Amphiphysins, members of the BAR (Bin-Amphiphysin-Rvsp) protein super family, play a key role in clathrinmediated endocytosis of synaptic vesicles (SVs). All members of the BAR family share a highly conserved N-terminal BAR domain and a C-terminal Src homology (SH3) domain. Two isoforms of amphiphysin have been identified and act in concert as a heterodimer. Amphiphysins interact via its carboxy-terminal SH3 domain with dynamin, synaptojanin and clathrin. These complexes are implicated in synaptic vesicle recycling at nerve terminal. Amphiphysins were also identified as the dominant autoantigen in paraneoplastic Stiff-Man Syndrome.