Preclinical/Animal Transporters

Asbt - rat

Asbt (apical sodium-dependent bile acid transporter), rat


Aliases: IBAT, ISBAT, ISBT
Gene name: Solute carrier family 10 member 2 (Slc10a2)


Rat ileal sodium-dependent bile acid cotransporter was cloned and expressed in Xenopus oocytes in 1995 [1]. The human and rat orthologues share 83% amino acid homology. Expression of rAsbt has been shown on the apical surface of ileal enterocytes, renal proximal tubular cells and cholangiocytes, similar to the human protein [2-4]. An alternatively spliced variant named t-Asbt is localized to the basolateral domain of cholangiocytes, ileal enterocytes, and renal tubular epithelial cells. This truncated variant exhibited activity as a taurocholic acid efflux carrier in in vitro experiments in Xenopus oocytes [5]. Regulation of both variants by bile acids was investigated by several groups, but no consensus was achieved as to whether a negative feedback regulatory mechanism similar to mice and humans exists [6-9].


References


1.    Shneider, B.L., et al., Cloning and molecular characterization of the ontogeny of a rat ileal sodium-dependent bile acid transporter. J Clin Invest, 1995. 95(2): p. 745-54.
2.    Lazaridis, K.N., et al., Rat cholangiocytes absorb bile acids at their apical domain via the ileal sodium-dependent bile acid transporter. J Clin Invest, 1997. 100(11): p. 2714-21.
3.    Christie, D.M., et al., Comparative analysis of the ontogeny of a sodium-dependent bile acid transporter in rat kidney and ileum. Am J Physiol, 1996. 271(2 Pt 1): p. G377-85.
4.    Kullak-Ublick, G.A., B. Stieger, and P.J. Meier, Enterohepatic bile salt transporters in normal physiology and liver disease. Gastroenterology, 2004. 126(1): p. 322-42.
5.    Lazaridis, K.N., et al., Alternative splicing of the rat sodium/bile acid transporter changes its cellular localization and transport properties. Proc Natl Acad Sci U S A, 2000. 97(20): p. 11092-7.
6.    Kip, N.S., et al., Differential expression of cholangiocyte and ileal bile acid transporters following bile acid supplementation and depletion. World J Gastroenterol, 2004. 10(10): p. 1440-6.
7.    Chen, F., et al., Liver receptor homologue-1 mediates species- and cell line-specific bile acid-dependent negative feedback regulation of the apical sodium-dependent bile acid transporter. J Biol Chem, 2003. 278(22): p. 19909-16.
8.    Arrese, M., et al., Neither intestinal sequestration of bile acids nor common bile duct ligation modulate the expression and function of the rat ileal bile acid transporter. Hepatology, 1998. 28(4): p. 1081-7.
9.    Shneider, B.L., Intestinal bile acid transport: biology, physiology, and pathophysiology. J Pediatr Gastroenterol Nutr, 2001. 32(4): p. 407-17.

 

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