Variation of DNA polymerase and RNA polymerase activities in cells infected with herpes simplex virus type 1.

Infection of rabbit kidney cells with herpes simplex virus (HSV) leads to pronounced alterations of the different species of DNA-dependent DNA and DNA-dependent RNA polymerases. The activity of distinct polymerase species was determined; it was ruled out first that deoxyribonucleases or ribonucleases had an influence on these determinations and second that the activities of isoenzymes modified the evaluation of the activity of a distinct enzyme species. The three different DNA-dependent DNA polymerases (form a and β and HSV-induced enzyme) were separated by velocity sedimentation through sucrose density gradients and were asscyayed using activated DNA as template. DNA polymerase a and HSV polymerase were resolved by different assay conditions. The cellular polymerase a decreases by 80% 10 hr after infection with HSV, while the cellular polymerase β shows a slight increase during this period. The activity of HSV-induced DNA polymerase at the beginning of infection is virtually zero; it increases to a maximum 8 hr postinfection. The activity of DNA-dependent RNA polymerase I declines dramatically, by 68%, after infection with HSV while the alterations of the activities of RNA polymerases II and III are less pronounced.