Multidrug resistance efflux pump (MDR efflux pump)

Multidrug resistance (MDR) efflux pumps are specialized membrane proteins that actively transport a wide variety of structurally diverse compounds, including toxins and drugs, out of the cell (UniProt: P08183; PMID: 25833251). In bacteria, these pumps, such as the Resistance-nodulation-division (RND) family, represent a primary mechanism of antibiotic resistance by lowering intracellular drug concentrations (PMID: 30143505). In humans, members of the ATP-binding cassette (ABC) transporter family, like P-glycoprotein (ABCB1), are frequently overexpressed in cancer cells, leading to chemotherapy failure (NIH: StatPearls - P-glycoprotein). \n\nThese pumps play critical physiological roles in protecting sensitive organs like the brain by maintaining the blood-brain barrier and facilitating detoxification in the liver and kidneys (PMID: 15907919). Targeting these pumps with efflux pump inhibitors (EPIs) like Tariquidar or Elacridar aims to restore the sensitivity of resistant cells to existing drugs (PubChem: CID 119171). However, the clinical development of these inhibitors has been hindered by significant safety concerns, including increased systemic toxicity of co-administered drugs and the disruption of essential physiological barriers (PMID: 22641023).

Other names

Efflux transporterMultidrug transporterXenobiotic transporterABC transporterRND pumpP-glycoproteinMultidrug resistance protein

Inhibition of substrate binding, inhibition of ATP hydrolysis, or dissipation of the proton motive force to prevent the active extrusion of therapeutic agents from the cell (PMID: 25833251; NIH: StatPearls).