Ubiquitin Specific Peptidase 7 (USP7)

HAUSP is a ubiquitin specific protease or a deubiquitylating enzyme that cleaves ubiquitin from its substrates.Since ubiquitylation (polyubiquitination) is most commonly associated with the stability and degradation of cellular proteins, HAUSP acitivity generally stabilizes its substrate proteins. HAUSP is most popularly known as a direct antagonist of Mdm2, the E3 ubiquitin ligase for the tumor suppressor protein, p53. Normally, p53 levels are kept low in part due to Mdm2-mediated ubiquitylation and degradation of p53. Interestingly, in response to oncogenic insults, HAUSP can deubiquitinate p53 and protect p53 from Mdm2-mediated degradation, indicating that it may possess a tumor suppressor function for the immediate stabilization of p53 in response to stress.