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Sztuba-Solinska J, Diaz L, Kumar MR, Kolb G, Wiley MR, Jozwick L, Kuhn JH, Palacios G, Radoshitzky SR, J Le Grice SF, Johnson RF. A small stem-loop structure of the Ebola virus trailer is essential for replication and interacts with heat-shock protein A8. Nucleic Acids Res 2016; 44:9831-9846. [PMID: 27651462 PMCID: PMC5175359 DOI: 10.1093/nar/gkw825] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 09/07/2016] [Accepted: 09/08/2016] [Indexed: 01/03/2023] Open
Abstract
Ebola virus (EBOV) is a single-stranded negative-sense RNA virus belonging to the Filoviridae family. The leader and trailer non-coding regions of the EBOV genome likely regulate its transcription, replication, and progeny genome packaging. We investigated the cis-acting RNA signals involved in RNA–RNA and RNA–protein interactions that regulate replication of eGFP-encoding EBOV minigenomic RNA and identified heat shock cognate protein family A (HSC70) member 8 (HSPA8) as an EBOV trailer-interacting host protein. Mutational analysis of the trailer HSPA8 binding motif revealed that this interaction is essential for EBOV minigenome replication. Selective 2′-hydroxyl acylation analyzed by primer extension analysis of the secondary structure of the EBOV minigenomic RNA indicates formation of a small stem-loop composed of the HSPA8 motif, a 3′ stem-loop (nucleotides 1868–1890) that is similar to a previously identified structure in the replicative intermediate (RI) RNA and a panhandle domain involving a trailer-to-leader interaction. Results of minigenome assays and an EBOV reverse genetic system rescue support a role for both the panhandle domain and HSPA8 motif 1 in virus replication.
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Affiliation(s)
- Joanna Sztuba-Solinska
- RT Biochemistry Section, Basic Research Laboratory, National Cancer Institute-Frederick, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Larissa Diaz
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Mia R Kumar
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Gaëlle Kolb
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Michael R Wiley
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA
| | - Lucas Jozwick
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA
| | - Jens H Kuhn
- Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Gustavo Palacios
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA
| | - Sheli R Radoshitzky
- United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702, USA
| | - Stuart F J Le Grice
- RT Biochemistry Section, Basic Research Laboratory, National Cancer Institute-Frederick, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
| | - Reed F Johnson
- Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Disease, National Institutes of Health, Fort Detrick, Frederick, MD 21702, USA
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DNA topoisomerase 1 facilitates the transcription and replication of the Ebola virus genome. J Virol 2013; 87:8862-9. [PMID: 23658456 DOI: 10.1128/jvi.03544-12] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ebola virus (EBOV) protein L (EBOL) acts as a viral RNA-dependent RNA polymerase. To better understand the mechanisms underlying the transcription and replication of the EBOV genome, we sought to identify cellular factors involved in these processes via their coimmunoprecipitation with EBOL and by mass spectrometry. Of 65 candidate proteins identified, we focused on DNA topoisomerase 1 (TOP1), which localizes to the nucleus and unwinds helical DNA. We found that in the presence of EBOL, TOP1 colocalizes and interacts with EBOL in the cytoplasm, where transcription and replication of the EBOV genome occur. Knockdown of TOP1 markedly reduced virus replication and viral polymerase activity. We also found that the phosphodiester bridge-cleaving and recombination activities of TOP1 are required for the polymerase activity of EBOL. These results demonstrate that TOP1 is an important cellular factor for the transcription and replication of the EBOV genome and, as such, plays a key role in the EBOV life cycle.
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Ducloux C, Mougel M, Goldschmidt V, Didierlaurent L, Marquet R, Isel C. A pyrophosphatase activity associated with purified HIV-1 particles. Biochimie 2012; 94:2498-507. [PMID: 22766015 DOI: 10.1016/j.biochi.2012.06.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 06/22/2012] [Indexed: 01/17/2023]
Abstract
Treatment of HIV-1 with nucleoside reverse transcription inhibitors leads to the emergence of resistance mutations in the reverse transcriptase (RT) gene. Resistance to 3'-azido-3'-deoxythymidine (AZT) and to a lesser extent to 2'-3'-didehydro-2'-3'-dideoxythymidine is mediated by phosphorolytic excision of the chain terminator. Wild-type RT excises AZT by pyrophosphorolysis, while thymidine-associated resistance mutations in RT (TAMs) favour ATP as the donor substrate. However, in vitro, resistant RT still uses pyrophosphate more efficiently than ATP. We performed in vitro (-) strong-stop DNA synthesis experiments, with wild-type and AZT-resistant HIV-1 RTs, in the presence of physiologically relevant pyrophosphate and/or ATP concentrations and found that in the presence of pyrophosphate, ATP and AZTTP, TAMs do not enhance in vitro (-) strong-stop DNA synthesis. We hypothesized that utilisation of ATP in vivo is driven by intrinsic low pyrophosphate concentrations within the reverse transcription complex, which could be explained by the packaging of a cellular pyrophosphatase. We showed that over-expressed flagged-pyrophosphatase was associated with HIV-1 viral-like particles. In addition, we demonstrated that when HIV-1 particles were purified in order to avoid cellular microvesicle contamination, a pyrophosphatase activity was specifically associated to them. The presence of a pyrophosphatase activity in close proximity to the reverse transcription complex is most likely advantageous to the virus, even in the absence of any drug pressure.
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Affiliation(s)
- Céline Ducloux
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, 15 Rue René Descartes, 67084 Strasbourg, France.
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Khurana B, Zhuang L, Moitra PK, Stantchev TS, Broder CC, Cutler ML, D'Arpa P. Human TOP1 residues implicated in species specificity of HIV-1 infection are required for interaction with BTBD2, and RNAi of BTBD2 in old world monkey and human cells increases permissiveness to HIV-1 infection. Virol J 2010; 7:332. [PMID: 21092135 PMCID: PMC3002306 DOI: 10.1186/1743-422x-7-332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Accepted: 11/20/2010] [Indexed: 11/29/2022] Open
Abstract
Background Host determinants of HIV-1 viral tropism include factors from producer cells that affect the efficiency of productive infection and factors in target cells that block infection after viral entry. TRIM5α restricts HIV-1 infection at an early post-entry step through a mechanism associated with rapid disassembly of the retroviral capsid. Topoisomerase I (TOP1) appears to play a role in HIV-1 viral tropism by incorporating into or otherwise modulating virions affecting the efficiency of a post-entry step, as the expression of human TOP1 in African Green Monkey (AGM) virion-producing cells increased the infectivity of progeny virions by five-fold. This infectivity enhancement required human TOP1 residues 236 and 237 as their replacement with the AGM counterpart residues abolished the infectivity enhancement. Our previous studies showed that TOP1 interacts with BTBD1 and BTBD2, two proteins which co-localize with the TRIM5α splice variant TRIM5δ in cytoplasmic bodies. Because BTBD1 and BTBD2 interact with one HIV-1 viral tropism factor, TOP1, and co-localize with a splice variant of another, we investigated the potential involvement of BTBD1 and BTBD2 in HIV-1 restriction. Results We show that the interaction of BTBD1 and BTBD2 with TOP1 requires hu-TOP1 residues 236 and 237, the same residues required to enhance the infectivity of progeny virions when hu-TOP1 is expressed in AGM producer cells. Additionally, interference with the expression of BTBD2 in AGM and human 293T target cells increased their permissiveness to HIV-1 infection two- to three-fold. Conclusions These results do not exclude the possibility that BTBD2 may modestly restrict HIV-1 infection via colocation with TRIM5 variants in cytoplasmic bodies.
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Affiliation(s)
- Bharat Khurana
- Department of Pathology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
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5
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Warren K, Warrilow D, Meredith L, Harrich D. Reverse Transcriptase and Cellular Factors: Regulators of HIV-1 Reverse Transcription. Viruses 2009; 1:873-94. [PMID: 21994574 PMCID: PMC3185528 DOI: 10.3390/v1030873] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/06/2009] [Accepted: 11/09/2009] [Indexed: 01/16/2023] Open
Abstract
There is ample evidence that synthesis of HIV-1 proviral DNA from the viral RNA genome during reverse transcription requires host factors. However, only a few cellular proteins have been described in detail that affect reverse transcription and interact with reverse transcriptase (RT). HIV-1 integrase is an RT binding protein and a number of IN-binding proteins including INI1, components of the Sin3a complex, and Gemin2 affect reverse transcription. In addition, recent studies implicate the cellular proteins HuR, AKAP149, and DNA topoisomerase I in reverse transcription through an interaction with RT. In this review we will consider interactions of reverse transcription complex with viral and cellular factors and how they affect the reverse transcription process.
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Affiliation(s)
- Kylie Warren
- Division of Infectious Diseases, Queensland Institute of Medical Research, Brisbane, QLD, Australia; E-Mails: (K.W.); (D.W.); (L.M.)
- School of Natural Sciences, University of Western Sydney, Hawkesbury, NSW, Australia
| | - David Warrilow
- Division of Infectious Diseases, Queensland Institute of Medical Research, Brisbane, QLD, Australia; E-Mails: (K.W.); (D.W.); (L.M.)
| | - Luke Meredith
- Division of Infectious Diseases, Queensland Institute of Medical Research, Brisbane, QLD, Australia; E-Mails: (K.W.); (D.W.); (L.M.)
- Griffith Medical Research College, a joint program of Griffith University and the Queensland Institute of Medical Research, QIMR, Herston, QLD, 4006, Australia
| | - David Harrich
- Division of Infectious Diseases, Queensland Institute of Medical Research, Brisbane, QLD, Australia; E-Mails: (K.W.); (D.W.); (L.M.)
- Griffith Medical Research College, a joint program of Griffith University and the Queensland Institute of Medical Research, QIMR, Herston, QLD, 4006, Australia
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +61-7-3845-36791; Fax: +61-7-3362-0107
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6
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Shoya Y, Tokunaga K, Sawa H, Maeda M, Ueno T, Yoshikawa T, Hasegawa H, Sata T, Kurata T, Hall WW, Cullen BR, Takahashi H. Human topoisomerase I promotes HIV-1 proviral DNA synthesis: implications for the species specificity and cellular tropism of HIV-1 infection. Proc Natl Acad Sci U S A 2003; 100:8442-7. [PMID: 12829794 PMCID: PMC166248 DOI: 10.1073/pnas.1430827100] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Although HIV type 1 (HIV-1) cannot efficiently replicate in simian cells, the mechanism(s) involved in the restriction of virus tropism remain unclear. To investigate this, we have focused on the identification of human cellular factors that can influence the infectivity of HIV-1 derived from African green monkey producer cells. Whereas the infectivity of HIV-1 derived from such cells was only 10-15% of that of human cell-derived virus, expression of human topoisomerase I in the African green monkey cells resulted in a 5-fold increase of the infectivity of progeny HIV-1 virions. Replacement of glutamate-236 and asparagine-237 of human topoisomerase I with the corresponding residues (aspartate and serine, respectively) of the African green monkey enzyme abolished this enhancement of HIV-1 infectivity. This positive effect of human topoisomerase I expression in the African green monkey producer cells seemed to result from the promotion of HIV-1 cDNA synthesis. Thus, human topoisomerase I plays an important role in HIV-1 replication and infectivity, and differences in the species specificity of HIV-1 infection can at least in part be attributed to differences in topoisomerase I activities.
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Affiliation(s)
- Yuko Shoya
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Kenzo Tokunaga
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
- To whom correspondence should be addressed. E-mail:
or
| | - Hirofumi Sawa
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Masae Maeda
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Tomonori Ueno
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Tomoki Yoshikawa
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Hideki Hasegawa
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Tetsutaro Sata
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Takeshi Kurata
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - William W. Hall
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Bryan R. Cullen
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
| | - Hidehiro Takahashi
- Department of Pathology, National Institute of
Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan;
Laboratory of Molecular and Cellular
Pathology, Hokkaido University School of Medicine, Sapporo 060-8638, Japan;
Core Research for Evolutional Science and
Technology, Japan Science and Technology Corporation, 4-1-8 Honcho, Kawaguchi
City, Japan; Department of Medical Microbiology,
Conway Institute of Biomolecular and Biomedical Research, University College
Dublin, Belfield, Dublin 4, Ireland; and
Department of Molecular Genetics and Microbiology
and Howard Hughes Medical Institute, Duke University Medical Center, Durham,
NC 27710
- To whom correspondence should be addressed. E-mail:
or
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7
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Takahashi H, Sawa H, Hasegawa H, Sata T, Hall W, Kurata T. Binding and dissociation of human topoisomerase I with hairpin-loop RNAs: implications for the regulation of HIV-1 replication. Biochem Biophys Res Commun 2002; 297:593-9. [PMID: 12270136 DOI: 10.1016/s0006-291x(02)02247-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cellular topoisomerase I has been reported to be present in retroviral particles and to enhance viral cDNA synthesis; however, the mechanisms involved remain unknown. In the present study, it has been demonstrated that human topoisomerase I combines with a stem-loop RNA and that the bound topoisomerase I can be dissociated from RNA substrates in the presence of ATP. In addition, in vitro cleaved synthetic RNA bound by topoisomerase I is subsequently relegated when the topoisomerase I is dissociated by ATP. A mechanism is proposed in which human topoisomerase I is carried into virions and regulates the repair of genomic RNA by its ligation activity.
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Affiliation(s)
- Hidehiro Takahashi
- Department of Pathology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan.
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8
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Takahashi H, Sawa H, Hasegawa H, Shoya Y, Sata T, Hall WW, Nagashima K, Kurata T. Topoisomerase I and ATP activate cDNA synthesis of human immunodeficiency virus type 1. Biochem Biophys Res Commun 2002; 294:509-17. [PMID: 12051740 DOI: 10.1016/s0006-291x(02)00503-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Replication of human immunodeficiency virus type 1 (HIV-1) is regulated at reverse transcription. Cellular topoisomerase I has been reported to be carried into HIV-1 virions and enhance cDNA synthesis in vitro, suggesting that topoisomerase I expressed in virus producer cells regulates reverse transcription. Here, by employing both indicator cell assay and endogenous reverse transcription (ERT) assay, we show that topoisomerase I and adenosine triphosphate (ATP) enhanced cDNA synthesis of HIV-1. In addition, topoisomerase I mutants, R488A and K532A, lacking enzymatic activity, attenuated the efficiency of cDNA synthesis and resulted in inhibition of the infectivity of HIV-1, suggesting that the activity of topoisomerase I lacking in these mutants is indispensable for the cDNA synthesis in the HIV-1 replication process. Furthermore, ATP could dissociate topoisomerase I from the topoisomerase I-RNA complex and enhance cDNA synthesis in vitro. These findings suggest that cellular topoisomerase I and ATP play a pivotal role in the synthesis of cDNA of HIV-1.
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Affiliation(s)
- Hidehiro Takahashi
- Department of Pathology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan.
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9
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Takahashi H, Sawa H, Hasegawa H, Sata T, Hall WW, Nagashima K, Kurata T. Reconstitution of cleavage of human immunodeficiency virus type-1 (HIV-1) RNAs. Biochem Biophys Res Commun 2002; 293:1084-91. [PMID: 12051771 DOI: 10.1016/s0006-291x(02)00345-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A human immunodeficiency virus type 1 (HIV-1) particle contains approximately 1200 molecules of gag proteins and two copies of a 9.2-kb genomic RNA which has been reported to be dimerized and rapidly cleaved and to form a complex with a nucleocapsid protein, p7 (NCp7), during viral budding. These suggest that the cleavage can be reconstituted with gag proteins in vitro. Here we show that the p15(gag) coding region of viral RNA is fragmented in viral particles and that in vitro-synthesized RNA transcripts of HIV-1 undergo cleavage which is activated by NCp7 and other factors. Single-stranded oligoribonucleotides were cleaved between C and A or U and A, leaving 2',3'-cyclic phosphate and 5'-hydroxyl termini. These findings might explain the rapid degradation of genomic RNAs in HIV-1 particles.
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Affiliation(s)
- Hidehiro Takahashi
- Department of Pathology, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan.
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10
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Takahashi H, Iwata T, Kitagawa Y, Shoya Y, Takahashi RH, Nagashima K, Kurata T. Monoclonal antibodies against topoisomerase I suppressed DNA relaxation and HIV-1 cDNA synthesis. Hybridoma (Larchmt) 2000; 19:331-4. [PMID: 11001406 DOI: 10.1089/027245700429882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) virion is known to carry a number of cellular components including cellular topoisomerase I. Previously, we have demonstrated that topoisomerase I enhances HIV-1 cDNA synthesis in reverse transcription (RT) assays in vitro. In the present study, we have produced six monoclonal antibodies (MAbs) against human topoisomerase I. The MAbs suppressed nicking/closing of supercoiled DNA and cDNA synthesis in an endogenous reverse transcription (ERT) assay using a detergent-disrupted HIV-1 virion. Thus, the results suggest that topoisomerase I plays an important role in RNA-directed DNA polymerization.
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Affiliation(s)
- H Takahashi
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan.
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11
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Sadaie MR, Doniger J, Hung CL, Pantazis P. 9-nitrocamptothecin selectively inhibits human immunodeficiency virus type 1 replication in freshly infected parental but not 9-nitrocamptothecin-resistant U937 monocytoid cells. AIDS Res Hum Retroviruses 1999; 15:239-45. [PMID: 10052754 DOI: 10.1089/088922299311411] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We have previously reported that 9-nitrocamptothecin (9NC) inhibited human immunodeficiency type 1 (HIV-1) replication in latently HIV-1-infected T lymphocytic ACH-2 cells stimulated with the cytokine tumor necrosis factor alpha (TNF-alpha) (Moulton et al., AIDS Res Hum Retroviruses 1998;14:39). 9NC induced an accelerated apoptosis in HIV-1-infected, but not uninfected, lymphocytic cells. The present study demonstrates that 9NC selectively inhibits release of HIV-1 from freshly infected monocytoid U937 cells in a dose-response manner. Significant inhibition was achieved with concentrations of 9NC that were not toxic. In contrast, HIV-1 replication in 9NC-resistant monocytoid cells, derived from U937, was not inhibited by similar doses of 9NC. Importantly, sensitivity of HIV-1 replication to 9NC correlated with the effect of 9NC on topoisomerase I (topo I) activity. In a 9NC-sensitive subline, 9NC induced posttranslational activation of the nuclear transcription factor kappaB (NF-kappaB) after the drug treatment. This activation was neither related to selective 9NC suppression of HIV-1 replication, nor was it sufficient for the 9NC-induced toxicity in the drug-sensitive monocytoid cells. Taken together, the selective inhibition of HIV-1 replication in both lymphoid and monocytoid cells lends further credence to the potential development of 9NC as an alternative drug for treating HIV-1 infection.
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Affiliation(s)
- M R Sadaie
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20007, USA
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Pommier Y, Pourquier P, Fan Y, Strumberg D. Mechanism of action of eukaryotic DNA topoisomerase I and drugs targeted to the enzyme. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1400:83-105. [PMID: 9748515 DOI: 10.1016/s0167-4781(98)00129-8] [Citation(s) in RCA: 422] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
DNA topoisomerase I is essential for cellular metabolism and survival. It is also the target of a novel class of anticancer drugs active against previously refractory solid tumors, the camptothecins. The present review describes the topoisomerase I catalytic mechanisms with particular emphasis on the cleavage complex that represents the enzyme's catalytic intermediate and the site of action for camptothecins. Roles of topoisomerase I in DNA replication, transcription and recombination are also reviewed. Because of the importance of topoisomerase I as a chemotherapeutic target, we review the mechanisms of action of camptothecins and the other topoisomerase I inhibitors identified to date.
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Affiliation(s)
- Y Pommier
- Laboratory of Molecular Pharmacology, Division of Basic Sciences, National Cancer Institute, Bethesda, MD 20892-4255, USA.
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Abstract
The present review first describes the different type I topoisomerases found in eukaryotic cells: nuclear topoisomerase I (top1), topoisomerase 3 (top3), mitochondrial topoisomerase I and viral topoisomerases I. The second part of the review provides extensive information on the topoisomerase I inhibitors identified to date. These drugs can be grouped in two categories: top1 poisons and top1 suppressors. Both inhibit enzyme catalytic activity but top1 poisons trap the top1 catalytic intermediates ('cleavage complexes') while top1 suppressors prevent or reverse top1 cleavage complexes. The molecular interactions of camptothecin with the top1 cleavage complexes are discussed as well as the mechanisms of selective killing of cancer cells.
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Affiliation(s)
- Y Pommier
- Laboratory of Molecular Pharmacology, National Cancer Institute, Bethesda, MD 20892-4255, USA
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Moulton S, Pantazis P, Epstein JS, Sadaie MR. 9-Nitrocamptothecin inhibits tumor recrosis factor-mediated activation of human immunodeficiency virus type 1 and enhances apoptosis in a latently infected T cell clone. AIDS Res Hum Retroviruses 1998; 14:39-49. [PMID: 9453250 DOI: 10.1089/aid.1998.14.39] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Transition from latency to active replication is a crucial stage for the process of human immunodeficiency virus type 1 (HIV-1) infection and life cycle. HIV-1 replication in latently infected cells can be strongly induced by the cytokine tumor necrosis factor alpha (TNF-alpha) and the proliferation-arresting chemical sodium butyrate (NaB). We have investigated the ability of the drug 9-nitrocamptothecin (9NC), a potent cellular topoisomerase I (topo I) inhibitor currently in clinical trials in cancer patients, to regulate HIV-1 replication in latently infected lymphocytic ACH-2 cells on reactivation with either TNF-alpha or NaB. Treatment of ACH-2 cells with 9NC alone resulted in increased levels of viral transcripts, while there was a slight reduction or no change in the levels of host cell transcripts. However, pretreatment of ACH-2 cells with 9NC inhibited TNF-alpha-induced extracellular HIV-1 p24 levels up to approximately 95% and nearly 80% of the cell-associated viral RNAs. The quantitative decrease in viral products was concomitant with a decrease in cellular gene expression and induction of apoptosis in the host cells. 9NC blocked the infected cells at the boundary of the S and G2 phases, resulting in an accelerated apoptosis that was further enhanced with TNF-alpha treatment. Similar results were observed following concurrent exposure to TNF-alpha and 9NC, but 9NC failed to inhibit upregulation of HIV-1 mRNA in ACH-2 cells exposed to TNF-alpha before 9NC treatment. Further, 9NC had no inhibitory effect on NaB-induced apoptosis and upregulation of HIV-1 mRNA expression regardless of whether 9NC and NaB were used concurrently or in various treatment sequences. In uninfected lymphocytic CEM cells derived from a common parental cell line, a slight downregulation of cellular gene expression was detected along with low-level apoptosis. These results demonstrate that 9NC impairs TNF-alpha-induced, but not NaB-induced, HIV-1 activation, and suggest a means of inhibiting active HIV-1 viremia arising as a result of elevated TNF-alpha levels.
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Affiliation(s)
- S Moulton
- Division of Transfusion Transmitted Diseases, CBER/Food and Drug Administration, Rockville, Maryland 20852-1448, USA
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Harrich D, Ulich C, García-Martínez LF, Gaynor RB. Tat is required for efficient HIV-1 reverse transcription. EMBO J 1997; 16:1224-35. [PMID: 9135139 PMCID: PMC1169721 DOI: 10.1093/emboj/16.6.1224] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The ability of human immunodeficiency virus-1 (HIV-1) to undergo efficient reverse transcription is dependent on a number of parameters. These include the binding of the tRNA(3)(Lys) to the HIV-1 primer binding site and the subsequent interaction with the heterodimeric reverse transcriptase. Recently, we demonstrated that TAR RNA was also necessary for efficient HIV-1 reverse transcription. Given the fact that the Tat protein is involved in the activation of HIV-1 gene expression in conjunction with TAR, we wished to determine whether Tat might also be involved in the control of HIV-1 reverse transcription. HIV-1 virions deleted in the tat gene were unable to initiate reverse transcription efficiently upon infection of peripheral blood mononuclear cells (PBMCs). This defect was not due to decreased amounts of genomic RNA, reverse transcriptase or other HIV-1 proteins which were incorporated into the virion. Following transfection of wild-type but not mutant tat genes into cell lines producing HIV-1 lacking tat, the virions produced could be complemented for defects in reverse transcription upon subsequent infection of PBMCs. In contrast, the defect in reverse transcription seen with HIV-1 lacking the tat gene could not be complemented when the target cells rather than the producer cells contained tat. Viruses lacking tat were also defective in endogenous assays of reverse transcription, although these viruses contained similar levels of reverse transcriptase. These results indicate that the Tat protein, in addition to regulating the level of gene expression, is also important for efficient HIV-1 reverse transcription.
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Affiliation(s)
- D Harrich
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8594, USA
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Abstract
The plant alkaloid camptothecin (CPT) has demonstrated the ability to inhibit replication of the equine anemia virus (E1AV) and the human immunodeficiency virus (HIV) in infected cells in culture. Further, CPT prevented the development of lymphoma and erythroleukemia in mice infected with the Moloney murine leukemia virus and the Friend erythroleukemia virus, respectively, as assessed by prevention or reduction of splenomegaly. These results were observed at concentrations that had no apparent toxic effects on the mice. It has been suggested that the antiretroviral activity of CPT is mediated by the host cell's enzyme topoisomerase I. Taken collectively, the findings indicate that CPT analogues may develop into potent drugs against various human and animal diseases caused by diverse retroviruses. Copyright 1996 S. Karger AG, Basel
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Affiliation(s)
- P. Pantazis
- The Stehlin Foundation for Cancer Research at St. Joseph Hospital, Houston, Tex., USA
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Kuwana M, Medsger TA, Wright TM. T cell proliferative response induced by DNA topoisomerase I in patients with systemic sclerosis and healthy donors. J Clin Invest 1995; 96:586-96. [PMID: 7615831 PMCID: PMC185233 DOI: 10.1172/jci118071] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The in vitro T cell proliferative response to DNA topoisomerase I (topo I) was examined in 26 systemic sclerosis (SSc) patients with anti-topo I antibody, 10 SSc patients without anti-topo I antibody, and 21 healthy donors. Using recombinant fusion proteins encompassing the entire human topo I amino acid sequence, a topo I-specific proliferative response was detected in PBMC cultures from 25 (96%) anti-topo I-positive SSc patients, 4 (40%) anti-topo I-negative SSc patients, and 13 (62%) healthy donors. Molecular typing at MHC class II loci revealed that all SSc patients and healthy donors having either DRB1*1501,2 (DR15), DRB1*1101,3,4 (DR11), or DRB1*07 (DR7) were responders. Characterization of the topo I-induced T cell proliferative response showed that (a) the responding cells were CD4+ T cells; (b) antigen-presenting cells were necessary for the response; (c) the response was restricted by HLA-DR, and to a lesser extent by HLA-DQ; and (d) the estimated frequency of the responding T cells determined by limiting dilution analysis was 1/9,277-1/24,853. PBMC cultures from anti-topo I-positive SSc patients showed a high T cell proliferative response after only 3 d of culture with topo I. Anti-topo I-negative SSc patients and healthy donors had no proliferative response after 3 d, but did respond after 7 d of culture. T cell proliferative responses to six truncated topo I fragments tested individually showed different patterns of T cell proliferation that were dependent upon the responder's HLA-DR alleles. These results indicate that T cells reactive with topo I are components of the normal T cell repertoire, and that the topo I-specific T cell proliferative response is not associated with the presence or absence of SSc or anti-topo I antibody, but is restricted by MHC class II alleles.
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Affiliation(s)
- M Kuwana
- Department of Medicine, University of Pittsburgh School of Medicine, Pennsylvania 15261, USA
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