The malate synthase of Paracoccidioides brasiliensis Pb01 is required in the glyoxylate cycle and in the allantoin degradation pathway

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.

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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

Journal of Bacteriology ◽

10.1128/jb.01267-09 ◽

2010 ◽

Vol 192 (5) ◽

pp. 1249-1258 ◽

Cited By ~ 33

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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The fine structure and selected histochemistry of ungerminated basidiospores of Agrocybe acericola

Canadian Journal of Botany ◽

10.1139/b96-097 ◽

1996 ◽

Vol 74 (5) ◽

pp. 780-787 ◽

Cited By ~ 2

Author(s):

Donald G. Ruch ◽

Kiki Nurtjahja

Keyword(s):

Fine Structure ◽

Acid Phosphatase ◽

Glyoxylate Cycle ◽

Outer Wall ◽

Spore Wall ◽

Malate Synthase ◽

Marker Enzyme ◽

Wall Ultrastructure ◽

Membrane Bound ◽

The Glyoxylate Cycle

The basidiospore wall of Agrocybe acericola is composed of two distinct layers that are continuous around the spores. At the germ pore, the outer wall is very thin and the inner wall becomes thicker. The plasma membrane is appressed to the inner wall and lacks distinct invaginations. The protoplasm is densely packed with ribosomes. Spores contain very little lipid distributed at each end. Mitochondria are well defined and distributed throughout the cytoplasm. Spores are binucleate, with the two nuclei lying on a line nearly perpendicular to the long axis of the cell. Various sizes of single membrane-bound vacuoles are widely distributed in the cytoplasm. These vacuoles were shown to contain acid phosphatase, indicating lysosomal activity. Microbody-like organelles are observed, which are probably glyoxysomes, since assays of malate synthase, a marker enzyme of the glyoxylate cycle, are positive. Keywords: Agrocybe, spore wall ultrastructure, basidiospore ultrastructure, glyoxylate cycle, malate synthase, acid phosphatase.

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STUDIES ON RUMEN COLIFORM ORGANISMS: II. UTILIZATION OF ACETATE BY ESCHERICHIA COLI 64 ISOLATED FROM THE RUMEN FLUID OF A COW FED ALFALFA HAY

Canadian Journal of Animal Science ◽

10.4141/cjas67-031 ◽

1967 ◽

Vol 47 (3) ◽

pp. 199-209 ◽

Cited By ~ 1

Author(s):

C. R. Krishnamurti ◽

L. W. McElroy

Keyword(s):

Sodium Acetate ◽

Isocitrate Lyase ◽

Protein Hydrolysate ◽

Rumen Fluid ◽

Glyoxylate Cycle ◽

Malate Synthase ◽

E Coli ◽

Spectrophotometric Methods ◽

Acetate Medium ◽

The Glyoxylate Cycle

When cells of E. coli 64 were harvested in their exponential phase of growth in an acetate medium and incubated aerobically with sodium acetate-2-C14, about 33% of the label appeared in CO2 after 1 hr. Of the radioactivity in the cells, 72% was recovered in the protein hydrolysate, 8% in the nucleic acid, 6% in the lipid and 14% in the ethanol-soluble fractions. The radioactivity in the protein hydrolysate of cells incubated with sodium acetate-2-C14 was approximately 20 times that in the hydrolysate of cells incubated with C14O2 as the carbon source. By spectrophotometric methods, it was demonstrated that cell-free extracts of cells grown on acetate contained acetate kinase and phosphate acetyltransferase, plus, as demonstrated by spectrophotometric and isotopic methods, isocitrate lyase and malate synthase which are characteristic of the glyoxylate cycle. The enzymes of the glyoxylate cycle could not be demonstrated in cell-free extracts of E. coli 64 grown on glucose under either aerobic or anaerobic conditions. Possible functions that E. coli 64 may have in the maintenance of anaerobiosis in the rumen and utilization of acetate through the glyoxylate pathway are discussed.

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Changes in metabolic reserves and enzyme activities during zoospore motility and cyst germination in Phytophthora palmivora

Canadian Journal of Botany ◽

10.1139/b75-170 ◽

1975 ◽

Vol 53 (14) ◽

pp. 1411-1416 ◽

Cited By ~ 24

Author(s):

Christina E. Bimpong

Keyword(s):

Specific Activity ◽

Isocitrate Lyase ◽

Glyoxylate Cycle ◽

Krebs Cycle ◽

Malate Synthase ◽

Phytophthora Palmivora ◽

Germination Period ◽

Major Energy Source ◽

The Glyoxylate Cycle ◽

Cyst Germination

Lipids measured as acyl glycerides and free fatty acids provided the major energy source during a 6-h motile and a 2-h germination period in zoospores and cysts, respectively, of Phytophthora palmivora. Carbohydrates and proteins decreased slightly during the 6-h motile period but increased significantly during germination. Specific activity of isocitrate lyase decreased both during zoospore motility and cyst germination. Only trace amounts of malate synthase activity were detected in zoospores and cysts. The activities of both NAD-isocitrate and malate dehydrogenases increased slightly, while those of NADP-isocitrate and succinate dehydrogenases decreased during the 6-h motile period. During the 2-h germination period the specific activities of NAD- and NADP-isocitrate, malate, and succinate dehydrogenases increased. It appears that during the motile stage the glyoxylate cycle provided more metabolites for the Krebs cycle than it did during germination.

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Effect of Leaf Senescence on Glyoxylate Cycle Enzyme Activities

Functional Plant Biology ◽

10.1071/pp9920723 ◽

1992 ◽

Vol 19 (6) ◽

pp. 723 ◽

Cited By ~ 13

Author(s):

L Pistelli ◽

P Perata ◽

A Alpi

Keyword(s):

Malate Dehydrogenase ◽

Enzyme Activities ◽

Citrate Synthase ◽

Isocitrate Lyase ◽

Glyoxylate Cycle ◽

Malate Synthase ◽

Cycle Enzyme ◽

Hydroxypyruvate Reductase ◽

Foliar Senescence ◽

The Glyoxylate Cycle

In order to elucidate the metabolism of the peroxisomes during foliar senescence of leaf beet (Beta vulgaris L., var. cicla), peroxisomal activities have been determined at various stages of senescence. Catalase and hydroxypyruvate reductase activities decreased whereas those of the β-oxidation pathway and glyoxylate cycle enzymes increased at the same time. The increased activities of malate synthase, isocitrate lyase, malate dehydrogenase and citrate synthase indicate that the glyoxylate cycle might be activated during the foliar senescence of leaf beet.

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TheglcBlocus ofRhizobium leguminosarumVF39 encodes an arabinose-inducible malate synthase

Canadian Journal of Microbiology ◽

10.1139/w02-091 ◽

2002 ◽

Vol 48 (10) ◽

pp. 922-932 ◽

Cited By ~ 8

Author(s):

Alejandro García-de los Santos ◽

Alejandro Morales ◽

Laura Baldomá ◽

Scott R.D Clark ◽

Susana Brom ◽

...

Keyword(s):

Sinorhizobium Meliloti ◽

Rhizobium Leguminosarum ◽

Plant Cell Wall ◽

Glyoxylate Cycle ◽

Malate Synthase ◽

Mesorhizobium Loti ◽

Malate Synthase G ◽

Similar Genome Organization ◽

The Glyoxylate Cycle

In the course of a study conducted to isolate genes upregulated by plant cell wall sugars, we identified an arabinose-inducible locus from a transcriptional fusion library of Rhizobium leguminosarum VF39, carrying random insertions of the lacZ transposon Tn5B22. Sequence analysis of the locus disrupted by the transposon revealed a high similarity to uncharacterized malate synthase G genes from Sinorhizobium meliloti, Agrobacterium tumefaciens, and Mesorhizobium loti. This enzyme catalyzes the condensation of glyoxylate and acetyl-CoA to yield malate and CoA and is thought to be a component of the glyoxylate cycle, which allows microorganisms to grow on two carbon compounds. Enzyme assays showed that a functional malate synthase is encoded in the glcB gene of R. leguminosarum and that its expression is induced by arabinose, glycolate, and glyoxylate. An Escherichia coli aceB glcB mutant, complemented with the R. leguminosarum PCR-amplified gene, recovered malate synthase activity. A very similar genome organization of the loci containing malate synthase and flanking genes was observed in R. leguminosarum, S. meliloti, and A. tumefaciens. Pea plants inoculated with the glcB mutant or the wild-type strain showed no significant differences in nitrogen fixation. This is the first report regarding the characterization of a mutant in one of the glyoxylate cycle enzymes in the rhizobia.Key words: Rhizobium, malate synthase, glyoxylate cycle, arabinose metabolism.

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The localization of enzymes of intermediary metabolism in Astasia and Euglena

Biochemical Journal ◽

10.1042/bj1340607 ◽

1973 ◽

Vol 134 (2) ◽

pp. 607-616 ◽

Cited By ~ 13

Author(s):

Nicole Bégin-Heick

Keyword(s):

Succinate Dehydrogenase ◽

Isocitrate Lyase ◽

Tricarboxylic Acid Cycle ◽

Glyoxylate Cycle ◽

Intracellular Localization ◽

Tricarboxylic Acid ◽

Malate Synthase ◽

Particulate Fraction ◽

Acid Cycle ◽

The Glyoxylate Cycle

Results are presented on the intracellular localization of some of the enzymes of gluconeogenesis, of the tricarboxylic acid cycle and of related enzymes in Astasia and Euglena grown with various substrates. The results indicate the particulate nature of at least part of the malate synthase of Astasia and of part of the malate synthase and isocitrate lyase in Euglena. However, the presence of glyoxysomes (microbodies) in Astasia and Euglena is still open to question, since it has not, so far, been possible to separate the enzymes of the glyoxylate cycle from succinate dehydrogenase in the particulate fraction.

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Anaerobic Induction of Isocitrate Lyase and Malate Synthase in Submerged Rice Seedlings Indicates the Important Metabolic Role of the Glyoxylate Cycle

Acta Biochimica et Biophysica Sinica ◽

10.1111/j.1745-7270.2005.00060.x ◽

2005 ◽

Vol 37 (6) ◽

pp. 406-414 ◽

Cited By ~ 20

Author(s):

Ying Lu ◽

Yong-Rui Wu ◽

Bin Han

Keyword(s):

Isocitrate Lyase ◽

Tricarboxylic Acid Cycle ◽

Glyoxylate Cycle ◽

Fold Increase ◽

Malate Synthase ◽

Acetate Metabolism ◽

Activity Assay ◽

Rice Seedlings ◽

Metabolic Role ◽

The Glyoxylate Cycle

Abstract The glyoxylate cycle is a modified form of the tricarboxylic acid cycle that converts C2 compounds into C4 dicarboxylic acids at plant developmental stages. By studying submerged rice seedlings, we revealed the activation of the glyoxylate cycle by identifying the increased transcripts of mRNAs of the genes of isocitrate lyase (ICL) and malate synthase (MS), two characteristic enzymes of the glyoxylate cycle. Northern blot analysis showed that ICL and MS were activated in the prolonged anaerobic environment. The activity assay of pyruvate decarboxylase and ICL in the submerged seedlings indicated an 8.8-fold and 3.5-fold increase over that in the unsubmerged seedlings, respectively. The activity assay of acetyl-coenzyme A synthetase in the submerged seedlings indicated a 3-fold increase over that in the unsubmerged seedlings, which is important for initiating acetate metabolism. Consequently, we concluded that the glyoxylate cycle was involved in acetate metabolism under anaerobic conditions.

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