The eukaryotic two-component histidine kinase Sln1p regulates OCH1 via the transcription factor, Skn7p.
The yeast "two-component" osmotic stress phosphorelay consists of the histidine kinase, Sln1p, the phosphorelay intermediate, Ypd1p and two response regulators, Ssk1p and Skn7p, whose activities are regulated by phosphorylation of a conserved aspartyl residue in the receiver domain. Dephospho-Ssk1p leads to activation of the hyper-osmotic response (HOG) pathway, whereas phospho-Skn7p presumably leads to activation of hypo-osmotic response genes. The multifunctional Skn7 protein is important in oxidative as well as osmotic stress; however, the Skn7p receiver domain aspartate that is the phosphoacceptor in the SLN1 pathway is dispensable for oxidative stress. Like many well-characterized bacterial response regulators, Skn7p is a transcription factor. In this report we investigate the role of Skn7p in osmotic response gene activation. Our studies reveal that the Skn7p HSF-like DNA binding domain interacts with a cis-acting element identified upstream of OCH1 that is distinct from the previously defined HSE-like Skn7p binding site. Our data support a model in which Skn7p receiver domain phosphorylation affects transcriptional activation rather than DNA binding to this class of DNA binding site.
Li
Sheng
S
Department of Biological Sciences, University of Iowa, University of Iowa, Iowa City, Iowa 52242, USA.
Dean
Susan
S
Li
Zhijian
Z
Horecka
Joe
J
Deschenes
Robert J
RJ
Fassler
Jan S
JS
D001224:Aspartic Acid / Q000378:metabolism; D001665:Binding Sites; D002473:Cell Wall / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism* / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal; D047908:Intracellular Signaling Peptides and Proteins; D008364:Mannosyltransferases; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011494:Protein Kinases; D020218:Response Elements; D012441:Saccharomyces cerevisiae / Q000378:metabolism / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000502:physiology; D020079:Terminal Repeat Sequences; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; C075636:OCH1 protein, S cerevisiae; C083962:SKN7 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D001224:Aspartic Acid; D008364:Mannosyltransferases; D011494:Protein Kinases; C083749:SLN1 protein, S cerevisiae