title: 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.affiliation: Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK.
authors.forename: Serena
authors.initials: S
authors.lastname: Pulcini
authors.affiliation: Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK.
authors.forename: Henry M
authors.initials: HM
authors.lastname: Staines
authors.affiliation: Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Lee
authors.affiliation: Research School of Biology, Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Sarah H
authors.initials: SH
authors.lastname: Shafik
authors.affiliation: Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK.|Sorbonne Universités, UPMC Univ. Paris 06, UMR 8227, Integrative Biology of Marine Models, Comparative Physiology of Erythrocytes, Station Biologique de Roscoff, Roscoff, France.|CNRS, UMR 8227, Integrative Biology of Marine Models, Comparative Physiology of Erythrocytes, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bouyer
authors.affiliation: Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Moore
authors.affiliation: Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Daley
authors.affiliation: Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hoke
authors.affiliation: Department of Biochemistry and Molecular Biology and Center for Malaria Research, Pennsylvania State University, State College, Pennsylvania 16802, USA.
authors.forename: Lindsey M
authors.initials: LM
authors.lastname: Altenhofen
authors.affiliation: Department of Biochemistry and Molecular Biology and Center for Malaria Research, Pennsylvania State University, State College, Pennsylvania 16802, USA.
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Painter
authors.affiliation: Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville MD 20852, USA.
authors.forename: Jianbing
authors.initials: J
authors.lastname: Mu
authors.affiliation: Nuffield Department of Clinical Laboratory Sciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.
authors.forename: David J P
authors.initials: DJ
authors.lastname: Ferguson
authors.affiliation: Department of Biochemistry and Molecular Biology and Center for Malaria Research, Pennsylvania State University, State College, Pennsylvania 16802, USA.
authors.forename: Manuel
authors.initials: M
authors.lastname: Llinás
authors.affiliation: Research School of Biology, Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Rowena E
authors.initials: RE
authors.lastname: Martin
authors.affiliation: Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA.|Division of Infectious Diseases, Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Fidock
authors.affiliation: Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529, USA.|Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA 94901, USA.
authors.forename: Roland A
authors.initials: RA
authors.lastname: Cooper
authors.affiliation: Institute for Infection and Immunity, St. George's, University of London, London SW17 0RE, UK.
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Krishna
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology; D001692:Biological Transport; D002738:Chloroquine / Q000494:pharmacology*; D004351:Drug Resistance / Q000235:genetics*; D006801:Humans; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics*; D009154:Mutation; D009865:Oocytes / Q000378:metabolism; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000502:physiology*; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics*; D014617:Vacuoles / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D000962:Antimalarials; D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; D002738:Chloroquine