Deubiquitinates monoubiquitinated probes (in vitro). When ubiquitinated, cleaves 'Lys-63'-linked and 'Lys-48'-linked poly-ubiquitin chains (in vitro), hence may act as a deubiquitinating enzyme. May increase macropinocytosis and suppress clathrin- and caveolae-mediated endocytosis. May enhance membrane dynamics and cell motility independently of its catalytic activity (By similarity). 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). Interacts with beta-actin/ACTB. Ubiquitination increases localization the plasma membrane. In the cytosol, the unubiquitinated form may be associated with the cytoskeleton via ACTB-binding. Widely expressed (at protein level). Monoubiquitinated. Ubiquitination activates deubiquitination activity in vitro.