title: The K48-K63 Branched Ubiquitin Chain Regulates NF-κB Signaling.
abstract: Polyubiquitin chains of different topologies regulate diverse cellular processes. K48- and K63-linked chains, the two most abundant chain types, regulate proteolytic and signaling pathways, respectively. Although recent studies reported important roles for heterogeneous chains, the functions of branched ubiquitin chains remain unclear. Here, we show that the ubiquitin chain branched at K48 and K63 regulates nuclear factor κB (NF-κB) signaling. A mass-spectrometry-based quantification strategy revealed that K48-K63 branched ubiquitin linkages are abundant in cells. In response to interleukin-1β, the E3 ubiquitin ligase HUWE1 generates K48 branches on K63 chains formed by TRAF6, yielding K48-K63 branched chains. The K48-K63 branched linkage permits recognition by TAB2 but protects K63 linkages from CYLD-mediated deubiquitylation, thereby amplifying NF-κB signals. These results reveal a previously unappreciated cooperation between K48 and K63 linkages that generates a unique coding signal: ubiquitin chain branching differentially controls readout of the ubiquitin code by specific reader and eraser proteins to activate NF-κB signaling.
authors.affiliation: Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Division of Cellular and Molecular Toxicology, Biological Safety Research Center, National Institute of Health Sciences, Tokyo 158-8501, Japan. Electronic address: otake-fm@igakuken.or.jp.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Ohtake
authors.affiliation: Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Saeki
authors.affiliation: Department of Microbiology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ishido
authors.affiliation: Division of Cellular and Molecular Toxicology, Biological Safety Research Center, National Institute of Health Sciences, Tokyo 158-8501, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Kanno
authors.affiliation: Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan. Electronic address: tanaka-kj@igakuken.or.jp.
authors.forename: Keiji
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001665:Binding Sites; D045744:Cell Line, Tumor; D000074749:Deubiquitinating Enzyme CYLD; D015870:Gene Expression; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008239:Lysine / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D016328:NF-kappa B / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D025821:Polyubiquitin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D000072757:Protein Conformation, beta-Strand; D054730:Protein Interaction Domains and Motifs; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction; D013379:Substrate Specificity; D048029:TNF Receptor-Associated Factor 6 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D025801:Ubiquitin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C508585:IL1B protein, human; D053583:Interleukin-1beta; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; D011994:Recombinant Proteins; C410585:TAB2 protein, human; D048029:TNF Receptor-Associated Factor 6; C000604754:Tifab protein, human; D025521:Tumor Suppressor Proteins; D025801:Ubiquitin; D025821:Polyubiquitin; C502830:HUWE1 protein, human; D044767:Ubiquitin-Protein Ligases; C409984:CYLD protein, human; D000074749:Deubiquitinating Enzyme CYLD; D008239:Lysine
keywords: AQUA; CYLD; HUWE1; Lys48; Lys63; NF-κB; TRAF6; inflammation; proteomics