Open AccessSite-specific Srb10-dependent phosphorylation of the yeast Mediator subunit Med2 regulates gene expression from the 2-μm plasmid
Author(s) -
Magnus Hallberg,
Gennady V. Polozkov,
GuoZhen Hu,
Jenny Béve,
Claes M. Gustafsson,
Hans Ronne,
Stefan Björklund
Publication year - 2004
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0400221101
Subject(s) - mediator , biology , rna polymerase ii , protein subunit , phosphorylation , microbiology and biotechnology , gene , regulation of gene expression , transcriptional regulation , gene expression , genetics , promoter
The yeast Mediator complex is required for transcriptional regulation both in vivo and in vitro, and its function is conserved in all eukaryotes. Mediator interacts with both transcriptional activators and RNA polymerase II, but little is known about the mechanisms by which it operates at the molecular level. Here, we show that the cyclin-dependent kinase Srb10 interacts with, and phosphorylates, the Med2 subunit of Mediator both in vivo and in vitro. A point mutation of the single phosphorylation site in Med2 results in a strongly reduced expression of the REP1, REP2, FLP1, and RAF1 genes, which are all located on the endogenous 2-microm plasmid. Combined with previous studies on the effects of SRB10/SRB11 deletions, our data suggest that posttranslational modifications of Mediator subunits are important for regulation of gene expression.