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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Expression and compartmentation of the glucose repressor CRE1 from the phytopathogenic fungus Sclerotinia sclerotiorum.
TL;DR: It is proposed that filamentous fungi regulate the activity of the glucose repressor by controlling its nuclear translocation, suggesting homologous post-translational regulations of glucose repressors in fungi.
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Antioxidant activity of L-ascorbic acid in wild-type and superoxide dismutase deficient strains of Saccharomyces cerevisiae
TL;DR: The results demonstrate that due to the damage caused by paraquat, the antioxidant protection of L-ascorbic acid seems to be mediated by catalase levels in yeast cells.
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Awakening the endogenous Leloir pathway for efficient galactose utilization by Yarrowia lipolytica
Zbigniew Lazar,Zbigniew Lazar,Zbigniew Lazar,Heber Gamboa-Meléndez,Heber Gamboa-Meléndez,Anne-Marie Crutz-Le Coq,Anne-Marie Crutz-Le Coq,Cécile Neuvéglise,Cécile Neuvéglise,Jean-Marc Nicaud,Jean-Marc Nicaud +10 more
TL;DR: The construction of a Y. lipolytica strain able to produce citric acid and lipids from galactose is a very important step in bypassing issues related to the use of food-based substrates in industrial applications.
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Increased heme synthesis in yeast induces a metabolic switch from fermentation to respiration even under conditions of glucose repression.
TL;DR: It is found that heme induces transcription of HAP4, the transcriptional activation subunit of the Hap2/3/4/5p complex, required for growth on nonfermentable carbon sources, in a Hap1p- and Hap4-dependent manner, leading to a switch from fermentation to respiration.
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Yeast as a model to study mitochondrial mechanisms in ageing.
Mario H. Barros,Fernanda Marques da Cunha,Graciele Almeida de Oliveira,Erich B. Tahara,Alicia J. Kowaltowski +4 more
TL;DR: In this article, the authors review mitochondrial characteristics involved in yeast longevity, including biogenesis, autophagy, respiration and oxidative phosphorylation, nutrient sensing, mitochondria-nuclear signaling, redox state and mitochondrial DNA integrity.
References
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