| Type: | Domain | Name: | Arfaptin homology (AH) domain/BAR domain |
| Description: | This entry represents a domain consists of three alpha-helices, including the arfaptin homology (AH) domain and the BAR (Bin-Amphiphysin-Rvs)-domain. The arfaptin homology (AH) domain is a protein domain found in a range of proteins, including arfaptins, protein kinase C-binding protein PICK1 [] and mammalian 69 kDa islet cell autoantigen (ICA69) []. The AH domain of arfaptin has been shown to dimerise and to bind Arf and Rho family GTPases [, ], including ARF1, a small GTPase involved in vesicle budding at the Golgi complex and immature secretory granules. The AH domain consists of three alpha-helices arranged as an extended antiparallel alpha-helical bundle. Two arfaptin AH domains associate to form a highly elongated, crescent-shaped dimer [, ].Members of the Amphiphysin protein family are key regulators in the early steps of endocytosis, involved in the formation of clathrin-coated vesicles by promoting the assembly of a protein complex at the plasma membrane and directly assist in the induction of the high curvature of the membrane at the neck of the vesicle. Amphiphysins contain a characteristic domain, known as the BAR (Bin-Amphiphysin-Rvs)-domain, which is required for their in vivofunction and their ability to tubulate membranes []. The crystal structure of these proteins suggest the domain forms a crescent-shaped dimer of a three-helix coiled coil with a characteristic set of conserved hydrophobic, aromatic and hydrophilic amino acids. Proteins containing this domain have been shown to homodimerise, heterodimerise or, in a few cases, interact with small GTPases. | Short Name: | AH/BAR-dom |
