Function and Regulation of RNA Polymerases II and III in Adenovirus-infected KB Cells

Abstract

INTRODUCTION
The lytic infection of human cells with adenovirus 2 provides a useful system for analysis of RNA synthesis in mammalian cells since many features of viral RNA synthesis, processing and transport are similar to the respective cellular processes (reviewed in Green et al. 1970; Philipson et al. 1975). During the early phase of viral infection, only a limited portion of the viral genome is transcribed into mRNA. In contrast, after the onset of viral DNA replication, the viral mRNAs are derived from a much larger fraction of the genome (Green et al. 1970; Lucas and Ginsberg 1971; Sharp, Gallimore and Flint 1975; Philipson et al. 1975; Craig and Raskas 1975). During both early and late periods of infection, some viral RNA sequences present within the nucleus are not present in cytoplasmic viral RNA, suggesting the existence of nuclear precursors to the cytoplasmic viral mRNAs (Wall, Philipson and Darnell 1972; Lucas and Ginsberg 1972; Philipson et al. 1975; Sharp, Gallimore and Flint 1975; Craig et al. 1975). In addition to the synthesis of viral mRNA, a low molecular weight viral RNA (5.5S RNA) is synthesized in large amounts late in infection (Ohe, Weissman and Cooke 1969; Ohe 1972). Although the function of this RNA is unknown, its sequence has been determined (Ohe and Weissman 1971). The appearance of the two classes of late viral mRNAs coincides with a dramatic increase in the rate of total cellular RNA (host plus viral) synthesis (Pina and Green 1969). This change appears to result...