Deubiquitinase

Deubiquitinases (DUBs) are a family of proteases whose function is to cleave ubiquitin (Ub) or ubiquitin-like proteins from proproteins or ubiquitin(s) conjugated with target substrate. DUBs are divided into two main classes according to their enzymatic cleavage mechanism: cysteine proteases and zinc metalloproteases. These include ubiquitin-specific proteases (USPs), ubiquitin C-terminal hydrolases (UCHs), ovarian tumor proteases (OTUs), Machado-Joseph disease proteases (MJDs), Jab1/Mov34/Mpr1 (JAMM) metalloproteases, and MIU-containing novel DUB family, (MINDY) proteases.

Ubiquitination is an important post-translational modification that plays a key role in many vital cellular events. In this process, ubiquitin is attached to a substrate protein by the concerted action of an enzyme cascade involving E1, E2 and E3 enzymes and it is removed by DUBs. DUBs are therefore important regulators of the Ub system and regulate a plethora of cellular processes, including protein turnover, protein sorting, and trafficking. Altered DUB activity is associated with a multitude of pathologies including cancer. DUBs represent novel candidates for target-directed drug development.