title: T antigen repression of SV40 early transcription from two promoters.
abstract: The SV40 early mRNAs encode large (T) and small (t) tumor antigens. During the lytic cycle, the 5' termini of the early mRNAs undergo a shift: shortly after infection only an initiation site downstream from the TATA box is utilized; later an upstream initiation site becomes prominent. Both initiation sites are utilized in an in vitro transcription extract. D2T, a T antigen analog, specifically represses transcription in vitro from both initiation sites, but at different concentrations. Binding of D2T to site I suppresses initiation from the site downstream of the TATA box; binding to sites II and I suppresses initiation from the upstream site. The role of T antigen binding in repression of transcription and in the shift of initiation sites on the early strand is discussed.
mesh_terms: D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D001483:Base Sequence; D004279:DNA, Viral / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012367:RNA, Viral / Q000235:genetics; D013539:Simian virus 40 / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D000952:Antigens, Polyomavirus Transforming; D004279:DNA, Viral; D012367:RNA, Viral