These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Molecular characterization and functional regulation of a novel rat liver-specific organic anion transporter rlst-1.
    Author: Kakyo M, Unno M, Tokui T, Nakagomi R, Nishio T, Iwasashi H, Nakai D, Seki M, Suzuki M, Naitoh T, Matsuno S, Yawo H, Abe T.
    Journal: Gastroenterology; 1999 Oct; 117(4):770-5. PubMed ID: 10500057.
    Abstract:
    BACKGROUND & AIMS: Recently, we isolated a new complementary DNA (cDNA) encoding human liver-specific organic anion transporter (LST-1), representing the multispecificity of human liver. The aim of this study was to isolate a rat counterpart of human LST-1 and examine the expression regulation of its messenger RNA (mRNA) to clarify the molecular basis of cholestasis. METHODS: A rat liver cDNA library was screened with human LST-1 cDNA as a probe. Xenopus oocyte expression system was used for functional analysis. Northern blot analyses were performed using the isolated cDNA (termed rlst-1). The bile duct ligation model and the cecum ligation and puncture model were used for expression analyses. RESULTS: rlst-1 encodes 652 amino acids, predicting at least 11 transmembrane regions. The overall homology with human LST-1 was 60.2%, which is the highest among all known organic anion transporters. rlst-1 also belongs to the same new gene family as human LST-1, located between the organic anion transporter family and the prostaglandin transporter. rlst-1 preferably transports taurocholate (K(m), 9.45 micromol/L) in an Na(+)-independent manner. The rlst-1 mRNA is exclusively expressed in the liver. In both the bile duct ligation model and the cecum ligation and puncture model, mRNA expression levels of rlst-1 were down-regulated. CONCLUSIONS: rlst-1 is a counterpart of human LST-1 and is one of the important transporters in rat liver for the clearance of bile acid. The expression of rlst-1 may be under feedback regulation of cholestasis by biliary obstruction and/or sepsis.
    [Abstract] [Full Text] [Related] [New Search]