Adaptor Related Protein Complex 1 Sigma 2 (AP1s2)

Adaptor protein complex 1 is found at the cytoplasmic face of coated vesicles located at the Golgi complex, where it mediates both the recruitment of clathrin to the membrane and the recognition of sorting signals within the cytosolic tails of transmembrane receptors. This complex is a heterotetramer composed of two large, one medium, and one small adaptin subunit. AP1s2 serves as the small subunit of this complex and is a member of the adaptin protein family. Transcript variants utilizing alternative polyadenylation signals exist for this gene.The predicted 157-amino acid protein shares 87% identity with human AP19. In yeast 2-hybrid assays, sigma-1B interacted with both gamma-adaptin and gamma-2-adaptin. Northern blot analysis revealed that SIGMA1B was expressed ubiquitously in human tissues.