ATP-binding cassette sub-family B member 1 (P-glycoprotein) and ATP-binding cassette sub-family G member 2 (Breast cancer resistance protein) (P-gp/BCRP)

P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP) are two of the most significant efflux transporters belonging to the ATP-binding cassette (ABC) superfamily [1, 2]. These proteins are primarily located on the apical membranes of epithelial cells in the intestine, liver, kidney, and at blood-tissue barriers like the blood-brain barrier (BBB), where they function as biological gatekeepers by pumping a wide variety of chemically diverse substrates out of cells [3]. In the context of oncology, their over-expression is a hallmark of multidrug resistance (MDR), as they effectively reduce the intracellular concentration of various chemotherapeutic agents, thereby limiting treatment efficacy [4]. Beyond cancer, P-gp and BCRP play a critical role in determining the absorption, distribution, and excretion (ADME) profiles of numerous drugs [5]. Because they share many overlapping substrates and inhibitors, they are often evaluated together during drug development to predict potential drug-drug interactions and to optimize drug delivery to the central nervous system or tumors [5, 6].

Other names

ABCB1MDR1Multidrug resistance protein 1ABCG2BCRPBreast cancer resistance proteinCD243CDw338Mitoxantrone resistance-associated proteinMXR

ATP-dependent efflux of substrates from the intracellular space or cell membrane to the extracellular environment [3, 4]