BINDING-SITES FOR THE HERPES-SIMPLEX VIRUS IMMEDIATE-EARLY PROTEIN ICP4 IMPOSE AN INCREASED DEPENDENCE ON VIRAL-DNA REPLICATION ON SIMPLE-MODEL PROMOTERS LOCATED IN THE VIRAL GENOME

We examined the ability of binding sites for the herpes simplex virus immediate-early protein ICP4 to alter the regulation of closely linked promoters by placing strong ICP4 binding sites upstream or downstream of simple TATA promoters in the intact viral genome. We found that bi nding sites strongly reduced the levels of expression at early times p ostinfection and that this effect was partially overcome after the ons et of viral DNA replication. These data confirm that DNA-bound ICP4 ca n inhibit the activity of a closely linked promoter and raise the poss ibility that ICP4 binding sites contribute to temporal regulation duri ng infection.