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). B. Parasites co-transfected with PfSec24a-mRFP and GFP-PfSec12 at the trophozoite stage. PfSec24 foci appear closely associated with the nuclear envelope in mature parasites. 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. PMID: 18410493