TFIID can be rate limiting in vivo for TATA-containing, but not TATA-lacking, RNA polymerase II promoters.
We have studied the effect of exogenous expression of the basal transcription factor TFIID on the activities of several different TATA-containing and TATA-lacking promoters. Overexpression of TFIID from a transfected plasmid in Drosophila Schneider cells resulted in substantial concentration-dependent increases in expression from a cotransfected minimal TATA-containing promoter. Overexpression of TFIID activated expression from all TATA-containing promoters tested, with the maximum level of activation being inversely proportional to the strength of the promoter. In contrast, expression from TATA-less promoters was not enhanced, and could in fact be reduced, by increased expression of TFIID. Consistent with these findings overexpression of TFIID had opposite effects on Sp1-mediated activation observed from minimal synthetic promoters consisting of Sp1-binding sites and either a TATA box or initiator element. We discuss the significance of these results in terms of the role of TFIID in the initiation of transcription and as a possible regulatory target for expression from TATA-containing promoters, as well as the role TFIID may play in expression from TATA-less promoters.
Colgan
J
J
Department of Biological Sciences, Columbia University, New York, New York 10027.
Manley
J L
JL
D000818:Animals; D015153:Blotting, Western; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000502:physiology*; D012319:RNA Polymerase II / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016385:TATA Box / Q000502:physiology*; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D006360:Heat-Shock Proteins; D011993:Recombinant Fusion Proteins; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D015500:Chloramphenicol O-Acetyltransferase; D012319:RNA Polymerase II; D001616:beta-Galactosidase