mouse monoclonal IgG2a; AP-2σ1 Antibody (5-RY21) is an IgG2a κ mouse monoclonal AP-2 sigma 1 antibody (also designated AP-2σ1 antibody) that detects the AP-2 sigma 1 protein of mouse, rat and human origin by WB, IP and ELISA. AP-2σ1 Antibody (5-RY21) is available as the non-conjugated anti-AP-2 sigma 1 antibody. Adapter-related protein complex 2 (AP-2) is one of the two major clathrin-associated adaptor complexes that links clathrin to receptors in coated vesicles. It interacts with the cytoplasmic tail of membrane proteins, thereby leading to their selection and concentration. This complex has also been shown to bind polyphosphoinositides. Existing as a heterotetramer, AP-2 is comprised of two large chains, a medium chain and a small chain. Adapter-related protein complex 2 subunit sigma-1 (AP-2σ1), also known as clathrin coat assembly protein AP17 or sigma2-adaptin, is the 142 amino acid protein small chain of the AP-2 complex. Localized to the cytoplasmic side of the cell membrane, two named isoforms of AP-2σ1 exist as a result of alternative splicing events.