Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.2.1.13 (glyceraldehyde-3-phosphate dehydrogenase)
6,511 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The steady-state levels of messenger RNA (mRNA) of the glucose transporters 1 and 3 and the glycolytic enzymes hexokinase, phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase and pyruvate dehydrogenase were measured in up to seven brain regions of the rat in a recently developed animal model of 'behavioral dependence' on ethanol. Irreversible behavioral dependence, including loss of control, was induced by offering the rats the choice between ethanol and water over a 9-month period (Group A). This group was compared with a group given the choice between ethanol and water for only 2 months (not yet behaviorally dependent, Group B), a group forced to consume ethanol as sole fluid over a 9-month period (not behaviorally dependent, Group C) and ethanol-naive control rats. All groups were sacrificed 1 month after ethanol withdrawal. The mRNA concentrations of both neuronal glucose transporter 3 and the key glycolytic enzymes phosphofructokinase and pyruvate dehydrogenase were significantly reduced in the hippocampi of the rats behaviorally dependent on ethanol (Group A). No significant changes were seen in any of the remaining brain regions (e.g., cortical areas, limbic forebrain, amygdala, midbrain) in Group A, or in any brain area at all in Groups B and C. The results show that chronic consumption of ethanol in a free-choice situation may impair neuronal glucose uptake and glycolytic flux. This effect is manifested exclusively in the hippocampus and is specifically related to the development of behavioral dependence, since it was not found after forced administration of large amounts of ethanol (Group C).
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PMID:Gene expression of glucose transporters and glycolytic enzymes in the CNS of rats behaviorally dependent on ethanol. 1003 12

The purpose of this report was to describe mRNA abundance for the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate kinase, and pyruvate dehydrogenase in ischemic and adjacent aerobic myocardium. Mechanical, metabolic, and mRNA data were acquired in a pig model of regulated coronary flow using extracorporeal perfusion. Trials of coronary hypoperfusion included sustained and intermittent exposures of acute ischemia with or without reperfusion. These were compared with a chronic 4-day model of partial coronary stenosis. In ischemic tissues, levels of mRNA, normalized by mRNA for beta-actin, were increased over control values for GAPDH (range 2.7- to 4.6-fold), pyruvate kinase (2.9-fold), and pyruvate dehydrogenase (2.1-fold). It is of interest that increases in mRNA levels over control values were also observed in adjacent aerobic heart muscle from intervention hearts, including 3.6- to 4.5-fold elevations in message for GAPDH and a 2.1-fold increase in signal for pyruvate dehydrogenase. Augmentation in mRNA abundance occurred in as short a time as 40 min of ischemia and was maintained for as long as 4 days in partial coronary stenosis. Whether the former time was of an interval sufficient to affect protein production is problematic, but the latter time was ample to influence enzyme concentration, which may in turn have regulated glycolysis in this condition.
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PMID:Alteration of gene expression for glycolytic enzymes in aerobic and ischemic myocardium. 1051 79

Artificial rearing of 4-day-old rat pups on a high-carbohydrate (HC) milk formula results in the immediate onset of hyperinsulinemia. To evaluate these early changes, studies on pancreatic function were carried out on 12-day-old HC rats and compared with age-matched mother-fed (MF) pups. The plasma insulin and glucagon contents were increased sixfold and twofold, respectively, in HC rats compared with MF rats. There was a distinct leftward shift in the glucose-stimulated insulin secretory pattern for HC islets. HC islets secreted insulin in the absence of any added glucose and in the presence of Ca(2+) channel inhibitors. The activities of glucokinase, hexokinase, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate dehydrogenase complex were significantly increased in HC islets compared with MF islets. The protein contents of GLUT-2 and hexokinase were significantly increased in HC islets. These findings indicate that a nutritional intervention in the form of a HC formula only during the suckling period has a profound influence on pancreatic function, causing the onset of hyperinsulinemia.
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PMID:A dietary intervention (high carbohydrate) during the neonatal period causes islet dysfunction in rats. 1060 Jul 96

Excessive zinc influx may contribute to neuronal death after certain insults, including transient global ischemia. In light of evidence that levels of intracellular free Zn(2+) associated with neurotoxicity may be sufficient to inhibit glyceraldehyde-3-phosphate dehydrogenase (GAPDH), experiments were performed looking for reduced glycolysis and energy failure in cultured mouse cortical neurons subjected to lethal Zn(2+) exposure. As predicted, cultures exposed for 3-22 hr to 40 mixroM Zn(2+) developed an early increase in levels of dihydroxy-acetone phosphate (DHAP) and fructose 1,6-bisphosphate (FBP) and a progressive loss of ATP levels, followed by neuronal cell death; furthermore, addition of the downstream glycolytic substrate pyruvate to the bathing medium attenuated the fall in ATP and neuronal death. However, an alternative to direct Zn(2+) inhibition of GAPDH was raised by the observation that Zn(2+) exposure also induced an early decrease in nicotinamide-adenine dinucleotide (NAD(+)) levels, an event itself capable of inhibiting GAPDH. Favoring this indirect mechanism of GAPDH inhibition, the neuroprotective effects of pyruvate addition were associated with normalization of cellular levels of NAD(+), DHAP, and FBP. Zn(2+)-induced neuronal death was also attenuated by addition of the energy substrate oxaloacetate, the activator of pyruvate dehydrogenase, dichloroacetate, or the inhibitors of NAD(+) catabolism, niacinamide or benzamide. Acetyl carnitine, alpha-keto butyrate, lactate, and beta-hydroxy-butyrate did not attenuate Zn(2+)-induced neurotoxicity, perhaps because they could not regenerate NAD(+) or be used for energy production in the presence of glucose.
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PMID:Zinc-induced cortical neuronal death: contribution of energy failure attributable to loss of NAD(+) and inhibition of glycolysis. 1077 77

Lead is known to be a potent inhibitor of many enzymes working in the brain, thus possibly inducing functional problems in the brain under pathophysiological conditions. Among such enzymes are those involved in glucose metabolism and energy production. We investigated the inhibitory effects of low-level lead on brain hexokinase (HK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate kinase (PK) and pyruvate dehydrogenase complex (PDHc) with rat brain homogenate. PDHc was distinctively inhibited when low-dose lead acetate was added last of all (IC50 = 5 microM) to the reaction mixture. The other enzymes were completely resistant to 5 microM of lead acetate. When the homogenate was preincubated with lead acetate HK was dramatically inhibited by low-level lead acetate (1-5 microM), in a manner dependent on both preincubation time and lead concentration. However, the inhibitory effect was abolished by coincubation with its substrates, glucose or ATP. The results suggest that exposure to low levels of lead may increase the risk of cerebral hypometabolism caused by direct inhibition of specific glucose-utilizing enzymes. In this context, lead might be regarded as a risk factor in the abnormal glucose metabolism seen in some kinds of neurodegenerative disorders such as sporadic Alzheimer's disease.
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PMID:Effects of low-level lead on glycolytic enzymes and pyruvate dehydrogenase of rat brain in vitro: relevance to sporadic Alzheimer's disease? 1082 44

We have analyzed the proteins that are oxidatively damaged when Saccharomyces cerevisiae cells are exposed to stressing conditions. Carbonyl groups generated by hydrogen peroxide or menadione on proteins of aerobically respiring cells were detected by Western blotting, purified, and identified. Mitochondrial proteins such as E2 subunits of both pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase, aconitase, heat-shock protein 60, and the cytosolic fatty acid synthase (alpha subunit) and glyceraldehyde-3-phosphate dehydrogenase were the major targets. In addition we also report the in vivo modification of lipoamide present in the above-mentioned E2 subunits under the stressing conditions tested and that this also occurs with the homologous enzymes present in Escherichia coli cells that were used for comparative analysis. Under fermentative conditions, the main protein targets in S. cerevisiae cells treated with hydrogen peroxide or menadione were pyruvate decarboxylase, enolase, fatty acid synthase, and glyceraldehyde-3-phosphate dehydrogenase. Under the stress conditions tested, fermenting cells exhibit a lower viability than aerobically respiring cells and, consistently, increased peroxide generation as well as higher content of protein carbonyls and lipid peroxides. Our results strongly suggest that the oxidative stress in prokaryotic and eukaryotic cells shares common features.
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PMID:Oxidative stress promotes specific protein damage in Saccharomyces cerevisiae. 1085 12

Recombinant S. cerevisiae strains, with elevated levels of the enzymes of lower glycolysis (glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate mutase, phosphoglycerate kinase, enolase, pyruvate kinase, pyruvate decarboxylase and alcohol dehydrogenase) were physiologically characterized. During growth on glucose the enzyme levels in the recombinant strains (YHM4 and YHM7) were 1.1-3.4-fold higher than in the host strain (CEN.PK.K45). The recombinant strains were grown in aerobic or anaerobic batch cultures on glucose or a mixture of glucose and galactose. The specific ethanol production rates in the recombinant strains were the same as for the host strain and the physiological behaviour of the recombinant strains and the host strain was similar. When the cellular demand for ATP was increased by means of glucose pulses (final concentrations of 3.9 g/l or 2.0 g/l, respectively) to aerobic chemostat cultures maintained at a dilution rate of 0.08/h, the specific carbon dioxide production rate (qCO(2)) of CEN.PK.K45 accelerated at 6x10(-3) mmol/g/min(2) during the first 15 min, whereas during the same time period the qCO(2) of YHM7 accelerated twice as fast at 12x10(-3) mmol/g/min(2), indicating a higher fermentative capacity in the recombinant strain.
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PMID:Simultaneous overexpression of enzymes of the lower part of glycolysis can enhance the fermentative capacity of Saccharomyces cerevisiae. 1101 29

Growth and starvation of baker's yeast was monitored by on-line microcalorimetry and cells originating from four different physiological states were stored at low temperature (4 degrees C) for up to 26 days. The different physiological states were designated F (respiro-Fermentative phase of growth), R (initial Respiratory phase of growth), -N (non-growing state because of Nitrogen depletion), and -NC (non-growing state because of both Nitrogen and Carbon depletion). The cells were tested before and after cold storage for their fermentative capacity, and characterised by 2D gel analysis (and subsequent quantitative silver staining and image analysis with software PDQUEST) for their levels of six enzymes of the glycolytic pathway (hexokinase 2 (Hxk2p), fructose bisphosphate aldolase (Fba1p), glyceraldehyde-3-phosphate dehydrogenase (Tdh3p), enolase A (Enolp), enolase B (Eno2p), and triose phosphate isomerase (Tpi1p)) and two enzymes of the fermentative branch (pyruvate decarboxylase (Pdc1p) and alcohol dehydrogenase (Adh1p)). The enzymes Hxk2p, Tdh3p, Eno2p, Pdc1p and Adh1p were down-regulated by 25-80% during the transition between the F and R states. During the transition to non-growing states (-N and -NC states), the levels of Hxk2p, Tdh3p and Eno2p were further reduced. However, after cold storage, the glycolytic and fermentative enzymes of the different physiological states were expressed to the same extent. In contrast, the fermentative capacity differed between the states; the R-state cells were superior compared to cells from the other states tested and preserved more than 50% of their initial fermentative capacity (6 mmol ethanol per gram dry weight and hour). Our data therefore clearly demonstrate that persistence of fermentative capacity during total starvation at low temperature after as long as 1 month is strongly dependent on the physiological state from which the cells originate. However, the level of expression of the glycolytic enzymes could not explain the difference in fermentative capacity of the different physiological states after cold storage.
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PMID:Fermentative capacity after cold storage of baker's yeast is dependent on the initial physiological state but not correlated to the levels of glycolytic enzymes. 1178 28

3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction is widely used to evaluate cell proliferation and viability. MTT reduction is interpreted to be indicative of cellular metabolic activity, and the site of reduction includes both mitochondrial and cytosolic redox reactions. Astrocytes are believed to rely mainly on glycolysis for ATP generation, whereas neurons are considered to depend more on oxidative metabolism. The present study, therefore, tested the substrate-preference of glucose and its metabolites for MTT reduction in cultures of rat type 1 astroglia and neurons.MTT specific activity of astroglia was much higher than that of neurons. Astroglial MTT reducing activity in glucose-free medium or 2mM glucose with iodoacetate (5mM) was completely blocked. In glucose-depleted medium, 2mM lactate, pyruvate, malate, or acetate elicited minimal increases in MTT reduction by astroglia. In contrast, MTT reducing activity in neurons was enhanced two-fold by pyruvate and the reducing activity of lactate was equivalent to that of glucose, while malate had a small and acetate had no effect on MTT reduction. These results indicate that these two cell types differ markedly in their substrate-preferences for MTT reduction. In astroglia, MTT reduction reflects mainly cytosolic redox activity and is dependent on glyceraldehyde-3-phosphate dehydrogenase. In neurons, pyruvate dehydrogenase supports MTT reduction more effectively than glucose or lactate, even though both of these substrates can produce NADH and pyruvate.
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PMID:Substrate-dependence of reduction of MTT: a tetrazolium dye differs in cultured astroglia and neurons. 1182 Nov 52

Among nutrients, the role of water-soluble vitamins as genetic expression modulators has not been exhaustively stu-died. Relevant information is shown herein on the present state of the art in this field. For example, vitamin C deficiency leads to a decrease in mRNA levels of apolipoprotein A1 (Apo A1) in liver. Biotin participates in the regulation, both at mRNA and protein level, of the enzymes that participate in its own metabolic cycle and of enzymes that contribute to glucose metabolism. Thiamine regulates the expression of some genes that code for enzymes using thiamine diphosphate as cofactor. Thiamine deficiency diminishes the mRNA levels of transketolase and pyruvate dehydrogenase. It has been shown in riboflavin-deficient rats that FAD regulates some acetyl CoA dehydrogenases, producing a marked increase in mRNA levels. Nicotinamide positively regulates glyceraldehyde-3-phosphate dehydrogenase when NADH is added. Vitamin B6 modulates the expression of a variety of genes that respond to hormones. Vitamin B12 increases concentrations of the enzymatic protein methionine synthetase and doe not affect mRNA levels, which implies that this protein is regulated by its cofactor post-transcriptionally. Most mechanisms involved in these regulation examples are not known, which opens new research areas for the future.
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PMID:[Importance of water-soluble vitamins as regulatory factors of genetic expression]. 1199 11


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