Deubiquitinating enzyme exhibiting a preference towards 'Lys-63'-linked ubiquitin chains. 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). Highly expressed in skeletal muscle. Expressed in adrenal gland. Belongs to the peptidase C19 family. The absence of the residues from Tyr-840 to Ser-871 is not the result of an alternative splicing.