Yeast Carbon Catabolite Repression
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TLDR
It is possible in certain cases to propose a partial model of the way in which the different elements involved in catabolite repression may be integrated, and preliminary evidence suggests that Snf1 is in a dephosphorylated state under these conditions.Abstract:
Glucose and related sugars repress the transcription of genes encoding enzymes required for the utilization of alternative carbon sources; some of these genes are also repressed by other sugars such as galactose, and the process is known as catabolite repression. The different sugars produce signals which modify the conformation of certain proteins that, in turn, directly or through a regulatory cascade affect the expression of the genes subject to catabolite repression. These genes are not all controlled by a single set of regulatory proteins, but there are different circuits of repression for different groups of genes. However, the protein kinase Snf1/Cat1 is shared by the various circuits and is therefore a central element in the regulatory process. Snf1 is not operative in the presence of glucose, and preliminary evidence suggests that Snf1 is in a dephosphorylated state under these conditions. However, the enzymes that phosphorylate and dephosphorylate Snf1 have not been identified, and it is not known how the presence of glucose may affect their activity. What has been established is that Snf1 remains active in mutants lacking either the proteins Grr1/Cat80 or Hxk2 or the Glc7 complex, which functions as a protein phosphatase. One of the main roles of Snf1 is to relieve repression by the Mig1 complex, but it is also required for the operation of transcription factors such as Adr1 and possibly other factors that are still unidentified. Although our knowledge of catabolite repression is still very incomplete, it is possible in certain cases to propose a partial model of the way in which the different elements involved in catabolite repression may be integrated.read more
Citations
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Journal ArticleDOI
Glucose sensing through the Hxk2-dependent signalling pathway
TL;DR: The findings show that the main role of Hxk2 in the glucose signalling pathway is the interaction with Mig1 to generate a repressor complex located in the nucleus of S. cerevisiae.
Journal ArticleDOI
Comparative Proteome Analysis of Saccharomyces cerevisiae Grown in Chemostat Cultures Limited for Glucose or Ethanol
Annemieke Kolkman,Maurien M.A. Olsthoorn,Carola E.M. Heeremans,Albert J. R. Heck,Monique Slijper +4 more
TL;DR: It is shown here that the combined approach of chemostat cultivation and comprehensive proteome analysis allowed us to study the primary effect of single limiting conditions on the yeast proteome and unravel which processes in the central carbon metabolism were regulated at the level of the proteome, and which processes at thelevel of transcriptome.
Journal ArticleDOI
Regulation of glucose utilization in yeast
TL;DR: In this article, two transporter-like proteins have been shown to function as glucose sensors in a pathway for glucose induction of transporter genes, and the role of Snf1 in inhibiting Mig1 and regulating activators.
Journal ArticleDOI
Regulations of sugar transporters: insights from yeast
TL;DR: Current understanding of multiple interconnected glucose-sensing systems and signal-transduction pathways that ensure fast and optimum expression of genes encoding hexose transporters in three yeast species, Saccharomyces cerevisiae, Kluyveromyces lactis and Candida albicans are described.
Journal ArticleDOI
Convergence of the Target of Rapamycin and the Snf1 Protein Kinase Pathways in the Regulation of the Subcellular Localization of Msn2, a Transcriptional Activator of STRE (Stress Response Element)-regulated Genes
TL;DR: Active Snf1 and the TOR kinase pathway may affect similar cytosolic steps in the regulation of the subcellular localization of Msn2, a transcriptional activator of STRE (stressresponse element)-regulated genes, which is modulated by carbon source availability.
References
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TL;DR: The central hypothesis is that the AMP-activated protein kinase cascade appears to be an ancient system which evolved to protect cells against the effects of nutritional or environmental stress, and protects the cell by switching off ATP-consuming pathways and switching on alternative pathways for ATP generation.
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Two differentially regulated mRNAs with different 5′ ends encode secreted and intracellular forms of yeast invertase
Marian Carlson,David Botstein +1 more
TL;DR: A model is proposed to account for the synthesis and regulation of the two forms of inverts: the larger, regulated mRNA contains the initiation codon for the signal sequence required for synthesis of the secreted, glycosylated form of invertase; the smaller, constitutively transcribed mRNA begins within the coding region of the signal sequences, resulting in synthesis ofThe intracellular enzyme.
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Characterization of the AMP-activated Protein Kinase Kinase from Rat Liver and Identification of Threonine 172 as the Major Site at Which It Phosphorylates AMP-activated Protein Kinase
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