ANTH (AP180 N-Terminal Homology) domain, N-terminal region, of Sla2p and similar proteins
This subfamily is composed of Saccharomyces cerevisiae Sla2 protein (Sla2p, also called transmembrane protein MOP2), Schizosaccharomyces pombe endocytosis protein End4 (End4p, also called Sla2 protein homolog), and similar proteins. In yeast, cells lacking Sla2p have severe defects in actin organization, cell morphology, and endocytosis, suggesting roles in these processes. Sla2p regulates the Eps15-like Arp2/3 complex activator, Pan1p, controlling actin polymerization during endocytosis. In fission yeast, End4p has been implicated in cellular morphogenesis. Sla2p contains an N-terminal ANTH, a central colied-coil, and a C-terminal actin-binding talin-like (also called I/LWEQ) domains. ANTH domains bind both inositol phospholipids and proteins, and contribute to the nucleation and formation of clathrin coats on membranes. The ANTH domain is a unique module whose N-terminal half is structurally similar to the Epsin N-Terminal Homology (ENTH) and Vps27/Hrs/STAM (VHS) domains, containing a superhelix of eight alpha helices. In addition, it contains a coiled-coil C-terminal half with strutural similarity to spectrin repeats. It binds phosphoinositide PtdIns(4,5)P2 at a short conserved motif K[X]9[K/R][H/Y] between helices 1 and 2. The ANTH domain of Sla2p preferentially binds PtdIns(4,5)P2, which is considered to be an interaction hub in the clathrin interactome. This model describes the N-terminal region of ANTH domains f Sla2p and similar proteins.