Anti-threonyl-tRNA synthetase 3 antibodies are used for the immunodetection of the protein encoded by the TARS3 gene. In humans, the canonical protein has a reported length of 802 amino acid residues and a mass of 92.6 kDa. Its subcellular localization is in the nucleus and cytoplasm. Alternative splicing is reported to yield 2 different isoforms for this protein. A member of the Class-II aminoacyl-tRNA synthetase protein family, it is known to catalyze the attachment of threonine to tRNA(Thr) in a two-step reaction: threonine is first activated by ATP to form Thr-AMP and then transferred to the acceptor end of tRNA(Thr). Other names for this target antigen include probable threonine--tRNA ligase 2, cytoplasmic, probable threonyl-tRNA synthetase 2, cytoplasmic, thrRS, threonyl-tRNA synthetase like 2, and threonine--tRNA ligase 2, cytoplasmic. Gene orthologs have been identified in the mouse, rat, bovine, zebrafish, chimpanzee and chicken species.