Effect of brefeldin A on the localization of GFP-VP16. Vero cells were infected with HSV-1 v44 at an MOI of 10 and incubated in the presence or absence of brefeldin A at 1 μg/ml. Live infected cells were analyzed at various times thereafter as indicated. While the nuclear pattern of GFP-VP16 was not significantly altered, within the cytoplasm, GFP-VP16 accumulated in larger distributed spherical foci, which did not cluster pericentrically within the cell, in contrast to the vesicular clustering seen in the absence of the drug. Bars, 10 μm.