LIG_AP2alpha_2

AP2 alpha ligands

Motifs responsible for the binding of accessory endocytic proteins to the alpha-subunit of adaptor protein AP-2 and their recruitment to the site of clathrin coated vesicle formation.

The DPF/W motif binds the appendage of both alpha and beta subunits of AP2 adaptor complex (alpha2 and beta2 adaptin respectively). It is found on proteins involved in the control of clathrin coated vesicle (CCV) formation at sites of coated pits formation, allowing their recruitment to the site of CCV formation. Its binding site is a conserved patch on the platform subdomain of alpha2 and beta2 adaptins. Owen,2000 showed that if alpha and beta 2 adaptin share some ligands, they bind to them with different relative affinities. The difference in specificity is probably due to the different chemical properties of the residues surrounding the conserved binding site on the platform domain. For a given protein, the affinity of binding to alpha-adaptin appears to be correlated to the number of DPF/W motifs. Indeed Eps15, Epsin which contain several copies of the motif bind more tightly than amphiphysin, AP180 and auxilin which contain fewer copies (Owen,1999).

Alpha_adaptin_C (PF02296) Alpha adaptin AP2, C-terminal domain (Stochiometry: 1 : 1)

PDB Structure: 1KY6