Mot1-mediated control of transcription complex assembly and activity.
Mot1 is an essential Snf2/Swi2-related ATPase and TATA-binding protein (TBP)-associated factor (TAF). In vitro, Mot1 utilizes ATP hydrolysis to disrupt TBP-DNA complexes, but the relationship of this activity to Mot1's in vivo function is unclear. Chromatin immunoprecipitation was used to determine how Mot1 affects the assembly of preinitiation complexes (PICs) at Mot1-controlled promoters in vivo. We find that the Mot1-repressed HSP26 and INO1 promoters are both regulated by TBP recruitment; inactivation of Mot1 leads to increased PIC formation coincident with derepression of transcription. For the Mot1-activated genes BNA1 and URA1, inactivation of Mot1 also leads, remarkably, to increased TBP binding to the promoters, despite the fact that transcription of these genes is obliterated in mot1 cells. In contrast, levels of Taf1, TFIIB, and RNA polymerase II are reduced at Mot1-activated promoters in mot1 cells. These results suggest that Mot1-mediated displacement of TBP underlies its mechanism of repression and activation at these genes. We suggest that at activated promoters, Mot1 disassembles transcriptionally inactive TBP, thereby facilitating the formation of a TBP complex that supports functional PIC assembly.
Dasgupta
Arindam
A
Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908-0733, USA.
Juedes
Sarah A
SA
Sprouse
Rebekka O
RO
Auble
David T
DT
D000251:Adenosine Triphosphatases; D051792:Basic Helix-Loop-Helix Proteins; D047369:Chromatin Immunoprecipitation; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D006360:Heat-Shock Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012331:RNA, Fungal / Q000378:metabolism; D012097:Repressor Proteins / Q000037:antagonists & inhibitors; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics / Q000378:metabolism*; D035181:TATA-Box Binding Protein / Q000378:metabolism*; D014157:Transcription Factors / Q000037:antagonists & inhibitors; D014158:Transcription, Genetic
D000251:Adenosine Triphosphatases; D051792:Basic Helix-Loop-Helix Proteins; D004265:DNA Helicases; D006360:Heat-Shock Proteins; D012331:RNA, Fungal; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D014157:Transcription Factors; C499528:HSP26 protein, S cerevisiae; C095723:INO2 protein, S cerevisiae; C073676:MOT1 protein, S cerevisiae