blasticidin-a and artemisinin

Plasmodium falciparum multidrug resistance constitutes a major obstacle to the global malaria elimination campaign. Specific mutations in the Plasmodium falciparum chloroquine resistance transporter (PfCRT) mediate resistance to the 4-aminoquinoline drug chloroquine and impact parasite susceptibility to several partner agents used in current artemisinin-based combination therapies, including amodiaquine. By examining gene-edited parasites, we report that the ability of the wide-spread Dd2 PfCRT isoform to mediate chloroquine and amodiaquine resistance is substantially reduced by the addition of the PfCRT L272F mutation, which arose under blasticidin selection. We also provide evidence that L272F confers a significant fitness cost to asexual blood stage parasites. Studies with amino acid-restricted media identify this mutant as a methionine auxotroph. Metabolomic analysis also reveals an accumulation of short, hemoglobin-derived peptides in the Dd2 + L272F and Dd2 isoforms, compared with parasites expressing wild-type PfCRT. Physiologic studies with the ionophores monensin and nigericin support an impact of PfCRT isoforms on Ca

Topics: Amodiaquine; Antimalarials; Artemisinins; Calcium; Cells, Cultured; Chloroquine; Drug Resistance, Multiple; Erythrocytes; Gene Expression; Hemoglobins; Host-Parasite Interactions; Humans; Ion Transport; Ionophores; Membrane Transport Proteins; Monensin; Mutation; Nigericin; Plasmodium falciparum; Protozoan Proteins; Pyrrolidinones