scholarly journals Some aspects of carnitine metabolism in avocado (Persea americana) (Short Communication)

1973 ◽  
Vol 134 (2) ◽  
pp. 655-658 ◽  
Author(s):  
R. A. Panter ◽  
J. B. Mudd
Keyword(s):  
Short Communication ◽  
Higher Plants ◽  
Glyoxylate Cycle ◽  
Mitochondrial Fraction ◽  
Persea Americana ◽  
Succinate Oxidation ◽  
Two Systems ◽  
Carnitine Metabolism ◽  
The Glyoxylate Cycle

The fact that palmitoyl-l-carnitine is oxidized by avocado mitochondria at a rate comparable with that of succinate oxidation suggests that there are at least two systems for β-oxidation in higher plants. The carnitine-associated system is located in a mitochondrial fraction, whereas the glyoxylate-cycle-associated system is located in the glyoxysomes.

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.

Co-ordinate regulation of genes involved in storage lipid mobilization in Arabidopsis thaliana

2001 ◽  
Vol 29 (2) ◽  
pp. 283-286 ◽  
Author(s):  
E. L. Rylott ◽  
M. A. Hooks ◽  
I. A. Graham
Keyword(s):  
Arabidopsis Thaliana ◽  
Enzyme Activities ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Molecular Genetic ◽  
Regulation Of Gene Expression ◽  
Growth Period ◽  
Malate Synthase ◽  
The Glyoxylate Cycle

Molecular genetic approaches in the model plant Arabidopsis thaliana (ColO) are shedding new light on the role and control of the pathways associated with the mobilization of lipid reserves during oilseed germination and post-germinative growth. Numerous independent studies have reported on the expression of individual genes encoding enzymes from the three major pathways: β-oxidation, the glyoxylate cycle and gluconeogenesis. However, a single comprehensive study of representative genes and enzymes from the different pathways in a single plant species has not been done. Here we present results from Arabidopsis that demonstrate the co-ordinate regulation of gene expression and enzyme activities for the acyl-CoA oxidase- and 3-ketoacyl-CoA thiolasemediated steps of β-oxidation, the isocitrate lyase and malate synthase steps of the glyoxylate cycle and the phosphoenolpyruvate carboxykinase step of gluconeogenesis. The mRNA abundance and enzyme activities increase to a peak at stage 2, 48 h after the onset of seed germination, and decline thereafter either to undetectable levels (for malate synthase and isocitrate lyase) or low basal levels (for the genes of β-oxidation and gluconeogenesis). The co-ordinate induction of all these genes at the onset of germination raises the possibility that a global regulatory mechanism operates to induce the expression of genes associated with the mobilization of storage reserves during the heterotrophic growth period.

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

Regulation of the glyoxylate cycle inAcetobacter aceti

1977 ◽  
Vol 33 (1) ◽  
pp. 140-140
Author(s):  
S. Brunner ◽  
L. Ettlinger
Keyword(s):  
Glyoxylate Cycle ◽  
The Glyoxylate Cycle

Arabidopsis peroxisomal malate dehydrogenase functions in β-oxidation but not in the glyoxylate cycle

2007 ◽  
Vol 50 (3) ◽  
pp. 381-390 ◽  
Author(s):  
Itsara Pracharoenwattana ◽  
Johanna E. Cornah ◽  
Steven M. Smith
Keyword(s):  
Malate Dehydrogenase ◽  
Glyoxylate Cycle ◽  
The Glyoxylate Cycle

The glyoxylate cycle is required for fungal virulence

Nature ◽  
2001 ◽  
Vol 412 (6842) ◽  
pp. 83-86 ◽  
Author(s):  
Michael C. Lorenz ◽  
Gerald R. Fink
Keyword(s):  
Glyoxylate Cycle ◽  
Fungal Virulence ◽  
The Glyoxylate Cycle

Acetate metabolism in Escherichia coli

1978 ◽  
Vol 24 (2) ◽  
pp. 149-153 ◽  
Author(s):  
T. M. Lakshmi ◽  
Robert B. Helling
Keyword(s):  
Isocitrate Dehydrogenase ◽  
Citrate Synthase ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Acetate Metabolism ◽  
Wild Type ◽  
Intermediary Metabolites ◽  
Lyase Activity ◽  
Acetate Medium ◽  
The Glyoxylate Cycle

Levels of several intermediary metabolites were measured in cells grown in acetate medium in order to test the hypothesis that the glyoxylate cycle is repressed by phosphoenolpyruvate (PEP). Wild-type cells had less PEP than either isocitrate dehydrogenase – deficient cells (which had greater isocitrate lyase activity than the wild type) or isocitrate dehydrogenase – deficient, citrate synthase – deficient cells (which are poorly inducible). Thus induction of the glyoxylate cycle is more complicated than a simple function of PEP concentration. No correlation between enzyme activity and the level of oxaloacetate, pyruvate, or citrate was found either. Citrate was synthesized in citrate synthase – deficient mutants, possibly via citrate lyase.

scholarly journals The Apparent Malate Synthase Activity of Rhodobacter sphaeroides Is Due to Two Paralogous Enzymes, (3S)-Malyl-Coenzyme A (CoA)/β-Methylmalyl-CoA Lyase and (3S)- Malyl-CoA Thioesterase

2010 ◽  
Vol 192 (5) ◽  
pp. 1249-1258 ◽  
Author(s):  
Tobias J. Erb ◽  
Lena Frerichs-Revermann ◽  
Georg Fuchs ◽  
Birgit E. Alber
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Coenzyme A ◽  
Glyoxylate Cycle ◽  
Condensation Reaction ◽  
Malate Synthase ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Claisen Condensation ◽  
Enzyme Functions ◽  
The Glyoxylate Cycle

ABSTRACT Assimilation of acetyl coenzyme A (acetyl-CoA) is an essential process in many bacteria that proceeds via the glyoxylate cycle or the ethylmalonyl-CoA pathway. In both assimilation strategies, one of the final products is malate that is formed by the condensation of acetyl-CoA with glyoxylate. In the glyoxylate cycle this reaction is catalyzed by malate synthase, whereas in the ethylmalonyl-CoA pathway the reaction is separated into two proteins: malyl-CoA lyase, a well-known enzyme catalyzing the Claisen condensation of acetyl-CoA with glyoxylate and yielding malyl-CoA, and an unidentified malyl-CoA thioesterase that hydrolyzes malyl-CoA into malate and CoA. In this study the roles of Mcl1 and Mcl2, two malyl-CoA lyase homologs in Rhodobacter sphaeroides, were investigated by gene inactivation and biochemical studies. Mcl1 is a true (3S)-malyl-CoA lyase operating in the ethylmalonyl-CoA pathway. Notably, Mcl1 is a promiscuous enzyme and catalyzes not only the condensation of acetyl-CoA and glyoxylate but also the cleavage of β-methylmalyl-CoA into glyoxylate and propionyl-CoA during acetyl-CoA assimilation. In contrast, Mcl2 was shown to be the sought (3S)-malyl-CoA thioesterase in the ethylmalonyl-CoA pathway, which specifically hydrolyzes (3S)-malyl-CoA but does not use β-methylmalyl-CoA or catalyze a lyase or condensation reaction. The identification of Mcl2 as thioesterase extends the enzyme functions of malyl-CoA lyase homologs that have been known only as “Claisen condensation” enzymes so far. Mcl1 and Mcl2 are both related to malate synthase, an enzyme which catalyzes both a Claisen condensation and thioester hydrolysis reaction.

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