The MRP-related and BCRP/ABCG2 multidrug resistance proteins: biology, substrate specificity and regulation

Curr Drug Metab. 2004 Feb;5(1):21-53. doi: 10.2174/1389200043489199.


Several members of different families of the ATP-binding cassette (ABC) superfamily of transport proteins are capable of transporting an extraordinarily structurally diverse array of endo- and xenobiotics and their metabolites across cell membranes. Together, these transporters play an important role in the absorption, disposition and elimination of these chemicals in the body. In tumor cells, increased expression of these drug transporters is associated with resistance to multiple chemotherapeutic agents. In this review, current knowledge of the biochemical, physiological and pharmacological properties of nine members of the multidrug resistance protein (MRP)-related ABCC family (MRP1, MRP2, MRP3, MRP4, MRP5, MRP6, MRP7, ABCC11 and ABCC12) as well as the G family member, ABCG2/BCRP, are summarized. A focus is placed on the structural similarities and differences of these drug transporters as well as the molecular determinants of their substrate specificities and transport activities. Factors that regulate expression of the MRP-related proteins and ABCG2/BCRP are also reviewed.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily G, Member 2
  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism
  • ATP-Binding Cassette Transporters / physiology*
  • Biological Transport
  • Drug Resistance, Multiple / genetics
  • Gene Expression Regulation
  • Humans
  • Multidrug Resistance-Associated Proteins / genetics
  • Multidrug Resistance-Associated Proteins / metabolism
  • Multidrug Resistance-Associated Proteins / physiology*
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • Neoplasm Proteins / physiology*
  • Substrate Specificity
  • Xenobiotics / metabolism


  • ABCG2 protein, human
  • ATP Binding Cassette Transporter, Subfamily G, Member 2
  • ATP-Binding Cassette Transporters
  • Multidrug Resistance-Associated Proteins
  • Neoplasm Proteins
  • Xenobiotics