Essential component of the Ost-alpha/Ost-beta complex, a heterodimer that acts as the intestinal basolateral transporter responsible for bile acid export from enterocytes into portal blood . Modulates SLC51A glycosylation, membrane trafficking and stability activities . The Ost-alpha/Ost-beta complex efficiently transports the major species of bile acids (taurocholate) . Taurine conjugates are transported more efficiently across the basolateral membrane than glycine-conjugated bile acids (By similarity). Can also transport steroids such as estrone 3-sulfate and dehydroepiandrosterone 3-sulfate, therefore playing a role in the enterohepatic circulation of sterols . Able to transport eicosanoids such as prostaglandin E2 (By similarity).
Subcellular locations: Cell membrane
Mainly restricted to the lateral and basal membranes of ileal enterocytes.
Widely expressed with a high expression in ileum. Expressed in testis, colon, liver, small intestine, kidney, ovary and adrenal gland; and at low levels in heart, lung, brain, pituitary, thyroid gland, uterus, prostate, mammary gland and fat.