P-glycoprotein 1 (ABCB1) (PGP1)

P-glycoprotein 1 (ABCB1), also known as Multidrug resistance protein 1 (MDR1), is a critical ATP-dependent efflux pump belonging to the ATP-binding cassette (ABC) transporter superfamily [1, 2]. It is widely expressed in physiological barriers such as the blood-brain barrier, the intestinal epithelium, and the canalicular membrane of hepatocytes, where it serves a protective role by extruding xenobiotics and toxic metabolites [3]. In clinical oncology, P-glycoprotein 1 is a major driver of multidrug resistance, as it efficiently pumps out a diverse range of chemotherapeutic agents, including taxanes and anthracyclines, thereby reducing their therapeutic efficacy [1, 5]. Beyond cancer, its activity is a primary determinant of the pharmacokinetics and safety profiles of many drugs, such as digoxin and loperamide [3, 4]. Inhibition or induction of this transporter is a frequent cause of significant drug-drug interactions, making it a key focus for regulatory agencies during drug development [4, 6]. Sources: [1] UniProt P08183; [2] NCBI Gene 5243; [3] StatPearls: P-glycoprotein; [4] FDA: Drug Development and Drug Interactions; [5] PubMed: Role of ABCB1 in cancer resistance; [6] PubMed: ABCB1 polymorphisms and drug response.

Other names

Multidrug resistance protein 1MDR1ATP-binding cassette sub-family B member 1CD243GP170ABC20

ATP-dependent efflux of substrates from the intracellular space or plasma membrane to the extracellular space