AP2sigma is one of a suBunit of the adaptor protein complex 2 (AP-2) . The AP-2 complex has Been generally thought to function as a heterotetramer, consisting of two large (a/A and B/B) ( At4G11380) , one medium (m/M) ( At5g46630) , and one small (s/S) ( At1g47830) suBunit(s) . AP-2 is involved in clathrin-dependent endocytosis in which cargo proteins are incorporated into vesicles surrounded By clathrin (clathrin-coated vesicles, CCVs) which are destined for fusion with the early endosome.
