Usp15 belongs to a family of deubiquitinating enzymes called the DU subfamily. Within this subfamily are Usp4 and Usp11 because they all contain an N-terminal ''domain present in ubiquitin specific proteases (DUSP) and ubiquitin-like (UBL) domains. Usp15 has been shown to play a role in stabilizing and activating caspase-3 during Paclitaxel-induced apoptosis. Usp15 also deubiquitinates IkappaBalpha which is an inhibitor of NF-kappaB.
