OTULIN Antibody #14127

Protein ubiquitination and deubiquitination are reversible processes catalyzed by ubiquitinating enzymes (UBEs) and deubiquitinating enzymes (DUBs) (1,2). Five subfamilies of DUBs have been characterized to date, and include USP, UCH, OTU, MJD, and JAMM deubiquitinating enzymes (1,2). The ovarian tumor (OTU) DUB subfamily comprises a group of approximately 100 putative cysteine proteases that are homologous to the Drosophila ovarian tumor gene product (3). OTU domain-containing deubiquitinase with linear linkage specificity (OTULIN, FAM105B, Gumby) is an OTU subfamily deubiquitinating enzyme that antagonizes the E3 linear ubiquitin chain assembly complex (LUBAC) by promoting disassembly of Met1-linked (linear) ubiquitin chains (4,5). LUBAC and OTULIN regulate NOD2 signaling in an antagonistic manner by controlling the level of Met1-ubiquitinated RIPK2 kinase (6). Binding of the OTULIN PUB-interacting motif to the HOIP subunit of LUBAC is critical for OTULIN inhibition of NF-κΒ signaling; this OTULIN-HOIP interaction is negatively regulated by tyrosine phosphorylation of OTULIN (7,8). The ability of OTULIN to influence LUBAC function and the presence of linear ubiquitin chains may play an important role in regulating angiogenesis, craniofacial, and neural development (5).