title: Mediator protein mutations that selectively abolish activated transcription.
abstract: Deletion of any one of three subunits of the yeast Mediator of transcriptional regulation, Med2, Pgd1 (Hrs1), and Sin4, abolished activation by Gal4-VP16 in vitro. By contrast, other Mediator functions, stimulation of basal transcription and of TFIIH kinase activity, were unaffected. A different but overlapping Mediator subunit dependence was found for activation by Gcn4. The genetic requirements for activation in vivo were closely coincident with those in vitro. A whole genome expression profile of a Deltamed2 strain showed diminished transcription of a subset of inducible genes but only minor effects on "basal" transcription. These findings make an important connection between transcriptional activation in vitro and in vivo, and identify Mediator as a "global" transcriptional coactivator.
authors.affiliation: Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Myers
authors.forename: C M
authors.initials: CM
authors.lastname: Gustafsson
authors.forename: K C
authors.initials: KC
authors.lastname: Hayashibara
authors.forename: P O
authors.initials: PO
authors.lastname: Brown
authors.forename: R D
authors.initials: RD
authors.lastname: Kornberg
mesh_terms: D002474:Cell-Free System; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D008957:Models, Genetic; D009154:Mutation; D011494:Protein Kinases / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013329:Structure-Activity Relationship; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D015003:Yeasts / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C070633:Gal-VP16; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D011494:Protein Kinases; C060137:carboxy-terminal domain kinase