OTUD1 deubiquitylase regulates NF-κB- and KEAP1-mediated inflammatory responses and reactive oxygen species-associated cell death pathways
Deubiquitylating enzymes (DUBs) regulate numerous cellular functions by removing ubiquitin modifications. We examined the effects of 88 human DUBs on linear ubiquitin chain assembly complex (LUBAC)-induced NF-{kappa}B activation, and identified OTUD1 as a potent suppressor. OTUD1 regulates the canonical NF-{kappa}B pathway by hydrolysing K63-linked ubiquitin chains from NF-{kappa}B signalling factors, including LUBAC. OTUD1 negatively regulates the canonical NF-{kappa}B activation, apoptosis, and necroptosis, whereas OTUD1 upregulates the interferon (IFN) antiviral pathway. The N-terminal intrinsically disordered region of OTUD1, which contains an EGTE motif, is indispensable for KEAP1-binding and NF-{kappa}B suppression. OTUD1 is involved in the KEAP1-mediated antioxidant response and reactive oxygen species (ROS)-induced cell death, oxeiptosis. In Otud1-/--mice, inflammation, oxidative damage, and cell death were enhanced in inflammatory bowel disease, acute hepatitis, and sepsis models. Thus, OTUD1 is a crucial regulator for the inflammatory, innate immune, and oxidative stress responses and ROS-associated cell death pathways.