AP1S1, AP19, CLAPS1, AP-1 complex subunit sigma-1A, Adapter-related protein complex 1 sigma-1A subunit, Adaptor protein complex AP-1 sigma-1A subunit, Clathrin assembly protein complex 1 sigma-1A small chain, Clathrin coat assembly protein AP19, Golgi adaptor HA1/AP1 adaptin sigma-1A subunit, HA1 19kD subunit, Sigma 1a subunit of AP-1 clathrin, Sigma-adaptin 1A, Sigma1A-adaptin

AP1S1 is part of the clathrin coat assembly complex which links clathrin to receptors in coated vesicles. These vesicles are involved in endocytosis and Golgi processing. This protein, as well as beta-prime-adaptin, gamma-adaptin, and the medium (mu) chain AP47, form the AP-1 assembly protein complex located at the Golgi vesicle.