PfCK1 immunofluorescence assay on wild-type parasites and transgenic parasites expressing a GFP-tagged PfCK1. (A) 3D7 parasites were examined by immunofluorescence using an anti-PfCK1 serum labelled with rhodamine. DAPI was used to stain the nucleus and the scale bar represents 10 μm. A pre-immune serum used as a negative control did not yield any signal (not shown). (B) An erythrocyte culture infected with synchronised parasites expressing GFP-tagged PfCK1 from the endogenous locus was examined by immunofluorescence using an anti-GFP antibody. DAPI was used to stain the nucleus the scale bar represents 10 μm. As a negative control wild-type 3D7 parasites stained with the same anti-GFP antibody and did not yield any signal (not shown). A pool of CKI is exported to the host erythrocyte periphery at the early stage of infection, and subsequently detectable mostly within the parasite in late trophozoites and schizonts.

Dorin-Semblat D, Demarta-Gatsi C, Hamelin R, Armand F, Carvalho TG, Moniatte M, Doerig C. Malaria Parasite-Infected Erythrocytes Secrete PfCK1, the Plasmodium Homologue of the Pleiotropic Protein Kinase Casein Kinase 1. PLoS One. 2015 10(12):e0139591.