Deoxythymidine kinases in varicella-zoster virus infected and biochemically transformed cells

Deoxythymidine kinase (TK) activity induced in varicella-zoster virus (VZV)-infected human embryonic fibroblast (HEF) cells was immunologically distinguishable from that in non infected HEF cells and also from that in herpes simplex virus type 1 (HSV-1) infected HEF cells. The TKs in VZV-biochemically transformed cells were immunologically the same as that induced in VZV-infected human cells and immunologically different from that in Ltk- cells or in HSV-biochemically transformed cells. One peak of TK activity with an Rm value of 0.8-0.9, corresponding to mitochondrial TK, was observed on polyacrylamide gel electrophoresis of Ltk- cell extracts. VZV infected Ltk- cells had two peaks of TK activity with Rm values of 0.45-0.5 (peak I) and 0.8-0.9 (peak II). Peak I and II were concluded to be virus-specific TK and mitochondrial TK, respectively. VZV-biochemically transformed cells had a peak of activity with an Rm value of 0.4-0.5, corresponding to peak I in VZV-infected Ltk- cells; that is VZV-specific TK activity. The present study indicates that VZV has a gene coding for its own TK.