucleocytoplasmic transport of both spliced and unspliced RNA transcripts, and RNA export mechanisms of gammaretroviruses are poorly characterized. Here, we report the involvement of the nuclear export receptor NXF1/TAP in the nuclear export of gammaretroviral RNA transcripts. We identified a conserved cis-acting element in the pol gene of gammaretroviruses, including murine leukemia virus (MLV) and xenotropic murine leukemia virus (XMRV), named the CAE (cytoplasmic accumulation element). The CAE enhanced the cytoplasmic accumulation of viral RNA transcripts and the expression of viral proteins without significantly affecting the stability, splicing, or translation efficiency of the transcripts. Insertion of the CAE sequence also facilitated Rev-independent HIV Gag expression. We found that the CAE sequence interacted with NXF1, whereas disruption of NXF1 ablated CAE function. Thus, the CAE sequence mediates the cytoplasmic accumulation of gammaretroviral transcripts in an NXF1-dependent manner. Disruption of NXF1 expression impaired cytoplasmic accumulations of both spliced and unspliced RNA transcripts of XMRV and MLV, resulting in their nuclear retention or degradation. Thus, our results demonstrate that gammaretroviruses use NXF1 for the cytoplasmic accumulation of both spliced and nonspliced viral RNA transcripts. IMPORTANCE Murine leukemia virus (MLV) has been studied as one of the classic models of retrovirology. Although unspliced host messenger RNAs are rarely exported from the nucleus, MLV actively exports unspliced viral RNAs to the cytoplasm. Despite extensive studies, how MLV achieves this difficult task has remained a mystery. Here, we have studied the RNA export mechanism of MLV and found that (i) the genome contains a sequence which supports the efficient nuclear export of viral RNAs, (ii) the cellular factor NXF1 is involved in the nuclear export of both spliced and unspliced viral RNAs, and, finally, (iii) depletion of NXF1 results in nuclear retention or degradation of viral RNAs. Our study provides a novel insight into MLV nuclear export.
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47
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Raina S, Chande AG, Baba M, Mukhopadhyaya R. A reporter based single step assay for evaluation of inhibitors targeting HIV-1 Rev-RRE interaction. Virusdisease 2014; 25:101-6. [PMID: 24426316 DOI: 10.1007/s13337-013-0166-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 09/17/2013] [Indexed: 11/26/2022] Open
Abstract
Human immunodeficiency virus regulatory protein Rev (regulator of viral expression) is translated from a monocistronic transcript produced early in the viral replication cycle. Rev binds to the cis-acting, highly structured viral RNA sequence Rev response element (RRE) and the Rev-RRE complex primarily controls nucleocytoplasmic transport of viral RNAs. Inhibition of Rev-RRE interaction therefore is an attractive target to block viral transport. We have developed a stable cell line carrying a lentiviral vector harboring a rev gene and a co-linear Rev-dependent GFP/luciferase reporter gene cassette and thus constitutively expressing the reporter proteins. Dose-dependent luciferase activity inhibition in the indicator cell line by known small molecule inhibitors Proflavin and K37 established the specificity of the assay. This novel single step assay, that involves use of very small amount of reagents/cells and addition of test material as the only manipulation, can therefore be useful for screening therapeutically potential Rev-RRE interaction inhibitors.
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Affiliation(s)
- Sumeer Raina
- Virology Laboratory, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, 410 210 India
| | - Ajit G Chande
- Virology Laboratory, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, 410 210 India ; Immunology Group, ICGEB, New Delhi, India
| | - Masanori Baba
- Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Robin Mukhopadhyaya
- Virology Laboratory, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, 410 210 India
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48
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Hutson TH, Foster E, Moon LDF, Yáñez-Muñoz RJ. Lentiviral vector-mediated RNA silencing in the central nervous system. Hum Gene Ther Methods 2013; 25:14-32. [PMID: 24090197 DOI: 10.1089/hgtb.2013.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
RNA silencing is an established method for investigating gene function and has attracted particular interest because of the potential for generating RNA-based therapeutics. Using lentiviral vectors as an efficient delivery system that offers stable, long-term expression in postmitotic cells further enhances the applicability of an RNA-based gene therapy for the CNS. In this review we provide an overview of both lentiviral vectors and RNA silencing along with design considerations for generating lentiviral vectors capable of RNA silencing. We go on to describe the current preclinical data regarding lentiviral vector-mediated RNA silencing for CNS disorders and discuss the concerns of side effects associated with lentiviral vectors and small interfering RNAs and how these might be mitigated.
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Affiliation(s)
- Thomas H Hutson
- 1 Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King's College London , Guy's Campus, London SE1 1UL, United Kingdom
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49
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Fang X, Wang J, O’Carroll IP, Mitchell M, Zuo X, Wang Y, Yu P, Liu Y, Rausch JW, Dyba MA, Kjems J, Schwieters CD, Seifert S, Winans RE, Watts NR, Stahl SJ, Wingfield PT, Byrd RA, Le Grice SF, Rein A, Wang YX. An unusual topological structure of the HIV-1 Rev response element. Cell 2013; 155:594-605. [PMID: 24243017 PMCID: PMC3918456 DOI: 10.1016/j.cell.2013.10.008] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 08/22/2013] [Accepted: 10/07/2013] [Indexed: 01/15/2023]
Abstract
Nuclear export of unspliced and singly spliced viral mRNA is a critical step in the HIV life cycle. The structural basis by which the virus selects its own mRNA among more abundant host cellular RNAs for export has been a mystery for more than 25 years. Here, we describe an unusual topological structure that the virus uses to recognize its own mRNA. The viral Rev response element (RRE) adopts an "A"-like structure in which the two legs constitute two tracks of binding sites for the viral Rev protein and position the two primary known Rev-binding sites ~55 Å apart, matching the distance between the two RNA-binding motifs in the Rev dimer. Both the legs of the "A" and the separation between them are required for optimal RRE function. This structure accounts for the specificity of Rev for the RRE and thus the specific recognition of the viral RNA.
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MESH Headings
- Active Transport, Cell Nucleus
- Base Sequence
- Binding Sites
- Cell Nucleus/metabolism
- HEK293 Cells
- HIV-1/chemistry
- HIV-1/genetics
- Humans
- Molecular Sequence Data
- Nuclear Pore/metabolism
- Nucleic Acid Conformation
- RNA Folding
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Viral/chemistry
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Scattering, Small Angle
- X-Ray Diffraction
- rev Gene Products, Human Immunodeficiency Virus/chemistry
- rev Gene Products, Human Immunodeficiency Virus/genetics
- rev Gene Products, Human Immunodeficiency Virus/metabolism
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Affiliation(s)
- Xianyang Fang
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Jinbu Wang
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Ina P. O’Carroll
- Retroviral Assembly Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Michelle Mitchell
- RT Biochemistry Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Xiaobing Zuo
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Yi Wang
- RT Biochemistry Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Ping Yu
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
- Structural Biophysics Laboratory, SAIC-Frederick, Frederick, MD 21702, USA
| | - Yu Liu
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Jason W. Rausch
- RT Biochemistry Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Marzena A. Dyba
- Structural Biophysics Laboratory, SAIC-Frederick, Frederick, MD 21702, USA
| | - Jørgen Kjems
- Department of Molecular Biology, University of Aarhus, DK-8000 Aarhus C, Denmark
| | - Charles D. Schwieters
- Division of Computational Bioscience, Center for Informational Technology, National Institutes of Health, Bethesda, MD 20892, USA
| | - Soenke Seifert
- X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Randall E. Winans
- X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Norman R. Watts
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephen J. Stahl
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Paul T. Wingfield
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - R. Andrew Byrd
- Macromolecular NMR Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Stuart F.J. Le Grice
- RT Biochemistry Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Alan Rein
- Retroviral Assembly Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Yun-Xing Wang
- Protein-Nucleic Acid Interaction Section, Structural Biophysics Laboratory, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
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50
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Translation of pre-spliced RNAs in the nuclear compartment generates peptides for the MHC class I pathway. Proc Natl Acad Sci U S A 2013; 110:17951-6. [PMID: 24082107 DOI: 10.1073/pnas.1309956110] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The scanning of maturing mRNAs by ribosomes plays a key role in the mRNA quality control process. When ribosomes first engage with the newly synthesized mRNA, and if peptides are produced, is unclear, however. Here we show that ribosomal scanning of prespliced mRNAs occurs in the nuclear compartment, and that this event produces peptide substrates for the MHC class I pathway. Inserting antigenic peptide sequences in introns that are spliced out before the mRNAs exit the nuclear compartment results in an equal amount of antigenic peptide products as when the peptides are encoded from the main open reading frame (ORF). Taken together with the detection of intron-encoded nascent peptides and RPS6/RPL7-carrying complexes in the perinucleolar compartment, these results show that peptides are produced by a translation event occurring before mRNA splicing. This suggests that ribosomes occupy and scan mRNAs early in the mRNA maturation process, and suggests a physiological role for nuclear mRNA translation, and also helps explain how the immune system tolerates peptides derived from tissue-specific mRNA splice variants.
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