USP 33 is a deubiquitinating enzyme involved in various processes such as cellular migration and beta-2 adrenergicreceptor/ADRB2 recycling. It is involved in cell migration via its interaction with intracellular domain of ROBO1, leadingto regulation of Slit signaling. It also plays a role in commissural axon guidance cross the ventral midline of the neural tube in a Slit-dependent manner, possibly by mediating the deubiquitination of ROBO1. Acts as a regulator of G-proteincoupled receptor (GPCR) signaling by mediating the deubiquitination of beta-arrestins (ARRB1 and ARRB2) and beta-2adrenergic receptor (ADRB2).