ATP-binding cassette sub-family B member 1 (P-glycoprotein 1) (ABCB1)

ATP-binding cassette sub-family B member 1 (ABCB1), also known as P-glycoprotein 1 (P-gp), is a 170 kDa transmembrane protein that functions as an ATP-dependent efflux pump (UniProt, P08183). It is widely expressed in the apical membranes of the intestine, liver, kidney, and the endothelial cells of the blood-brain barrier, where it serves a protective role by limiting the absorption and promoting the excretion of xenobiotics (NCBI Gene, 5243). In clinical oncology, ABCB1 is frequently overexpressed in various cancers, leading to multidrug resistance (MDR) by actively transporting chemotherapeutic agents like taxanes and vinca alkaloids out of malignant cells (PubMed, PMID: 30103456). Beyond its role in cancer, ABCB1 is a major determinant of drug pharmacokinetics and a frequent site of drug-drug interactions, as many common medications act as its substrates, inhibitors, or inducers (StatPearls, NBK556133). Therapeutic efforts to inhibit ABCB1 to reverse drug resistance have faced challenges due to systemic toxicity and the protein's broad substrate specificity (PubMed, PMID: 32824015). Understanding ABCB1 activity is essential for predicting drug distribution and ensuring patient safety in polypharmacy scenarios.

Other names

P-glycoprotein 1P-gpMultidrug resistance protein 1MDR1CD243GP170ATP-binding cassette sub-family B member 1

ABCB1 utilizes the energy derived from ATP hydrolysis to transport a broad spectrum of hydrophobic substrates across the cell membrane against a concentration gradient, thereby reducing intracellular drug concentrations (UniProt, P08183).