Associates with cyclin G and CDK5. Seems to act as an auxilin homolog that is involved in the uncoating of clathrin-coated vesicles by Hsc70 in non-neuronal cells. Expression oscillates slightly during the cell cycle, peaking at G1 (PubMed:10625686). May play a role in clathrin-mediated endocytosis and intracellular trafficking, and in the dynamics of clathrin assembly/disassembly (PubMed:18489706).