P-glycoprotein transports corticosterone and is photoaffinity-labeled by the steroid

✍ Scribed by David C. Wolf; Susan Band Horwitz

• Book ID: 102865465
• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: French
• Weight: 842 KB
• Volume: 52
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.2910520125

✦ Synopsis

Multi-drug-resistant cells overproduce a 130-1 80-kDa integral membrane phosphoglycoprotein known as P-glycoprotein which acts as an energy-dependent drug efflux pump. While P-glycoprotein has been shown to transport hydrophobic antitumor drugs out of multi-drug-resistant cells in tissue culture, its endogenous substrates remain unknown. This report shows that 3H-corticosterone can specifically photoaffinity label P-glycoprotein. Furthermore, corticosterone is effluxed from multidrug-resistant cells by P-glycoprotein. These data suggest that corticosterone may be an endogenous substrate for P-glycoprotein.