The role of the glyoxylate cycle in the symbiotic fungus Tuber borchii: expression analysis and subcellular localization

2007 ◽  
Vol 52 (3-4) ◽  
pp. 159-170 ◽  
Author(s):  
Simona Abba’ ◽  
Raffaella Balestrini ◽  
Alessandra Benedetto ◽  
Hanspeter Rottensteiner ◽  
José Ramón De Lucas ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Expression Analysis ◽  
Glyoxylate Cycle ◽  
Tuber Borchii ◽  
Symbiotic Fungus ◽  
The Glyoxylate Cycle

scholarly journals Autophagic Machinery of Plant Peroxisomes

2019 ◽  
Vol 20 (19) ◽  
pp. 4754 ◽  
Author(s):  
Sławomir Borek ◽  
Szymon Stefaniak ◽  
Jan Śliwiński ◽  
Małgorzata Garnczarska ◽  
Małgorzata Pietrowska-Borek
Keyword(s):  
Molecular Mechanisms ◽  
Glyoxylate Cycle ◽  
Plant Cells ◽  
Physiological Role ◽  
Signal Molecules ◽  
Cell Organelles ◽  
Selective Degradation ◽  
Leaf Peroxisomes ◽  
The Glyoxylate Cycle

Peroxisomes are cell organelles that play an important role in plants in many physiological and developmental processes. The plant peroxisomes harbor enzymes of the β-oxidation of fatty acids and the glyoxylate cycle; photorespiration; detoxification of reactive oxygen and nitrogen species; as well as biosynthesis of hormones and signal molecules. The function of peroxisomes in plant cells changes during plant growth and development. They are transformed from organelles involved in storage lipid breakdown during seed germination and seedling growth into leaf peroxisomes involved in photorespiration in green parts of the plant. Additionally, intensive oxidative metabolism of peroxisomes causes damage to their components. Therefore, unnecessary or damaged peroxisomes are degraded by selective autophagy, called pexophagy. This is an important element of the quality control system of peroxisomes in plant cells. Despite the fact that the mechanism of pexophagy has already been described for yeasts and mammals, the molecular mechanisms by which plant cells recognize peroxisomes that will be degraded via pexophagy still remain unclear. It seems that a plant-specific mechanism exists for the selective degradation of peroxisomes. In this review, we describe the physiological role of pexophagy in plant cells and the current hypotheses concerning the mechanism of plant pexophagy.

The possible role of some enzymes in sclerotia formation in Aspergillus ochraceus

1983 ◽  
Vol 29 (6) ◽  
pp. 718-723 ◽  
Author(s):  
Nachman Paster ◽  
Ilan Chet
Keyword(s):  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Pentose Phosphate ◽  
Aspergillus Ochraceus ◽  
Phosphogluconate Dehydrogenase ◽  
Cycle Plays ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
The Glyoxylate Cycle

The role of some enzymes in sclerotia production by Aspergillus ochraceus was studied using a sclerotia-producing strain grown under conditions in which sclerotia production was either favoured or inhibited. In addition, a mutant strain incapable of producing sclerotia was used. No significant differences in patterns of soluble proteins, polyphenol oxidase, and esterases could be detected electrophoretically by gel electrophoresis, while the peroxidase pattern of both the sclerotia-producing strain and the mutant showed three bands as compared with two bands that appeared when sclerotia formation was inhibited. The activities of the tricarboxylic acid cycle enzymes, malate dehydrogenase and succinate dehydrogenase, and those of the pentose-phosphate pathway, glucose-6 phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, were almost identical in sclerotia- and nonsclerotia-producing mycelia. The activities of isocitrate lyase and malate synthetase, key enzymes of the glyoxylate cycle, and that of glyoxylate dehydrogenase which is related to this cycle were significantly reduced when sclerotia formation was inhibited either by methionine or by high levels of CO2. It is suggested that the glyoxylate cycle plays an important role in sclerotia formation in the fungus.

scholarly journals Aconitase: To Be or not to Be Inside Plant Glyoxysomes, That Is the Question

Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 162
Author(s):  
Luigi De Bellis ◽  
Andrea Luvisi ◽  
Amedeo Alpi
Keyword(s):  
Malate Dehydrogenase ◽  
Metabolic Pathways ◽  
Higher Plants ◽  
Glyoxylate Cycle ◽  
Genetic Research ◽  
Transcriptomic Analysis ◽  
Plant Biology ◽  
New Model ◽  
The Glyoxylate Cycle

After the discovery in 1967 of plant glyoxysomes, aconitase, one the five enzymes involved in the glyoxylate cycle, was thought to be present in the organelles, and although this was found not to be the case around 25 years ago, it is still suggested in some textbooks and recent scientific articles. Genetic research (including the study of mutants and transcriptomic analysis) is becoming increasingly important in plant biology, so metabolic pathways must be presented correctly to avoid misinterpretation and the dissemination of bad science. The focus of our study is therefore aconitase, from its first localization inside the glyoxysomes to its relocation. We also examine data concerning the role of the enzyme malate dehydrogenase in the glyoxylate cycle and data of the expression of aconitase genes in Arabidopsis and other selected higher plants. We then propose a new model concerning the interaction between glyoxysomes, mitochondria and cytosol in cotyledons or endosperm during the germination of oil-rich seeds.

scholarly journals Enzymes of the intermediary carbohydrate metabolism of Polyangium cellulosum

1985 ◽  
Vol 31 (12) ◽  
pp. 1142-1146 ◽  
Author(s):  
Renu Sarao ◽  
Howard D. McCurdy ◽  
Luciano Passador
Keyword(s):  
Carbohydrate Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Fold Increase ◽  
Pentose Phosphate ◽  
Acid Cycle ◽  
The Family ◽  
The Glyoxylate Cycle ◽  
Pentose Phosphate Shunt

Crude extracts of vegetative cells of the cellulolytic myxobacter Polyangium cellulosum contained significant levels of the enzymes of the tricarboxylic acid cycle and the glyoxylate cycle. Key enzymes of glycolysis and the pentose phosphate shunt were also detected. Specific activities of hexokinase and fructose- 1,6-diphosphate aldolase exhibited a 10-fold increase when the cells were grown in complex medium containing glucose. Cytochromes of a, b, and c type were demonstrated. By the use of a dispersly growing strain of P. cellulosum, its generation time was determined to be 22–24 h. This study suggests that the organism probably uses glycolysis and citric acid cycle for complete oxidation of glucose. The exact role of the glyoxylate cycle and pentose phosphate shunt cannot be deduced from this study. This is the first report on the study of intermediary carbohydrate metabolism in any member of the family Polyangiaceae.

The role of isocitrate lyase and the glyoxylate cycle in Escherichia coli growing under glucose limitation

2005 ◽  
Vol 156 (2) ◽  
pp. 178-183 ◽  
Author(s):  
Ram Prasad Maharjan ◽  
Pak-Lam Yu ◽  
Shona Seeto ◽  
Thomas Ferenci
Keyword(s):  
Escherichia Coli ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Glucose Limitation ◽  
The Glyoxylate Cycle

scholarly journals Major roles of isocitrate lyase and malate synthase in bacterial and fungal pathogenesis

Microbiology ◽  
2009 ◽  
Vol 155 (10) ◽  
pp. 3166-3175 ◽  
Author(s):  
M. F. Dunn ◽  
J. A. Ramírez-Trujillo ◽  
I. Hernández-Lucas
Keyword(s):  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Tca Cycle ◽  
Malate Synthase ◽  
The Tca Cycle ◽  
Plant Pathogenesis ◽  
Micro Organisms ◽  
The Glyoxylate Cycle ◽  
Anaplerotic Pathway

The glyoxylate cycle is an anaplerotic pathway of the tricarboxylic acid (TCA) cycle that allows growth on C2 compounds by bypassing the CO2-generating steps of the TCA cycle. The unique enzymes of this route are isocitrate lyase (ICL) and malate synthase (MS). ICL cleaves isocitrate to glyoxylate and succinate, and MS converts glyoxylate and acetyl-CoA to malate. The end products of the bypass can be used for gluconeogenesis and other biosynthetic processes. The glyoxylate cycle occurs in Eukarya, Bacteria and Archaea. Recent studies of ICL- and MS-deficient strains as well as proteomic and transcriptional analyses show that these enzymes are often important in human, animal and plant pathogenesis. These studies have extended our understanding of the metabolic pathways essential for the survival of pathogens inside the host and provide a more complete picture of the physiology of pathogenic micro-organisms. Hopefully, the recent knowledge generated about the role of the glyoxylate cycle in virulence can be used for the development of new vaccines, or specific inhibitors to combat bacterial and fungal diseases.

scholarly journals Life and Death in a Macrophage: Role of the Glyoxylate Cycle in Virulence

2002 ◽  
Vol 1 (5) ◽  
pp. 657-662 ◽  
Author(s):  
Michael C. Lorenz ◽  
Gerald R. Fink
Keyword(s):  
Glyoxylate Cycle ◽  
Life And Death ◽  
The Glyoxylate Cycle

The role of isocitrate lyase in the metabolism of algae

1966 ◽  
Vol 166 (1002) ◽  
pp. 11-29 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Soluble Fraction ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Tricarboxylic Acid ◽  
Chlamydomonas Reinhardii ◽  
The Glyoxylate Cycle ◽  
Do So

The incorporation of isotope from [2- 14 C]ethanol by cultures of the Brannon no. 1 strain of Chlorella vulgaris , growing on ethanol aerobically in the dark, was consistent with the operation of the tricarboxylic acid and glyoxylate cycles. Results obtained with [l- 14 C]acetate, added to similar cultures growing on glucose in the dark or on carbon dioxide in the light, indicated that the glyoxylate cycle did not function under these conditions. However, one of the key enzymes of this cycle, isocitrate lyase, was present in large amounts in extracts of this organism under all conditions of growth; in contrast, isocitrate lyase was inducibly formed by Chlamydomonas reinhardii prior to growth on acetate. No obvious dysfunction of the tricarboxylic acid cycle, which might necessitate the activity of isocitrate lyase during growth on other than C 2 -compounds, was detected in the Brannon no. 1 strain, nor were differences observed between the properties of the enzyme purified from cells grown on acetate and on glucose. But, whereas isocitrate lyase was wholly found in a soluble fraction of the organism after growth on glucose or on carbon dioxide, acetate-grown cells contained a major portion of their isocitrate lyase in a dense, particulate fraction. The Brannon no. 1 strain of Chlorella excreted labelled glycollate during growth in the dark on glucose in the presence of sodium [ 14 C]bicarbonate, but ceased to do so after transfer to acetate growth medium. The Pearsall’s strain of Chlorella , which does not form isocitrate lyase during growth on glucose, did not excrete labelled glycollate under these conditions. These results suggest that the Brannon no. 1 strain of Chlorella contained an active isocitrate lyase under all conditions of growth, but that this enzyme participates in the glyoxylate cycle only when it is incorporated into a particulate structure.

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