Viral Membrane Fusion and Nucleocapsid Delivery into the Cytoplasm are Distinct Events in Some Flaviviruses
Figure 5
PI(3) kinase activity is required for RNA delivery into the cytoplasm and viral infectivity but not membrane fusion.
Cells were pretreated with 0.1 µM wortmannin for 1 h prior to treatment with JE-VLPs (200 µl at 17 pM) or infection with YFVs (MOI = 1). (A) DIC micrograph of the treated cells showing that wortmannin had no toxic effects although treated cells showed a characteristic increase in the number of intracellular vacuoles (red arrows). JE-VLPs, (B), or YFV, (C), fused normally in Vero cells pretreated with wortmannin, as indicated by the R18 fluorescence dequenching profiles of three representative tracked particles. (D) qRT-PCR assay showing that pretreatment of Vero cells with wortmannin reduced the delivery of YFV nucleocapsid into the cytoplasm by 95% relative to untreated cells. Error bars represent the standard error of the mean (SEM) of three experiments. (E) Plaque assay showing that pretreatment of BHK cells with wortmannin reduced YFV replication and viral plaque formation to background levels. See also Movie S3.