PfPrex primase traffics to the apicoplast and forms two foci during the intraerythrocytic cycle. The complete primase domain (AA1–465) of PfPrex was genetically fused to GFPmut2 and expressed from a nuclear plasmid in P. falciparum NF54 parasites. Indirect immunofluorescence microscopy with DAPI and antibodies against GFP and PfACP demonstrates clear apicoplast localization of PfPrex throughout the intraerythrocytic cycle. Differential interference contrast (DIC) images show typical appearances of both the parasite and the host RBC. Two foci appear within the apicoplast during the early trophozoite stage and then segregate to daughter merozoites during schizogony. Scale bar is 5 mm.

Lindner SE, Llinás M, Keck JL, Kappe SH. The primase domain of PfPrex is a proteolytically matured, essential enzyme of the apicoplast. Mol Biochem Parasitol. 2011 180(2):69-75