P-glycoprotein (gp170) or multidrug-resistance glycoprotein

Function: - P-glycoprotein 1 helps eliminate drugs by pumping them OUT of cells, back into the gut, bile, & urine for excretion - P-glycoprotein 3 transports phosphatidylcholine Pathology: - tumor cells may up-relate P-glycoprotein 1 as a mechanism for development of resistance to antineoplastic agents Pharmacology: - inhibitors include: - antiarrhythmics: amiodarone, quinidine, - macrolides: clarithromycin, erythromycin - calcium channel blockers: - diltiazem, felodipine, nifedipine, verapamil - proton pump inhibitors: lansoprazole, omeprazole & others - SSRI: paroxetine, sertraline - others ciclosporin, colchicine, tamoxifen, ritonavir, danicopan - inducers include rifampicin & St John's wort [2]

Specific

ATP-binding cassette sub-family C member 12 (ATP-binding cassette C12, multidrug resistance-associated protein 9, ATP-binding cassette transporter sub-family C member 12, ABCC12, MRP9) P-glycoprotein 1 (PGY1, multidrug resistance protein 1, MDR1, gp170, ATP-binding cassette subfamily B member 1, ABCB1) P-glycoprotein 2 or multidrug resistance protein 2 P-glycoprotein 3 (PGY3, multidrug resistance protein 3, MDR3, ATP-binding cassette subfamily B member 4, ABC4)

General

adenosine triphosphatase (ATPase) carrier protein (transporter) glycoprotein transmembrane 12 protein

Properties

SIZE: MW = 170 kD COMPARTMENT: cellular membrane MOTIF: N-glycosylation site {EXOPLASMIC-LOOP-1} (2) ATP-binding site NAME: ATP-binding site SITE: CYTOPLASMIC-LOOP-3 S/T phosphorylation site {CYTOPLASMIC-LOOP-3} FOR-PHOSPHORYLATION-BY: protein kinase C ATP-binding site NAME: ATP-binding site SITE: CYTOPLASMIC-TAIL INDUCERS: Hypericum perforatum INHIBITORS: amiodarone clarithromycin cyclosporin A diltiazem erythromycin indinavir itraconazole ketoconazole nicardipine ritonavir verapamil SUBSTRATE: colchicine CYLOSPORIN digoxin diltiazem etoposide glucocorticoid* nicardipine paclitaxel verapamil vinblastine vincristine VINDESINE