FIG. 6.

Internalization of VP16-GFP in 14R-VP16G- and 14D-VP16G-infected cells. Vero cells were synchronously infected with the two strains at an MOI of 50 PFU/cell in the presence of cycloheximide. Immediately after adsorption, cells were fixed to visualize bound virus (A and E) or treated with 2 mg/ml proteinase K for 1 h either immediately (B and F) or following 30 min (C and G) or 1 h (D and H) of incubation at 37°C. Treated cells were fixed thereafter to examine internalized VP16-GFP. 14R-VP16G and 14D-VP16G did not exhibit a marked difference in internalization or in total GFP fluorescence. 14R-VP16G-infected cells exhibited VP16-GFP nuclear localization (arrows in panel D), whereas 14D-VP16G-infected cells did not (H). This suggested that UL14 protein was important for the dispersal and/or nuclear targeting of VP16-GFP. Bars, 10 μm.