Reference - Detail
|Author||Tanishima M, Takashima S, Honda A, Yasuda D, Tanikawa T, Ishii S, MaruYama T.|
|Title||Identification of optineurin as an interleukin-1 receptor-associated kinase 1-binding protein and its role in regulation of MyD88-dependent signaling.|
|Journal||J Biol Chem|
Upon stimulation of toll-like receptors with various microbial ligands, induction of a variety of inflammatory genes is elicited by activation of a myeloid differentiation primary-response protein 88 (MyD88)-dependent signaling pathway. Interleukin-1 (IL-1) receptor-associated kinase 1 (IRAK1) plays an essential role in this pathway by activating nuclear factor κB (NF-κB) and mitogen-activated kinases (MAPKs). Here, we identified optineurin (OPTN) as an IRAK1-binding protein by yeast two-hybrid screening using IRAK1 as bait. A C-terminal fragment of OPTN harboring a ubiquitin-binding domain was co-immunoprecipitated with IRAK1. In reporter analyses, overexpression of OPTN inhibited IL-1β-, IRAK1-, and LPS-induced NF-κB activation. Consistently, OPTN deficiency resulted in increased NF-κB activation in response to IL-1β/LPS stimulation. To address the mechanisms underlying the inhibitory effect of OPTN on NF-κB signaling, we focused on tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6), which is an adaptor protein of IRAK1 and upon polyubiquitination plays a crucial role during NF-κB activation. Overexpression of OPTN prevented TRAF6 polyubiquitination. Furthermore, OPTN H486R mutant, which is unable to recruit the deubiquitinase CYLD, failed to inhibit IRAK1-induced NF-κB activation. These results suggest that the IRAK1-binding protein OPTN negatively regulates IL-1β/LPS-induced NF-κB activation by preventing polyubiquitination of TRAF6.
|MeSH||Amino Acid Substitution Animals Cysteine Endopeptidases / genetics Cysteine Endopeptidases / metabolism Deubiquitinating Enzyme CYLD Eye Proteins / genetics Eye Proteins / metabolism* HEK293 Cells Humans Interleukin-1 Receptor-Associated Kinases / genetics Interleukin-1 Receptor-Associated Kinases / metabolism* Lipopolysaccharides / pharmacology Mice Mutation, Missense Myeloid Differentiation Factor 88 / genetics Myeloid Differentiation Factor 88 / metabolism* NF-kappa B / genetics NF-kappa B / metabolism RAW 264.7 Cells Signal Transduction / drug effects Signal Transduction / physiology* TNF Receptor-Associated Factor 6 / genetics TNF Receptor-Associated Factor 6 / metabolism Transcription Factor TFIIIA / genetics Transcription Factor TFIIIA / metabolism* Tumor Suppressor Proteins / genetics Tumor Suppressor Proteins / metabolism Ubiquitination / drug effects Ubiquitination / physiology|
|DNA material||pEF6-FLAG-human IRAK1 (RDB16723) pCDNA3-FLAG-human TRAF6 (RDB16722) pEF6-Myc-mouse Optineurin (RDB16718) pEF6-Myc-mouse Optineurin(E50K) (RDB16719) pEF6-Myc-mouse Optineurin(D474N) (RDB16720) pEF6-Myc-mouse Optineurin(H486R) (RDB16721)|