Expression, export, and localization of GEXP02. (B) Live fluorescence microscopy of all gametocyte stages as well as trophozoite and schizont stages of the 3D7GDV1/GEXP02-tdTomato parasite line. First column shows differential interference contrast (DIC); second column shows tdTomato fluorescence; third column shows nuclei stained with Hoechst; fourth column shows an overlay of all fluorescence channels; fifth column shows a merge with all images (scale bar = 5 μm). Live fluorescence microscopy revealed that GEXP02-tdTomato localizes to the periphery of the GIE in all five gametocyte stages (C) IFAs of all five gametocyte stages of 3D7GDV1/GEXP02-HA parasites. The first column represents the differential interference contrast (DIC) image, the second column shows anti-HA signal labeling GEXP02-HA, the third column shows anti-Pfs16 staining, the fourth column depicts a fluorescence overlay and the fifth column is a merge of all images. All stages were imaged with the same microscope setting, but because the anti-HA signal in gametocyte stages IV and V was weaker the signal was digitally increased post-acquisition to improve its visibility (scale bar = 5 μm). Antibodies against Pfs16, a gametocyte-specific protein localizing to the parasitophorous vacuolar membrane (PVM) were used to confirm that GEXP02-HA was exported into the RBC in sexual stages. (E) Immuno-electron micrograph of negatively stained ultrathin sections of 3D7GDV1/GEXP02-HA. GEXP02 was probed with anti-HA (5 nm gold, indicated by arrows) and Pfs16 with anti-Pfs16 (10 nm gold). PVM: parasitophorous vacuole membrane, GIE: gametocyte-infected erythrocyte (white scale bar = 1 μm, black scale bar = 200 nm). GEXP02-HAwas decorated with 5 nm gold particles and found to be evenly distributed underneath the entire GIE membrane, while Pfs16 was decorated with 10 nm gold particles at the PVM.

Warncke JD, Passecker A, Kipfer E, Brand F, Pérez-Martínez L, Proellochs NI, Kooij TWA, Butter F, Voss TS, Beck HP. The PHIST Protein GEXP02 Targets the Host Cytoskeleton During Sexual Development of Plasmodium falciparum. Cell Microbiol. 2019 Oct 25:e13123. PMID:31652487