title: Pyk2 activates the NLRP3 inflammasome by directly phosphorylating ASC and contributes to inflammasome-dependent peritonitis.
abstract: The inflammasome adaptor protein, ASC, contributes to both innate immune responses and inflammatory diseases via self-oligomerization, which leads to the activation of the protease, caspase-1. Here, we report that the cytosolic tyrosine kinases, FAK and Pyk2, are differentially involved in NLRP3 and AIM2 inflammasome activation. The inhibition of FAK and Pyk2 with RNA interference or chemical inhibitors dramatically abolished ASC oligomerization, caspase-1 activation, and IL-1β secretion in response to NLRP3 or AIM2 stimulation. Pyk2 is phosphorylated by the kinase Syk and relocalizes to the ASC specks upon NLRP3 inflammasome activation. Pyk2, but not FAK, could directly phosphorylate ASC at Tyr146, and only the phosphorylated ASC could participate in speck formation and trigger IL-1β secretion. Moreover, the clinical-trial-tested Pyk2/FAK dual inhibitor PF-562271 reduced monosodium urate-mediated peritonitis, a disease model used for studying the consequences of NLRP3 activation. Our results suggest that although Pyk2 and FAK are involved in inflammasome activation, only Pyk2 directly phosphorylates ASC and brings ASC into an oligomerization-competent state by allowing Tyr146 phosphorylation to participate ASC speck formation and subsequent NLRP3 inflammation.
authors: Molecular Medicine Research Center, Chang Gung University, 333 Taoyuan, Taiwan.
authors: I-Che
authors: IC
authors: Chung
authors: Molecular Medicine Research Center, Chang Gung University, 333 Taoyuan, Taiwan.
authors: Chun-Nan
authors: CN
authors: OuYang
authors: Molecular Medicine Research Center, Chang Gung University, 333 Taoyuan, Taiwan.
authors: Sheng-Ning
authors: SN
authors: Yuan
authors: Department of Microbiology and Immunology, Chang Gung University, 333 Taoyuan, Taiwan.|Graduate Institute of Biomedical Sciences, Chang Gung University, 333 Taoyuan, Taiwan.|Division of Hematology-Oncology, Chang Gung Memorial Hospital at Lin-Kuo, 333 Taoyuan, Taiwan.
authors: Hsin-Pai
authors: HP
authors: Li
authors: Molecular Medicine Research Center, Chang Gung University, 333 Taoyuan, Taiwan.
authors: Jeng-Ting
authors: JT
authors: Chen
authors: Department of Medical Research Mackay Memorial Hospital, 251 New Taipei City, Taiwan.
authors: Hui-Ru
authors: HR
authors: Shieh
authors: Department of Medical Research Mackay Memorial Hospital, 251 New Taipei City, Taiwan.|Department of Radiation Oncology, Mackay Memorial Hospital, 251 New Taipei City, Taiwan.
authors: Yu-Jen
authors: YJ
authors: Chen
authors: Department of Biomedical Sciences, University of the Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA 94103, USA.
authors: David M
authors: DM
authors: Ojcius
authors: Graduate Institute of Immunology, College of Medicine, National Taiwan University, 100 Taipei, Taiwan.
authors: Ching-Liang
authors: CL
authors: Chu
authors: Graduate Institute of Biomedical Sciences, Chang Gung University, 333 Taoyuan, Taiwan.|Proteomics Core Laboratory, Chang Gung University, 333 Taoyuan, Taiwan.|Liver Research Center, Chang Gung Memorial Hospital at Lin-Kou, 333 Taoyuan, Taiwan.
authors: Jau-Song
authors: JS
authors: Yu
authors: Molecular Medicine Research Center, Chang Gung University, 333 Taoyuan, Taiwan.|Graduate Institute of Biomedical Sciences, Chang Gung University, 333 Taoyuan, Taiwan.|Department of Otolaryngology, Chang Gung Memorial Hospital at Lin-Kuo, 333 Taoyuan, Taiwan.
authors: Yu-Sun
authors: YS
authors: Chang
authors: Department of Medicine, Mackay Medical College, 252 New Taipei City, Taiwan.
authors: Lih-Chyang
authors: LC
authors: Chen
mesh_terms: D000818:Animals; D053468:CARD Signaling Adaptor Proteins / Q000235:genetics / Q000276:immunology*; D051418:Focal Adhesion Kinase 2 / Q000235:genetics / Q000276:immunology*; D058847:Inflammasomes / Q000235:genetics / Q000276:immunology*; D007249:Inflammation / Q000139:chemically induced / Q000235:genetics / Q000276:immunology / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein / Q000235:genetics / Q000276:immunology*; D010538:Peritonitis / Q000139:chemically induced / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D010766:Phosphorylation / Q000235:genetics / Q000276:immunology; D055503:Protein Multimerization / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D014527:Uric Acid / Q000633:toxicity
chemical_list: D053468:CARD Signaling Adaptor Proteins; D058847:Inflammasomes; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C492716:Nlrp3 protein, mouse; C498534:Pycard protein, mouse; D014527:Uric Acid; D051418:Focal Adhesion Kinase 2; C496053:Ptk2b protein, mouse