May have a role in transport via clathrin-coated vesicles from the trans-Golgi network to endosomes. Stimulates clathrin assembly (By similarity). Binds to membranes enriched in phosphatidylinositol 3-phosphate (PtdIns(3)P). Plays an important role in protein trafficking. Interacts with clathrin, VTI12, DELTA-ADR and ALPHA-ADR. Localizes also to a novel cellular compartment, the 'delta compartment', characterized by colocalization of EPSIN2 and DELTA-ADR. The ENTH domain is required for PtdIns(3)P affinity and EPSIN2 subcellular location. Belongs to the epsin family.