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

---

Query: EC:2.3.3.1 (citrate synthase)
4,488 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alfalfa is very sensitive to soil acidity and its yield and stand duration are compromised due to inhibited root growth and reduced nitrogen fixation caused by Al toxicity. Soil improvement by liming is expensive and only partially effective, and conventional plant breeding for Al tolerance has had limited success. Because tobacco and papaya plants overexpressing Pseudomonas aeruginosa citrate synthase (CS) have been reported to exhibit enhanced tolerance to Al, alfalfa was engineered by introducing the CS gene controlled by the Arabidopsis Act2 constitutive promoter or the tobacco RB7 root-specific promoter. Fifteen transgenic plants were assayed for exclusion of Al from the root tip, for internal citrate content, for growth in in vitro assays, or for shoot and root growth in either hydroponics or in soil assays. Overall, only the soil assays yielded consistent results. Based on the soil assays, two transgenic events were identified that were more aluminum-tolerant than the non-transgenic control, confirming that citrate synthase overexpression can be a useful tool to help achieve aluminum tolerance.
...
PMID:Bacterial citrate synthase expression and soil aluminum tolerance in transgenic alfalfa. 1830 42

Transgenic tomato (Solanum lycopersicum) plants, expressing a fragment of the mitochondrial citrate synthase gene in the antisense orientation and exhibiting mild reductions in the total cellular activity of this enzyme, displayed essentially no visible phenotypic alteration from the wild type. A more detailed physiological characterization, however, revealed that although these plants were characterized by relatively few changes in photosynthetic parameters they displayed a decreased relative flux through the tricarboxylic acid cycle and an increased rate of respiration. Furthermore, biochemical analyses revealed that the transformants exhibited considerably altered metabolism, being characterized by slight decreases in the levels of organic acids of the tricarboxylic acid cycle, photosynthetic pigments, and in a single line in protein content but increases in the levels of nitrate, several amino acids, and starch. We additionally determined the maximal catalytic activities of a wide range of enzymes of primary metabolism, performed targeted quantitative PCR analysis on all three isoforms of citrate synthase, and conducted a broader transcript profiling using the TOM1 microarray. Results from these studies confirmed that if the lines were somewhat impaired in nitrate assimilation, they were not severely affected by this, suggesting the presence of strategies by which metabolism is reprogrammed to compensate for this deficiency. The results are discussed in the context of carbon-nitrogen interaction and interorganellar coordination of metabolism.
...
PMID:Mild reductions in mitochondrial citrate synthase activity result in a compromised nitrate assimilation and reduced leaf pigmentation but have no effect on photosynthetic performance or growth. 1835 39

Male Atlantic salmon follow a conditional strategy, becoming either "combatants" that undertake a seaward migration and spend at least a year at sea or "sneakers" that remain in freshwater and mature as parr. A variety of physiological indices showed significant but small differences between the offspring of males that use these two reproductive tactics. Offspring fathered by anadromous male Atlantic salmon (Salmo salar L.) showed greater muscular development and muscle metabolic capacities but lower spontaneous movements than those fathered by mature male parr. At hatch and at maximum attainable wet weight (MAWW), offspring fathered by anadromous males had higher activities of mitochondrial (cytochrome C oxidase and citrate synthase) and glycolytic (lactate dehydrogenase [LDH]) enzymes than progeny of mature male parr. Enzymatic profiles of progeny of anadromous fathers also suggested greater nitrogen excretion capacity (glutamate dehydrogenase) and increased muscular development (creatine kinase and LDH) than in the progeny of mature parr. At MAWW, juveniles fathered by mature parr made considerably more spontaneous movements, presumably increasing their energy expenditures. For juveniles fathered by anadromous males, total cross-sectional areas of white and red muscle at hatch were higher due to the greater number of large-diameter fibers. We suggest that the slightly lower metabolic capacities and muscular development of alevins fathered by mature parr could reflect differences in energy partitioning during their dependence on vitellus. Greater spontaneous movements of offspring of mature male parr could favor feeding and growth after the resorption of the vitellus.
...
PMID:Paternal reproductive strategy influences metabolic capacities and muscle development of Atlantic salmon (Salmo salar L.) embryos. 1853 71

Effects of various nutritional and environmental factors on the accumulation of organic acids (mainly L-malic acid) by the filamentous fungus Aspergillus flavus were studied in a 16-L stirred fermentor. Improvement of the molar yield (moles acid produced per moles glucose consumed) of L-malic acid was obtained mainly by increasing the agitation rate (to 350 rpm) and the Fe(z+) ion concentration (to 12 mg/L) and by lowering the nitrogen (to 271 mg/L) and phosphate concentrations (to 1.5 mM) in the medium. These changes resulted in molar yields for L-malic acid and total C(4) acids (L-malic, succinic, and fumaric acids) of 128 and 155%, respectively. The high molar yields obtained (above 100%) are additional evidence for the operation of part of the reductive branch of the tricarboxylic acid cycle in L-malic acid accumulation by A. flavus. The fermentation conditions developed using the above mentioned factors and 9% CaCO(3) in the medium resulted in a high concentration (113 g/L L-malic acid from 120 g/L glucose utilized) and a high overall productivity (0.59 g/L h) of L-malic acid. These changes in acid accumulation coincide with increases in the activities of NAD(+)-malate dehydrogenase, fumarase, and citrate synthase.
...
PMID:Optimization of L-malic acid production by Aspergillus flavus in a stirred fermentor. 1859 43

ABSTRACT cDNA-amplified fragment length polymorphism (cDNA-AFLP) analysis was used to identify genes potentially involved in biological control, by strain Kh5 (Pichia anomala), of Botrytis cinerea, an important post-harvest pathogen on apples. Strain Kh5 was grown in yeast nitrogen base (YNB) plus glucose (G medium) or YNB plus cell walls of B. cinerea (B medium). Thirty-five primer pairs were used in AFLP amplifications, resulting in a total of more than 2,450 bands derived from the mRNA of strain Kh5 grown in B medium. Eighty-six bands (3.5%) corresponded to genes upregulated in B medium compared with G medium. Of these 86 bands, 28 were selected, cloned, sequenced, and subjected to real-time reverse transcription-polymerase chain reaction (RT-PCR) to confirm their differential expression. An appropriate housekeeping gene, G2, was selected and used to normalize the results of RT-PCR. Eleven genes presented an increased gene expression in the presence of B. cinerea cell walls (expression >1). Statistical analysis showed a significant increase for 5 of these 11 genes. The overexpressed genes show homologies to yeast genes with various functions, including beta-glucosidase, transmembrane transport, citrate synthase, and external amino acid sensing and transport. Some of these functions could be related to cell wall metabolism and potentially involved in mycoparasitic properties.
...
PMID:Identification of Differentially Expressed Genes by cDNA-Amplified Fragment Length Polymorphism in the Biocontrol Agent Pichia anomala (Strain Kh5). 1894 7

The effects through which an alfalfa protein hydrolysate (EM) possessing gibberellin- and auxin-like activity may promote plant nitrogen (N) nutrition have been investigated in Zea mays L. Treatment with 0.01 or 0.1 mg L(-1) EM for 48 h resulted in enhanced plant growth and leaf sugar accumulation. Concomitantly, the level of nitrates decreased, whereas total N percentage was unchanged. The activity of a number of enzymes involved in carbon (C) metabolism (malate dehydrogenase, MDH; isocitrate dehydrogenase, IDH; citrate synthase, CS) and N reduction and assimilation (nitrate reductase, NR; nitrite reductase, NiR; glutamine synthetase, GS; glutamate synthase, GOGAT; aspartate aminotransferase, AspAT) was significantly induced by EM supply to plants, and the transcription pattern of MDH, IDH, CS, and NR strongly correlated with data of enzyme activity. The transcript accumulation of asparagine synthetase (AS) was also induced by EM in the roots. The results suggest that EM might promote nitrogen assimilation in plants through a coordinate regulation of C and N metabolic pathways and open the way for further research on protein hydrolysates as a valid tool to improve N use efficiency and, as a consequence, to reduce the intensive use of inorganic N fertilizers in agriculture.
...
PMID:Effects of an alfalfa protein hydrolysate on the gene expression and activity of enzymes of the tricarboxylic acid (TCA) cycle and nitrogen metabolism in Zea mays L. 1905 64

The symbiotic nitrogen-fixing bacterium Sinorhizobium meliloti 1021 encodes only one predicted aconitase (AcnA) in its genome. AcnA has a significant degree of similarity with other bacterial aconitases that behave as dual proteins: enzymes and posttranscriptional regulators of gene expression. Similar to the case with these bacterial aconitases, AcnA activity was reversibly labile and was regained upon reconstitution with reduced iron. The aconitase promoter was active in root nodules. acnA mutants grew very poorly, had secondary mutations, and were quickly outgrown by pseudorevertants. The acnA gene was stably interrupted in a citrate synthase (gltA) null background, indicating that the intracellular accumulation of citrate may be deleterious for survival of strain 1021. No aconitase activity was detected in this mutant, suggesting that the acnA gene encodes the only functional aconitase of strain 1021. To uncover a function of AcnA beyond its catalytic role in the tricarboxylic acid cycle pathway, the gltA acnA double mutant was compared with the gltA single mutant for differences in motility, resistance to oxidative stress, nodulation, and growth on different substrates. However, no differences in any of these characteristics were found.
...
PMID:Deletion of citrate synthase restores growth of Sinorhizobium meliloti 1021 aconitase mutants. 1982 82

Methanococcoides burtonii is a cold-adapted methanogenic archaeon from Ace Lake in Antarctica. Methanol and methylamines are the only substrates it can use for carbon and energy. We carried out quantitative proteomics using iTRAQ of M. burtonii cells grown on different substrates (methanol in defined media or trimethylamine in complex media), using techniques that enriched for secreted and membrane proteins in addition to cytoplasmic proteins. By integrating proteomic data with the complete, manually annotated genome sequence of M. burtonii, we were able to gain new insight into methylotrophic metabolism and the effects of methanol on the cell. Metabolic processing of methanol and methylamines is initiated by methyltransferases specific for each substrate, with multiple paralogs for each of the methyltransferases (similar to other members of the Methanosarcinaceae). In M. burtonii, most methyltransferases appear to have distinct roles in the metabolism of methylated substrates, although two methylamine methyltransferases appear to be nonfunctional. One set of methyltransferases for trimethylamine catabolism appears to be membrane associated, potentially providing a mechanism to directly couple trimethylamine uptake to demethylation. Important roles were highlighted for citrate synthase, glutamine synthetase, acetyl-CoA decarbonylase/synthase, and pyruvate synthase in carbon and nitrogen metabolism during growth on methanol. M. burtonii had only a marginal response to the provision of exogenous amino acids (from yeast extract), indicating that it is predisposed to the endogenous synthesis of amino acids. Growth on methanol appeared to cause oxidative stress in the cell, possibly through the formation of reactive nonoxygen species and formaldehyde, and the oxidative inactivation of corrinoid proteins, with the cell responding by elevating the synthesis of universal stress (Usp) proteins, several nucleic acid binding proteins, and a serpin. In addition, changes in levels of cell envelope proteins were linked to counteracting the disruptive solvent effects of methanol on cell membranes. This is the first global proteomic study to examine the effects of different carbon sources on the growth of an obligately methylotrophic methanogen.
...
PMID:Global proteomic analysis of the insoluble, soluble, and supernatant fractions of the psychrophilic archaeon Methanococcoides burtonii. Part II: the effect of different methylated growth substrates. 1994 65

Metabolite profiles and activities of key enzymes in the metabolism of organic acids, nitrogen and amino acids were compared between chlorotic leaves and normal leaves of 'Honeycrisp' apple to understand how accumulation of non-structural carbohydrates affects the metabolism of organic acids, nitrogen and amino acids. Excessive accumulation of non-structural carbohydrates and much lower CO(2) assimilation were found in chlorotic leaves than in normal leaves, confirming feedback inhibition of photosynthesis in chlorotic leaves. Dark respiration and activities of several key enzymes in glycolysis and tricarboxylic acid (TCA) cycle, ATP-phosphofructokinase, pyruvate kinase, citrate synthase, aconitase and isocitrate dehydrogenase were significantly higher in chlorotic leaves than in normal leaves. However, concentrations of most organic acids including phosphoenolpyruvate (PEP), pyruvate, oxaloacetate, 2-oxoglutarate, malate and fumarate, and activities of key enzymes involved in the anapleurotic pathway including PEP carboxylase, NAD-malate dehydrogenase and NAD-malic enzyme were significantly lower in chlorotic leaves than in normal leaves. Concentrations of soluble proteins and most free amino acids were significantly lower in chlorotic leaves than in normal leaves. Activities of key enzymes in nitrogen assimilation and amino acid synthesis, including nitrate reductase, glutamine synthetase, ferredoxin and NADH-dependent glutamate synthase, and glutamate pyruvate transaminase were significantly lower in chlorotic leaves than in normal leaves. It was concluded that, in response to excessive accumulation of non-structural carbohydrates, glycolysis and TCA cycle were up-regulated to "consume" the excess carbon available, whereas the anapleurotic pathway, nitrogen assimilation and amino acid synthesis were down-regulated to reduce the overall rate of amino acid and protein synthesis.
...
PMID:Metabolism of organic acids, nitrogen and amino acids in chlorotic leaves of 'Honeycrisp' apple (Malus domestica Borkh) with excessive accumulation of carbohydrates. 2049 May 41

The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 is able to grow with cyanide as the sole nitrogen source. Membrane fractions from cells grown under cyanotrophic conditions catalysed the production of oxaloacetate from L-malate. Several enzymic activities of the tricarboxylic acid and glyoxylate cycles in association with the cyanide-insensitive respiratory pathway seem to be responsible for the oxaloacetate formation in vivo. Thus, in cyanide-grown cells, citrate synthase and isocitrate lyase activities were significantly higher than those observed with other nitrogen sources. Malate dehydrogenase activity was undetectable, but a malate:quinone oxidoreductase activity coupled to the cyanide-insensitive alternative oxidase was found in membrane fractions from cyanide-grown cells. Therefore, oxaloacetate production was linked to the cyanide-insensitive respiration in P. pseudoalcaligenes CECT5344. Cyanide and oxaloacetate reacted chemically inside the cells to produce a cyanohydrin (2-hydroxynitrile), which was further converted to ammonium. In addition to cyanide, strain CECT5344 was able to grow with several cyano derivatives, such as 2- and 3-hydroxynitriles. The specific system required for uptake and metabolization of cyanohydrins was induced by cyanide and by 2-hydroxynitriles, such as the cyanohydrins of oxaloacetate and 2-oxoglutarate.
...
PMID:Cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 involves a malate:quinone oxidoreductase and an associated cyanide-insensitive electron transfer chain. 2117 63


<< Previous 1 2 3 4 5 6 7 8 Next >>

---