title: Mediator binding to UASs is broadly uncoupled from transcription and cooperative with TFIID recruitment to promoters.
abstract: Mediator is a conserved, essential transcriptional coactivator complex, but its in vivo functions have remained unclear due to conflicting data regarding its genome-wide binding pattern obtained by genome-wide ChIP Here, we used ChEC-seq, a method orthogonal to ChIP, to generate a high-resolution map of Mediator binding to the yeast genome. We find that Mediator associates with upstream activating sequences (UASs) rather than the core promoter or gene body under all conditions tested. Mediator occupancy is surprisingly correlated with transcription levels at only a small fraction of genes. Using the same approach to map TFIID, we find that TFIID is associated with both TFIID- and SAGA-dependent genes and that TFIID and Mediator occupancy is cooperative. Our results clarify Mediator recruitment and binding to the genome, showing that Mediator binding to UASs is widespread, partially uncoupled from transcription, and mediated in part by TFIID.
authors: Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA sgruenbe@fredhutch.org gzentner@indiana.edu.
authors: Sebastian
authors: 0000-0002-5694-0574
authors: S
authors: Grünberg
authors: Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.|Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors: Steven
authors: S
authors: Henikoff
authors: Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors: Steven
authors: S
authors: Hahn
authors: Department of Biology, Indiana University, Bloomington, IN, USA sgruenbe@fredhutch.org gzentner@indiana.edu.
authors: Gabriel E
authors: 0000-0002-0801-7646
authors: GE
authors: Zentner
mesh_terms: D047369:Chromatin Immunoprecipitation; D004271:DNA, Fungal / Q000378:metabolism*; D056892:Mediator Complex / Q000378:metabolism*; D011485:Protein Binding; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D035181:TATA-Box Binding Protein / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D004271:DNA, Fungal; D056892:Mediator Complex; C115017:SPT15 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035181:TATA-Box Binding Protein
keywords: 
  TFIID
  ; ChEC‐seq; Mediator