Assembly of recombinant TFIID reveals differential coactivator requirements for distinct transcriptional activators.
We previously reported that transcriptional regulators can bind selected TAF subunits of the TFIID complex. However, the specificity and function of individual TAFs in mediating transcriptional activation remained unknown. Here we report the in vitro assembly and transcriptional properties of TBP-TAF complexes reconstituted from the nine recombinant subunits of Drosophila TFIID. A minimal complex containing TBP and TAFII250 directs basal but not activator-responsive transcription. By contrast, reconstituted holo-TFIID supports activation by an assortment of activators. The activator NTF-1, which binds TAFII150, stimulates transcription with a complex containing only TBP, TAFII250, and TAFII150, whereas Sp1 binds and additionally requires TAFII110 for activation. Interestingly, TAFII150 enhances Sp1 activation even though this subunit does not bind directly to Sp1. These results establish that specific subcomplexes of TFIID can mediate activation by different classes of activators and suggest that TAFs perform multiple functions during activation.
Chen
J L
JL
Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720-3202.
Attardi
L D
LD
Verrijzer
C P
CP
Yokomori
K
K
Tjian
R
R
D000595:Amino Acid Sequence; D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins; D051548:Histone Acetyltransferases; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000096:biosynthesis*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D016385:TATA Box; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000096:biosynthesis* / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D016329:Sp1 Transcription Factor; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; C087177:Taf2 protein, Drosophila; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D051548:Histone Acetyltransferases; C069001:TATA-binding protein associated factor 250 kDa