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Qin Z, Bonifati S, St Gelais C, Li TW, Kim SH, Antonucci JM, Mahboubi B, Yount JS, Xiong Y, Kim B, Wu L. The dNTPase activity of SAMHD1 is important for its suppression of innate immune responses in differentiated monocytic cells. J Biol Chem 2020; 295:1575-1586. [PMID: 31914403 PMCID: PMC7008377 DOI: 10.1074/jbc.ra119.010360] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/22/2019] [Indexed: 12/18/2022] Open
Abstract
Sterile alpha motif and HD domain-containing protein 1 (SAMHD1) is a deoxynucleoside triphosphohydrolase (dNTPase) with a nuclear localization signal (NLS). SAMHD1 suppresses innate immune responses to viral infection and inflammatory stimuli by inhibiting the NF-κB and type I interferon (IFN-I) pathways. However, whether the dNTPase activity and nuclear localization of SAMHD1 are required for its suppression of innate immunity remains unknown. Here, we report that the dNTPase activity, but not nuclear localization of SAMHD1, is important for its suppression of innate immune responses in differentiated monocytic cells. We generated monocytic U937 cell lines stably expressing WT SAMHD1 or mutated variants defective in dNTPase activity (HD/RN) or nuclear localization (mNLS). WT SAMHD1 in differentiated U937 cells significantly inhibited lipopolysaccharide-induced expression of tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) mRNAs, as well as IFN-α, IFN-β, and TNF-α mRNA levels induced by Sendai virus infection. In contrast, the HD/RN mutant did not exhibit this inhibition in either U937 or THP-1 cells, indicating that the dNTPase activity of SAMHD1 is important for suppressing NF-κB activation. Of note, in lipopolysaccharide-treated or Sendai virus-infected U937 or THP-1 cells, the mNLS variant reduced TNF-α or IFN-β mRNA expression to a similar extent as did WT SAMHD1, suggesting that SAMHD1-mediated inhibition of innate immune responses is independent of SAMHD1's nuclear localization. Moreover, WT and mutant SAMHD1 similarly interacted with key proteins in NF-κB and IFN-I pathways in cells. This study further defines the role and mechanisms of SAMHD1 in suppressing innate immunity.
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Affiliation(s)
- Zhihua Qin
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210; Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Serena Bonifati
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Tai-Wei Li
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Sun-Hee Kim
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Jenna M Antonucci
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210
| | - Bijan Mahboubi
- Center for Drug Discovery, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Jacob S Yount
- Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio 43210
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Baek Kim
- Center for Drug Discovery, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210; Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242; Department of Microbial Infection and Immunity, Infectious Diseases Institute, The Ohio State University, Columbus, Ohio 43210.
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Chen S, Bonifati S, Qin Z, St Gelais C, Wu L. SAMHD1 Suppression of Antiviral Immune Responses. Trends Microbiol 2018; 27:254-267. [PMID: 30336972 DOI: 10.1016/j.tim.2018.09.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/17/2018] [Accepted: 09/26/2018] [Indexed: 12/18/2022]
Abstract
SAMHD1 is a host triphosphohydrolase that degrades intracellular deoxynucleoside triphosphates (dNTPs) to a lower level that restricts viral DNA synthesis, and thus prevents replication of diverse viruses in nondividing cells. Recent progress indicates that SAMHD1 negatively regulates antiviral innate immune responses and inflammation through interacting with various key proteins in immune signaling and DNA damage-repair pathways. SAMHD1 can also modulate antibody production in adaptive immune responses. In this review, we summarize how SAMHD1 regulates antiviral immune responses through distinct mechanisms, and discuss the implications of these new functions of SAMHD1. Furthermore, we propose important new questions and future directions that can advance functional and mechanistic studies of SAMHD1-mediated immune regulation during viral infections.
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Affiliation(s)
- Shuliang Chen
- School of Basic Medical Sciences, Wuhan University, Wuhan, 430071, PR China; Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Serena Bonifati
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Zhihua Qin
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA; Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA.
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3
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Lu W, Tirumuru N, St Gelais C, Koneru PC, Liu C, Kvaratskhelia M, He C, Wu L. N6-Methyladenosine-binding proteins suppress HIV-1 infectivity and viral production. J Biol Chem 2018; 293:12992-13005. [PMID: 29976753 PMCID: PMC6109920 DOI: 10.1074/jbc.ra118.004215] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 06/27/2018] [Indexed: 11/06/2022] Open
Abstract
The internal N6-methyladenosine (m6A) modification of cellular mRNA regulates post-transcriptional gene expression. The YTH domain family proteins (YTHDF1-3 or Y1-3) bind to m6A-modified cellular mRNAs and modulate their metabolism and processing, thereby affecting cellular protein translation. We previously reported that HIV-1 RNA contains the m6A modification and that Y1-3 proteins inhibit HIV-1 infection by decreasing HIV-1 reverse transcription activity. Here, we investigated the mechanisms of Y1-3-mediated inhibition of HIV-1 infection in target cells and the effect of Y1-3 on viral production levels in virus-producing cells. We found that Y1-3 protein overexpression in HIV-1 target cells decreases viral genomic RNA (gRNA) levels and inhibits both early and late reverse transcription. Purified recombinant Y1-3 proteins preferentially bound to the m6A-modified 5' leader sequence of gRNA compared with its unmodified RNA counterpart, consistent with the strong binding of Y1-3 proteins to HIV-1 gRNA in infected cells. HIV-1 mutants with two altered m6A modification sites in the 5' leader sequence of gRNA exhibited significantly lower infectivity than WT, replication-competent HIV-1, confirming that these sites alter viral infection. HIV-1 produced from cells in which endogenous Y1, Y3, or Y1-3 proteins were knocked down singly or together had increased viral infectivity compared with HIV-1 produced in control cells. Interestingly, we found that Y1-3 proteins and HIV-1 Gag protein formed a complex with RNA in HIV-1-producing cells. Overall, these results indicate that Y1-3 proteins inhibit HIV-1 infection and provide new insights into the mechanisms by which the m6A modification of HIV-1 RNA affects viral replication.
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Affiliation(s)
- Wuxun Lu
- From the Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210
| | - Nagaraja Tirumuru
- From the Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210
| | - Corine St Gelais
- From the Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210
| | - Pratibha C Koneru
- the Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado 80045, and
| | - Chang Liu
- the Departments of Chemistry and of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, and
- Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois 60637
| | - Mamuka Kvaratskhelia
- the Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado 80045, and
| | - Chuan He
- the Departments of Chemistry and of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, and
- Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois 60637
| | - Li Wu
- From the Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210,
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4
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Antonucci JM, Kim SH, St Gelais C, Bonifati S, Li TW, Buzovetsky O, Knecht KM, Duchon AA, Xiong Y, Musier-Forsyth K, Wu L. SAMHD1 Impairs HIV-1 Gene Expression and Negatively Modulates Reactivation of Viral Latency in CD4 + T Cells. J Virol 2018; 92:e00292-18. [PMID: 29793958 PMCID: PMC6052313 DOI: 10.1128/jvi.00292-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/15/2018] [Indexed: 11/20/2022] Open
Abstract
Sterile alpha motif and HD domain-containing protein 1 (SAMHD1) restricts human immunodeficiency virus type 1 (HIV-1) replication in nondividing cells by degrading intracellular deoxynucleoside triphosphates (dNTPs). SAMHD1 is highly expressed in resting CD4+ T cells, which are important for the HIV-1 reservoir and viral latency; however, whether SAMHD1 affects HIV-1 latency is unknown. Recombinant SAMHD1 binds HIV-1 DNA or RNA fragments in vitro, but the function of this binding remains unclear. Here we investigate the effect of SAMHD1 on HIV-1 gene expression and reactivation of viral latency. We found that endogenous SAMHD1 impaired HIV-1 long terminal repeat (LTR) activity in monocytic THP-1 cells and HIV-1 reactivation in latently infected primary CD4+ T cells. Overexpression of wild-type (WT) SAMHD1 suppressed HIV-1 LTR-driven gene expression at a transcriptional level. Tat coexpression abrogated SAMHD1-mediated suppression of HIV-1 LTR-driven luciferase expression. SAMHD1 overexpression also suppressed the LTR activity of human T-cell leukemia virus type 1 (HTLV-1), but not that of murine leukemia virus (MLV), suggesting specific suppression of retroviral LTR-driven gene expression. WT SAMHD1 bound to proviral DNA and impaired reactivation of HIV-1 gene expression in latently infected J-Lat cells. In contrast, a nonphosphorylated mutant (T592A) and a dNTP triphosphohydrolase (dNTPase) inactive mutant (H206D R207N [HD/RN]) of SAMHD1 failed to efficiently suppress HIV-1 LTR-driven gene expression and reactivation of latent virus. Purified recombinant WT SAMHD1, but not the T592A and HD/RN mutants, bound to fragments of the HIV-1 LTR in vitro These findings suggest that SAMHD1-mediated suppression of HIV-1 LTR-driven gene expression potentially regulates viral latency in CD4+ T cells.IMPORTANCE A critical barrier to developing a cure for HIV-1 infection is the long-lived viral reservoir that exists in resting CD4+ T cells, the main targets of HIV-1. The viral reservoir is maintained through a variety of mechanisms, including regulation of the HIV-1 LTR promoter. The host protein SAMHD1 restricts HIV-1 replication in nondividing cells, but its role in HIV-1 latency remains unknown. Here we report a new function of SAMHD1 in regulating HIV-1 latency. We found that SAMHD1 suppressed HIV-1 LTR promoter-driven gene expression and reactivation of viral latency in cell lines and primary CD4+ T cells. Furthermore, SAMHD1 bound to the HIV-1 LTR in vitro and in a latently infected CD4+ T-cell line, suggesting that the binding may negatively modulate reactivation of HIV-1 latency. Our findings indicate a novel role for SAMHD1 in regulating HIV-1 latency, which enhances our understanding of the mechanisms regulating proviral gene expression in CD4+ T cells.
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Affiliation(s)
- Jenna M Antonucci
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Sun Hee Kim
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Corine St Gelais
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Serena Bonifati
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Tai-Wei Li
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
| | - Olga Buzovetsky
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Kirsten M Knecht
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Alice A Duchon
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Karin Musier-Forsyth
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Li Wu
- Center for Retrovirus Research, The Ohio State University, Columbus, Ohio, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, USA
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA
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5
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Antonucci JM, St Gelais C, de Silva S, Yount JS, Tang C, Ji X, Shepard C, Xiong Y, Kim B, Wu L. SAMHD1-mediated HIV-1 restriction in cells does not involve ribonuclease activity. Nat Med 2018; 22:1072-1074. [PMID: 27711056 DOI: 10.1038/nm.4163] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Jenna M Antonucci
- Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio, USA.,Department of Microbiology, Ohio State University, Columbus, Ohio, USA
| | - Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio, USA
| | - Suresh de Silva
- Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio, USA
| | - Jacob S Yount
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA
| | - Chenxiang Tang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, USA
| | - Xiaoyun Ji
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, USA
| | - Caitlin Shepard
- Department of Pediatrics, Center for Drug Discovery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, USA
| | - Baek Kim
- Department of Pediatrics, Center for Drug Discovery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio, USA.,Department of Microbiology, Ohio State University, Columbus, Ohio, USA.,Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA
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6
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Antonucci JM, St Gelais C, Wu L. The Dynamic Interplay between HIV-1, SAMHD1, and the Innate Antiviral Response. Front Immunol 2017; 8:1541. [PMID: 29176984 PMCID: PMC5686096 DOI: 10.3389/fimmu.2017.01541] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 10/30/2017] [Indexed: 01/03/2023] Open
Abstract
The innate immune response constitutes the first cellular line of defense against initial HIV-1 infection. Immune cells sense invading virus and trigger signaling cascades that induce antiviral defenses to control or eliminate infection. Professional antigen-presenting cells located in mucosal tissues, including dendritic cells and macrophages, are critical for recognizing HIV-1 at the site of initial exposure. These cells are less permissive to HIV-1 infection compared to activated CD4+ T-cells, which is mainly due to host restriction factors that serve an immediate role in controlling the establishment or spread of viral infection. However, HIV-1 can exploit innate immune cells and their cellular factors to avoid detection and clearance by the host immune system. Sterile alpha motif and HD-domain containing protein 1 (SAMHD1) is the mammalian deoxynucleoside triphosphate triphosphohydrolase responsible for regulating intracellular dNTP pools and restricting the replication of HIV-1 in non-dividing myeloid cells and quiescent CD4+ T-cells. Here, we review and analyze the latest literature on the antiviral function of SAMHD1, including the mechanism of HIV-1 restriction and the ability of SAMHD1 to regulate the innate immune response to viral infection. We also provide an overview of the dynamic interplay between HIV-1, SAMHD1, and the cell-intrinsic antiviral response to elucidate how SAMHD1 modulates HIV-1 infection in non-dividing immune cells. A more complete understanding of SAMHD1’s role in the innate immune response to HIV-1 infection may help develop stratagems to enhance its antiviral effects and to more efficiently block HIV-1 replication and avoid the pathogenic result of viral infection.
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Affiliation(s)
- Jenna M Antonucci
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, United States
| | - Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, United States
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, United States
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Kenney AD, Dowdle JA, Bozzacco L, McMichael TM, St Gelais C, Panfil AR, Sun Y, Schlesinger LS, Anderson MZ, Green PL, López CB, Rosenberg BR, Wu L, Yount JS. Human Genetic Determinants of Viral Diseases. Annu Rev Genet 2017; 51:241-263. [PMID: 28853921 DOI: 10.1146/annurev-genet-120116-023425] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Much progress has been made in the identification of specific human gene variants that contribute to enhanced susceptibility or resistance to viral diseases. Herein we review multiple discoveries made with genome-wide or candidate gene approaches that have revealed significant insights into virus-host interactions. Genetic factors that have been identified include genes encoding virus receptors, receptor-modifying enzymes, and a wide variety of innate and adaptive immunity-related proteins. We discuss a range of pathogenic viruses, including influenza virus, respiratory syncytial virus, human immunodeficiency virus, human T cell leukemia virus, human papilloma virus, hepatitis B and C viruses, herpes simplex virus, norovirus, rotavirus, parvovirus, and Epstein-Barr virus. Understanding the genetic underpinnings that affect infectious disease outcomes should allow tailored treatment and prevention approaches in the future.
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Affiliation(s)
- Adam D Kenney
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - James A Dowdle
- Department of Cancer Biology and Genetics, The Ohio State University, Columbus, Ohio 43210, USA;
| | - Leonia Bozzacco
- Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY 10065, USA.,Current affiliation: Target Information Group, Regeneron Pharmaceuticals, Inc., Tarrytown, New York 10591, USA;
| | - Temet M McMichael
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Corine St Gelais
- Center of Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Amanda R Panfil
- Center of Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Yan Sun
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; ,
| | - Larry S Schlesinger
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , , .,Texas Biomedical Research Institute, San Antonio, Texas 78227, USA;
| | - Matthew Z Anderson
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Patrick L Green
- Center of Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Carolina B López
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA; ,
| | - Brad R Rosenberg
- Program in Immunogenomics, John C. Whitehead Presidential Fellows Program, The Rockefeller University, New York, NY 10065, USA.,Current affiliation: Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Li Wu
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , , .,Center of Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
| | - Jacob S Yount
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, USA; , , ,
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St Gelais C, Kim SH, Ding L, Yount JS, Ivanov D, Spearman P, Wu L. A Putative Cyclin-binding Motif in Human SAMHD1 Contributes to Protein Phosphorylation, Localization, and Stability. J Biol Chem 2016; 291:26332-26342. [PMID: 27815502 DOI: 10.1074/jbc.m116.753947] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 10/26/2016] [Indexed: 01/01/2023] Open
Abstract
SAMHD1 (sterile α motif and HD domain-containing protein 1) is a mammalian protein that regulates intracellular dNTP levels through its hydrolysis of dNTPs. SAMHD1 functions as an important retroviral restriction factor through a mechanism relying on its dNTPase activity. We and others have reported that human SAMHD1 interacts with the cell cycle regulatory proteins cyclin A, CDK1, and CDK2, which mediates phosphorylation of SAMHD1 at threonine 592, a post-translational modification that has been implicated in abrogating SAMHD1 restriction function and ability to form stable tetramers. Utilizing co-immunoprecipitation and co-localization approaches, we show that endogenous SAMHD1 is able to interact with the cyclin A-CDK1-CDK2 complexin monocytic THP-1 cells and primary monocyte-derived macrophages. Sequence analysis of SAMHD1 identifies a putative cyclin-binding motif found in many cyclin-CDK complex substrates. Using a mutagenesis-based approach, we demonstrate that the conserved residues in the putative cyclin-binding motif are important for protein expression, protein half-life, and optimal phosphorylation of SAMHD1 at Thr592 Furthermore, we observed that SAMHD1 mutants of the cyclin-binding motif mislocalized to a nuclear compartment and had reduced ability to interact with cyclin A-CDK complexes and to form the tetramer. These findings help define the mechanisms by which SAMHD1 is phosphorylated and suggest the contribution of cyclin binding to SAMHD1 expression and stability in dividing cells.
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Affiliation(s)
- Corine St Gelais
- From the Center of Retrovirus Research, Department of Veterinary Biosciences and
| | - Sun Hee Kim
- From the Center of Retrovirus Research, Department of Veterinary Biosciences and
| | - Lingmei Ding
- the Department of Pediatrics, Emory University, Atlanta, Georgia 30322
| | - Jacob S Yount
- the Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio 43210
| | - Dmitri Ivanov
- the Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229
| | - Paul Spearman
- the Department of Pediatrics, Emory University, Atlanta, Georgia 30322.,Children's Healthcare of Atlanta, Atlanta, Georgia 30322, and
| | - Li Wu
- From the Center of Retrovirus Research, Department of Veterinary Biosciences and .,the Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio 43210
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9
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Bonifati S, Daly MB, St Gelais C, Kim SH, Hollenbaugh JA, Shepard C, Kennedy EM, Kim DH, Schinazi RF, Kim B, Wu L. SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells. Virology 2016; 495:92-100. [PMID: 27183329 DOI: 10.1016/j.virol.2016.05.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 05/03/2016] [Indexed: 01/09/2023]
Abstract
SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G1/G0 phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection.
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Affiliation(s)
- Serena Bonifati
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA
| | - Michele B Daly
- Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA
| | - Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA
| | - Sun Hee Kim
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA
| | - Joseph A Hollenbaugh
- Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA
| | - Caitlin Shepard
- Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA
| | - Edward M Kennedy
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | - Dong-Hyun Kim
- Department of Pharmacy, School of Pharmacy, Kyung-Hee University, Seoul, South Korea
| | - Raymond F Schinazi
- Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA
| | - Baek Kim
- Center for Drug Discovery, Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA, USA; Department of Pharmacy, School of Pharmacy, Kyung-Hee University, Seoul, South Korea.
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA.
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Wang F, St Gelais C, de Silva S, Zhang H, Geng Y, Shepard C, Kim B, Yount JS, Wu L. Phosphorylation of mouse SAMHD1 regulates its restriction of human immunodeficiency virus type 1 infection, but not murine leukemia virus infection. Virology 2015; 487:273-84. [PMID: 26580513 DOI: 10.1016/j.virol.2015.10.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/25/2015] [Accepted: 10/27/2015] [Indexed: 11/29/2022]
Abstract
Human SAMHD1 (hSAMHD1) restricts HIV-1 infection in non-dividing cells by depleting intracellular dNTPs to limit viral reverse transcription. Phosphorylation of hSAMHD1 at threonine (T) 592 by cyclin-dependent kinase (CDK) 1 and CDK2 negatively regulates HIV-1 restriction. Mouse SAMHD1 (mSAMHD1) restricts HIV-1 infection in non-dividing cells, but whether its phosphorylation regulates retroviral restriction is unknown. Here we identified six phospho-sites of mSAMHD1, including T634 that is homologous to T592 of hSAMHD1 and phosphorylated by CDK1 and CDK2. We found that wild-type (WT) mSAMHD1 and a phospho-ablative mutant, but not a phospho-mimetic mutant, restricted HIV-1 infection in differentiated U937 cells. Murine leukemia virus (MLV) infection of dividing NIH3T3 cells was modestly restricted by mSAMHD1 WT and phospho-mutants, but not by a dNTPase-defective mutant. Our results suggest that phosphorylation of mSAMHD1 at T634 by CDK1/2 negatively regulates its HIV-1 restriction in differentiated cells, but does not affect its MLV restriction in dividing cells.
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Affiliation(s)
- Feifei Wang
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
| | - Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
| | - Suresh de Silva
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
| | - Hong Zhang
- ProSci, Inc., 12170 Flint Place, Poway, CA, USA
| | - Yu Geng
- ProSci, Inc., 12170 Flint Place, Poway, CA, USA
| | - Caitlin Shepard
- Department of Pediatrics, Center for Drug Discovery, Emory University School of Medicine, 1760 Haygood Drive, Atlanta, GA, USA
| | - Baek Kim
- Department of Pediatrics, Center for Drug Discovery, Emory University School of Medicine, 1760 Haygood Drive, Atlanta, GA, USA
| | - Jacob S Yount
- Center for Microbial Interface Biology, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA; Department of Microbial Infection and Immunity, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
| | - Li Wu
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA; Center for Microbial Interface Biology, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA; Department of Microbial Infection and Immunity, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA; Comprehensive Cancer Center, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA.
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St Gelais C, de Silva S, Amie SM, Coleman CM, Hoy H, Hollenbaugh JA, Kim B, Wu L. SAMHD1 restricts HIV-1 infection in dendritic cells (DCs) by dNTP depletion, but its expression in DCs and primary CD4+ T-lymphocytes cannot be upregulated by interferons. Retrovirology 2012; 9:105. [PMID: 23231760 PMCID: PMC3527137 DOI: 10.1186/1742-4690-9-105] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Accepted: 11/29/2012] [Indexed: 01/10/2023] Open
Abstract
Background SAMHD1 is an HIV-1 restriction factor in non-dividing monocytes, dendritic cells (DCs), macrophages, and resting CD4+ T-cells. Acting as a deoxynucleoside triphosphate (dNTP) triphosphohydrolase, SAMHD1 hydrolyzes dNTPs and restricts HIV-1 infection in macrophages and resting CD4+ T-cells by decreasing the intracellular dNTP pool. However, the intracellular dNTP pool in DCs and its regulation by SAMHD1 remain unclear. SAMHD1 has been reported as a type I interferon (IFN)-inducible protein, but whether type I IFNs upregulate SAMHD1 expression in primary DCs and CD4+ T-lymphocytes is unknown. Results Here, we report that SAMHD1 significantly blocked single-cycle and replication-competent HIV-1 infection of DCs by decreasing the intracellular dNTP pool and thereby limiting the accumulation of HIV-1 late reverse transcription products. Type I IFN treatment did not upregulate endogenous SAMHD1 expression in primary DCs or CD4+ T-lymphocytes, but did in HEK 293T and HeLa cell lines. When SAMHD1 was over-expressed in these two cell lines to achieve higher levels than that in DCs, no HIV-1 restriction was observed despite partially reducing the intracellular dNTP pool. Conclusions Our results suggest that SAMHD1-mediated reduction of the intracellular dNTP pool in DCs is a common mechanism of HIV-1 restriction in myeloid cells. Endogenous expression of SAMHD1 in primary DCs or CD4+ T-lymphocytes is not upregulated by type I IFNs.
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Affiliation(s)
- Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Biosciences, The Ohio State University, 1900 Coffey Road, Columbus, Ohio 43210, USA
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Abstract
Human myeloid-lineage cells are refractory to HIV-1 infection. The Vpx proteins from HIV-2 and sooty mangabey SIV render these cells permissive to HIV-1 infection through proteasomal degradation of a putative restriction factor. Two recent studies discovered the cellular protein SAMHD1 to be this restriction factor, demonstrating that Vpx induces proteasomal degradation of SAMHD1 and enhances HIV-1 infection in myeloid-lineage cells. SAMHD1 functions as a myeloid-cell-specific HIV-1 restriction factor by inhibiting viral DNA synthesis. Here we discuss the implications of these findings in delineating the mechanisms of HIV-1 restriction in myeloid-lineage cells and the potential role of Vpx in lentiviral pathogenesis.
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Affiliation(s)
- Corine St Gelais
- Center for Retrovirus Research, Department of Veterinary Bioscience, The Ohio State University, 1900 Coffey Road, Columbus, OH 43210, USA
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