ABCB11/BRIC2/BSEP [MD122]

Bile salt export pump (UniProt O95342; also known as ATP-binding cassette sub-family B member 11, Sister of P-glycoprotein) is encoded by the ABCB11 (also known as BRIC2, BSEP, PFIC2, SPGP) gene (Gene ID 8647) in human. Bile is produced by hepatocytes in the liver and released into the biliary system of ducts and gallbladder. After food ingestion, bile is released in the form of mixed micelles of salts and phospholipids into the duodenum where its detergent properties act to solubilize lipids to help their absorption by the intestine. Bile salt export pump is an ATP-binding cassette (ABC) family member localized to the hepatocyte canalicular membrane where it plays an important role in the bile salt-dependent bile flow and the normal enterohepatic circulation of bile salts from the distal intestine back to the liver. ABCB11/BSEP gene mutations are associated with progressive familial intrahepatic cholestasis type 2 (PFIC2), benign recurrent intrahepatic cholestasis type 2 (BRIC2), drug-induced cholestasis, hormone-dependent intrahepatic cholestasis of pregnancy (ICP), biliary lithiasis, and transient neonatal cholestasis, as a result of impaired bile flow. Bile salt export pump is a 12-transmembrane protein (a.a. 63-83, 148-168, 216-236, 241-261, 320-340, 354-374, 756-776, 795-815, 870-890, 891-911, 980-1000, 1012-1032) with both its N- and C-terminal ends exposed cyroplasmically (a.a. 1-62 and 1033-1321).