Translocates drugs and phospholipids across the membrane (PubMed:8898203, PubMed:2897240, PubMed:9038218). Catalyzes the flop of phospholipids from the cytoplasmic to the exoplasmic leaflet of the apical membrane. Participates mainly to the flop of phosphatidylcholine, phosphatidylethanolamine, beta-D-glucosylceramides and sphingomyelins (PubMed:8898203). Energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells (PubMed:2897240, PubMed:9038218). ATP + H2O + xenobioticSide 1 = ADP + phosphate + xenobioticSide 2. ATP + H2O + phospholipidSide 1 = ADP + phosphate + phospholipidSide 2. a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(in) + ATP + H2O = a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(out) + ADP + H(+) + phosphate a 1,2-diacyl-sn-glycero-3-phosphocholine(out) + ATP + H2O = a 1,2-diacyl-sn-glycero-3-phosphocholine(in) + ADP + H(+) + phosphate a beta-D-glucosyl-(1<->1')-N-acylsphing-4-enine(in) + ATP + H2O = a beta-D-glucosyl-(1<->1')-N-acylsphing-4-enine(out) + ADP + H(+) + phosphate a sphingomyelin(in) + ATP + H2O = a sphingomyelin(out) + ADP + H(+) + phosphate Translocase activity is inhibited by verapamil and is sensitive to energy depletion. Interacts with PSMB5. Finds in a complex with ABCB1, TFPI2 and PPP2R3C; leading to the dephosphorylation of ABCB1. Expressed in liver, kidney, small intestine and brain. Genetic variation in ABCB1 may play a role in patients who do not respond to drug treatment. Disease susceptibility is associated with variants affecting the gene represented in this entry. Belongs to the ABC transporter superfamily. ABCB family. Multidrug resistance exporter (TC 3.A.1.201) subfamily. P-glycoprotein entry Database for mutations in ABC proteins