Plays a role in the formation of clathrin-coated invaginations and endocytosis. Binds AP-2 and clathrin (By similarity). Interacts with ITSN1 (By similarity). Interacts with UBQLN2 (By similarity). Binds EPS15. In punctate structures throughout the cell and particularly concentrated in the region of the Golgi complex. Highly expressed in brain. Detected at lower levels in lung, liver, muscle and testis. The NPF repeat domain is involved in EPS15 binding. The DPW repeat domain is involved in AP-2 and clathrin binding. Ubiquitinated. Belongs to the epsin family.