Right: Live cell imaging of parasites expressing PfSec24-GFP (PF13_0324), with nuclei stained with Hoechst 33342. PfSec24a marks distinct foci that likely represent transitional ER sites that are enriched in the COPII vesicle machinery. Parasites at the ring (row 1), trophozoite (row 2), early schizont (row 3) and late schizont (row 4) stages, as well as released merozoites (row 5) are shown. Bar = 5 µMLeft: Close apposition of PfSec24a-marked tER sites and Golgi. Parasites expressing PfSec24a–mRFP and PfGRASP–GFP demonstrate a close relationship between the number and location of tER sites and Golgi, as illustrated in three representative parasites.Lee MC, Moura PA, Miller EA, Fidock DA. Plasmodium falciparum Sec24 marks transitional ER that exports a model cargo via a diacidic motif. Mol Microbiol. 2008 68:1535-46.

Brefeldin A (BFA) treatment causes retention of GFP-Sys1 at tER sites in an export signal dependent manner. Parasites coexpressing either GFP-Sys1DxE (WT) or GFP-Sys1AxA (AxA) with (A) mRFP-PfSec12 (from the calmodulin 5′ UTR) or (B) PfSec24a-mRFP were treated with 5 μg ml-1 BFA for 16 h prior to imaging. A merged image of a mock-treated control is shown for comparison. ER-retained GFP-Sys1AxA colocalized with PfSec12 throughout the ER (A), whereas GFP-Sys1DxE was enriched at tER sites coincident with PfSec24a (B). Bar = 5 μm.Lee MC, Moura PA, Miller EA, Fidock DA. Plasmodium falciparum Sec24 marks transitional ER that exports a model cargo via a diacidic motif. Mol Microbiol. 2008 68(6):1535-46. PMID:

Brefeldin A (BFA) treatment causes retention of GFP-Sys1 at tER sites in an export signal dependent manner. Parasites coexpressing either GFP-Sys1DxE (WT) or GFP-Sys1AxA (AxA) with (A) mRFP-PfSec12 (from the calmodulin 5′ UTR) or (B) PfSec24a-mRFP were treated with 5 μg ml-1 BFA for 16 h prior to imaging. A merged image of a mock-treated control is shown for comparison. ER-retained GFP-Sys1AxA colocalized with PfSec12 throughout the ER (A), whereas GFP-Sys1DxE was enriched at tER sites coincident with PfSec24a (B). Bar = 5 μm.Lee MC, Moura PA, Miller EA, Fidock DA. Plasmodium falciparum Sec24 marks transitional ER that exports a model cargo via a diacidic motif. Mol Microbiol. 2008 68(6):1535-46.

Left Panel: Live cell imaging of parasites expressing PfSec24-GFP (PF13_0324), with nuclei stained with Hoechst 33342. PfSec24a marks distinct foci that likely represent transitional ER sites that are enriched in the COPII vesicle machinery. Parasites at the ring (row 1), trophozoite (row 2), early schizont (row 3) and late schizont (row 4) stages, as well as released merozoites (row 5) are shown. Bar = 5 µM. Right panel: Close apposition of PfSec24a-marked tER sites and Golgi. Parasites expressing PfSec24a–mRFP and PfGRASP–GFP demonstrate a close relationship between the number and location of tER sites and Golgi, as illustrated in three representative parasites.Lee MC, Moura PA, Miller EA, Fidock DA. Plasmodium falciparum Sec24 marks transitional ER that exports a model cargo via a diacidic motif. Mol Microbiol. 2008 68:1535-46.

Close apposition of PfSec24a-marked tER sites and Golgi. Parasites expressing PfSec24a-mRFP and PfGRASP-GFP demonstrate a close relationship between the number and location of tER sites and Golgi, as illustrated in three representative parasites. Occasionally, two tER foci can be observed adjacent to a single Golgi spot (arrow in bottom row). Bar = 5 μm.Lee MC, Moura PA, Miller EA, Fidock DA. Plasmodium falciparum Sec24 marks transitional ER that exports a model cargo via a diacidic motif. Mol Microbiol. 2008 68(6):1535-46.

The parasite COPII protein PfSec24a labels discrete tER sites.A. PfSec24a-GFP marks 1-2 foci in ring stages (first row) and 2-3 foci in trophozoite stages (second row, parasites labelled `P' in a doubly infected erythrocyte). Proliferation of tER sites accompanied the onset of nuclear division in early schizonts (third row). Late in the intraerythrocytic cycle, however, only a single spot of PfSec24a-GFP is associated with each nucleus in late schizonts (fourth row). Similarly, released merozoites typically possess a single spot of PfSec24-GFP fluorescence (fifth row).Lee MC, Moura PA, Miller EA, Fidock DA. Plasmodium falciparum Sec24 marks transitional ER that exports a model cargo via a diacidic motif. Mol Microbiol. 2008 68(6):1535-46.