Mediator protein mutations that selectively abolish activated transcription.
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.
Myers
L C
LC
Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Gustafsson
C M
CM
Hayashibara
K C
KC
Brown
P O
PO
Kornberg
R D
RD
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
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