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.

Photo-induction sexuée du pyrénomycète Nectria galligena: influence de la mycosporine sur le rapport des activités NADPM+-socitrate déshydrogénase/isocitrate lyase

1989 ◽  
Vol 67 (2) ◽  
pp. 447-450 ◽  
Author(s):  
B. Dehorter ◽  
L. Lacoste
Keyword(s):  
Isocitrate Dehydrogenase ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Glyoxylate Cycle ◽  
Nectria Galligena ◽  
Lyase Activity ◽  
Growth Of Fungi ◽  
The Glyoxylate Cycle

The activity of two enzymes of the tricarboxylic acid cycle (NADP+-isocitrate dehydrogenase, EC 1.1.1.42) and the glyoxylate cycle (isocitrate lyase, EC 4.1.3.1) were assayed in vitro to determine the effects of darkness, light, and mycosporin (P310) on sexual morphogenesis in Nectria galligena Bres. In the absence of mycosporin, high isocitrate lyase activity was associated with vegetative growth of fungi kept in the dark. In contrast, light-induced perithecial development and mycosporin biosynthesis could be correlated with high ratios of isocitrate dehydrogenase to isocitrate lyase activity. This was confirmed by the fact that when mycosporin was added to the nutrient medium with incubation in darkness, the fertility of the fungus was partially expressed and the activity of isocitrate lyase was significantly reduced. Thus this enzyme would be repressed in vivo by mycosporin. Because of its photomimetic role in sexual differentiation and regulation of intermediate metabolism, mycosporin appears to be a biochemical transmitter of light energy required for the formation of ascocarps.

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

1967 ◽  
Vol 47 (3) ◽  
pp. 199-209 ◽  
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.

scholarly journals Multiple Contributions of Peroxisomal Metabolic Function to Fungal Pathogenicity in Colletotrichum lagenarium

2006 ◽  
Vol 72 (9) ◽  
pp. 6345-6354 ◽  
Author(s):  
Makoto Asakura ◽  
Tetsuro Okuno ◽  
Yoshitaka Takano
Keyword(s):  
Host Plant ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Acetate Metabolism ◽  
Colletotrichum Lagenarium ◽  
Melanin Biosynthesis ◽  
Fungal Pathogenicity ◽  
Peroxisomal Targeting ◽  
The Glyoxylate Cycle ◽  
Host Invasion

ABSTRACT In Colletotrichum lagenarium, which is the causal agent of cucumber anthracnose, PEX6 is required for peroxisome biogenesis and appressorium-mediated infection. To verify the roles of peroxisome-associated metabolism in fungal pathogenicity, we isolated and functionally characterized ICL1 of C. lagenarium, which encodes isocitrate lyase involved in the glyoxylate cycle in peroxisomes. The icl1 mutants failed to utilize fatty acids and acetate for growth. Although Icl1 has no typical peroxisomal targeting signals, expression analysis of the GFP-Icl1 fusion protein indicated that Icl1 localizes in peroxisomes. These results indicate that the glyoxylate cycle that occurs inside the peroxisome is required for fatty acid and acetate metabolism for growth. Importantly, in contrast with the pex6 mutants that form nonmelanized appressoria, the icl1 mutants formed appressoria that were highly pigmented with melanin, suggesting that the glyoxylate cycle is not essential for melanin biosynthesis in appressoria. However, the icl1 mutants exhibited a severe reduction in virulence. Appressoria of the icl1 mutants failed to develop penetration hyphae in the host plant, suggesting that ICL1 is involved in host invasion. The addition of glucose partially restored virulence of the icl1 mutant. Heat shock treatment of the host plant also enabled the icl1 mutants to develop lesions, implying that the infection defect of the icl1 mutant is associated with plant defense. Together with the requirement of PEX6 for appressorial melanization, our findings suggest that peroxisomal metabolic pathways play functional roles in appressorial melanization and subsequent host invasion steps, and the latter step requires the glyoxylate cycle.

Effect of Leaf Senescence on Glyoxylate Cycle Enzyme Activities

1992 ◽  
Vol 19 (6) ◽  
pp. 723 ◽  
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.

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

2005 ◽  
Vol 37 (6) ◽  
pp. 406-414 ◽  
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.

scholarly journals Argentilactone Molecular Targets inParacoccidioides brasiliensisIdentified by Chemoproteomics

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Lívia do Carmo Silva ◽  
Sinji Borges Ferreira Tauhata ◽  
Lilian Cristiane Baeza ◽  
Cecília Maria Alves de Oliveira ◽  
Lucília Kato ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Acid Metabolism ◽  
Citrate Synthase ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Functional Categories ◽  
Content Type ◽  
Key Enzyme ◽  
Etiological Agents ◽  
The Glyoxylate Cycle

ABSTRACTParacoccidioidomycosis (PCM) is the cause of many deaths from systemic mycoses. The etiological agents of PCM belong to theParacoccidioidesgenus, which is restricted to Latin America. The infection is acquired through the inhalation of conidia that primarily lodge in the lungs and may disseminate to other organs and tissues. The treatment for PCM is commonly performed via the administration of antifungals such as amphotericin B, co-trimoxazole, and itraconazole. The antifungal toxicity and side effects, in addition to their long treatment times, have stimulated research for new bioactive compounds. Argentilactone is a compound that was isolated from the Brazilian savanna plantHyptis ovalifolia, and it has been suggested to be a potent antifungal, inhibiting the dimorphism ofP. brasiliensisand the enzymatic activity of isocitrate lyase, a key enzyme of the glyoxylate cycle. This work was developed due to the importance of elucidating the putative mode of action of argentilactone. The chemoproteomics approach via affinity chromatography was the methodology used to explore the interactions betweenP. brasiliensisproteins and argentilactone. A total of 109 proteins were identified and classified functionally. The most representative functional categories were related to amino acid metabolism, energy, and detoxification. Argentilactone inhibited the enzymatic activity of malate dehydrogenase, citrate synthase, and pyruvate dehydrogenase. Furthermore, argentilactone induces the production of reactive oxygen species and inhibits the biosynthesis of cell wall polymers.

scholarly journals Inhibitory Effects of Diketopiperazines from Marine-Derived Streptomyces puniceus on the Isocitrate Lyase of Candida albicans

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2111 ◽  
Author(s):  
Heegyu Kim ◽  
Ji-Yeon Hwang ◽  
Jongheon Shin ◽  
Ki-Bong Oh
Keyword(s):  
Candida Albicans ◽  
Cyclic Peptides ◽  
Inhibitory Concentration ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Malate Synthase ◽  
Wild Type ◽  
Inhibitory Effects ◽  
Reported Data ◽  
The Glyoxylate Cycle

The glyoxylate cycle is a sequence of anaplerotic reactions catalyzed by the key enzymes isocitrate lyase (ICL) and malate synthase, and plays an important role in the pathogenesis of microorganisms during infection. An icl-deletion mutant of Candida albicans exhibited reduced virulence in mice compared with the wild type. Five diketopiperazines, which are small and stable cyclic peptides, isolated from the marine-derived Streptomyces puniceus Act1085, were evaluated for their inhibitory effects on C. albicans ICL. The structures of these compounds were elucidated based on spectroscopic data and comparisons with previously reported data. Cyclo(L-Phe-L-Val) was identified as a potent ICL inhibitor, with a half maximal inhibitory concentration of 27 μg/mL. Based on the growth phenotype of the icl-deletion mutants and icl expression analyses, we demonstrated that cyclo(L-Phe-L-Val) inhibits the gene transcription of ICL in C. albicans under C2-carbon-utilizing conditions.

scholarly journals Flexible metabolism in Metarhizium anisopliae and Beauveria bassiana: role of the glyoxylate cycle during insect pathogenesis

Microbiology ◽  
2011 ◽  
Vol 157 (1) ◽  
pp. 199-208 ◽  
Author(s):  
Israel Enrique Padilla-Guerrero ◽  
Larissa Barelli ◽  
Gloria Angélica González-Hernández ◽  
Juan Carlos Torres-Guzmán ◽  
Michael J. Bidochka
Keyword(s):  
Beauveria Bassiana ◽  
Metarhizium Anisopliae ◽  
Citrate Synthase ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Pathogenic Fungi ◽  
Malate Synthase ◽  
Appressorium Formation ◽  
Insect Pathogenic Fungi ◽  
The Glyoxylate Cycle

Insect pathogenic fungi such as Metarhizium anisopliae and Beauveria bassiana have an increasing role in the control of agricultural insect pests and vectors of human diseases. Many of the virulence factors are well studied but less is known of the metabolism of these fungi during the course of insect infection or saprobic growth. Here, we assessed enzyme activity and gene expression in the central carbon metabolic pathway, including isocitrate dehydrogenase, aconitase, citrate synthase, malate synthase (MLS) and isocitrate lyase (ICL), with particular attention to the glyoxylate cycle when M. anisopliae and B. bassiana were grown under various conditions. We observed that ICL and MLS, glyoxylate cycle intermediates, were upregulated during growth on 2-carbon compounds (acetate and ethanol) as well as in insect haemolymph. We fused the promoter of the M. anisopliae ICL gene (Ma-icl) to a marker gene (mCherry) and showed that Ma-icl was upregulated when M. anisopliae was grown in the presence of acetate. Furthermore, Ma-icl was upregulated when fungi were engulfed by insect haemocytes as well as during appressorium formation. Addition of the ICL inhibitor 3-nitroproprionate delayed conidial germination and inhibited appressorium formation. These results show that these insect pathogenic fungi have a flexible metabolism that includes the glyoxylate cycle as an integral part of germination, pathogenesis and saprobic growth.

scholarly journals l-Malyl-Coenzyme A/β-Methylmalyl-Coenzyme A Lyase Is Involved in Acetate Assimilation of the Isocitrate Lyase-Negative Bacterium Rhodobacter capsulatus

2005 ◽  
Vol 187 (4) ◽  
pp. 1415-1425 ◽  
Author(s):  
Michael Meister ◽  
Stephan Saum ◽  
Birgit E. Alber ◽  
Georg Fuchs
Keyword(s):  
Rhodobacter Capsulatus ◽  
Coenzyme A ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Gene Clusters ◽  
Malate Synthase ◽  
Acetate Metabolism ◽  
Acetate Assimilation ◽  
Cell Extracts ◽  
Lyase Activity

ABSTRACT Cell extracts of Rhodobacter capsulatus grown on acetate contained an apparent malate synthase activity but lacked isocitrate lyase activity. Therefore, R. capsulatus cannot use the glyoxylate cycle for acetate assimilation, and a different pathway must exist. It is shown that the apparent malate synthase activity is due to the combination of a malyl-coenzyme A (CoA) lyase and a malyl-CoA-hydrolyzing enzyme. Malyl-CoA lyase activity was 20-fold up-regulated in acetate-grown cells versus glucose-grown cells. Malyl-CoA lyase was purified 250-fold with a recovery of 6%. The enzyme catalyzed not only the reversible condensation of glyoxylate and acetyl-CoA to l-malyl-CoA but also the reversible condensation of glyoxylate and propionyl-CoA to β-methylmalyl-CoA. Enzyme activity was stimulated by divalent ions with preference for Mn2+ and was inhibited by EDTA. The N-terminal amino acid sequence was determined, and a corresponding gene coding for a 34.2-kDa protein was identified and designated mcl1. The native molecular mass of the purified protein was 195 ± 20 kDa, indicating a homohexameric composition. A homologous mcl1 gene was found in the genomes of the isocitrate lyase-negative bacteria Rhodobacter sphaeroides and Rhodospirillum rubrum in similar genomic environments. For Streptomyces coelicolor and Methylobacterium extorquens, mcl1 homologs are located within gene clusters implicated in acetate metabolism. We therefore propose that l-malyl-CoA/β-methylmalyl-CoA lyase encoded by mcl1 is involved in acetate assimilation by R. capsulatus and possibly other glyoxylate cycle-negative bacteria.

scholarly journals 3′ Untranslated Region-Dependent Degradation of theaceAmRNA, Encoding the Glyoxylate Cycle Enzyme Isocitrate Lyase, by RNase E/G in Corynebacterium glutamicum

2012 ◽  
Vol 78 (24) ◽  
pp. 8753-8761 ◽  
Author(s):  
Tomoya Maeda ◽  
Masaaki Wachi
Keyword(s):  
Corynebacterium Glutamicum ◽  
Untranslated Region ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Rnase E ◽  
Wild Type ◽  
Knockout Mutant ◽  
Content Type ◽  
In The Wild ◽  
The Glyoxylate Cycle

ABSTRACTWe previously reported that theCorynebacterium glutamicumRNase E/G encoded by therneGgene (NCgl2281) is required for the 5′ maturation of 5S rRNA. In the search for the intracellular target RNAs of RNase E/G other than the 5S rRNA precursor, we detected that the amount of isocitrate lyase, an enzyme of the glyoxylate cycle, increased inrneGknockout mutant cells grown on sodium acetate as the sole carbon source. Rifampin chase experiments showed that the half-life of theaceAmRNA was about 4 times longer in therneGknockout mutant than in the wild type. Quantitative real-time PCR analysis also confirmed that the level ofaceAmRNA was approximately 3-fold higher in therneGknockout mutant strain than in the wild type. Such differences were not observed in other mRNAs encoding enzymes involved in acetate metabolism. Analysis by 3′ rapid amplification of cDNA ends suggested that RNase E/G cleaves theaceAmRNA at a single-stranded AU-rich region in the 3′ untranslated region (3′-UTR). ThelacZfusion assay showed that the 3′-UTR renderedlacZmRNA RNase E/G dependent. These findings indicate that RNase E/G is a novel regulator of the glyoxylate cycle inC. glutamicum.

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