Epsin N-Terminal Homology (ENTH) domain of Epsin-related protein
Epsin-related protein (EpsinR) is also called clathrin interactor 1 (Clint), enthoprotin, or epsin-4. It is a clathrin-coated vesicle (CCV) protein that binds to membranes enriched in phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2), clathrin, and the gamma appendage domain of the adaptor protein complex 1 (AP1). It contains an Epsin N-Terminal Homology (ENTH) domain, an evolutionarily conserved protein module found primarily in proteins that participate in clathrin-mediated endocytosis. The ENTH domain is highly similar to the N-terminal region of the AP180 N-Terminal Homology (ANTH_N) domain. ENTH and ANTH_N domains are structurally similar to the VHS domain and are composed of a superhelix of eight alpha helices. ENTH domains bind both, inositol phospholipids with preference for PtdIns(4,5)P2, and proteins, and contribute to the nucleation and formation of clathrin coats on membranes. ENTH domains also function in the development of membrane curvature through lipid remodeling during the formation of clathrin-coated vesicles. The ENTH domain of human epsinR binds directly to the helical bundle domain of the mouse SNARE Vti1b; soluble NSF attachment protein receptors (SNAREs) are type II transmembrane proteins that have critical roles in providing the specificity and energy for transport-vesicle fusion. Specific ENTH domains may also function as protein cargo selection/recognition modules. ENTH and ANTH (E/ANTH)-containing proteins have recently been shown to function with adaptor protein-1 and GGA adaptors at the Trans-Golgi Network, which suggests that E/ANTH domains are universal components of the machinery for clathrin-mediated membrane budding.
Feature 1:phosphoinositide binding site [chemical binding site]
Evidence:
Comment:based on the binding of Rattus norvegicus Epsin ENTH domain to inositol 1,4,5-trisphosphate
Comment:ENTH domains bind phosphoinositides (PtdInsPs), usually with a preference for PdtIns(4,5)P2, although not all ENTH domains show this preference.