OTU domain-containing protein 4 (OTUD4)

Deubiquitinase which hydrolyzes the isopeptide bond between the ubiquitin C-terminus and the lysine epsilon-amino group of the target protein (PubMed:23827681, PubMed:25944111, PubMed:29395066). May negatively modulate inflammatory and pathogen recognition signaling in innate immune reaction.

Upon phosphorylation in Ser-202 and Ser-204 residues, through IL-1 receptor and Toll-like receptor signaling pathway, specifically deubiquitinates'Lys-63'-polyubiquitinated MYD88 adapter protein triggering down-regulation of NF-kappa-B-dependent transcription of inflammatory mediators (PubMed:29395066). Independently of the catalytic activity, acts as a scaffold for alternative deubiquitinases to assemble specific deubiquitinase-substrate complexes.