Figure 3. Resistance to imidazopyrazine and quinoxaline compounds is mediated by gene variations in PfPI4K and PfRab11A.

a, Fold-change in IC₅₀ values between 11 drug-evolved clones and the drug-sensitive parent, for the imidazopyrazines, KAI407, KAI715, KDU691, and the quinoxaline BQR695 (means±s.d.; n=8). Statistically significant mean IC₅₀ values for each drug-resistant line were identified using the Mann-Whitney U test (also for panels c, d, e). CNVs and SNVs are noted. b, Schematic overview of the pfpi4k gene editing strategy to introduce putative resistance mutations into a wild type parasite. ZFNs target a 34-bp site on pfpi4k (thunderbolt); following cleavage, homology-dependent repair from a 1.7 kb donor sequence resulted in incorporation of the specific SNV (shown in red), as well as additional silent mutations at the ZFN cut site. c, Fold-change in IC₅₀ values of ZFN-edited lines H1484Y-, S1320L-and Y1356F-PfPI4K against KAI407, KDU691, KAI715 and BQR695 (means±s.d.; n=12). IC₅₀ values for other known antimalarials are provided in Extended Data Fig. 5a. d, Chromosomal integration of GFP fusions of wild type Rab11A, mutant Rab11A (D139Y) or wild type PI4K conferred resistance to imidazopyrazine and quinoxaline compounds. A control line expressing GFP alone was used to normalize the IC₅₀ shift (means±s.d.; n=6). e, Fold-change in IC₅₀ values of P. berghei in vitro liver-stage schizonts expressing PbPI4K-H1477Y (equivalent to PfPI4K-H1484Y). Data shown as means±s.d. (n=12).