B3GAT1
Description
The B3GAT1 (beta-1,3-glucuronyltransferase 1) is a protein-coding gene located on chromosome 11.
B3GAT1 (3-beta-glucuronosyltransferase 1) is a human enzyme encoded by the B3GAT1 gene. This enzyme is responsible for creating the CD57 epitope on other cell surface proteins. CD57, also known as HNK1 (human natural killer-1) or LEU7, is a carbohydrate epitope containing a sulfoglucuronyl residue found on various adhesion molecules within the nervous system. B3GAT1 belongs to the glucuronyltransferase gene family, known for their strict acceptor specificity towards nonreducing terminal sugars and their anomeric linkages. This gene product acts as the key enzyme in the glucuronyl transfer reaction during HNK-1 biosynthesis. In anatomical pathology, CD57 (immunostaining) is used to differentiate neuroendocrine tumors from other types. CD57 positive cells, typically T cells or NK cells, are found in lymph nodes, tonsils, and the spleen.
B3GAT1 is an enzyme that plays a crucial role in the synthesis of the L2/HNK-1 carbohydrate epitope on glycoproteins. This epitope is commonly found on cell surface proteins in the nervous system. B3GAT1 can also contribute to glycosaminoglycan biosynthesis. Its substrates include asialo-orosomucoid (ASOR), asialo-fetuin, and asialo-neural cell adhesion molecule. B3GAT1 requires sphingomyelin for optimal activity, with saturated fatty acids like stearoyl-sphingomyelin being particularly effective. Unsaturated fatty acids, however, do not support its activity, regardless of their chain length. B3GAT1 functions as a homodimer and interacts with the SAR1A protein.
B3GAT1 is also known as CD57, GLCATP, GLCUATP, HNK1, LEU7, NK-1, NK1.
