title: Lys63-linked polyubiquitination of IRAK-1 is required for interleukin-1 receptor- and toll-like receptor-mediated NF-kappaB activation.
abstract: Stimulation through the interleukin-1 receptor (IL-1R) and some Toll-like receptors (TLRs) induces ubiquitination of TRAF6 and IRAK-1, signaling components required for NF-kappaB and mitogen-activated protein kinase activation. Here we show that although TRAF6 and IRAK-1 acquired Lys63 (K63)-linked polyubiquitin chains upon IL-1 stimulation, only ubiquitinated IRAK-1 bound NEMO, the regulatory subunit of IkappaB kinase (IKK). The sites of IRAK-1 ubiquitination were mapped to Lys134 and Lys180, and arginine substitution of these residues impaired IL-1R/TLR-mediated IRAK-1 ubiquitination, NEMO binding, and NF-kappaB activation. K63-linked ubiquitination of IRAK-1 required enzymatically active TRAF6, indicating that it is the physiologically relevant E3. Thus, K63-linked polyubiquitination of proximal signaling proteins is a common mechanism used by diverse innate immune receptors for recruiting IKK and activating NF-kappaB.
authors.affiliation: Laboratory of Immune Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Dietrich B
authors.initials: DB
authors.lastname: Conze
authors.forename: Chuan-Jin
authors.initials: CJ
authors.lastname: Wu
authors.forename: James A
authors.initials: JA
authors.lastname: Thomas
authors.forename: Allison
authors.initials: A
authors.lastname: Landstrom
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Ashwell
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D006801:Humans; D051550:I-kappa B Kinase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053592:Interleukin-1 Receptor-Associated Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008239:Lysine / Q000737:chemistry; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D017472:Receptors, Interleukin-1 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D048029:TNF Receptor-Associated Factor 6 / Q000235:genetics / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism; D051193:Toll-Like Receptors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D054875:Ubiquitination
chemical_list: D017931:DNA Primers; C491731:IKBKG protein, human; D016328:NF-kappa B; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins; C495345:TLR4 protein, human; D048029:TNF Receptor-Associated Factor 6; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; C507768:IRAK1 protein, human; D053592:Interleukin-1 Receptor-Associated Kinases; D051550:I-kappa B Kinase; D008239:Lysine