title: Distinct role of Mediator tail module in regulation of SAGA-dependent, TATA-containing genes in yeast.
abstract: The evolutionarily conserved Mediator complex is required for transcription of nearly all RNA Pol II-dependent promoters, with the tail module serving to recruit Mediator to active promoters in current models. However, transcriptional dependence on tail module subunits varies in a gene-specific manner, and the generality of the tail module requirement for transcriptional activation has not been explored. Here, we show that tail module subunits function redundantly to recruit Mediator to promoters in yeast, and transcriptome analysis shows stronger effects on genome-wide expression in a double-tail subunit deletion mutant than in single-subunit deletion mutants. Unexpectedly, TATA-containing and SAGA-dependent genes were much more affected by impairment of tail module function than were TFIID-dependent genes. Consistent with this finding, Mediator and preinitiation complex association with SAGA-dependent promoters is substantially reduced in gal11/med15Δ med3Δ yeast, whereas association of TBP, Pol II, and other Mediator modules with TFIID-dependent genes is largely independent of the tail module. Thus, we have identified a connection between the Mediator tail module and the division of promoter dependence between TFIID and SAGA.
authors.affiliation: Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509, USA.
authors.forename: Suraiya A
authors.initials: SA
authors.lastname: Ansari
authors.forename: Mythily
authors.initials: M
authors.lastname: Ganapathi
authors.forename: Joris J
authors.initials: JJ
authors.lastname: Benschop
authors.forename: Frank C P
authors.initials: FC
authors.lastname: Holstege
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Wade
authors.forename: Randall H
authors.initials: RH
authors.lastname: Morse
mesh_terms: D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D016681:Genome, Fungal; D056892:Mediator Complex / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D035181:TATA-Box Binding Protein / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D035362:Transcription Factor TFIID / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: C058337:GAL11 protein, S cerevisiae; C470560:MED2 protein, S cerevisiae; D056892:Mediator Complex; C110281:PGD1 protein, S cerevisiae; C507785:SAGA complex, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035181:TATA-Box Binding Protein; D015534:Trans-Activators; D035362:Transcription Factor TFIID; D018844:Cyclin-Dependent Kinases