Tags: Protein.
Ubiquitin specific protease 4 (USP4) is an enzyme that cleaves ubiquitin from a number of protein substrates. Prior to the standardization of nomenclature USP4 was known as UNP and was one of the first deubiquitinating enzymes to be identified in mammals. In the mouse and human the USP4 protein is encoded by a gene containing 22 exons.This protein is a member of cysteine peptidase family C19. As a deubiquitinating enzyme it is unusual in having the capacity to cleave ubiquitin-proline bonds.