Cell-free translation of RNA synthesized in vitro by a transcribing nucleoprotein complex prepared from purified vesicular stomatitis virus

Abstract

The RNA species synthesized in vitro by a transcribing nucleoprotein (TNP) complex of vesicular stomatitis virus (VSV) were translated with high efficiency in a fractionated cell-free system derived from reticulocytes. The use of TNP complexes isolated from VSV Indiana, VSV New Jersey, and Chandipura viruses showed that in each case the predominant polypeptides synthesized had electrophoretic mobilities identical to their virion N, NS, and M polypeptides in proportions reflecting those found in infected cells rather than purified virions. A minor polypeptide corresponding to unglycosylated polypeptide G was also observed, but the in vitro synthesis of polypeptide L was not detected. The addition of RNase inhibitor to transcription mixtures markedly increased the rate of RNA synthesis. Furthermore, the messenger activity of the RNA was significantly enhanced. The inclusion of S-adenosyl L-methionine during transcription substantially increased the messenger activity of the product RNA, suggesting a requirement for methylation. Fractionation by oligodeoxythymidylic acid-cellulose chromatography revealed that the RNA required a polyadnylic acid tract for messenger activity.