B3GAT1

B3GAT1, or Beta-1,3-glucuronyltransferase 1, is an enzyme in humans that is encoded by the B3GAT1 gene. It belongs to the glycosyltransferase family, a group of enzymes that catalyze the transfer of monosaccharides from nucleotide sugars to acceptor molecules, forming glycosidic bonds.

B3GAT1 specifically transfers glucuronic acid (GlcA) in a beta-1,3 linkage to N-acetylglucosamine (GlcNAc). This enzymatic activity is crucial in the biosynthesis of the HNK-1 carbohydrate epitope. The HNK-1 epitope (also known as CD57 or Leu-7 antigen) is a sulfated trisaccharide (3-O-sulfoglucuronyl-N-acetyl-lactosamine) found on a variety of glycoproteins and glycolipids in the nervous system, immune system, and other tissues. It plays roles in cell adhesion, cell migration, and neurite outgrowth.

The B3GAT1 gene is located on chromosome 11 in humans. Mutations in this gene have been associated with certain neurological disorders, highlighting the importance of the enzyme's function in normal development and physiology. Research into B3GAT1 continues to explore its specific substrates, regulatory mechanisms, and the precise functions of the HNK-1 epitope in various biological processes.