May participate in mechanisms of regulated exocytosis in synapses and certain endocrine cell types. May control the properties of the membrane associated cytoskeleton (By similarity). Heterodimer with BIN1 (PubMed:9341169). Binds SH3GLB1 (By similarity). Interacts with REPS1 and SGIP1 (By similarity). Binds AP2A2 (PubMed:10380931, PubMed:10430869). Interacts with AP2B1 (PubMed:16516836, PubMed:16903783). Interacts with DNM1 AND SYNJ1 (PubMed:9341169).