RNA synthesis precision is regulated by preinitiation complex turnover.
TATA-binding protein (TBP) nucleates the assembly of the transcription preinitiation complex (PIC), and although TBP can bind promoters with high stability in vitro, recent results establish that virtually the entire TBP population is highly dynamic in yeast nuclei in vivo. This dynamic behavior is surprising in light of models that posit that a stable TBP-containing scaffold facilitates transcription reinitiation at active promoters. The dynamic behavior of TBP is a consequence of the enzymatic activity of the essential Snf2/Swi2 ATPase Mot1, suggesting that ensuring a highly mobile TBP population is critical for transcriptional regulation on a global scale. Here high-resolution tiling arrays were used to define how perturbed TBP dynamics impact the precision of RNA synthesis in Saccharomyces cerevisiae. We find that Mot1 plays a broad role in establishing the precision and efficiency of RNA synthesis: In mot1-42 cells, RNA length changes were observed for 713 genes, about twice the number observed in set2Δ cells, which display a previously reported propensity for spurious initiation within open reading frames. Loss of Mot1 led to both aberrant transcription initiation and termination, with prematurely terminated transcripts representing the largest class of events. Genetic and genomic analyses support the conclusion that these effects on RNA length are mechanistically tied to dynamic TBP occupancies at certain types of promoters. These results suggest a new model whereby dynamic disassembly of the PIC can influence productive RNA synthesis.
Poorey
Kunal
K
Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908, USA.
Sprouse
Rebekka O
RO
Wells
Melissa N
MN
Viswanathan
Ramya
R
Bekiranov
Stefan
S
Auble
David T
DT
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D047369:Chromatin Immunoprecipitation; D020869:Gene Expression Profiling; D008957:Models, Genetic; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic / Q000235:genetics; D012313:RNA / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics / Q000378:metabolism*; D035181:TATA-Box Binding Protein / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics*
D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D012313:RNA; D000251:Adenosine Triphosphatases; C073676:MOT1 protein, S cerevisiae