As part of AP-5, a probable fifth adaptor protein complex it may be involved in endosomal transport. According to PubMed:18395520, it may play a role in cell death. {ECO:0000269|PubMed:18395520, ECO:0000269|PubMed:22022230}. This is the function of AP5M1 (adaptor related protein complex 5 subunit mu 1, ENSG00000053770).