FIG. 10.

Effects of mutations in the Oscar elements on transcription from the ICP4 promoter. Vero cells were transfected with ICP4 promoter-CAT reporter plasmids. After 18 h, the transfected cells were either mock infected or infected with HSV-1 strain KOS at an MOI of 10 PFU/cell to provide viral regulatory proteins in trans. At 4 h p.i., total RNA was extracted from the cells and the levels of CAT RNA message were measured by RNase protection assay. Lanes: 1, full-length CAT antisense riboprobe; 2, no RNA extract; 3 to 14, protected fragments indicating the levels of CAT message transcribed from the ICP4 promoter carrying wild-type or mutant Oscar elements in mock-infected cells (−) or in HSV-infected cells (+).