TFIIA has activator-dependent and core promoter functions in vivo.
The physiological role of TFIIA was investigated by analyzing transcription in a yeast strain that contains a TATA-binding protein (TBP) mutant (N2-1) defective for interacting with TFIIA. In cells containing N2-1, transcription from a set of artificial his3 promoters dependent on different activators is generally reduced by a similar extent, indicating that TFIIA function is largely nonselective for activators. In addition, TATA element utilization, a core promoter function, is altered at his3 promoters dependent on weak activators. Genomic expression analysis reveals that 3% of the genes are preferentially affected by a factor of 4 or more. Chimeras of affected promoters indicate that the sensitivity to the TFIIA-TBP interaction can map either to the upstream or core promoter region. Unlike wild-type TBP or TFIIA, the N2-1 derivative does not activate transcription when artificially recruited to the promoter via a heterologous DNA binding domain, indicating that TFIIA is important for transcription even in the absence of an activation domain. Taken together, these results suggest that TFIIA plays an important role in both activator-dependent and core promoter functions in vivo. Further, they suggest that TFIIA function may not be strictly related to the recruitment of TBP to promoters but may also involve a step after TBP recruitment.
Stargell
L A
LA
Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA.
Moqtaderi
Z
Z
Dorris
D R
DR
Ogg
R C
RC
Struhl
K
K
D001426:Bacterial Proteins / Q000235:genetics; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D005800:Genes, Fungal; D006836:Hydro-Lyases / Q000235:genetics; D007700:Kinetics; D009154:Mutation; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases / Q000235:genetics; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D015003:Yeasts / Q000235:genetics*; D000099160:LexA Repressor Protein
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D006836:Hydro-Lyases; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D014157:Transcription Factors; D000099160:LexA Repressor Protein; C052130:GAL4 protein, S cerevisiae; C021434:imidazoleglycerolphosphate dehydratase