Functional association between the B5M12 locus and mutant PfCRT in conferring quinine and quinidine response variations. A. Live cell images of the P. falciparum strains indicated expressing an episomal copy of the Dd2 form of pfcrt fused to the GFP coding sequence. Fluorescence is located at the digestive vacuolar membrane, consistent with previous reports [69]. Bar, 2 mM. The copy number of the plasmid per haploid genome is indicated. The means 6 SEM of at least 6 biological replicates are shown. The copy numbers are not statistically different in the transfectants. we selected three progeny (GC03, CH3-116 and C188) that harbor the wild type pfcrt allele but which differ with regard to the B5M12 locus. GC03 contains the wild type HB3 B5M12 variant, whereas CH3-116 and C188 inherited the B5M12 locus from Dd2 (Table 1). The three progeny and the two parental clones HB3 and Dd2 were transfected with a vector expressing the Dd2 pfcrt variant fused in frame with the coding sequence of the green fluorescence protein. In all cases, the PfCRT/GFP fusion protein was expressed and localized at the membrane of the parasite’s digestive vacuole, as determined by live cell fluorescence microscopy.

Sanchez CP, Liu CH, Mayer S, Nurhasanah A, Cyrklaff M, Mu J, Ferdig MT, Stein WD, Lanzer M. A HECT ubiquitin-protein ligase as a novel candidate gene for altered quinine and quinidine responses in Plasmodium falciparum. PLoS Genet. 2014 10(5):e1004382.