Enables thiol-dependent deubiquitinase. Acts upstream of or within protein deubiquitination. Predicted to be located in endoplasmic reticulum membrane. Predicted to be active in cytosol and nucleus. Orthologous to several human genes including USP17L1 (ubiquitin specific peptidase 17 like family member 1); USP17L2 (ubiquitin specific peptidase 17 like family member 2); and USP17L3 (ubiquitin specific peptidase 17 like family member 3). [provided by Alliance of Genome Resources, Apr 2022]