title: Stimulation of in vitro transcription from the SV40 early promoter by the enhancer involves a specific trans-acting factor.
abstract: A nuclear extract prepared from HeLa cells has been used to study in vitro the transcription of the SV40 early promoter. The deletion of the enhancer results in a strong decrease of transcription, with spermidine and MgCl2 being critical variables in the transcription reactions. Furthermore a competition assay indicates that the stimulation by the enhancer is due to a specific trans-acting factor(s) which acts on it. This factor appears not to interact with SV40 or adenovirus-2 major late upstream (distal) promoter sequences, and its ability to bind to the enhancer is diminished by mutations known to decrease enhancer function in vivo and in vitro.
mesh_terms: D004742:Enhancer Elements, Genetic; D005809:Genes, Regulator; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride; D009154:Mutation; D009876:Operon; D013539:Simian virus 40 / Q000235:genetics*; D013095:Spermidine / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D015636:Magnesium Chloride; D008274:Magnesium; D013095:Spermidine