Figure 6: Phosphorylation of PfCDPK1 at S64 occurs during the schizont (Schiz) stage of parasite development.

(a) Parasite lysates (15 μg) prepared from ring, trophozoite (Troph) or Schiz stage and were probed with the structural PfCDPK1 antibody, the phospho-specific CDPK1-pS64 antibody or the Schiz-specific marker PfEBA-175. (b) A late Schiz culture treated with vehicle or Compound 2 (2μM; 60min) was fixed and probed with DAPI stain to reveal the nuclei (blue), the anti-HA antibody to reveal PfCDPK1-HA expressed in transgenic parasites (red) or the phospho-specific CDPK1-pS64 antibody (green). A merge of images from all three stains is shown as well as a differential interference contrast (DIC) image. (c,d) Free merozoites were fixed and probed with DAPI stain to reveal the nuclei (blue), the anti-HA antibody to reveal PfCDPK1-HA (red) or the phospho-specific CDPK1-pS64 antibody (green). A merge of images from all three stains is shown. (e) A rendered image where deconvoluted z stacks (see; Supplementary Movie 1) were reconstructed in 3D, with interpolation, of wild-type parasites stained with DAPI (blue), the structural CDPK1 antibody to reveal the total pool of PfCDPK1 (red) and the CDPK1-pS64 antibody (green). (f) Same as e but in this case the images (see; Supplementary Movie 2—video for z stacks) are of a free merozoite. These results are representative of at least three experiments. Scale bars, b=1 μm, c=0.5 μm, d=0.5 μm, e=1 μm, f=0.5 μm