Description
There are two main classes of DUB, cysteine proteases and metalloproteases. Ubiquitin specific protease 1 (USP1) is a member of the cysteine protease enzyme family and cloning of the human gene was first described by Fujiwara et al. (1998). USP1 has been shown to act as a negative regulator of the Fanconi anaemia pathway. Inhibition of USP1 by siRNA knockdown increased the monoubiquitylation of the Fanconi anaemia effector protein, FANCD2, and increased cellular resistance to DNA cross-linking agents, suggesting that USP1 deubiquitylates FANCD2 (Huang et al., 2006)