Mutations in the Plasmodium falciparum chloroquine resistance transporter, PfCRT, enlarge the parasite's food vacuole and alter drug sensitivities.

Abstract

Mutations in the Plasmodium falciparum chloroquine resistance transporter, PfCRT, are the major determinant of chloroquine resistance in this lethal human malaria parasite. Here, we describe P. falciparum lines subjected to selection by amantadine or blasticidin that carry PfCRT mutations (C101F or L272F), causing the development of enlarged food vacuoles. These parasites also have increased sensitivity to chloroquine and some other quinoline antimalarials, but exhibit no or minimal change in sensitivity to artemisinins, when compared with parental strains. A transgenic parasite line expressing the L272F variant of PfCRT confirmed this increased chloroquine sensitivity and enlarged food vacuole phenotype. Furthermore, the introduction of the C101F or L272F mutation into a chloroquine-resistant variant of PfCRT reduced the ability of this protein to transport chloroquine by approximately 93 and 82%, respectively, when expressed in Xenopus oocytes. These data provide, at least in part, a mechanistic explanation for the increased sensitivity of the mutant parasite lines to chloroquine. Taken together, these findings provide new insights into PfCRT function and PfCRT-mediated drug resistance, as well as the food vacuole, which is an important target of many antimalarial drugs.

• Authors: Serena Pulcini, Henry M Staines, Andrew H Lee, Sarah H Shafik, Guillaume Bouyer, Catherine M Moore, Daniel A Daley, Matthew J Hoke, Lindsey M Altenhofen, Heather J Painter, Jianbing Mu, David J P Ferguson, Manuel Llinás, Rowena E Martin, David A Fidock, Roland A Cooper, Sanjeev Krishna
• Journal: Scientific reports (Sci Rep) Vol. 5 Pg. 14552 (Sep 30 2015) ISSN: 2045-2322 [Electronic] England
• PMID: 26420308 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Antimalarials
• Membrane Transport Proteins
• PfCRT protein, Plasmodium falciparum
• Protozoan Proteins
• Chloroquine

Topics

• Amino Acid Substitution
• Animals
• Antimalarials (pharmacology)
• Biological Transport
• Chloroquine (pharmacology)
• Drug Resistance (genetics)
• Humans
• Membrane Transport Proteins (chemistry, genetics)
• Mutation
• Oocytes (metabolism)
• Parasitic Sensitivity Tests
• Plasmodium falciparum (drug effects, physiology)
• Protozoan Proteins (chemistry, genetics)
• Vacuoles (metabolism)
• Xenopus laevis