FIG. 4.

EGFP-VP4 does not localize within identified vesicular compartments. Cos-7 cells were fixed after 24-h pEGFP-VP4-transient transfection, permeabilized, and vesicular compartment markers were stained by indirect immunofluorescence. The major compartments of the exocytic and endocytic pathways were explored using antibodies against protein disulfide isomerase for the endoplasmic reticulum, ERGIC-53 for the intermediate compartment, giantin for the Golgi apparatus, TGN46 protein for the trans-Golgi network, the early endosomal antigen-1 for early endosomes, transferrin receptor for late endosomes, lysotracker for lysosomes, Mitotracker for mitochondria, and either anticatalase antibodies or a dsRed-labeled plasmid containing the peroxisome targeting signal PTS1 for peroxisomes. EGFP-VP4-expressing cells (A′, B′, C′, D′, E′, F′, G′, H′, I′, and J′) were costained with anti-protein disulfide isomerase (PDI) (A”), anti-ERGIC-53 (B"), anti-giantin (C"), anti-TGN-46 (D"), anti-early endosome antigen 1 (E"), anti-transferrin receptor (F"), lysotracker (G"), mitotracker (H"), or anti-catalase (I"). (J′) displays Cos-7 cells cotransfected with plasmids encoding EGFP-VP4 and PST1-dsRed, respectively. Images gallery displays confocal single xy planes. Scale bars = 10 μm.