Subunit of clathrin-associated adaptor protein complex 1 that plays a role in protein sorting in the late-Golgi/trans-Golgi network (TGN) and/or endosomes. The AP complexes mediate both the recruitment of clathrin to membranes and the recognition of sorting signals within the cytosolic tails of transmembrane cargo molecules.
Defects in AP1S2 are the cause of mental retardation X-linked type 59 (MRX59) [MIM:300630]. It is characterized by significantly sub-average general intellectual functioning associated with impairments in adaptative behavior and manifested during the developmental period. In contrast to syndromic or specific X-linked mental retardation which also present with associated physical, neurological and/or psychiatric manifestations, intellectual deficiency is the only primary symptom of non-syndromic X-linked mental retardation. MRX59 consists of a mild-to-profound mental retardation. Other features includes hypotonia early in life and delay in walking.
Belongs to the adaptor complexes small subunit family.
Golgi apparatus. Cytoplasmic vesicle membrane. Membrane > clathrin-coated pit. Component of the coat surrounding the cytoplasmic face of coated vesicles located at the Golgi complex.