FIG. 6.

Effect of a MEK inhibitor, UO126, on CAT expression from the UL4-CAT promoter in recombinant virus-infected HFFs. Confluent HFFs were serum starved for 24 h and then treated with UO126 for 1 h before infection with recombinant viruses in the presence of UO126 in quadruplicate as described in Materials and Methods. Cells were harvested at 8 h after infection and subjected to CAT assays. The results of the CAT assays were averaged, and the standard deviations were calculated. The CAT activity per microgram of protein at various concentrations of the drug is relative to that of the nontreated recombinant viruses.