title: The molecular basis of antifolate resistance in Plasmodium falciparum: looking beyond point mutations.
abstract: Drugs that target the folate-synthesis pathway have a long history of effectiveness against a variety of pathogens. As antimalarials, the antifolates were safe and well tolerated, but resistance emerged quickly and has persisted even with decreased drug pressure. The primary determinants of resistance in Plasmodium falciparum are well-described point mutations in the enzymes dihydropteroate synthase and dihydrofolate reductase targeted by the combination sulfadoxine-pyrimethamine. Recent work has highlighted the contributions of additional parasite adaptation to antifolate resistance. In fact, the evolution of antifolate-resistant parasites is multifaceted and complex. Gene amplification of the first enzyme in the parasite folate synthesis pathway, GTP-cyclohydrolase, is strongly associated with resistant parasites and potentially contributes to persistence of resistant parasites. Further understanding of how parasites adjust flux through the folate pathway is important to the further development of alternative agents targeting this crucial synthesis pathway.
authors.affiliation: Department of Microbiology and Immunology.
authors.forename: Adina
authors.initials: A
authors.lastname: Heinberg
authors.forename: Laura
authors.initials: L
authors.lastname: Kirkman
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000494:pharmacology / Q000627:therapeutic use*; D004351:Drug Resistance / Q000187:drug effects / Q000235:genetics*; D005493:Folic Acid Antagonists / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D010963:Plasmodium falciparum / Q000187:drug effects / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics*; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics
chemical_list: D000962:Antimalarials; D005493:Folic Acid Antagonists; D013762:Tetrahydrofolate Dehydrogenase
keywords: GTP-cyclohydrolase (GCH1); Plasmodium falciparum; antifolates; malaria; pyrimethamine; sulfadoxine