Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A recessive mutant cat1-1, wild type CAT1, was isolated in Saccharomyces cerevisiae. It did not grow on glycerol nor ferment maltose even with fully constitutive, glucose resistant maltase synthesis. It prevented derepression of isocitrate lyase, fructose-1,6-diphosphatase and maltase in a constitutive but glucose sensitive maltase mutant. Derepression of malate dehydrogenase was retarded and slowed down. Sucrose fermentation and invertase synthesis was not affected. Respiration was normal. From this mutant, two reverse mutants were isolated. One was recessive, acted as a suppressor of cat1-1 and was called cat2-1, wild type CAT2; the other was dominant and allelic to CAT1 and designated CAT1-2d and cat2-1 caused an earlier derepression of enzymes studied but did not affect the repressed nor the fully derepressed enzyme levels. CAT1-2d and cat2-1 did not show any additive effects. It is proposed that carbon catabolite repression acts in two ways. The direct way represses synthesis of sensitive enzymes, during growth on repressing carbon sources whereas the other way regulates the derepression process. After alleviation of carbon catabolite repression, gene CAT1 becomes active and prevents the activity of CAT2 which functions as a repressor of sensitive enzyme synthesis. The CAT2 gene product has to be eliminated before derepression can actually occur. The time required for this causes a delay in derepression after the depletion of a repressible carbon source. cat1-1 cannot block CAT2 activity and therefore, derepression is blocked. cat2-1 is inactive and derepression can start after carbon catabolite repression has ceased. CAT1-2d permanently active as a repressor of CAT2 and eliminates the delay in derepression.
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PMID:Genetics of carbon catabolite repression in Saccharomycess cerevisiae: genes involved in the derepression process. 19 40

Yeast mutants with glucose-insensitive formation of mitochondrial enzymes were isolated starting with a strain completely lacking alcohol dehydrogenase activity. The mutations could uniquely be attributed to a single nuclear gene, designated CCR80. They were largely dominant. Glucose-resistant enzyme formation was most prominent with regard to mitochondrial enzymes succinate dehydrogenase and NADH: cytochrome c oxidoreductase. The effect of CCR80r mutations was rather small but significant on the gluconeogenetic enzymes isocitrate lyase, malate synthase and fructose-1,6-bisphosphatase and on invertase synthesis. The repressive effect of maltose in CCR80r mutants was also reduced showing that glucose-resistance is not caused by a mere hexose uptake defect. This regulatory disorders were not accompanied by reduced levels of glycolytic enzymes or drastically altered levels of glycolytic intermediates. Aerobic fermentation of glucose was almost completely inhibited in the mutants; anaerobic glucose degradation was reduced but not completely abolished. Therefore, the mutants appear to be altered in the regulation of glycolysis. A largely glucose-resistant synthesis of respiratory enzymes is obviously a corollary of this alteration.
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PMID:A yeast mutant with glucose-resistant formation of mitochondrial enzymes. 20 62

Using a new selection protocol we have identified and preliminarily characterized three new loci (ADR7, ADR8 and ADR9) which affect ADH2 (alcohol dehydrogenase isozyme II) expression. Mutants were selected which activate ADH2 expression in the presence of an over-expressed, normally inactive ADR1 allele. The mutants had very similar phenotypes with the exception that one was temperature sensitive for growth. In the absence of any ADR1 allele, the mutants allowed ADH2 to partially escape glucose repression. However, unlike wildtype strains deleted for ADR1, the mutants were able to efficiently derepress ADH2. The mutations allowed a small escape from glucose repression for secreted invertase, but had no effect on the glucose repression of isocitrate lyase or malate dehydrogenase. The mutations were shown to be nonallelic to a wide variety of previously characterized mutations, including mutations that affect other glucose-repressed enzymes.
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PMID:Identification and characterization of three genes that affect expression of ADH2 in Saccharomyces cerevisiae. 142 33

Seven dominant mutations showing greatly enhanced resistance to the glucose repression of galactokinase synthesis have been isolated from GAL81 mutants, which have the constitutive phenotype but are still strongly repressible by glucose for the synthesis of the Leloir enzymes. These glucose-resistant mutants were due to semidominant mutations at either of two loci, GAL82 and GAL83. Both loci are unlinked to the GAL81- gal4, gal80, or gal7 X gal10 X gal1 locus or to each other. The GAL83 locus was mapped on chromosome V at a site between arg9 and cho1. The GAL82 and GAL83 mutations produced partial resistance of galactokinase to glucose repression only when one or both of these mutations were combined with a GAL81 or a gal80 mutation. The GAL82 and GAL83 mutations are probably specific for expression of the Leloir pathway and related enzymes, because they do not affect the synthesis of alpha-D-glucosidase, invertase, or isocitrate lyase.
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PMID:Isolation and characterization of dominant mutations resistant to carbon catabolite repression of galactokinase synthesis in Saccharomyces cerevisiae. 676 98

Isocitrate lyase is a key catalyst of the glyoxylate cycle. A feature of the enzyme from higher plants is the high instability, that causes innumerable problems in working for characterization of the enzyme. The present communication demonstrates that the optimal conditions for the storage of isocitrate lyase from Pinus pinea are: the use of a low temperature (possibly below -20 degrees C), the realization of a high endogenous protein concentration of the enzyme preparations, or, above all when long storage conservation is necessary, the preservation of the enzyme in dried form (acetone precipitation), under vacuum at 4 degrees C. The data reported in this paper seem to exclude, in the above studied conditions, a role for serine proteases in the destabilization of the enzyme. The thiol compounds are not determinant and no effect is obtained by adding exogenous proteins (serum albumin, beta-fructosidase).
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PMID:On the stability of isocitrate lyase from Pinus pinea. 712 56

The compartmentation of key processes in sugar, organic acid and amino acid metabolism was studied during the development of the flesh and seeds of grape (Vitis vinifera L.) berries. Antibodies specific for enzymes involved in sugar (cell wall and vacuolar invertases, pyrophosphate: fructose 6-phosphate phosphotransferase, aldolase, NADP-glyceraldehyde-P dehydrogenase, cytosolic fructose 1,6-bisphosphatase), photosynthesis (Rubisco, fructose 1,6-bisphosphatase, sedoheptulose 1,7-bisphosphatase), amino acid metabolism (cytosolic and mitochondrial aspartate aminotransferases, alanine aminotransferase, glutamate dehydrogenase, glutamine synthetase), organic acid metabolism (phosphoenolpyruvate carboxylase, NAD- and NADP-dependent malic enzyme, ascorbate peroxidase), and lipid metabolism (acetyl CoA carboxylase, isocitrate lyase) were used to determine how their abundance changed during development. There were marked changes in the abundance of many of these enzymes in both the flesh and seeds. The intercellular location of some enzymes was investigated using immunohistochemistry. Several enzymes (e.g. phosphoenolpyruvate carboxylase and those involved in amino acid metabolism) were associated with tissues likely to function in the transport of imported assimilates, such as the vasculature. Although other enzymes (e.g. NADP-malic enzyme and soluble acid invertase, involved in the metabolism of sugars and organic acids) were largely present in the parenchyma cells of the flesh, their distribution was extremely heterogeneous. This study shows that when considering the metabolism of complex structures such as fruit, it is essential to consider how metabolism is compartmentalized between and within different tissues, even when they are apparently structurally homogeneous.
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PMID:An immunohistochemical study of the compartmentation of metabolism during the development of grape (Vitis vinifera L.) berries. 1093 59

Cytokinin treatment is known to promote expansion of light-grown excised radish (Raphanus sativus L. cv Crimson Giant) cotyledons. This expansion, at least in part, seems to be related to an increased accumulation of osmotically active reducing sugars. Kinetin treatment did not cause increased levels of isocitrate lyase activity over the controls, but stimulated increased levels of two invertase forms, designated types I and II. Type I was soluble and type II was insoluble after homogenization in 10 millimolar tris(hydroxymethyl)aminomethane-HCl (pH 7.0). Both types were soluble after homogenization in 300 millimolar NaCl. At low salt concentration, type II was retained on a diethylamioethyl-cellulose column and type I was not. Type II was then eluted from the column at high salt concentration. Types I and II exhibited pH optima of 5.3 and 4.3, Michaelis constants of 4.96 and 1.23 millimolar sucrose, and molecular weights of 65,000 and 57,000 daltons, respectively. The kinetin promotion of reducing sugar accumulation may be related to increased levels of the two invertase forms, but is probably not a result of direct cytokinin-stimulated glyoxysomal activity.
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PMID:Invertase activity and the kinetin-stimulated enlargement of detached radish cotyledons. 1666 12

The yeast Yarrowia lipolytica is able to secrete high amounts of several organic acids under conditions of growth limitation and carbon source excess. Here we report the production of citric acid (CA) in a fed-batch cultivation process on sucrose using the recombinant Y. lipolytica strain H222-S4(p67ICL1) T5, harbouring the invertase encoding ScSUC2 gene of Saccharomyces cerevisiae under the inducible XPR2 promoter control and multiple ICL1 copies (10-15). The pH-dependent expression of invertase was low at pH 5.0 and was identified as limiting factor of the CA-production bioprocess. The invertase expression was sufficiently enhanced at pH 6.0-6.8 and resulted in production of 127-140 g l(-1) CA with a yield Y (CA) of 0.75-0.82 g g(-1), whereas at pH 5.0, 87 g l (-1) with a yield Y (CA) of 0.51 g g(-1) were produced. The CA-productivity Q (CA) increased from 0.40 g l (-1) h(-1) at pH 5.0 up to 0.73 g l (-1) h(-1) at pH 6.8. Accumulation of glucose and fructose at high invertase expression level at pH 6.8 indicated a limitation of CA production by sugar uptake. The strain H222-S4(p67ICL1) T5 also exhibited a gene-dose-dependent high isocitrate lyase expression resulting in strong reduction (<5%) of isocitric acid, a by-product during CA production.
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PMID:Citric acid production from sucrose using a recombinant strain of the yeast Yarrowia lipolytica. 1744 58

It is uncertain whether the enzymes pyruvate orthophosphate dikinase (PPDK) or isocitrate lyase (ICL) are present in the pericarp of grape, in which they could function in gluconeogenesis. The occurrence of these and other enzymes was investigated in the pericarp of three cultivars of grape (Vitis vinifera L.). In particular, the abundance of the enzymes aldolase, glutamine synthase (GS), acid invertase, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPC), PPDK and ICL were determined during the development of the pericarp of the cultivars Cabernet Sauvignon, Chardonnay and Zibibbo. PPDK and ICL were not detected at any stage of development. Each of the other enzymes showed different changes in abundance during development. However, for a given enzyme its changes in abundance were similar in each cultivar. In the ripe pericarp of Cabernet Sauvignon, PEPC, cytosolic GS and aldolase were equally distributed between the vasculature and parenchyma cells of the flesh and skin. The absence or very low abundance of PPDK provides strong evidence that any gluconeogenesis from malate utilises phosphoenolpyruvate carboxykinase (PEPCK). The absence or very low abundance of ICL in the pericarp precludes any gluconeogenesis from ethanol.
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PMID:Occurrence of a number of enzymes involved in either gluconeogenesis or other processes in the pericarp of three cultivars of grape (Vitis vinifera L.) during development. 2530 29