Formation of DENV vesicle packets is independent from the interaction between NS1 and the NS4A-2K-4B precursor.

Huh7-Lunet T7 cells were transfected with the DENV polyprotein expression construct shown in Fig 8A and 18 h later, cells were fixed and processed for transmission electron microscopy. (A) Representative images of membrane invaginations observed in cells transfected with the wildtype (WT) polyprotein, the G161A or the W168A mutant, respectively. Scale bars (upper left of each panel) correspond to 500 nm in the overview and 100 nm in the cropped sections that are indicated with black rectangles in the overviews. (B) Quantification of the number of cells containing VPs. Results show the mean of two independent experiments, counting at least 20 cells per construct and experiment. The error bars indicate SD. Transfection efficiency as determined by immunofluorescence was ~45%. (C) Quantitation of the vesicle diameter in cells transfected with WT, G161A or W168A polyprotein construct. Scatter plots indicate the diameter of >100 vesicles from two independent experiments; horizontal lines indicate means and error bars indicate SD.