OTUD5 (Deubiquitinating enzyme A (DUBA)) is a negative regulator of type I interferon (IFN-) production. TRAF3, an E3 ubiquitin ligase that preferentially assembles lysine-63-linked polyubiquitin chains, is one of the targets of OTUD5. Expression of DUBA increases the cleavage of K63-linked ubiquitin chains from TRAF3, resulting in its dissociation from the downstream signaling complex that contains TANK-binding kinase 1 (TBK1) (Kayagaki et al. 2007), which leads to blockade of IRF3 and IRF7 phosphorylation.
Lys63-specific deubiquitinase activity of OTUD5 [cytosol]