Epsin family
epsin family
Epsins are a family of endocytic adaptor proteins composed of 3 paralogs: EPN1, EPN2 and EPN3. Epsins are known to be involved in the first steps of endocytosis in particular there is evidence that they have a specific role in cargo selection and coat assembly. From a structural perspective, epsins share a similar protein structure. They possess an epsin N-terminal homology (ENTH) domain necessary to bind PtdIns(4,5)P2 at the PM, two or three ubiquitin interacting motifs (UIMs) known to bind to ubiquitinated cargoes, and the aspartate-proline-tryptophan (DPW) and asparagine-proline-phenylalanine (NPF) motifs that interact with the clathrin machinery. Since the protein structure of the three isoforms is similar, redundant functions have been observed in endocytosis, regulation of the actin cytoskeleton during clathrin-mediated endocytosis, and development.