Ileal Sodium Bile Acid Cotransporter (ISBT)

The SLC10A2 gene encodes a sodium/bile acid cotransporter. Bile acids are synthesized from cholesterol in the liver and secreted into the small intestine, where they facilitate absorption of fat-soluble vitamins and cholesterol. The majority (more than 90%) of bile acids are reabsorbed from the ileum via uptake via a sodium-gradient-driven transporter in the apical membrane of the ileal enterocyte. The gene encodes a 348-amino acid polypeptide with 7 predicted transmembrane domains and a predicted molecular mass of 38 kD. The native human protein has a relative molecular mass of 40 kD on SDS gel electrophoresis due to N-linked glycosylation.