The Effect of Interferon on the Synthesis and Activity of an RNA Polymerase Isolated from Chick Cells Infected with Semliki Forest Virus

Abstract

Summary The effect of interferon on the activity and synthesis of a specific Semliki forest virus RNA polymerase has been studied. Highly purified and semipurified interferons were without effect on the action of the viral RNA polymerase in the in vitro assay, while crude interferon preparations were inhibitory. Polymerase activity was low in interferon-treated infected cells, but this did not result from the presence of enzyme inhibitors in the preparations. Attempts to demonstrate an inhibitor of the polymerase in interferon-treated uninfected cells were unsuccessful. The inhibition of viral RNA synthesis observed in interferon-treated cells may result from an inhibition of the synthesis of the viral RNA polymerase rather than from an inhibition of the action of this enzyme.