Characterization of an intermediate compartment in PfEMP1 export. (A) Transfectants (ITK strain) expressing the PfEMP1B-GFP chimera were co-labeled with BODIPY-ceramide and imaged using 3D-SIM. See higher magnification image at right. (B) PfEMP1B-GFP transfectants (endogenous GFP fluorescence; green) were permeabilized with EqtII and antibody-accessible epitopes were labeled with anti-GFP (magenta) and anti-REX1 (red). (C) PfEMP1B-GFP transfectants were fixed and resin-embedded and sections were labeled with anti-GFP and protein-A-gold (6 nm left panels, 10 nm right panels). Labeling is observed at bulges in the PV (arrows). (D) Smears of PfEMP1B-GFP transfectant-infected RBCs were fixed with acetone: methanol and stained with antibodies recognizing GFP and Exp1 (D) or Hsp101 (E). Scale bars = 2 μm (A, first three columns), 1 μm (A, last column), 2 μm (B), as marked (C) and 2 μm (D, E).

McMillan PJ, Millet C, Batinovic S, Maiorca M, Hanssen E, Kenny S, Muhle RA, Melcher M, Fidock DA, Smith JD, Dixon MW, Tilley L. Spatial and temporal mapping of the PfEMP1 export pathway in Plasmodium falciparum. Cell Microbiol. 15(8):1401-18