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Regulation of mitochondrial metabolism under respiratory and fermentative conditions in yeast Michel Rigoulet
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I Crabtree Effect Repression of respiration by glucose Short term and long term events Crabtree positive and Crabtree negative strains
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Yeast growth on 0.6% glucose
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The main glucose-repression pathway
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Diauxic shift
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Diauxic shift: Induction of glyoxylate pathway dehydrogenases and Krebs cycle enzymes oxidative phosphorylation gluconeogenesis
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In Out I : Internal NADH dehydrogenase (Ndip) Ii : Succinate dehydrogenase III : External NADH dehydrogenase (Nde1p ; Nde2p) IV : Glycerol-3-P dehydrogenase (Gut2p) V : Lactate dehydrogenase VI : Glycerol-3-P dehydrogenase (Gpd1p ; Gpd2p) Dehydrogenases and respiratory chain in Saccharomyces cerevisiae
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Measurement of Respiratory Control
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Short term effect of glucose addition to respiring yeast: inhibition of respiration as a consequence of ?? Hypothesis 1) competition for free ADP and Pi 2) increase in phosphate potential (∆Gp) 3) activation of pyruvate decarboxylase 4) decrease in the outer membrane permeability for ADP (VDAC closed) new hypothesis: role of hexose-phosphate
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Glycolysis Lipid biogenesis mitochondria
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Non-phosphorylating conditionsPhosphorylating conditions G6P ; F6P ; F1,6bP Effect of glycolysis-derived hexoses-phosphate on the respiratory flux of isolated mitochondria in Crabtree-positive yeast
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Effect of F1,6bP on the G6P induced increase in the respiratory flux
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In Out I : Internal NADH dehydrogenase (Ndip) Ii : Succinate dehydrogenase III : External NADH dehydrogenase (Nde1p ; Nde2p) IV : Glycerol-3-P dehydrogenase (Gut2p) V : Lactate dehydrogenase VI : Glycerol-3-P dehydrogenase (Gpd1p ; Gpd2p) Dehydrogenases and respiratory chain in Saccharomyces cerevisiae
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Non-phosphorylating conditions ; Phosphorylating conditions Cytochrome oxydase activity in the presence of F1,6bP
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G6P ; F6P ; F1,6bP Effect of glycolysis-derived hexoses-phosphate on the mitochondrial complex III
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Effect of F1,6bP on the G6P induced stimulation of complex III activity
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Effect of glycolysis-derived hexoses-phosphate on the respiratory flux of isolated mitochondria in Crabtree-negative yeast
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Phosphorylating conditions Effect of F1,6bP on the respiratory flux in rat liver mitochondria
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