Anti-Syntaxin 1A antibodies are used in the immunodetection of the protein encoded by the STX1A gene. In humans, the canonical protein has a reported length of 288 amino acid residues and a mass of 33 kDa. Its subcellular localization is in the cytoplasmic vesicles and cell membrane. Alternative splicing is reported to yield 3 different isoforms for this protein. A member of the Syntaxin protein family, it is known to play an important role in hormone and neurotransmitter calcium-dependent exocytosis and endocytosis. Post-translational modifications have been described, including sumoylation and phosphorylation. Other names for this target antigen include P35-1, STX1, SYN1A, neuron-specific antigen HPC-1, syntaxin 1A (brain), and HPC-1.