Anti-catenin alpha 1 antibodies are used in the immunodetection of the protein encoded by the CTNNA1 gene. In humans, the canonical protein has a reported length of 906 amino acid residues and a mass of 100.1 kDa. Its subcellular localization is in the cell membrane and cytoplasm. Alternative splicing is reported to yield 3 different isoforms for this protein. It is found to be widely expressed in normal tissues. A member of the Vinculin/alpha-catenin protein family, it is reported to associate with the cytoplasmic domain of a variety of cadherins. Post-translational modifications have been described, including sumoylation and phosphorylation. Other names for this target antigen include MDBS2, MDPT2, alpha-E-catenin, catenin (cadherin-associated protein), alpha 1, 102kDa, epididymis secretory sperm binding protein, and CAP102.