Transcription of the SV40 Genome in Virus-transformed Cells and Early Lytic Infection

Two proteins, designated large and small T antigens, have been identified as primary translational products of the early region of the SV40 genome. In lytic infection by this virus, large T antigen is essential for initiation of viral (Tegtmeyer 1972; Cowan et al. 1973; Brandner and Mueller 1974; Chou et al. 1974) and host (Chou and Martin 1975) DNA replication. Large T antigen also inhibits synthesis of early mRNA; thus it "autoregulates " its own intracellular level (Tegtmeyer 1975a; Tegtmeyer et al. 1975; Reed et ai. 1976; Khoury and May 1977). Furthermore, by means of its control over viral DNA replication, large T antigen plays an important role in regulating late mRNA and protein