Adaptor Related Protein Complex 3 Beta 1 (AP3b1)

AP3b1 encodes a protein that may play a role in organelle biogenesis associated with melanosomes, platelet dense granules, and lysosomes.The encoded protein is part of the heterotetrameric AP-3 protein complex which interacts with the scaffolding protein clathrin. The 1,094-amino acid beta-3A-adaptin protein shares 61% identity with beta-NAP and is also related to the beta-1- (AP1B1) and beta-2-adaptin (AP2B1) subunits of complexes AP1 and AP2, respectively. The central hydrophilic region of beta-3A-adaptin is rich in acidic and serine residues and contains many potential sites for phosphorylation; the authors demonstrated that beta-3A-adaptin is phosphorylated in vivo on serine residues.