Comparison of the polyoma virus early and late promoters by transcription in vitro.
AUTOR(ES)
Jat, P
RESUMO
Polyoma virus DNA was transcribed in the HeLa whole cell extract in vitro system (1). Early region transcripts with the same 5'-ends as in vivo mRNAs, located 31 +/- 2bp from 'TATA'-boxes, were synthesized by RNA polymerase II. Sequences sufficient for efficient expression of the early promoter were present in a substitution mutant lacking viral DNA from a position 55bp before the principal cap sites. Late region transcripts were synthesised inefficiently. Only one (at nt5129 +/- 2) of the many late mRNA cap sites functioned as an in vitro initiation point. This was the one 5'-end located 31 +/- 2bp from a sequence resembling the 'TATA' consensus. The proportion of late to early region RNA polymerase II transcripts decreased dramatically at suboptimal template concentrations. An hypothesis to explain the regulation of late gene expression in vivo based on these results is proposed. A linear templates were transcribed only by RNA polymerase II, transcripts with the same sense as late mRNAs and 5'-ends at nt5076 +/- 2 were produced from superhelical template by an alpha amanitin resistant enzyme.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=326208Documentos Relacionados
- Comparison of phosphorylation of two polyoma virus middle T antigens in vivo and in vitro.
- Initiation and regulation of simian virus 40 early transcription in vitro.
- A Cellular Protein Binds Vaccinia Virus Late Promoters and Activates Transcription In Vitro
- Polyoma virus early-late switch: regulation of late RNA accumulation by DNA replication.
- Transcription from the SV40 early-early and late-early overlapping promoters in the absence of DNA replication.
