Ubiquitin C-terminal hydrolases (UCHs) are a family of cysteine hydrolases that catalyze the hydrolysis of amides, esters and thioesters of the C-terminus of ubiquitin. UCH-L3 is a member of the lower molecular weight group of UCHs involved in the hydrolysis of small C-terminal derivatives of ubiquitin that form non-specifically during the process of protein ubiquitinylation. UCHL3 play a role in the regulation of neuronal development and spermatogenesis and have been implicated in neurodegenerative diseases.