Isolation of a novel human canalicular multispecific organic anion transporter, cMOAT2/MRP3, and its expression in cisplatin-resistant cancer cells with decreased ATP-dependent drug transport

Biochem Biophys Res Commun. 1998 Nov 9;252(1):103-10. doi: 10.1006/bbrc.1998.9546.


The human multidrug resistance protein (MRP) gene encodes a membrane protein involved in the ATP-dependent transport of hydrophobic compounds. We previously isolated a canalicular multispecific organic anion transporter, cMOAT1/MRP2, that belongs to the ATP binding cassette (ABC) superfamily, which is specifically expressed in liver, and cMOAT1/MRP2 is responsible for the defects in hyperbilirubinemia II/Dubin-Johnson syndrome. In this study, we isolated a new cDNA of the ABC superfamily designated cMOAT2/MRP3 that is homologous to human MRP1 and cMOAT1/MRP2: cMOAT2/MRP3 is 56% identical to MRP1 and 45% identical to cMOAT1/MRP2, respectively. Fluorescence in situ hybridization demonstrated the chromosomal locus of this gene on chromosome 17q22. The human cMOAT2 cDNA hybridized to a 6.5-kb mRNA that was mainly expressed in liver and to a lesser extent in colon, small intestine, and prostate. The cMOAT2/MRP3 gene was not overexpressed in cisplatin-resistant cell lines with increased ATP-dependent transport of cisplatin over their parental counterparts derived from human head and neck cancer and human prostatic cancer cell lines. The human cMOAT2/MRP3, a novel member of the ABC superfamily, may function as a membrane transporter in liver, colon, and prostate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Amino Acid Sequence
  • Anion Transport Proteins
  • Base Sequence
  • Carrier Proteins / biosynthesis
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cisplatin / toxicity*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Drug Resistance, Neoplasm*
  • Female
  • Humans
  • KB Cells
  • Male
  • Molecular Sequence Data
  • Multidrug Resistance-Associated Protein 2
  • Multidrug Resistance-Associated Proteins*
  • MutS Homolog 3 Protein
  • Organ Specificity
  • Pregnancy
  • Prostatic Neoplasms
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transcription, Genetic
  • Tumor Cells, Cultured


  • ABCC2 protein, human
  • Anion Transport Proteins
  • Carrier Proteins
  • DNA-Binding Proteins
  • MSH3 protein, human
  • Multidrug Resistance-Associated Protein 2
  • Multidrug Resistance-Associated Proteins
  • MutS Homolog 3 Protein
  • Adenosine Triphosphate
  • Cisplatin
  • multidrug resistance-associated protein 1