Inhibition of DNA-primed RNA synthesis during poliovirus infection of human cells

Abstract

It was shown previously that poliovirus infection of HeLa cells leads within several hours to a drastic change in the base ratios of newly-synthesized RNA, and it was suggested that the synthesis of normal cell RNA is inhibited (Holland, 1961). Data in press indicate that most RNA synthesis during polio-virus infection is virus-directed (Holland, 1963a) and that host cell-controlled RNA synthesis is in fact suppressed up to 90% during poliovirus infection (Holland, 1963b). The present report concerns the mechanism by which virus suppresses normal cell RNA synthesis. It will be demonstrated that DNA extracted from infected cells is as capable of priming RNA synthesis with E. coli RNA polymerase as normal cell DNA. Even the “native” deoxyribonucleo-proteins of gently-disrupted normal and infected HeLa cells are equal in priming ability for the E. coli RNA polymerase described by Chamberlin and Berg (1962). However, “aggregate enzyme” (DNA-protein complex containing RNA polymerase [Weiss, 1960]) extracted from infected cells shows only a small fraction of the RNA polymerizing activity of similar preparations extracted from normal cells. Baltimore and Franklin (1962) have recently reported a similar depression of aggregate enzyme activity in Mengo virus infection of mouse cells.