Involved in endocytosis. Interacts with AP1G1 and AP2A1 components of the adapter protein complexes AP-1 and AP-2. Interacts with the GAE domain proteins GGA1, GGA2 and GGA3 (By similarity). Colocalizes with AP-2 at the plasma membrane. 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. The WXXF motif 1, which is preceded by an acidic residue and has a glycine in second position mediates specific interaction with AP-1. The WXXF motif 2, which is followed by the C-terminal carboxyl group negative charge, allows specific interaction with AP-2 (By similarity). The disease is caused by variants affecting the gene represented in this entry. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the NECAP family. Truncated N-terminus.