USP53
Inactive ubiquitin carboxyl-terminal hydrolase 53 is a protein that in humans is encoded by the USP53 gene.
Although USP53 is classified as a deubiquitinating enzyme based on sequence homology to other proteases from this group, it lacks a functionally essential histydine in the catalytic domaine and activity assays suggest that USP53 is catalytically inactive.
Even though USP53 is devoid of catalytic activity, USP53 serves important physiological functions:
mutations in Usp53 have been shown to cause progressive hearing loss in mice, as well as late-onset hearing loss and cholestasis in humans.
USP53 localizes at cellular tight junctions and interacts with tight junction protein 2. Mutations in TJP2 have also been shown to cause hearing impairments and cholestasis.
