Nitrogen catabolite repression- (NCR-) sensitive genes, whose expression is highly repressed when provided with excess nitrogen and derepressed when nitrogen is limiting or cells are treated with rapamycin, are routinely used as reporters in mechanistic studies of the Tor signal transduction pathway in Saccharomyces cerevisiae. Two GATA factors, Gln3 and Gat1 are responsible for NCR-sensitive transcription, but recent evidence demonstrates that Tor pathway regulation of NCR-sensitive transcription bifurcates at the level of GATA factor localization. Gln3 requires Sit4 phosphatase for nuclear localization and NCR-sensitive transcription while Gat1 does not. In this paper we demonstrate that the extent to which Sit4 plays a role in NCR-sensitive transcription depends upon whether or not: (i) Gzf3, a GATA repressor homologous to Dal80, is active in the genetic background assayed, (ii) Gat1 is able to activate transcription of the assayed gene in the absence of Gln3 in that genetic background, and (iii) the gene chosen as a reporter is able to be transcribed by Gln3 or Gat1 in the absence of the other GATA factor. Together the data indicate that in the absence of these three pieces of information, overall NCR-sensitive gene transcription data are unreliable as Tor pathway readouts.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|