1
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Thapa G, Bhattacharya A, Bhattacharya S. Molecular dynamics investigation of DNA fragments bound to the anti-HIV protein SAMHD1 reveals alterations in allosteric communications. J Mol Graph Model 2024; 129:108748. [PMID: 38452417 DOI: 10.1016/j.jmgm.2024.108748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 03/09/2024]
Abstract
The sterile alpha motif and histidine-aspartate domain-containing protein 1 (or SAMHD1), a human dNTP-triphosphohydrolase, contributes to HIV-1 restriction in select terminally differentiated cells of the immune system. While the prevailing hypothesis is that the catalytically active form of the protein is an allosterically triggered tetramer, whose HIV-1 restriction properties are attributed to its dNTP - triphosphohydrolase activity, it is also known to bind to ssRNA and ssDNA oligomers. A complete picture of the structure-function relationship of the enzyme is still elusive and the function corresponding to its nucleic acid binding ability is debated. In this in silico study, we investigate the stability, preference and allosteric effects of DNA oligomers bound to SAMHD1. In particular, we compare the binding of DNA and RNA oligomers of the same sequence and also consider the binding of DNA fragments with phosphorothioate bonds in the backbone. The results are compared with the canonical form with the monomers connected by GTP/dATP crossbridges. The simulations indicate that SAMHD1 dimers preferably bind to DNA and RNA oligomers compared to GTP/dATP. However, allosteric communication channels are altered in the nucleic acid acid bound complexes compared to the canonical form. All results are consistent with the hypothesis that the DNA bound form of the protein correspond to an unproductive off-pathway state where the protein is sequestered and not available for dNTP hydrolysis.
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Affiliation(s)
- Gauri Thapa
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
| | | | - Swati Bhattacharya
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.
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2
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Orris B, Sung MW, Bhat S, Xu Y, Huynh KW, Han S, Johnson DC, Bosbach B, Shields DJ, Stivers JT. Guanine-containing ssDNA and RNA induce dimeric and tetrameric structural forms of SAMHD1. Nucleic Acids Res 2023; 51:12443-12458. [PMID: 37930833 PMCID: PMC10711556 DOI: 10.1093/nar/gkad971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/19/2023] [Accepted: 10/14/2023] [Indexed: 11/08/2023] Open
Abstract
The dNTPase activity of tetrameric SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1) plays a critical role in cellular dNTP regulation. SAMHD1 also associates with stalled DNA replication forks, DNA repair foci, ssRNA and telomeres. The above functions require nucleic acid binding by SAMHD1, which may be modulated by its oligomeric state. Here we establish in cryo-EM and biochemical studies that the guanine-specific A1 activator site of each SAMHD1 monomer is used to target the enzyme to guanine nucleotides within single-stranded (ss) DNA and RNA. Remarkably, nucleic acid strands containing a single guanine base induce dimeric SAMHD1, while two or more guanines with ∼20 nucleotide spacing induce a tetrameric form. A cryo-EM structure of ssRNA-bound tetrameric SAMHD1 shows how ssRNA strands bridge two SAMHD1 dimers and stabilize the structure. This ssRNA-bound tetramer is inactive with respect to dNTPase and RNase activity.
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Affiliation(s)
- Benjamin Orris
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205, USA
| | | | - Shridhar Bhat
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205, USA
| | - Yingrong Xu
- Medicine Design, Pfizer, Groton, CT 06340, USA
| | | | - Seungil Han
- Medicine Design, Pfizer, Groton, CT 06340, USA
| | - Darren C Johnson
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016, USA
| | - Benedikt Bosbach
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016, USA
| | - David J Shields
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016, USA
| | - James T Stivers
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205, USA
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3
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Schüssler M, Schott K, Fuchs NV, Oo A, Zahadi M, Rauch P, Kim B, König R. Gene editing of SAMHD1 in macrophage-like cells reveals complex relationships between SAMHD1 phospho-regulation, HIV-1 restriction, and cellular dNTP levels. mBio 2023; 14:e0225223. [PMID: 37800914 PMCID: PMC10653793 DOI: 10.1128/mbio.02252-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 08/25/2023] [Indexed: 10/07/2023] Open
Abstract
IMPORTANCE We introduce BLaER1 cells as an alternative myeloid cell model in combination with CRISPR/Cas9-mediated gene editing to study the influence of sterile α motif and HD domain-containing protein 1 (SAMHD1) T592 phosphorylation on anti-viral restriction and the control of cellular dNTP levels in an endogenous, physiologically relevant context. A proper understanding of the mechanism of the anti-viral function of SAMHD1 will provide attractive strategies aiming at selectively manipulating SAMHD1 without affecting other cellular functions. Even more, our toolkit may inspire further genetic analysis and investigation of restriction factors inhibiting retroviruses and their cellular function and regulation, leading to a deeper understanding of intrinsic anti-viral immunity.
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Affiliation(s)
- Moritz Schüssler
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Kerstin Schott
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | | | - Adrian Oo
- Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Morssal Zahadi
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Paula Rauch
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Baek Kim
- Department of Pediatrics, Emory University, Atlanta, Georgia, USA
- Center for Drug Discovery, Children’s Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
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4
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Egleston M, Dong L, Howlader AH, Bhat S, Orris B, Bianchet MA, Greenberg MM, Stivers JT. Deoxyguanosine-Linked Bifunctional Inhibitor of SAMHD1 dNTPase Activity and Nucleic Acid Binding. ACS Chem Biol 2023; 18:2200-2210. [PMID: 37233733 PMCID: PMC10596003 DOI: 10.1021/acschembio.3c00118] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 05/10/2023] [Indexed: 05/27/2023]
Abstract
Sterile alpha motif histidine-aspartate domain protein 1 (SAMHD1) is a deoxynucleotide triphosphohydrolase that exists in monomeric, dimeric, and tetrameric forms. It is activated by GTP binding to an A1 allosteric site on each monomer subunit, which induces dimerization, a prerequisite for dNTP-induced tetramerization. SAMHD1 is a validated drug target stemming from its inactivation of many anticancer nucleoside drugs leading to drug resistance. The enzyme also possesses a single-strand nucleic acid binding function that promotes RNA and DNA homeostasis by several mechanisms. To discover small molecule inhibitors of SAMHD1, we screened a custom ∼69 000-compound library for dNTPase inhibitors. Surprisingly, this effort yielded no viable hits and indicated that exceptional barriers for discovery of small molecule inhibitors existed. We then took a rational fragment-based inhibitor design approach using a deoxyguanosine (dG) A1 site targeting fragment. A targeted chemical library was synthesized by coupling a 5'-phosphoryl propylamine dG fragment (dGpC3NH2) to 376 carboxylic acids (RCOOH). Direct screening of the products (dGpC3NHCO-R) yielded nine initial hits, one of which (R = 3-(3'-bromo-[1,1'-biphenyl]), 5a) was investigated extensively. Amide 5a is a competitive inhibitor against GTP binding to the A1 site and induces inactive dimers that are deficient in tetramerization. Surprisingly, 5a also prevented ssDNA and ssRNA binding, demonstrating that the dNTPase and nucleic acid binding functions of SAMHD1 can be disrupted by a single small molecule. A structure of the SAMHD1-5a complex indicates that the biphenyl fragment impedes a conformational change in the C-terminal lobe that is required for tetramerization.
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Affiliation(s)
- Matthew Egleston
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Linghao Dong
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - A. Hasan Howlader
- Department
of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Shridhar Bhat
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Benjamin Orris
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Mario A. Bianchet
- Department
of Neurology and Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Marc M. Greenberg
- Department
of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - James T. Stivers
- Department
of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, Maryland 21205, United States
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5
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Schüssler M, Schott K, Fuchs NV, Oo A, Zahadi M, Rauch P, Kim B, König R. Gene editing of SAMHD1 in macrophage-like cells reveals complex relationships between SAMHD1 phospho-regulation, HIV-1 restriction and cellular dNTP levels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.24.554731. [PMID: 37662193 PMCID: PMC10473771 DOI: 10.1101/2023.08.24.554731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Sterile α motif (SAM) and HD domain-containing protein 1 (SAMHD1) is a dNTP triphosphate triphosphohydrolase (dNTPase) and a potent restriction factor for immunodeficiency virus 1 (HIV-1), active in myeloid and resting CD4+ T cells. The anti-viral activity of SAMHD1 is regulated by dephosphorylation of the residue T592. However, the impact of T592 phosphorylation on dNTPase activity is still under debate. Whether additional cellular functions of SAMHD1 impact anti-viral restriction is not completely understood. We report BLaER1 cells as a novel human macrophage HIV-1 infection model combined with CRISPR/Cas9 knock-in (KI) introducing specific mutations into the SAMHD1 locus to study mutations in a physiological context. Transdifferentiated BLaER1 cells harbor active dephosphorylated SAMHD1 that blocks HIV-1 reporter virus infection. As expected, homozygous T592E mutation, but not T592A, relieved a block to HIV-1 reverse transcription. Co-delivery of VLP-Vpx to SAMHD1 T592E KI mutant cells did not further enhance HIV-1 infection indicating the absence of an additional SAMHD1-mediated antiviral activity independent of T592 de-phosphorylation. T592E KI cells retained dNTP levels similar to WT cells indicating uncoupling of anti-viral and dNTPase activity of SAMHD1. The integrity of the catalytic site in SAMHD1 was critical for anti-viral activity, yet poor correlation of HIV-1 restriction and global cellular dNTP levels was observed in cells harboring catalytic core mutations. Together, we emphasize the complexity of the relationship between HIV-1 restriction, SAMHD1 enzymatic function and T592 phospho-regulation and provide novel tools for investigation in an endogenous and physiological context.
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Affiliation(s)
- Moritz Schüssler
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Kerstin Schott
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | | | - Adrian Oo
- Department of Pediatrics, Emory University, Atlanta, USA
| | - Morssal Zahadi
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Paula Rauch
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Baek Kim
- Department of Pediatrics, Emory University, Atlanta, USA
- Center for Drug Discovery, Children’s Healthcare of Atlanta, Atlanta, USA
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
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6
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Orris B, Sung MW, Bhat S, Xu Y, Huynh KW, Han S, Johnson DC, Bosbach B, Shields DJ, Stivers JT. Guanine-containing ssDNA and RNA induce dimeric and tetrameric SAMHD1 in cryo-EM and binding studies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.15.544806. [PMID: 37398126 PMCID: PMC10312740 DOI: 10.1101/2023.06.15.544806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The dNTPase activity of tetrameric SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1) plays a critical role in cellular dNTP regulation. SAMHD1 also associates with stalled DNA replication forks, DNA repair foci, ssRNA, and telomeres. The above functions require nucleic acid binding by SAMHD1, which may be modulated by its oligomeric state. Here we establish that the guanine-specific A1 activator site of each SAMHD1 monomer is used to target the enzyme to guanine nucleotides within single-stranded (ss) DNA and RNA. Remarkably, nucleic acid strands containing a single guanine base induce dimeric SAMHD1, while two or more guanines with ~20 nucleotide spacing induce a tetrameric form. A cryo-EM structure of ssRNA-bound tetrameric SAMHD1 shows how ssRNA strands bridge two SAMHD1 dimers and stabilize the structure. This ssRNA-bound tetramer is inactive with respect to dNTPase and RNase activity.
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Affiliation(s)
- Benjamin Orris
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205
| | | | - Shridhar Bhat
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205
| | | | | | | | - Darren C. Johnson
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016
| | - Benedikt Bosbach
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016
| | - David J. Shields
- Centers for Therapeutic Innovation (CTI), Pfizer, New York, NY 10016
| | - James T. Stivers
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205
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7
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Tsai MHC, Caswell SJ, Morris ER, Mann MC, Pennell S, Kelly G, Groom HCT, Taylor IA, Bishop KN. Attenuation of reverse transcriptase facilitates SAMHD1 restriction of HIV-1 in cycling cells. Retrovirology 2023; 20:5. [PMID: 37127613 PMCID: PMC10150492 DOI: 10.1186/s12977-023-00620-z] [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: 02/24/2023] [Accepted: 04/06/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND SAMHD1 is a deoxynucleotide triphosphohydrolase that restricts replication of HIV-1 in differentiated leucocytes. HIV-1 is not restricted in cycling cells and it has been proposed that this is due to phosphorylation of SAMHD1 at T592 in these cells inactivating the enzymatic activity. To distinguish between theories for how SAMHD1 restricts HIV-1 in differentiated but not cycling cells, we analysed the effects of substitutions at T592 on restriction and dNTP levels in both cycling and differentiated cells as well as tetramer stability and enzymatic activity in vitro. RESULTS We first showed that HIV-1 restriction was not due to SAMHD1 nuclease activity. We then characterised a panel of SAMHD1 T592 mutants and divided them into three classes. We found that a subset of mutants lost their ability to restrict HIV-1 in differentiated cells which generally corresponded with a decrease in triphosphohydrolase activity and/or tetramer stability in vitro. Interestingly, no T592 mutants were able to restrict WT HIV-1 in cycling cells, despite not being regulated by phosphorylation and retaining their ability to hydrolyse dNTPs. Lowering dNTP levels by addition of hydroxyurea did not give rise to restriction. Compellingly however, HIV-1 RT mutants with reduced affinity for dNTPs were significantly restricted by wild-type and T592 mutant SAMHD1 in both cycling U937 cells and Jurkat T-cells. Restriction correlated with reverse transcription levels. CONCLUSIONS Altogether, we found that the amino acid at residue 592 has a strong effect on tetramer formation and, although this is not a simple "on/off" switch, this does correlate with the ability of SAMHD1 to restrict HIV-1 replication in differentiated cells. However, preventing phosphorylation of SAMHD1 and/or lowering dNTP levels by adding hydroxyurea was not enough to restore restriction in cycling cells. Nonetheless, lowering the affinity of HIV-1 RT for dNTPs, showed that restriction is mediated by dNTP levels and we were able to observe for the first time that SAMHD1 is active and capable of inhibiting HIV-1 replication in cycling cells, if the affinity of RT for dNTPs is reduced. This suggests that the very high affinity of HIV-1 RT for dNTPs prevents HIV-1 restriction by SAMHD1 in cycling cells.
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Affiliation(s)
- Ming-Han C Tsai
- Retroviral Replication Laboratory, The Francis Crick Institute, London, UK
- LabGenius, London, UK
| | - Sarah J Caswell
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, UK
- AstraZeneca, Granta Park, Cambridge, UK
| | - Elizabeth R Morris
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, UK
- Department of Biosciences, University of Durham, Durham, UK
| | - Melanie C Mann
- Retroviral Replication Laboratory, The Francis Crick Institute, London, UK
- Sartorius, Ulm, Germany
| | - Simon Pennell
- Structural Biology of DNA-Damage Signalling Laboratory, The Francis Crick Institute, London, UK
- MRC London Institute of Medical Sciences, London, UK
| | - Geoff Kelly
- The Medical Research Council Biomedical NMR Centre, The Francis Crick Institute, London, UK
| | - Harriet C T Groom
- Retroviral Replication Laboratory, The Francis Crick Institute, London, UK
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - Ian A Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, UK
| | - Kate N Bishop
- Retroviral Replication Laboratory, The Francis Crick Institute, London, UK.
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8
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Kapoor-Vazirani P, Rath SK, Liu X, Shu Z, Bowen NE, Chen Y, Haji-Seyed-Javadi R, Daddacha W, Minten EV, Danelia D, Farchi D, Duong DM, Seyfried NT, Deng X, Ortlund EA, Kim B, Yu DS. SAMHD1 deacetylation by SIRT1 promotes DNA end resection by facilitating DNA binding at double-strand breaks. Nat Commun 2022; 13:6707. [PMID: 36344525 PMCID: PMC9640623 DOI: 10.1038/s41467-022-34578-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 10/29/2022] [Indexed: 11/09/2022] Open
Abstract
Sterile alpha motif and HD domain-containing protein 1 (SAMHD1) has a dNTPase-independent function in promoting DNA end resection to facilitate DNA double-strand break (DSB) repair by homologous recombination (HR); however, it is not known if upstream signaling events govern this activity. Here, we show that SAMHD1 is deacetylated by the SIRT1 sirtuin deacetylase, facilitating its binding with ssDNA at DSBs, to promote DNA end resection and HR. SIRT1 complexes with and deacetylates SAMHD1 at conserved lysine 354 (K354) specifically in response to DSBs. K354 deacetylation by SIRT1 promotes DNA end resection and HR but not SAMHD1 tetramerization or dNTPase activity. Mechanistically, K354 deacetylation by SIRT1 promotes SAMHD1 recruitment to DSBs and binding to ssDNA at DSBs, which in turn facilitates CtIP ssDNA binding, leading to promotion of genome integrity. These findings define a mechanism governing the dNTPase-independent resection function of SAMHD1 by SIRT1 deacetylation in promoting HR and genome stability.
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Affiliation(s)
- Priya Kapoor-Vazirani
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Sandip K Rath
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Xu Liu
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Zhen Shu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Nicole E Bowen
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Yitong Chen
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Ramona Haji-Seyed-Javadi
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Waaqo Daddacha
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Elizabeth V Minten
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Diana Danelia
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Daniela Farchi
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Xingming Deng
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Baek Kim
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - David S Yu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, 30322, USA.
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9
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Bowen NE, Oo A, Kim B. Mechanistic Interplay between HIV-1 Reverse Transcriptase Enzyme Kinetics and Host SAMHD1 Protein: Viral Myeloid-Cell Tropism and Genomic Mutagenesis. Viruses 2022; 14:v14081622. [PMID: 35893688 PMCID: PMC9331428 DOI: 10.3390/v14081622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/23/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) has been the primary interest among studies on antiviral discovery, viral replication kinetics, drug resistance, and viral evolution. Following infection and entry into target cells, the HIV-1 core disassembles, and the viral RT concomitantly converts the viral RNA into double-stranded proviral DNA, which is integrated into the host genome. The successful completion of the viral life cycle highly depends on the enzymatic DNA polymerase activity of RT. Furthermore, HIV-1 RT has long been known as an error-prone DNA polymerase due to its lack of proofreading exonuclease properties. Indeed, the low fidelity of HIV-1 RT has been considered as one of the key factors in the uniquely high rate of mutagenesis of HIV-1, which leads to efficient viral escape from immune and therapeutic antiviral selective pressures. Interestingly, a series of studies on the replication kinetics of HIV-1 in non-dividing myeloid cells and myeloid specific host restriction factor, SAM domain, and HD domain-containing protein, SAMHD1, suggest that the myeloid cell tropism and high rate of mutagenesis of HIV-1 are mechanistically connected. Here, we review not only HIV-1 RT as a key antiviral target, but also potential evolutionary and mechanistic crosstalk among the unique enzymatic features of HIV-1 RT, the replication kinetics of HIV-1, cell tropism, viral genetic mutation, and host SAMHD1 protein.
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Affiliation(s)
- Nicole E. Bowen
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
| | - Adrian Oo
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
| | - Baek Kim
- Department of Pediatrics, School of Medicine, Emory University, Atlanta, GA 30329, USA; (N.E.B.); (A.O.)
- Center for Drug Discovery, Children’s Healthcare of Atlanta, Atlanta, GA 30329, USA
- Correspondence:
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10
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Orris B, Huynh KW, Ammirati M, Han S, Bolaños B, Carmody J, Petroski MD, Bosbach B, Shields DJ, Stivers JT. Phosphorylation of SAMHD1 Thr592 increases C-terminal domain dynamics, tetramer dissociation and ssDNA binding kinetics. Nucleic Acids Res 2022; 50:7545-7559. [PMID: 35801923 PMCID: PMC9303311 DOI: 10.1093/nar/gkac573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/24/2022] [Accepted: 07/06/2022] [Indexed: 01/07/2023] Open
Abstract
SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1) is driven into its activated tetramer form by binding of GTP activator and dNTP activators/substrates. In addition, the inactive monomeric and dimeric forms of the enzyme bind to single-stranded (ss) nucleic acids. During DNA replication SAMHD1 can be phosphorylated by CDK1 and CDK2 at its C-terminal threonine 592 (pSAMHD1), localizing the enzyme to stalled replication forks (RFs) to promote their restart. Although phosphorylation has only a small effect on the dNTPase activity and ssDNA binding affinity of SAMHD1, perturbation of the native T592 by phosphorylation decreased the thermal stability of tetrameric SAMHD1 and accelerated tetramer dissociation in the absence and presence of ssDNA (∼15-fold). In addition, we found that ssDNA binds competitively with GTP to the A1 site. A full-length SAMHD1 cryo-EM structure revealed substantial dynamics in the C-terminal domain (which contains T592), which could be modulated by phosphorylation. We propose that T592 phosphorylation increases tetramer dynamics and allows invasion of ssDNA into the A1 site and the previously characterized DNA binding surface at the dimer-dimer interface. These features are consistent with rapid and regiospecific inactivation of pSAMHD1 dNTPase at RFs or other sites of free ssDNA in cells.
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Affiliation(s)
- Benjamin Orris
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205, USA
| | | | | | - Seungil Han
- Medicine Design, Pfizer, Groton, CT 06340, USA
| | - Ben Bolaños
- Oncology Research and Development, Pfizer, San Diego, CA 92121, USA
| | - Jason Carmody
- Oncology Research and Development, Pfizer, San Diego, CA 92121, USA
| | | | - Benedikt Bosbach
- Centers for Therapeutic Innovation (CTI), Pfizer, NY, NY 10016, USA
| | - David J Shields
- Centers for Therapeutic Innovation (CTI), Pfizer, NY, NY 10016, USA
| | - James T Stivers
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine 725 North Wolfe Street Baltimore, MD 21205, USA
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11
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Nucleotide Pool Imbalance and Antibody Gene Diversification. Vaccines (Basel) 2021; 9:vaccines9101050. [PMID: 34696158 PMCID: PMC8538681 DOI: 10.3390/vaccines9101050] [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: 07/30/2021] [Revised: 09/13/2021] [Accepted: 09/17/2021] [Indexed: 01/10/2023] Open
Abstract
The availability and adequate balance of deoxyribonucleoside triphosphate (dNTP) is an important determinant of both the fidelity and the processivity of DNA polymerases. Therefore, maintaining an optimal balance of the dNTP pool is critical for genomic stability in replicating and quiescent cells. Since DNA synthesis is required not only in genomic replication but also in DNA damage repair and recombination, the abnormalities in the dNTP pool affect a wide range of chromosomal activities. The generation of antibody diversity relies on antigen-independent V(D)J recombination, as well as antigen-dependent somatic hypermutation and class switch recombination. These processes involve diverse sets of DNA polymerases, which are affected by the dNTP pool imbalances. This review discusses the role of the optimal dNTP pool balance in the diversification of antibody encoding genes.
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12
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Schott K, Majer C, Bulashevska A, Childs L, Schmidt MHH, Rajalingam K, Munder M, König R. SAMHD1 in cancer: curse or cure? J Mol Med (Berl) 2021; 100:351-372. [PMID: 34480199 PMCID: PMC8843919 DOI: 10.1007/s00109-021-02131-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 07/15/2021] [Accepted: 08/12/2021] [Indexed: 12/12/2022]
Abstract
Human sterile α motif and HD domain-containing protein 1 (SAMHD1), originally described as the major cellular deoxyribonucleoside triphosphate triphosphohydrolase (dNTPase) balancing the intracellular deoxynucleotide (dNTP) pool, has come recently into focus of cancer research. As outlined in this review, SAMHD1 has been reported to be mutated in a variety of cancer types and the expression of SAMHD1 is dysregulated in many cancers. Therefore, SAMHD1 is regarded as a tumor suppressor in certain tumors. Moreover, it has been proposed that SAMHD1 might fulfill the requirements of a driver gene in tumor development or might promote a so-called mutator phenotype. Besides its role as a dNTPase, several novel cellular functions of SAMHD1 have come to light only recently, including a role as negative regulator of innate immune responses and as facilitator of DNA end resection during DNA replication and repair. Therefore, SAMHD1 can be placed at the crossroads of various cellular processes. The present review summarizes the negative role of SAMHD1 in chemotherapy sensitivity, highlights reported SAMHD1 mutations found in various cancer types, and aims to discuss functional consequences as well as underlying mechanisms of SAMHD1 dysregulation potentially involved in cancer development.
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Affiliation(s)
- Kerstin Schott
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Catharina Majer
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Alla Bulashevska
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Liam Childs
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany
| | - Mirko H H Schmidt
- Institute of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden School of Medicine, Dresden, Germany
| | - Krishnaraj Rajalingam
- Cell Biology Unit, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- University Cancer Center Mainz, University Medical Center Mainz, Mainz, Germany
| | - Markus Munder
- Third Department of Medicine, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, Langen, Germany.
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13
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Martinat C, Cormier A, Tobaly-Tapiero J, Palmic N, Casartelli N, Mahboubi B, Coggins SA, Buchrieser J, Persaud M, Diaz-Griffero F, Espert L, Bossis G, Lesage P, Schwartz O, Kim B, Margottin-Goguet F, Saïb A, Zamborlini A. SUMOylation of SAMHD1 at Lysine 595 is required for HIV-1 restriction in non-cycling cells. Nat Commun 2021; 12:4582. [PMID: 34321470 PMCID: PMC8319325 DOI: 10.1038/s41467-021-24802-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 07/05/2021] [Indexed: 02/06/2023] Open
Abstract
SAMHD1 is a cellular triphosphohydrolase (dNTPase) proposed to inhibit HIV-1 reverse transcription in non-cycling immune cells by limiting the supply of the dNTP substrates. Yet, phosphorylation of T592 downregulates SAMHD1 antiviral activity, but not its dNTPase function, implying that additional mechanisms contribute to viral restriction. Here, we show that SAMHD1 is SUMOylated on residue K595, a modification that relies on the presence of a proximal SUMO-interacting motif (SIM). Loss of K595 SUMOylation suppresses the restriction activity of SAMHD1, even in the context of the constitutively active phospho-ablative T592A mutant but has no impact on dNTP depletion. Conversely, the artificial fusion of SUMO2 to a non-SUMOylatable inactive SAMHD1 variant restores its antiviral function, a phenotype that is reversed by the phosphomimetic T592E mutation. Collectively, our observations clearly establish that lack of T592 phosphorylation cannot fully account for the restriction activity of SAMHD1. We find that SUMOylation of K595 is required to stimulate a dNTPase-independent antiviral activity in non-cycling immune cells, an effect that is antagonized by cyclin/CDK-dependent phosphorylation of T592 in cycling cells.
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Affiliation(s)
- Charlotte Martinat
- INSERM U944, CNRS UMR 7212, Genomes & Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France
| | - Arthur Cormier
- INSERM U944, CNRS UMR 7212, Genomes & Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France
| | - Joëlle Tobaly-Tapiero
- INSERM U944, CNRS UMR 7212, Genomes & Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France
| | - Noé Palmic
- INSERM U944, CNRS UMR 7212, Genomes & Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France
| | - Nicoletta Casartelli
- grid.428999.70000 0001 2353 6535Institut Pasteur, Virus and Immunity Unit, CNRS-UMR3569, Paris, France ,grid.511001.4Vaccine Research Institute, Créteil, France
| | - Bijan Mahboubi
- grid.189967.80000 0001 0941 6502Emory School of Medicine, Atlanta, USA
| | - Si’Ana A. Coggins
- grid.189967.80000 0001 0941 6502Emory School of Medicine, Atlanta, USA
| | - Julian Buchrieser
- grid.428999.70000 0001 2353 6535Institut Pasteur, Virus and Immunity Unit, CNRS-UMR3569, Paris, France ,grid.511001.4Vaccine Research Institute, Créteil, France ,grid.4991.50000 0004 1936 8948James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Mirjana Persaud
- grid.251993.50000000121791997Albert Einstein College of Medicine, Microbiology and Immunology, Bronx, NY USA
| | - Felipe Diaz-Griffero
- grid.251993.50000000121791997Albert Einstein College of Medicine, Microbiology and Immunology, Bronx, NY USA
| | - Lucile Espert
- grid.503217.2IRIM, University of Montpellier, UMR 9004 CNRS, Montpellier, France
| | - Guillaume Bossis
- grid.429192.50000 0004 0599 0285IGMM, Univ Montpellier, CNRS, Montpellier, France
| | - Pascale Lesage
- INSERM U944, CNRS UMR 7212, Genomes & Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France
| | - Olivier Schwartz
- grid.428999.70000 0001 2353 6535Institut Pasteur, Virus and Immunity Unit, CNRS-UMR3569, Paris, France ,grid.511001.4Vaccine Research Institute, Créteil, France
| | - Baek Kim
- grid.189967.80000 0001 0941 6502Emory School of Medicine, Atlanta, USA
| | | | - Ali Saïb
- INSERM U944, CNRS UMR 7212, Genomes & Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France
| | - Alessia Zamborlini
- INSERM U944, CNRS UMR 7212, Genomes & Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France ,grid.457334.2Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
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14
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Yu CH, Bhattacharya A, Persaud M, Taylor AB, Wang Z, Bulnes-Ramos A, Xu J, Selyutina A, Martinez-Lopez A, Cano K, Demeler B, Kim B, Hardies SC, Diaz-Griffero F, Ivanov DN. Nucleic acid binding by SAMHD1 contributes to the antiretroviral activity and is enhanced by the GpsN modification. Nat Commun 2021; 12:731. [PMID: 33531504 PMCID: PMC7854603 DOI: 10.1038/s41467-021-21023-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 01/08/2021] [Indexed: 12/26/2022] Open
Abstract
SAMHD1 impedes infection of myeloid cells and resting T lymphocytes by retroviruses, and the enzymatic activity of the protein-dephosphorylation of deoxynucleotide triphosphates (dNTPs)-implicates enzymatic dNTP depletion in innate antiviral immunity. Here we show that the allosteric binding sites of the enzyme are plastic and can accommodate oligonucleotides in place of the allosteric activators, GTP and dNTP. SAMHD1 displays a preference for oligonucleotides containing phosphorothioate bonds in the Rp configuration located 3' to G nucleotides (GpsN), the modification pattern that occurs in a mechanism of antiviral defense in prokaryotes. In the presence of GTP and dNTPs, binding of GpsN-containing oligonucleotides promotes formation of a distinct tetramer with mixed occupancy of the allosteric sites. Mutations that impair formation of the mixed-occupancy complex abolish the antiretroviral activity of SAMHD1, but not its ability to deplete dNTPs. The findings link nucleic acid binding to the antiretroviral activity of SAMHD1, shed light on the immunomodulatory effects of synthetic phosphorothioated oligonucleotides and raise questions about the role of nucleic acid phosphorothioation in human innate immunity.
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Affiliation(s)
- Corey H Yu
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA
| | - Akash Bhattacharya
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA
| | - Mirjana Persaud
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Alexander B Taylor
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA
| | - Zhonghua Wang
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA
| | - Angel Bulnes-Ramos
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Joella Xu
- Department of Pediatrics, Emory School of Medicine, Atlanta, GA, USA
| | - Anastasia Selyutina
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Alicia Martinez-Lopez
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Kristin Cano
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA
| | - Borries Demeler
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, AB, Canada.,Department of Chemistry and Biochemistry, University of Montana, Missoula, MT, USA
| | - Baek Kim
- Department of Pediatrics, Emory School of Medicine, Atlanta, GA, USA
| | - Stephen C Hardies
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA
| | - Felipe Diaz-Griffero
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA.
| | - Dmitri N Ivanov
- Department of Biochemistry and Structural Biology, UT Health San Antonio, San Antonio, TX, USA.
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15
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Husain A, Xu J, Fujii H, Nakata M, Kobayashi M, Wang JY, Rehwinkel J, Honjo T, Begum NA. SAMHD1-mediated dNTP degradation is required for efficient DNA repair during antibody class switch recombination. EMBO J 2020; 39:e102931. [PMID: 32511795 DOI: 10.15252/embj.2019102931] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 05/04/2020] [Accepted: 05/08/2020] [Indexed: 12/12/2022] Open
Abstract
Sterile alpha motif and histidine-aspartic acid domain-containing protein 1 (SAMHD1), a dNTP triphosphohydrolase, regulates the levels of cellular dNTPs through their hydrolysis. SAMHD1 protects cells from invading viruses that depend on dNTPs to replicate and is frequently mutated in cancers and Aicardi-Goutières syndrome, a hereditary autoimmune encephalopathy. We discovered that SAMHD1 localizes at the immunoglobulin (Ig) switch region, and serves as a novel DNA repair regulator of Ig class switch recombination (CSR). Depletion of SAMHD1 impaired not only CSR but also IgH/c-Myc translocation. Consistently, we could inhibit these two processes by elevating the cellular nucleotide pool. A high frequency of nucleotide insertion at the break-point junctions is a notable feature in SAMHD1 deficiency during activation-induced cytidine deaminase-mediated genomic instability. Interestingly, CSR induced by staggered but not blunt, double-stranded DNA breaks was impaired by SAMHD1 depletion, which was accompanied by enhanced nucleotide insertions at recombination junctions. We propose that SAMHD1-mediated dNTP balance regulates dNTP-sensitive DNA end-processing enzyme and promotes CSR and aberrant genomic rearrangements by suppressing the insertional DNA repair pathway.
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Affiliation(s)
- Afzal Husain
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Jianliang Xu
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hodaka Fujii
- Department of Biochemistry and Genome Biology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan.,Combined Program on Microbiology and Immunology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Mikiyo Nakata
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Maki Kobayashi
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Ji-Yang Wang
- Department of Immunology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jan Rehwinkel
- Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Tasuku Honjo
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Nasim A Begum
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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16
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Restriction of exogenous DNA expression by SAMHD1. Sci Bull (Beijing) 2020; 65:573-586. [PMID: 36659189 DOI: 10.1016/j.scib.2019.12.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/09/2019] [Accepted: 11/19/2019] [Indexed: 01/21/2023]
Abstract
SAMHD1 (Sterile Alpha Motif and Histidine-aspartate Domain containing protein 1) has been documented as a host factor that restricts HIV-1 and some DNA viruses. In this work, we attempted to explore possible effects of SAMHD1 on exogenous DNA and show that SAMHD1 exerts a general inhibition on the expression of exogenous DNA in vitro and in mice. This inhibition is achieved through repressing transcription of exogenous DNA. Intriguingly, unlike SAMHD1's restriction of HIV-1, such restriction does not require the dNTPase or RNase activities, or T592 phosphorylation of SAMHD1. Mechanistically, SAMHD1 enhances the expression of interferon regulatory factor-1 (IRF1), while IRF1 upregulation was demonstrated to inhibit exogenous DNA expression in a similar fashion as SAMHD1. IFNλ1, whose induction has been associated with IRF1 activation, is dispensable for SAMHD1/IRF1-mediated restriction of exogenous DNA, and neither type I nor II interferons appear to be involved. We also demonstrate that SAMHD1/IRF1-mediated restriction can effectively inhibit hepatitis B virus (HBV) antigen expression and progeny virus production in mouse models. In conclusion, these data support restriction of exogenous DNA as a novel function of SAMHD1.
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17
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Wang C, Zhang K, Meng L, Zhang X, Song Y, Zhang Y, Gai Y, Zhang Y, Yu B, Wu J, Wang S, Yu X. The C-terminal domain of feline and bovine SAMHD1 proteins has a crucial role in lentiviral restriction. J Biol Chem 2020; 295:4252-4264. [PMID: 32075911 PMCID: PMC7105322 DOI: 10.1074/jbc.ra120.012767] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/14/2020] [Indexed: 01/29/2023] Open
Abstract
SAM and HD domain-containing protein 1 (SAMHD1) is a host factor that restricts reverse transcription of lentiviruses such as HIV in myeloid cells and resting T cells through its dNTP triphosphohydrolase (dNTPase) activity. Lentiviruses counteract this restriction by expressing the accessory protein Vpx or Vpr, which targets SAMHD1 for proteasomal degradation. SAMHD1 is conserved among mammals, and the feline and bovine SAMHD1 proteins (fSAM and bSAM) restrict lentiviruses by reducing cellular dNTP concentrations. However, the functional regions of fSAM and bSAM that are required for their biological functions are not well-characterized. Here, to establish alternative models to investigate SAMHD1 in vivo, we studied the restriction profile of fSAM and bSAM against different primate lentiviruses. We found that both fSAM and bSAM strongly restrict primate lentiviruses and that Vpx induces the proteasomal degradation of both fSAM and bSAM. Further investigation identified one and five amino acid sites in the C-terminal domain (CTD) of fSAM and bSAM, respectively, that are required for Vpx-mediated degradation. We also found that the CTD of bSAM is directly involved in mediating bSAM's antiviral activity by regulating dNTPase activity, whereas the CTD of fSAM is not. Our results suggest that the CTDs of fSAM and bSAM have important roles in their antiviral functions. These findings advance our understanding of the mechanism of fSAM- and bSAM-mediated viral restriction and might inform strategies for improving HIV animal models.
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Affiliation(s)
- Chu Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China; The First Hospital and Institute of Immunology, Jilin University, Changchun 130012, China
| | - Kaikai Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Lina Meng
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Xin Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yanan Song
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Ying Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yanxin Gai
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yuepeng Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Bin Yu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Jiaxin Wu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China
| | - Song Wang
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130012, China
| | - Xianghui Yu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun 130012, China.
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18
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Martín-Moreno A, Muñoz-Fernández MA. Dendritic Cells, the Double Agent in the War Against HIV-1. Front Immunol 2019; 10:2485. [PMID: 31708924 PMCID: PMC6820366 DOI: 10.3389/fimmu.2019.02485] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 10/04/2019] [Indexed: 12/19/2022] Open
Abstract
Human Immunodeficiency Virus (HIV) infects cells from the immune system and has thus developed tools to circumvent the host immunity and use it in its advance. Dendritic cells (DCs) are the first immune cells to encounter the HIV, and being the main antigen (Ag) presenting cells, they link the innate and the adaptive immune responses. While DCs work to promote an efficient immune response and halt the infection, HIV-1 has ways to take advantage of their role and uses DCs to gain faster and more efficient access to CD4+ T cells. Due to their ability to activate a specific immune response, DCs are promising candidates to achieve the functional cure of HIV-1 infection, but knowing the molecular partakers that determine the relationship between virus and cell is the key for the rational and successful design of a DC-based therapy. In this review, we summarize the current state of knowledge on how both DC subsets (myeloid and plasmacytoid DCs) act in presence of HIV-1, and focus on different pathways that the virus can take after binding to DC. First, we explore the consequences of HIV-1 recognition by each receptor on DCs, including CD4 and DC-SIGN. Second, we look at cellular mechanisms that prevent productive infection and weapons that turn cellular defense into a Trojan horse that hides the virus all the way to T cell. Finally, we discuss the possible outcomes of DC-T cell contact.
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Affiliation(s)
- Alba Martín-Moreno
- Sección de Inmunología, Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón (HGUGM), Madrid, Spain.,Instituto Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Mª Angeles Muñoz-Fernández
- Sección de Inmunología, Laboratorio InmunoBiología Molecular, Hospital General Universitario Gregorio Marañón (HGUGM), Madrid, Spain.,Instituto Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Spanish HIV-HGM BioBank, Madrid, Spain.,Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER BBN), Madrid, Spain
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19
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Oellerich T, Schneider C, Thomas D, Knecht KM, Buzovetsky O, Kaderali L, Schliemann C, Bohnenberger H, Angenendt L, Hartmann W, Wardelmann E, Rothenburger T, Mohr S, Scheich S, Comoglio F, Wilke A, Ströbel P, Serve H, Michaelis M, Ferreirós N, Geisslinger G, Xiong Y, Keppler OT, Cinatl J. Selective inactivation of hypomethylating agents by SAMHD1 provides a rationale for therapeutic stratification in AML. Nat Commun 2019; 10:3475. [PMID: 31375673 PMCID: PMC6677770 DOI: 10.1038/s41467-019-11413-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 07/08/2019] [Indexed: 02/08/2023] Open
Abstract
Hypomethylating agents decitabine and azacytidine are regarded as interchangeable in the treatment of acute myeloid leukemia (AML). However, their mechanisms of action remain incompletely understood, and predictive biomarkers for HMA efficacy are lacking. Here, we show that the bioactive metabolite decitabine triphosphate, but not azacytidine triphosphate, functions as activator and substrate of the triphosphohydrolase SAMHD1 and is subject to SAMHD1-mediated inactivation. Retrospective immunohistochemical analysis of bone marrow specimens from AML patients at diagnosis revealed that SAMHD1 expression in leukemic cells inversely correlates with clinical response to decitabine, but not to azacytidine. SAMHD1 ablation increases the antileukemic activity of decitabine in AML cell lines, primary leukemic blasts, and xenograft models. AML cells acquire resistance to decitabine partly by SAMHD1 up-regulation. Together, our data suggest that SAMHD1 is a biomarker for the stratified use of hypomethylating agents in AML patients and a potential target for the treatment of decitabine-resistant leukemia. In acute myeloid leukemia, hypomethylating agents decitabine and azacytidine are used interchangeably. Here, the authors show that the major metabolite of decitabine, but not azacytidine, is subject to SAMHD1 inactivation, highlighting SAMHD1 as a potential biomarker and therapeutic target
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Affiliation(s)
- Thomas Oellerich
- Department of Medicine II, Hematology/Oncology, Goethe University of Frankfurt, Frankfurt, 60590, Germany.,German Cancer Consortium/German Cancer Research Center, Heidelberg, 69120, Germany.,Frankfurt Cancer Institute, Goethe University Frankfurt, Frankfurt, 60596, Germany
| | - Constanze Schneider
- Department of Medicine II, Hematology/Oncology, Goethe University of Frankfurt, Frankfurt, 60590, Germany.,Frankfurt Cancer Institute, Goethe University Frankfurt, Frankfurt, 60596, Germany.,Institute of Medical Virology, University of Frankfurt, Frankfurt, 60590, Germany
| | - Dominique Thomas
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe University of Frankfurt, Frankfurt, 60590, Germany
| | - Kirsten M Knecht
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Olga Buzovetsky
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Lars Kaderali
- Institute of Bioinformatics, University Medicine Greifswald, Greifswald, 17475, Germany
| | | | | | - Linus Angenendt
- Department of Medicine A, University Hospital Münster, Münster, 48149, Germany
| | - Wolfgang Hartmann
- Gerhard Domagk Institute for Pathology, University Hospital Münster, Münster, 48149, Germany
| | - Eva Wardelmann
- Gerhard Domagk Institute for Pathology, University Hospital Münster, Münster, 48149, Germany
| | - Tamara Rothenburger
- Institute of Medical Virology, University of Frankfurt, Frankfurt, 60590, Germany
| | - Sebastian Mohr
- Department of Medicine II, Hematology/Oncology, Goethe University of Frankfurt, Frankfurt, 60590, Germany
| | - Sebastian Scheich
- Department of Medicine II, Hematology/Oncology, Goethe University of Frankfurt, Frankfurt, 60590, Germany
| | - Federico Comoglio
- Department of Haematology, Cambridge Institute of Medical Research, Cambridge University, Cambridge, CB2 0XY, UK
| | - Anne Wilke
- Department of Medicine II, Hematology/Oncology, Goethe University of Frankfurt, Frankfurt, 60590, Germany
| | - Philipp Ströbel
- Institute of Pathology, University Medical Center, Göttingen, 37075, Germany
| | - Hubert Serve
- Department of Medicine II, Hematology/Oncology, Goethe University of Frankfurt, Frankfurt, 60590, Germany.,German Cancer Consortium/German Cancer Research Center, Heidelberg, 69120, Germany.,Frankfurt Cancer Institute, Goethe University Frankfurt, Frankfurt, 60596, Germany
| | - Martin Michaelis
- Industrial Biotechnology Centre and School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK
| | - Nerea Ferreirós
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe University of Frankfurt, Frankfurt, 60590, Germany
| | - Gerd Geisslinger
- pharmazentrum frankfurt/ZAFES, Institute of Clinical Pharmacology, Goethe University of Frankfurt, Frankfurt, 60590, Germany.,Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Project group Translational Medicine and Pharmacology (TMP), Frankfurt, 60596, Germany
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Oliver T Keppler
- Institute of Medical Virology, University of Frankfurt, Frankfurt, 60590, Germany. .,Max von Pettenkofer Institute, Virology, Faculty of Medicine, LMU München, Munich, 80336, Germany.
| | - Jindrich Cinatl
- Institute of Medical Virology, University of Frankfurt, Frankfurt, 60590, Germany.
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20
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The missing link: allostery and catalysis in the anti-viral protein SAMHD1. Biochem Soc Trans 2019; 47:1013-1027. [PMID: 31296733 PMCID: PMC7045340 DOI: 10.1042/bst20180348] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/11/2022]
Abstract
Vertebrate protein SAMHD1 (sterile-α-motif and HD domain containing protein 1) regulates the cellular dNTP (2′-deoxynucleoside-5′-triphosphate) pool by catalysing the hydrolysis of dNTP into 2′-deoxynucleoside and triphosphate products. As an important regulator of cell proliferation and a key player in dNTP homeostasis, mutations to SAMHD1 are implicated in hypermutated cancers, and germline mutations are associated with Chronic Lymphocytic Leukaemia and the inflammatory disorder Aicardi–Goutières Syndrome. By limiting the supply of dNTPs for viral DNA synthesis, SAMHD1 also restricts the replication of several retroviruses, such as HIV-1, and some DNA viruses in dendritic and myeloid lineage cells and resting T-cells. SAMHD1 activity is regulated throughout the cell cycle, both at the level of protein expression and post-translationally, through phosphorylation. In addition, allosteric regulation further fine-tunes the catalytic activity of SAMHD1, with a nucleotide-activated homotetramer as the catalytically active form of the protein. In cells, GTP and dATP are the likely physiological activators of two adjacent allosteric sites, AL1 (GTP) and AL2 (dATP), that bridge monomer–monomer interfaces to stabilise the protein homotetramer. This review summarises the extensive X-ray crystallographic, biophysical and molecular dynamics experiments that have elucidated important features of allosteric regulation in SAMHD1. We present a comprehensive mechanism detailing the structural and protein dynamics components of the allosteric coupling between nucleotide-induced tetramerization and the catalysis of dNTP hydrolysis by SAMHD1.
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21
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Patra KK, Bhattacharya A, Bhattacharya S. Molecular dynamics investigation of a redox switch in the anti-HIV protein SAMHD1. Proteins 2019; 87:748-759. [PMID: 31017331 DOI: 10.1002/prot.25701] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/11/2019] [Accepted: 04/22/2019] [Indexed: 12/17/2022]
Abstract
HIV-1 is restricted in macrophages and certain quiescent myeloid cells due to a "Scorched Earth" dNTP starvation strategy attributed to the sterile alpha motif and HD domain protein-SAMHD1. Active SAMHD1 tetramers are assembled by GTP-Mg+2-dNTP cross bridges and cleave the triphosphate groups of dNTPs at a K m of ~10 μM, which is consistent with dNTP concentrations in cycling cells, but far higher than the equivalent concentration in quiescent cells. Given the substantial disparity between the dNTP concentrations required to activate SAMHD1 tetramers (~10 μM) and the dNTP concentrations in noncycling cells (~10 nM), the possibility of alternate enzymatically active forms of SAMHD1, including monomers remains open. In particular, the possibility of redox regulation of such monomers is also an open question. There have been experimental studies on the regulation of SAMHD1 by Glutathione driven redox reactions recently. Therefore, in this work, we have performed all-atom molecular dynamics simulations to study the dynamics of monomeric SAMHD1 constructs in the context of the three redox-susceptible Cysteine residues and compared them to monomers assembled within a tetramer. Our results indicate that assembly into a tetramer causes ordering of the catalytic core and increased solvent accessibility of the Catalytic Site. We have also found that glutathionylation of surface exposed C522 causes long range allosteric disruptions extending into the protein core. Finally, we see evidence suggesting a transient interaction between C522 and C341. Such a disulfide linkage has been hypothesized by experimental models, but has never been observed in crystal structures before.
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Affiliation(s)
- Kajwal Kumar Patra
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Akash Bhattacharya
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Swati Bhattacharya
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
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22
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Wing PA, Davenne T, Wettengel J, Lai AG, Zhuang X, Chakraborty A, D'Arienzo V, Kramer C, Ko C, Harris JM, Schreiner S, Higgs M, Roessler S, Parish JL, Protzer U, Balfe P, Rehwinkel J, McKeating JA. A dual role for SAMHD1 in regulating HBV cccDNA and RT-dependent particle genesis. Life Sci Alliance 2019; 2:e201900355. [PMID: 30918010 PMCID: PMC6438393 DOI: 10.26508/lsa.201900355] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/15/2019] [Accepted: 03/18/2019] [Indexed: 02/06/2023] Open
Abstract
Chronic hepatitis B is one of the world's unconquered diseases with more than 240 million infected subjects at risk of developing liver disease and hepatocellular carcinoma. Hepatitis B virus reverse transcribes pre-genomic RNA to relaxed circular DNA (rcDNA) that comprises the infectious particle. To establish infection of a naïve target cell, the newly imported rcDNA is repaired by host enzymes to generate covalently closed circular DNA (cccDNA), which forms the transcriptional template for viral replication. SAMHD1 is a component of the innate immune system that regulates deoxyribonucleoside triphosphate levels required for host and viral DNA synthesis. Here, we show a positive role for SAMHD1 in regulating cccDNA formation, where KO of SAMHD1 significantly reduces cccDNA levels that was reversed by expressing wild-type but not a mutated SAMHD1 lacking the nuclear localization signal. The limited pool of cccDNA in infected Samhd1 KO cells is transcriptionally active, and we observed a 10-fold increase in newly synthesized rcDNA-containing particles, demonstrating a dual role for SAMHD1 to both facilitate cccDNA genesis and to restrict reverse transcriptase-dependent particle genesis.
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Affiliation(s)
- Peter Ac Wing
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Tamara Davenne
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jochen Wettengel
- Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Munich, Germany
| | - Alvina G Lai
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Xiaodong Zhuang
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Anindita Chakraborty
- Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Munich, Germany
| | | | - Catharina Kramer
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chunkyu Ko
- Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Munich, Germany
| | - James M Harris
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sabrina Schreiner
- Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Munich, Germany
- German Center for Infection Research (DZIF), Munich Partner Site, Munich, Germany
| | - Martin Higgs
- Institutes of Cancer and Genomic Sciences and Immunity and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, UK
| | - Stephanie Roessler
- Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany
| | - Joanna L Parish
- Institutes of Cancer and Genomic Sciences and Immunity and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, UK
| | - Ulrike Protzer
- Institute of Virology, Technische Universität München/Helmholtz Zentrum München, Munich, Germany
- German Center for Infection Research (DZIF), Munich Partner Site, Munich, Germany
| | - Peter Balfe
- Institutes of Cancer and Genomic Sciences and Immunity and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, UK
| | - Jan Rehwinkel
- Medical Research Council Human Immunology Unit, Medical Research Council Weatherall Institute of Molecular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Jane A McKeating
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
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23
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Majer C, Schüssler JM, König R. Intertwined: SAMHD1 cellular functions, restriction, and viral evasion strategies. Med Microbiol Immunol 2019; 208:513-529. [PMID: 30879196 DOI: 10.1007/s00430-019-00593-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 03/08/2019] [Indexed: 01/01/2023]
Abstract
SAMHD1 was initially described for its ability to efficiently restrict HIV-1 replication in myeloid cells and resting CD4+ T cells. However, a growing body of evidence suggests that SAMHD1-mediated restriction is by far not limited to lentiviruses, but seems to be a general concept that applies to most retroviruses and at least a number of DNA viruses. SAMHD1 anti-viral activity was long believed to be solely due to its ability to deplete cellular dNTPs by enzymatic degradation. However, since its discovery, several new functions have been attributed to SAMHD1. It has been demonstrated to bind nucleic acids, to modulate innate immunity, as well as to participate in the DNA damage response and resolution of stalled replication forks. Consequently, it is likely that SAMHD1-mediated anti-viral activity is not or not exclusively mediated through its dNTPase activity. Therefore, in this review, we summarize current knowledge on SAMHD1 cellular functions and systematically discuss how these functions could contribute to the restriction of a broad range of viruses besides retroviruses: herpesviruses, poxviruses and hepatitis B virus. Furthermore, we aim to highlight different ways how viruses counteract SAMHD1-mediated restriction to bypass the SAMHD1-mediated block to viral infection.
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Affiliation(s)
- Catharina Majer
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany
| | | | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany. .,Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA. .,German Center for Infection Research (DZIF), 63225, Langen, Germany. .,Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany.
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24
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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] [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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25
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Chen L, Keppler OT, Schölz C. Post-translational Modification-Based Regulation of HIV Replication. Front Microbiol 2018; 9:2131. [PMID: 30254620 PMCID: PMC6141784 DOI: 10.3389/fmicb.2018.02131] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/20/2018] [Indexed: 12/13/2022] Open
Abstract
Human immunodeficiency virus (HIV) relies heavily on the host cellular machinery for production of viral progeny. To exploit cellular proteins for replication and to overcome host factors with antiviral activity, HIV has evolved a set of regulatory and accessory proteins to shape an optimized environment for its replication and to facilitate evasion from the immune system. Several cellular pathways are hijacked by the virus to modulate critical steps during the viral life cycle. Thereby, post-translational modifications (PTMs) of viral and cellular proteins gain increasingly attention as modifying enzymes regulate virtually every step of the viral replication cycle. This review summarizes the current knowledge of HIV-host interactions influenced by PTMs with a special focus on acetylation, ubiquitination, and phosphorylation of proteins linked to cellular signaling and viral replication. Insights into these interactions are surmised to aid development of new intervention strategies.
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Affiliation(s)
- Lin Chen
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Oliver T Keppler
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Christian Schölz
- Max von Pettenkofer-Institute and Gene Center, Virology, National Reference Center for Retroviruses, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
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26
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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: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [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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27
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Schott K, Fuchs NV, Derua R, Mahboubi B, Schnellbächer E, Seifried J, Tondera C, Schmitz H, Shepard C, Brandariz-Nuñez A, Diaz-Griffero F, Reuter A, Kim B, Janssens V, König R. Dephosphorylation of the HIV-1 restriction factor SAMHD1 is mediated by PP2A-B55α holoenzymes during mitotic exit. Nat Commun 2018; 9:2227. [PMID: 29884836 PMCID: PMC5993806 DOI: 10.1038/s41467-018-04671-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 05/15/2018] [Indexed: 12/20/2022] Open
Abstract
SAMHD1 is a critical restriction factor for HIV-1 in non-cycling cells and its antiviral activity is regulated by T592 phosphorylation. Here, we show that SAMHD1 dephosphorylation at T592 is controlled during the cell cycle, occurring during M/G1 transition in proliferating cells. Using several complementary proteomics and biochemical approaches, we identify the phosphatase PP2A-B55α responsible for rendering SAMHD1 antivirally active. SAMHD1 is specifically targeted by PP2A-B55α holoenzymes during mitotic exit, in line with observations that PP2A-B55α is a key mitotic exit phosphatase in mammalian cells. Strikingly, as HeLa or activated primary CD4+ T cells enter the G1 phase, pronounced reduction of RT products is observed upon HIV-1 infection dependent on the presence of dephosphorylated SAMHD1. Moreover, PP2A controls SAMHD1 pT592 level in non-cycling monocyte-derived macrophages (MDMs). Thus, the PP2A-B55α holoenzyme is a key regulator to switch on the antiviral activity of SAMHD1.
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Affiliation(s)
- Kerstin Schott
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Nina V Fuchs
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Rita Derua
- Department of Cellular and Molecular Medicine, Laboratory of Protein Phosphorylation and Proteomics, KU Leuven, 3000, Leuven, Belgium.,Facility for Systems Biology based Mass Spectrometry (SYBIOMA), KU Leuven, 3000, Leuven, Belgium
| | - Bijan Mahboubi
- Center for Drug Discovery, Department of Pediatrics, Emory University, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | | | - Janna Seifried
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Christiane Tondera
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Heike Schmitz
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Caitlin Shepard
- Center for Drug Discovery, Department of Pediatrics, Emory University, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Alberto Brandariz-Nuñez
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Felipe Diaz-Griffero
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Andreas Reuter
- Division of Allergology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Baek Kim
- Center for Drug Discovery, Department of Pediatrics, Emory University, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA.,Department of Pharmacy, Kyung-Hee University, 2447, Seoul, South Korea
| | - Veerle Janssens
- Department of Cellular and Molecular Medicine, Laboratory of Protein Phosphorylation and Proteomics, KU Leuven, 3000, Leuven, Belgium
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institut, 63225, Langen, Germany. .,Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA. .,German Center for Infection Research (DZIF), 63225, Langen, Germany.
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28
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SAMHD1 Promotes DNA End Resection to Facilitate DNA Repair by Homologous Recombination. Cell Rep 2018; 20:1921-1935. [PMID: 28834754 DOI: 10.1016/j.celrep.2017.08.008] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/05/2017] [Accepted: 07/28/2017] [Indexed: 12/28/2022] Open
Abstract
DNA double-strand break (DSB) repair by homologous recombination (HR) is initiated by CtIP/MRN-mediated DNA end resection to maintain genome integrity. SAMHD1 is a dNTP triphosphohydrolase, which restricts HIV-1 infection, and mutations are associated with Aicardi-Goutières syndrome and cancer. We show that SAMHD1 has a dNTPase-independent function in promoting DNA end resection to facilitate DSB repair by HR. SAMHD1 deficiency or Vpx-mediated degradation causes hypersensitivity to DSB-inducing agents, and SAMHD1 is recruited to DSBs. SAMHD1 complexes with CtIP via a conserved C-terminal domain and recruits CtIP to DSBs to facilitate end resection and HR. Significantly, a cancer-associated mutant with impaired CtIP interaction, but not dNTPase-inactive SAMHD1, fails to rescue the end resection impairment of SAMHD1 depletion. Our findings define a dNTPase-independent function for SAMHD1 in HR-mediated DSB repair by facilitating CtIP accrual to promote DNA end resection, providing insight into how SAMHD1 promotes genome integrity.
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29
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Mauney CH, Hollis T. SAMHD1: Recurring roles in cell cycle, viral restriction, cancer, and innate immunity. Autoimmunity 2018; 51:96-110. [PMID: 29583030 PMCID: PMC6117824 DOI: 10.1080/08916934.2018.1454912] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 03/16/2018] [Indexed: 12/24/2022]
Abstract
Sterile alpha motif and histidine-aspartic acid domain-containing protein 1 (SAMHD1) is a deoxynucleotide triphosphate (dNTP) hydrolase that plays an important role in the homeostatic balance of cellular dNTPs. Its emerging role as an effector of innate immunity is affirmed by mutations in the SAMHD1 gene that cause the severe autoimmune disease, Aicardi-Goutieres syndrome (AGS) and that are linked to cancer. Additionally, SAMHD1 functions as a restriction factor for retroviruses, such as HIV. Here, we review the current biochemical and biological properties of the enzyme including its structure, activity, and regulation by post-translational modifications in the context of its cellular function. We outline open questions regarding the biology of SAMHD1 whose answers will be important for understanding its function as a regulator of cell cycle progression, genomic integrity, and in autoimmunity.
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Affiliation(s)
- Christopher H Mauney
- a Department of Biochemistry , Center for Structural Biology, Wake Forest School of Medicine , Winston Salem , NC , USA
| | - Thomas Hollis
- a Department of Biochemistry , Center for Structural Biology, Wake Forest School of Medicine , Winston Salem , NC , USA
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30
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Abstract
Monocyte-derived macrophages (MDMs) are an important target for HIV-1 despite SAMHD1, a myeloid restriction factor for which HIV-1 lacks a counteracting accessory protein. The antiviral activity of SAMHD1 is modulated by phosphorylation of T592 by cyclin-dependent kinases (CDK). We show that treatment of MDMs with neocarzinostatin, a compound that introduces double strand breaks (DBS) in genomic DNA, results in the decrease of phosphorylated SAMHD1, activating its antiviral activity and blocking HIV-1 infection. The effect was specific for DSB as DNA damage induced by UV light irradiation did not affect SAMHD1 phosphorylation and did not block infection. The block to infection was at reverse transcription and was counteracted by Vpx, demonstrating that it was caused by SAMHD1. Neocarzinostatin treatment also activated an innate immune response that induced interferon-stimulated genes but this was not involved in the block to HIV-1 infection, as it was not relieved by an interferon-blocking antibody. In response to Neocarzinostatin-induced DNA damage, the level of the CDK inhibitor p21cip1 increased which could account for the decrease of phosphorylated SAMHD1. The results show that the susceptibility of MDMs to HIV-1 infection can be affected by stimuli that alter the phosphorylation state of SAMHD1, one of which is the DNA damage response.
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Affiliation(s)
- Paula Jáuregui
- Department of Microbiology, NYU School of Medicine, Smilow Research Building, Rm. 1003, 550 First Avenue, New York, 10016, USA
| | - Nathaniel R Landau
- Department of Microbiology, NYU School of Medicine, Smilow Research Building, Rm. 1003, 550 First Avenue, New York, 10016, USA.
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31
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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] [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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32
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Sumner RP, Thorne LG, Fink DL, Khan H, Milne RS, Towers GJ. Are Evolution and the Intracellular Innate Immune System Key Determinants in HIV Transmission? Front Immunol 2017; 8:1246. [PMID: 29056936 PMCID: PMC5635324 DOI: 10.3389/fimmu.2017.01246] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 09/19/2017] [Indexed: 01/05/2023] Open
Abstract
HIV-1 is the single most important sexually transmitted disease in humans from a global health perspective. Among human lentiviruses, HIV-1 M group has uniquely achieved pandemic levels of human-to-human transmission. The requirement to transmit between hosts likely provides the strongest selective forces on a virus, as without transmission, there can be no new infections within a host population. Our perspective is that evolution of all of the virus-host interactions, which are inherited and perpetuated from host-to-host, must be consistent with transmission. For example, CXCR4 use, which often evolves late in infection, does not favor transmission and is therefore lost when a virus transmits to a new host. Thus, transmission inevitably influences all aspects of virus biology, including interactions with the innate immune system, and dictates the biological niche in which the virus exists in the host. A viable viral niche typically does not select features that disfavor transmission. The innate immune response represents a significant selective pressure during the transmission process. In fact, all viruses must antagonize and/or evade the mechanisms of the host innate and adaptive immune systems that they encounter. We believe that viewing host-virus interactions from a transmission perspective helps us understand the mechanistic details of antiviral immunity and viral escape. This is particularly true for the innate immune system, which typically acts from the very earliest stages of the host-virus interaction, and must be bypassed to achieve successful infection. With this in mind, here we review the innate sensing of HIV, the consequent downstream signaling cascades and the viral restriction that results. The centrality of these mechanisms to host defense is illustrated by the array of countermeasures that HIV deploys to escape them, despite the coding constraint of a 10 kb genome. We consider evasion strategies in detail, in particular the role of the HIV capsid and the viral accessory proteins highlighting important unanswered questions and discussing future perspectives.
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Affiliation(s)
- Rebecca P. Sumner
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Lucy G. Thorne
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Doug L. Fink
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Hataf Khan
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Richard S. Milne
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Greg J. Towers
- Division of Infection and Immunity, University College London, London, United Kingdom
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Herold N, Rudd SG, Sanjiv K, Kutzner J, Myrberg IH, Paulin CBJ, Olsen TK, Helleday T, Henter JI, Schaller T. With me or against me: Tumor suppressor and drug resistance activities of SAMHD1. Exp Hematol 2017; 52:32-39. [PMID: 28502830 DOI: 10.1016/j.exphem.2017.05.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 04/29/2017] [Accepted: 05/02/2017] [Indexed: 01/04/2023]
Abstract
Sterile alpha motif and histidine/aspartic acid domain-containing protein 1 (SAMHD1) is a (deoxy)guanosine triphosphate (dGTP/GTP)-activated deoxyribonucleoside triphosphate (dNTP) triphosphohydrolase involved in cellular dNTP homoeostasis. Mutations in SAMHD1 have been associated with the hyperinflammatory disease Aicardi-Goutières syndrome (AGS). SAMHD1 also limits cells' permissiveness to infection with diverse viruses, including human immunodeficiency virus (HIV-1), and controls endogenous retroviruses. Increasing evidence supports the role of SAMHD1 as a tumor suppressor. However, SAMHD1 also can act as a resistance factor to nucleoside-based chemotherapies by hydrolyzing their active triphosphate metabolites, thereby reducing response of various malignancies to these anticancer drugs. Hence, informed cancer therapies must take into account the ambiguous properties of SAMHD1 as both an inhibitor of uncontrolled proliferation and a resistance factor limiting the efficacy of anticancer treatments. Here, we provide evidence that SAMHD1 is a double-edged sword for patients with acute myelogenous leukemia (AML). Our time-dependent analyses of The Cancer Genome Atlas (TCGA) AML cohort indicate that high expression of SAMHD1, even though it critically limits the efficacy of high-dose ara-C therapy, might be associated with more favorable disease progression.
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Affiliation(s)
- Nikolas Herold
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Theme of Children's and Women's Health, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
| | - Sean G Rudd
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Kumar Sanjiv
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Juliane Kutzner
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany
| | - Ida Hed Myrberg
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden
| | - Cynthia B J Paulin
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Thale Kristin Olsen
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden
| | - Thomas Helleday
- Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Jan-Inge Henter
- Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Theme of Children's and Women's Health, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Torsten Schaller
- Department of Infectious Diseases, Virology, University Hospital Heidelberg, Heidelberg, Germany.
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34
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Li M, Zhang D, Zhu M, Shen Y, Wei W, Ying S, Korner H, Li J. Roles of SAMHD1 in antiviral defense, autoimmunity and cancer. Rev Med Virol 2017; 27. [PMID: 28444859 DOI: 10.1002/rmv.1931] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 02/26/2017] [Accepted: 03/13/2017] [Indexed: 01/02/2023]
Abstract
The enzyme, sterile α motif and histidine-aspartic acid domain-containing protein 1 (SAMHD1) diminishes infection of human immunodeficiency virus type 1 (HIV-1) by hydrolyzing intracellular deoxynucleotide triphosphates (dNTPs) in myeloid cells and resting CD4+ T cells. This dNTP degradation reduces the dNTP concentration to a level insufficient for viral cDNA synthesis, thereby inhibiting retroviral replication. This antiviral enzymatic activity can be inhibited by viral protein X (Vpx). The HIV-2/SIV Vpx causes degradation of SAMHD1, thus interfering with the SAMHD1-mediated restriction of retroviral replication. Recently, SAMHD1 has been suggested to restrict HIV-1 infection by directly digesting genomic HIV-1 RNA through a still controversial RNase activity. Here, we summarize the current knowledge about structure, antiviral mechanisms, intracellular localization, interferon-regulated expression of SAMHD1. We also describe SAMHD1-deficient animal models and an antiviral drug on the basis of disrupting proteasomal degradation of SAMHD1. In addition, the possible roles of SAMHD1 in regulating innate immune sensing, Aicardi-Goutières syndrome and cancer are discussed in this review.
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Affiliation(s)
- Miaomiao Li
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province, PR China
| | - Dong Zhang
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province, PR China.,School of Basic Medical Sciences and Biopharmaceutical Research Institute, Anhui Medical University, Hefei, Anhui Province, PR China
| | - Mengying Zhu
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province, PR China
| | - Yuxian Shen
- School of Basic Medical Sciences and Biopharmaceutical Research Institute, Anhui Medical University, Hefei, Anhui Province, PR China
| | - Wei Wei
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Hefei, Anhui Province, PR China
| | - Songcheng Ying
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, Anhui Province, PR China.,School of Pharmacy, Anhui Medical University, Hefei, Anhui Province, PR China
| | - Heinrich Korner
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Hefei, Anhui Province, PR China.,Menzies Institute for Medical Research Tasmania, Hobart, Tasmania, Australia
| | - Jun Li
- School of Pharmacy, Anhui Medical University, Hefei, Anhui Province, PR China
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35
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Schott K, Riess M, König R. Role of Innate Genes in HIV Replication. Curr Top Microbiol Immunol 2017; 419:69-111. [PMID: 28685292 DOI: 10.1007/82_2017_29] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cells use an elaborate innate immune surveillance and defense system against virus infections. Here, we discuss recent studies that reveal how HIV-1 is sensed by the innate immune system. Furthermore, we present mechanisms on the counteraction of HIV-1. We will provide an overview how HIV-1 actively utilizes host cellular factors to avoid sensing. Additionally, we will summarize effectors of the innate response that provide an antiviral cellular state. HIV-1 has evolved passive mechanism to avoid restriction and to regulate the innate response. We review in detail two prominent examples of these cellular factors: (i) NLRX1, a negative regulator of the innate response that HIV-1 actively usurps to block cytosolic innate sensing; (ii) SAMHD1, a restriction factor blocking the virus at the reverse transcription step that HIV-1 passively avoids to escape sensing.
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Affiliation(s)
- Kerstin Schott
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany
| | - Maximilian Riess
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, 63225, Langen, Germany. .,Immunity and Pathogenesis Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA. .,German Center for Infection Research (DZIF), 63225, Langen, Germany.
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