A P-glycoprotein homologue of Plasmodium falciparum is localized on the digestive vacuole

Abstract

Resistance to chloroquine in Plasmodium falciparum bears a striking similarity to the multi-drug resistance (MDR) phenotype of mammalian tumor cells which is mediated by overexpression of P-glycoprotein. We show here that the P. falciparum homologue of the P-glycoprotein (Pghl) is a 160,000-D protein that is expressed throughout the asexual erythrocytic life cycle of the parasite. Quantitative immunoblotting analysis has shown that the protein is expressed at approximately equal levels in chloroquine resistant and sensitive isolates suggesting that overexpression of Pghl is not essential for chloroquine resistance. The chloroquine-resistant cloned line FAC8 however, does express approximatel..