title: Expression in yeast links field polymorphisms in PfATP6 to in vitro artemisinin resistance and identifies new inhibitor classes.
abstract: BACKGROUND
  The mechanism of action of artemisinins against malaria is unclear, despite their widespread use in combination therapies and the emergence of resistance.
  
  
  RESULTS
  Here, we report expression of PfATP6 (a SERCA pump) in yeast and demonstrate its inhibition by artemisinins. Mutations in PfATP6 identified in field isolates (such as S769N) and in laboratory clones (such as L263E) decrease susceptibility to artemisinins, whereas they increase susceptibility to unrelated inhibitors such as cyclopiazonic acid. As predicted from the yeast model, Plasmodium falciparum with the L263E mutation is also more susceptible to cyclopiazonic acid. An inability to knockout parasite SERCA pumps provides genetic evidence that they are essential in asexual stages of development. Thaperoxides are a new class of potent antimalarial designed to act by inhibiting PfATP6. Results in yeast confirm this inhibition.
  
  
  CONCLUSIONS
  The identification of inhibitors effective against mutated PfATP6 suggests ways in which artemisinin resistance may be overcome.
authors.affiliation: Division of Clinical Sciences, St. George's, University of London, UK.
authors.forename: Serena
authors.initials: S
authors.lastname: Pulcini
authors.forename: Henry M
authors.initials: HM
authors.lastname: Staines
authors.forename: Jon K
authors.initials: JK
authors.lastname: Pittman
authors.forename: Ksenija
authors.initials: K
authors.lastname: Slavic
authors.forename: Christian
authors.initials: C
authors.lastname: Doerig
authors.forename: Jean
authors.initials: J
authors.lastname: Halbert
authors.forename: Rita
authors.initials: R
authors.lastname: Tewari
authors.forename: Falgun
authors.initials: F
authors.lastname: Shah
authors.forename: Mitchell A
authors.initials: MA
authors.lastname: Avery
authors.forename: Richard K
authors.initials: RK
authors.lastname: Haynes
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Krishna
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D037621:Artemisinins / Q000494:pharmacology*; D000252:Calcium-Transporting ATPases / Q000235:genetics*; D004351:Drug Resistance; D015870:Gene Expression; D006801:Humans; D021261:Parasitic Sensitivity Tests / Q000379:methods; D010963:Plasmodium falciparum / Q000235:genetics*; D011110:Polymorphism, Genetic; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics
chemical_list: C513500:ATP6 protein, Plasmodium falciparum; D000962:Antimalarials; D037621:Artemisinins; C031327:artemisinin; D000252:Calcium-Transporting ATPases
keywords: Artemisinins; PfATP6; Plasmodium falciparum; cyclopiazonic acid; desferioxamine; drug resistance; malaria; thaperoxides; yeast