BCAT1 Recombinant Rabbit mAb (S-4159-9)

BCAT1 (cytosolic branched-chain aminotransferase 1) is a pyridoxal phosphate-dependent enzyme primarily localized in the cytoplasm, encoded by the BCAT1 gene on human chromosome 20. As a key enzyme in the catabolism of branched-chain amino acids (BCAAs), BCAT1 reversibly transfers the amino groups of leucine, isoleucine, and valine to α-ketoglutarate, generating the corresponding branched-chain α-keto acids and glutamate, thereby playing an important role in nitrogen metabolism and energy production. Under physiological conditions, BCAT1 exhibits low-level expression in various tissues outside the liver, but it is significantly upregulated in multiple malignancies, including glioblastoma, making it a key metabolic regulator promoting tumor progression. Mechanistically, BCAT1 overexpression not only provides nitrogen sources and carbon skeletons for tumor cells by enhancing BCAA catabolism, but also directly binds to and inhibits CBX4, a core component of the polycomb repressive complex 1 (PRC1), thereby epigenetically maintaining chromatin accessibility of glutaminase (GLS) and promoting glutamine-dependent pyrimidine synthesis. Furthermore, BCAT1 modulates the α-ketoglutarate/glutamate ratio, affecting global DNA methylation levels and reshaping gene expression profiles to enhance chemotherapy resistance. Notably, the catalytic activity of BCAT1 is finely regulated by phosphorylation of its key residues; for example, phosphorylation of Ser5 and Ser327 activates its function by promoting enzyme-substrate binding or enhancing catalytic efficiency, respectively. These findings reposition BCAT1 from a conventional metabolic enzyme to a central hub linking BCAA catabolism, epigenetic regulation, and tumor malignant phenotypes, making it a highly promising antitumor therapeutic target.