Multidrug resistance-associated protein 2

Multidrug resistance-associated protein 2 (MRP2), also known as ABCC2, is a protein that in humans is encoded by the ABCC2 gene. MRP2 is a member of the ABC transporter superfamily and is primarily found in the liver, where it plays a crucial role in the biliary excretion of glucuronide conjugates of drugs and endogenous substances.

Structure

MRP2 is a large protein, consisting of 1545 amino acids, with a molecular weight of approximately 174 kDa. It is composed of two homologous halves, each containing six transmembrane domains and two nucleotide-binding domains.

Function

MRP2 is an efflux pump that transports a wide variety of substrates across extra- and intracellular membranes. These substrates include glutathione, glucuronide, and sulfate conjugates of many endogenous and exogenous compounds. MRP2 is also involved in the transport of bile acids and bilirubin in the liver, contributing to the formation of bile.

Clinical significance

Mutations in the ABCC2 gene can lead to Dubin-Johnson syndrome, a rare, autosomal recessive disorder characterized by chronic, benign, intermittent jaundice. In addition, altered expression or function of MRP2 can contribute to multidrug resistance in cancer cells, limiting the effectiveness of chemotherapy.

See also

• ABC transporter
• Dubin-Johnson syndrome
• Multidrug resistance