Differential regulation of transcription: repression by unactivated mitogen-activated protein kinase Kss1 requires the Dig1 and Dig2 proteins.
Kss1, a yeast mitogen-activated protein kinase (MAPK), in its unphosphorylated (unactivated) state binds directly to and represses Ste12, a transcription factor necessary for expression of genes whose promoters contain filamentous response elements (FREs) and genes whose promoters contain pheromone response elements (PREs). Herein we show that two nuclear proteins, Dig1 and Dig2, are required cofactors in Kss1-imposed repression. Dig1 and Dig2 cooperate with Kss1 to repress Ste12 action at FREs and regulate invasive growth in a naturally invasive strain. Kss1-imposed Dig-dependent repression of Ste12 also occurs at PREs. However, maintenance of repression at PREs is more dependent on Dig1 and/or Dig2 and less dependent on Kss1 than repression at FREs. In addition, derepression at PREs is more dependent on MAPK-mediated phosphorylation than is derepression at FREs. Differential utilization of two types of MAPK-mediated regulation (binding-imposed repression and phosphorylation-dependent activation), in combination with distinct Ste12-containing complexes, contributes to the mechanisms by which separate extracellular stimuli that use the same MAPK cascade can elicit two different transcriptional responses.
Bardwell
L
L
Department of Molecular and Cell Biology, Division of Biochemistry and Molecular Biology, University of California, Berkeley, CA 94720, USA.
Cook
J G
JG
Zhu-Shimoni
J X
JX
Voora
D
D
Thorner
J
J
D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D017930:Genes, Reporter; D005838:Genotype; D020928:Mitogen-Activated Protein Kinases; D008954:Models, Biological; D010675:Pheromones / Q000502:physiology; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
C102297:DIG1 protein, S cerevisiae; C102298:DIG2 protein, S cerevisiae; D005656:Fungal Proteins; D010675:Pheromones; D011994:Recombinant Proteins; C489241:STE12 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C075580:FUS3 protein, S cerevisiae; C541984:KSS1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases