Dataset Information

Integration of transcriptional and posttranslational regulation in a glucose signal transduction pathway in Saccharomyces cerevisiae.

ABSTRACT: Expression of the HXT genes encoding glucose transporters in the budding yeast Saccharomyces cerevisiae is regulated by two interconnected glucose-signaling pathways: the Snf3/Rgt2-Rgt1 glucose induction pathway and the Snf1-Mig1 glucose repression pathway. The Snf3 and Rgt2 glucose sensors in the membrane generate a signal in the presence of glucose that inhibits the functions of Std1 and Mth1, paralogous proteins that regulate the function of the Rgt1 transcription factor, which binds to the HXT promoters. It is well established that glucose induces degradation of Mth1, but the fate of its paralogue Std1 has been less clear. We present evidence that glucose-induced degradation of Std1 via the SCF(Grr1) ubiquitin-protein ligase and the 26S proteasome is obscured by feedback regulation of STD1 expression. Disappearance of Std1 in response to glucose is accelerated when glucose induction of STD1 expression due to feedback regulation by Rgt1 is prevented. The consequence of relieving feedback regulation of STD1 expression is that reestablishment of repression of HXT1 expression upon removal of glucose is delayed. In contrast, degradation of Mth1 is reinforced by glucose repression of MTH1 expression: disappearance of Mth1 is slowed when glucose repression of MTH1 expression is prevented, and this results in a delay in induction of HXT3 expression in response to glucose. Thus, the cellular levels of Std1 and Mth1, and, as a consequence, the kinetics of induction and repression of HXT gene expression, are closely regulated by interwoven transcriptional and posttranslational controls mediated by two different glucose-sensing pathways.

SUBMITTER: Kim JH

PROVIDER: S-EPMC1360249 | biostudies-literature | 2006 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Integration of transcriptional and posttranslational regulation in a glucose signal transduction pathway in Saccharomyces cerevisiae.

Kim Jeong-Ho JH Brachet Valérie V Moriya Hisao H Johnston Mark M

Eukaryotic cell 20060101 1

Expression of the HXT genes encoding glucose transporters in the budding yeast Saccharomyces cerevisiae is regulated by two interconnected glucose-signaling pathways: the Snf3/Rgt2-Rgt1 glucose induction pathway and the Snf1-Mig1 glucose repression pathway. The Snf3 and Rgt2 glucose sensors in the membrane generate a signal in the presence of glucose that inhibits the functions of Std1 and Mth1, paralogous proteins that regulate the function of the Rgt1 transcription factor, which binds to the H ...[more]

PMID: 16400179

Similar Datasets

Project description:Saccharomyces cerevisiae myosin type II-deficient (myo1?) strains remain viable and divide, despite the absence of a cytokinetic ring, by activation of the PKC1-dependent cell wall integrity pathway (CWIP). Since the myo1? transcriptional fingerprint is a subset of the CWIP fingerprint, the myo1? strain may provide a simplified paradigm for cell wall stress survival.To explore the post-transcriptional regulation of the myo1? stress response, 1,301 differentially regulated ribosome-bound mRNAs were identified by microarray analysis of which 204 were co-regulated by transcription and translation. Four categories of mRNA were significantly affected - protein biosynthesis, metabolism, carbohydrate metabolism, and unknown functions. Nine genes of the 20 CWIP fingerprint genes were post-transcriptionally regulated. Down and up regulation of selected ribosomal protein and cell wall biosynthesis mRNAs was validated by their distribution in polysomes from wild type and myo1? strains. Western blot analysis revealed accumulation of the phosphorylated form of eukaryotic translation initiation factor 2 (eIF2?-P) and a reduction in the steady state levels of the translation initiation factor eIF4Gp in myo1? strains. Deletion of GCN2 in myo1? abolished eIF2?p phosphorylation, and showed a severe growth defect. The presence of P-bodies in myo1? strains suggests that the process of mRNA sequestration is active, however, the three representative down regulated RP mRNAs, RPS8A, RPL3 and RPL7B were present at equivalent levels in Dcp2p-mCh-positive immunoprecipitated fractions from myo1? and wild type cells. These same RP mRNAs were also selectively co-precipitated with eIF2?-P in myo1? strains.Quantitative analysis of ribosome-associated mRNAs and their polyribosome distributions suggests selective regulation of mRNA translation efficiency in myo1? strains. Inhibition of translation initiation factor eIF2? (eIF2?-P) in these strains was by Gcn2p-dependent phosphorylation. The increase in the levels of eIF2?-P; the genetic interaction between GCN2 and MYO1; and the reduced levels of eIF4Gp suggest that other signaling pathways, in addition to the CWIP, may be important for myo1? strain survival. Selective co-immunoprecipitation of RP mRNAs with eIF2?-P in myo1? strains suggests a novel mode of translational regulation. These results indicate that post-transcriptional control is important in the myo1? stress response and possibly other stresses in yeast.

Dataset Information

Integration of transcriptional and posttranslational regulation in a glucose signal transduction pathway in Saccharomyces cerevisiae.

Publications

Integration of transcriptional and posttranslational regulation in a glucose signal transduction pathway in Saccharomyces cerevisiae.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets