Evolution of substrate specificity for the bile salt transporter ASBT (SLC10A2).

ABSTRACT: The apical Na(+)-dependent bile salt transporter (ASBT/SLC10A2) is essential for maintaining the enterohepatic circulation of bile salts. It is not known when Slc10a2 evolved as a bile salt transporter or how it adapted to substantial changes in bile salt structure during evolution. We characterized ASBT orthologs from two primitive vertebrates, the lamprey that utilizes early 5α-bile alcohols and the skate that utilizes structurally different 5β-bile alcohols, and compared substrate specificity with ASBT from humans who utilize modern 5β-bile acids. Everted gut sacs of skate but not the more primitive lamprey transported (3)H-taurocholic acid (TCA), a modern 5β-bile acid. However, molecular cloning identified ASBT orthologs from both species. Cell-based assays using recombinant ASBT/Asbt'

SUBMITTER: Lionarons DA 

PROVIDER: S-EPMC3540847 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature