Regulation of virus-induced deoxyribonucleases.

Abstract

The control of 3 poxvirus-induced enzymes (thymidine kinase, "alkaline" DNase, and "acid" DNase) involve 3 different mechanisms. FUdR or BUdR blocks the repression of both thymidine kinase which has a stable messenger, and the repression of alkaline DNase which has an unstable messenger. The times at which thymidine kinase synthesis and the increase in alkaline DNase activity are arrested in one ceU- virus system can be clearly distinguished. The mechanism responsible for the termination of the increase in alkaline DNase activity is not dependent on protein synthesis, whereas re pression of thymidine kinase synthesis requires protein synthesis. In contrast to the induction of thymidine kinase or alkaline DNase, the viral induction of acid DNase is completely inhibited by inhibiting viral DNA synthesis with FUdR. The FUdR effect is reversible.