Multidrug-resistance P-glycoprotein (MDR1) secretes platelet-activating factor

Multidrug-resistance P-glycoprotein (MDR1) secretes platelet-activating factor.

The human multidrug-resistance (MDR1) P-glycoprotein (Pgp) is an ATP-binding-cassette transporter (ABCB1) that is ubiquitously expressed. Often its concentration is high in the plasma membrane of cancer cells, where it causes multidrug resistance by pumping lipophilic drugs out of the cell. In addition, MDR1 Pgp can transport analogues of membrane lipids with shortened acyl chains across the pl...

Multidrug Resistance Protein (P-Glycoprotein; MDR1)

Secretion of platelet-activating factor is mediated by MDR1 P-glycoprotein in cultured human mesangial cells.

MDR1 P-glycoprotein (Pgp), the product of the MDR1 gene involved in multidrug resistance in cancer cells, is also expressed in normal tissues. In the human kidney, it is localized in the mesangium, the proximal tubule, the thick ascending limb of Henle's loop, and the collecting duct. Pgp actively transports lipophilic xenobiotics, peptides, steroids, and lipids, and perhaps endogenous substrat...

Overcoming multidrug drug resistance in P-glycoprotein/MDR1-overexpressing cell lines by ecteinascidin 743.

Ecteinascidin 743 (Et-743) is a novel anticancer agent forming covalent guanine adducts at specific sites in the DNA minor groove. Et-743 has a unique mechanism of action because it kills cancer cells by poisoning transcription-coupled nucleotide excision repair. Recent studies suggested a complex relationship between P-glycoprotein (P-gp)/MDR1 and Et-743. On one hand, Et-743 was reported to do...

Imaging reversal of multidrug resistance in living mice with bioluminescence: MDR1 P-glycoprotein transports coelenterazine.

Coelenterazine is widely distributed among marine organisms, producing bioluminescence by calcium-insensitive oxidation mediated by Renilla luciferase (Rluc) and calcium-dependent oxidation mediated by the photoprotein aequorin. Despite its abundance in nature and wide use of both proteins as reporters of gene expression and signal transduction, little is known about mechanisms of coelenterazin...