Deubiquitinating enzyme. Has almost no deubiquitinating activity by itself and requires the interaction with WDR48 to have a high activity. Not involved in deubiquitination of monoubiquitinated FANCD2. Thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal). Activated by interaction with WDR20 and WDR48 through different allosteric mechanisms. Interacts with WDR48. Interacts with WDR20. Component of the USP12/WDR20/WDR48 deubiquitinating complex. Belongs to the peptidase C19 family. USP12/USP46 subfamily.