The WXXF motifs mediate binding of accessory proteins to the ear-domain of AP-1, GGAs and AP-2 through hydrophobic interactions. Selective binding to the GAE domains of AP-1 or to the alpha-ear domain of AP-2 is tuned by the acidic context surrounding the motif and the properties of the second residue of the motif itself.
Cytoplasmic vesicle, clathrin-coated vesicle membrane. Cell membrane. Colocalizes with AP-2 at the plasma membrane.