Amphiphysin, isoform 1 (IPR003017)

Short name: Amphiphysin_1

Overlapping homologous superfamilies


Family relationships

  • Amphiphysin (IPR003005)
    • Amphiphysin, isoform 1 (IPR003017)


Amphiphysins belong to the expanding BAR (Bin-Amphiphysin-Rvsp) family proteins, all members of which share a highly conserved N-terminal BAR domain, which has predicted coiled-coil structures required for amphiphysin dimerisation and plasma membrane interaction [PMID: 12047553]. Almost all members also share a conserved C-terminal Src homology 3 (SH3) domain, which mediates their interactions with the GTPase dynamin and the inositol-5'-phosphatase synaptojanin 1 in vertebrates and with actin in yeast. The central region of all these proteins is most variable. In mammals, the central region of amphiphysin I and amphiphysin IIa contains a proline-arginine-rich region for endophilin binding and a CLAP domain, for binding to clathrin and AP-2. The interactions mediated by both the central and C-terminal domains are believed to be modulated by protein phosphorylation [PMID: 9720601, PMID: 10559861].

Amphiphysins are proteins that are thought to be involved in clathrin-mediated endocytosis, actin function, and signalling pathways [PMID: 12047553]. In vertebrates, amphiphysins may regulate, but are not essential for clathrin-mediated endocytosis of SVs. However, in Drosophila amphiphysin is not involved at all in SV endocytosis but is required for T-tubule structure and excitation-contraction coupling muscles and plays a role in membrane morphogenesis in developing photoreceptors and a variety of other cells.

Amphiphysin 1 was first identified in 1992 as a brain protein that was partially-associated with synaptic vesicles. Following its cloning, it was also realised to be a human auto-antigen that is detected in a rar neurological disease, Stiff-Man Syndrome, and also in certain types of cancer [PMID: 10025422].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.