Characteristics of the induction of a new protein kinase in cells infected with herpesviruses.

The appearance of a recently described protein kinase activity (virus-induced protein kinase, ViPK) has been studied during infection of hamster fibroblasts with pseudorabies virus or with herpes simplex virus type 1 (HSV-1). An enzyme activity with comparable catalytic properties was induced in both cases, and had broadly similar kinetics of appearance to that of the viral DNA polymerase. The amount of active ViPK detected depended on the multiplicity of infection, and no ViPK was induced after the viruses had been subjected to irradiation with u.v. light. When cells were infected with the tsK mutant of HSV-1, ViPK was induced at the permissive but not at the restrictive temperature. The ViPK preparations obtained from cells infected with each virus differed in chromatographic properties on anion-exchange and gel-permeation resins. These results indicate that expression of the viral genome is required for induction of ViPK. They suggest that the enzyme may be encoded by the viral genome, but do not provide proof of this.