RESEARCH ARTICLE

Dephosphorylation of cGAS by PPP6C impairs its substrate binding activity and innate antiviral response

  • Mi Li ,
  • Hong-Bing Shu
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  • Department of Infectious Diseases, Frontier Science Center for Immunology and Metabolism, Medical Research Institute, Zhongnan Hospital of Wuhan University, College of Life Sciences, Wuhan University, Wuhan 430071, China

Received date: 29 Mar 2020

Accepted date: 24 Apr 2020

Published date: 15 Aug 2020

Copyright

2020 The Author(s) 2020

Abstract

The cyclic GMP-AMP (cGAMP) synthase (cGAS) plays a critical role in host defense by sensing cytosolic DNA derived from microbial pathogens or mis-located cellular DNA. Upon DNA binding, cGAS utilizes GTP and ATP as substrates to synthesize cGAMP, leading to MITA-mediated innate immune response. In this study, we identified the phosphatase PPP6C as a negative regulator of cGASmediated innate immune response. PPP6C is constitutively associated with cGAS in un-stimulated cells. DNA virus infection causes rapid disassociation of PPP6C from cGAS, resulting in phosphorylation of human cGAS S435 or mouse cGAS S420 in its catalytic pocket. Mutation of this serine residue of cGAS impairs its ability to synthesize cGAMP upon DNA virus infection. In vitro experiments indicate that S420-phosphorylated mcGAS has higher affinity to GTP and enzymatic activity. PPP6Cdeficiency promotes innate immune response to DNA virus in various cells. Our findings suggest that PPP6Cmediated dephosphorylation of a catalytic pocket serine residue of cGAS impairs its substrate binding activity and innate immune response, which provides a mechanism for keeping the DNA sensor cGAS inactive in the absence of infection to avoid autoimmune response.

Cite this article

Mi Li , Hong-Bing Shu . Dephosphorylation of cGAS by PPP6C impairs its substrate binding activity and innate antiviral response[J]. Protein & Cell, 2020 , 11(8) : 584 -599 . DOI: 10.1007/s13238-020-00729-3

1
Akira S, Uematsu S, Takeuchi O (2006) Pathogen recognition and innate immunity. Cell 124:783–801

DOI

2
An J, Durcan L, Karr RM, Briggs TA, Rice GI, Teal TH, Woodward JJ, Elkon KB (2017) Expression of cyclic GMP-AMP synthase in patients with systemic lupus erythematosus. Arthritis Rheumatol 69:800–807

DOI

3
Bonilla X, Parmentier L, King B, Bezrukov F, Kaya G, Zoete V, Seplyarskiy VB, Sharpe HJ, McKee T, Letourneau A (2016) Genomic analysis identifies new drivers and progression pathways in skin basal cell carcinoma. Nat Genet 48:398–406

DOI

4
Brautigan DL, Shenolikar S (2018) Protein serine/threonine phosphatases: keys to unlocking regulators and substrates. Annu Rev Biochem 87:921–964

DOI

5
Dai J, Huang YJ, He X, Zhao M, Wang X, Liu ZS, Xue W, Cai H, Zhan XY, Huang SY(2019) Acetylation blocks cGAS activity and inhibits self-DNA-induced autoimmunity. Cell 176(1447–1460):e1414

DOI

6
Fang C, Wei X, Wei Y (2016) Mitochondrial DNA in the regulation of innate immune responses. Protein Cell 7:11–16

DOI

7
Gao P, Ascano M, Wu Y, Barchet W, Gaffney BL, Zillinger T, Serganov AA, Liu Y, Jones RA, Hartmann G (2013) Cyclic [G (2’,5’)pA(3’,5’)p] is the metazoan second messenger produced by DNA-activated cyclic GMP-AMP synthase. Cell 153:1094–1107

DOI

8
Gray EE, Treuting PM, Woodward JJ, Stetson DB (2015) Cutting edge: cGAS is required for lethal autoimmune disease in the Trex1-deficient mouse model of aicardi-goutieres syndrome.J Immunol 195:1939–1943

DOI

9
Harding SM, Benci JL, Irianto J, Discher DE, Minn AJ, Greenberg RA (2017) Mitotic progression following DNA damage enables pattern recognition within micronuclei. Nature 548:466–470

DOI

10
Hiratsuka T (1975) 2’ (or 3’)-O-(2, 4, 6-trinitrophenyl)adenosine 5’-triphosphate as a probe for the binding site of heavy meromyosin ATPase. J Biochem 78:1135–1147

DOI

11
Hodis E, Watson IR, Kryukov GV, Arold ST, Imielinski M, Theurillat JP, Nickerson E, Auclair D, Li L, Place C (2012) A landscape of driver mutations in melanoma. Cell 150:251–263

DOI

12
Hooy R, Sohn J (2019) A pyrophosphatase-coupled assay to monitor the NTase activity of cGAS. Methods Enzymol 625:77–86

DOI

13
Hosing AS, Valerie NC, Dziegielewski J, Brautigan DL, Larner JM (2012) PP6 regulatory subunit R1 is bidentate anchor for targeting protein phosphatase-6 to DNA-dependent protein kinase. J Biol Chem 287:9230–9239

DOI

14
Hu MM, Shu HB (2018) Cytoplasmic Mechanisms of Recognition and Defense of Microbial Nucleic Acids. Annu Rev Cell Dev Biol 34:357–379

DOI

15
Hu MM, Shu HB (2019) Innate immune response to cytoplasmic DNA: mechanisms and diseases. Annu Rev Immunol

DOI

16
Hu MM, Yang Q, Xie XQ, Liao CY, Lin H, Liu TT, Yin L, Shu HB (2016) Sumoylation promotes the stability of the DNA sensor cGAS and the adaptor STING to regulate the kinetics of response to DNA virus. Immunity 45:555–569

DOI

17
Hu MM, He WR, Gao P, Yang Q, He K, Cao LB, Li S, Feng YQ, Shu HB (2019) Virus-induced accumulation of intracellular bile acids activates the TGR5-beta-arrestin-SRC axis to enable innate antiviral immunity. Cell Res 29:193–205

DOI

18
Ishikawa H, Barber GN (2008) STING is an endoplasmic reticulum adaptor that facilitates innate immune signalling. Nature 455:674–678

DOI

19
Janeway CA Jr, Medzhitov R (2002) Innate immune recognition. Annu Rev Immunol 20:197–216

DOI

20
Kajino T, Ren H, Iemura S, Natsume T, Stefansson B, Brautigan DL, Matsumoto K, Ninomiya-Tsuji J (2006) Protein phosphatase 6 down-regulates TAK1 kinase activation in the IL-1 signaling pathway. J Biol Chem 281:39891–39896

DOI

21
Li X, Shu C, Yi G, Chaton CT, Shelton CL, Diao J, Zuo X, Kao CC, Herr AB, Li P (2013) Cyclic GMP-AMP synthase is activated by double-stranded DNA-induced oligomerization. Immunity 39:1019–1031

DOI

22
Liu Y, Jesus AA, Marrero B, Yang D, Ramsey SE, Sanchez GAM, Tenbrock K, Wittkowski H, Jones OY, Kuehn HS (2014) Activated STING in a vascular and pulmonary syndrome. N Engl J Med 371:507–518

DOI

23
Liu S, Cai X, Wu J, Cong Q, Chen X, Li T, Du F, Ren J. Wu YT, Grishin NV (2015) Phosphorylation of innate immune adaptor proteins MAVS, STING, and TRIF induces IRF3 activation. Science 347, aaa2630.

DOI

24
Liu H, Zhang H, Wu X, Ma D, Wu J, Wang L, Jiang Y, Fei Y, Zhu C, Tan R (2018) Nuclear cGAS suppresses DNA repair and promotes tumorigenesis. Nature 563:131–136

DOI

25
Long L, Deng Y, Yao F, Guan D, Feng Y, Jiang H, Li X, Hu P, Lu X, Wang H (2014) Recruitment of phosphatase PP2A by RACK1 adaptor protein deactivates transcription factor IRF3 and limits type I interferon signaling. Immunity 40:515–529

DOI

26
Luo WW, Shu HB (2018) Delicate regulation of the cGAS-MITAmediated innate immune response. Cell Mol Immunol 15:666–675

DOI

27
Mackenzie KJ, Carroll P, Martin CA, Murina O, Fluteau A, Simpson DJ, Olova N, Sutcliffe H, Rainger JK, Leitch A (2017) cGAS surveillance of micronuclei links genome instability to innate immunity. Nature 548:461–465

DOI

28
Ogoh H, Tanuma N, Matsui Y, Hayakawa N, Inagaki A, Sumiyoshi M, Momoi Y, Kishimoto A, Suzuki M, Sasaki N (2016) The protein phosphatase 6 catalytic subunit (Ppp6c) is indispensable for proper post-implantation embryogenesis. Mech Dev 139:1–9

DOI

29
Pirman NL, Barber KW, Aerni HR, Ma NJ, Haimovich AD, Rogulina S, Isaacs FJ, Rinehart J (2015) A flexible codon in genomically recoded Escherichia coli permits programmable protein phosphorylation. Nat Commun 6:8130

DOI

30
Shang J. Xia T, Han QQ, Zhao X, Hu MM, Shu HB, Guo L (2018) Quantitative proteomics identified TTC4 as a TBK1 interactor and a positive regulator of SeV-induced innate immunity. Proteomics 18:1

DOI

31
Sun L, Wu J, Du F, Chen X, Chen ZJ (2013) Cyclic GMP-AMP synthase is a cytosolic DNA sensor that activates the type I interferon pathway. Science 339:786–791

DOI

32
Sun W, Li Y, Chen L, Chen H, You F, Zhou X, Zhou Y, Zhai Z, Chen D, Jiang Z (2009) ERIS, an endoplasmic reticulum IFN stimulator,activates innate immune signaling through dimerization. ProcNatl Acad Sci USA 106:8653–8658

DOI

33
West AP, Khoury-Hanold W, Staron M, Tal MC, Pineda CM, Lang SM, Bestwick M, Duguay BA, Raimundo N, MacDuff DA (2015) Mitochondrial DNA stress primes the antiviral innate immune response. Nature 520:553–557

DOI

34
Wies E, Wang MK, Maharaj NP, Chen K, Zhou S, Finberg RW, Gack MU (2013) Dephosphorylation of the RNA sensors RIG-I and MDA5 by the phosphatase PP1 is essential for innate immune signaling. Immunity 38:437–449

DOI

35
Willard FS, Kimple AJ, Johnston CA, Siderovski DP (2005) A direct fluorescence-based assay for RGS domain GTPase accelerating activity. Anal Biochem 340:341–351

DOI

36
Wu J, Sun L, Chen X, Du F, Shi H, Chen C, Chen ZJ (2013) Cyclic GMP-AMP is an endogenous second messenger in innate immune signaling by cytosolic DNA. Science 339:826–830

DOI

37
Xia P, Wang S, Gao P, Gao G, Fan Z (2016) DNA sensor cGASmediated immune recognition. Protein Cell 7:777–791

DOI

38
Xia T, Yi XM, Wu X, Shang J, Shu HB (2019) PTPN1/2-mediated dephosphorylation of MITA/STING promotes its 20S proteasomal degradation and attenuates innate antiviral response. Proc Natl Acad Sci USA 116:20063–20069

DOI

39
Xiong M, Wang S, Wang YY, Ran Y (2018) The regulation of cGAS. Virol Sin 33:117–124

DOI

40
Yan BR, Zhou L, Hu MM, Li M, Lin H, Yang Y, Wang YY, Shu HB (2017) PKACs attenuate innate antiviral response by phosphorylating VISA and priming it for MARCH5-mediated degradation. PLoS Pathog 13:e1006648

DOI

41
Zhan Z, Cao H, Xie X, Yang L, Zhang P, Chen Y, Fan H, Liu Z, Liu X (2015) Phosphatase PP4 negatively regulates type I IFN production and antiviral innate immunity by dephosphorylating and deactivating TBK1. J Immunol 195:3849–3857

DOI

42
Zhong B, Yang Y, Li S, Wang YY, Li Y, Diao F, Lei C, He X, Zhang L, Tien P (2008) The adaptor protein MITA links virus-sensing receptors to IRF3 transcription factor activation. Immunity 29:538–550

DOI

43
Zhong J, Liao J, Liu X, Wang P, Liu J, Hou W, Zhu B, Yao L, Wang J, Li J (2011) Protein phosphatase PP6 is required for homology-directed repair of DNA double-strand breaks. Cell Cycle 10:1411–1419

DOI

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