Predicted to enable endopeptidase inhibitor activity; proteasome binding activity; and thiol-dependent deubiquitinase. Predicted to be involved in several processes, including brain development; negative regulation of proteasomal ubiquitin-dependent protein catabolic process; and positive regulation of smoothened signaling pathway. Part of cytosolic proteasome complex. Orthologous to human UCHL5 (ubiquitin C-terminal hydrolase L5). [provided by Alliance of Genome Resources, Apr 2022]