Hydrolase that deubiquitinates polyubiquitinated target proteins such as MDM2, MDM4 and CCND1. Possesses both ubiquitin- specific peptidase and isopeptidase activities. May play a role in the regulation of the circadian clock. {By
SimilarityUniProtKB:O75604, By
SimilarityUniProtKB:O88623}.