1
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Jiang Y, Wang Y, Wang Z, Zhang Y, Hou Y, Wang X. Anoikis-related genes signature development for clear cell renal cell carcinoma prognosis and tumor microenvironment. Sci Rep 2023; 13:18909. [PMID: 37919386 PMCID: PMC10622575 DOI: 10.1038/s41598-023-46398-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 10/31/2023] [Indexed: 11/04/2023] Open
Abstract
Clear cell renal cell carcinoma (ccRCC) is one of the most common primary malignancies of the urinary tract, highly heterogeneous, and increasing in incidence worldwide. Anoikis is a specific type of programmed cell death in which solid tumor cells or normal epithelial cells that do not have metastatic properties lose adhesion to the extracellular matrix or undergo inappropriate cell adhesion-induced apoptosis. Anoikis is thought to play a critical role in tumorigenesis, maintenance, and treatment, according to an increasing amount of research. However, there is still some uncertainty regarding the general impact of anoikis-related genes (ARGs) on the prognostic importance, tumor microenvironment characteristics, and treatment reaction of ccRCC patients. For this study, we used The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus datasets to access the RNA sequencing results and clinical information from ccRCC patients. 29 ARGs related to survival were found using differential analysis and univariate Cox regression analysis. The samples were then divided into two clusters that had different immune traits via unsupervised cluster analysis using 29 prognosis-associated differently expressed ARGs. Then, to build an ARGs signature, 7 genes (PLAU, EDA2R, AFP, PLG, TUBB3, APOBEC3G, and MALAT1) were found using Least Absolute Shrinkage and Selection Operator regression analysis. The new ARGs signature demonstrated outstanding prognostic capability for ccRCC patients' overall survival. In conclusion, for ccRCC patients, we created an ARGs signature that strongly connects to immunological traits and therapy response. Clinicians may find this ARGs signature helpful in developing more individualized and detailed treatment strategies for ccRCC patients.
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Affiliation(s)
- Yinglei Jiang
- Dialysis Room, The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, 120000, China
| | - Ying Wang
- Dialysis Room, The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, 120000, China
| | - Zhengyan Wang
- Changchun University of Chinese Medicine, Changchun, 120000, China
| | - Yinzhen Zhang
- Changchun University of Chinese Medicine, Changchun, 120000, China
| | - Yulong Hou
- Changchun University of Chinese Medicine, Changchun, 120000, China
| | - Xukai Wang
- Dialysis Room, The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, 120000, China.
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2
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Kouno T, Shibata S, Shigematsu M, Hyun J, Kim TG, Matsuo H, Wolf M. Structural insights into RNA bridging between HIV-1 Vif and antiviral factor APOBEC3G. Nat Commun 2023; 14:4037. [PMID: 37419875 PMCID: PMC10328928 DOI: 10.1038/s41467-023-39796-5] [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: 02/14/2023] [Accepted: 06/29/2023] [Indexed: 07/09/2023] Open
Abstract
Great effort has been devoted to discovering the basis of A3G-Vif interaction, the key event of HIV's counteraction mechanism to evade antiviral innate immune response. Here we show reconstitution of the A3G-Vif complex and subsequent A3G ubiquitination in vitro and report the cryo-EM structure of the A3G-Vif complex at 2.8 Å resolution using solubility-enhanced variants of A3G and Vif. We present an atomic model of the A3G-Vif interface, which assembles via known amino acid determinants. This assembly is not achieved by protein-protein interaction alone, but also involves RNA. The cryo-EM structure and in vitro ubiquitination assays identify an adenine/guanine base preference for the interaction and a unique Vif-ribose contact. This establishes the biological significance of an RNA ligand. Further assessment of interactions between A3G, Vif, and RNA ligands show that the A3G-Vif assembly and subsequent ubiquitination can be controlled by amino acid mutations at the interface or by polynucleotide modification, suggesting that a specific chemical moiety would be a promising pharmacophore to inhibit the A3G-Vif interaction.
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Affiliation(s)
- Takahide Kouno
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan.
| | - Satoshi Shibata
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
- Division of Bacteriology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago-shi, Tottori, 683-8503, Japan
| | - Megumi Shigematsu
- Computational Medicine Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Jaekyung Hyun
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
- School of Pharmacy, Sungkyunkwan University, Suwon-si, Gyeonggi-do, 16419, Republic of Korea
| | - Tae Gyun Kim
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
- Department of Efficacy Evaluation, Innovation Center for Vaccine Industry, Gyeongbuk Institute for Bio Industry, Gyeongsanbuk-do, 36618, Republic of Korea
| | - Hiroshi Matsuo
- Cancer Innovation Laboratory, Frederick National Laboratory for Cancer Research, Frederick, MD, 21702, USA
| | - Matthias Wolf
- Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan.
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road Sec. 2, 115, Taipei, Taiwan.
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3
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Maeda R, Fujita J, Konishi Y, Kazuma Y, Yamazaki H, Anzai I, Watanabe T, Yamaguchi K, Kasai K, Nagata K, Yamaoka Y, Miyakawa K, Ryo A, Shirakawa K, Sato K, Makino F, Matsuura Y, Inoue T, Imura A, Namba K, Takaori-Kondo A. A panel of nanobodies recognizing conserved hidden clefts of all SARS-CoV-2 spike variants including Omicron. Commun Biol 2022; 5:669. [PMID: 35794202 PMCID: PMC9257560 DOI: 10.1038/s42003-022-03630-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 06/24/2022] [Indexed: 12/15/2022] Open
Abstract
We are amid the historic coronavirus infectious disease 2019 (COVID-19) pandemic. Imbalances in the accessibility of vaccines, medicines, and diagnostics among countries, regions, and populations, and those in war crises, have been problematic. Nanobodies are small, stable, customizable, and inexpensive to produce. Herein, we present a panel of nanobodies that can detect the spike proteins of five SARS-CoV-2 variants of concern (VOCs) including Omicron. Here we show via ELISA, lateral flow, kinetic, flow cytometric, microscopy, and Western blotting assays that our nanobodies can quantify the spike variants. This panel of nanobodies broadly neutralizes viral infection caused by pseudotyped and authentic SARS-CoV-2 VOCs. Structural analyses show that the P86 clone targets epitopes that are conserved yet unclassified on the receptor-binding domain (RBD) and contacts the N-terminal domain (NTD). Human antibodies rarely access both regions; consequently, the clone buries hidden crevasses of SARS-CoV-2 spike proteins that go undetected by conventional antibodies. A panel of nanobodies are presented that can detect the spike proteins of five SARS-CoV-2 variants of concern and structural analyses show that one clone targets conserved epitopes on the receptor-binding domain and contacts the N-terminal domain.
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4
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Schlafens Can Put Viruses to Sleep. Viruses 2022; 14:v14020442. [PMID: 35216035 PMCID: PMC8875196 DOI: 10.3390/v14020442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 12/21/2022] Open
Abstract
The Schlafen gene family encodes for proteins involved in various biological tasks, including cell proliferation, differentiation, and T cell development. Schlafens were initially discovered in mice, and have been studied in the context of cancer biology, as well as their role in protecting cells during viral infection. This protein family provides antiviral barriers via direct and indirect effects on virus infection. Schlafens can inhibit the replication of viruses with both RNA and DNA genomes. In this review, we summarize the cellular functions and the emerging relationship between Schlafens and innate immunity. We also discuss the functions and distinctions of this emerging family of proteins as host restriction factors against viral infection. Further research into Schlafen protein function will provide insight into their mechanisms that contribute to intrinsic and innate host immunity.
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5
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Regulation of Viral Restriction by Post-Translational Modifications. Viruses 2021; 13:v13112197. [PMID: 34835003 PMCID: PMC8618861 DOI: 10.3390/v13112197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 12/17/2022] Open
Abstract
Intrinsic immunity is orchestrated by a wide range of host cellular proteins called restriction factors. They have the capacity to interfere with viral replication, and most of them are tightly regulated by interferons (IFNs). In addition, their regulation through post-translational modifications (PTMs) constitutes a major mechanism to shape their action positively or negatively. Following viral infection, restriction factor modification can be decisive. Palmitoylation of IFITM3, SUMOylation of MxA, SAMHD1 and TRIM5α or glycosylation of BST2 are some of those PTMs required for their antiviral activity. Nonetheless, for their benefit and by manipulating the PTMs machinery, viruses have evolved sophisticated mechanisms to counteract restriction factors. Indeed, many viral proteins evade restriction activity by inducing their ubiquitination and subsequent degradation. Studies on PTMs and their substrates are essential for the understanding of the antiviral defense mechanisms and provide a global vision of all possible regulations of the immune response at a given time and under specific infection conditions. Our aim was to provide an overview of current knowledge regarding the role of PTMs on restriction factors with an emphasis on their impact on viral replication.
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6
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APOBECs orchestrate genomic and epigenomic editing across health and disease. Trends Genet 2021; 37:1028-1043. [PMID: 34353635 DOI: 10.1016/j.tig.2021.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 07/03/2021] [Accepted: 07/05/2021] [Indexed: 12/17/2022]
Abstract
APOBEC proteins can deaminate cytosine residues in DNA and RNA. This can lead to somatic mutations, DNA breaks, RNA modifications, or DNA demethylation in a selective manner. APOBECs function in various cellular compartments and recognize different nucleic acid motifs and structures. They orchestrate a wide array of genomic and epigenomic modifications, thereby affecting various cellular functions positively or negatively, including immune editing, viral and retroelement restriction, DNA damage responses, DNA demethylation, gene expression, and tissue homeostasis. Furthermore, the cumulative increase in genomic and epigenomic editing with aging could also, at least in part, be attributed to APOBEC function. We synthesize our cumulative understanding of APOBEC activity in a unifying overview and discuss their genomic and epigenomic impact in physiological, pathological, and technological contexts.
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7
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Ikeda T, Yue Y, Shimizu R, Nasser H. Potential Utilization of APOBEC3-Mediated Mutagenesis for an HIV-1 Functional Cure. Front Microbiol 2021; 12:686357. [PMID: 34211449 PMCID: PMC8239295 DOI: 10.3389/fmicb.2021.686357] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
The introduction of combination antiretroviral therapy (cART) has managed to control the replication of human immunodeficiency virus type 1 (HIV-1) in infected patients. However, a complete HIV-1 cure, including a functional cure for or eradication of HIV-1, has yet to be achieved because of the persistence of latent HIV-1 reservoirs in adherent patients. The primary source of these viral reservoirs is integrated proviral DNA in CD4+ T cells and other non-T cells. Although a small fraction of this proviral DNA is replication-competent and contributes to viral rebound after the cessation of cART, >90% of latent viral reservoirs are replication-defective and some contain high rates of G-to-A mutations in proviral DNA. At least in part, these high rates of G-to-A mutations arise from the APOBEC3 (A3) family proteins of cytosine deaminases. A general model has shown that the HIV-1 virus infectivity factor (Vif) degrades A3 family proteins by proteasome-mediated pathways and inactivates their antiviral activities. However, Vif does not fully counteract the HIV-1 restriction activity of A3 family proteins in vivo, as indicated by observations of A3-mediated G-to-A hypermutation in the proviral DNA of HIV-1-infected patients. The frequency of A3-mediated hypermutation potentially contributes to slower HIV-1/AIDS disease progression and virus evolution including the emergence of cytotoxic T lymphocyte escape mutants. Therefore, combined with other strategies, the manipulation of A3-mediated mutagenesis may contribute to an HIV-1 functional cure aimed at cART-free remission. In this mini-review, we discuss the possibility of an HIV-1 functional cure arising from manipulation of A3 mutagenic activity.
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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
| | - Yuan Yue
- 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
| | - 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
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8
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Phosphorylation-Dependent SERS Readout for Activity Assay of Protein Kinase A in Cell Extracts. NANOMATERIALS 2020; 10:nano10030575. [PMID: 32235706 PMCID: PMC7153394 DOI: 10.3390/nano10030575] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 12/13/2022]
Abstract
Protein kinases are key regulators of cell function, the abnormal activity of which may induce several human diseases, including cancers. Therefore, it is of great significance to develop a sensitive and reliable method for assaying protein kinase activities in real biological samples. Here, we report the phosphorylation-dependent surface-enhanced Raman scattering (SERS) readout of spermine-functionalized silver nanoparticles (AgNPs) for protein kinase A (PKA) activity assay in cell extracts. In this assay, the presence of PKA would phosphorylate and alter the net charge states of Raman dye-labeled substrate peptides, and the resulting anionic products could absorb onto the AgNPs with cationic surface charge through electrostatic attraction. Meanwhile, the Raman signals of dyes labeled on peptides were strongly enhanced by the aggregated AgNPs with interparticle hot spots formed in assay buffer. The SERS readout was directly proportional to the PKA activity in a wide range of 0.0001-0.5 U·μL-1 with a detection limit as low as 0.00003 U·μL-1. Moreover, the proposed SERS-based assay for the PKA activity was successfully applied to monitoring the activity and inhibition of PKA in real biological samples, particularly in cell extracts, which would be beneficial for kinase-related disease diagnostics and inhibitor screening.
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9
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IL-27 posttranslationally regulates Y-box binding protein-1 to inhibit HIV-1 replication in human CD4+ T cells. AIDS 2019; 33:1819-1830. [PMID: 31274540 PMCID: PMC6731144 DOI: 10.1097/qad.0000000000002288] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
IL-27 is known as an antiviral cytokine that inhibits HIV, hepatitis C virus, and other viruses. We have previously demonstrated that, IL-27 posttreatment after HIV-infection inhibits viral replication in primary CD4+ T cells.
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10
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Luan Z, Zhao L, Liu C, Song W, He P, Zhang X. Detection of casein kinase II by aggregation-induced emission. Talanta 2019; 201:450-454. [PMID: 31122448 DOI: 10.1016/j.talanta.2019.04.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/12/2019] [Accepted: 04/14/2019] [Indexed: 10/27/2022]
Abstract
A novel aggregation-induced emission (AIE) probe comprised of a hydrophilic protein kinase specific peptide and a hydrophobic tetraphenylethene (TPE) unit was synthesized through click reaction. The prepared TPE-peptide probe could be completely degraded by carboxypeptidase Y (CPY) to release hydrophobic TPE part, which aggregated in buffer solution and showed strong TPE emission. In the presence of casein kinase (CKII), the phosphorylation of peptide prevented the complete degradation by CPY producing the nonemissive probe. Thus, the developed probe can be used to detect CKII homogeneously and conveniently. This detection process can be finished within 1.5 h with high sensitivity (0.05 mU/μL) and good selectivity. The developed method can also be used to screen protein kinase inhibitor even in a complex biological system.
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Affiliation(s)
- Zhenzhu Luan
- Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, Key Laboratory of Biochemical Analysis, Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, PR China
| | - Li Zhao
- Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, Key Laboratory of Biochemical Analysis, Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, PR China
| | - Chao Liu
- Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, Key Laboratory of Biochemical Analysis, Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, PR China
| | - Weiling Song
- Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, Key Laboratory of Biochemical Analysis, Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, PR China
| | - Peng He
- Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, Key Laboratory of Biochemical Analysis, Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, PR China
| | - Xiaoru Zhang
- Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, Key Laboratory of Biochemical Analysis, Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, MOE, Shandong Key Laboratory of Biochemical Analysis, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, PR China.
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11
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Protein kinase A inhibits tumor mutator APOBEC3B through phosphorylation. Sci Rep 2019; 9:8307. [PMID: 31165764 PMCID: PMC6549188 DOI: 10.1038/s41598-019-44407-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 05/14/2019] [Indexed: 12/26/2022] Open
Abstract
APOBEC3B cytidine deaminase (A3B) catalyzes cytosine into uracil in single-strand DNA and induces C-to-T mutations in genomic DNA of various types of tumors. Accumulation of APOBEC signature mutations is correlated with a worse prognosis for patients with breast cancer or multiple myeloma, suggesting that A3B activity might be a cause of the unfavorable DNA mutations and clonal evolution in these tumors. Phosphorylation of conserved threonine residues of other cytidine deaminases, activation induced deaminase (AID) and APOBEC3G, inhibits their activity. Here we show that protein kinase A (PKA) physically binds to A3B and phosphorylates Thr214. In vitro deaminase assays and foreign DNA editing assays in cells confirm that phosphomimetic A3B mutants, T214D and T214E, completely lose deaminase activity. Molecular dynamics simulation of A3B phosphorylation reveals that Thr214 phosphorylation disrupts binding between the phospho-A3B catalytic core and ssDNA. These mutants still inhibit retroviral infectivity at least partially, and also retain full anti-retrotransposition activity. These results imply that PKA-mediated phosphorylation inhibits A3B mutagenic activity without destructing its innate immune functions. Therefore, PKA activation could reduce further accumulation of mutations in A3B overexpressing tumors.
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12
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Yoshinaga N, Shindo K, Matsui Y, Takiuchi Y, Fukuda H, Nagata K, Shirakawa K, Kobayashi M, Takeda S, Takaori-Kondo A. A screening for DNA damage response molecules that affect HIV-1 infection. Biochem Biophys Res Commun 2019; 513:93-98. [PMID: 30935695 DOI: 10.1016/j.bbrc.2019.03.168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 03/26/2019] [Indexed: 01/14/2023]
Abstract
Host DNA damage response molecules affect retroviral infection, as DNA intermediates of the viruses play essential roles in the viral life cycles. Although several such molecules have been reported, interactions between HIV-1 and host DNA damage response molecules have not been fully elucidated. To screen DNA damage response molecules that might affect HIV-1 infection, a set of 32 DNA-repair-deficient DT40 isogenic mutant cells were tested for HIV-1 infectivity. Seven out of the 32 clones showed less than 50% infectivity compared to parental DT40 cells, implying that DNA repair molecules deficient in these cells might support HIV-1 infection. Of these, EXO1 -/-, TP53BP1 -/- and WRN -/- cells showed more than twofold accumulation of two long terminal repeat circles and less than 50% integrated proviral DNA in quantitative-PCR analyses, indicating that the integration step is impaired. RAD18 -/- cells showed twofold higher HIV-1 infectivity and increased reverse transcription products at earlier time points, suggesting that RAD18 suppresses reverse transcription. The HIV-1 suppressive effects of RAD18 were confirmed by over-expression and knockdown experiments in human cells. L274P, a DNA-binding-impaired mutant of RAD18, showed impaired HIV-1 suppression and DNA binding, suggesting that binding HIV-1 DNA intermediates is critical for RAD18 to suppress reverse transcription and HIV-1 infection. Our data help understand interactions between host DNA damage response molecules and viral DNA.
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Affiliation(s)
- Noriyoshi Yoshinaga
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan
| | - Keisuke Shindo
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan.
| | - Yusuke Matsui
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan
| | - Yoko Takiuchi
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan
| | - Hirofumi Fukuda
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan
| | - Kayoko Nagata
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan
| | - Kotaro Shirakawa
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan
| | - Masayuki Kobayashi
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Japan
| | - Akifumi Takaori-Kondo
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Japan
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13
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Copper nanoclusters/polydopamine nanospheres based fluorescence aptasensor for protein kinase activity determination. Anal Chim Acta 2018; 1035:184-191. [PMID: 30224138 DOI: 10.1016/j.aca.2018.06.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/13/2018] [Accepted: 06/15/2018] [Indexed: 11/22/2022]
Abstract
A fluorescence aptasensor was constructed for protein kinase (PKA) activity detection by utilizing copper nanoclusters (CuNCs) and polydopamine nanospheres (PDANS). Through the π-π stacking interactions between adenosine triphosphate (ATP) aptamer and PDANS, the ATP aptamer modified CuNCs (apt-CuNCs) were absorbed onto PDANS surface, thus the fluorescence of apt-CuNCs were quenched through fluorescence resonance energy transfer (FRET) from apt-CuNCs to PDANS. In the presence of ATP, ATP specifically bound to aptamer, causing the dissociation of apt-CuNCs from PDANS surface and restoring the fluorescence of apt-CuNCs. However, PKA translated ATP into adenosine diphosphate (ADP), and ADP had no competence to combine with ATP aptamer, thus, apt-CuNCs were released and absorbed onto the PDANS surface to cause the fluorescence quenching of apt-CuNCs again. Therefore, PKA activity was conveniently detected via the fluorescence signal change. Under the optimal conditions, PKA activity was detected in the range of 0.05-4.5 U mL-1 with a detection limit of 0.021 U mL-1. Furthermore, the feasibility of the aptasensor for kinase inhibitor screening was explored via assessment of kinase inhibitor H-89 as one model. This aptasensor was also performed for PKA activity determination in HepG2 cell lysates with satisfactory results.
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14
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Temerozo JR, de Azevedo SSD, Insuela DBR, Vieira RC, Ferreira PLC, Carvalho VF, Bello G, Bou-Habib DC. The Neuropeptides Vasoactive Intestinal Peptide and Pituitary Adenylate Cyclase-Activating Polypeptide Control HIV-1 Infection in Macrophages Through Activation of Protein Kinases A and C. Front Immunol 2018; 9:1336. [PMID: 29951068 PMCID: PMC6008521 DOI: 10.3389/fimmu.2018.01336] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 05/29/2018] [Indexed: 12/19/2022] Open
Abstract
Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are highly similar neuropeptides present in several tissues, endowed with immunoregulatory functions and other systemic effects. We previously reported that both neuropeptides reduce viral production in HIV-1-infected primary macrophages, with the participation of β-chemokines and IL-10, and now we describe molecular mechanisms engaged in this activity. Macrophages exposed to VIP or PACAP before HIV-1 infection showed resistance to viral replication, comparable to that observed when the cells were treated after infection. Also, multiple treatments with a suboptimal dose of VIP or PACAP after macrophage infection resulted in a decline of virus production similar to the inhibition promoted by a single exposure to the optimal inhibitory concentration. Cellular signaling pathways involving cAMP production and activation of protein kinases A and C were critical components of the VIP and PACAP anti-HIV-1 effects. Analysis of the transcription factors and the transcriptional/cell cycle regulators showed that VIP and PACAP induced cAMP response element-binding protein activation, inhibited NF-kB, and reduced Cyclin D1 levels in HIV-1-infected cells. Remarkably, VIP and PACAP promoted G-to-A mutations in the HIV-1 provirus, matching those derived from the activity of the APOBEC family of viral restriction factors, and reduced viral infectivity. In conclusion, our findings strengthen the antiretroviral potential of VIP and PACAP and point to new therapeutic approaches to control the progression of HIV-1 infection.
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Affiliation(s)
- Jairo R Temerozo
- Laboratory on Thymus Research, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Suwellen S D de Azevedo
- Laboratory of AIDS and Molecular Immunology, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Daniella B R Insuela
- Laboratory of Inflammation, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Rhaíssa C Vieira
- Laboratory on Thymus Research, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Pedro L C Ferreira
- Laboratory on Thymus Research, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Vinícius F Carvalho
- National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil.,Laboratory of Inflammation, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Gonzalo Bello
- Laboratory of AIDS and Molecular Immunology, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Dumith Chequer Bou-Habib
- Laboratory on Thymus Research, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil.,National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
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15
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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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16
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Zhai C, Ma L, Zhang Z, Ding J, Wang J, Zhang Y, Li X, Guo F, Yu L, Zhou J, Cen S. Identification and characterization of loop7 motif and its role in regulating biological function of human APOBEC3G through molecular modeling and biological assay. Acta Pharm Sin B 2017; 7:571-582. [PMID: 28924551 PMCID: PMC5595295 DOI: 10.1016/j.apsb.2017.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/19/2017] [Accepted: 04/21/2017] [Indexed: 02/06/2023] Open
Abstract
Human APOBEC3G (hA3G) is a cytidine deaminase which inhibits HIV-1 replication. The HIV-1 accessory protein viral infectivity factor (Vif) counteracts with hA3G by targeting it for proteasomal degradation. In this work, we constructed and optimized molecular models of the hA3G dimer and the hA3G–Vif complex. The molecular modeling study revealed that the loop7 motif of hA3G appears on the interfaces of both the hA3G–Vif complex and the hA3G dimer. Biochemical analysis provided evidence suggesting that binding of Vif to hA3G results in steric blocking of hA3G dimerization, implying that monomeric hA3G serves as a substrate for Vif-mediated degradation. Furthermore, we presented evidence for the important roles of the loop7 motif, especially the central residues within the region, in hA3G dimerization, hA3G--Vif interaction, Vif-mediated hA3G degradation as well as subcellular localization of hA3G. This work highlights a multiple-task interface formed by loop7 motif, which regulates biological function of hA3G, thus providing the feasibility of the strategy of blocking Vif-mediated A3G degradation by targeting the putative site around loop7.
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17
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Xie W, Agniel D, Shevchenko A, Malov SV, Svitin A, Cherkasov N, Baum MK, Campa A, Gaseitsiwe S, Bussmann H, Makhema J, Marlink R, Novitsky V, Lee TH, Cai T, O'Brien SJ, Essex M. Genome-Wide Analyses Reveal Gene Influence on HIV Disease Progression and HIV-1C Acquisition in Southern Africa. AIDS Res Hum Retroviruses 2017; 33:597-609. [PMID: 28132517 DOI: 10.1089/aid.2016.0017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Sub-Saharan Africans infected with HIV-1C make up the largest AIDS patient population in the world and exhibit large heterogeneity in disease progression before initiating antiretroviral therapy. To identify host variants associated with HIV disease progression, we performed genome-wide association studies on a total of 556 treatment-naive HIV-infected individuals in Botswana. We characterized the pattern of HIV disease progression using a novel functional principal component analysis, which can better capture longitudinal CD4 and viral load (VL) trajectories. Two single-nucleotide polymorphisms (SNPs) near HCG22 (chr6, peak variant rs2535307, combined p = 3.72 × 10-7, minor allele as risky allele) and CCNG1 (chr5, peak variant kgp22385164, combined p = 1.88 × 10-6, minor allele as risky allele) were significantly associated with CD4 and VL dynamics. Inspection of SNPs in these gene regions in a third Botswana cohort (using GWATCH) also revealed a strong association of HCG22 with HIV-1C acquisition, suggesting that this region is associated with infection as well as disease progression. Our study uncovered two genetic regions that are significant and have specific effects on HIV-1C acquisition or progression in sub-Saharan Africans, and the result suggested new potential targets for AIDS prevention and treatment. In addition, our results also indicate the possibility of using genetic markers as HIV disease progression indicators in sub-Saharan Africans to prioritize fast progressors for antiretroviral treatment.
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Affiliation(s)
- Wen Xie
- Harvard T.H. Chan School of Public Health AIDS Initiative, Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - Denis Agniel
- Department of Biomedical Informatics, Harvard Medical School, Boston, Massachusetts
| | - Andrey Shevchenko
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg, Russia
| | - Sergey V. Malov
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg, Russia
- Department of Mathematics, St. Petersburg Electrotechnical University, St Petersburg, Russia
| | - Anton Svitin
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg, Russia
| | - Nikolay Cherkasov
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg, Russia
| | - Marianna K. Baum
- Department of Dietetics and Nutrition, Robert Stempel College of Public Health & Social Work, Florida International University, Miami, Florida
| | - Adriana Campa
- Department of Dietetics and Nutrition, Robert Stempel College of Public Health & Social Work, Florida International University, Miami, Florida
| | - Simani Gaseitsiwe
- Harvard T.H. Chan School of Public Health AIDS Initiative, Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - Hermann Bussmann
- Harvard T.H. Chan School of Public Health AIDS Initiative, Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - Joseph Makhema
- Harvard T.H. Chan School of Public Health AIDS Initiative, Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - Richard Marlink
- Harvard T.H. Chan School of Public Health AIDS Initiative, Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - Vladimir Novitsky
- Harvard T.H. Chan School of Public Health AIDS Initiative, Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
| | - Tun-Hou Lee
- Harvard T.H. Chan School of Public Health AIDS Initiative, Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Tianxi Cai
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Stephen J. O'Brien
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg, Russia
- Oceanographic Center, Nova Southeastern University, Ft. Lauderdale, Florida
| | - M. Essex
- Harvard T.H. Chan School of Public Health AIDS Initiative, Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Botswana Harvard AIDS Institute, Gaborone, Botswana
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18
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Shi K, Carpenter M, Banerjee S, Shaban N, Kurahashi K, Salamango D, McCann J, Starrett G, Duffy J, Demir Ö, Amaro R, Harki D, Harris R, Aihara H. Structural basis for targeted DNA cytosine deamination and mutagenesis by APOBEC3A and APOBEC3B. Nat Struct Mol Biol 2017; 24:131-139. [PMID: 27991903 PMCID: PMC5296220 DOI: 10.1038/nsmb.3344] [Citation(s) in RCA: 176] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 11/16/2016] [Indexed: 12/17/2022]
Abstract
APOBEC-catalyzed cytosine-to-uracil deamination of single-stranded DNA (ssDNA) has beneficial functions in immunity and detrimental effects in cancer. APOBEC enzymes have intrinsic dinucleotide specificities that impart hallmark mutation signatures. Although numerous structures have been solved, mechanisms for global ssDNA recognition and local target-sequence selection remain unclear. Here we report crystal structures of human APOBEC3A and a chimera of human APOBEC3B and APOBEC3A bound to ssDNA at 3.1-Å and 1.7-Å resolution, respectively. These structures reveal a U-shaped DNA conformation, with the specificity-conferring -1 thymine flipped out and the target cytosine inserted deep into the zinc-coordinating active site pocket. The -1 thymine base fits into a groove between flexible loops and makes direct hydrogen bonds with the protein, accounting for the strong 5'-TC preference. These findings explain both conserved and unique properties among APOBEC family members, and they provide a basis for the rational design of inhibitors to impede the evolvability of viruses and tumors.
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Affiliation(s)
- K. Shi
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - M.A. Carpenter
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - S. Banerjee
- Northeastern Collaborative Access Team, Cornell University, Advanced Photon Source, Lemont, Illinois, USA, 60439
| | - N.M. Shaban
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - K. Kurahashi
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - D.J. Salamango
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - J.L. McCann
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - G.J. Starrett
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - J.V. Duffy
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - Ö. Demir
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093
| | - R.E. Amaro
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093
| | - D.A. Harki
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - R.S. Harris
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, Minnesota, USA, 55455
| | - H. Aihara
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota, USA, 55455
- Institute for Molecular Virology, University of Minnesota, Minneapolis, Minnesota, USA, 55455
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19
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Abstract
The AID/APOBEC family enzymes convert cytosines in single-stranded DNA to uracils, causing base substitutions and strand breaks. They are induced by cytokines produced during the body's inflammatory response to infections, and they help combat infections through diverse mechanisms. AID is essential for the maturation of antibodies and causes mutations and deletions in antibody genes through somatic hypermutation (SHM) and class-switch recombination (CSR) processes. One member of the APOBEC family, APOBEC1, edits mRNA for a protein involved in lipid transport. Members of the APOBEC3 subfamily in humans (APOBEC3A, APOBEC3B, APOBEC3C, APOBEC3D, APOBEC3F, APOBEC3G, and APOBEC3H) inhibit infections of viruses such as HIV-1, HBV, and HCV, and retrotransposition of endogenous retroelements through mutagenic and nonmutagenic mechanisms. There is emerging consensus that these enzymes can cause mutations in the cellular genome at replication forks or within transcription bubbles depending on the physiological state of the cell and the phase of the cell cycle during which they are expressed. We describe here the state of knowledge about the structures of these enzymes, regulation of their expression, and both the advantageous and deleterious consequences of their expression, including carcinogenesis. We highlight similarities among them and present a holistic view of their regulation and function.
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Affiliation(s)
- Sachini U Siriwardena
- Department of Chemistry, Wayne State University , Detroit, Michigan 48202, United States
| | - Kang Chen
- Department of Obstetrics and Gynecology, Wayne State University , Detroit, Michigan 48201, United States
- Mucosal Immunology Studies Team, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
- Department of Immunology and Microbiology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
| | - Ashok S Bhagwat
- Department of Chemistry, Wayne State University , Detroit, Michigan 48202, United States
- Department of Immunology and Microbiology, Wayne State University School of Medicine , Detroit, Michigan 48201, United States
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20
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Lim HW, Kang SG, Ryu JK, Schilling B, Fei M, Lee IS, Kehasse A, Shirakawa K, Yokoyama M, Schnölzer M, Kasler HG, Kwon HS, Gibson BW, Sato H, Akassoglou K, Xiao C, Littman DR, Ott M, Verdin E. SIRT1 deacetylates RORγt and enhances Th17 cell generation. ACTA ACUST UNITED AC 2015; 212:607-17. [PMID: 25918343 PMCID: PMC4419343 DOI: 10.1084/jem.20132378] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 04/03/2015] [Indexed: 01/30/2023]
Abstract
Lim et al. demonstrate that protein deacetylase, Sirtuin 1, promotes autoimmunity by deacetylating RORγt increasing its transcriptional activity and promoting Th17 differentiation and function. Blockade or loss of Sirtuin 1 results in protection from multiple sclerosis-like disease in mice. The balance of effector and regulatory T cell function, dependent on multiple signals and epigenetic regulators, is critical to immune self-tolerance. Dysregulation of T helper 17 (Th17) effector cells is associated with multiple autoimmune diseases, including multiple sclerosis. Here, we report that Sirtuin 1 (SIRT1), a protein deacetylase previously reported to have an antiinflammatory function, in fact promotes autoimmunity by deacetylating RORγt, the signature transcription factor of Th17 cells. SIRT1 increases RORγt transcriptional activity, enhancing Th17 cell generation and function. Both T cell–specific Sirt1 deletion and treatment with pharmacologic SIRT1 inhibitors suppress Th17 differentiation and are protective in a mouse model of multiple sclerosis. Moreover, analysis of infiltrating cell populations during disease induction in mixed hematopoietic chimeras shows a marked bias against Sirt1-deficient Th17 cells. These findings reveal an unexpected proinflammatory role of SIRT1 and, importantly, support the possible therapeutic use of SIRT1 inhibitors against autoimmunity.
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Affiliation(s)
- Hyung W Lim
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | - Seung Goo Kang
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Jae Kyu Ryu
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | | | - Mingjian Fei
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | - Intelly S Lee
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | | | - Kotaro Shirakawa
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | - Masaru Yokoyama
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | | | - Herbert G Kasler
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | - Hye-Sook Kwon
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | - Bradford W Gibson
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Buck Institute for Research on Aging, Novato, CA 94945
| | - Hironori Sato
- Laboratory of Viral Genomics, Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Katerina Akassoglou
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | - Changchun Xiao
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Dan R Littman
- Molecular Pathogenesis Program, The Kimmel Center for Biology and Medicine of the Skirball Institute, The Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016 Molecular Pathogenesis Program, The Kimmel Center for Biology and Medicine of the Skirball Institute, The Howard Hughes Medical Institute, New York University School of Medicine, New York, NY 10016
| | - Melanie Ott
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
| | - Eric Verdin
- Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158 Gladstone Institute of Virology and Immunology, Gladstone Institute of Neurological Disease, School of Medecine, Department of Neurology, Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158
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21
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Song W, Liang RP, Wang Y, Zhang L, Qiu JD. Green synthesis of peptide-templated gold nanoclusters as novel fluorescence probes for detecting protein kinase activity. Chem Commun (Camb) 2015; 51:10006-9. [DOI: 10.1039/c5cc02280k] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A green method was employed for synthesizing peptide-templated nanoclusters without requiring strong reducing agents. Using synthetic peptide–gold nanoclusters as fluorescence probes, a novel assay for detecting protein kinase is developed.
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Affiliation(s)
- Wei Song
- Department of Chemistry
- Nanchang University
- Nanchang 330031
- China
| | - Ru-Ping Liang
- Department of Chemistry
- Nanchang University
- Nanchang 330031
- China
| | - Ying Wang
- Department of Chemistry
- Nanchang University
- Nanchang 330031
- China
| | - Li Zhang
- Department of Chemistry
- Nanchang University
- Nanchang 330031
- China
| | - Jian-Ding Qiu
- Department of Chemistry
- Nanchang University
- Nanchang 330031
- China
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22
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Shandilya SMD, Bohn MF, Schiffer CA. A computational analysis of the structural determinants of APOBEC3's catalytic activity and vulnerability to HIV-1 Vif. Virology 2014; 471-473:105-16. [PMID: 25461536 PMCID: PMC4857191 DOI: 10.1016/j.virol.2014.09.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/29/2014] [Accepted: 09/30/2014] [Indexed: 11/23/2022]
Abstract
APOBEC3s (A3) are Zn(2+) dependent cytidine deaminases with diverse biological functions and implications for cancer and immunity. Four of the seven human A3s restrict HIV by 'hypermutating' the reverse-transcribed viral genomic DNA. HIV Virion Infectivity Factor (Vif) counters this restriction by targeting A3s to proteasomal degradation. However, there is no apparent correlation between catalytic activity, Vif binding, and sequence similarity between A3 domains. Our comparative structural analysis reveals features required for binding Vif and features influencing polynucleotide deaminase activity in A3 proteins. All Vif-binding A3s share a negatively charged surface region that includes residues previously implicated in binding the highly-positively charged Vif. Additionally, catalytically active A3s share a positively charged groove near the Zn(2+) coordinating active site, which may accommodate the negatively charged polynucleotide substrate. Our findings suggest surface electrostatics, as well as the spatial extent of substrate accommodating region, are critical determinants of substrate and Vif binding across A3 proteins with implications for anti-retroviral and anti-cancer therapeutic design.
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Affiliation(s)
- Shivender M D Shandilya
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Markus-Frederik Bohn
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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Desimmie BA, Delviks-Frankenberrry KA, Burdick RC, Qi D, Izumi T, Pathak VK. Multiple APOBEC3 restriction factors for HIV-1 and one Vif to rule them all. J Mol Biol 2014; 426:1220-45. [PMID: 24189052 PMCID: PMC3943811 DOI: 10.1016/j.jmb.2013.10.033] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/25/2013] [Accepted: 10/28/2013] [Indexed: 12/11/2022]
Abstract
Several members of the APOBEC3 family of cellular restriction factors provide intrinsic immunity to the host against viral infection. Specifically, APOBEC3DE, APOBEC3F, APOBEC3G, and APOBEC3H haplotypes II, V, and VII provide protection against HIV-1Δvif through hypermutation of the viral genome, inhibition of reverse transcription, and inhibition of viral DNA integration into the host genome. HIV-1 counteracts APOBEC3 proteins by encoding the viral protein Vif, which contains distinct domains that specifically interact with these APOBEC3 proteins to ensure their proteasomal degradation, allowing virus replication to proceed. Here, we review our current understanding of APOBEC3 structure, editing and non-editing mechanisms of APOBEC3-mediated restriction, Vif-APOBEC3 interactions that trigger APOBEC3 degradation, and the contribution of APOBEC3 proteins to restriction and control of HIV-1 replication in infected patients.
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Affiliation(s)
- Belete A Desimmie
- Viral Mutation Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | | | - Ryan C Burdick
- Viral Mutation Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - DongFei Qi
- Viral Mutation Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - Taisuke Izumi
- Viral Mutation Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, MD 21702, USA
| | - Vinay K Pathak
- Viral Mutation Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, MD 21702, USA.
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Singh M, Singh P, Vaira D, Torheim EA, Rahmouni S, Taskén K, Moutschen M. The RIAD peptidomimetic inhibits HIV-1 replication in humanized NSG mice. Eur J Clin Invest 2014; 44:146-52. [PMID: 24283208 DOI: 10.1111/eci.12200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 11/03/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Increased intracellular concentration of cyclic AMP (cAMP) in T cells is associated with various immunodeficiency conditions including human immunodeficiency virus (HIV) infection. Several reports indicate a critical role of activated protein kinase A (PKA) in the susceptibility of cells to HIV infection. We have used a cell permeable, stable peptidomimetic version (P3) of the RI-anchoring disruptor (RIAD), which prevents PKA interaction with A-kinase-anchoring proteins (AKAPs). It is known that RIAD peptide abrogates effects of localized cAMP signalling through anchored type I PKA in lymphocytes and prevents murine AIDS (MAIDS) infection when expressed as a transgene in mice. METHODS AND RESULTS In vitro HIV-infected human peripheral blood mononuclear cells (PBMCs) show reduced levels of p24 and intracellular cAMP in T cells when treated with RIAD peptidomimetic (RIAD-P3). Humanized NOD/SCID/IL2γnull (NSG) mice infected with HIV-1 JRCSF and treated with RIAD-P3 (3·5 mg) once every 2 weeks showed significantly reduced levels of viral load at +28, +42 and +56 days and increased CD4 numbers at +56 days after the start of treatment. RIAD-P3-treated humanized mice had lower levels of intracellular cAMP in T cells sorted from splenocytes. CONCLUSIONS Treatment with RIAD-P3 limits HIV-1 viral replication and stabilizes CD4 levels by mechanisms involving cAMP/PKA-I pathway in human PBMCs and humanized NSG mice.
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Affiliation(s)
- Maneesh Singh
- Immunology & Infectious Diseases, CHU de Liège, Université de Liège, Liège, Belgium
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25
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Abstract
UNLABELLED Many murine leukemia viruses (MLVs) are partially resistant to restriction by mouse APOBEC3 (mA3) and essentially fully resistant to induction of G-to-A mutations by mA3. In contrast, Vif-deficient HIV-1 (ΔVif HIV-1) is profoundly restricted by mA3, and the restriction includes high levels of G-to-A mutation. Human APOBEC3G (hA3G), unlike mA3, is fully active against MLVs. We produced a glutathione S-transferase-mA3 fusion protein in insect cells and demonstrated that it possesses cytidine deaminase activity, as expected. This activity is localized within the N-terminal domain of this 2-domain protein; the C-terminal domain is enzymatically inactive but required for mA3 encapsidation into retrovirus particles. We found that a specific arginine residue and several aromatic residues, as well as the zinc-coordinating cysteines in the C-terminal domain, are necessary for mA3 packaging; a structural model of this domain suggests that these residues line a potential nucleic acid-binding interface. Mutation of a few potential phosphorylation sites in mA3 drastically reduces its antiviral activity by impairing either deaminase activity or its encapsidation. mA3 deaminates short single-stranded DNA oligonucleotides preferentially toward their 3' ends, whereas hA3G exhibits the opposite polarity. However, when packaged into infectious ΔVif HIV-1 virions, both mA3 and hA3G preferentially induce deaminations toward the 5' end of minus-strand viral DNA, presumably because of the sequence of events during reverse transcription in vivo. Despite the fact that mA3 in MLV particles does not induce detectable deaminations upon infection, its deaminase activity is easily detected in virus lysates. We still do not understand how MLV resists mA3-induced G-to-A mutation. IMPORTANCE One way that mammalian cells defend themselves against infection by retroviruses is with APOBEC3 proteins. These proteins convert cytidine bases to uridine bases in retroviral DNA. However, mouse APOBEC3 protein blocks infection by murine leukemia viruses without catalyzing this base change, and the mechanism of inhibition is not understood in this case. We have produced recombinant mouse APOBEC3 protein for the first time and characterized it here in a number of ways. Our mutational studies shed light on the mechanism by which mouse APOBEC3 protein is incorporated into retrovirus particles. While mouse APOBEC3 does not catalyze base changes in murine leukemia virus DNA, it can be recovered from these virus particles in enzymatically active form; it is still not clear why it fails to induce base changes when these viruses infect new cells.
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APOBEC3G oligomerization is associated with the inhibition of both Alu and LINE-1 retrotransposition. PLoS One 2013; 8:e84228. [PMID: 24367644 PMCID: PMC3868573 DOI: 10.1371/journal.pone.0084228] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 11/20/2013] [Indexed: 11/19/2022] Open
Abstract
Alu and LINE-1 (L1), which constitute ~11% and ~17% of the human genome, respectively, are transposable non-LTR retroelements. They transpose not only in germ cells but also in somatic cells, occasionally causing cancer. We have previously demonstrated that antiretroviral restriction factors, human APOBEC3 (hA3) proteins (A–H), differentially inhibit L1 retrotransposition. In this present study, we found that hA3 members also restrict Alu retrotransposition at differential levels that correlate with those observed previously for L1 inhibition. Through deletion analyses based on the best-characterized hA3 member human APOBEC3G (hA3G), its N-terminal 30 amino acids were required for its inhibitory activity against Alu retrotransposition. The inhibitory effect of hA3G on Alu retrotransposition was associated with its oligomerization that was affected by the deletion of its N-terminal 30 amino acids. Through structural modeling, the amino acids 24 to 28 of hA3G were predicted to be located at the interface of the dimer. The mutation of these residues resulted in abrogated hA3G oligomerization, and consistently abolished the inhibitory activity of hA3G against Alu retrotransposition. Importantly, the anti-L1 activity of hA3G was also associated with hA3G oligomerization. These results suggest that the inhibitory activities of hA3G against Alu and L1 retrotransposition might involve a common mechanism.
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Giroud C, Chazal N, Gay B, Eldin P, Brun S, Briant L. HIV-1-associated PKA acts as a cofactor for genome reverse transcription. Retrovirology 2013; 10:157. [PMID: 24344931 PMCID: PMC3880072 DOI: 10.1186/1742-4690-10-157] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 12/02/2013] [Indexed: 11/15/2022] Open
Abstract
Background Host cell proteins, including cellular kinases, are embarked into intact HIV-1 particles. We have previously shown that the Cα catalytic subunit of cAMP-dependent protein kinase is packaged within HIV-1 virions as an enzymatically active form able to phosphorylate a synthetic substrate in vitro (Cartier et al. J. Biol. Chem. 278:35211 (2003)). The present study was conceived to investigate the contribution of HIV-1-associated PKA to the retroviral life cycle. Results NL4.3 viruses were produced from cells cultured in the presence of PKA inhibitors H89 (H89-NL4.3) or Myr-PKI (PKI-NL4.3) and analyzed for viral replication. Despite being mature and normally assembled, and containing expected levels of genomic RNA and RT enzymatic activity, such viruses showed poor infectivity. Indeed, infection generated reduced amounts of strong-strop minus strand DNA, while incoming RNA levels in target cells were unaffected. Decreased cDNA synthesis was also evidenced in intact H89-NL4.3 and PKI-NL4.3 cell free particles using endogenous reverse transcription (ERT) experiments. Moreover, similar defects were reproduced when wild type NL4.3 particles preincubated with PKA inhibitors were subjected to ERT reactions. Conclusions Altogether, our results indicate that HIV-1-associated PKA is required for early reverse transcription of the retroviral genome both in cell free intact viruses and in target cells. Accordingly, virus-associated PKA behaves as a cofactor of an intraviral process required for optimal reverse transcription and for early post-entry events.
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Affiliation(s)
| | | | | | | | | | - Laurence Briant
- Centre d'étude d'agents Pathogènes et Biotechnologies pour la Santé (CPBS)-CNRS UMR 5236, Université Montpellier 1,2, 1919 route de Mende, Montpellier, cedex 2 34293, France.
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Mov10 and APOBEC3G localization to processing bodies is not required for virion incorporation and antiviral activity. J Virol 2013; 87:11047-62. [PMID: 23926332 DOI: 10.1128/jvi.02070-13] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mov10 and APOBEC3G (A3G) localize to cytoplasmic granules called processing bodies (P bodies), incorporate into human immunodeficiency virus type 1 (HIV-1) virions, and inhibit viral replication. The functional relevance of Mov10/A3G P-body localization to virion incorporation and antiviral activity has not been fully explored. We found that a helicase V mutant of Mov10 exhibits significantly reduced localization to P bodies but still efficiently inhibits viral infectivity via virion incorporation. Disruption of the P bodies by DDX6 knockdown also confirmed Mov10 antiviral activity without P-body localization. In addition, overexpression of SRP19, which binds to 7SL RNA, depleted A3G from P bodies but did not affect its virion incorporation. Sucrose gradient sedimentation assays revealed that the majority of Mov10, A3G, HIV-1 RNA, and Gag formed high-molecular-mass (HMM) complexes that are converted to low-molecular-mass (LMM) complexes after RNase A treatment. In contrast, the P-body markers DCP2, LSM1, eIF4e, DDX6, and AGO1 were in LMM complexes, whereas AGO2, an effector protein of the RNA-induced silencing complex that localizes to P bodies, was present in both LMM and HMM complexes. Depletion of AGO2 indicated that RNA-induced silencing function is required for Mov10's ability to reduce Gag expression upon overexpression, but not its virion incorporation or effect on virus infectivity. We conclude that the majority of Mov10 and A3G are in HMM complexes, whereas most of the P-body markers are in LMM complexes, and that virion incorporation and the antiviral activities of Mov10 and A3G do not require their localization to P bodies.
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Singhroy DN, Mesplède T, Sabbah A, Quashie PK, Falgueyret JP, Wainberg MA. Automethylation of protein arginine methyltransferase 6 (PRMT6) regulates its stability and its anti-HIV-1 activity. Retrovirology 2013; 10:73. [PMID: 23866860 PMCID: PMC3750301 DOI: 10.1186/1742-4690-10-73] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 07/09/2013] [Indexed: 01/10/2023] Open
Abstract
Background Protein arginine methyltransferase 6 (PRMT6) is a nuclear enzyme that methylates arginine residues on histones and transcription factors. In addition, PRMT6 inhibits HIV-1 replication in cell culture by directly methylating and interfering with the functions of several HIV-1 proteins, i.e. Tat, Rev and nucleocapsid (NC). PRMT6 also displays automethylation capacity but the role of this post-translational modification in its antiretroviral activity remains unknown. Results Here we report the identification by liquid chromatography-mass spectrometry of R35 within PRMT6 as the target residue for automethylation and have confirmed this by site-directed mutagenesis and in vitro and in vivo methylation assays. We further show that automethylation at position 35 greatly affects PRMT6 stability and is indispensable for its antiretroviral activity, as demonstrated in HIV-1 single-cycle TZM-bl infectivity assays. Conclusion These results show that PRMT6 automethylation plays a role in the stability of this protein and that this event is indispensible for its anti-HIV-1 activity.
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Affiliation(s)
- Diane N Singhroy
- McGill University AIDS Centre, Lady Davis for Medical Research, Jewish General Hospital, 3755 Cote Sainte Catherine, Montreal, QC, H3T 1E2, Canada
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Takaori-Kondo A, Shindo K. HIV-1 Vif: a guardian of the virus that opens up a new era in the research field of restriction factors. Front Microbiol 2013; 4:34. [PMID: 23430691 PMCID: PMC3576844 DOI: 10.3389/fmicb.2013.00034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 02/07/2013] [Indexed: 11/13/2022] Open
Abstract
The research on virion infectivity factor (Vif) protein had started in late 1980s right after HIV-1 was cloned, and the function of Vif had been a mystery for a long time. However, the research on Vif has finally lead to the identification of APOBEC3G, which opens up a new era in the research field of host restriction factors in HIV-1 infection followed by TRIM5α, Tetherin/BST-2, and SAMHD1. This suggests that continuation of basic research on fundamental questions is quite important. We still have many questions on Vif and APOBEC3 and should continue to work on these proteins in the future in order to better regulate HIV-1. We will discuss not only the history but also recent advances in Vif research.
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Affiliation(s)
- Akifumi Takaori-Kondo
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University Kyoto, Japan
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31
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Shinohara M, Io K, Shindo K, Matsui M, Sakamoto T, Tada K, Kobayashi M, Kadowaki N, Takaori-Kondo A. APOBEC3B can impair genomic stability by inducing base substitutions in genomic DNA in human cells. Sci Rep 2012; 2:806. [PMID: 23150777 PMCID: PMC3496164 DOI: 10.1038/srep00806] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 10/10/2012] [Indexed: 12/20/2022] Open
Abstract
Human APOBEC3 proteins play pivotal roles in intracellular defense against viral infection by catalyzing deamination of cytidine residues, leading to base substitutions in viral DNA. Activation-induced cytidine deaminase (AID), another member of the APOBEC family, is capable of editing immunoglobulin (Ig) and non-Ig genes, and aberrant expression of AID leads to tumorigenesis. However, it remains unclear whether APOBEC3 (A3) proteins affect stability of human genome. Here we demonstrate that both A3A and A3B can induce base substitutions into human genome as AID can. A3B is highly expressed in several lymphoma cells and somatic mutations occur in some oncogenes of the cells highly expressing A3B. Furthermore, transfection of A3B gene into lymphoma cells induces base substitutions in cMYC gene. These data suggest that aberrant expression of A3B can evoke genomic instability by inducing base substitutions into human genome, which might lead to tumorigenesis in human cells.
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Affiliation(s)
- Masanobu Shinohara
- Department of Hematology and Oncology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Fujisaki S, Takashita E, Yokoyama M, Taniwaki T, Xu H, Kishida N, Sato H, Tashiro M, Imai M, Odagiri T. A single E105K mutation far from the active site of influenza B virus neuraminidase contributes to reduced susceptibility to multiple neuraminidase-inhibitor drugs. Biochem Biophys Res Commun 2012; 429:51-6. [PMID: 23131559 DOI: 10.1016/j.bbrc.2012.10.095] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 10/24/2012] [Indexed: 11/28/2022]
Abstract
Drugs inhibiting the enzymatic activity of influenza virus neuraminidase (NA) are the cornerstone of therapy for influenza virus infection. The emergence of drug-resistant variants may limit the benefits of antiviral therapy. Here we report the recovery of an influenza B virus with reduced susceptibilities to NA inhibitors from a human patient with no history of antiviral drug treatment. The virus, designated B/Kochi/61/2011, was isolated by inoculating Madin-Darby canine kidney (MDCK) cells with respiratory specimens from the patient. NA inhibition assays demonstrated that the B/Kochi/61/2011 isolate showed a remarkable reduction in susceptibility to peramivir. The isolate also exhibited low to moderately reduced sensitivity to oseltamivir, laninamivir, and zanamivir. A sequence analysis of viruses propagated in MDCK cells revealed that the isolate contained a mutation (E105K) not previously associated with reduced susceptibility to NA inhibitors. However, pyrosequencing analysis showed that the NA E105K mutation was below a detectable level in the original clinical specimens, suggesting that the mutant virus may be preferably selected during propagation in MDCK cells. Analysis of the three-dimensional model of E105 and K105 NAs with peramivir suggested that the E105K mutation at the monomer-monomer interface of the NA tetramer may destabilize the tetrameric form of NA, leading to decreased susceptibility to NA inhibitors. These results have implications for understanding the mechanism of resistance against NA-inhibitor drugs.
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Affiliation(s)
- Seiichiro Fujisaki
- Laboratory of Influenza Virus Surveillance, Influenza Virus Research Center, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
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Yokoyama M, Oka T, Kojima H, Nagano T, Okabe T, Katayama K, Wakita T, Kanda T, Sato H. Structural basis for specific recognition of substrates by sapovirus protease. Front Microbiol 2012; 3:312. [PMID: 22973264 PMCID: PMC3433708 DOI: 10.3389/fmicb.2012.00312] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 08/08/2012] [Indexed: 01/31/2023] Open
Abstract
Sapovirus (SaV) protease catalyzes cleavage of the peptide bonds at six sites of a viral polyprotein for the viral replication and maturation. However, the mechanisms by which the protease recognizes the distinct sequences of the six cleavage sites remain poorly understood. Here we examined this issue by computational and experimental approaches. A structural modeling and docking study disclosed two small clefts on the SaV protease cavity that allow the stable and functional binding of substrates to the catalytic cavity via aromatic stacking and electrostatic interactions. An information entropy study and a site-directed mutagenesis study consistently suggested variability of the two clefts under functional constraints. Using this information, we identified three chemical compounds that had structural and spatial features resembling those of the substrate amino acid residues bound to the two clefts and that exhibited an inhibitory effect on SaV protease in vitro. These results suggest that the two clefts provide structural base points to realize the functional binding of various substrates.
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Affiliation(s)
- Masaru Yokoyama
- Pathogen Genomics Center, National Institute of Infectious Diseases Tokyo, Japan
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34
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Kopietz F, Jaguva Vasudevan AA, Krämer M, Muckenfuss H, Sanzenbacher R, Cichutek K, Flory E, Münk C. Interaction of human immunodeficiency virus type 1 Vif with APOBEC3G is not dependent on serine/threonine phosphorylation status. J Gen Virol 2012; 93:2425-2430. [PMID: 22894923 DOI: 10.1099/vir.0.043273-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The human immunodeficiency virus type 1 accessory protein Vif is important for viral infectivity because it counteracts the antiviral protein APOBEC3G (A3G). ³²P metabolic labelling of stimulated cells revealed in vivo phosphorylation of the control protein, whereas no serine/threonine phosphorylation was detected for Vif or the A3G protein. These data were confirmed by in vitro kinase assays using active recombinant kinase. Mitogen-activated protein kinase/extracellular signal-regulated kinase 2 efficiently phosphorylated its target ELK, but failed to phosphorylate Vif. Putative serine/threonine phosphorylation point mutations in Vif (T96, S144, S165, T188) using single-round infection assays demonstrated that these mutations did not alter Vif activity, with the exception of Vif.T96E. Interestingly, T96E and not T96A was functionally impaired, indicating that this residue is critical for Vif-A3G physical interaction and activity. Our data suggest that Vif and A3G are not serine/threonine phosphorylated in human cells and phosphorylation is not linked to their functional activities.
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Affiliation(s)
- Ferdinand Kopietz
- Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany
| | | | - Melanie Krämer
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Heide Muckenfuss
- Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany
| | - Ralf Sanzenbacher
- Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany
| | - Klaus Cichutek
- Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany
| | - Egbert Flory
- Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
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Evaluation of influenza virus A/H3N2 and B vaccines on the basis of cross-reactivity of postvaccination human serum antibodies against influenza viruses A/H3N2 and B isolated in MDCK cells and embryonated hen eggs. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:897-908. [PMID: 22492743 DOI: 10.1128/cvi.05726-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The vaccine strains against influenza virus A/H3N2 for the 2010-2011 season and influenza virus B for the 2009-2010 and 2010-2011 seasons in Japan are a high-growth reassortant A/Victoria/210/2009 (X-187) strain and an egg-adapted B/Brisbane/60/2008 (Victoria lineage) strain, respectively. Hemagglutination inhibition (HI) tests with postinfection ferret antisera indicated that the antisera raised against the X-187 and egg-adapted B/Brisbane/60/2008 vaccine production strains poorly inhibited recent epidemic isolates of MDCK-grown A/H3N2 and B/Victoria lineage viruses, respectively. The low reactivity of the ferret antisera may be attributable to changes in the hemagglutinin (HA) protein of production strains during egg adaptation. To evaluate the efficacy of A/H3N2 and B vaccines, the cross-reactivities of postvaccination human serum antibodies against A/H3N2 and B/Victoria lineage epidemic isolates were assessed by a comparison of the geometric mean titers (GMTs) of HI and neutralization (NT) tests. Serum antibodies elicited by the X-187 vaccine had low cross-reactivity to both MDCK- and egg-grown A/H3N2 isolates by HI test and narrow cross-reactivity by NT test in all age groups. On the other hand, the GMTs to B viruses detected by HI test were below the marginal level, so the cross-reactivity was assessed by NT test. The serum neutralizing antibodies elicited by the B/Brisbane/60/2008 vaccine reacted well with egg-grown B viruses but exhibited remarkably low reactivity to MDCK-grown B viruses. The results of these human serological studies suggest that the influenza A/H3N2 vaccine for the 2010-2011 season and B vaccine for the 2009-2010 and 2010-2011 seasons may possess insufficient efficacy and low efficacy, respectively.
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36
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Biard-Piechaczyk M, Borel S, Espert L, de Bettignies G, Coux O. HIV-1, ubiquitin and ubiquitin-like proteins: the dialectic interactions of a virus with a sophisticated network of post-translational modifications. Biol Cell 2012; 104:165-87. [PMID: 22188301 DOI: 10.1111/boc.201100112] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 12/14/2011] [Indexed: 11/26/2022]
Abstract
The modification of intracellular proteins by ubiquitin (Ub) and ubiquitin-like (UbL) proteins is a central mechanism for regulating and fine-tuning all cellular processes. Indeed, these modifications are widely used to control the stability, activity and localisation of many key proteins and, therefore, they are instrumental in regulating cellular functions as diverse as protein degradation, cell signalling, vesicle trafficking and immune response. It is thus no surprise that pathogens in general, and viruses in particular, have developed multiple strategies to either counteract or exploit the complex mechanisms mediated by the Ub and UbL protein conjugation pathways. The aim of this review is to provide an overview on the intricate and conflicting relationships that intimately link HIV-1 and these sophisticated systems of post-translational modifications.
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Affiliation(s)
- Martine Biard-Piechaczyk
- Centre d'étude d'agents Pathogènes et Biotechnologies pour la Santé (CPBS-CNRS), Montpellier Cedex 5, France.
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37
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Narvaiza I, Landry S, Weitzman MD. APOBEC3 proteins and genomic stability: the high cost of a good defense. Cell Cycle 2012; 11:33-8. [PMID: 22157092 PMCID: PMC3272230 DOI: 10.4161/cc.11.1.18706] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 11/07/2011] [Accepted: 11/08/2011] [Indexed: 01/07/2023] Open
Abstract
The human APOBEC3 family of cytidine deaminases constitutes a cellular intrinsic defense mechanism that is effective against a range of viruses and retro-elements. While it is well established that these enzymes are powerful mutators of viral DNA, the possibility that their activity could threaten the integrity of the host genome has only recently begun to be investigated. Here, we discuss the implications of new evidence suggesting that APOBEC3 proteins can mediate the deamination of cellular DNA. The maintenance of genomic integrity in the face of this potential off-target activity must require high fidelity DNA repair and strict regulation of APOBEC3 gene expression and enzyme activity. Conversely, the ability of specific members of the APOBEC3 family to activate DNA damage signaling pathways might also reflect another way that these proteins contribute to the host immune response.
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Affiliation(s)
- Iñigo Narvaiza
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA
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Shimoda Y, Han L, Yamazaki T, Suzuki R, Hayashi M, Imaizumi-Anraku H. Rhizobial and fungal symbioses show different requirements for calmodulin binding to calcium calmodulin-dependent protein kinase in Lotus japonicus. THE PLANT CELL 2012; 24:304-21. [PMID: 22253228 PMCID: PMC3289572 DOI: 10.1105/tpc.111.092197] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/05/2011] [Accepted: 12/15/2011] [Indexed: 05/18/2023]
Abstract
Ca(2+)/calmodulin (CaM)-dependent protein kinase (CCaMK) is a key regulator of root nodule and arbuscular mycorrhizal symbioses and is believed to be a decoder for Ca(2+) signals induced by microbial symbionts. However, it is unclear how CCaMK is activated by these microbes. Here, we investigated in vivo activation of CCaMK in symbiotic signaling, focusing mainly on the significance of and epistatic relationships among functional domains of CCaMK. Loss-of-function mutations in EF-hand motifs revealed the critical importance of the third EF hand for CCaMK activation to promote infection of endosymbionts. However, a gain-of-function mutation (T265D) in the kinase domain compensated for these loss-of-function mutations in the EF hands. Mutation of the CaM binding domain abolished CaM binding and suppressed CCaMK(T265D) activity in rhizobial infection, but not in mycorrhization, indicating that the requirement for CaM binding to CCaMK differs between root nodule and arbuscular mycorrhizal symbioses. Homology modeling and mutagenesis studies showed that the hydrogen bond network including Thr265 has an important role in the regulation of CCaMK. Based on these genetic, biochemical, and structural studies, we propose an activation mechanism of CCaMK in which root nodule and arbuscular mycorrhizal symbioses are distinguished by differential regulation of CCaMK by CaM binding.
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Affiliation(s)
- Yoshikazu Shimoda
- Division of Plant Sciences, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Lu Han
- Division of Plant Sciences, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Toshimasa Yamazaki
- Agrogenomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Rintaro Suzuki
- Agrogenomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Makoto Hayashi
- Division of Plant Sciences, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
| | - Haruko Imaizumi-Anraku
- Division of Plant Sciences, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan
- Address correspondence to
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39
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Kitamura S, Ode H, Iwatani Y. Structural Features of Antiviral APOBEC3 Proteins are Linked to Their Functional Activities. Front Microbiol 2011; 2:258. [PMID: 22203821 PMCID: PMC3243911 DOI: 10.3389/fmicb.2011.00258] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 12/02/2011] [Indexed: 11/23/2022] Open
Abstract
Human APOBEC3 (A3) proteins are cellular cytidine deaminases that potently restrict the replication of retroviruses by hypermutating viral cDNA and/or inhibiting reverse transcription. There are seven members of this family including A3A, B, C, DE, F, G, and H, all encoded in a tandem array on human chromosome 22. A3F and A3G are the most potent inhibitors of HIV-1, but only in the absence of the virus-encoded protein, Vif. HIV-1 utilizes Vif to abrogate A3 functions in the producer cells. More specifically, Vif, serving as a substrate receptor, facilitates ubiquitination of A3 proteins by forming a Cullin5 (Cul5)-based E3 ubiquitin ligase complex, which targets A3 proteins for rapid proteasomal degradation. The specificity of A3 degradation is determined by the ability of Vif to bind to the target. Several lines of evidence have suggested that three distinct regions of A3 proteins are involved in the interaction with Vif. Here, we review the biological functions of A3 family members with special focus on A3G and base our analysis on the available structural information.
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Affiliation(s)
- Shingo Kitamura
- Laboratory of Infectious Diseases, Department of Infectious Diseases and Immunology, Clinical Research Center, National Hospital Organization Nagoya Medical Center Nagoya, Japan
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40
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Chutiwitoonchai N, Hiyoshi M, Mwimanzi P, Ueno T, Adachi A, Ode H, Sato H, Fackler OT, Okada S, Suzu S. The identification of a small molecule compound that reduces HIV-1 Nef-mediated viral infectivity enhancement. PLoS One 2011; 6:e27696. [PMID: 22110726 PMCID: PMC3217016 DOI: 10.1371/journal.pone.0027696] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 10/22/2011] [Indexed: 12/14/2022] Open
Abstract
Nef is a multifunctional HIV-1 protein that accelerates progression to AIDS, and enhances the infectivity of progeny viruses through a mechanism that is not yet understood. Here, we show that the small molecule compound 2c reduces Nef-mediated viral infectivity enhancement. When added to viral producer cells, 2c did not affect the efficiency of viral production itself. However, the infectivity of the viruses produced in the presence of 2c was significantly lower than that of control viruses. Importantly, an inhibitory effect was observed with Nef(+) wild-type viruses, but not with viruses produced in the absence of Nef or in the presence of proline-rich PxxP motif-disrupted Nef, both of which displayed significantly reduced intrinsic infectivity. Meanwhile, the overexpression of the SH3 domain of the tyrosine kinase Hck, which binds to a PxxP motif in Nef, also reduced viral infectivity. Importantly, 2c inhibited Hck SH3-Nef binding, which was more marked when Nef was pre-incubated with 2c prior to its incubation with Hck, indicating that both Hck SH3 and 2c directly bind to Nef and that their binding sites overlap. These results imply that both 2c and the Hck SH3 domain inhibit the interaction of Nef with an unidentified host protein and thereby reduce Nef-mediated infectivity enhancement. The first inhibitory compound 2c is therefore a valuable chemical probe for revealing the underlying molecular mechanism by which Nef enhances the infectivity of HIV-1.
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Affiliation(s)
| | | | - Philip Mwimanzi
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Takamasa Ueno
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Akio Adachi
- Department of Microbiology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Hirotaka Ode
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hironori Sato
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Oliver T. Fackler
- Department of Infectious Diseases, Virology, University of Heidelberg, Heidelberg, Germany
| | - Seiji Okada
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
| | - Shinya Suzu
- Center for AIDS Research, Kumamoto University, Kumamoto, Japan
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41
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[Bioinformatics studies on drug resistance against anti-HIV-1 drugs]. Uirusu 2011; 61:35-47. [PMID: 21972554 DOI: 10.2222/jsv.61.35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
More than 20 drugs have been available for anti-HIV-1 treatment in Japan. Combination therapy with these drugs dramatically decreases in morbidity and mortality of AIDS. However, due to high mutation rate of HIV-1, treatment with ineffective drugs toward patients infected with HIV-1 causes accumulation of mutations in the virus, and emergence of drug resistant viruses. Thus, to achieve appropriate application of the drugs toward the respective patients living with HIV-1, methods for predicting the level of drug-resistance using viral sequence information has been developed on the basis of bioinformatics. Furthermore, ultra-deep sequencing by next-generation sequencer whose data analysis is also based on bioinformatics, or in silico structural modeling have been achieved to understand drug resistant mechanisms. In this review, I overview the bioinformatics studies about drug resistance against anti-HIV-1 drugs.
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[Structural mechanism of immune evasion of HIV-1 gp120 by genomic, computational, and experimental science]. Uirusu 2011; 61:49-57. [PMID: 21972555 DOI: 10.2222/jsv.61.49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The third variable region (V3) of the human immunodeficiency virus type 1 (HIV-1) envelope gp120 subunit participates in determination of viral infection co-receptor tropism and host humoral immune responses. Positive charge of the V3 plays a key role in determining viral co-receptor tropism. In our previous papers, we showed a key role of the V3's net positive charge in the immunological escape and co-receptor tropism evolution in vivo. On the other hand, the several papers suggested that trimeric gp120s are protected from immune system by occlusion on the oligomer, by mutational variation, by carbohydrate masking and by conformational masking. If we can reveal the mechanism of neutralization escape, we expect that we will regulate the neutralization of HIV-1. In this review, we will overview the structural mechanism of neutralization escape of HIV-1 gp120 examined by computational science. The computational sciences for virology can provide more valuable information in combination with genomic and experimental science.
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Miyamoto T, Yokoyama M, Kono K, Shioda T, Sato H, Nakayama EE. A single amino acid of human immunodeficiency virus type 2 capsid protein affects conformation of two external loops and viral sensitivity to TRIM5α. PLoS One 2011; 6:e22779. [PMID: 21829511 PMCID: PMC3145752 DOI: 10.1371/journal.pone.0022779] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 07/07/2011] [Indexed: 11/18/2022] Open
Abstract
We previously reported that human immunodeficiency virus type 2 (HIV-2) carrying alanine or glutamine but not proline at position 120 of the capsid protein (CA) could grow in the presence of anti-viral factor TRIM5α of cynomolgus monkey (CM). To elucidate details of the interaction between the CA and TRIM5α, we generated mutant HIV-2 viruses, each carrying one of the remaining 17 possible amino acid residues, and examined their sensitivity to CM TRIM5α-mediated restriction. Results showed that hydrophobic residues or those with ring structures were associated with sensitivity, while those with small side chains or amide groups conferred resistance. Molecular dynamics simulation study revealed a structural basis for the differential TRIM5α sensitivities. The mutations at position 120 in the loop between helices 6 and 7 (L6/7) affected conformation of the neighboring loop between helices 4 and 5 (L4/5), and sensitive viruses had a common L4/5 conformation. In addition, the common L4/5 structures of the sensitive viruses were associated with a decreased probability of hydrogen bond formation between the 97th aspartic acid in L4/5 and the 119th arginine in L6/7. When we introduced aspartic acid-to-alanine substitution at position 97 (D97A) of the resistant virus carrying glutamine at position 120 to disrupt hydrogen bond formation, the resultant virus became moderately sensitive. Interestingly, the virus carrying glutamic acid at position 120 showed resistance, while its predicted L4/5 conformation was similar to those of sensitive viruses. The D97A substitution failed to alter the resistance of this particular virus, indicating that the 120th amino acid residue itself is also involved in sensitivity regardless of the L4/5 conformation. These results suggested that a hydrogen bond between the L4/5 and L6/7 modulates the overall structure of the exposed surface of the CA, but the amino acid residue at position 120 is also directly involved in CM TRIM5α recognition.
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Affiliation(s)
- Tadashi Miyamoto
- Department of Viral infections, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Masaru Yokoyama
- Pathogen Genomics Center, National Institute of Infectious Diseases, Musashi Murayama, Tokyo, Japan
| | - Ken Kono
- Department of Viral infections, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- Research Fellow of the Japan Society for the Promotion of Science, Tokyo, Japan
| | - Tatsuo Shioda
- Department of Viral infections, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Hironori Sato
- Pathogen Genomics Center, National Institute of Infectious Diseases, Musashi Murayama, Tokyo, Japan
| | - Emi E. Nakayama
- Department of Viral infections, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- * E-mail:
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Demorest ZL, Li M, Harris RS. Phosphorylation directly regulates the intrinsic DNA cytidine deaminase activity of activation-induced deaminase and APOBEC3G protein. J Biol Chem 2011; 286:26568-75. [PMID: 21659520 DOI: 10.1074/jbc.m111.235721] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The beneficial effects of DNA cytidine deamination by activation-induced deaminase (AID; antibody gene diversification) and APOBEC3G (retrovirus restriction) are tempered by probable contributions to carcinogenesis. Multiple regulatory mechanisms serve to minimize this detrimental outcome. Here, we show that phosphorylation of a conserved threonine attenuates the intrinsic activity of activation-induced deaminase (Thr-27) and APOBEC3G (Thr-218). Phospho-null alanine mutants maintain intrinsic DNA deaminase activity, whereas phospho-mimetic glutamate mutants are inactive. The phospho-mimetic variants fail to mediate isotype switching in activated mouse splenic B lymphocytes or suppress HIV-1 replication in human T cells. Our data combine to suggest a model in which this critical threonine acts as a phospho-switch that fine-tunes the adaptive and innate immune responses and helps protect mammalian genomic DNA from procarcinogenic lesions.
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Affiliation(s)
- Zachary L Demorest
- Department of Biochemistry, Molecular Biology, and Biophysics, Institute for Molecular Virology, and Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Within-host co-evolution of Gag P453L and protease D30N/N88D demonstrates virological advantage in a highly protease inhibitor-exposed HIV-1 case. Antiviral Res 2011; 90:33-41. [PMID: 21338625 DOI: 10.1016/j.antiviral.2011.02.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 12/28/2010] [Accepted: 02/11/2011] [Indexed: 11/22/2022]
Abstract
To better understand the mechanism of HIV group-specific antigen (Gag) and protease (PR) co-evolution in drug-resistance acquisition, we analyzed a drug-resistance case by both bioinformatics and virological methods. We especially considered the quality of sequence data and analytical accuracy by introducing single-genome sequencing (SGS) and Spidermonkey/Bayesian graphical models (BGM) analysis, respectively. We analyzed 129 HIV-1 Gag-PR linkage sequences obtained from 8 time points, and the resulting sequences were applied to the Spidermonkey co-evolution analysis program, which identified ten mutation pairs as significantly co-evolving. Among these, we focused on associations between Gag-P453L, the P5' position of the p1/p6 cleavage-site mutation, and PR-D30N/N88D nelfinavir-resistant mutations, and attempted to clarify their virological significance in vitro by constructing recombinant clones. The results showed that P453L(Gag) has the potential to improve replication capacity and the Gag processing efficiency of viruses with D30N(PR)/N88D(PR) but has little effect on nelfinavir susceptibility. Homology modeling analysis suggested that hydrogen bonds between the 30th PR residue and the R452Gag are disturbed by the D30N(PR) mutation, but the impaired interaction is compensated by P453L(Gag) generating new hydrophobic interactions. Furthermore, database analysis indicated that the P453L(Gag)/D30N(PR)/N88D(PR) association was not specific only to our clinical case, but was common among AIDS patients.
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Inagaki N, Takeuchi H, Yokoyama M, Sato H, Ryo A, Yamamoto H, Kawada M, Matano T. A structural constraint for functional interaction between N-terminal and C-terminal domains in simian immunodeficiency virus capsid proteins. Retrovirology 2010; 7:90. [PMID: 20955553 PMCID: PMC2964592 DOI: 10.1186/1742-4690-7-90] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 10/18/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Gag capsid (CA) is one of the most conserved proteins in highly-diversified human and simian immunodeficiency viruses (HIV and SIV). Understanding the limitations imposed on amino acid sequences in CA could provide valuable information for vaccine immunogen design or anti-HIV drug development. Here, by comparing two pathogenic SIV strains, SIVmac239 and SIVsmE543-3, we found critical amino acid residues for functional interaction between the N-terminal and the C-terminal domains in CA. RESULTS We first examined the impact of Gag residue 205, aspartate (Gag205D) in SIVmac239 and glutamate (Gag205E) in SIVsmE543-3, on viral replication; due to this difference, Gag206-216 (IINEEAADWDL) epitope-specific cytotoxic T lymphocytes (CTLs) were previously shown to respond to SIVmac239 but not SIVsmE543-3 infection. A mutant SIVmac239, SIVmac239Gag205E, whose Gag205D is replaced with Gag205E showed lower replicative ability. Interestingly, however, SIVmac239Gag205E passaged in macaque T cell culture often resulted in selection of an additional mutation at Gag residue 340, a change from SIVmac239 valine (Gag340V) to SIVsmE543-3 methionine (Gag340M), with recovery of viral fitness. Structural modeling analysis suggested possible intermolecular interaction between the Gag205 residue in the N-terminal domain and Gag340 in the C-terminal in CA hexamers. The Gag205D-to-Gag205E substitution in SIVmac239 resulted in loss of in vitro core stability, which was recovered by additional Gag340V-to-Gag340M substitution. Finally, selection of Gag205E plus Gag340M mutations, but not Gag205E alone was observed in a chronically SIVmac239-infected rhesus macaque eliciting Gag206-216-specific CTL responses. CONCLUSIONS These results present in vitro and in vivo evidence implicating the interaction between Gag residues 205 in CA NTD and 340 in CA CTD in SIV replication. Thus, this study indicates a structural constraint for functional interaction between SIV CA NTD and CTD, providing insight into immunogen design to limit viral escape options.
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Affiliation(s)
- Natsuko Inagaki
- International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
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Towards Inhibition of Vif-APOBEC3G Interaction: Which Protein to Target? Adv Virol 2010; 2010:649315. [PMID: 22347227 PMCID: PMC3275931 DOI: 10.1155/2010/649315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2010] [Revised: 07/31/2010] [Accepted: 08/14/2010] [Indexed: 11/17/2022] Open
Abstract
APOBEC proteins appeared in the cellular battle against HIV-1 as part of intrinsic cellular immunity. The antiretroviral activity of some of these proteins is overtaken by the action of HIV-1 Viral Infectivity Factor (Vif) protein. Since the discovery of APOBEC3G (A3G) as an antiviral factor, many advances have been made to understand its mechanism of action in the cell and how Vif acts in order to counteract its activity. The mainstream concept is that Vif overcomes the innate antiviral activity of A3G by direct protein binding and promoting its degradation via the cellular ubiquitin/proteasomal pathway. Vif may also inhibit A3G through mechanisms independent of proteasomal degradation. Binding of Vif to A3G is essential for its degradation since disruption of this interaction is predicted to stimulate intracellular antiviral immunity. In this paper we will discuss the different binding partners between both proteins as one of the major challenges for the development of new antiviral drugs.
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Kono K, Song H, Yokoyama M, Sato H, Shioda T, Nakayama EE. Multiple sites in the N-terminal half of simian immunodeficiency virus capsid protein contribute to evasion from rhesus monkey TRIM5α-mediated restriction. Retrovirology 2010; 7:72. [PMID: 20825647 PMCID: PMC2944288 DOI: 10.1186/1742-4690-7-72] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 09/08/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We previously reported that cynomolgus monkey (CM) TRIM5α could restrict human immunodeficiency virus type 2 (HIV-2) strains carrying a proline at the 120th position of the capsid protein (CA), but it failed to restrict those with a glutamine or an alanine. In contrast, rhesus monkey (Rh) TRIM5α could restrict all HIV-2 strains tested but not simian immunodeficiency virus isolated from macaque (SIVmac), despite its genetic similarity to HIV-2. RESULTS We attempted to identify the viral determinant of SIVmac evasion from Rh TRIM5α-mediated restriction using chimeric viruses formed between SIVmac239 and HIV-2 GH123 strains. Consistent with a previous study, chimeric viruses carrying the loop between α-helices 4 and 5 (L4/5) (from the 82nd to 99th amino acid residues) of HIV-2 CA were efficiently restricted by Rh TRIM5α. However, the corresponding loop of SIVmac239 CA alone (from the 81st to 97th amino acid residues) was not sufficient to evade Rh TRIM5α restriction in the HIV-2 background. A single glutamine-to-proline substitution at the 118th amino acid of SIVmac239 CA, corresponding to the 120th amino acid of HIV-2 GH123, also increased susceptibility to Rh TRIM5α, indicating that glutamine at the 118th of SIVmac239 CA is necessary to evade Rh TRIM5α. In addition, the N-terminal portion (from the 5th to 12th amino acid residues) and the 107th and 109th amino acid residues in α-helix 6 of SIVmac CA are necessary for complete evasion from Rh TRIM5α-mediated restriction. A three-dimensional model of hexameric GH123 CA showed that these multiple regions are located on the CA surface, suggesting their direct interaction with TRIM5α. CONCLUSION We found that multiple regions of the SIVmac CA are necessary for complete evasion from Rh TRIM5α restriction.
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Affiliation(s)
- Ken Kono
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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Onyango CO, Leligdowicz A, Yokoyama M, Sato H, Song H, Nakayama EE, Shioda T, de Silva T, Townend J, Jaye A, Whittle H, Rowland-Jones S, Cotten M. HIV-2 capsids distinguish high and low virus load patients in a West African community cohort. Vaccine 2010; 28 Suppl 2:B60-7. [PMID: 20510746 DOI: 10.1016/j.vaccine.2009.08.060] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 08/13/2009] [Accepted: 08/17/2009] [Indexed: 12/11/2022]
Abstract
HIV-2 causes AIDS similar to HIV-1, however a considerable proportion of HIV-2 infected patients show no disease and have low plasma virus load (VL). An analysis of HIV-2 capsid (p26) variation demonstrated that proline at p26 positions 119, 159 and 178 are more frequent in lower VL subjects while non-proline residues at all three sites are more frequent in subjects with high VL. In vitro replication levels of viruses bearing changes at the three sites suggested that these three residues influence virus replication by altering susceptibility to TRIM5alpha. These results provide new insights into HIV-2 pathogenesis.
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Affiliation(s)
- Clayton O Onyango
- Medical Research Council Laboratories, Fajara, Atlantic Road, PO Box 273, The Gambia.
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Ode H, Yokoyama M, Kanda T, Sato H. Identification of folding preferences of cleavage junctions of HIV-1 precursor proteins for regulation of cleavability. J Mol Model 2010; 17:391-9. [PMID: 20480379 DOI: 10.1007/s00894-010-0739-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 04/30/2010] [Indexed: 11/30/2022]
Abstract
Human immunodeficiency virus type 1 protease (HIV-1 PR) cleaves two viral precursor proteins, Gag and Gag-Pol, at multiple sites. Although the processing proceeds in the rank order to assure effective viral replication, the molecular mechanisms by which the order is regulated are not fully understood. In this study, we used bioinformatics approaches to examine whether the folding preferences of the cleavage junctions influence their cleavabilities by HIV-1 PR. The folding of the eight-amino-acid peptides corresponding to the seven cleavage junctions of the HIV-1(HXB2) Gag and Gag-Pol precursors were simulated in the PR-free and PR-bound states with molecular dynamics and homology modeling methods, and the relationships between the folding parameters and the reported kinetic parameters of the HIV-1(HXB2) peptides were analyzed. We found that a folding preference for forming a dihedral angle of Cβ (P1)-Cα (P1)- Cα (P1')-Cβ (P1') in the range of 150 to 180 degrees in the PR-free state was positively correlated with the 1/K(m) (R = 0.95, P = 0.0008) and that the dihedral angle of the O (P2)-C (P2)- C (P1)- O (P1) of the main chains in the PR-bound state was negatively correlated with k(cat) (R = 0.94, P = 0.001). We further found that these two folding properties influenced the overall cleavability of the precursor protein when the sizes of the side chains at the P1 site were similar. These data suggest that the dihedral angles at the specific positions around the cleavage junctions before and after binding to PR are both critical for regulating the cleavability of precursor proteins by HIV-1 PR.
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Affiliation(s)
- Hirotaka Ode
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan.
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