M4688-25C

Goat Anti-MRP4 (Multidrug Resistance-associated Protein 4, ATP-binding Cassette Sub-family C (CFTR/MRP) Member 4, ATP Binding Cassette Sub-family C Member 4, ABCC4, bA464I2.1, Canalicular Multispecific Organic Anion Transporter ABC Superfamily, Canalicular Multispecific Organic Anion Transporter, EST170205, MRP/cMOAT Related ABC Transporter, Multispecific Organic Anion Transporter B, MOATB, RP11-74A12.1)

Proteins involved in MDR mechanisms are P-glycoprotein (Pgp), Multidrug Resistance-associated Protein (MRP) and Lung Resistance-related Protein (LRP). Pgp and MRP belong to the ATP binding cassette (ABC) superfamily of membrane transporter proteins. This superfamily comprises a broad range of proteins found in organisms from bacteria to humans, which transport a wide variety of substances such as ions, amino acids, sugars, peptide and proteins. Although increased levels of Pgp are likely to contribute to MDR in at least some tumor types, it has become evident that alternative, non-Pgp-mediated mechanisms of MDR exist. The multidrug resistance-associated protein (MRP1) has been identified by Cole and Deeley. The amino acid identity between MRP1 and Pgp is only 15%, and the homology to chloride channel CFTR only 19%. Paulusma, et al., cloned the cDNA for rat canalicular multispecific organic anion transporter (cMOAT or MRP2) which turned out to be a novel liver specific homolog of human MRP1. Recently, by screening database of human expressed sequences tags, Kool identified three new homologs of MRP1, called MRP3, MRP4 and MRP5. Several excellent reviews appeared recently dealing with mechanisms of cellular drug resistance. In addition to MDR-related proteins many other mechanisms of drug resistance have been documented in vitro. They are based on alterations in drug target enzymes and proteins, increased detoxification, alterations in cellular metabolism, enhanced ability to repair DNA damage, and failure to undergo apoptosis.