OTULIN antagonizes LUBAC signaling by specifically hydrolyzing Met1-linked polyubiquitin

TY - JOUR

T1 - OTULIN antagonizes LUBAC signaling by specifically hydrolyzing Met1-linked polyubiquitin

AU - Keusekotten, Kirstin

AU - Elliott, Paul Ronald

AU - Glockner, Laura

AU - Fiil, Berthe Katrine

AU - Damgaard, Rune Busk

AU - Kulathu, Yogesh

AU - Wauer, Tobias

AU - Hospenthal, Manuela Kathrin

AU - Gyrd-Hansen, Mads

AU - Krappmann, Daniel

AU - Hofmann, Kay

AU - Komander, David

N1 - Copyright © 2013 Elsevier Inc. All rights reserved.

PY - 2013/6/6

Y1 - 2013/6/6

N2 - The linear ubiquitin (Ub) chain assembly complex (LUBAC) is an E3 ligase that specifically assembles Met1-linked (also known as linear) Ub chains that regulate nuclear factor ?B (NF-?B) signaling. Deubiquitinases (DUBs) are key regulators of Ub signaling, but a dedicated DUB for Met1 linkages has not been identified. Here, we reveal a previously unannotated human DUB, OTULIN (also known as FAM105B), which is exquisitely specific for Met1 linkages. Crystal structures of the OTULIN catalytic domain in complex with diubiquitin reveal Met1-specific Ub-binding sites and a mechanism of substrate-assisted catalysis in which the proximal Ub activates the catalytic triad of the protease. Mutation of Ub Glu16 inhibits OTULIN activity by reducing kcat 240-fold. OTULIN overexpression or knockdown affects NF-?B responses to LUBAC, TNFa, and poly(I:C) and sensitizes cells to TNFa-induced cell death. We show that OTULIN binds LUBAC and that overexpression of OTULIN prevents TNFa-induced NEMO association with ubiquitinated RIPK1. Our data suggest that OTULIN regulates Met1-polyUb signaling.

AB - The linear ubiquitin (Ub) chain assembly complex (LUBAC) is an E3 ligase that specifically assembles Met1-linked (also known as linear) Ub chains that regulate nuclear factor ?B (NF-?B) signaling. Deubiquitinases (DUBs) are key regulators of Ub signaling, but a dedicated DUB for Met1 linkages has not been identified. Here, we reveal a previously unannotated human DUB, OTULIN (also known as FAM105B), which is exquisitely specific for Met1 linkages. Crystal structures of the OTULIN catalytic domain in complex with diubiquitin reveal Met1-specific Ub-binding sites and a mechanism of substrate-assisted catalysis in which the proximal Ub activates the catalytic triad of the protease. Mutation of Ub Glu16 inhibits OTULIN activity by reducing kcat 240-fold. OTULIN overexpression or knockdown affects NF-?B responses to LUBAC, TNFa, and poly(I:C) and sensitizes cells to TNFa-induced cell death. We show that OTULIN binds LUBAC and that overexpression of OTULIN prevents TNFa-induced NEMO association with ubiquitinated RIPK1. Our data suggest that OTULIN regulates Met1-polyUb signaling.

KW - Animals

KW - Models, Molecular

KW - Humans

KW - Polyubiquitin

KW - Amino Acid Sequence

KW - Endopeptidases

KW - Sequence Alignment

KW - Molecular Sequence Data

KW - Cytokines

KW - Crystallography, X-Ray

KW - Protein Structure, Tertiary

KW - Signal Transduction

KW - Catalysis

U2 - 10.1016/j.cell.2013.05.014

DO - 10.1016/j.cell.2013.05.014

M3 - Article

C2 - 23746843

SN - 1097-4172

VL - 153

SP - 1312

EP - 1326

JO - Cell

JF - Cell

IS - 6

ER -