TFIIA plays a role in the response to oxidative stress.
To characterize the role of the general transcription factor TFIIA in the regulation of gene expression by RNA polymerase II, we examined the transcriptional profiles of TFIIA mutants of Saccharomyces cerevisiae using DNA microarrays. Whole-genome expression profiles were determined for three different mutants with mutations in the gene coding for the small subunit of TFIIA, TOA2. Depending on the particular mutant strain, approximately 11 to 27% of the expressed genes exhibit altered message levels. A search for common motifs in the upstream regions of the pool of genes decreased in all three mutants yielded the binding site for Yap1, the transcription factor that regulates the response to oxidative stress. Consistent with a TFIIA-Yap1 connection, the TFIIA mutants are unable to grow under conditions that require the oxidative stress response. Underexpression of Yap1-regulated genes in the TFIIA mutant strains is not the result of decreased expression of Yap1 protein, since immunoblot analysis indicates similar amounts of Yap1 in the wild-type and mutant strains. In addition, intracellular localization studies indicate that both the wild-type and mutant strains localize Yap1 indistinguishably in response to oxidative stress. As such, the decrease in transcription of Yap1-dependent genes in the TFIIA mutant strains appears to reflect a compromised interaction between Yap1 and TFIIA. This hypothesis is supported by the observations that Yap1 and TFIIA interact both in vivo and in vitro. Taken together, these studies demonstrate a dependence of Yap1 on TFIIA function and highlight a new role for TFIIA in the cellular mechanism of defense against reactive oxygen species.
Kraemer
Susan M
SM
Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, USA.
Goldstrohm
David A
DA
Berger
Ann
A
Hankey
Susan
S
Rovinsky
Sherry A
SA
Scott Moye-Rowley
W
W
Stargell
Laurie A
LA
D000595:Amino Acid Sequence; D002467:Cell Nucleus; D016000:Cluster Analysis; D015342:DNA Probes; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D018384:Oxidative Stress / Q000502:physiology*; D010641:Phenotype; D011485:Protein Binding; D017382:Reactive Oxygen Species / Q000009:adverse effects; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D035561:Transcription Factor TFIIA / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism
D015342:DNA Probes; D017382:Reactive Oxygen Species; D029701:Saccharomyces cerevisiae Proteins; D035561:Transcription Factor TFIIA; D014157:Transcription Factors; C086677:YAP1 protein, S cerevisiae