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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The creA204, creB15 and creC27 mutations have been shown to cause carbon catabolite derepression of acetly CoA synthase and isocitrate lyase in Aspergillus nidulans. A recessive mutation, cre-34, which is linked to the creC gene, results in these enzymes being more sensitive than cre or wildtype strains to catabolite repression. The acetamidase levels of strains containing cre mutations have been investigated and provide support for the hypothesis that an acetate metabolite, rather than acetamide, induces this enzyme.
Mol Gen Genet 1977 Nov 04
PMID:Increased and decreased sensitivity to carbon catabolite repression of enzymes of acetate metabolism in mutants of Aspergillus nidulans. 2 91

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.
Mol Gen Genet 1977 Feb 28
PMID:Genetics of carbon catabolite repression in Saccharomycess cerevisiae: genes involved in the derepression process. 19 40

Yeast mutants deficient in the constitutive ADHI (adc 1) were used for the isolation of mutants with deficiencies of the intermediary carbon metabolism, and of mutants defective in carbon catabolite derepression. Mutants were recognized by their inability to grow on YEP-glycerol and/or on ethanol synthetic complete medium. They were either defective in isocitrate lyase (ic11), succinate dehydrogenase (sdh1), or malate dehydrogenase (mdh1, mdh2), mdh-mutants could not uniformely be appointed to one of the known MDH isozymes. Homozygous mdh and sdh1 diploids are unable to sporulate. Three gene loci could be identified by mutants pleiotropically defective in many or all of the enzymes tested In ccr 1 mutants, derepression of isocitrate lyase, fructose-1,6-diphosphatase, ADHII and possibly of the cytoplasmic MDH is prevented, whereas the mitochondrial TCA-cycle enzymes, succinate dehydrogenase and malate dehydrogenase, are not significantly affected. CCR2 and CCR3 have quite similar action spectra. Both genes are obviously necessary for derepression of all enzymes tested. It could be shown that ccr1, ccr2 and ccr3 mutants are not respiratory deficient.
Mol Gen Genet 1977 Jul 20
PMID:Isolation and characterization of yeast mutants defective in intermediary carbon metabolism and in carbon catabolite derepression. 19 91

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.
Mol Gen Genet 1978 Feb 27
PMID:A yeast mutant with glucose-resistant formation of mitochondrial enzymes. 20 62

Thirteen chromosomal loci have been identified which affect acetate metabolism in Coprinus. Mutants at only two loci, acu-l and acu-7, are deficient in isocitrate lyase (ICL) (EC 4.1.3.1) activity. acu-1 mutants are unable to induce ICL because they lack acetyl-CoA synthetase which is required to convert acetate to the metabolic inducer of ICL. acu-7 is the structural gene for ICL. This was shown by selecting temperature sensitive acu+ revertants resulting from a second mutation within the acu-7 gene. One such revertant was shown to produce an ICL protein which was more thermolabile than the wild type enzyme. Other workers have postulated that ICL activity is important during asexual morphogenesis in fungi. No evidence was found for this in Coprinus. The morphological mutant oidial, which produces abundant asexual spores even in submerged culture, had the same low uninduced level of ICL activity as the wild type. Moreover, an acu-7 mutation had no effect on the expression of the oidial phenotype.
Mol Gen Genet 1977 Dec 09
PMID:Genetics and function of isocitrate lyase in Coprinus. 60 Feb 68

Recently it has been demonstrated that hydroxylamine is an activator of triglyceride catabolism. We have studied the effect of hydroxylamine on isocitrate lyase activity and lipid catabolism and have noted a stimulation of isocitrate lyase biosynthesis by 5 mM hydroxylamine. The specificity of this effect was tested with a number of representative enzymes of other metabolic pathways. In an attempt to study the possible mechanism of action of hydroxylamine we have also tested the effects of two substances that are structural or functional analogues of hydroxylamine, namely, ethanolamine and hydrazine, both on the enzyme level in plant cultures and on the activity of enzyme preparations. From our data we may conclude that "de nove" biosynthesis of isocitrate lyase depends on the reaction of hydroxylamine or hydrazine with glyoxylate to give the corresponding oxime and hydrazone. The removal of glyoxylate from the biological equilibrium in this way could cause extra formation of isocitrate lyase.
Mol Cell Biochem 1977 Apr 12
PMID:Stimulation of isocitrate lyase biosynthesis by hydroxylamine and hydrazine. 89 30

We have isolated a gene from Coprinus cinereus which cross-hybridises to the facA and acu-5 genes of Aspergillus nidulans and Neurospora crassa, respectively. These genes encode acetyl-CoA synthetase, an enzyme which is inducible by acetate and required for growth on acetate as sole carbon source. We have designated the C. cinereus gene acs-1 and have used transformation to demonstrate its functional homology to the ascomycete genes by complementation of an N. crassa acu-5 mutation. The acs-1 gene has never been identified by mutation; mutations leading to loss of acetyl-CoA synthetase function map to another gene, acu-1. Using Northern analyses we have shown that acu-1 has a regulatory function that is required for acetate-induced transcription of acs-1 and of another acetate utilisation gene, acu-7, the isocitrate lyase structural gene.
Mol Gen Genet 1992 Aug
PMID:The acu-1 gene of Coprinus cinereus is a regulatory gene required for induction of acetate utilisation enzymes. 135 39

Heterologous hybridisation of the Aspergillus nidulans structural gene for isocitrate lyase (acuD) to a lambda genomic library of Neurospora crassa identified a recombinant phage containing the hybridising sequence on an internal 9 kb EcoRI fragment. A restriction fragment length polymorphism (RFLP) enabled the fragment to be assigned to linkage group V (LG V), the location of the acetate-inducible isocitrate lyase, acu-3 of Neurospora. Functional ectopic complementation by co-transformation of an am-, acu- double mutant using independent plasmid clones, carrying the entire 9 kb EcoRI fragment (pICLG1) and the selectable marker am+ (NADP-glutamate dehydrogenase), demonstrated that the clone contains the entire acetate-inducible transcription unit. However, Northern analysis revealed two species of mRNA, only one of which was inducible on acetate. Native polyacrylamide gel electrophoresis separated two iso-enzymic activities, again only one of which was acetate-inducible and deficient in acu-3- mutants. Further hybridisation of the acu-3 gene probe to an electrophoretic karyotype of Neurospora crassa identified sequences in an additional linkage group as well as in LG V, as anticipated. The isozymes are therefore sequence-related.
Mol Gen Genet 1991 Oct
PMID:Isolation and expression of the acetate-inducible isocitrate lyase gene (acu-3) from Neurospora crassa: evidence for a second constitutive isozyme. 168 13

The temporal, nonconcerted development of activities of malate synthase (MS), isocitrate lyase (ICL), and catalase (Cat) was explored in more detail in maturing and germinated cotton (Gossypium hirsutum L.) seeds. RNA was extracted at six intervals beginning at 17 days post anthesis (DPA) through 72 hours post imbibition (HPI). In vitro translations revealed that mRNAs for each enzyme were translatable at all intervals. Enzyme activities and immunoselected proteins also were found at all intervals. Similar specific activities throughout maturation indicated that embryo cells were not accumulating inactive protein. The steady-state level of mRNAs encoding each enzyme exhibited different patterns of change during seed maturation, and each peaked at least 24 h before peak enzyme activities in germinated seeds. All three enzymes occur together as early as 17 DPA in a coordinate manner; however, the subsequent, nonconcerted increases in protein, activity, and mRNA for each enzyme indicate that developmental expression in cotton seed embryos is regulated in a noncoordinate fashion by as yet unidentified specific control mechanism(s).
Plant Mol Biol 1990 Feb
PMID:Development and regulation of three glyoxysomal enzymes during cotton seed maturation and growth. 171 13

Two different crystal forms of isocitrate lyase (ICL) from Escherichia coli have been grown following the chemical modification of the enzyme by either 3-bromopyruvate or ethyl mercuri thiosalicylate (EMTS), contrasting strongly with difficulties in obtaining ordered crystals of the native enzyme. Both crystal forms are obtained using the hanging drop method of vapour diffusion with ammonium sulphate as the precipitant. The crystals diffract well and X-ray photographs of the crystals have established that they are in space groups C222(1) and P3(1) (or its enantiomorph P3(2), respectively. Considerations of the values of Vm and measurements on the crystal density indicate that the asymmetric unit of both crystals contains four subunits.
J Mol Biol 1991 Jul 05
PMID:Use of chemical modification in the crystallization of isocitrate lyase from Escherichia coli. 206 12


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