title: Activation of the canonical IKK complex by K63/M1-linked hybrid ubiquitin chains.
abstract: Polyubiquitin (pUb) chains formed between the C terminus of ubiquitin and lysine 63 (K63) or methionine 1 (M1) of another ubiquitin have been implicated in the activation of the canonical IκB kinase (IKK) complex. Here, we demonstrate that nearly all of the M1-pUb chains formed in response to interleukin-1, or the Toll-Like Receptors 1/2 agonist Pam3CSK4, are covalently attached to K63-pUb chains either directly as K63-pUb/M1-pUb hybrids or indirectly by attachment to the same protein. Interleukin-1 receptor (IL-1R)-associated kinase (IRAK) 1 is modified first by K63-pUb chains to which M1-pUb linkages are added subsequently, and myeloid differentiation primary response gene 88 (MyD88) and IRAK4 are also modified by both K63-pUb and M1-pUb chains. We show that the heme-oxidized IRP2 ubiquitin ligase 1 interacting protein (HOIP) component of the linear ubiquitin assembly complex catalyzes the formation of M1-pUb chains in response to interleukin-1, that the formation of K63-pUb chains is a prerequisite for the formation of M1-pUb chains, and that HOIP interacts with K63-pUb but not M1-pUb linkages. These findings identify K63-Ub oligomers as a major substrate of HOIP in cells where the MyD88-dependent signaling network is activated. The TGF-beta-activated kinase 1 (TAK1)-binding protein (TAB) 2 and TAB3 components of the TAK1 complex and the NFκB Essential Modifier (NEMO) component of the canonical IKK complex bind to K63-pUb chains and M1-pUb chains, respectively. The formation of K63/M1-pUb hybrids may therefore provide an elegant mechanism for colocalizing both complexes to the same pUb chain, facilitating the TAK1-catalyzed activation of IKKα and IKKβ. Our study may help to resolve the debate about the relative importance of K63-pUb and M1-pUb chains in activating the canonical IKK complex.
authors.affiliation: Medical Research Council Protein Phosphorylation and Ubiquitylation Unit and Division of Cell Signaling and Immunology, Sir James Black Centre, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom.
authors.forename: Christoph H
authors.initials: CH
authors.lastname: Emmerich
authors.forename: Alban
authors.initials: A
authors.lastname: Ordureau
authors.forename: Sam
authors.initials: S
authors.lastname: Strickson
authors.forename: J Simon C
authors.initials: JS
authors.lastname: Arthur
authors.forename: Patrick G A
authors.initials: PG
authors.lastname: Pedrioli
authors.forename: David
authors.initials: D
authors.lastname: Komander
authors.forename: Philip
authors.initials: P
authors.lastname: Cohen
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli; D005347:Fibroblasts; D055879:Gene Knock-In Techniques; D057809:HEK293 Cells; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism*; D007113:Immunity, Innate / Q000276:immunology*; D015151:Immunoblotting; D047468:Immunoprecipitation; D007375:Interleukin-1 / Q000276:immunology; D053592:Interleukin-1 Receptor-Associated Kinases / Q000378:metabolism; D008239:Lysine / Q000378:metabolism; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D013058:Mass Spectrometry; D008715:Methionine / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D046912:Multiprotein Complexes / Q000276:immunology* / Q000378:metabolism; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D025821:Polyubiquitin / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D012394:Rosaniline Dyes; D015398:Signal Transduction / Q000276:immunology*; D044767:Ubiquitin-Protein Ligases; D000099151:MAP Kinase Kinase Kinase 7
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D051550:I-kappa B Kinase; D007375:Interleukin-1; D053592:Interleukin-1 Receptor-Associated Kinases; D008239:Lysine; D020930:MAP Kinase Kinase Kinases; D008715:Methionine; D046912:Multiprotein Complexes; D053594:Myeloid Differentiation Factor 88; D025821:Polyubiquitin; D034741:RNA, Small Interfering; D012394:Rosaniline Dyes; D044767:Ubiquitin-Protein Ligases; D000099151:MAP Kinase Kinase Kinase 7; C491731:IKBKG protein, human; C048139:Coomassie blue; C558338:RNF31 protein, human; C507773:IRAK4 protein, human
keywords: LUBAC; NF-κB; TNF Receptor-Associated Factor 6; Ubc13