title: Malaria drug resistance is associated with defective DNA mismatch repair.
abstract: Malarial parasites exhibit striking genetic plasticity, a hallmark of which is an ever-increasing rate of resistance to new drugs, especially in Southeast Asia where multi-drug resistance (MDR) threatens the last line of antimalarial drugs, the artesunate compounds. Previous studies quantified the accelerated resistance to multiple drugs (ARMD) phenomenon, but the underpinning mechanism(s) remains unknown. We utilize a forward genetic assay to investigate a new hypothesis that defective DNA mismatch repair (MMR) contributes to the development of MDR by Plasmodium falciparum parasites. We report that two ARMD parasites, W2 and Dd2, have defective MMR, as do the chloroquine-resistant parasites T9-94, 7C12, and 7G8. By contrast, the chloroquine-sensitive parasites HB3, D6 and 3D7 were MMR proficient. Interestingly, W2 was unable to repair substrates with a strand break located 3' to the mismatch, which is attributable to a large observed decrease in PfMutLα content. These data imply that antimalarial drug resistance can result from defective MMR.
authors.affiliation: Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
authors.forename: Meryl A
authors.initials: MA
authors.lastname: Castellini
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Buguliskis
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Casta
authors.forename: Charles E
authors.initials: CE
authors.lastname: Butz
authors.forename: Alan B
authors.initials: AB
authors.lastname: Clark
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Kunkel
authors.forename: Theodore F
authors.initials: TF
authors.lastname: Taraschi
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D053843:DNA Mismatch Repair; D049914:DNA Repair-Deficiency Disorders; D004351:Drug Resistance; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics
chemical_list: D000962:Antimalarials