May have a role in transport via clathrin-coated vesicles from the trans-Golgi network to endosomes. Stimulates clathrin assembly (By similarity). Does not seem to bind to phospholipids. Plays an important role in the vacuolar trafficking of soluble cargo proteins at the trans-Golgi network. Interacts with clathrin, VTI11, GAMMA-ADR and VSR1. Binds to the deubiquitinating enzyme AMSH3. Associated with actin filaments. Mostly expressed in cotyledons and flowers, and, to a lower extent, in roots, leaves and siliques (at protein level). Defect in vacuolar trafficking. Belongs to the epsin family.