141a] RNA polymerase in animal cells infected with RNA viruses

Abstract

Publisher Summary This chapter investigates RNA polymerases in animal cells infected with RNA viruses. Enzymatic activity, which resulted in conversion of 5′-ribonucleoside triphosphates into acidinsoluble form and could be indirectly shown to be dependent on a RNA template, was first demonstrated in L cells infected with mengovirus—a member of the picornavirus group. The production of this enzymatic activity in animal cells is under the control of the virus. There are probably two enzymes controlling viral RNA replication, and strict dependence of enzymatic activity on added viral RNA has been reported. Although the nature of the enzyme or enzymes involved is not clear, at least one is genetically determined by the viral genome. The enzyme activity is merely a crude extract. In general, one should first investigate the site of viral RNA synthesis and then make a crude extract using cell fractionation procedures. The chapter discusses the procedure used for mengovirus-infected L cells. The DNA-dependent RNA polymerase acts as an RNA-dependent enzyme under certain conditions of in vitro assay. Such factors must be taken into account when looking for bona fide RNA-dependent RNA polymerase activity in cells infected with RNA viruses, especially in the crude extracts.