Eukaryotic activators function during multiple steps of preinitiation complex assembly.
Eukaryotic activator proteins (activators) stimulate transcription by increasing assembly of the preinitiation complex. We have developed methods to quantify the stable assembly of general transcription factors into transcriptional complexes in response to activators. We show that activators function during at least two stages of preinitiation complex assembly: first, to recruit the general transcription factor TFIIB, and then at a second step, after TFIIB entry. It is at this second step that the TATA-box binding protein associated factors act. This step also seems to be critical for activators to stimulate transcription synergistically.
Choy
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B
Program in Molecular Medicine, University of Massachusetts Medical Center, Worcester 01605.
Green
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D002467:Cell Nucleus / Q000378:metabolism; D002850:Chromatography, Gel; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D029701:Saccharomyces cerevisiae Proteins; D016385:TATA Box; D035181:TATA-Box Binding Protein; D013698:Templates, Genetic; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors