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Ikeda T, Shimizu R, Nasser H, Carpenter MA, Cheng AZ, Brown WL, Sauter D, Harris RS. APOBEC3 degradation is the primary function of HIV-1 Vif determining virion infectivity in the myeloid cell line THP-1. mBio 2023; 14:e0078223. [PMID: 37555667 PMCID: PMC10470580 DOI: 10.1128/mbio.00782-23] [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] [Received: 03/28/2023] [Accepted: 06/22/2023] [Indexed: 08/10/2023] Open
Abstract
HIV-1 must overcome multiple innate antiviral mechanisms to replicate in CD4+ T lymphocytes and macrophages. Previous studies have demonstrated that the apolipoprotein B mRNA editing enzyme polypeptide-like 3 (APOBEC3, A3) family of proteins (at least A3D, A3F, A3G, and stable A3H haplotypes) contribute to HIV-1 restriction in CD4+ T lymphocytes. Virus-encoded virion infectivity factor (Vif) counteracts this antiviral activity by degrading A3 enzymes allowing HIV-1 replication in infected cells. In addition to A3 proteins, Vif also targets other cellular proteins in CD4+ T lymphocytes, including PPP2R5 proteins. However, whether Vif primarily degrades only A3 proteins during viral replication is currently unknown. Herein, we describe the development and characterization of A3F-, A3F/A3G-, and A3A-to-A3G-null THP-1 cells. In comparison to Vif-proficient HIV-1, Vif-deficient viruses have substantially reduced infectivity in parental and A3F-null THP-1 cells, and a more modest decrease in infectivity in A3F/A3G-null cells. Remarkably, disruption of A3A-A3G protein expression completely restores the infectivity of Vif-deficient viruses in THP-1 cells. These results indicate that the primary function of Vif during infectious HIV-1 production from THP-1 cells is the targeting and degradation of A3 enzymes. IMPORTANCE HIV-1 Vif neutralizes the HIV-1 restriction activity of A3 proteins. However, it is currently unclear whether Vif has additional essential cellular targets. To address this question, we disrupted A3A to A3G genes in the THP-1 myeloid cell line using CRISPR and compared the infectivity of wild-type HIV-1 and Vif mutants with the selective A3 neutralization activities. Our results demonstrate that the infectivity of Vif-deficient HIV-1 and the other Vif mutants is fully restored by ablating the expression of cellular A3A to A3G proteins. These results indicate that A3 proteins are the only essential target of Vif that is required for fully infectious HIV-1 production from THP-1 cells.
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Affiliation(s)
- Terumasa Ikeda
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Ryo Shimizu
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
- Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Hesham Nasser
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
- Department of Clinical Pathology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Michael A. Carpenter
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas, USA
| | - Adam Z. Cheng
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA
| | - William L. Brown
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Daniel Sauter
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Reuben S. Harris
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas, USA
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2
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Ikeda T, Shimizu R, Nasser H, Carpenter MA, Cheng AZ, Brown WL, Sauter D, Harris RS. APOBEC3 degradation is the primary function of HIV-1 Vif for virus replication in the myeloid cell line THP-1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534666. [PMID: 37034786 PMCID: PMC10081227 DOI: 10.1101/2023.03.28.534666] [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: 06/19/2023]
Abstract
HIV-1 must overcome multiple innate antiviral mechanisms to replicate in CD4 + T lymphocytes and macrophages. Previous studies have demonstrated that the APOBEC3 (A3) family of proteins (at least A3D, A3F, A3G, and stable A3H haplotypes) contribute to HIV-1 restriction in CD4 + T lymphocytes. Virus-encoded virion infectivity factor (Vif) counteracts this antiviral activity by degrading A3 enzymes allowing HIV-1 replication in infected cells. In addition to A3 proteins, Vif also targets other cellular proteins in CD4 + T lymphocytes, including PPP2R5 proteins. However, whether Vif primarily degrades only A3 proteins or has additional essential targets during viral replication is currently unknown. Herein, we describe the development and characterization of A3F -, A3F/A3G -, and A3A -to- A3G -null THP-1 cells. In comparison to Vif-proficient HIV-1, Vif-deficient viruses have substantially reduced infectivity in parental and A3F -null THP-1 cells, and a more modest decrease in infectivity in A3F/A3G -null cells. Remarkably, disruption of A3Aâ€"A3G protein expression completely restores the infectivity of Vif-deficient viruses in THP-1 cells. These results indicate that the primary function of Vif during HIV-1 replication in THP-1 cells is the targeting and degradation of A3 enzymes. Importance HIV-1 Vif neutralizes the HIV-1 restriction activity of A3 proteins. However, it is currently unclear whether Vif has additional essential cellular targets. To address this question, we disrupted A3A to A3G genes in the THP-1 myeloid cell line using CRISPR and compared the infectivity of wildtype HIV-1 and Vif mutants with the selective A3 neutralization activities. Our results demonstrate that the infectivity of Vif-deficient HIV-1 and the other Vif mutants is fully restored by ablating the expression of cellular A3A to A3G proteins. These results indicate that A3 proteins are the only essential target of Vif that is required for HIV-1 replication in THP-1 cells.
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Affiliation(s)
- Terumasa Ikeda
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 8600811, Japan
| | - Ryo Shimizu
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 8600811, Japan
- Graduate School of Medical Sciences, Kumamoto University, Kumamoto 8600811, Japan
| | - Hesham Nasser
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto 8600811, Japan
- Department of Clinical Pathology, Faculty of Medicine, Suez Canal University, Ismailia 41511, Egypt
| | - Michael A. Carpenter
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
| | - Adam Z. Cheng
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - William L. Brown
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Daniel Sauter
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen 72076, Germany
| | - Reuben S. Harris
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, Texas 78229, USA
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3
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Shilova ON, Tsyba DL, Shilov ES. Mutagenic Activity of AID/APOBEC Deaminases in Antiviral Defense and Carcinogenesis. Mol Biol 2022; 56:46-58. [PMID: 35194245 PMCID: PMC8852905 DOI: 10.1134/s002689332201006x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/23/2021] [Accepted: 06/01/2021] [Indexed: 01/02/2023]
Abstract
Proteins of the AID/APOBEC family are capable of cytidine deamination in nucleic acids forming uracil. These enzymes are involved in mRNA editing, protection against viruses, the introduction of point mutations into DNA during somatic hypermutation, and antibody isotype switching. Since these deaminases, especially AID, are potent mutagens, their expression, activity, and specificity are regulated by several intracellular mechanisms. In this review, we discuss the mechanisms of impaired expression and activation of AID/APOBEC proteins in human tumors and their role in carcinogenesis and tumor progression. Also, the diagnostic and potential therapeutic value of increased expression of AID/APOBEC in different types of tumors is analyzed. We assume that in the case of solid tumors, increased expression of endogenous deaminases can serve as a marker of response to immunotherapy since multiple point mutations in host DNA could lead to amino acid substitutions in tumor proteins and thereby increase the frequency of neoepitopes.
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Affiliation(s)
- O. N. Shilova
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia
| | - D. L. Tsyba
- Pavlov First State Medical University, 197022 St. Petersburg, Russia
- Sirius University of Science and Technology, 354340 Sochi, Russia
| | - E. S. Shilov
- Faculty of Biology, Moscow State University, 119234 Moscow, Russia
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Differential Activity of APOBEC3F, APOBEC3G, and APOBEC3H in the Restriction of HIV-2. J Mol Biol 2022; 434:167355. [PMID: 34774569 PMCID: PMC8752514 DOI: 10.1016/j.jmb.2021.167355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 11/04/2021] [Accepted: 11/04/2021] [Indexed: 02/01/2023]
Abstract
Human immunodeficiency virus (HIV) mutagenesis is driven by a variety of internal and external sources, including the host APOBEC3 (apolipoprotein B mRNA editing enzyme catalytic polypetide-like 3; A3) family of mutagenesis factors, which catalyze G-to-A transition mutations during virus replication. HIV-2 replication is characterized by a relative lack of G-to-A mutations, suggesting infrequent mutagenesis by A3 proteins. To date, the activity of the A3 repertoire against HIV-2 has remained largely uncharacterized, and the mutagenic activity of these proteins against HIV-2 remains to be elucidated. In this study, we provide the first comprehensive characterization of the restrictive capacity of A3 proteins against HIV-2 in cell culture using a dual fluorescent reporter HIV-2 vector virus. We found that A3F, A3G, and A3H restricted HIV-2 infectivity in the absence of Vif and were associated with significant increases in the frequency of viral mutants. These proteins increased the frequency of G-to-A mutations within the proviruses of infected cells as well. A3G and A3H also reduced HIV-2 infectivity via inhibition of reverse transcription and the accumulation of DNA products during replication. In contrast, A3D did not exhibit any restrictive activity against HIV-2, even at higher expression levels. Taken together, these results provide evidence that A3F, A3G, and A3H, but not A3D, are capable of HIV-2 restriction. Differences in A3-mediated restriction of HIV-1 and HIV-2 may serve to provide new insights in the observed mutation profiles of these viruses.
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Shi M, Tan L, Zhang Y, Meng C, Wang W, Sun Y, Song C, Liu W, Liao Y, Yu S, Ren T, Ding Z, Liu X, Qiu X, Ding C. Characterization and functional analysis of chicken APOBEC4. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 106:103631. [PMID: 31991164 DOI: 10.1016/j.dci.2020.103631] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/21/2020] [Accepted: 01/21/2020] [Indexed: 06/10/2023]
Abstract
The APOBEC proteins play significant roles in the innate and adaptive immune system, probably due to their deaminase activities. Because APOBEC1 (A1) and APOBEC3 (A3) are absent in the chicken genome, we were interested in determining whether chicken APOBEC4 (A4) possessed more complex functions than its mammalian homologs. In this study, chicken A4 (chA4) mRNA was identified and cloned for the first time. Based on bioinformatics analyses, the conserved zinc-coordinating motif (HXE … PC(X)2-6C) was identified on the surface of chA4 and contained highly conserved His97, Glu99, Pro130, Cys131 and Cys138 active sites. The highest expression levels of constitutive chA4 were detected in primary lymphocytes and bursa of Fabricius. Newcastle Disease (ND) is one of the most serious infectious diseases in birds, causing major economic losses to the poultry industry. In vitro, Newcastle Disease Virus (NDV) early infection induced significant increases in chA4 expression in the chicken B cell line, DT40, the macrophage cell line, HD11 and the CD4+ T cell line, MSB-1, but not the fibroblast cell line, DF-1. In vivo, the expression levels of chA4 were up-regulated in several tissues from NDV-infected chickens, especially the thymus, testicles, duodenum and kidney. The high level expression of exogenous chA4 displayed inhibitory effects on NDV and reduced viral RNA in infected cells. Taken together, these data demonstrate that chA4 is involved in the chicken immune system and may play important roles in host anti-viral responses.
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Affiliation(s)
- Mengyu Shi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Lei Tan
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Yaodan Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Chunchun Meng
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Wei Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Yingjie Sun
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Cuiping Song
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Weiwei Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Ying Liao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Tao Ren
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, People's Republic of China.
| | - Zhuang Ding
- Laboratory of Infectious Diseases, College of Veterinary Medicine, Jilin University, Changchun, 130062, PR China.
| | - Xiufan Liu
- Key Laboratory of Animal Infectious Diseases, Yangzhou University, Yangzhou, 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, PR China.
| | - Xusheng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China.
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, PR China.
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6
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Zotova AA, Atemasova AA, Filatov AV, Mazurov DV. HIV Restriction Factors and Their Ambiguous Role during Infection. Mol Biol 2019. [DOI: 10.1134/s0026893319020171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Anderson BD, Ikeda T, Moghadasi SA, Martin AS, Brown WL, Harris RS. Natural APOBEC3C variants can elicit differential HIV-1 restriction activity. Retrovirology 2018; 15:78. [PMID: 30558640 PMCID: PMC6297987 DOI: 10.1186/s12977-018-0459-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 12/06/2018] [Indexed: 01/29/2023] Open
Abstract
Background The APOBEC3 (A3) family of DNA cytosine deaminases provides an innate barrier to infection by retroviruses including HIV-1. A total of five enzymes, A3C, A3D, A3F, A3G and A3H, are degraded by the viral accessory protein Vif and expressed at high levels in CD4+ T cells, the primary reservoir for HIV-1 replication in vivo. Apart from A3C, all of these enzymes mediate restriction of Vif-deficient HIV-1. However, a rare variant of human A3C (Ile188) was shown recently to restrict Vif-deficient HIV-1 in a 293T-based single cycle infection system. The potential activity of this naturally occurring A3C variant has yet to be characterized in a T cell-based spreading infection system. Here we employ a combination of Cas9/gRNA disruption and transient and stable protein expression to assess the roles of major Ser188 and minor Ile188 A3C variants in HIV-1 restriction in T cell lines. Results Cas9-mediated mutation of endogenous A3C in the non-permissive CEM2n T cell line did not alter HIV-1 replication kinetics, and complementation with A3C-Ser188 or A3C-Ile188 was similarly aphenotypic. Stable expression of A3C-Ser188 in the permissive T cell line SupT11 also had little effect. However, stable expression of A3C-Ile188 in SupT11 cells inhibited Vif-deficient virus replication and inflicted G-to-A mutations. Conclusions A3C-Ile188 is capable of inhibiting Vif-deficient HIV-1 replication in T cells. Although A3C is eclipsed by the dominant anti-viral activities of other A3s in non-permissive T cell lines and primary T lymphocytes, this enzyme may still be able to contribute to HIV-1 diversification in vivo. Our results highlight the functional redundancy in the human A3 family with regards to HIV-1 restriction and the need to consider naturally occurring variants.
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Affiliation(s)
- Brett D Anderson
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, Center for Genome Engineering, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
| | - Terumasa Ikeda
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, Center for Genome Engineering, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA.,Howard Hughes Medical Institute, University of Minnesota, 2231 6th St. S.E., Minneapolis, MN, 55455, USA
| | - Seyed Arad Moghadasi
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, Center for Genome Engineering, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
| | - Amber St Martin
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, Center for Genome Engineering, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
| | - William L Brown
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, Center for Genome Engineering, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, Center for Genome Engineering, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN, USA. .,Howard Hughes Medical Institute, University of Minnesota, 2231 6th St. S.E., Minneapolis, MN, 55455, USA.
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8
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Milewska A, Kindler E, Vkovski P, Zeglen S, Ochman M, Thiel V, Rajfur Z, Pyrc K. APOBEC3-mediated restriction of RNA virus replication. Sci Rep 2018; 8:5960. [PMID: 29654310 PMCID: PMC5899082 DOI: 10.1038/s41598-018-24448-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/04/2018] [Indexed: 01/13/2023] Open
Abstract
APOBEC3 family members are cytidine deaminases with roles in intrinsic responses to infection by retroviruses and retrotransposons, and in the control of other DNA viruses, such as herpesviruses, parvoviruses and hepatitis B virus. Although effects of APOBEC3 members on viral DNA have been demonstrated, it is not known whether they edit RNA genomes through cytidine deamination. Here, we investigated APOBEC3-mediated restriction of Coronaviridae. In experiments in vitro, three human APOBEC3 proteins (A3C, A3F and A3H) inhibited HCoV-NL63 infection and limited production of progeny virus, but did not cause hypermutation of the coronaviral genome. APOBEC3-mediated restriction was partially dependent on enzyme activity, and was reduced by the use of enzymatically inactive APOBEC3. Moreover, APOBEC3 proteins bound to the coronaviral nucleoprotein, and this interaction also affected viral replication. Although the precise molecular mechanism of deaminase-dependent inhibition of coronavirus replication remains elusive, our results further our understanding of APOBEC-mediated restriction of RNA virus infections.
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Affiliation(s)
- Aleksandra Milewska
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland.
- Virogenetics Laboratory of Virology, Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7a, 30-387, Krakow, Poland.
| | - Eveline Kindler
- Institute for Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, Switzerland
| | - Philip Vkovski
- Institute for Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Slawomir Zeglen
- Department of Cardiac Surgery and Transplantology, Silesian Center for Heart Diseases, Marii Curie-Skłodowskiej 9, 41-800, Zabrze, Poland
- Head of Histology Department, Medical Department, University of Opole, Opole, Poland
| | - Marek Ochman
- Department of Pharmacology, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia in Katowice, Katowice, Poland
| | - Volker Thiel
- Institute for Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, Bern, Switzerland
| | - Zenon Rajfur
- Institute of Physics, Faculty of Physics, Astronomy and Applied Computer Sciences, Jagiellonian University, Lojasiewicza 11, 30-348, Krakow, Poland
| | - Krzysztof Pyrc
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland.
- Virogenetics Laboratory of Virology, Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7a, 30-387, Krakow, Poland.
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9
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Ikeda T, Symeonides M, Albin JS, Li M, Thali M, Harris RS. HIV-1 adaptation studies reveal a novel Env-mediated homeostasis mechanism for evading lethal hypermutation by APOBEC3G. PLoS Pathog 2018; 14:e1007010. [PMID: 29677220 PMCID: PMC5931688 DOI: 10.1371/journal.ppat.1007010] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 05/02/2018] [Accepted: 04/09/2018] [Indexed: 02/07/2023] Open
Abstract
HIV-1 replication normally requires Vif-mediated neutralization of APOBEC3 antiviral enzymes. Viruses lacking Vif succumb to deamination-dependent and -independent restriction processes. Here, HIV-1 adaptation studies were leveraged to ask whether viruses with an irreparable vif deletion could develop resistance to restrictive levels of APOBEC3G. Several resistant viruses were recovered with multiple amino acid substitutions in Env, and these changes alone are sufficient to protect Vif-null viruses from APOBEC3G-dependent restriction in T cell lines. Env adaptations cause decreased fusogenicity, which results in higher levels of Gag-Pol packaging. Increased concentrations of packaged Pol in turn enable faster virus DNA replication and protection from APOBEC3G-mediated hypermutation of viral replication intermediates. Taken together, these studies reveal that a moderate decrease in one essential viral activity, namely Env-mediated fusogenicity, enables the virus to change other activities, here, Gag-Pol packaging during particle production, and thereby escape restriction by the antiviral factor APOBEC3G. We propose a new paradigm in which alterations in viral homeostasis, through compensatory small changes, constitute a general mechanism used by HIV-1 and other viral pathogens to escape innate antiviral responses and other inhibitions including antiviral drugs.
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Affiliation(s)
- Terumasa Ikeda
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, United States of America
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Menelaos Symeonides
- Cellular, Molecular and Biomedical Sciences Graduate Program and Department of Microbiology and Molecular Genetics, Larner College of Medicine and College of Agriculture and Life Sciences, University of Vermont, Burlington, Vermont, United States of America
| | - John S. Albin
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Ming Li
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Markus Thali
- Cellular, Molecular and Biomedical Sciences Graduate Program and Department of Microbiology and Molecular Genetics, Larner College of Medicine and College of Agriculture and Life Sciences, University of Vermont, Burlington, Vermont, United States of America
| | - Reuben S. Harris
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, United States of America
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, Minnesota, United States of America
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10
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Multiple Inhibitory Factors Act in the Late Phase of HIV-1 Replication: a Systematic Review of the Literature. Microbiol Mol Biol Rev 2018; 82:82/1/e00051-17. [PMID: 29321222 DOI: 10.1128/mmbr.00051-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The use of lentiviral vectors for therapeutic purposes has shown promising results in clinical trials. The ability to produce a clinical-grade vector at high yields remains a critical issue. One possible obstacle could be cellular factors known to inhibit human immunodeficiency virus (HIV). To date, five HIV restriction factors have been identified, although it is likely that more factors are involved in the complex HIV-cell interaction. Inhibitory factors that have an adverse effect but do not abolish virus production are much less well described. Therefore, a gap exists in the knowledge of inhibitory factors acting late in the HIV life cycle (from transcription to infection of a new cell), which are relevant to the lentiviral vector production process. The objective was to review the HIV literature to identify cellular factors previously implicated as inhibitors of the late stages of lentivirus production. A search for publications was conducted on MEDLINE via the PubMed interface, using the keyword sequence "HIV restriction factor" or "HIV restriction" or "inhibit HIV" or "repress HIV" or "restrict HIV" or "suppress HIV" or "block HIV," with a publication date up to 31 December 2016. Cited papers from the identified records were investigated, and additional database searches were performed. A total of 260 candidate inhibitory factors were identified. These factors have been identified in the literature as having a negative impact on HIV replication. This study identified hundreds of candidate inhibitory factors for which the impact of modulating their expression in lentiviral vector production could be beneficial.
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11
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Wan L, Nagata T, Katahira M. Influence of the DNA sequence/length and pH on deaminase activity, as well as the roles of the amino acid residues around the catalytic center of APOBEC3F. Phys Chem Chem Phys 2018; 20:3109-3117. [DOI: 10.1039/c7cp04477a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The roles of the amino acid residues responsible for the deaminase activity of APOBEC3F were identified by mutation analysis.
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Affiliation(s)
- Li Wan
- Institute of Advanced Energy
- Kyoto University
- Uji
- Japan
- Graduate School of Energy Science
| | - Takashi Nagata
- Institute of Advanced Energy
- Kyoto University
- Uji
- Japan
- Graduate School of Energy Science
| | - Masato Katahira
- Institute of Advanced Energy
- Kyoto University
- Uji
- Japan
- Graduate School of Energy Science
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12
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Jaguva Vasudevan AA, Hofmann H, Willbold D, Häussinger D, Koenig BW, Münk C. Enhancing the Catalytic Deamination Activity of APOBEC3C Is Insufficient to Inhibit Vif-Deficient HIV-1. J Mol Biol 2017; 429:1171-1191. [DOI: 10.1016/j.jmb.2017.03.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/08/2017] [Accepted: 03/08/2017] [Indexed: 12/17/2022]
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13
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Miyagi E, Kao S, Fumitaka M, Buckler-White A, Plishka R, Strebel K. Long-term passage of Vif-null HIV-1 in CD4 + T cells expressing sub-lethal levels of APOBEC proteins fails to develop APOBEC resistance. Virology 2017; 504:1-11. [PMID: 28131088 DOI: 10.1016/j.virol.2017.01.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 01/19/2017] [Accepted: 01/21/2017] [Indexed: 10/20/2022]
Abstract
APOBEC3G (A3G) is a cytidine deaminase with potent antiviral activity that is antagonized by Vif. A3G is expressed in a cell type-specific manner and some semi-permissive cells, including A3.01, express A3G but fail to block replication of Vif-null HIV-1. Here we explored the semi-permissive nature of A3.01 cells and found it to be defined exclusively by the levels of A3G. Indeed, minor changes in A3G levels rendered A3.01 cells either fully permissive or non-permissive for Vif-null HIV-1. Our data indicate that A3.01 cells express sub-lethal levels of catalytically active A3G that affects Vif-null HIV-1 at the proviral level but does not completely block virus replication due to purifying selection. Attempts to use the selective pressure exerted by such sub-lethal levels of A3G to select for APOBEC-resistant Vif-null virus capable of replicating in H9 cells failed despite passaging virus for five months, demonstrating that Vif is a critical viral accessory protein.
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Affiliation(s)
- Eri Miyagi
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 4, Room 312, 4 Center Drive, MSC 0460, Bethesda, MD 20892, United States
| | - Sandra Kao
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 4, Room 312, 4 Center Drive, MSC 0460, Bethesda, MD 20892, United States
| | - Miyoshi Fumitaka
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 4, Room 312, 4 Center Drive, MSC 0460, Bethesda, MD 20892, United States
| | - Alicia Buckler-White
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 4, Room 312, 4 Center Drive, MSC 0460, Bethesda, MD 20892, United States
| | - Ron Plishka
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 4, Room 312, 4 Center Drive, MSC 0460, Bethesda, MD 20892, United States
| | - Klaus Strebel
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg. 4, Room 312, 4 Center Drive, MSC 0460, Bethesda, MD 20892, United States.
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14
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Shaban NM, Shi K, Li M, Aihara H, Harris RS. 1.92 Angstrom Zinc-Free APOBEC3F Catalytic Domain Crystal Structure. J Mol Biol 2016; 428:2307-2316. [PMID: 27139641 PMCID: PMC5142242 DOI: 10.1016/j.jmb.2016.04.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/13/2016] [Accepted: 04/19/2016] [Indexed: 01/07/2023]
Abstract
The APOBEC3 family of DNA cytosine deaminases is capable of restricting the replication of HIV-1 and other pathogens. Here, we report a 1.92 Å resolution crystal structure of the Vif-binding and catalytic domain of APOBEC3F (A3F). This structure is distinct from the previously published APOBEC and phylogenetically related deaminase structures, as it is the first without zinc in the active site. We determined an additional structure containing zinc in the same crystal form that allows direct comparison with the zinc-free structure. In the absence of zinc, the conserved active site residues that normally participate in zinc coordination show unique conformations, including a 90 degree rotation of His249 and disulfide bond formation between Cys280 and Cys283. We found that zinc coordination is influenced by pH, and treating the protein at low pH in crystallization buffer is sufficient to remove zinc. Zinc coordination and catalytic activity are reconstituted with the addition of zinc only in a reduced environment likely due to the two active site cysteines readily forming a disulfide bond when not coordinating zinc. We show that the enzyme is active in the presence of zinc and cobalt but not with other divalent metals. These results unexpectedly demonstrate that zinc is not required for the structural integrity of A3F and suggest that metal coordination may be a strategy for regulating the activity of A3F and related deaminases.
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Affiliation(s)
- Nadine M. Shaban
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455,Correspondence: ;
| | - Ke Shi
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455
| | - Ming Li
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455
| | - Reuben S. Harris
- Department of Biochemistry, Molecular Biology, and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, University of Minnesota, Minneapolis, MN 55455,Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN 55455,Correspondence: ;
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15
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APOBEC3G and APOBEC3F Act in Concert To Extinguish HIV-1 Replication. J Virol 2016; 90:4681-4695. [PMID: 26912618 DOI: 10.1128/jvi.03275-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2016] [Accepted: 02/18/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The multifunctional HIV-1 accessory protein Vif counters the antiviral activities of APOBEC3G (A3G) and APOBEC3F (A3F), and some Vifs counter stable alleles of APOBEC3H (A3H). Studies in humanized mice have shown that HIV-1 lacking Vif expression is not viable. Here, we look at the relative contributions of the three APOBEC3s to viral extinction. Inoculation of bone marrow/liver/thymus (BLT) mice with CCR5-tropic HIV-1JRCSF(JRCSF) expressing a vif gene inactive for A3G but not A3F degradation activity (JRCSFvifH42/43D) displayed either no or delayed replication. JRCSF expressing a vif gene mutated to inactivate A3F degradation but not A3G degradation (JRCSFvifW79S) always replicated to high viral loads with variable delays. JRCSF with vif mutated to lack both A3G and A3F degradation activities (JRCSFvifH42/43DW79S) failed to replicate, mimicking JRCSF without Vif expression (JRCSFΔvif). JRCSF and JRCSFvifH42/43D, but not JRCSFvifW79S or JRCSFvifH42/43DW79S, degraded APOBEC3D. With one exception, JRCSFs expressing mutant Vifs that replicated acquired enforced vif mutations. These mutations partially restored A3G or A3F degradation activity and fully replaced JRCSFvifH42/43D or JRCSFvifW79S by 10 weeks. Surprisingly, induced mutations temporally lagged behind high levels of virus in blood. In the exceptional case, JRCSFvifH42/43D replicated after a prolonged delay with no mutations in vif but instead a V27I mutation in the RNase H coding sequence. JRCSFvifH42/43D infections exhibited massive GG/AG mutations in pol viral DNA, but in viral RNA, there were no fixed mutations in the Gag or reverse transcriptase coding sequence. A3H did not contribute to viral extinction but, in combination with A3F, could delay JRCSF replication. A3H was also found to hypermutate viral DNA. IMPORTANCE Vif degradation of A3G and A3F enhances viral fitness, as virus with even a partially restored capacity for degradation outgrows JRCSFvifH42/43D and JRCSFvifW79S. Unexpectedly, fixation of mutations that replaced H42/43D or W79S in viral RNA lagged behind the appearance of high viral loads. In one exceptional JRCSFvifH42/43D infection, vif was unchanged but replication proceeded after a long delay. These results suggest that Vif binds and inhibits the non-cytosine deaminase activities of intact A3G and intact A3F, allowing JRCSFvifH42/43D and JRCSFvifW79S to replicate with reduced fitness. Subsequently, enhanced Vif function is acquired by enforced mutations. In infected cells, JRCSFΔvif and JRCSFvifH42/43DW79S are exposed to active A3F and A3G and fail to replicate. JRCSFvifH42/43D Vif degrades A3F and, in some cases, overcomes A3G mutagenic activity to replicate. Vif may have evolved to inhibit A3F and A3G by stoichiometric binding and subsequently acquired the ability to target these proteins to proteasomes.
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16
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Chen Q, Xiao X, Wolfe A, Chen XS. The in vitro Biochemical Characterization of an HIV-1 Restriction Factor APOBEC3F: Importance of Loop 7 on Both CD1 and CD2 for DNA Binding and Deamination. J Mol Biol 2016; 428:2661-70. [PMID: 27063502 DOI: 10.1016/j.jmb.2016.03.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/27/2016] [Accepted: 03/28/2016] [Indexed: 10/22/2022]
Abstract
APOBEC3F (A3F) is a member of the apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like (APOBEC) family of proteins that can deaminate cytosine (C) to uracil (U) on nucleic acids. A3F is one of the four APOBEC members with two Zn-coordinated homologous cytosine deaminase (CD) domains, with the others being A3G, A3D, and A3B. Here we report the in vitro characterization of DNA binding and deaminase activities using purified wild-type and various mutant proteins of A3F from an Escherichia coli expression system. We show that even though CD1 is catalytically inactive and CD2 is the active deaminase domain, presence of CD1 on the N-terminus of CD2 enhances the deaminase activity by over an order of magnitude. This enhancement of CD2 catalytic activity is mainly through the increase of substrate single-stranded (ss) DNA binding by the N-terminal CD1 domain. We further show that the loop 7 of both CD1 and CD2 of A3F plays an important role for ssDNA binding for each individual domain, as well as for the deaminase activity of CD2 domain in the full-length A3F.
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Affiliation(s)
- Qihan Chen
- Molecular and Computational Biology Program, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiao Xiao
- Genetic, Molecular and Cellular Biology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Aaron Wolfe
- Genetic, Molecular and Cellular Biology, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiaojiang S Chen
- Molecular and Computational Biology Program, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA; Center of Excellence in NanoBiophysics, University of Southern California, Los Angeles, CA 90089, USA; Norris Comprehensive Cancer Center; University of Southern California, Los Angeles, CA 90089, USA.
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17
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Bélanger K, Langlois MA. Comparative analysis of the gene-inactivating potential of retroviral restriction factors APOBEC3F and APOBEC3G. J Gen Virol 2015; 96:2878-2887. [PMID: 26048885 DOI: 10.1099/vir.0.000214] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
APOBEC3 (A3) proteins are host-encoded restriction factors that inhibit retrovirus infection by mutagenic deamination of cytosines in minus-strand DNA replication intermediates. APOBEC3F (A3F) and APOBEC3G (A3G) are two of the most potent A3 enzymes in humans with each having a different target DNA specificity. A3G prefers to deaminate cytosines preceded by a cytosine (5'-CC), whereas A3F preferentially targets cytosines preceded by a thymine (5'-TC). Here we performed a detailed comparative analysis of retrovirus-encoded gene sequences edited by A3F and A3G, with the aim of correlating the context and intensity of the mutations with their effects on gene function. Our results revealed that, when there are few (TGG) tryptophan codons in the sequence, both enzymes alter gene function with a similar efficiency when given equal opportunities to deaminate in their preferred target DNA context. In contrast, tryptophan-rich genes are efficiently inactivated in the presence of a low mutational burden, through termination codon generation by A3G but not A3F. Overall, our results clearly demonstrated that the target DNA specificity of an A3 enzyme along with the intensity of the mutational burden and the tryptophan content of the gene being targeted are the factors that have the most forceful influence on whether A3-induced mutations will favour either terminal inactivation or genetic diversification of a retrovirus.
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Affiliation(s)
- Kasandra Bélanger
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Marc-André Langlois
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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18
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Simon V, Bloch N, Landau NR. Intrinsic host restrictions to HIV-1 and mechanisms of viral escape. Nat Immunol 2015; 16:546-53. [PMID: 25988886 PMCID: PMC6908429 DOI: 10.1038/ni.3156] [Citation(s) in RCA: 215] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/24/2015] [Indexed: 02/06/2023]
Abstract
To replicate in their hosts, viruses have to navigate the complexities of the mammalian cell, co-opting mechanisms of cellular physiology while defeating restriction factors that are dedicated to halting their progression. Primate lentiviruses devote a relatively large portion of their coding capacity to counteracting restriction factors by encoding accessory proteins dedicated to neutralizing the antiviral function of these intracellular inhibitors. Research into the roles of the accessory proteins has revealed the existence of previously undetected intrinsic defenses, provided insight into the evolution of primate lentiviruses as they adapt to new species and uncovered new targets for the development of therapeutics. This Review discusses the biology of the restriction factors APOBEC3, SAMHD1 and tetherin and the viral accessory proteins that counteract them.
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Affiliation(s)
- Viviana Simon
- Department of Microbiology, The Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Nicolin Bloch
- Department of Microbiology, NYU School of Medicine, New York, New York, USA
| | - Nathaniel R Landau
- Department of Microbiology, NYU School of Medicine, New York, New York, USA
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19
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Harris RS, Dudley JP. APOBECs and virus restriction. Virology 2015; 479-480:131-45. [PMID: 25818029 PMCID: PMC4424171 DOI: 10.1016/j.virol.2015.03.012] [Citation(s) in RCA: 365] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 02/10/2015] [Accepted: 03/04/2015] [Indexed: 12/22/2022]
Abstract
The APOBEC family of single-stranded DNA cytosine deaminases comprises a formidable arm of the vertebrate innate immune system. Pre-vertebrates express a single APOBEC, whereas some mammals produce as many as 11 enzymes. The APOBEC3 subfamily displays both copy number variation and polymorphisms, consistent with ongoing pathogenic pressures. These enzymes restrict the replication of many DNA-based parasites, such as exogenous viruses and endogenous transposable elements. APOBEC1 and activation-induced cytosine deaminase (AID) have specialized functions in RNA editing and antibody gene diversification, respectively, whereas APOBEC2 and APOBEC4 appear to have different functions. Nevertheless, the APOBEC family protects against both periodic viral zoonoses as well as exogenous and endogenous parasite replication. This review highlights viral pathogens that are restricted by APOBEC enzymes, but manage to escape through unique mechanisms. The sensitivity of viruses that lack counterdefense measures highlights the need to develop APOBEC-enabling small molecules as a new class of anti-viral drugs.
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Affiliation(s)
- Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, Institute for Molecular Virology, Center for Genome Engineering, and Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, United States.
| | - Jaquelin P Dudley
- Department of Molecular Biosciences, Center for Infectious Disease, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, United States.
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20
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Sato K, Takeuchi JS, Misawa N, Izumi T, Kobayashi T, Kimura Y, Iwami S, Takaori-Kondo A, Hu WS, Aihara K, Ito M, An DS, Pathak VK, Koyanagi Y. APOBEC3D and APOBEC3F potently promote HIV-1 diversification and evolution in humanized mouse model. PLoS Pathog 2014; 10:e1004453. [PMID: 25330146 PMCID: PMC4199767 DOI: 10.1371/journal.ppat.1004453] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 09/05/2014] [Indexed: 12/02/2022] Open
Abstract
Several APOBEC3 proteins, particularly APOBEC3D, APOBEC3F, and APOBEC3G, induce G-to-A hypermutations in HIV-1 genome, and abrogate viral replication in experimental systems, but their relative contributions to controlling viral replication and viral genetic variation in vivo have not been elucidated. On the other hand, an HIV-1-encoded protein, Vif, can degrade these APOBEC3 proteins via a ubiquitin/proteasome pathway. Although APOBEC3 proteins have been widely considered as potent restriction factors against HIV-1, it remains unclear which endogenous APOBEC3 protein(s) affect HIV-1 propagation in vivo. Here we use a humanized mouse model and HIV-1 with mutations in Vif motifs that are responsible for specific APOBEC3 interactions, DRMR/AAAA (4A) or YRHHY/AAAAA (5A), and demonstrate that endogenous APOBEC3D/F and APOBEC3G exert strong anti-HIV-1 activity in vivo. We also show that the growth kinetics of 4A HIV-1 negatively correlated with the expression level of APOBEC3F. Moreover, single genome sequencing analyses of viral RNA in plasma of infected mice reveal that 4A HIV-1 is specifically and significantly diversified. Furthermore, a mutated virus that is capable of using both CCR5 and CXCR4 as entry coreceptor is specifically detected in 4A HIV-1-infected mice. Taken together, our results demonstrate that APOBEC3D/F and APOBEC3G fundamentally work as restriction factors against HIV-1 in vivo, but at the same time, that APOBEC3D and APOBEC3F are capable of promoting viral diversification and evolution in vivo. Mutation can produce three outcomes in viruses: detrimental, neutral, or beneficial. The first one leads to abrogation of virus replication because of error catastrophe, while the last one lets the virus escape from anti-viral immune system or adapt to the host. Human APOBEC3D, APOBEC3F, and APOBEC3G are cellular cytidine deaminases which cause G-to-A mutations in HIV-1 genome. Here we use a humanized mouse model and demonstrate that endogenous APOBEC3F and APOBEC3G induce G-to-A hypermutation in viral genomes and exert strong anti-HIV-1 activity in vivo. We also reveal that endogenous APOBEC3D and/or APOBEC3F induce viral diversification, which can lead to the emergence of a mutated virus that converts its coreceptor usage. Our results suggest that APOBEC3D and APOBEC3F are capable of promoting viral diversification and functional evolution in vivo.
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Affiliation(s)
- Kei Sato
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto, Japan
- * E-mail:
| | - Junko S. Takeuchi
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto, Japan
| | - Naoko Misawa
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto, Japan
| | - Taisuke Izumi
- Viral Mutation Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, Maryland, United States of America
| | - Tomoko Kobayashi
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto, Japan
| | - Yuichi Kimura
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto, Japan
| | - Shingo Iwami
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Fukuoka, Japan
| | - Akifumi Takaori-Kondo
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan
| | - Wei-Shau Hu
- Viral Recombination Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, Maryland, United States of America
| | - Kazuyuki Aihara
- Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, Japan
- Graduate School of Information Science and Technology, The University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Mamoru Ito
- Central Institute for Experimental Animals, Kawasaki, Kanagawa, Japan
| | - Dong Sung An
- Division of Hematology and Oncology, University of California, Los Angeles, Los Angeles, California, United States of America
- School of Nursing, University of California, Los Angeles, Los Angeles, California, United States of America
- AIDS Institute, University of California, Los Angeles, Los Angeles, California, United States of America
| | - Vinay K. Pathak
- Viral Mutation Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, Maryland, United States of America
| | - Yoshio Koyanagi
- Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, Kyoto, Kyoto, Japan
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21
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Feng Y, Baig TT, Love RP, Chelico L. Suppression of APOBEC3-mediated restriction of HIV-1 by Vif. Front Microbiol 2014; 5:450. [PMID: 25206352 PMCID: PMC4144255 DOI: 10.3389/fmicb.2014.00450] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 08/06/2014] [Indexed: 12/21/2022] Open
Abstract
The APOBEC3 restriction factors are a family of deoxycytidine deaminases that are able to suppress replication of viruses with a single-stranded DNA intermediate by inducing mutagenesis and functional inactivation of the virus. Of the seven human APOBEC3 enzymes, only APOBEC3-D, -F, -G, and -H appear relevant to restriction of HIV-1 in CD4+ T cells and will be the focus of this review. The restriction of HIV-1 occurs most potently in the absence of HIV-1 Vif that induces polyubiquitination and degradation of APOBEC3 enzymes through the proteasome pathway. To restrict HIV-1, APOBEC3 enzymes must be encapsidated into budding virions. Upon infection of the target cell during reverse transcription of the HIV-1 RNA into (-)DNA, APOBEC3 enzymes deaminate cytosines to form uracils in single-stranded (-)DNA regions. Upon replication of the (-)DNA to (+)DNA, the HIV-1 reverse transcriptase incorporates adenines opposite to the uracils thereby inducing C/G to T/A mutations that can functionally inactivate HIV-1. APOBEC3G is the most studied APOBEC3 enzyme and it is known that Vif attempts to thwart APOBEC3 function not only by inducing its proteasomal degradation but also by several degradation-independent mechanisms, such as inhibiting APOBEC3G virion encapsidation, mRNA translation, and for those APOBEC3G molecules that still become virion encapsidated, Vif can inhibit APOBEC3G mutagenic activity. Although most Vif variants can induce efficient degradation of APOBEC3-D, -F, and -G, there appears to be differential sensitivity to Vif-mediated degradation for APOBEC3H. This review examines APOBEC3-mediated HIV restriction mechanisms, how Vif acts as a substrate receptor for a Cullin5 ubiquitin ligase complex to induce degradation of APOBEC3s, and the determinants and functional consequences of the APOBEC3 and Vif interaction from a biological and biochemical perspective.
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Affiliation(s)
- Yuqing Feng
- Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan Saskatoon, SK, Canada
| | - Tayyba T Baig
- Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan Saskatoon, SK, Canada
| | - Robin P Love
- Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan Saskatoon, SK, Canada
| | - Linda Chelico
- Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan Saskatoon, SK, Canada
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