Functional expression of the rat liver canalicular isoform of the multidrug resistance-associated protein

FEBS Lett. 1997 Apr 7;406(1-2):75-8. doi: 10.1016/s0014-5793(97)00245-7.


The rat hepatocanalicular isoform (called mrp2) of the human multidrug resistance-associated protein (MRP) has been cloned and transiently expressed in COS-7 cells and in Xenopus laevis oocytes. In both systems mrp2 expression induced a markedly increased efflux of intracellularly formed [14C]2,4-dinitrophenyl-S-glutathione. Injection of mrp2 cRNA into oocytes also stimulated efflux of [3H(N)]leukotriene C4. Furthermore, mrp2 mRNA was markedly decreased in the liver of the transport mutant TR rat, which has a congenital defect in the biliary excretion of glutathione-S conjugates and of other divalent organic anions. The study provides a direct demonstration of mrp2-mediated transport function and supports the concept that mrp2 represents the canalicular multispecific organic anion transporter (cMOAT) of mammalian liver.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics*
  • Animals
  • Bile Canaliculi / metabolism*
  • Biological Transport
  • Cell Line
  • Cloning, Molecular
  • Dinitrochlorobenzene / metabolism
  • Humans
  • Leukotriene C4 / metabolism
  • Liver / metabolism*
  • Male
  • Multidrug Resistance-Associated Proteins
  • Rats
  • Rats, Sprague-Dawley


  • ATP-Binding Cassette Transporters
  • Dinitrochlorobenzene
  • Multidrug Resistance-Associated Proteins
  • Leukotriene C4