Anti-SMG1 nonsense mediated mRNA decay associated PI3K related kinase antibodies are used for the immunodetection of the protein encoded by the SMG1 gene. In humans, the canonical protein has a reported length of 3661 amino acid residues and a mass of 410.5 kDa. Its subcellular localization is in the nucleus and cytoplasm. Alternative splicing is reported to yield 4 different isoforms for this protein. It is found to be widely expressed, with highest level in the heart and skeletal muscle. A member of the PI3/PI4-kinase protein family, it is a serine/threonine protein kinase involved in both mRNA surveillance and genotoxic stress response pathways. Post-translational modifications have been described, including phosphorylation. Other names for this target antigen include ATX, serine/threonine-protein kinase SMG1, PI-3-kinase-related kinase SMG-1, and 61E3.4. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.