Cellular stress alters the transcriptional properties of promoter-bound Mot1-TBP complexes.
Mot1 associates with transcriptionally active promoters, and it directly affects transcriptional activity in a positive or negative manner, depending on the gene. As determined by sequential chromatin immunoprecipitation, Mot1 co-occupies promoters with TBP, but not with TFIIB, TFIIA, or Pol II when cells are grown in normal conditions. This strongly suggests that the Mot1-TBP complex is transcriptionally inactive, and hence is in dynamic equilibrium with transcriptionally active forms of TBP. Surprisingly, in response to heat shock and other forms of environmental stress, Mot1 co-occupies promoters with TFIIB and elongation-competent Pol II, but not with TFIIA. This suggests that functional preinitiation complexes can contain Mot1 instead of TFIIA in vivo. Thus, Mot1-TBP complexes can exist in active and inactive forms that are regulated by environmental stress.
Geisberg
Joseph V
JV
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
Struhl
Kevin
K
D000251:Adenosine Triphosphatases; D003300:Copper / Q000494:pharmacology; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism; D005809:Genes, Regulator / Q000235:genetics*; D018869:Heat-Shock Response / Q000235:genetics; D006982:Hypertonic Solutions / Q000494:pharmacology; D007700:Kinetics; D046911:Macromolecular Substances; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics* / Q000378:metabolism; D035181:TATA-Box Binding Protein / Q000235:genetics* / Q000378:metabolism; D035561:Transcription Factor TFIIA / Q000235:genetics / Q000378:metabolism; D035581:Transcription Factor TFIIB / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation / Q000235:genetics
D006982:Hypertonic Solutions; D046911:Macromolecular Substances; C073680:SUA7 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D035561:Transcription Factor TFIIA; D035581:Transcription Factor TFIIB; D003300:Copper; D012319:RNA Polymerase II; D000251:Adenosine Triphosphatases; C073676:MOT1 protein, S cerevisiae; D004265:DNA Helicases