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[PMID]:28820943
[Au] Autor:Lee YV; Choi SB; Wahab HA; Choong YS
[Ad] Endereço:Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia , 11800 Minden, Penang, Malaysia.
[Ti] Título:Active Site Flexibility of Mycobacterium tuberculosis Isocitrate Lyase in Dimer Form.
[So] Source:J Chem Inf Model;57(9):2351-2357, 2017 Sep 25.
[Is] ISSN:1549-960X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Tuberculosis (TB) still remains a global threat due to the emergence of a drug-resistant strain. Instead of focusing on the drug target of active stage TB, we are highlighting the isocitrate lyase (ICL) at the dormant stage TB. ICL is one of the persistent factors for Mycobacterium tuberculosis (MTB) to survive during the dormant phase. In addition, the absence of ICL in human has made ICL a potential drug target for TB therapy. However, the dynamic details of ICL which could give insights to the ICL-ligand interaction have yet to be solved. Therefore, a series of ICL dimer dynamics studies through molecular dynamics simulation were performed in this work. The ICL active site entrance gate closure is contributed to by hydrogen bonding and electrostatic interactions with the C-terminal. Analysis suggested that the open-closed behavior of the ICL active site entrance depends on the type of ligand present in the active site. We also observed four residues (Ser91, Asp108, Asp153, and Cys191) which could possibly be the nucleophiles for nucleophilic attack on the cleavage of isocitrate at the C -C bond. We hope that the elucidation of ICL dynamics can benefit future works such as lead identification or antibody design against ICL for TB therapeutics.
[Mh] Termos MeSH primário: Domínio Catalítico
Isocitrato Liase/química
Simulação de Dinâmica Molecular
Mycobacterium tuberculosis/enzimologia
Multimerização Proteica
[Mh] Termos MeSH secundário: Isocitrato Liase/metabolismo
Estrutura Quaternária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
EC 4.1.3.1 (Isocitrate Lyase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171010
[Lr] Data última revisão:
171010
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170819
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jcim.7b00265


  2 / 611 MEDLINE  
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[PMID]:28610921
[Au] Autor:Shukla H; Shukla R; Sonkar A; Tripathi T
[Ad] Endereço:Molecular and Structural Biophysics Laboratory, Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India.
[Ti] Título:Alterations in conformational topology and interaction dynamics caused by L418A mutation leads to activity loss of Mycobacterium tuberculosis isocitrate lyase.
[So] Source:Biochem Biophys Res Commun;490(2):276-282, 2017 Aug 19.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mycobacterium tuberculosis isocitrate lyase (MtbICL) is a key enzyme of the glyoxylate cycle that catalyzes the cleavage of isocitrate to succinate and glyoxylate and is a potential antituberculosis drug target. The aim of this research was to explore the structural alterations induced by L418A point mutation that caused the loss of enzyme activity. In-depth structural analyses were carried out for understanding the influence of L418A mutation using techniques, viz. molecular dynamics, principal component analysis, time-dependent secondary structure, residue interaction network and molecular docking. Since L418A mutation site is structurally far from the active site, it cannot influence the binding of the substrate directly. Our results showed that collective motions, residual mobility, and flexibility of the enzyme increased upon mutation. The mutated residue changed the global conformational dynamics of the system along with the residue-residue interaction network, leading to a loss of the enzyme activity. The docking results suggest that L418A mutation influenced the binding interactions of the substrate with several residues in the active site of MtbICL. This study provides information on the structural dynamics of MtbICL and highlights the importance of residue level interactions in the protein. Thus, our results may provide significant guidance to the scientific community engaged in designing potent inhibitors targeting MtbICL.
[Mh] Termos MeSH primário: Alanina/genética
Isocitrato Liase/metabolismo
Lisina/genética
Simulação de Dinâmica Molecular
Mycobacterium tuberculosis/enzimologia
Mutação Puntual
[Mh] Termos MeSH secundário: Mycobacterium tuberculosis/metabolismo
Conformação Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
EC 4.1.3.1 (Isocitrate Lyase); K3Z4F929H6 (Lysine); OF5P57N2ZX (Alanine)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170615
[St] Status:MEDLINE


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[PMID]:28516845
[Au] Autor:Gründel M; Knoop H; Steuer R
[Ad] Endereço:2​Fachinstitut Theoretische Biologie (ITB), Institut für Biologie, Humboldt-Universität zu Berlin, Invalidenstraße 43, 10115 Berlin, Germany 1​Institut für Biologie, Humboldt-Universität zu Berlin, Chausseestr. 117, 10115 Berlin, Germany.
[Ti] Título:Activity and functional properties of the isocitrate lyase in the cyanobacterium Cyanothece sp. PCC 7424.
[So] Source:Microbiology;163(5):731-744, 2017 May.
[Is] ISSN:1465-2080
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Cyanobacteria are ubiquitous photoautotrophs that assimilate atmospheric CO2 as their main source of carbon. Several cyanobacteria are known to be facultative heterotrophs that are able to grow on diverse carbon sources. For selected strains, assimilation of organic acids and mixotrophic growth on acetate has been reported for decades. However, evidence for the existence of a functional glyoxylate shunt in cyanobacteria has long been contradictory and unclear. Genes coding for isocitrate lyase (ICL) and malate synthase were recently identified in two strains of the genus Cyanothece, and the existence of the complete glyoxylate shunt was verified in a strain of Chlorogloeopsis fritschii. Here, we report that the gene PCC7424_4054 of the strain Cyanothece sp. PCC 7424 encodes an enzymatically active protein that catalyses the reaction of ICL, an enzyme that is specific for the glyoxylate shunt. We demonstrate that ICL activity is induced under alternating day/night cycles and acetate-supplemented cultures exhibit enhanced growth. In contrast, growth under constant light did not result in any detectable ICL activity or enhanced growth of acetate-supplemented cultures. Furthermore, our results indicate that, despite the presence of a glyoxylate shunt, acetate does not support continued heterotrophic growth and cell proliferation. The functional validation of the ICL is supplemented with a bioinformatics analysis of enzymes that co-occur with the glyoxylate shunt. We hypothesize that the glyoxylate shunt in Cyanothece sp. PCC 7424, and possibly other nitrogen-fixing cyanobacteria, is an adaptation to a specific ecological niche and supports assimilation of nitrogen or organic compounds during the night phase.
[Mh] Termos MeSH primário: Acetatos/metabolismo
Cyanothece/enzimologia
Cyanothece/crescimento & desenvolvimento
Glioxilatos/metabolismo
Processos Heterotróficos/genética
Isocitrato Liase/genética
[Mh] Termos MeSH secundário: Proliferação Celular/fisiologia
Cyanothece/genética
Cyanothece/metabolismo
Malato Sintase/genética
Fotoperíodo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetates); 0 (Glyoxylates); EC 2.3.3.9 (Malate Synthase); EC 4.1.3.1 (Isocitrate Lyase); JQ39C92HH6 (glyoxylic acid)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171102
[Lr] Data última revisão:
171102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170519
[St] Status:MEDLINE
[do] DOI:10.1099/mic.0.000459


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[PMID]:28126757
[Au] Autor:Chen SJ; Wu X; Wadas B; Oh JH; Varshavsky A
[Ad] Endereço:Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
[Ti] Título:An N-end rule pathway that recognizes proline and destroys gluconeogenic enzymes.
[So] Source:Science;355(6323), 2017 01 27.
[Is] ISSN:1095-9203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cells synthesize glucose if deprived of it, and destroy gluconeogenic enzymes upon return to glucose-replete conditions. We found that the Gid4 subunit of the ubiquitin ligase GID in the yeast Saccharomyces cerevisiae targeted the gluconeogenic enzymes Fbp1, Icl1, and Mdh2 for degradation. Gid4 recognized the N-terminal proline (Pro) residue and the ~5-residue-long adjacent sequence motifs. Pck1, the fourth gluconeogenic enzyme, contains Pro at position 2; Gid4 directly or indirectly recognized Pro at position 2 of Pck1, contributing to its targeting. These and related results identified Gid4 as the recognition component of the GID-based proteolytic system termed the Pro/N-end rule pathway. Substrates of this pathway include gluconeogenic enzymes that bear either the N-terminal Pro residue or a Pro at position 2, together with adjacent sequence motifs.
[Mh] Termos MeSH primário: Gluconeogênese
Prolina/metabolismo
Proteólise
Proteínas de Saccharomyces cerevisiae/metabolismo
Saccharomyces cerevisiae/enzimologia
Proteínas de Transporte Vesicular/metabolismo
[Mh] Termos MeSH secundário: Frutose-Bifosfatase/química
Frutose-Bifosfatase/metabolismo
Glucose/deficiência
Isocitrato Liase/química
Isocitrato Liase/metabolismo
Malato Desidrogenase/química
Malato Desidrogenase/metabolismo
Prolina/química
Proteína Quinase C/química
Proteína Quinase C/metabolismo
Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/química
Proteínas de Saccharomyces cerevisiae/genética
Especificidade por Substrato
Proteínas de Transporte Vesicular/química
Proteínas de Transporte Vesicular/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Saccharomyces cerevisiae Proteins); 0 (VID24 protein, S cerevisiae); 0 (Vesicular Transport Proteins); 9DLQ4CIU6V (Proline); EC 1.1.1.37 (MDH2 protein, S cerevisiae); EC 1.1.1.37 (Malate Dehydrogenase); EC 2.7.11.13 (Protein Kinase C); EC 3.1.3.11 (FBP1 protein, S cerevisiae); EC 3.1.3.11 (Fructose-Bisphosphatase); EC 4.1.3.1 (ICL1 protein, S cerevisiae); EC 4.1.3.1 (Isocitrate Lyase); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171018
[Lr] Data última revisão:
171018
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170128
[St] Status:MEDLINE


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[PMID]:28041812
[Au] Autor:Ting SY; Ishola OA; Ahmed MA; Tabana YM; Dahham S; Agha MT; Musa SF; Muhammed R; Than LT; Sandai D
[Ad] Endereço:Infectomics Cluster, advanced medical and dental institute, universiti Sains Malaysia, Jln Tun Hamdan Sheikh Tahir, 13200 Bertam Penang, Malaysia.
[Ti] Título:Metabolic adaptation via regulated enzyme degradation in the pathogenic yeast Candida albicans.
[So] Source:J Mycol Med;27(1):98-108, 2017 Mar.
[Is] ISSN:1773-0449
[Cp] País de publicação:France
[La] Idioma:eng
[Ab] Resumo:The virulence of Candida albicans is dependent upon fitness attributes as well as virulence factors. These attributes include robust stress responses and metabolic flexibility. The assimilation of carbon sources is important for growth and essential for the establishment of infections by C. albicans. Previous studies showed that the C. albicans ICL1 genes, which encode the glyoxylate cycle enzymes isocitratelyase are required for growth on non-fermentable carbon sources such as lactate and oleic acid and were repressed by 2% glucose. In contrast to S. cerevsiae, the enzyme CaIcl1 was not destabilised by glucose, resulting with its metabolite remaining at high levels. Further glucose addition has caused CaIcl1 to lose its signal and mechanisms that trigger destabilization in response to glucose. Another purpose of this study was to test the stability of the Icl1 enzyme in response to the dietary sugars, fructose, and galactose. In the present study, the ICL1 mRNAs expression was quantified using Quantitative Real Time PCR, whereby the stability of protein was measured and quantified using Western blot and phosphoimager, and the replacing and cloning of ICL1 ORF by gene recombination and ubiquitin binding was conducted via co-immuno-precipitation. Following an analogous experimental approach, the analysis was repeated using S. cerevisiaeas a control. Both galactose and fructose were found to trigger the degradation of the ICL1 transcript in C. albicans. The Icl1 enzyme was stable following galactose addition but was degraded in response to fructose. C. albicans Icl1 (CaIcl1) was also subjected to fructose-accelerated degradation when expressed in S. cerevisiae, indicating that, although it lacks a ubiquitination site, CaIcl1 is sensitive to fructose-accelerated protein degradation. The addition of an ubiquitination site to CaIcl1 resulted in this enzyme becoming sensitive to galactose-accelerated degradation and increases its rate of degradation in the presence of fructose. It can be concluded that ubiquitin-independent pathways of fructose-accelerated enzyme degradation exist in C. albicans.
[Mh] Termos MeSH primário: Candida albicans/metabolismo
Candida albicans/patogenicidade
Metabolismo dos Carboidratos/fisiologia
Isocitrato Liase/metabolismo
Proteólise
Virulência/fisiologia
[Mh] Termos MeSH secundário: Adaptação Fisiológica/efeitos dos fármacos
Candida albicans/genética
Frutose/metabolismo
Frutose/farmacologia
Galactose/metabolismo
Galactose/farmacologia
Glioxilatos/metabolismo
Proteólise/efeitos dos fármacos
Saccharomyces cerevisiae/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
Ubiquitinação/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Glyoxylates); 0 (Saccharomyces cerevisiae Proteins); 30237-26-4 (Fructose); EC 4.1.3.1 (ICL1 protein, S cerevisiae); EC 4.1.3.1 (Isocitrate Lyase); JQ39C92HH6 (glyoxylic acid); X2RN3Q8DNE (Galactose)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171002
[Lr] Data última revisão:
171002
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170103
[St] Status:MEDLINE


  6 / 611 MEDLINE  
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[PMID]:27023679
[Au] Autor:Zhou M; Xie L; Yang Z; Zhou J; Xie J
[Ad] Endereço:a State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Institute of Modern Biopharmaceuticals, Ministry of Education, School of Life Sciences , Southwest University , Beibei, Chongqing 40
[Ti] Título:Lysine succinylation of Mycobacterium tuberculosis isocitrate lyase (ICL) fine-tunes the microbial resistance to antibiotics.
[So] Source:J Biomol Struct Dyn;35(5):1030-1041, 2017 Apr.
[Is] ISSN:1538-0254
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Lysine succinylation (Ksucc) is a newly identified protein posttranslational modification (PTM), which may play an important role in cellular physiology. However, the role of lysine succinylation in antibiotic resistance remains elusive. Isocitrate lyase (ICL) is crucial for broad-spectrum antibiotics tolerance in Mycobacterium tuberculosis (Mtb). We previously found that MtbICL (Rv0467) has at least three succinylated lysine residues, namely K189, K322, and K334.To explore the effect of succinylation on the activity of MtbICL, mutants' mimicry of the lysine succinylation were generated by site-directed mutagenesis. ICL-K189E mutant strain is more sensitive than the wild-type to rifampicin and streptomycin, but not isoniazid. For the in vitro activity of the purified isocitrate lyase, only K189E mutant showed significantly decreased activity. Crystal structure analysis showed that Lys189 Glu dramatically increased the pKa of Glu188 and decreased the pKa of Lys190, whereas had negligible effect on other residues within 5 Å as well as disruption of the electrostatic interaction between Lys189 and Glu182, which might prevent the closure of the active site loop and cause severe reduction of the enzyme activity. Considering the genetic, biochemical, and crystallographical evidences together, the succinylation of specific ICL residue can fine-tune the bacterial resistance to selected antibiotics. The decreased enzymatic activity resulting from the succinylation-changed electrostatic interaction might underlie this phenotype. This study provided the first insight into the link between lysine succinylation and antibiotic resistance.
[Mh] Termos MeSH primário: Antibacterianos/farmacologia
Farmacorresistência Bacteriana
Isocitrato Liase/química
Isocitrato Liase/metabolismo
Lisina/química
Lisina/metabolismo
Mycobacterium tuberculosis/efeitos dos fármacos
Mycobacterium tuberculosis/enzimologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Antituberculosos/farmacologia
Sequência Conservada
Ativação Enzimática
Evolução Molecular
Ordem dos Genes
Genoma Bacteriano
Genômica
Isocitrato Liase/genética
Viabilidade Microbiana/efeitos dos fármacos
Viabilidade Microbiana/genética
Modelos Moleculares
Mutação
Mycobacterium tuberculosis/genética
Conformação Proteica
Proteínas Recombinantes
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Antitubercular Agents); 0 (Recombinant Proteins); EC 4.1.3.1 (Isocitrate Lyase); K3Z4F929H6 (Lysine)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170407
[Lr] Data última revisão:
170407
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160330
[St] Status:MEDLINE
[do] DOI:10.1080/07391102.2016.1169219


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[PMID]:27590807
[Au] Autor:Nguyen TN; Yeh CW; Tsai PC; Lee K; Huang SL
[Ad] Endereço:Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan.
[Ti] Título:Transposon Mutagenesis Identifies Genes Critical for Growth of Pseudomonas nitroreducens TX1 on Octylphenol Polyethoxylates.
[So] Source:Appl Environ Microbiol;82(22):6584-6592, 2016 Nov 15.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Pseudomonas nitroreducens TX1 is of special interest because of its ability to utilize 0.05% to 20% octylphenol polyethoxylates (OPEO ) as a sole source of carbon. In this study, a library containing 30,000 Tn5-insertion mutants of the wild-type strain TX1 was constructed and screened for OPEO utilization, and 93 mutants were found to be unable to grow on OPEO In total, 42 separate disrupted genes were identified, and the proteins encoded by the genes were then classified into various categories, namely, information storage and processing (14.3%), cellular processes and signaling (28.6%), metabolism (35.7%), and unknown proteins (21.4%). The individual deletion of genes encoding isocitrate lyase (aceA), malate synthase (aceB), and glycolate dehydrogenase (glcE) was carried out, and the requirement for aceA and aceB but not glcE confirmed the role of the glyoxylate cycle in OPEO degradation. Furthermore, acetaldehyde dehydrogenase and acetyl-coenzyme A (acetyl-CoA) synthetase activity levels were 13.2- and 2.1-fold higher in TX1 cells grown on OPEO than in TX1 cells grown on succinate, respectively. Growth of the various mutants on different carbon sources was tested, and based on these findings, a mechanism involving exoscission to liberate acetaldehyde from the end of the OPEO chain during degradation is proposed for the breakdown of OPEO IMPORTANCE: Octylphenol polyethoxylates belong to the alkylphenol polyethoxylate (APEO ) nonionic surfactant family. Evidence based on the analysis of intermediate metabolites suggested that the primary biodegradation of APEO can be achieved by two possible pathways for the stepwise removal of the C ethoxylate units from the end of the chain. However, direct evidence for these hypotheses is still lacking. In this study, we described the use of transposon mutagenesis to identify genes critical to the catabolism of OPEO by P. nitroreducens TX1. The exoscission of the ethoxylate chain leading to the liberation of acetaldehyde is proposed. Isocitrate lyase and malate synthase in glyoxylate cycle are required in the catabolism of ethoxylated surfactants. Our findings also provide many gene candidates that may help elucidate the mechanisms in stress responses to ethoxylated surfactants by bacteria.
[Mh] Termos MeSH primário: Elementos de DNA Transponíveis
Mutagênese Insercional
Fenóis/metabolismo
Pseudomonas/crescimento & desenvolvimento
Pseudomonas/genética
[Mh] Termos MeSH secundário: Acetaldeído/metabolismo
Oxirredutases do Álcool/genética
Oxirredutases do Álcool/metabolismo
Aldeído Oxirredutases/metabolismo
Proteínas de Bactérias/genética
Proteínas de Bactérias/isolamento & purificação
Deleção de Genes
Isocitrato Liase/genética
Isocitrato Liase/metabolismo
Malato Sintase/genética
Malato Sintase/metabolismo
Pseudomonas/metabolismo
Ácido Succínico/metabolismo
Tensoativos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA Transposable Elements); 0 (Phenols); 0 (Surface-Active Agents); 0 (octylphenol); AB6MNQ6J6L (Succinic Acid); EC 1.1.- (Alcohol Oxidoreductases); EC 1.1.- (glycolic acid dehydrogenase); EC 1.2.- (Aldehyde Oxidoreductases); EC 1.2.1.5 (aldehyde dehydrogenase (NAD(P)+)); EC 2.3.3.9 (Malate Synthase); EC 4.1.3.1 (Isocitrate Lyase); GO1N1ZPR3B (Acetaldehyde)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160904
[St] Status:MEDLINE


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[PMID]:27450492
[Au] Autor:Famiani F; Paoletti A; Battistelli A; Moscatello S; Chen ZH; Leegood RC; Walker RP
[Ad] Endereço:Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Borgo XX Giugno, 74, 06121, Perugia, Italy. Electronic address: franco.famiani@unipg.it.
[Ti] Título:Phosphoenolpyruvate carboxykinase, pyruvate orthophosphate dikinase and isocitrate lyase in both tomato fruits and leaves, and in the flesh of peach and some other fruits.
[So] Source:J Plant Physiol;202:34-44, 2016 Sep 01.
[Is] ISSN:1618-1328
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:In this study the occurrence of a number of enzymes involved in gluconeogenesis was investigated in both tomato fruits and leaves during their development and senescence and in some other fruits. The enzymes studied were phosphoenolpyruvate carboxykinase (PEPCK), pyruvate orthophosphate dikinase (PPDK) and glyoxysomal isocitrate lyase (ICL). PPDK was detected in the ripe flesh of tomato, and much smaller amounts were detected in the flesh of both peach and pepper, whereas it was not detected (not present or at very low abundance) in the other fruits which were investigated (apricot, aubergine, blackberry, blueberry, cherry, grape, plum, raspberry and red current). By contrast PEPCK was present in the flesh of all the fruits investigated. Very small amounts of ICL were detected in ripe tomato flesh. PEPCK was present in the skin, flesh, locular gel and columella of tomato fruit, and in these its abundance increased greatly during ripening. PPDK showed a similar distribution, however, its abundance did not increase during ripening. PEPCK was not detected in tomato leaves at any stage of their development or senescence. The content of PPDK g(-1) fresh weight (FW) increased in tomato leaves as they matured, however, it declined during their senescence. In tomato leaves the content of ICL g(-1) FW increased until the mid-stage of development, then decreased as the leaf matured, and then increased during the latter stages of senescence. In the flesh of tomato fruits the contents of PPDK and PEPCK g(-1) FW decreased during senescence. The results suggest that in fruits other than tomato the bulk of any gluconeogenic flux proceeds via PEPCK, whereas in tomato both PEPCK and PPDK could potentially be utilised. Further, the results indicate that the conversion of pyruvate/acetyl-CoA to malate by the glyoxylate cycle, for which ICL is necessary, is not a major pathway utilised by gluconeogenesis in fruits under normal conditions of growth. Finally, the results contribute to our understanding of the role of several enzymes in the senescence of both leaves and fruits.
[Mh] Termos MeSH primário: Frutas/enzimologia
Isocitrato Liase/metabolismo
Lycopersicon esculentum/enzimologia
Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo
Folhas de Planta/enzimologia
Prunus persica/enzimologia
Piruvato Ortofosfato Diquinase/metabolismo
[Mh] Termos MeSH secundário: Gluconeogênese
Modelos Biológicos
Peptídeos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Peptides); EC 2.7.9.1 (Pyruvate, Orthophosphate Dikinase); EC 4.1.1.49 (Phosphoenolpyruvate Carboxykinase (ATP)); EC 4.1.3.1 (Isocitrate Lyase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170410
[Lr] Data última revisão:
170410
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160725
[St] Status:MEDLINE


  9 / 611 MEDLINE  
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[PMID]:27350614
[Au] Autor:Xu Z; Zhi Y; Dong J; Lin B; Ye D; Liu X
[Ad] Endereço:Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, The College of Biotechnology, Tianjin, 300457, P. R. China.
[Ti] Título:Requirement of the isocitrate lyase gene ICL1 for VPS41-mediated starvation response in Cryptococcus neoformans.
[So] Source:J Microbiol;54(7):487-91, 2016 Jul.
[Is] ISSN:1976-3794
[Cp] País de publicação:Korea (South)
[La] Idioma:eng
[Ab] Resumo:Cryptococcus neoformans is a major cause of fungal meningitis in individuals with impaired immunity. Our previous studies have shown that the VPS41 gene plays a critical role in the survival of Cryptococcus neoformans under nitrogen starvation; however, the molecular mechanisms underlying VPS41-mediated starvation response remain to be elucidated. In the present study, we show that, under nitrogen starvation, VPS41 strongly enhanced ICL1 expression in C. neoformans and that overexpression of ICL1 in the vps41 mutant dramatically suppressed its defects in starvation response due to the loss of VPS41 function. Moreover, targeted deletion of ICL1 resulted in a dramatic decline in viability of C. neoformans cells under nitrogen deprivation. Taken together, our data suggest a model in which VPS41 up-regulates ICL1 expression, directly or indirectly, to promote survival of C. neoformans under nitrogen starvation.
[Mh] Termos MeSH primário: Criptococose/microbiologia
Cryptococcus neoformans/enzimologia
Proteínas Fúngicas/metabolismo
Isocitrato Liase/metabolismo
Proteínas de Transporte Vesicular/metabolismo
[Mh] Termos MeSH secundário: Animais
Cryptococcus neoformans/genética
Cryptococcus neoformans/crescimento & desenvolvimento
Cryptococcus neoformans/fisiologia
Proteínas Fúngicas/genética
Regulação Fúngica da Expressão Gênica
Seres Humanos
Isocitrato Liase/genética
Camundongos
Viabilidade Microbiana
Nitrogênio/metabolismo
Proteínas de Transporte Vesicular/genética
Virulência
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Fungal Proteins); 0 (Vesicular Transport Proteins); EC 4.1.3.1 (Isocitrate Lyase); N762921K75 (Nitrogen)
[Em] Mês de entrada:1701
[Cu] Atualização por classe:171109
[Lr] Data última revisão:
171109
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160629
[St] Status:MEDLINE
[do] DOI:10.1007/s12275-016-6177-6


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[PMID]:27036942
[Au] Autor:Ahn S; Jung J; Jang IA; Madsen EL; Park W
[Ad] Endereço:From the Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea and.
[Ti] Título:Role of Glyoxylate Shunt in Oxidative Stress Response.
[So] Source:J Biol Chem;291(22):11928-38, 2016 May 27.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The glyoxylate shunt (GS) is a two-step metabolic pathway (isocitrate lyase, aceA; and malate synthase, glcB) that serves as an alternative to the tricarboxylic acid cycle. The GS bypasses the carbon dioxide-producing steps of the tricarboxylic acid cycle and is essential for acetate and fatty acid metabolism in bacteria. GS can be up-regulated under conditions of oxidative stress, antibiotic stress, and host infection, which implies that it plays important but poorly explored roles in stress defense and pathogenesis. In many bacterial species, including Pseudomonas aeruginosa, aceA and glcB are not in an operon, unlike in Escherichia coli In P. aeruginosa, we explored relationships between GS genes and growth, transcription profiles, and biofilm formation. Contrary to our expectations, deletion of aceA in P. aeruginosa improved cell growth under conditions of oxidative and antibiotic stress. Transcriptome data suggested that aceA mutants underwent a metabolic shift toward aerobic denitrification; this was supported by additional evidence, including up-regulation of denitrification-related genes, decreased oxygen consumption without lowering ATP yield, increased production of denitrification intermediates (NO and N2O), and increased cyanide resistance. The aceA mutants also produced a thicker exopolysaccharide layer; that is, a phenotype consistent with aerobic denitrification. A bioinformatic survey across known bacterial genomes showed that only microorganisms capable of aerobic metabolism possess the glyoxylate shunt. This trend is consistent with the hypothesis that the GS plays a previously unrecognized role in allowing bacteria to tolerate oxidative stress.
[Mh] Termos MeSH primário: Regulação Bacteriana da Expressão Gênica
Glioxilatos/metabolismo
Isocitrato Liase/metabolismo
Malato Sintase/metabolismo
Estresse Oxidativo
Pseudomonas aeruginosa/metabolismo
[Mh] Termos MeSH secundário: Acetatos/metabolismo
Biofilmes/crescimento & desenvolvimento
Biologia Computacional
Genoma Bacteriano
Isocitrato Liase/genética
Malato Sintase/genética
Redes e Vias Metabólicas
Consumo de Oxigênio
Pseudomonas aeruginosa/genética
Pseudomonas aeruginosa/crescimento & desenvolvimento
Transcriptoma
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Acetates); 0 (Glyoxylates); EC 2.3.3.9 (Malate Synthase); EC 4.1.3.1 (Isocitrate Lyase)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:170527
[Lr] Data última revisão:
170527
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160403
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M115.708149



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