title: DOK3 is required for IFN-β production by enabling TRAF3/TBK1 complex formation and IRF3 activation.
abstract: The downstream of kinase (DOK) family of adaptors is generally involved in the negative regulation of signaling pathways. DOK1, 2, and 3 were shown to attenuate TLR4 signaling by inhibiting Ras-ERK activation. In this study, we elucidated a novel role for DOK3 in IFN-β production. Macrophages lacking DOK3 were impaired in IFN-β synthesis upon influenza virus infection or polyinosinic-polyribocytidylic acid stimulation. In the absence of DOK3, the transcription factor IFN regulatory factor 3 was not phosphorylated and could not translocate to the nucleus to activate ifn-β gene expression. Interestingly, polyinosinic-polyribocytidylic acid-induced formation of the upstream TNFR-associated factor (TRAF) 3/TANK-binding kinase (TBK) 1 complex was compromised in dok3(-/-) macrophages. DOK3 was shown to bind TBK1 and was required for its activation. Furthermore, we demonstrated that overexpression of DOK3 and TBK1 could significantly enhance ifn-β promoter activity. DOK3 was also shown to bind TRAF3, and the binding of TRAF3 and TBK1 to DOK3 required the tyrosine-rich C-terminal domain of DOK3. We further revealed that DOK3 was phosphorylated by Bruton's tyrosine kinase. Hence, DOK3 plays a critical and positive role in TLR3 signaling by enabling TRAF3/TBK1 complex formation and facilitating TBK1 and IFN regulatory factor 3 activation and the induction of IFN-β production.
authors.affiliation: Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228; Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668; and.
authors.forename: Susana Soo-Yeon
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668; and.
authors.forename: Koon-Guan
authors.initials: KG
authors.lastname: Lee
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668; and.
authors.forename: Ching-Siang
authors.initials: CS
authors.lastname: Chin
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668; and.
authors.forename: Say-Kong
authors.initials: SK
authors.lastname: Ng
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668; and.
authors.forename: Natasha Ann
authors.initials: NA
authors.lastname: Pereira
authors.affiliation: Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668; and.
authors.forename: Shengli
authors.initials: S
authors.lastname: Xu
authors.affiliation: Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228; Bioprocessing Technology Institute, Agency for Science, Technology and Research, Singapore 138668; and Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228 lam_kong_peng@bti.a-star.edu.sg.
authors.forename: Kong-Peng
authors.initials: KP
authors.lastname: Lam
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D015870:Gene Expression; D057809:HEK293 Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D050838:Interferon Regulatory Factor-3 / Q000235:genetics / Q000378:metabolism*; D016899:Interferon-beta / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000378:metabolism / Q000821:virology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D009975:Orthomyxoviridae / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D011070:Poly I-C / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D048008:TNF Receptor-Associated Factor 3 / Q000235:genetics / Q000378:metabolism*; D051196:Toll-Like Receptor 3 / Q000235:genetics / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C406768:Dok3 protein, mouse; D050838:Interferon Regulatory Factor-3; C494233:Irf3 protein, mouse; C519703:TLR3 protein, mouse; D048008:TNF Receptor-Associated Factor 3; D051196:Toll-Like Receptor 3; D016899:Interferon-beta; C498588:Tbk1 protein, mouse; D017346:Protein Serine-Threonine Kinases; D011070:Poly I-C