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Sample records for carboxylase

  1. Molecular evolution of urea amidolyase and urea carboxylase in fungi

    OpenAIRE

    Harris Steven D; Nickerson Kenneth W; Strope Pooja K; Moriyama Etsuko N

    2011-01-01

    Abstract Background Urea amidolyase breaks down urea into ammonia and carbon dioxide in a two-step process, while another enzyme, urease, does this in a one step-process. Urea amidolyase has been found only in some fungal species among eukaryotes. It contains two major domains: the amidase and urea carboxylase domains. A shorter form of urea amidolyase is known as urea carboxylase and has no amidase domain. Eukaryotic urea carboxylase has been found only in several fungal species and green al...

  2. Molecular evolution of urea amidolyase and urea carboxylase in fungi

    Directory of Open Access Journals (Sweden)

    Harris Steven D

    2011-03-01

    Full Text Available Abstract Background Urea amidolyase breaks down urea into ammonia and carbon dioxide in a two-step process, while another enzyme, urease, does this in a one step-process. Urea amidolyase has been found only in some fungal species among eukaryotes. It contains two major domains: the amidase and urea carboxylase domains. A shorter form of urea amidolyase is known as urea carboxylase and has no amidase domain. Eukaryotic urea carboxylase has been found only in several fungal species and green algae. In order to elucidate the evolutionary origin of urea amidolyase and urea carboxylase, we studied the distribution of urea amidolyase, urea carboxylase, as well as other proteins including urease, across kingdoms. Results Among the 64 fungal species we examined, only those in two Ascomycota classes (Sordariomycetes and Saccharomycetes had the urea amidolyase sequences. Urea carboxylase was found in many but not all of the species in the phylum Basidiomycota and in the subphylum Pezizomycotina (phylum Ascomycota. It was completely absent from the class Saccharomycetes (phylum Ascomycota; subphylum Saccharomycotina. Four Sordariomycetes species we examined had both the urea carboxylase and the urea amidolyase sequences. Phylogenetic analysis showed that these two enzymes appeared to have gone through independent evolution since their bacterial origin. The amidase domain and the urea carboxylase domain sequences from fungal urea amidolyases clustered strongly together with the amidase and urea carboxylase sequences, respectively, from a small number of beta- and gammaproteobacteria. On the other hand, fungal urea carboxylase proteins clustered together with another copy of urea carboxylases distributed broadly among bacteria. The urease proteins were found in all the fungal species examined except for those of the subphylum Saccharomycotina. Conclusions We conclude that the urea amidolyase genes currently found only in fungi are the results of a horizontal

  3. The genes encoding the biotin carboxyl carrier protein and biotin carboxylase subunits of Bacillus subtilis acetyl coenzyme A carboxylase, the first enzyme of fatty acid synthesis.

    OpenAIRE

    P. Marini(GANIL); Li, S J; Gardiol, D; Cronan, J E; De Mendoza, D

    1995-01-01

    The genes encoding two subunits of acetyl coenzyme A carboxylase, biotin carboxyl carrier protein, and biotin carboxylase have been cloned from Bacillus subtilis. DNA sequencing and RNA blot hybridization studies indicated that the B. subtilis accB homolog which encodes biotin carboxyl carrier protein, is part of an operon that includes accC, the gene encoding the biotin carboxylase subunit of acetyl coenzyme A carboxylase.

  4. Interaction Between the Biotin Carboxyl Carrier Domain and the Biotin Carboxylase Domain in Pyruvate Carboxylase from Rhizobium etli†

    OpenAIRE

    Lietzan, Adam D.; Menefee, Ann L.; Zeczycki, Tonya N.; Kumar, Sudhanshu; Attwood, Paul V.; Wallace, John C.; Cleland, W. Wallace; Maurice, Martin St.

    2011-01-01

    Pyruvate carboxylase (PC) catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in mammalian tissues. To effect catalysis, the tethered biotin of PC must gain access to active sites in both the biotin carboxylase domain and the carboxyl transferase domain. Previous studies have demonstrated that a mutation of threonine 882 to alanine in PC from Rhizobium etli renders the carboxyl transferase domain inactive and favors the positioning of bioti...

  5. Structural analysis, plastid localization, and expression of the biotin carboxylase subunit of acetyl-coenzyme A carboxylase from tobacco.

    Science.gov (United States)

    Shorrosh, B S; Roesler, K R; Shintani, D; van de Loo, F J; Ohlrogge, J B

    1995-06-01

    Acetyl-coenzyme A carboxylase (ACCase, EC 6.4.1.2) catalyzes the synthesis of malonyl-coenzyme A, which is utilized in the plastid for de novo fatty acid synthesis and outside the plastid for a variety of reactions, including the synthesis of very long chain fatty acids and flavonoids. Recent evidence for both multifunctional and multisubunit ACCase isozymes in dicot plants has been obtained. We describe here the isolation of a tobacco (Nicotiana tabacum L. cv bright yellow 2 [NT1]) cDNA clone (E3) that encodes a 58.4-kD protein that shares 80% sequence similarity and 65% identity with the Anabaena biotin carboxylase subunit of ACCase. Similar to other biotin carboxylase subunits of acetyl-CoA carboxylase, the E3-encoded protein contains a putative ATP-binding motif but lacks a biotin-binding site (methionine-lysine-methionine or methionine-lysine-leucine). The deduced protein sequence contains a putative transit peptide whose function was confirmed by its ability to direct in vitro chloroplast uptake. The subcellular localization of this biotin carboxylase has also been confirmed to be plastidial by western blot analysis of pea (Pisum sativum), alfalfa (Medicago sativa L.), and castor (Ricinus communis L.) plastid preparations. Northern blot analysis indicates that the plastid biotin carboxylase transcripts are expressed at severalfold higher levels in castor seeds than in leaves. PMID:7610168

  6. Regulation of phosphoenolpyruvate carboxylase in PVYNTN-infected tobacco plants

    Czech Academy of Sciences Publication Activity Database

    Müller, Karel; Doubnerová, V.; Synková, Helena; Čeřovská, Noemi; Ryšlavá, H.

    2009-01-01

    Roč. 390, č. 3 (2009), s. 245-251. ISSN 1431-6730 R&D Projects: GA ČR GA206/03/0310; GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z50380511 Keywords : biotic stress * Nicotiana tabacum * phosphoenolpyruvate carboxylase (PEPC) Subject RIV: ED - Physiology Impact factor: 2.732, year: 2009

  7. Covalent dimerization of ribulose bisphosphate carboxylase subunits by UV radiation

    International Nuclear Information System (INIS)

    The effect of UV radiation (UV-A, UV-B and UV-C) on ribulose bisphosphate carboxylase from a variety of plant species was examined. The exposition of plant leaves or the pure enzyme to UV radiation produced a UV-dependent accumulation of a 65 kDa polypeptide (P65). Different approaches were utilized to elucidate the origin and structure of P65: electrophoretic and fluorographic analyses of 35S-labelled ribulose biphosphate carboxylase exposed to UV radiation and immunological experiments using antibodies specific for P65, for the large and small subunits of ribulose biphosphate carboxylase and for high-molecular-mass aggregates of the enzyme. These studies revealed that P65 is a dimer, formed by the covalent, non-disulphide linkage of one small subunit with one large subunit of ribulose biphosphate carboxylase. For short periods of time (<1 h), the amount of P65 formed increased with the duration of the exposure to the UV radiation and with the energy of the radiation applied. Prolonged exposure to UV radiation (1-6 h) resulted in the formation of high-molecular-mass aggregates of ribulose biphosphate carboxylase. Formation of P65 was shown to depend on the native state of the protein, was stimulated by inhibitors of enzyme activity, and was inhibited by activators of enzyme activity. A UV-independent accumulation of P65 was also achieved by the in vitro incubation of plant crude extracts. However, the UV-dependent and the UV-independent formation of P65 seemed to occur by distinct molecular mechanisms. The UV-dependent accumulation of P65 was immunologically detected in all species examined, including Lemna minor, Arum italicum, Brassica oleracea, Triticum aestivum, Zea mays, Pisum sativum and Phaseolus vulgaris, suggesting that it may constitute a universal response to UV radiation, common to all photosynthetic tissues. (Author)

  8. Covalent dimerization of ribulose bisphosphate carboxylase subunits by UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, R.M.B. [Universidade Tecnica, Lisbon (Portugal). Inst. Superior de Agronomia]|[Universidade Nova de Lisboa, Oeiras (Portugal). Instituto de Tecnologia Quimica e Biologica; Franco, E.; Teixeira, A.R.N. [Universidade Tecnica, Lisbon (Portugal). Inst. Superior de Agronomia

    1996-08-15

    The effect of UV radiation (UV-A, UV-B and UV-C) on ribulose bisphosphate carboxylase from a variety of plant species was examined. The exposition of plant leaves or the pure enzyme to UV radiation produced a UV-dependent accumulation of a 65 kDa polypeptide (P65). Different approaches were utilized to elucidate the origin and structure of P65: electrophoretic and fluorographic analyses of {sup 35}S-labelled ribulose biphosphate carboxylase exposed to UV radiation and immunological experiments using antibodies specific for P65, for the large and small subunits of ribulose biphosphate carboxylase and for high-molecular-mass aggregates of the enzyme. These studies revealed that P65 is a dimer, formed by the covalent, non-disulphide linkage of one small subunit with one large subunit of ribulose biphosphate carboxylase. For short periods of time (<1 h), the amount of P65 formed increased with the duration of the exposure to the UV radiation and with the energy of the radiation applied. Prolonged exposure to UV radiation (1-6 h) resulted in the formation of high-molecular-mass aggregates of ribulose biphosphate carboxylase. Formation of P65 was shown to depend on the native state of the protein, was stimulated by inhibitors of enzyme activity, and was inhibited by activators of enzyme activity. A UV-independent accumulation of P65 was also achieved by the in vitro incubation of plant crude extracts. However, the UV-dependent and the UV-independent formation of P65 seemed to occur by distinct molecular mechanisms. The UV-dependent accumulation of P65 was immunologically detected in all species examined, including Lemna minor, Arum italicum, Brassica oleracea, Triticum aestivum, Zea mays, Pisum sativum and Phaseolus vulgaris, suggesting that it may constitute a universal response to UV radiation, common to all photosynthetic tissues. (Author).

  9. Chemical Genetics of Acetyl-CoA Carboxylases

    Directory of Open Access Journals (Sweden)

    Xuyu Zu

    2013-01-01

    Full Text Available Chemical genetic studies on acetyl-CoA carboxylases (ACCs, rate-limiting enzymes in long chain fatty acid biosynthesis, have greatly advanced the understanding of their biochemistry and molecular biology and promoted the use of ACCs as targets for herbicides in agriculture and for development of drugs for diabetes, obesity and cancers. In mammals, ACCs have both biotin carboxylase (BC and carboxyltransferase (CT activity, catalyzing carboxylation of acetyl-CoA to malonyl-CoA. Several classes of small chemicals modulate ACC activity, including cellular metabolites, natural compounds, and chemically synthesized products. This article reviews chemical genetic studies of ACCs and the use of ACCs for targeted therapy of cancers.

  10. Mechanisms of Inhibition of Rhizobium etli Pyruvate Carboxylase by l-Aspartate

    OpenAIRE

    Sirithanakorn, Chaiyos; Adina-Zada, Abdussalam; Wallace, John C.; Jitrapakdee, Sarawut; Attwood, Paul V.

    2014-01-01

    l-Aspartate is a regulatory feedback inhibitor of the biotin-dependent enzyme pyruvate carboxylase in response to increased levels of tricarboxylic acid cycle intermediates. Detailed studies of l-aspartate inhibition of pyruvate carboxylase have been mainly confined to eukaryotic microbial enzymes, and aspects of its mode of action remain unclear. Here we examine its inhibition of the bacterial enzyme Rhizobium etli pyruvate carboxylase. Kinetic studies demonstrated that l-aspartate binds to ...

  11. The dynamic organization of fungal acetyl-CoA carboxylase

    Science.gov (United States)

    Hunkeler, Moritz; Stuttfeld, Edward; Hagmann, Anna; Imseng, Stefan; Maier, Timm

    2016-04-01

    Acetyl-CoA carboxylases (ACCs) catalyse the committed step in fatty-acid biosynthesis: the ATP-dependent carboxylation of acetyl-CoA to malonyl-CoA. They are important regulatory hubs for metabolic control and relevant drug targets for the treatment of the metabolic syndrome and cancer. Eukaryotic ACCs are single-chain multienzymes characterized by a large, non-catalytic central domain (CD), whose role in ACC regulation remains poorly characterized. Here we report the crystal structure of the yeast ACC CD, revealing a unique four-domain organization. A regulatory loop, which is phosphorylated at the key functional phosphorylation site of fungal ACC, wedges into a crevice between two domains of CD. Combining the yeast CD structure with intermediate and low-resolution data of larger fragments up to intact ACCs provides a comprehensive characterization of the dynamic fungal ACC architecture. In contrast to related carboxylases, large-scale conformational changes are required for substrate turnover, and are mediated by the CD under phosphorylation control.

  12. Studies on biotin dependent carboxylases and the properties of carboxybiotin

    International Nuclear Information System (INIS)

    Biotin dependent carboxyl-transfer reactions have been studied using biotin and pyruvate carboxylases. The pH profile for the Mg2+ and MgATP dependent carboxylation of biotin by bicarbonate shows that an enzymic base with a pK of 6.5 must be unprotonated for catalysis to occur. The pH profiles for the carboxyl-transfer reaction of pyruvate carboxylase have been obtained by studying the decarboxylation of oxalacetate stimulated by the presence of oxamate. Similarly, 13C and 2H isotope effects have been measured for the decarboxylation of oxalacetate by both enzymic and nonenzymic means. From these studies the authors can conclude that carboxyl-transfer between biotin and oxalacetate is at least partially rate-limiting and is not concerted with proton-transfer. The lack of any apparent enzymic acid-base catalyst (the V/K profile for oxalacetate is pH independent) suggests that proton transfer may occur directly between biotin and the carbanion formed when oxalacetate is decarboxylated. The pH profile for the nonenzymatic decarboxylation of carboxybiotin shows a plateau below pH 4 (k = 0.012 min-1 at 20C), and a lower plateau above pH 8 (k = 0.005 min-1 at 250C). A proton inventory at low pH is linear, while at high pH it is curved. These data suggest that two different mechanisms operate at high and low pH

  13. Biotin Responsive Multiple Carboxylase Deficiency Presenting as Diabetic Ketoacidosis.

    Directory of Open Access Journals (Sweden)

    Jia-Woei Hou

    2004-02-01

    Full Text Available Multiple carboxylase deficiency (MCD is a rare inherited metabolic disease of biotindependency due to deficiency of holocarboxylase synthetase (HCS or biotinidase deficiency.A 30-month-old female patient who presented with the initial features of diabeticketoacidosis (severe metabolic acidosis, ketosis, and hyperglycemia, lactic acidemia, moderatehyperammonemia, and generalized organic aciduria is described. Associated symptomsand signs included erythematous skin rashes, alopecia and developmental delay. The patientresponded dramatically to treatment with biotin (10 mg/day showing normalization of clinicalsymptoms and most biochemical abnormalities. Based on the urine organic profile bygas chromatography/ mass spectrometry (GC/MS, the diagnosis of MCD was made. A plasmatandem mass study confirmed this diagnosis. The biotinase activity in serum was normal,indicating that this was a rare case of late-onset HCS deficiency.

  14. Decreased renal vitamin K-dependent γ-glutamyl carboxylase activity in calcium oxalate calculi patients

    Institute of Scientific and Technical Information of China (English)

    陈俊汇; 刘继红; 章咏裳; 叶章群; 王少刚

    2003-01-01

    Objective To study the activity of vitamin K-dependent γ-glutamyl carboxylase in patients with calcium oxalate (CaOx) urolithiasis compared with healthy individuals and to assess its relationship to the renal calcium oxalate urolithiasis. Methods Renal parenchymas were harvested from urolithic patients and renal tumor patients undergoing nephrectomy. The renal carboxylase activity was evaluated as the radioactivity of [14C] labeled sodium bicarbonate in carboxylic reactions in vitro using β-liquid scintillation counting. Results Significantly reduced activity of renal vitamin K-dependent γ-glutamyl carboxylase was observed in the urolithic group as compared with normal controls (P<0.01). Conclusion It suggests that the reduced carboxylase activity observed in the urolithic patients may play an important role in the course of renal calcium oxalate urolithiasis.

  15. Effect of Pyruvate Carboxylase Overexpression on the Physiology of Corynebacterium glutamicum

    OpenAIRE

    Koffas, Mattheos A. G.; Jung, Gyoo Yeol; Aon, Juan C.; Stephanopoulos, Gregory

    2002-01-01

    Pyruvate carboxylase was recently sequenced in Corynebacterium glutamicum and shown to play an important role of anaplerosis in the central carbon metabolism and amino acid synthesis of these bacteria. In this study we investigate the effect of the overexpression of the gene for pyruvate carboxylase (pyc) on the physiology of C. glutamicum ATCC 21253 and ATCC 21799 grown on defined media with two different carbon sources, glucose and lactate. In general, the physiological effects of pyc overe...

  16. Crystallization and structure of a recombinant ribulose-1,5-bisphosphate carboxylase

    Science.gov (United States)

    Schneider, Gunter; Lindqvist, Ylva; Brändén, Carl-Ivar; Lorimer, George

    1988-07-01

    Ribulose-1,5-bisphosphate carboxylase/oxygenase is the key enzyme in photosynthetic carbon dioxide fixation and photorespiration. The dimeric carboxylase from the photosynthetic bacterium Rhodospirillum rubrum has been cloned and expressed in E. coli. The recombinant enzyme has been crystallized in a number of different crystal forms. The three-dimensional structure of the enzyme has been determined by X-ray crystallographic methods to 2.9Åresolution.

  17. Transcriptional activation of phosphoenolpyruvate carboxylase by phosphorus deficiency in tobacco.

    Science.gov (United States)

    Toyota, Kentaro; Koizumi, Nozomu; Sato, Fumihiko

    2003-03-01

    Phosphoenolpyruvate carboxylase (PEPC), which catalyses the carboxylation of phosphoenolpyruvate using HCO(3)(-) to generate oxaloacetic acid, is an important enzyme in the primary metabolism of plants. Although the PEPC genes (ppc) comprise only a small gene family, the function of each gene is not clear, except for roles in C(4) photosynthesis and CAM. Three PEPC genes (Nsppc1-3) from the C(3) plant Nicotiana sylvestris were used to investigate their roles and regulation in a C(3) plant, and their regulation by phosphorus depletion in particular. First, the induction of PEPC by phosphorus depletion was confirmed. Next, Nsppc1 was determined to be mainly responsive to phosphorus deficiency at the transcriptional level. Further studies using transgenic tobacco harbouring a chimeric gene consisting of the 2.0 kb promoter region of Nsppc1 and the beta-glucuronidase (GUS) reporter showed that PEPC is transcriptionally induced. It was also found that sucrose had a synergistic effect on the induction of PEPC by phosphorus deficiency. A series of transgenic tobacco containing 5'-deletion mutants of Nsppc1 promoter::GUS fusion revealed that the -539 to -442 bp Nsppc1 promoter region, relative to the translation start site, was necessary for the response to phosphorus deficiency. Gain-of-function analysis using a construct containing three tandem repeats of the -539 to -442 bp region confirmed that this region was sufficient to induce the phosphorus-deficiency response in tobacco. PMID:12598567

  18. Pyruvate carboxylase deficiency: An underestimated cause of lactic acidosis

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    F. Habarou

    2015-03-01

    Full Text Available Pyruvate carboxylase (PC is a biotin-containing mitochondrial enzyme that catalyzes the conversion of pyruvate to oxaloacetate, thereby being involved in gluconeogenesis and in energy production through replenishment of the tricarboxylic acid (TCA cycle with oxaloacetate. PC deficiency is a very rare metabolic disorder. We report on a new patient affected by the moderate form (the American type A. Diagnosis was nearly fortuitous, resulting from the revision of an initial diagnosis of mitochondrial complex IV (C IV defect. The patient presented with severe lactic acidosis and pronounced ketonuria, associated with lethargy at age 23 months. Intellectual disability was noted at this time. Amino acids in plasma and organic acids in urine did not show patterns of interest for the diagnostic work-up. In skin fibroblasts PC showed no detectable activity whereas biotinidase activity was normal. We had previously reported another patient with the severe form of PC deficiency and we show that she also had secondary C IV deficiency in fibroblasts. Different anaplerotic treatments in vivo and in vitro were tested using fibroblasts of both patients with 2 different types of PC deficiency, type A (patient 1 and type B (patient 2. Neither clinical nor biological effects in vivo and in vitro were observed using citrate, aspartate, oxoglutarate and bezafibrate. In conclusion, this case report suggests that the moderate form of PC deficiency may be underdiagnosed and illustrates the challenges raised by energetic disorders in terms of diagnostic work-up and therapeutical strategy even in a moderate form.

  19. Genes encoding biotin carboxylase subunit of acetyl-CoA carboxylase from Brassica napus and parental species: cloning, expression patterns, and evolution

    Science.gov (United States)

    Comparative genomics is a useful tool to investigate gene and genome evolution. Biotin carboxylase (BC), an important subunit of heteromeric ACCase that is a rate-limiting enzyme in fatty acid biosynthesis in dicots, catalyzes ATP, biotin-carboxyl-carrier protein and CO2 to form carboxybiotin-carbo...

  20. Characterization of three protein components required for functional reconstitution of the epoxide carboxylase multienzyme complex from Xanthobacter strain Py2.

    OpenAIRE

    Allen, J. R.; Ensign, S A

    1997-01-01

    Epoxide carboxylase from Xanthobacter strain Py2 catalyzes the reductant- and NAD+-dependent carboxylation of aliphatic epoxides to beta-keto acids. Epoxide carboxylase from Xanthobacter strain Py2 has been resolved from cell extracts by anion-exchange chromatography into three protein components, designated I, II, and III, that are obligately required for functional reconstitution of epoxide carboxylase activity. Component II has been purified to homogeneity on the basis of its ability to co...

  1. Increased expression of pyruvate carboxylase and biotin protein ligase increases lysine production in a biotin prototrophic Corynebacterium glutamicum strain

    DEFF Research Database (Denmark)

    Wang, Zhihao; Moslehi-Jenabian, Soloomeh; Solem, Christian;

    2015-01-01

    -CoA (or pimeloyl-Acyl Carrier Protein [ACP]) formation. Pyruvate carboxylase (pycA), a biotin-dependent enzyme needed for lysine biosynthesis and biotin ligase (birA), which is responsible for attaching biotin to pyruvate carboxylase, were overexpressed by replacing the native promoters with the strong...

  2. Characterization of phosphoenolpyruvate carboxylase from mature maize seeds: Properties of phosphorylated and dephosphorylated forms

    Czech Academy of Sciences Publication Activity Database

    Černý, M.; Doubnerová, V.; Müller, Karel; Ryšlavá, H.

    2010-01-01

    Roč. 92, č. 10 (2010), s. 1362-1370. ISSN 0300-9084 R&D Projects: GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z50380511 Keywords : Phosphoenolpyruvate carboxylase * Phosphorylation * Seed Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.787, year: 2010

  3. Isolation of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase from Leaves

    Science.gov (United States)

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a multi-functional enzyme that catalyzes the fixation of CO2 and O2 in photosynthesis and photorespiration, respectively. As the rate-limiting step in photosynthesis, improving the catalytic properties of Rubisco has long been viewed as a...

  4. Isolation, identification, and synthesis of 2-carboxyarabinitol 1-phosphate, a diurnal regulator of ribulase-bisphosphate carboxylase activity

    International Nuclear Information System (INIS)

    The diurnal change in activity of ribulose 1,5-bisphosphate (Rbu-1,5-P2) carboxylase [3-phospho-D-glycerate carboxy-lyase (dimerizing); EC 4.1.1.39] of leaves of Phaseolus vulgaris is regulated (in part) by mechanisms that control the level of an endogenous inhibitor that binds tightly to the activated (carbamoylated) form of Rbu-1,5-P2 carboxylase. This inhibitor was extracted from leaves and copurified with the Rbu-1,5-P2 carboxylase of the leaves. Further purification by ion-exchange chromatography, adsorption to purified Rbu-1,5-P2 carboxylase, barium precipitation, and HPLC separation yielded a phosphorylated compound that was a strong inhibitor of Rbu-1,5-P2 carboxylase. The compound was analyzed by GC/MS, 13C NMR, and 1H NMR and shown to be 2-carboxyarabinitol 1-phosphate [(2-C-phosphohydroxymethyl)-D-ribonic acid]. The structure of the isolated compound differs from the Rbu-1,5-P2 carboxylase transition-state analogue 2-carboxyarabinitol 1,5-bisphosphate only by the lack of the C-5 phosphate group. This difference results in a higher binding constant for the monophosphate compared with the bisphosphate. The less tightly bound compound acts in a light-dependent, reversible regulation of Rbu-1,5-P2 carboxylase activity in vivo

  5. Reaction of phosphoenolpyruvate carboxylase with (Z)-3-bromophosphoenolpyruvate and (Z)-3-fluorophosphoenolpyruvate

    International Nuclear Information System (INIS)

    (Z)-3-Bromophosphoenolpyruvate inactivates phosphoenolpyruvate carboxylase from maize in the presence of HCO3- and either Mg2+ or Mn2+. The inactivation rate follows saturation kinetics. Inactivation is slower in the presence of phospholactate or epoxymaleate, both of which are inhibitors of the enzyme, or dithiothreitol. Inactivation is completely prevented by the presence of lactate dehydrogenase and NADH, and 3-bromolactate is formed during this treatment. If the reaction is conducted by using HC18O3-, the inorganic phosphate produced contains 18O. This and other evidence indicate that phosphoenolpyruvate carboxylase catalyzes conversion of bromophosphoenolpyruvate into bromopyruvate by way of the usual carboxyphosphate-enolate intermediate, and bromopyruvate is the species responsible for enzyme inactivation. (Z)-3-fluorophosphoenolpyruvate is transformed by the enzyme into a 6:1 mixture of 3-fluoropyruvate and 3-fluorooxalacetate, presumably by the same mechanism. The enzyme is not inactivated during this treatment

  6. Reaction of phosphoenolpyruvate carboxylase with (Z)-3-bromophosphoenolpyruvate and (Z)-3-fluorophosphoenolpyruvate

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, E.; O' Laughlin, J.T.; O' Leary, M.H.

    1988-02-23

    (Z)-3-Bromophosphoenolpyruvate inactivates phosphoenolpyruvate carboxylase from maize in the presence of HCO/sub 3//sup -/ and either Mg/sup 2 +/ or Mn/sup 2 +/. The inactivation rate follows saturation kinetics. Inactivation is slower in the presence of phospholactate or epoxymaleate, both of which are inhibitors of the enzyme, or dithiothreitol. Inactivation is completely prevented by the presence of lactate dehydrogenase and NADH, and 3-bromolactate is formed during this treatment. If the reaction is conducted by using HC/sup 18/O/sub 3//sup -/, the inorganic phosphate produced contains /sup 18/O. This and other evidence indicate that phosphoenolpyruvate carboxylase catalyzes conversion of bromophosphoenolpyruvate into bromopyruvate by way of the usual carboxyphosphate-enolate intermediate, and bromopyruvate is the species responsible for enzyme inactivation. (Z)-3-fluorophosphoenolpyruvate is transformed by the enzyme into a 6:1 mixture of 3-fluoropyruvate and 3-fluorooxalacetate, presumably by the same mechanism. The enzyme is not inactivated during this treatment.

  7. Inhibition of acetyl-CoA carboxylase by cystamine may mediate the hypotriglyceridemic activity of pantethine.

    Science.gov (United States)

    McCarty, M F

    2001-03-01

    Pantethine is a versatile and well-tolerated hypolipidemic agent whose efficacy in this regard appears to be mediated by its catabolic product cystamine, a nucleophile which avidly attacks disulfide groups. An overview of pantethine research suggests that the hypotriglyceridemic activity of pantethine reflects cystamine-mediated inhibition of the hepatic acetyl-CoA carboxylase, which can be expected to activate hepatic fatty acid oxidation. Inhibition of HMG-CoA reductase as well as a more distal enzyme in the cholesterol synthetic pathway may account for pantethine's hypocholesterolemic effects. If pantethine does indeed effectively inhibit hepatic acetyl-CoA carboxylase, it may have adjuvant utility in the hepatothermic therapy of obesity. As a safe and effective compound of natural origin, pantethine merits broader use in the management of hyperlipidemias. PMID:11359352

  8. Vitamin K-dependent carboxylase: possible role of the substrate "propeptide" as an intracellular recognition site.

    Science.gov (United States)

    Suttie, J W; Hoskins, J A; Engelke, J; Hopfgartner, A; Ehrlich, H; Bang, N U; Belagaje, R M; Schoner, B; Long, G L

    1987-01-01

    The liver microsomal vitamin K-dependent carboxylase catalyzes the posttranslational conversion of specific glutamate residues to gamma-carboxyglutamate residues in a limited number of proteins. A number of these proteins have been shown to contain a homologous basic amino acid-rich "propeptide" between the leader sequence and the amino terminus of the mature protein. Plasmids encoding protein C, a vitamin K-dependent protein, containing or lacking a propeptide region were constructed and the protein was expressed in Escherichia coli. The protein products were assayed as substrates in an in vitro vitamin K-dependent carboxylase system. Only proteins containing a propeptide region were substrates for the enzyme. These data support the hypothesis that this sequence of the primary gene product is an important recognition site for this processing enzyme. PMID:3543932

  9. Expression, purification and crystallization of an archaeal-type phosphoenolpyruvate carboxylase

    International Nuclear Information System (INIS)

    The expression, purification, crystallization and preliminary diffraction analysis of an archaeal-type phosphoenolpyruvate carboxylase are described. Complete highly redundant X-ray data have been measured from a crystal diffracting to 3.13 Å resolution. An archaeal-type phosphoenolpyruvate carboxylase (PepcA) from Clostridium perfringens has been expressed in Escherichia coli in a soluble form with an amino-terminal His tag. The recombinant protein is enzymatically active and two crystal forms have been obtained. Complete diffraction data extending to 3.13 Å resolution have been measured from a crystal soaked in KAu(CN)2, using radiation at a wavelength just above the Au LIII edge. The asymmetric unit contains two tetramers of PepcA

  10. Crystal Structures of Human and Staphylococcus aureus Pyruvate Carboxylase and Molecular Insights into the Carboxyltransfer Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Xiang,S.; Tong, L.

    2008-01-01

    Pyruvate carboxylase (PC) catalyzes the biotin-dependent production of oxaloacetate and has important roles in gluconeogenesis, lipogenesis, insulin secretion and other cellular processes. PC contains the biotin carboxylase (BC), carboxyltransferase (CT) and biotin-carboxyl carrier protein (BCCP) domains. We report here the crystal structures at 2.8-Angstroms resolution of full-length PC from Staphylococcus aureus and the C-terminal region (missing only the BC domain) of human PC. A conserved tetrameric association is observed for both enzymes, and our structural and mutagenesis studies reveal a previously uncharacterized domain, the PC tetramerization (PT) domain, which is important for oligomerization. A BCCP domain is located in the active site of the CT domain, providing the first molecular insights into how biotin participates in the carboxyltransfer reaction. There are dramatic differences in domain positions in the monomer and the organization of the tetramer between these enzymes and the PC from Rhizobium etli.

  11. Crystal structure of the 500-kDa yeast acetyl-CoA carboxylase holoenzyme dimer.

    Science.gov (United States)

    Wei, Jia; Tong, Liang

    2015-10-29

    Acetyl-CoA carboxylase (ACC) has crucial roles in fatty acid metabolism and is an attractive target for drug discovery against diabetes, cancer and other diseases. Saccharomyces cerevisiae ACC (ScACC) is crucial for the production of very-long-chain fatty acids and the maintenance of the nuclear envelope. ACC contains biotin carboxylase (BC) and carboxyltransferase (CT) activities, and its biotin is linked covalently to the biotin carboxyl carrier protein (BCCP). Most eukaryotic ACCs are 250-kilodalton (kDa), multi-domain enzymes and function as homodimers and higher oligomers. They contain a unique, 80-kDa central region that shares no homology with other proteins. Although the structures of the BC, CT and BCCP domains and other biotin-dependent carboxylase holoenzymes are known, there is currently no structural information on the ACC holoenzyme. Here we report the crystal structure of the full-length, 500-kDa holoenzyme dimer of ScACC. The structure is remarkably different from that of the other biotin-dependent carboxylases. The central region contains five domains and is important for positioning the BC and CT domains for catalysis. The structure unexpectedly reveals a dimer of the BC domain and extensive conformational differences compared to the structure of the BC domain alone, which is a monomer. These structural changes reveal why the BC domain alone is catalytically inactive and define the molecular mechanism for the inhibition of eukaryotic ACC by the natural product soraphen A and by phosphorylation of a Ser residue just before the BC domain core in mammalian ACC. The BC and CT active sites are separated by 80 Å, and the entire BCCP domain must translocate during catalysis. PMID:26458104

  12. Vitamin K-dependent carboxylase: possible role of the substrate "propeptide" as an intracellular recognition site.

    OpenAIRE

    Suttie, J W; Hoskins, J A; Engelke, J; Hopfgartner, A; Ehrlich, H.; Bang, N U; Belagaje, R M; Schoner, B; Long, G L

    1987-01-01

    The liver microsomal vitamin K-dependent carboxylase catalyzes the posttranslational conversion of specific glutamate residues to gamma-carboxyglutamate residues in a limited number of proteins. A number of these proteins have been shown to contain a homologous basic amino acid-rich "propeptide" between the leader sequence and the amino terminus of the mature protein. Plasmids encoding protein C, a vitamin K-dependent protein, containing or lacking a propeptide region were constructed and the...

  13. Heterogeneity of holocarboxylase synthetase in patients with biotin-responsive multiple carboxylase deficiency.

    OpenAIRE

    Burri, B J; Sweetman, L.; Nyhan, W L

    1985-01-01

    Holocarboxylase synthetase activity has been determined in fibroblasts of seven patients with the neonatal form of biotin-responsive multiple carboxylase deficiency. The normal Km for biotin was 15 +/- 3 nmol/l, while in the patients the values ranged from 48 to 1,062 nmol/l. The mean maximum velocity was 27% of normal. Differences among the values obtained for the Km for biotin and the heat stability of holocarboxylase synthetase suggested that the patients studied represented at least four ...

  14. Deregulation of Feedback Inhibition of Phosphoenolpyruvate Carboxylase for Improved Lysine Production in Corynebacterium glutamicum

    OpenAIRE

    Chen, Zhen; Bommareddy, Rajesh Reddy; Frank, Doinita; Rappert, Sugima; Zeng, An-Ping

    2014-01-01

    Allosteric regulation of phosphoenolpyruvate carboxylase (PEPC) controls the metabolic flux distribution of anaplerotic pathways. In this study, the feedback inhibition of Corynebacterium glutamicum PEPC was rationally deregulated, and its effect on metabolic flux redistribution was evaluated. Based on rational protein design, six PEPC mutants were designed, and all of them showed significantly reduced sensitivity toward aspartate and malate inhibition. Introducing one of the point mutations ...

  15. Effect of Vitamin K-dependent Protein Precursor Propeptide, Vitamin K Hydroquinone, and Glutamate Substrate Binding on the Structure and Function of γ-Glutamyl Carboxylase*

    OpenAIRE

    Higgins-Gruber, Shannon L.; Mutucumarana, Vasantha P.; Lin, Pen-Jen; Jorgenson, James W.; Stafford, Darrel W.; Straight, David L.

    2010-01-01

    The γ-glutamyl carboxylase utilizes four substrates to catalyze carboxylation of certain glutamic acid residues in vitamin K-dependent proteins. How the enzyme brings the substrates together to promote catalysis is an important question in understanding the structure and function of this enzyme. The propeptide is the primary binding site of the vitamin K-dependent proteins to carboxylase. It is also an effector of carboxylase activity. We tested the hypothesis that binding of substrates cause...

  16. Partitioning of Nitrogen among Ribulose-1,5-bisphosphate Carboxylase/Oxygenase, Phosphoenolpyruvate Carboxylase, and Pyruvate Orthophosphate Dikinase as Related to Biomass Productivity in Maize Seedlings.

    Science.gov (United States)

    Sugiyama, T; Mizuno, M; Hayashi, M

    1984-07-01

    Maize (Zea mays L. cv Golden Cross Bantam T51) seedlings were grown under full sunlight or 50% sunlight in a temperature-controlled glasshouse at the temperatures of near optimum (30/25 degrees C) and suboptimum (17/13 degrees C) with seven levels of nitrate-N (0.4 to 12 millimolars). The contents of phosphoenolpyruvate carboxylase (PEPC), pyruvate orthophosphate dikinase (PPD), and ribulose-1,5-P(2) carboxylase/oxygenase (RuBisCO) were immunochemically determined for each treatment with rabbit antibodies raised against the respective maize leaf proteins (anti-PEPC and anti-PPD) or spinach leaf protein (anti-RuBisCO). The content of each enzymic protein increased with increasing N and raised under reduced temperature. The positive effect of light intensity on their contents was evident only at near optimal temperature. The relative increase in PEPC and PPD content with increasing N was significantly greater than that of RuBisCO irrespective of growth conditions. These enzymic proteins comprised about 8, 6, and 35% of total soluble protein, respectively, at near optimal growth condition. In contrast to significant increase in the proportion of soluble protein allocated to PEPC and PPD seen under certain conditions, the proportion allocated to RuBisCO decreased reciprocally with an increased biomass yield by N supply.These results indicated that the levels of PEPC and PPD parallel to maize biomass more tightly than that of RuBisCO at least under near optimal growth condition. PMID:16663684

  17. Wheat cytosolic acetyl-CoA carboxylase complements an ACC1 null mutation in yeast

    OpenAIRE

    Joachimiak, M.; Tevzadze, G.; Podkowinski, J; Haselkorn, R.; Gornicki, P.

    1997-01-01

    Spores harboring an ACC1 deletion derived from a diploid Saccharomyces cerevisiae strain, in which one copy of the entire ACC1 gene is replaced with a LEU2 cassette, fail to grow. A chimeric gene consisting of the yeast GAL10 promoter, yeast ACC1 leader, wheat cytosolic acetyl-CoA carboxylase (ACCase) cDNA, and yeast ACC1 3′ tail was used to complement a yeast ACC1 mutation. The complementation demonstrates that active wheat ACCase can be produced in yeast. At low concentrations of galactose,...

  18. Isolation of ribulose-1,5-bisphosphate carboxylase/oxygenase from leaves.

    Science.gov (United States)

    Carmo-Silva, A Elizabete; Barta, Csengele; Salvucci, Michael E

    2011-01-01

    Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is a multifunctional enzyme that catalyzes the fixation of CO2 and O2 in photosynthesis and photorespiration, respectively. As the rate-limiting step in photosynthesis, improving the catalytic properties of Rubisco has long been viewed as a viable strategy for increasing plant productivity. Advances in biotechnology have made this goal more attainable by making it possible to modify Rubisco in planta. To properly evaluate the properties of Rubisco, it is necessary to isolate the enzyme in pure form. This chapter describes procedures for rapid and efficient purification of Rubisco from leaves of several species. PMID:20960141

  19. Attempts to apply affinity labeling techniques to ribulosebisphosphate carboxylase/oxygenase. [Comparison of spinach leaf and Rhodospirillum rubrum

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, F. C.; Norton, I. L.; Stringer, C. D.; Schloss, J. V.

    1978-01-01

    Studies on carboxylases/oxygenases from different species may be necessary to confirm that a residue implicated as essential is indeed an active-site component. To provide an especially stringent test case for the identification of species invariant structural features the enzymes from two phylogenetically distant species, spinach and Rhodospirillum rubrum, were compared. To date, the reactions of Br-butanone-P/sub 2/ and BrAcNHEtOP with the spinach enayme have been rather thoroughly characterized; only preliminary experiments have been completed with the R. rubrum enzyme. Both enzymes were isolated and assayed for carboxylase activity (spectrophotometrically or /sup 14/CO/sub 2/-fixation) and for oxygenase activity.

  20. Active site histidine in spinach ribulosebisphosphate carboxylase/oxygenase modified by diethyl pyrocarbonate

    International Nuclear Information System (INIS)

    [3H] Diethyl pyrocarbonate was synthesized from [3H] ethanol prepared by the reduction of acetaldehyde by NaB3H4. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) from spinach was inactivated with this reagent at pH 7.0 the presence of 20 mM Mg2+, and tryptic peptides that contained modified histidine residues were isolated by reverse-phase high-performance liquid chromatography. Labeling of the enzyme was conducted in the presence and absence of the competitive inhibitor sedoheptulose 1,7-bisphosphate. The amount of one peptide that was heavily labeled in the absence of this compound was reduced 10-fold in its presence. The labeled residue was histidine-298. This result, in combination with earlier experiments, suggests that His-298 in spinach RuBisCO is located in the active site domain and is essential to enzyme activity. This region of the primary structure is strongly conserved in seven other ribulosebisphosphate carboxylases from divergent sources

  1. Dark/light modulation of ribulose bisphosphate carboxylase activity in plants from different photosynthetic categories

    Energy Technology Data Exchange (ETDEWEB)

    Vu, J.C.V.; Allen, L.H. Jr.; Bowes, G.

    1984-11-01

    Ribulose bisphosphate carboxylase/oxygenase (RuBPCase) from several plants had substantially greater activity in extracts from light-exposed leaves than dark leaves, even when the extracts were incubated in vitro with saturating HCO/sub 3//sup -/ and Mg/sup 2 +/ concentrations. This occurred in Glycine max, Lycopersicon esculentum, Nicotiana tabacum, Panicum bisulcatum, and P. hylaeicum (C/sub 3/); P. maximum (C/sub 4/ phosphoenolpyruvate carboxykinase); P. milioides (C/sub 3//C/sub 4/); and Bromelia pinguin and Ananas comosus (Crassulacean acid metabolism). Little or no difference between light and dark leaf extracts of RuBPCase was observed in Triticum aestivum (C/sub 3/); P. miliaceum (C/sub 4/ NAD malic enzyme); Zea mays and Sorghum bicolor (C/sub 4/ NADP malic enzyme); Moricandia arvensis (C/sub 3//C/sub 4/); and Hydrilla verticillata (submersed aquatic macrophyte). It is concluded that, in many plants, especially Crassulacean acid metabolism and C/sub 3/ species, a large fraction of ribulose-1,5-bisphosphate carboxylase/oxygenase in the dark is in an inactivatable state that cannot respond to CO/sub 2/ and Mg/sup 2 +/ activation, but which can be converted to an activatable state upon exposure of the leaf to light. 16 references, 2 tables.

  2. Dark/Light Modulation of Ribulose Bisphosphate Carboxylase Activity in Plants from Different Photosynthetic Categories 1

    Science.gov (United States)

    Vu, J. Cu V.; Allen, Leon H.; Bowes, George

    1984-01-01

    Ribulose bisphosphate carboxylase/oxygenase (RuBPCase) from several plants had substantially greater activity in extracts from lightexposed leaves than dark leaves, even when the extracts were incubated in vitro with saturating HCO3− and Mg2+ concentrations. This occurred in Glycine max, Lycopersicon esculentum, Nicotiana tabacum, Panicum bisulcatum, and P. hylaeicum (C3); P. maximum (C4 phosphoenolpyruvate carboxykinase); P. milioides (C3/C4); and Bromelia pinguin and Ananas comosus (Crassulacean acid metabolism). Little or no difference between light and dark leaf extracts of RuBPCase was observed in Triticum aestivum (C3); P. miliaceum (C4 NAD malic enzyme); Zea mays and Sorghum bicolor (C4 NADP malic enzyme); Moricandia arvensis (C3/C4); and Hydrilla verticillata (submersed aquatic macrophyte). It is concluded that, in many plants, especially Crassulacean acid metabolism and C3 species, a large fraction of ribulose-1,5-bisphosphate carboxylase/oxygenase in the dark is in an inactivatable state that cannot respond to CO2 and Mg2+ activation, but which can be converted to an activatable state upon exposure of the leaf to light. PMID:16663937

  3. Dark/Light modulation of ribulose bisphosphate carboxylase activity in plants from different photosynthetic categories.

    Science.gov (United States)

    Vu, J C; Allen, L H; Bowes, G

    1984-11-01

    Ribulose bisphosphate carboxylase/oxygenase (RuBPCase) from several plants had substantially greater activity in extracts from lightexposed leaves than dark leaves, even when the extracts were incubated in vitro with saturating HCO(3) (-) and Mg(2+) concentrations. This occurred in Glycine max, Lycopersicon esculentum, Nicotiana tabacum, Panicum bisulcatum, and P. hylaeicum (C(3)); P. maximum (C(4) phosphoenolpyruvate carboxykinase); P. milioides (C(3)/C(4)); and Bromelia pinguin and Ananas comosus (Crassulacean acid metabolism). Little or no difference between light and dark leaf extracts of RuBPCase was observed in Triticum aestivum (C(3)); P. miliaceum (C(4) NAD malic enzyme); Zea mays and Sorghum bicolor (C(4) NADP malic enzyme); Moricandia arvensis (C(3)/C(4)); and Hydrilla verticillata (submersed aquatic macrophyte). It is concluded that, in many plants, especially Crassulacean acid metabolism and C(3) species, a large fraction of ribulose-1,5-bisphosphate carboxylase/oxygenase in the dark is in an inactivatable state that cannot respond to CO(2) and Mg(2+) activation, but which can be converted to an activatable state upon exposure of the leaf to light. PMID:16663937

  4. A Symmetrical Tetramer for S. aureus Pyruvate Carboxylase in Complex with Coenzyme A

    Energy Technology Data Exchange (ETDEWEB)

    Yu, L.; Xiang, S; Lasso, G; Gil, D; Valle, M; Tong, L

    2009-01-01

    Pyruvate carboxylase (PC) is a conserved metabolic enzyme with important cellular functions. We report crystallographic and cryo-electron microscopy (EM) studies of Staphylococcus aureus PC (SaPC) in complex with acetyl-CoA, an allosteric activator, and mutagenesis, biochemical, and structural studies of the biotin binding site of its carboxyltransferase (CT) domain. The disease-causing A610T mutation abolishes catalytic activity by blocking biotin binding to the CT active site, and Thr908 might play a catalytic role in the CT reaction. The crystal structure of SaPC in complex with CoA reveals a symmetrical tetramer, with one CoA molecule bound to each monomer, and cryo-EM studies confirm the symmetrical nature of the tetramer. These observations are in sharp contrast to the highly asymmetrical tetramer of Rhizobium etli PC in complex with ethyl-CoA. Our structural information suggests that acetyl-CoA promotes a conformation for the dimer of the biotin carboxylase domain of PC that might be catalytically more competent.

  5. Immunochemical localization of ribulose-1,5-bisphosphate carboxylase in the symbiont-containing gills of Solemya velum (Bivalvia : Mollusca)

    NARCIS (Netherlands)

    Cavanaugh, Colleen M.; Abbott, Marilyn S.; Veenhuis, Marten

    1988-01-01

    The distribution of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase (RbuP2Case; EC 4.1.1.39) was examined by using two immunological methods in tissues of Solemya velum, an Atlantic coast bivalve containing putative chemoautotrophic symbionts. Antibodies elicited by the purified large

  6. Resolving the Activation Site of PositiveRegulators in Plant PhosphoenolpyruvateCarboxylase

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Dear Editor, Phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) islocated at an important branch point in the carbohydratemetabolism of plants. The enzyme is a homotetramer andcatalyzes the addition of bicarbonate to phosphoenolpyru-vate (PEP) to form oxaloacetate and phosphate. PEPC isregulated by metabolites and phosphorylation. AIIostericfeedback inhibition is mainly regulated by L-malate andL-aspartate which bind to a site separated from the activecenter (Kai et al., 1999; Paulus et al., 2013). Structure analy-sis of PEPC from Escherichia coli (Kai et al., 1999; Matsumuraet al., 2002), Zea rnays (Matsumura et al., 2002), Flaveria trin-ervia, and F. pringlei (Paulus et al., 2013) revealed that thesubstrate PEP and the feedback inhibitors bind to separatesites within each monomer.

  7. Is L-Carnitine Supplementation Beneficial in 3-Methylcrotonyl-CoA Carboxylase Deficiency?

    DEFF Research Database (Denmark)

    Thomsen, Jákup Andreas; Lund, Allan Meldgaard; Olesen, Jess Have; Mohr, Magni; Rasmussen, Jan

    2015-01-01

    Background: 3-Methylcrotonyl-CoA carboxylase deficiency (3-MCCd) is an autosomal recessive disorder in the catabolism of leucine. In the present study, we investigated the current and prior medical condition of patients with 3-MCCd in the Faroe Islands and their carnitine levels in blood, urine and...... muscle tissue with and without L-carnitine supplementation to evaluate the current treatment strategy of not recommending L-carnitine supplementation to Faroese 3-MCCd patients. Methods: Blood and urine samples and muscle biopsies were collected from patients at inclusion and at 3 months. Eight patients...... received L-carnitine supplementation when recruited; five did not. Included patients who received supplementation were asked to stop L-carnitine, the others were asked to initiate L-carnitine supplementation during the study. Symptoms were determined by review of hospital medical records and questionnaires...

  8. Acetyl CoA Carboxylase 2 Is Dispensable for CD8+ T Cell Responses.

    Directory of Open Access Journals (Sweden)

    Jang Eun Lee

    Full Text Available Differentiation of T cells is closely associated with dynamic changes in nutrient and energy metabolism. However, the extent to which specific metabolic pathways and molecular components are determinative of CD8+ T cell fate remains unclear. It has been previously established in various tissues that acetyl CoA carboxylase 2 (ACC2 regulates fatty acid oxidation (FAO by inhibiting carnitine palmitoyltransferase 1 (CPT1, a rate-limiting enzyme of FAO in mitochondria. Here, we explore the cell-intrinsic role of ACC2 in T cell immunity in response to infections. We report here that ACC2 deficiency results in a marginal increase of cellular FAO in CD8+ T cells, but does not appear to influence antigen-specific effector and memory CD8+ T cell responses during infection with listeria or lymphocytic choriomeningitis virus. These results suggest that ACC2 is dispensable for CD8+ T cell responses.

  9. Novel Mutations in the PC Gene in Patients with Type B Pyruvate Carboxylase Deficiency

    DEFF Research Database (Denmark)

    Ostergaard, Elsebet; Duno, Morten; Møller, Lisbeth Birk;

    2013-01-01

    We have investigated seven patients with the type B form of pyruvate carboxylase (PC) deficiency. Mutation analysis revealed eight mutations, all novel. In a patient with exon skipping on cDNA analysis, we identified a homozygous mutation located in a potential branch point sequence, the first...... possible branch point mutation in PC. Two patients were homozygous for missense mutations (with normal protein amounts on western blot analysis), and two patients were homozygous for nonsense mutations. In addition, a duplication of one base pair was found in a patient who also harboured a splice site...... mutation. Another splice site mutation led to the activation of a cryptic splice site, shown by cDNA analysis.All patients reported until now with at least one missense mutation have had the milder type A form of PC deficiency. We thus report for the first time two patients with homozygous missense...

  10. Structural and Biochemical Studies on the Regulation of Biotin Carboxylase by Substrate Inhibition and Dimerization

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Chi-Yuan; Tong, Liang (Columbia)

    2012-06-19

    Biotin carboxylase (BC) activity is shared among biotin-dependent carboxylases and catalyzes the Mg-ATP-dependent carboxylation of biotin using bicarbonate as the CO{sub 2} donor. BC has been studied extensively over the years by structural, kinetic, and mutagenesis analyses. Here we report three new crystal structures of Escherichia coli BC at up to 1.9 {angstrom} resolution, complexed with different ligands. Two structures are wild-type BC in complex with two ADP molecules and two Ca{sup 2+} ions or two ADP molecules and one Mg{sup 2+} ion. One ADP molecule is in the position normally taken by the ATP substrate, whereas the other ADP molecule occupies the binding sites of bicarbonate and biotin. One Ca{sup 2+} ion and the Mg{sup 2+} ion are associated with the ADP molecule in the active site, and the other Ca{sup 2+} ion is coordinated by Glu-87, Glu-288, and Asn-290. Our kinetic studies confirm that ATP shows substrate inhibition and that this inhibition is competitive against bicarbonate. The third structure is on the R16E mutant in complex with bicarbonate and Mg-ADP. Arg-16 is located near the dimer interface. The R16E mutant has only a 2-fold loss in catalytic activity compared with the wild-type enzyme. Analytical ultracentrifugation experiments showed that the mutation significantly destabilized the dimer, although the presence of substrates can induce dimer formation. The binding modes of bicarbonate and Mg-ADP are essentially the same as those to the wild-type enzyme. However, the mutation greatly disrupted the dimer interface and caused a large re-organization of the dimer. The structures of these new complexes have implications for the catalysis by BC.

  11. Inhibition of E. coli P-enolpyruvate carboxylase by P-enol-3-bromopyruvate

    International Nuclear Information System (INIS)

    The generality of the mechanism based inhibition of P-enolpyruvate carboxylases (PEPCase) by P-enol-3-bromopyruvate (BrPEP) was tested by measuring its effects on the allosterically regulated enzyme from E. coli. In the presence of 1mM Mn2+, BrPEP appears to be a competitive inhibitor (K/sub i/ = 0.0087mM) of PEPCase. Incubation of 0.005mM PEPCase with 0.5mM (or 1.0mM)BrPEP along with H14CO3- and Mn2+, yielded, upon reduction with NaBH4, a protein containing radioactivity in an amount approximately proportional to that expected from the loss of catalytic activity. At both a 25- and a 50-fold excess (0.5mM and 1.0mM, respectively) of BrPEP to PEPCase subunits, first order loss of activity occurred with k values of 5.24 x 10-3 min-1 and 1.03 x 10-2 min-1, respectively. At the lower concentration of BrPEP the inactivation process appeared to be reversible after 40 min with no further inhibition occurring even up to two hours of incubation. At the higher concentration of BrPEP, the rate of inhibition slowed dramatically after 50 min and appeared insignificant over the next hour. These data suggest that BrPEP irreversibly inactivates the E. coli PEP carboxylase, but that there may be considerable dissociation of the product, Br-oxaloacetate, before irreversible binding occurs, and that the reduced rate of inactivation may be due to depletion of BrPEP

  12. Molecular cloning and characterization of the cDNA coding for the biotin-containing subunit of 3-methylcrotonoyl-CoA carboxylase: identification of the biotin carboxylase and biotin-carrier domains.

    OpenAIRE

    Song, J.; Wurtele, E S; Nikolau, B J

    1994-01-01

    Soybean genomic clones were isolated based on hybridization to probes that code for the conserved biotinylation domain of biotin-containing enzymes. The corresponding cDNA was isolated and expressed in Escherichia coli through fusion to the bacterial trpE gene. The resulting chimeric protein was biotinylated in E. coli. Antibodies raised against the chimeric protein reacted specifically with an 85-kDa biotin-containing polypeptide from soybean and inhibited 3-methylcrotonoyl-CoA carboxylase (...

  13. Electron spin resonance studies of ribulosebisphosphate carboxylase: identification of activator cation ligands.

    Science.gov (United States)

    Miziorko, H M; Sealy, R C

    1984-01-31

    Ribulosebisphosphate carboxylase (RuBP carboxylase)forms a stable model complex containing stoichiometric amounts of enzyme sites, activator C0(2), divalent activator cation, and the transition-state analogue carboxyarabinitol bisphosphate (CABP). Incorporation of Mn(2+) in the model complex permits investigation of the environment of the activator cation by electron spin resonance (ESR)techniques. Measurements at 9 GHz on the Mn(2+)-containing complex prepared by using dimeric Rhodospirillum rubrum enzyme produce a spectrum which indicates that the cation is bound in an anisotropic environment. Measurements at 9 GHz on the spinach enzyme model complex produce a spectrum in which several of the fine structure transitions are obvious. In contrast, the spectrum produced from Mn(2+) bound to R. rubrum enzyme exhibits an intense powder pattern for the central fine structure transition; the other four fine structure transitions produce powder patterns that are in homogeneously broadened and therefore are not as apparent.Low-temperature measurements at high field (35 GHz) result in substantially simplified spectra. The spectrum of Mn(2+) bound to the R. rubrum enzyme shows less fine structure than the spectrum of Mn(2+) bound in the octameric spinach enzyme complex, where substantial hyperfine splitting is resolved in three of the five fine structure transitions. Measurements at 35 GHz on Mn (2+) bound in the dimeric R. rubrum enzyme complex produce spectra in which only the central fine structure transition produces a prominent signal. However, these samples are characterized by several narrow spectral features which permit investigation of the identity of Mn(2+)ligands by 170 perturbation techniques. Preparation of the R. rubrum RuBP carboxylase model complex in (17)O-enriched water results in a sample which exhibits an obviously broadened 35-GHz Mn(2+) spectrum in comparison to unenriched samples. Removal of H(2)(17)O by gel filtration abolished the spectral

  14. Propeptide and glutamate-containing substrates bound to the vitamin K-dependent carboxylase convert its vitamin K epoxidase function from an inactive to an active state

    OpenAIRE

    Sugiura, Isamu; Furie, Bruce; Walsh, Christopher T.; Furie, Barbara C.

    1997-01-01

    The vitamin K-dependent γ-glutamyl carboxylase catalyzes the posttranslational conversion of glutamic acid to γ-carboxyglutamic acid in precursor proteins containing the γ-carboxylation recognition site (γ-CRS). During this reaction, glutamic acid is converted to γ-carboxyglutamic acid while vitamin KH2 is converted to vitamin K 2,3-epoxide. Recombinant bovine carboxylase was purified free of γ-CRS-containing propeptide and endogenous substrate in a single-step immunoaffinity procedure. We sh...

  15. /sup 13/C nuclear magnetic resonance study of the CO/sub 2/ activation of ribulosebisphosphate carboxylase from Rhodospirillum rubrum

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, M.H. (Univ. of Wisconsin, Madison); Joworski, R.J.; Hartman, F.C.

    1979-02-01

    Ribulosebisphosphate carboxylase (3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39) from Rhodospirillum rubrum is activated by CO/sub 2/ and Mg/sup 2 +/. /sup 13/C NMR spectra were determined for the unactivated enzyme and for enzyme that had been activated by /sup 13/CO/sub 2/ and Mg/sup 2 +/. In addition to the expected resonance for H/sup 13/CO/sub 3//sup -//CO/sub 3//sup 2 -/ at 161.8 ppM downfield from tetramethylsilane, the spectrum of the activated enzyme shows a broad resonance at 164.9 ppM. Analogy with previous NMR studies of /sup 13/CO/sub 2/ binding to hemoglobin suggests that the CO/sub 2/ activation of ribulosebisphosphate carboxylase involves formation of a carbamate between an enzyme amino group and CO/sub 2/.

  16. Insights into the carboxyltransferase reaction of pyruvate carboxylase from the structures of bound product and intermediate analogues

    OpenAIRE

    Lietzan, Adam D.; St. Maurice, Martin

    2013-01-01

    Pyruvate carboxylase (PC) is a biotin-dependent enzyme that catalyzes the MgATP- and bicarbonate-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in central metabolism. The carboxyltransferase (CT) domain of PC catalyzes the transfer of a carboxyl group from carboxybiotin to the accepting substrate, pyruvate. It has been hypothesized that the reactive enolpyruvate intermediate is stabilized through a bidentate interaction with the metal ion in the CT doma...

  17. Biotin Uptake into Human Peripheral Blood Mononuclear Cells Increases Early in the Cell Cycle, Increasing Carboxylase Activities1,2

    OpenAIRE

    Stanley, J. Steven; Mock, Donald M.; Griffin, Jacob B.; Zempleni, Janos

    2002-01-01

    Cells respond to proliferation with increased accumulation of biotin, suggesting that proliferation enhances biotin demand. Here we determined whether peripheral blood mononuclear cells (PBMC) increase biotin uptake at specific phases of the cell cycle, and whether biotin is utilized to increase biotinylation of carboxylases. Biotin uptake was quantified in human PBMC that were arrested chemically at specific phases of the cell cycle, i.e., biotin uptake increased in the G1 phase of the cycle...

  18. Soybean ribulose bisphosphate carboxylase small subunit: Mechanisms and determinants of RNA turnover. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, R.B. [Georgia Univ., Athens, GA (United States). Dept. of Genetics

    1993-12-31

    An in vitro degradation system has been developed from petunia and soybean polysomes in order to investigate the mechanisms and determinants controlling RNA turnover in higher plants. This system faithfully degrades soybean ribulose-1,5-bisphosphate carboxylase small subunit (rbcS) mRNA into the same products observed in total RNA preparations. In previous years it was shown that the most stable products represent a nested constellation of fragments, which are shortened from their 3{prime} ends, and have intact 5{prime} ends. Exogenous rbcS RNA tagged with novel 5{prime} sequence 15 or 56 bp long were synthesized in vitro as Sp6 and T7 runoff transcripts, respectively. When added to the system they were degraded faithfully into constellation of products which were 15 or 56 bp longer than the endogenous products, respectively. Detailed kinetics on the appearance of these exogenous products confirmed degradation proceeds in an overall 3{prime} to 5{prime} direction but suggested that there are multiple pathways through which the RNA may be degraded. To further demonstrate a precursor product relationships, in vitro synthesized transcripts truncated at their 3{prime} ends were shown to degrade into the expected smaller fragments previously mapped in the 5{prime} portion of the rbcS RNA.

  19. 3-methylcrotonyl-CoA carboxylase deficiency: Clinical, biochemical, enzymatic and molecular studies in 88 individuals

    Directory of Open Access Journals (Sweden)

    Grünert Sarah C

    2012-05-01

    Full Text Available Abstract Background Isolated 3-methylcrotonyl-CoA carboxylase (MCC deficiency is an autosomal recessive disorder of leucine metabolism caused by mutations in MCCC1 or MCCC2 encoding the α and β subunit of MCC, respectively. The phenotype is highly variable ranging from acute neonatal onset with fatal outcome to asymptomatic adults. Methods We report clinical, biochemical, enzymatic and mutation data of 88 MCC deficient individuals, 53 identified by newborn screening, 26 diagnosed due to clinical symptoms or positive family history and 9 mothers, identified following the positive newborn screening result of their baby. Results Fifty-seven percent of patients were asymptomatic while 43% showed clinical symptoms, many of which were probably not related to MCC deficiency but due to ascertainment bias. However, 12 patients (5 of 53 identified by newborn screening presented with acute metabolic decompensations. We identified 15 novel MCCC1 and 16 novel MCCC2 mutant alleles. Additionally, we report expression studies on 3 MCCC1 and 8 MCCC2 mutations and show an overview of all 132 MCCC1 and MCCC2 variants known to date. Conclusions Our data confirm that MCC deficiency, despite low penetrance, may lead to a severe clinical phenotype resembling classical organic acidurias. However, neither the genotype nor the biochemical phenotype is helpful in predicting the clinical course.

  20. Ribulose-1,5-bisphosphate Carboxylase/Oxygenase content, assimilatory charge, and mesophyll conductance in leaves

    Science.gov (United States)

    Eichelmann; Laisk

    1999-01-01

    The content of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) (Et; EC 4.1.1.39) measured in different-aged leaves of sunflower (Helianthus annuus) and other plants grown under different light intensities, varied from 2 to 75 &mgr;mol active sites m-2. Mesophyll conductance (&mgr;) was measured under 1.5% O2, as well as postillumination CO2 uptake (assimilatory charge, a gas-exchange measure of the ribulose-1,5-bisphosphate pool). The dependence of &mgr; on Et saturated at Et = 30 &mgr;mol active sites m-2 and &mgr; = 11 mm s-1 in high-light-grown leaves. In low-light-grown leaves the dependence tended toward saturation at similar Et but reached a &mgr; of only 6 to 8 mm s-1. &mgr; was proportional to the assimilatory charge, with the proportionality constant (specific carboxylation efficiency) between 0.04 and 0.075 &mgr;M-1 s-1. Our data show that the saturation of the relationship between Et and &mgr; is caused by three limiting components: (a) the physical diffusion resistance (a minor limitation), (b) less than full activation of Rubisco (related to Rubisco activase and the slower diffusibility of Rubisco at high protein concentrations in the stroma), and (c) chloroplast metabolites, especially 3-phosphoglyceric acid and free inorganic phosphate, which control the reaction kinetics of ribulose-1,5-bisphosphate carboxylation by competitive binding to active sites. PMID:9880359

  1. Pyruvate carboxylase is critical for non-small-cell lung cancer proliferation.

    Science.gov (United States)

    Sellers, Katherine; Fox, Matthew P; Bousamra, Michael; Slone, Stephen P; Higashi, Richard M; Miller, Donald M; Wang, Yali; Yan, Jun; Yuneva, Mariia O; Deshpande, Rahul; Lane, Andrew N; Fan, Teresa W-M

    2015-02-01

    Anabolic biosynthesis requires precursors supplied by the Krebs cycle, which in turn requires anaplerosis to replenish precursor intermediates. The major anaplerotic sources are pyruvate and glutamine, which require the activity of pyruvate carboxylase (PC) and glutaminase 1 (GLS1), respectively. Due to their rapid proliferation, cancer cells have increased anabolic and energy demands; however, different cancer cell types exhibit differential requirements for PC- and GLS-mediated pathways for anaplerosis and cell proliferation. Here, we infused patients with early-stage non-small-cell lung cancer (NSCLC) with uniformly 13C-labeled glucose before tissue resection and determined that the cancerous tissues in these patients had enhanced PC activity. Freshly resected paired lung tissue slices cultured in 13C6-glucose or 13C5,15N2-glutamine tracers confirmed selective activation of PC over GLS in NSCLC. Compared with noncancerous tissues, PC expression was greatly enhanced in cancerous tissues, whereas GLS1 expression showed no trend. Moreover, immunohistochemical analysis of paired lung tissues showed PC overexpression in cancer cells rather than in stromal cells of tumor tissues. PC knockdown induced multinucleation, decreased cell proliferation and colony formation in human NSCLC cells, and reduced tumor growth in a mouse xenograft model. Growth inhibition was accompanied by perturbed Krebs cycle activity, inhibition of lipid and nucleotide biosynthesis, and altered glutathione homeostasis. These findings indicate that PC-mediated anaplerosis in early-stage NSCLC is required for tumor survival and proliferation. PMID:25607840

  2. Relationship between NH4+ assimilation rate and in vivo phosphoenolpyruvate carboxylase activity

    International Nuclear Information System (INIS)

    The rate of NH4+ assimilation by N-limited Selenastrum minutum (Naeg.) Collins cells in the dark was set as an independent variable and the relationship between NH4+ assimilation rate and in vivo activity of phosphoenolpyruvate carboxylase (PEPC) was determined. In vivo activity of PEPC was measured by following the incorporation of H14CO3- into acid stable products. A linear relationship of 0.3 moles C fixed via PEPC per mole N assimilated was observed. This value agrees extremely well with the PEPC requirement for the synthesis of the amino acids found in total cellular protein. Determinations of metabolite levels in vivo at different rates of N assimilation indicated that the known metabolite effectors of S. minutum PEPC in vitro (KA Schuller, WC Plaxton, DH Turpin, [1990] Plant Physiol 93: 1303-1311) are important regulators of this enzyme during N assimilation. As PEPC activity increased in response to increasing rates of N assimilation, there was a corresponding decline in the level of PEPC inhibitors (2-oxoglutarate, malate), an increase in the level of PEPC activators (glutamine, dihydroxyacetone phosphate), and an increase in the Gln/Glu ratio. Treatment of N-limited cells with azaserine caused an increase in the Gln/Glu ratio resulting in increased PEPC activity in the absence of N assimilation. We suggest glutamate and glutamine play a key role in regulating the anaplerotic function of PEPC in this C3 organism

  3. Improving polyketide and fatty acid synthesis by engineering of the yeast acetyl-CoA carboxylase.

    Science.gov (United States)

    Choi, Jin Wook; Da Silva, Nancy A

    2014-10-10

    Polyketides and fatty acids are important in the production of pharmaceuticals, industrial chemicals, and biofuels. The synthesis of the malonyl-CoA building block, catalyzed by acetyl-CoA carboxylase (Acc1), is considered a limiting step to achieving high titers of polyketides and fatty acids in Saccharomyces cerevisiae. Acc1 is deactivated by AMP-activated serine/threonine protein kinase (Snf1) when glucose is depleted. To prevent this deactivation, the enzyme was aligned with the Rattus norvegicus (rat) Acc1 to identify a critical amino acid (Ser-1157) for phosphorylation and deactivation. Introduction of a S1157A mutation into Acc1 resulted in 9-fold higher specific activity following glucose depletion. The enzyme was tested in yeast engineered to produce the polyketide 6-methylsalisylic acid (6-MSA). Both 6-MSA and native fatty acid levels increased by 3-fold. Utilization of this modified Acc1 enzyme will also be beneficial for other products built from malonyl-CoA. PMID:25078432

  4. Cloning and characterization of cotton heteromeric acetyl-CoA carboxylase genes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Heteromeric acetyl-coanzyme A(CoA)carboxylese(ACCase)catalyzes the formation of malonyl-CoA from acetyl-CoA.It plays an essential role in fatty acid synthesis in prokaryotes and most of plants.The heteromeric ACCase is composed of four subunits:biotin carboxylase (BC),biotin carboxyl carrier protein (BCCP),and α-and β-subunits of carboxyltransferese(α-andβ-CT).In this study,we cloned five novel genes encoding the subunits of heteromeric ACCese(one BC,BCCP and β-CT,and two α-CTs) from cotton (Gossypium hirsutum cv.zhongmian 35)by RACE-PCR.The deduced amino acid sequence of these cDNAs shares high similarity with other reported heteromeric ACCese subunits.The phylogenetic analysis indicated that the different subunits of heteromeric ACCase were grouped in a similar pattern.Southern blot analysis revealed the milti-copy patterns of these heteromeric ACCase genes in cotton genome.Semi-quantitative RT-PCR demonstrated that heteromeric ACCese genes were constitutively expressed in all of the cotton tissues,but the transcripts accumulated at a relatively low level in roots.To our knowledge,this is the first report about characterization of the heteromeric ACCase genes in cotton.

  5. Deregulation of feedback inhibition of phosphoenolpyruvate carboxylase for improved lysine production in Corynebacterium glutamicum.

    Science.gov (United States)

    Chen, Zhen; Bommareddy, Rajesh Reddy; Frank, Doinita; Rappert, Sugima; Zeng, An-Ping

    2014-02-01

    Allosteric regulation of phosphoenolpyruvate carboxylase (PEPC) controls the metabolic flux distribution of anaplerotic pathways. In this study, the feedback inhibition of Corynebacterium glutamicum PEPC was rationally deregulated, and its effect on metabolic flux redistribution was evaluated. Based on rational protein design, six PEPC mutants were designed, and all of them showed significantly reduced sensitivity toward aspartate and malate inhibition. Introducing one of the point mutations (N917G) into the ppc gene, encoding PEPC of the lysine-producing strain C. glutamicum LC298, resulted in ∼37% improved lysine production. In vitro enzyme assays and (13)C-based metabolic flux analysis showed ca. 20 and 30% increases in the PEPC activity and corresponding flux, respectively, in the mutant strain. Higher demand for NADPH in the mutant strain increased the flux toward pentose phosphate pathway, which increased the supply of NADPH for enhanced lysine production. The present study highlights the importance of allosteric regulation on the flux control of central metabolism. The strategy described here can also be implemented to improve other oxaloacetate-derived products. PMID:24334667

  6. Ribulose Bisphosphate Carboxylase Activity in Anther-Derived Plants of Saintpaulia ionantha Wendl. Shag.

    Science.gov (United States)

    Bhaskaran, S; Smith, R H; Finer, J J

    1983-11-01

    Plants obtained from anther culture of the African violet, Saintpaulia ionantha Wendl. ;Shag' and vegetatively cloned copies of the parent anther donor plant were examined for their ploidy and ribulose-1,5-biphosphate carboxylase (RuBPcase) activity. The cloned parent plants were all diploid and did not vary much in their nuclear DNA, chlorophyll, and RuBPcase activity. Some of the anther-derived plants were similar to the parent plants while others were not. Different levels of ploidy were observed among the androgenetic plants. RuBPcase activities higher than that of the parent plants were found in some anther-derived plants. However, there was no direct correlation between ploidy and RuBPcase activity. Expression of nuclear genes from a single parent in the anther-derived plants and it's diploidization or plastid changes during early stages of microsporogenesis or androgenesis are suggested as possible reasons for the variations observed among them. This could be a useful technique to obtain physiological variants which could be agronomically desirable. PMID:16663273

  7. Pyruvate carboxylase as a sensitive protein biomarker for exogenous steroid chemicals

    International Nuclear Information System (INIS)

    Assessing protein responses to endocrine disrupting chemicals is critical for understanding the mechanisms of chemical action and for the assessment of hazards. In this study, the response of the liver proteome of male rare minnows (Gobiocypris rarus) treated with 17β-estradiol (E2) and females treated with 17α-methyltestosterone (MT) were analyzed. A total of 23 and 24 proteins were identified with differential expression in response to E2 and MT, respectively. Pyruvate carboxylase (PC) was the only common differentially expressed protein in both males and females after E2- and MT-treatments. The mRNA as well as the protein levels of PC were significantly down-regulated compared with that of the controls (p < 0.05). Our results suggest that endocrine disruptors interfere with genes and proteins of the TCA cycle and PC may be a sensitive biomarker of exposure to exogenous steroid chemicals in the liver of fish. - Highlights: • The hepatic proteomes of rare minnow (Gobiocypris rarus) exposed to E2 and MT were analyzed. • Differentially expressed proteins (23 and 24 respectively) were identified following E2 and MT exposure. • Four differentially expressed proteins associated with chemical stimulus were characterized. • PC was identified as a responsive biomarker for both estrogens and androgens. - Our results suggest PC may be a sensitive biomarker of exposure to exogenous steroid chemicals in the liver of fish

  8. Functional metagenomic selection of ribulose 1, 5-bisphosphate carboxylase/oxygenase from uncultivated bacteria.

    Science.gov (United States)

    Varaljay, Vanessa A; Satagopan, Sriram; North, Justin A; Witte, Brian; Dourado, Manuella N; Anantharaman, Karthik; Arbing, Mark A; McCann, Shelley Hoeft; Oremland, Ronald S; Banfield, Jillian F; Wrighton, Kelly C; Tabita, F Robert

    2016-04-01

    Ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) is a critical yet severely inefficient enzyme that catalyses the fixation of virtually all of the carbon found on Earth. Here, we report a functional metagenomic selection that recovers physiologically active RubisCO molecules directly from uncultivated and largely unknown members of natural microbial communities. Selection is based on CO2 -dependent growth in a host strain capable of expressing environmental deoxyribonucleic acid (DNA), precluding the need for pure cultures or screening of recombinant clones for enzymatic activity. Seventeen functional RubisCO-encoded sequences were selected using DNA extracted from soil and river autotrophic enrichments, a photosynthetic biofilm and a subsurface groundwater aquifer. Notably, three related form II RubisCOs were recovered which share high sequence similarity with metagenomic scaffolds from uncultivated members of the Gallionellaceae family. One of the Gallionellaceae RubisCOs was purified and shown to possess CO2 /O2 specificity typical of form II enzymes. X-ray crystallography determined that this enzyme is a hexamer, only the second form II multimer ever solved and the first RubisCO structure obtained from an uncultivated bacterium. Functional metagenomic selection leverages natural biological diversity and billions of years of evolution inherent in environmental communities, providing a new window into the discovery of CO2 -fixing enzymes not previously characterized. PMID:26617072

  9. Multiple inter-kingdom horizontal gene transfers in the evolution of the phosphoenolpyruvate carboxylase gene family.

    Science.gov (United States)

    Peng, Yingmei; Cai, Jing; Wang, Wen; Su, Bing

    2012-01-01

    Pepcase is a gene encoding phosphoenolpyruvate carboxylase that exists in bacteria, archaea and plants,playing an important role in plant metabolism and development. Most plants have two or more pepcase genes belonging to two gene sub-families, while only one gene exists in other organisms. Previous research categorized one plant pepcase gene as plant-type pepcase (PTPC) while the other as bacteria-type pepcase (BTPC) because of its similarity with the pepcase gene found in bacteria. Phylogenetic reconstruction showed that PTPC is the ancestral lineage of plant pepcase, and that all bacteria, protistpepcase and BTPC in plants are derived from a lineage of pepcase closely related with PTPC in algae. However, their phylogeny contradicts the species tree and traditional chronology of organism evolution. Because the diversification of bacteria occurred much earlier than the origin of plants, presumably all bacterialpepcase derived from the ancestral PTPC of algal plants after divergingfrom the ancestor of vascular plant PTPC. To solve this contradiction, we reconstructed the phylogeny of pepcase gene family. Our result showed that both PTPC and BTPC are derived from an ancestral lineage of gamma-proteobacteriapepcases, possibly via an ancient inter-kingdom horizontal gene transfer (HGT) from bacteria to the eukaryotic common ancestor of plants, protists and cellular slime mold. Our phylogenetic analysis also found 48other pepcase genes originated from inter-kingdom HGTs. These results imply that inter-kingdom HGTs played important roles in the evolution of the pepcase gene family and furthermore that HGTsare a more frequent evolutionary event than previouslythought. PMID:23251445

  10. Multiple inter-kingdom horizontal gene transfers in the evolution of the phosphoenolpyruvate carboxylase gene family.

    Directory of Open Access Journals (Sweden)

    Yingmei Peng

    Full Text Available Pepcase is a gene encoding phosphoenolpyruvate carboxylase that exists in bacteria, archaea and plants,playing an important role in plant metabolism and development. Most plants have two or more pepcase genes belonging to two gene sub-families, while only one gene exists in other organisms. Previous research categorized one plant pepcase gene as plant-type pepcase (PTPC while the other as bacteria-type pepcase (BTPC because of its similarity with the pepcase gene found in bacteria. Phylogenetic reconstruction showed that PTPC is the ancestral lineage of plant pepcase, and that all bacteria, protistpepcase and BTPC in plants are derived from a lineage of pepcase closely related with PTPC in algae. However, their phylogeny contradicts the species tree and traditional chronology of organism evolution. Because the diversification of bacteria occurred much earlier than the origin of plants, presumably all bacterialpepcase derived from the ancestral PTPC of algal plants after divergingfrom the ancestor of vascular plant PTPC. To solve this contradiction, we reconstructed the phylogeny of pepcase gene family. Our result showed that both PTPC and BTPC are derived from an ancestral lineage of gamma-proteobacteriapepcases, possibly via an ancient inter-kingdom horizontal gene transfer (HGT from bacteria to the eukaryotic common ancestor of plants, protists and cellular slime mold. Our phylogenetic analysis also found 48other pepcase genes originated from inter-kingdom HGTs. These results imply that inter-kingdom HGTs played important roles in the evolution of the pepcase gene family and furthermore that HGTsare a more frequent evolutionary event than previouslythought.

  11. Characterization of the distal promoter of the human pyruvate carboxylase gene in pancreatic beta cells.

    Directory of Open Access Journals (Sweden)

    Ansaya Thonpho

    Full Text Available Pyruvate carboxylase (PC is an enzyme that plays a crucial role in many biosynthetic pathways in various tissues including glucose-stimulated insulin secretion. In the present study, we identify promoter usage of the human PC gene in pancreatic beta cells. The data show that in the human, two alternative promoters, proximal and distal, are responsible for the production of multiple mRNA isoforms as in the rat and mouse. RT-PCR analysis performed with cDNA prepared from human liver and islets showed that the distal promoter, but not the proximal promoter, of the human PC gene is active in pancreatic beta cells. A 1108 bp fragment of the human PC distal promoter was cloned and analyzed. It contains no TATA box but possesses two CCAAT boxes, and other putative transcription factor binding sites, similar to those of the distal promoter of rat PC gene. To localize the positive regulatory region in the human PC distal promoter, 5'-truncated and the 25-bp and 15-bp internal deletion mutants of the human PC distal promoter were generated and used in transient transfections in INS-1 832/13 insulinoma and HEK293T (kidney cell lines. The results indicated that positions -340 to -315 of the human PC distal promoter serve as (an activator element(s for cell-specific transcription factor, while the CCAAT box at -71/-67, a binding site for nuclear factor Y (NF-Y, as well as a GC box at -54/-39 of the human PC distal promoter act as activator sequences for basal transcription.

  12. Photosynthetic Characteristics and Heterosis in Transgenic Hybrid Rice with Maize Phosphoenolpyruvate Carboxylase (pepc) Gene

    Institute of Scientific and Technical Information of China (English)

    LI Ji-hang; XIANG Xun-chao; ZHOU Hua-qiang; HE Li-bin; ZHANG Kai-zheng; LI Ping

    2006-01-01

    Three F1 hybrids derived from the sterile rice lines Gang 46A, 776A and 2480A and the improved restorer line Shuhui 881 containing maize phosphoenolpyruvate carboxylase (pepc) gene were used to analyze the effect of pepc gene on the heterosis and photosynthetic characteristics, while the F1 obtained by crossing Shuhui 881 with the above three sterile lines served as controls. The dynamics of photosynthetic characteristics in leaves of three F1 with pepc gene and their controls were determined at the initial-tillering, maxium-tillering, elongation, initial-heading, heading, maturity stages, and other different times after flag leaf fully expanded. The PEPCase activities of the three F1 with pepc gene increased significantly as compared with control plants during the whole developmental stages. Moreover, the net photosynthesis rate (Pn) also increased to certain extent. The data showed that PEPCase activity was significantly correlated to Pn with a correlation coefficient of 0.6081**. The photosynthetic indexes of the three F1 with pepc gene were obviously superior with respective to controls in apparent quantum yield, light compensation point (LCP) and carboxylation efficiency (CE), while the CO2 compensation point (CCP) was lower than that of corresponding control. The Pn of the three F1 with pepc gene at light saturation point (LSP) and CO2 saturation point (CSP) was also higher than that of control plants. In addition, the three F1 with pepc gene had an average increase of 37.10% in grain yields per plant in comparison with control plants. The results indicated that the photosynthetic characteristics of hybrid rice containing pepc gene had been improved to some extent due to the introduction of pepc gene.

  13. Carbon-13 and deuterium isotope effects on the catalytic reactions of biotin carboxylase

    International Nuclear Information System (INIS)

    13C and 2H kinetic isotope effects have been used to investigate the mechanism of enzymic biotin carboxylation. /sup D/(V/K) is 0.50 in 80% D2O at pD 8.0 for the forward reaction and 0.57 at pD 8.5 for the phosphorylation of ADP by carbamoyl phosphate. These values approach the theoretical maximum limit for a reaction in which a proton is transferred from a sulfhydryl to a nitrogen or oxygen base. Therefore, it appears that this portion of the reaction is at or near equilibrium. 13(V/K) at pH 8 is 1.007; the small magnitude of this number suggests that the reaction is almost fully committed by the time the carbon-sensitive steps are reached. There does not appear to be a reverse commitment to the reaction under the conditions in which 13(V/K) was determined. A large forward commitment is consistent with the failure to observe positional isotope exchange from the βγ-bridge position to the β-nonbridge position in [18O4]ATP or washout of 18O from the γ-nonbridge positions. Transfer of 18O from bicarbonate to inorganic phosphate in the forward reaction was clearly observed, however. These observations suggest that biotin carboxylase exists in two distinct forms which differ in the protonation states of the two active-site bases, one of which is a sulfhydryl. Only when the sulfhydryl is ionized and the second base protonated can catalysis take place. Carboxylation of biotin is postulated to occur via a pathway in which carboxyphosphate is formed by nucleophilic attack of bicarbonate on ATP. Decarboxylation of carboxyphosphate in the active site generates CO2, which serves to carboxylate the isourea tautomer of biotin that is generated by the removal of the proton on N1' by the ionized sulfhydryl

  14. Identification of Interactions between Abscisic Acid and Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase.

    Directory of Open Access Journals (Sweden)

    Marek M Galka

    Full Text Available Abscisic acid ((+-ABA is a phytohormone involved in the modulation of developmental processes and stress responses in plants. A chemical proteomics approach using an ABA mimetic probe was combined with in vitro assays, isothermal titration calorimetry (ITC, x-ray crystallography and in silico modelling to identify putative (+-ABA binding-proteins in crude extracts of Arabidopsis thaliana. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco was identified as a putative ABA-binding protein. Radiolabelled-binding assays yielded a Kd of 47 nM for (+-ABA binding to spinach Rubisco, which was validated by ITC, and found to be similar to reported and experimentally derived values for the native ribulose-1,5-bisphosphate (RuBP substrate. Functionally, (+-ABA caused only weak inhibition of Rubisco catalytic activity (Ki of 2.1 mM, but more potent inhibition of Rubisco activation (Ki of ~ 130 μM. Comparative structural analysis of Rubisco in the presence of (+-ABA with RuBP in the active site revealed only a putative low occupancy (+-ABA binding site on the surface of the large subunit at a location distal from the active site. However, subtle distortions in electron density in the binding pocket and in silico docking support the possibility of a higher affinity (+-ABA binding site in the RuBP binding pocket. Overall we conclude that (+-ABA interacts with Rubisco. While the low occupancy (+-ABA binding site and weak non-competitive inhibition of catalysis may not be relevant, the high affinity site may allow ABA to act as a negative effector of Rubisco activation.

  15. Effects of phosphoenolpyruvate carboxylase desensitization on glutamic acid production in Corynebacterium glutamicum ATCC 13032.

    Science.gov (United States)

    Wada, Masaru; Sawada, Kazunori; Ogura, Kotaro; Shimono, Yuta; Hagiwara, Takuya; Sugimoto, Masakazu; Onuki, Akiko; Yokota, Atsushi

    2016-02-01

    Phosphoenolpyruvate carboxylase (PEPC) in Corynebacterium glutamicum ATCC13032, a glutamic-acid producing actinobacterium, is subject to feedback inhibition by metabolic intermediates such as aspartic acid and 2-oxoglutaric acid, which implies the importance of PEPC in replenishing oxaloacetic acid into the TCA cycle. Here, we investigated the effects of feedback-insensitive PEPC on glutamic acid production. A single amino-acid substitution in PEPC, D299N, was found to relieve the feedback control by aspartic acid, but not by 2-oxoglutaric acid. A simple mutant, strain R1, having the D299N substitution in PEPC was constructed from ATCC 13032 using the double-crossover chromosome replacement technique. Strain R1 produced glutamic acid at a concentration of 31.0 g/L from 100 g/L glucose in a jar fermentor culture under biotin-limited conditions, which was significantly higher than that of the parent, 26.0 g/L (1.19-fold), indicative of the positive effect of desensitized PEPC on glutamic acid production. Another mutant, strain DR1, having both desensitized PEPC and PYK-gene deleted mutations, was constructed in a similar manner using strain D1 with a PYK-gene deleted mutation as the parent. This mutation had been shown to enhance glutamic acid production in our previous study. Although marginal, strain D1 produced higher glutamic acid, 28.8 g/L, than ATCC13032 (1.11-fold). In contrast, glutamic acid production by strain DR-1 was elevated up to 36.9 g/L, which was 1.42-fold higher than ATCC13032 and significantly higher than the other three strains. The results showed a synergistic effect of these two mutations on glutamic acid production in C. glutamicum. PMID:26168906

  16. Epigenetic regulation of pyruvate carboxylase gene expression in the postpartum liver.

    Science.gov (United States)

    Walker, C G; Crookenden, M A; Henty, K M; Handley, R R; Kuhn-Sherlock, B; White, H M; Donkin, S S; Snell, R G; Meier, S; Heiser, A; Loor, J J; Mitchell, M D; Roche, J R

    2016-07-01

    Hepatic gluconeogenesis is essential for maintenance of whole body glucose homeostasis and glucose supply for mammary lactose synthesis in the dairy cow. Upregulation of the gluconeogenic enzyme pyruvate carboxylase (PC) during the transition period is vital in the adaptation to the greater glucose demands associated with peripartum lactogenesis. The objective of this study was to determine if PC transcription in hepatocytes is regulated by DNA methylation and if treatment with a nonsteroidal anti-inflammatory drug (NSAID) alters methylation of an upstream DNA sequence defined as promoter 1. Dairy cows were left untreated (n=20), or treated with a NSAID during the first 5 d postcalving (n=20). Liver was biopsied at d 7 precalving and d 7, 14, and 28 postcalving. Total PC and transcript specific gene expression was quantified using quantitative PCR and DNA methylation of promoter 1 was quantified using bisulfite Sanger sequencing. Expression of PC changed over the transition period, with increased expression postcalving occurring concurrently with increased circulating concentration of nonesterified fatty acids. The DNA methylation percentage was variable at all sites quantified and ranged from 21 to 54% across the 15 CpG dinucleotides within promoter 1. The DNA methylation at wk 1 postcalving, however, was not correlated with gene expression of promoter 1-regulated transcripts and we did not detect an effect of NSAID treatment on DNA methylation or PC gene expression. Our results do not support a role for DNA methylation in regulating promoter 1-driven gene expression of PC at wk 1 postcalving. Further research is required to determine the mechanisms regulating increased PC expression over the transition period. PMID:27085418

  17. Ribulose-1,5-bisphosphate carboxylase/oxygenase gene expression and diversity of Lake Erie planktonic microorganisms.

    OpenAIRE

    Xu, H.H.; Tabita, F R

    1996-01-01

    Carbon dioxide fixation is carried out primarily through the Calvin-Benson-Bassham reductive pentose phosphate cycle, in which ribulose-1, 5-bisphosphate carboxylase/oxygenase (RubisCO) is the key enzyme. The primary structure of the large subunit of form I RubisCO is well conserved; however, four distinct types, A, B, C, and D, may be distinguished, with types A and B and types C and D more closely related to one another. To better understand the environmental regulation of RubisCO in Lake E...

  18. A Novel Approach to Functional Analysis of the Ribulose Bisphosphate Carboxylase Small Subunit Gene by Agrobacterium-Mediated Gene Silencing

    Institute of Scientific and Technical Information of China (English)

    Xiao-Fu Zhou; Peng-Da Ma; Ren-Hou Wang; Bo Liu; Xing-Zhi Wang

    2006-01-01

    A novel approach to virus-induced post-transcriptional gene silencing for studying the function of the ribulose bisphosphate carboxylase small subunlt (rbcS) gene was established and optimized using potato virus X vector and Nicotiana benthamiana as experimental material. The analysis of silencing phenomena,transcriptional level, protein expression, and pigment measurement showed that the expression of the rbcS endogenous gene was inactivated by the expression of a 500-bp homologous cDNA fragment carried in the virus vector.

  19. Demonstration of a functional requirement for the carbamate nitrogen of ribulosebisphosphate carboxylase/oxygenase by chemical rescue

    International Nuclear Information System (INIS)

    Ribulosebisphosphate carboxylase/oxygenase is reversibly activated by the reaction of Co2 with a specific lysyl residue to form a carbamate that coordinates an essential Mg2+ cation. Surprisingly, the Lys191→Cys mutant protein, in the presence of Co2 and Mg2+ exhibits tight binding of the reaction intermediate analogue 2-carboxyarabinitol bisphosphate a property normally equated with effective coordination of the Mg2+ by the carbamate. Catalytic ineptness of the Cys191 mutant protein, despite its ability to coordinate Mg2+ properly, might be due to the absence of the carbamate nitrogen. To investigate this possibility, the authors have evaluated the ability of exogenous amines to restore catalytic activity to the mutant protein. Significantly, the Cys191 protein manifests ribulose bisphosphate dependent fixation of 14CO2 when incubated with aminomethanewsulfonate but not ethanesulfonate. This novel activity reflects a Km value for ribulose bisphosphate which is not markedly perturbed relative to wild-type enzyme, a Km for Mg2+ which is in fact decreased 10-fold, and rate saturation with respect to aminomethanesulfonate. Chromatographic and spectrophotometric analyses reveal the product of CO2 fixation to be D-3-phosphoglycerate while turnover of [1-3H]ribulose bisphosphate into [3H]phosphoglycolate confirms oxygenase activity. The authors conclude that aminomethanesulfonate restored ribulosebisphosphate carboxylase/oxygenase activities to the Cys191 mutant protein by providing a nitrogenous function which satisfies a catalytic demand normally met by the carbamate nitrogen of Lys191

  20. Simple determination of the CO2/O2 specificity of Ribulose-1,5-bisphosphate carboxylase/oxygenase by the specific radioactivity of [14C] glycerate 3-phosphate

    International Nuclear Information System (INIS)

    A new method is presented for measurement of the CO2/O2 specificity factor of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). The [14C]3-phosphoglycerate (PGA) from the Rubisco carboxylase reaction and its dilution by the Rubisco oxygenase reaction was monitored by directly measuring the specific radioactivity of PGA. 14CO2 fixation with Rubisco occurred under two reaction conditions: carboxylase with oxygenase with 40 micromolar CO2 in O2-saturated water and carboxylase only with 160 micromolar CO2 under N2. Detection of the specific radioactivity used the amount of PGA as obtained from the peak area, which was determined by pulsed amperometry following separation by high-performance anion exchange chromatography and the radioactive counts of the [14C]PGA in the same peak. The specificity factor of Rubisco from spinach (Spinacia oleracea L.) (93 ± 4), from the green alga Chlamydomonas reinhardtii (66 ± 1), and from the photosynthetic bacterium Rhodospirillum rubrum (13) were comparable with the published values measured by different methods

  1. A conformational investigation of propeptide binding to the integral membrane protein γ-glutamyl carboxylase using nanodisc hydrogen exchange mass spectrometry

    DEFF Research Database (Denmark)

    Parker, Christine H; Morgan, Christopher R; Rand, Kasper Dyrberg;

    2014-01-01

    Gamma (γ)-glutamyl carboxylase (GGCX) is an integral membrane protein responsible for the post-translational catalytic conversion of select glutamic acid (Glu) residues to γ-carboxy glutamic acid (Gla) in vitamin K-dependent (VKD) proteins. Understanding the mechanism of carboxylation and the rol...

  2. Cloning and characterization of the gene product of the form II ribulose-1,5-bisphosphate carboxylase gene of Rhodopseudomonas sphaeroides.

    OpenAIRE

    Muller, E D; Chory, J; Kaplan, S

    1985-01-01

    We report the cloning and characterization of the gene product of the gene for the form II ribulose bisphosphate carboxylase from Rhodopseudomonas sphaeroides. We present evidence that the form II enzyme is encoded by a single gene in R. sphaeroides; however, this gene does hybridize to a second chromosomal locus.

  3. Serine-15 is the regulatory seryl-phosphorylation site in C4-leaf phosphoenolpyruvate carboxylase (PEPCase) from maize

    International Nuclear Information System (INIS)

    The 32P-labeled regulatory site phosphopeptide was purified from a tryptic digest of in vitro phosphorylated/activated dark-form PEPCase by metal ion affinity and reversed-phase chromatography and subjected to automated Edman degradation analysis. The amino acid sequence of this phosphoseryl peptide is His-His-Ser(P)-Ile-Asp-Ala-Gln-Leu-Arg. This nonapeptide, which corresponds exactly to residues 13-21 in the deduced primary sequence of the maize leaf carboxylase, is far removed from a recently identified active-site cysteine (Cys-553) in the C-terminal region of the primary structure. Comparative analysis of the deduced N-terminal sequences of C3, C4, and CAM leaf PEPCases suggests that the motif of Lys/Arg-X-X-Ser is an important structural requirement of the C4- and CAM-leaf protein-serine kinases

  4. Serine-15 is the regulatory seryl-phosphorylation site in C sub 4 -leaf phosphoenolpyruvate carboxylase (PEPCase) from maize

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Jinan; Chollet, R. (Univ. of Nebraska, Lincoln (USA))

    1990-05-01

    The {sup 32}P-labeled regulatory site phosphopeptide was purified from a tryptic digest of in vitro phosphorylated/activated dark-form PEPCase by metal ion affinity and reversed-phase chromatography and subjected to automated Edman degradation analysis. The amino acid sequence of this phosphoseryl peptide is His-His-Ser(P)-Ile-Asp-Ala-Gln-Leu-Arg. This nonapeptide, which corresponds exactly to residues 13-21 in the deduced primary sequence of the maize leaf carboxylase, is far removed from a recently identified active-site cysteine (Cys-553) in the C-terminal region of the primary structure. Comparative analysis of the deduced N-terminal sequences of C{sub 3}, C{sub 4}, and CAM leaf PEPCases suggests that the motif of Lys/Arg-X-X-Ser is an important structural requirement of the C{sub 4}- and CAM-leaf protein-serine kinases.

  5. Phosphorylation-dephosphorylation process as a probable mechanism for the diurnal regulatory changes of phosphoenolpyruvate carboxylase in CAM plants.

    Science.gov (United States)

    Brulfert, J; Vidal, J; Le Marechal, P; Gadal, P; Queiroz, O; Kluge, M; Kruger, I

    1986-04-14

    Day and night forms of phosphoenolpyruvate carboxylase (EC 4.1.1.31) (PEPC) were extracted from leaves of the CAM plants Kalanchoe daigremontiana, K. tubiflora and K. blossfeldiana previously fed with [32P] labelled phosphate solution. A one-step immunochemical purification followed by SDS polyacrylamide gel electrophoresis and autoradiography showed that, in all species, the night form of the enzyme was phosphorylated and not the day form. Limited acid hydrolysis of the night form and two-dimensional separation identified predominantly labelled phosphoserine and phosphothreonine. In vitro addition of exogenous acid phosphatase (EC 3.1.3.2) to desalted night form-containing extracts resulted within 30 min in a shift in PEPC enzymic properties similar to the in vivo changes from night to day form. It is suggested that phosphorylation-dephosphorylation of the enzyme could be the primary in vivo process which might explain the observed rhythmicity of enzymic properties. PMID:3707571

  6. Differential transcription and message stability of two genes encoding soybean ribulose 1,5-bisphosphate carboxylase small subunit

    International Nuclear Information System (INIS)

    The expression of two closely related soybean ribulose bisphosphate carboxylase small subunit (Rubisco ss) genes, SRS1 and SRS4, has been compared. These genes account for approximately 2-4% of the total transcription in light grown leaves, SRS4 being twice as transcriptionally active as SRS1. The transcription of these genes is reduced more than 30 fold after a pulse of far-red light or extended periods of darkness. When etiolated seedlings are shifted to the light the transcription of both genes increases 30-50 fold. Despite this 30-fold range in transcriptional expression the steady state mRNA levels in light and dark grown tissue differ by less than 8 fold. This suggests that the mRNAs are less stable in light grown tissue. 38 refs., 5 figs

  7. Determination of ploidy level and isolation of genes encoding acetyl-CoA carboxylase in Japanese Foxtail (Alopecurus japonicus.

    Directory of Open Access Journals (Sweden)

    Hongle Xu

    Full Text Available Ploidy level is important in biodiversity studies and in developing strategies for isolating important plant genes. Many herbicide-resistant weed species are polyploids, but our understanding of these polyploid weeds is limited. Japanese foxtail, a noxious agricultural grass weed, has evolved herbicide resistance. However, most studies on this weed have ignored the fact that there are multiple copies of target genes. This may complicate the study of resistance mechanisms. Japanese foxtail was found to be a tetraploid by flow cytometer and chromosome counting, two commonly used methods in the determination of ploidy levels. We found that there are two copies of the gene encoding plastidic acetyl-CoA carboxylase (ACCase in Japanese foxtail and all the homologous genes are expressed. Additionally, no difference in ploidy levels or ACCase gene copy numbers was observed between an ACCase-inhibiting herbicide-resistant and a herbicide-sensitive population in this study.

  8. Cloning, Expression and Purification of Wheat Acetyl-CoA Carboxylases CT Domain in E.coil

    Institute of Scientific and Technical Information of China (English)

    WANG Rui-jian; YANG Xue-ying; ZHENG Liang-yu; YANG Ye; GAO Gui; CAO Shu-gui

    2008-01-01

    The entire gene of carboxyltransferase(CT) domain of acetyl-CoA carboxylase(ACCase) from Chinese Spring wheat(CSW) plastid was cloned firstly,and the 2.3 kb gene was inserted into PET28a+ vector and expressed in E.coil in a soluble state.The (His)6 fusion protein was identified by SDS-PAGE and Western blot.The recombinant protein was purified by affinity chromatography,and the calculated molecular mass(Mr) was 88000.The results of the sequence analysis indicate that the cloned gene(GeneBank accession No.EU124675) was a supplement and revision of the reported ACCase CT partial cDNA from Chinese Spring wheat plastid.The recombinant protein will be significant for us to investigate the recognizing mechanism between ACCase and herbicides,and further to screen new herbicides.

  9. Effect of low temperature stress on the transcription of ribulose-1, 5-bisphosphate carboxylase in rice seedlings

    International Nuclear Information System (INIS)

    The seeds of ri e (oryza sativa. cv. IR 8) were grown in the growth chambers having 14 hours day length and temperature 25 deg. C) under same photo period to observe low temperature effect. After 10 days the fourth leaf of each plant was excised and immediately killed in liquid nitrogen and then used for the extraction of total RNA by GTC method. This RNA was used to estimate the amount of mRNAs responsible for the transcription of lage subunit (LSU) and small subunit (|SSU) of the Ribulose-1, 5-bisphosphate carboxylase (RuPBC) by northern blot and dot blot hybridization using cDNA probes labeled with /sup 32/P. It was observed that amount of mRNAs (LSU and SSU mRNAs) or RuBPC decreased under low temperature stress indicating that transcription of RuBPC was affected. (author)

  10. A 3-methylcrotonyl-CoA carboxylase deficient human skin fibroblast transcriptome reveals underlying mitochondrial dysfunction and oxidative stress.

    Science.gov (United States)

    Zandberg, L; van Dyk, H C; van der Westhuizen, F H; van Dijk, A A

    2016-09-01

    Isolated 3-methylcrotonyl-CoA carboxylase (MCC) deficiency is an autosomal recessive inherited metabolic disease of leucine catabolism with a highly variable phenotype. Apart from extensive mutation analyses of the MCCC1 and MCCC2 genes encoding 3-methylcrotonyl-CoA carboxylase (EC 6.4.1.4), molecular data on MCC deficiency gene expression studies in human tissues is lacking. For IEMs, unbiased '-omics' approaches are starting to reveal the secondary cellular responses to defects in biochemical pathways. Here we present the first whole genome expression profile of immortalized cultured skin fibroblast cells of two clinically affected MCC deficient patients and two healthy individuals generated using Affymetrix(®)HuExST1.0 arrays. There were 16191 significantly differentially expressed transcript IDs of which 3591 were well annotated and present in the predefined knowledge database of Ingenuity Pathway Analysis software used for downstream functional analyses. The most noticeable feature of this MCCA deficient skin fibroblast transcriptome was the typical genetic hallmark of mitochondrial dysfunction, decreased antioxidant response and disruption of energy homeostasis, which was confirmed by mitochondrial functional analyses. The MCC deficient transcriptome seems to predict oxidative stress that could alter the complex secondary cellular response that involve genes of the glycolysis, the TCA cycle, OXPHOS, gluconeogenesis, β-oxidation and the branched-chain fatty acid metabolism. An important emerging insight from this human MCCA transcriptome in combination with previous reports is that chronic exposure to the primary and secondary metabolites of MCC deficiency and the resulting oxidative stress might impact adversely on the quality of life and energy levels, irrespective of whether MCC deficient individuals are clinically affected or asymptomatic. PMID:27417235

  11. Comparative modeling and molecular dynamics suggest high carboxylase activity of the Cyanobium sp. CACIAM14 RbcL protein.

    Science.gov (United States)

    Siqueira, Andrei Santos; Lima, Alex Ranieri Jerônimo; Dall'Agnol, Leonardo Teixeira; de Azevedo, Juliana Simão Nina; da Silva Gonçalves Vianez, João Lídio; Gonçalves, Evonnildo Costa

    2016-03-01

    Rubisco catalyzes the first step reaction in the carbon fixation pathway, bonding atmospheric CO2/O2 to ribulose 1,5-bisphosphate; it is therefore considered one of the most important enzymes in the biosphere. Genetic modifications to increase the carboxylase activity of rubisco are a subject of great interest to agronomy and biotechnology, since this could increase the productivity of biomass in plants, algae and cyanobacteria and give better yields in crops and biofuel production. Thus, the aim of this study was to characterize in silico the catalytic domain of the rubisco large subunit (rbcL gene) of Cyanobium sp. CACIAM14, and identify target sites to improve enzyme affinity for ribulose 1,5-bisphosphate. A three-dimensional model was built using MODELLER 9.14, molecular dynamics was used to generate a 100 ns trajectory by AMBER12, and the binding free energy was calculated using MM-PBSA, MM-GBSA and SIE methods with alanine scanning. The model obtained showed characteristics of form-I rubisco, with 15 beta sheets and 19 alpha helices, and maintained the highly conserved catalytic site encompassing residues Lys175, Lys177, Lys201, Asp203, and Glu204. The binding free energy of the enzyme-substrate complexation of Cyanobium sp. CACIAM14 showed values around -10 kcal mol(-1) using the SIE method. The most important residues for the interaction with ribulose 1,5-bisphosphate were Arg295 followed by Lys334. The generated model was successfully validated, remaining stable during the whole simulation, and demonstrated characteristics of enzymes with high carboxylase activity. The binding analysis revealed candidates for directed mutagenesis sites to improve rubisco's affinity. PMID:26936271

  12. AMPK activation represses the human gene promoter of the cardiac isoform of acetyl-CoA carboxylase: Role of nuclear respiratory factor-1

    International Nuclear Information System (INIS)

    Research highlights: → AMPK inhibits acetyl-CoA carboxylase beta gene promoter activity. → Nuclear respiratory factor-1 inhibits acetyl-CoA carboxylase beta promoter activity. → AMPK regulates acetyl-CoA carboxylase beta at transcriptional level. -- Abstract: The cardiac-enriched isoform of acetyl-CoA carboxylase (ACCβ) produces malonyl-CoA, a potent inhibitor of carnitine palmitoyltransferase-1. AMPK inhibits ACCβ activity, lowering malonyl-CoA levels and promoting mitochondrial fatty acid β-oxidation. Previously, AMPK increased promoter binding of nuclear respiratory factor-1 (NRF-1), a pivotal transcriptional modulator controlling gene expression of mitochondrial proteins. We therefore hypothesized that NRF-1 inhibits myocardial ACCβ promoter activity via AMPK activation. A human ACCβ promoter-luciferase construct was transiently transfected into neonatal cardiomyocytes ± a NRF-1 expression construct. NRF-1 overexpression decreased ACCβ gene promoter activity by 71 ± 4.6% (p < 0.001 vs. control). Transfections with 5'-end serial promoter deletions revealed that NRF-1-mediated repression of ACCβ was abolished with a pPIIβ-18/+65-Luc deletion construct. AMPK activation dose-dependently reduced ACCβ promoter activity, while NRF-1 addition did not further decrease it. We also investigated NRF-1 inhibition in the presence of upstream stimulatory factor 1 (USF1), a known transactivator of the human ACCβ gene promoter. Here NRF-1 blunted USF1-dependent induction of ACCβ promoter activity by 58 ± 7.5% (p < 0.001 vs. control), reversed with a dominant negative NRF-1 construct. NRF-1 also suppressed endogenous USF1 transcriptional activity by 55 ± 6.2% (p < 0.001 vs. control). This study demonstrates that NRF-1 is a novel transcriptional inhibitor of the human ACCβ gene promoter in the mammalian heart. Our data extends AMPK regulation of ACCβ to the transcriptional level.

  13. Influence of nitrogen enrichment on size-fractionated in vitro carboxylase activities of phytoplankton from Thau Lagoon (Coastal Mediterranean Lagoon, France)

    OpenAIRE

    Fouilland, Eric; Descolas Gros, Chantal; Collos, Yves; Vaquer A, André; Souchu, Philippe; Gasc, Anne; Bibent, Bertrand; Pons, Virginie

    2002-01-01

    The influence of dissolved inorganic and organic nitrogen (DIN and DON) enrichments on pools of enzymes responsible for CO2 fixation by the Calvin-Benson (Rubisco) and beta-carboxylation pathways (beta-carboxylases) were studied in a natural plankton assemblage. The plankton community from a coastal Mediterranean lagoon were incubated in situ for 24 h with initially ammonium, nitrate and DON (taurine) enrichments and compared to a control without any enrichment. An increase of small picophyto...

  14. Measurement of Acylcarnitine Substrate to Product Ratios Specific to Biotin-Dependent Carboxylases Offers a Combination of Indicators of Biotin Status in Humans12

    OpenAIRE

    Bogusiewicz, Anna; Horvath, Thomas D; Stratton, Shawna L.; Mock, Donald M; Boysen, Gunnar

    2012-01-01

    This work describes a novel liquid chromatography tandem MS (LC-MS/MS) method for the determination of ratios of acylcarnitines arising from acyl-CoA substrates and products that reflect metabolic disturbances caused by marginal biotin deficiency. The urinary ratios reflecting reduced activities of biotin-dependent enzymes include the following: 1) the ratio of 3-hydroxyisovalerylcarnitine : 3-methylglutarylcarnitine (3HIAc : MGc) for methylcrotonyl-CoA carboxylase; 2) the ratio of propionylc...

  15. Acetyl-CoA carboxylase inhibition by ND-630 reduces hepatic steatosis, improves insulin sensitivity, and modulates dyslipidemia in rats.

    Science.gov (United States)

    Harriman, Geraldine; Greenwood, Jeremy; Bhat, Sathesh; Huang, Xinyi; Wang, Ruiying; Paul, Debamita; Tong, Liang; Saha, Asish K; Westlin, William F; Kapeller, Rosana; Harwood, H James

    2016-03-29

    Simultaneous inhibition of the acetyl-CoA carboxylase (ACC) isozymes ACC1 and ACC2 results in concomitant inhibition of fatty acid synthesis and stimulation of fatty acid oxidation and may favorably affect the morbidity and mortality associated with obesity, diabetes, and fatty liver disease. Using structure-based drug design, we have identified a series of potent allosteric protein-protein interaction inhibitors, exemplified by ND-630, that interact within the ACC phosphopeptide acceptor and dimerization site to prevent dimerization and inhibit the enzymatic activity of both ACC isozymes, reduce fatty acid synthesis and stimulate fatty acid oxidation in cultured cells and in animals, and exhibit favorable drug-like properties. When administered chronically to rats with diet-induced obesity, ND-630 reduces hepatic steatosis, improves insulin sensitivity, reduces weight gain without affecting food intake, and favorably affects dyslipidemia. When administered chronically to Zucker diabetic fatty rats, ND-630 reduces hepatic steatosis, improves glucose-stimulated insulin secretion, and reduces hemoglobin A1c (0.9% reduction). Together, these data suggest that ACC inhibition by representatives of this series may be useful in treating a variety of metabolic disorders, including metabolic syndrome, type 2 diabetes mellitus, and fatty liver disease. PMID:26976583

  16. INFLUENCE OF NACL SALINITY ON THE ACTIVITY OF RIBULOSE 1, 5-BISPHOSPHATE CARBOXYLASE IN THREE LEAFY VEGETABLES

    Directory of Open Access Journals (Sweden)

    Anjali Ratnakar

    2015-06-01

    Full Text Available Salinity is one of the major factors which have an adverse effect on crop growth. Stress caused due to excessive accumulation of salts results in various physiological and biochemical changes in plants. Due to their nutritional value, leafy vegetables constitute an important part of our daily diet. In the present investigation, effect of NaCl salinity on the activity of ribulose 1,5–bisphosphate carboxylase in three leafy vegetables was studied. Seeds of leafy vegetables were sown in earthen pots and were subjected to different levels of saline water (NaCl treatment. Control plants were irrigated with tap water. Treatments started after the seedling emergence and continued till the plants were 45 day old. Mature leaves of these plants were harvested and used for the studies. The activity of ribulose 1,5-bisphosphate in all the three leafy vegetables was observed to decrease gradually with increase in the concentration of NaCl in the growth medium.

  17. The source and characteristics of chemiluminescence associated with the oxygenase reaction catalyzed by Mn(2+)-ribulosebisphosphate carboxylase.

    Science.gov (United States)

    Lilley, R M; Riesen, H; Andrews, T J

    1993-07-01

    We confirm the observation of Mogel and McFadden (Mogel, S.N., and McFadden, B. A. (1990) Biochemistry 29, 8333-8337) that ribulosebisphosphate carboxylase/oxygenase (rubisco) exhibits chemiluminescence while catalyzing its oxygenase reaction in the presence of Mn2+. However, our results with the spinach and Rhodospirillum rubrum enzymes differ markedly in the following respects. 1) Chemiluminescence intensity was directly proportional to enzyme concentration and behaved as if representing the rate of oxygenase catalysis. 2) The wavelength spectrum peaked at about 770 nm and extended beyond 810 nm. This seems inconsistent with chemiluminescence generated by simultaneous decay of pairs of singlet O2 molecules. It is consistent with manganese(II) luminescence and we discuss its possible sources. The time course of chemiluminescence (resolution, 0.25 s) was distinctively different for spinach and R. rubrum enzymes during the initial 5 s of catalysis, with the bacterial enzyme exhibiting a pronounced initial "burst." Chemiluminescence by the spinach enzyme responded to substrate concentrations in a manner consistent with known oxygenase properties, exhibiting Michaelis-Menten kinetics with ribulose-1,5-bisphosphate (Km 400 nM). Chemiluminescence required carbamylated enzyme with Mn2+ bound at the active site (activation energy, -57.1 KJ.mol-1). As an indicator of oxygenase activity, chemiluminescence represents an improvement over oxygen electrode measurements in response time and sensitivity by factors of at least 100. PMID:8314755

  18. Promotive Effect of Low Concentrations of NaHSO3 on Photophosphorylation and Photosynthesis in Phosphoenolpyruvate Carboxylase Transgenic Rice Leaves

    Institute of Scientific and Technical Information of China (English)

    Ben-Hua JI; Hong-He TAN; Rong ZHOU; De-Mao JIAO; Yun-Gang SHEN

    2005-01-01

    Spraying a 1-2 mmol/L solution of NaHSO3 on the leaves of wild-type rice (Oryza sativa L.)Kitaake (WT), phosphoenolpyruvate carboxylase (PEPC) transgenic (PC) rice and PEPC+phosphate dikinase (PPDK) transgenic rice (PC+PK), in which the germplasm was transformed with wild-type Kitaake as the gene receptor, resulted in an enhancement of the net photosynthetic rate by 23.0%, 28.8%, and 34.4%,respectively, for more than 3 d. It was also observed that NaHSO3 application caused an increase in the ATP content in leaves. Spraying PMS (a cofactor catalysing the photophosphorylation cycle) and NaHSO3 separately or together on leaves resulted in an increase in photosynthesis with all treatments. There was no additional effect on photosynthetic rate when the mixture was applied, suggesting that the mechanism by which NaHSO3 promotes photosynthesis is similar to the mechanism by which PMS acts and that both of compounds enhanced the supply of ATP. After spraying a solution of NaHSO3 on leaves, compared with the WT Kitaake rice, a greater enhancement of net photosynthetic rate was observed in PEPC transgenic (PC) and PEPC+PPDK transgenic (PC+PK) rice, with the greatest increase being observed in the latter group. Therefore ATP supply may become the limiting factor that concentrates CO2 in rice leaves transformed with an exogenous PEPC gene and exogenous PEPC+PPDK genes.

  19. Osteoblast-Specific γ-Glutamyl Carboxylase-Deficient Mice Display Enhanced Bone Formation With Aberrant Mineralization.

    Science.gov (United States)

    Azuma, Kotaro; Shiba, Sachiko; Hasegawa, Tomoka; Ikeda, Kazuhiro; Urano, Tomohiko; Horie-Inoue, Kuniko; Ouchi, Yasuyoshi; Amizuka, Norio; Inoue, Satoshi

    2015-07-01

    Vitamin K is a fat-soluble vitamin that is necessary for blood coagulation. In addition, it has bone-protective effects. Vitamin K functions as a cofactor of γ-glutamyl carboxylase (GGCX), which activates its substrates by carboxylation. These substrates are found throughout the body and examples include hepatic blood coagulation factors. Furthermore, vitamin K functions as a ligand of the nuclear receptor known as steroid and xenobiotic receptor (SXR) and its murine ortholog, pregnane X receptor (PXR). We have previously reported on the bone-protective role of SXR/PXR signaling by demonstrating that systemic Pxr-knockout mice displayed osteopenia. Because systemic Ggcx-knockout mice die shortly after birth from severe hemorrhage, the GGCX-mediated effect of vitamin K on bone metabolism has been difficult to evaluate. In this work, we utilized Ggcx-floxed mice to generate osteoblast-specific GGCX-deficient (Ggcx(Δobl/Δobl)) mice by crossing them with Col1-Cre mice. The bone mineral density (BMD) of Ggcx(Δobl/Δobl) mice was significantly higher than that of control Col1-Cre (Ggcx(+/+)) mice. Histomorphometrical analysis of trabecular bones in the proximal tibia showed increased osteoid volume and a higher rate of bone formation in Ggcx(Δobl/Δobl) mice. Histomorphometrical analysis of cortical bones revealed a thicker cortical width and a higher rate of bone formation in Ggcx(Δobl/Δobl) mice. Electron microscopic examination revealed disassembly of mineralized nodules and aberrant calcification of collagen fibers in Ggcx(Δobl/Δobl) mice. The mechanical properties of bones from Ggcx(Δobl/Δobl) mice tended to be stronger than those from control Ggcx(+/+) mice. These results suggest that GGCX in osteoblasts functions to prevent abnormal mineralization in bone formation, although this function may not be a prerequisite for the bone-protective effect of vitamin K. PMID:25600070

  20. Insights into the carboxyltransferase reaction of pyruvate carboxylase from the structures of bound product and intermediate analogs.

    Science.gov (United States)

    Lietzan, Adam D; St Maurice, Martin

    2013-11-15

    Pyruvate carboxylase (PC) is a biotin-dependent enzyme that catalyzes the MgATP- and bicarbonate-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in central metabolism. The carboxyltransferase (CT) domain of PC catalyzes the transfer of a carboxyl group from carboxybiotin to the accepting substrate, pyruvate. It has been hypothesized that the reactive enolpyruvate intermediate is stabilized through a bidentate interaction with the metal ion in the CT domain active site. Whereas bidentate ligands are commonly observed in enzymes catalyzing reactions proceeding through an enolpyruvate intermediate, no bidentate interaction has yet been observed in the CT domain of PC. Here, we report three X-ray crystal structures of the Rhizobium etli PC CT domain with the bound inhibitors oxalate, 3-hydroxypyruvate, and 3-bromopyruvate. Oxalate, a stereoelectronic mimic of the enolpyruvate intermediate, does not interact directly with the metal ion. Instead, oxalate is buried in a pocket formed by several positively charged amino acid residues and the metal ion. Furthermore, both 3-hydroxypyruvate and 3-bromopyruvate, analogs of the reaction product oxaloacetate, bind in an identical manner to oxalate suggesting that the substrate maintains its orientation in the active site throughout catalysis. Together, these structures indicate that the substrates, products and intermediates in the PC-catalyzed reaction are not oriented in the active site as previously assumed. The absence of a bidentate interaction with the active site metal appears to be a unique mechanistic feature among the small group of biotin-dependent enzymes that act on α-keto acid substrates. PMID:24157795

  1. Phylogenetic Analysis of Nucleus-Encoded Acetyl-CoA Carboxylases Targeted at the Cytosol and Plastid of Algae.

    KAUST Repository

    Huerlimann, Roger

    2015-07-01

    The understanding of algal phylogeny is being impeded by an unknown number of events of horizontal gene transfer (HGT), and primary and secondary/tertiary endosymbiosis. Through these events, previously heterotrophic eukaryotes developed photosynthesis and acquired new biochemical pathways. Acetyl-CoA carboxylase (ACCase) is a key enzyme in the fatty acid synthesis and elongation pathways in algae, where ACCase exists in two locations (cytosol and plastid) and in two forms (homomeric and heteromeric). All algae contain nucleus-encoded homomeric ACCase in the cytosol, independent of the origin of the plastid. Nucleus-encoded homomeric ACCase is also found in plastids of algae that arose from a secondary/tertiary endosymbiotic event. In contrast, plastids of algae that arose from a primary endosymbiotic event contain heteromeric ACCase, which consists of three nucleus-encoded and one plastid-encoded subunits. These properties of ACCase provide the potential to inform on the phylogenetic relationships of hosts and their plastids, allowing different hypothesis of endosymbiotic events to be tested. Alveolata (Dinoflagellata and Apicomplexa) and Chromista (Stramenopiles, Haptophyta and Cryptophyta) have traditionally been grouped together as Chromalveolata, forming the red lineage. However, recent genetic evidence groups the Stramenopiles, Alveolata and green plastid containing Rhizaria as SAR, excluding Haptophyta and Cryptophyta. Sequences coding for plastid and cytosol targeted homomeric ACCases were isolated from Isochrysis aff. galbana (TISO), Chromera velia and Nannochloropsis oculata, representing three taxonomic groups for which sequences were lacking. Phylogenetic analyses show that cytosolic ACCase strongly supports the SAR grouping. Conversely, plastidial ACCase groups the SAR with the Haptophyta, Cryptophyta and Prasinophyceae (Chlorophyta). These two ACCase based, phylogenetic relationships suggest that the plastidial homomeric ACCase was acquired by the

  2. Decline of activity and quantity of ribulose bisphosphate carboxylase/oxygenase and net photosynthesis in ozone-treated potato foliage

    Energy Technology Data Exchange (ETDEWEB)

    Dann, M.S.; Pell, E.J. (Pennsylvania State Univ., University Park (USA))

    1989-09-01

    The effect of ozone (O{sub 3}) on ribulose bisphosphate carboxylase/oxygenase (Rubisco) activity and quantity and net photosynthesis in greenhouse-grown Solanum tuberosum L. cv Norland foliage was studied in relation to oxidant-induced premature senescence. Plants, 26 days old, were exposed to 0.06 to 0.08 microliters per liter O{sub 3} from 1,000 to 1,600 hours for 4 days in a controlled environment chamber. On day 5, plants were exposed to a 6-hour simulated inversion in which O{sub 3} peaked at 0.12 microliters per liter. Net photosynthesis declined in response to O{sub 3} but recovered to near control levels 3 days after the exposure ended. Rubisco activity and quantity in control potato foliage increased and then decreased during the 12-day interval of the study. In some experiments foliage studied was physiologically mature and Rubisco activity had peaked when O{sub 3} exposure commenced. In those cases, O{sub 3} accelerated the decline in Rubisco activity. When less mature foliage was treated with O{sub 3}, the leaves never achieved the maximal level of Rubisco activity observed in control foliage and also exhibited more rapid decline in initial and total activity. Percent activation of Rubisco (initial/total activity) was not affected significantly by treatment. Quantity of Rubisco decreased in concert with activity. The reduction in the quantity of Rubisco, an important foliage storage protein, could contribute to premature senescence associated with toxicity of this air pollutant.

  3. Metabolic regulation of invadopodia and invasion by acetyl-CoA carboxylase 1 and de novo lipogenesis.

    Directory of Open Access Journals (Sweden)

    Kristen E N Scott

    Full Text Available Invadopodia are membrane protrusions that facilitate matrix degradation and cellular invasion. Although lipids have been implicated in several aspects of invadopodia formation, the contributions of de novo fatty acid synthesis and lipogenesis have not been defined. Inhibition of acetyl-CoA carboxylase 1 (ACC1, the committed step of fatty acid synthesis, reduced invadopodia formation in Src-transformed 3T3 (3T3-Src cells, and also decreased the ability to degrade gelatin. Inhibition of fatty acid synthesis through AMP-activated kinase (AMPK activation and ACC phosphorylation also decreased invadopodia incidence. The addition of exogenous 16∶0 and 18∶1 fatty acid, products of de novo fatty acid synthesis, restored invadopodia and gelatin degradation to cells with decreased ACC1 activity. Pharmacological inhibition of ACC also altered the phospholipid profile of 3T3-Src cells, with the majority of changes occurring in the phosphatidylcholine (PC species. Exogenous supplementation with the most abundant PC species, 34∶1 PC, restored invadopodia incidence, the ability to degrade gelatin and the ability to invade through matrigel to cells deficient in ACC1 activity. On the other hand, 30∶0 PC did not restore invadopodia and 36∶2 PC only restored invadopodia incidence and gelatin degradation, but not cellular invasion through matrigel. Pharmacological inhibition of ACC also reduced the ability of MDA-MB-231 breast, Snb19 glioblastoma, and PC-3 prostate cancer cells to invade through matrigel. Invasion of PC-3 cells through matrigel was also restored by 34∶1 PC supplementation. Collectively, the data elucidate the novel metabolic regulation of invadopodia and the invasive process by de novo fatty acid synthesis and lipogenesis.

  4. AMPK activation represses the human gene promoter of the cardiac isoform of acetyl-CoA carboxylase: Role of nuclear respiratory factor-1

    Energy Technology Data Exchange (ETDEWEB)

    Adam, Tasneem; Opie, Lionel H. [Hatter Cardiovascular Research Institute, Faculty of Health Sciences, University of Cape Town, Observatory 7925 (South Africa); Essop, M. Faadiel, E-mail: mfessop@sun.ac.za [Cardio-Metabolic Research Group (CMRG), Department of Physiological Sciences, Stellenbosch University, Stellenbosch 7600 (South Africa)

    2010-07-30

    Research highlights: {yields} AMPK inhibits acetyl-CoA carboxylase beta gene promoter activity. {yields} Nuclear respiratory factor-1 inhibits acetyl-CoA carboxylase beta promoter activity. {yields} AMPK regulates acetyl-CoA carboxylase beta at transcriptional level. -- Abstract: The cardiac-enriched isoform of acetyl-CoA carboxylase (ACC{beta}) produces malonyl-CoA, a potent inhibitor of carnitine palmitoyltransferase-1. AMPK inhibits ACC{beta} activity, lowering malonyl-CoA levels and promoting mitochondrial fatty acid {beta}-oxidation. Previously, AMPK increased promoter binding of nuclear respiratory factor-1 (NRF-1), a pivotal transcriptional modulator controlling gene expression of mitochondrial proteins. We therefore hypothesized that NRF-1 inhibits myocardial ACC{beta} promoter activity via AMPK activation. A human ACC{beta} promoter-luciferase construct was transiently transfected into neonatal cardiomyocytes {+-} a NRF-1 expression construct. NRF-1 overexpression decreased ACC{beta} gene promoter activity by 71 {+-} 4.6% (p < 0.001 vs. control). Transfections with 5'-end serial promoter deletions revealed that NRF-1-mediated repression of ACC{beta} was abolished with a pPII{beta}-18/+65-Luc deletion construct. AMPK activation dose-dependently reduced ACC{beta} promoter activity, while NRF-1 addition did not further decrease it. We also investigated NRF-1 inhibition in the presence of upstream stimulatory factor 1 (USF1), a known transactivator of the human ACC{beta} gene promoter. Here NRF-1 blunted USF1-dependent induction of ACC{beta} promoter activity by 58 {+-} 7.5% (p < 0.001 vs. control), reversed with a dominant negative NRF-1 construct. NRF-1 also suppressed endogenous USF1 transcriptional activity by 55 {+-} 6.2% (p < 0.001 vs. control). This study demonstrates that NRF-1 is a novel transcriptional inhibitor of the human ACC{beta} gene promoter in the mammalian heart. Our data extends AMPK regulation of ACC{beta} to the transcriptional level.

  5. Abundance and distribution of archaeal acetyl-CoA/propionyl-CoA carboxylase genes indicative for putatively chemoautotrophic Archaea in the tropical Atlantic's interior

    OpenAIRE

    Bergauer, Kristin; Sintes, Eva; van Bleijswijk, Judith; Witte, Harry; Herndl, Gerhard J.; Lueders, Tillmann

    2013-01-01

    Recently, evidence suggests that dark CO2 fixation in the pelagic realm of the ocean does not only occur in the suboxic and anoxic water bodies but also in the oxygenated meso- and bathypelagic waters of the North Atlantic. To elucidate the significance and phylogeny of the key organisms mediating dark CO2 fixation in the tropical Atlantic, we quantified functional genes indicative for CO2 fixation. We used a Q-PCR-based assay targeting the bifunctional acetyl-CoA/propionyl-CoA carboxylase (a...

  6. Protein phosphatases active on acetyl-CoA carboxylase phosphorylated by casein kinase I, casein kinase II and the cAMP-dependent protein kinase

    International Nuclear Information System (INIS)

    The protein phosphatases in rat liver cytosol, active on rat liver acetyl-CoA carboxylase (ACC) phosphorylated by casein kinase I, casein kinase II and the cAMP-dependent protein kinase, have been partially purified by anion-exchange and gel filtration chromatography. The major phosphatase activities against all three substrates copurify through fractionation and appear to be identical to protein phosphatases 2A1 and 2A2. No unique protein phosphatase active on 32P-ACC phosphorylated by the casein kinases was identified

  7. Mild water stress effects on carbon-reduction-cycle intermediates, ribulose bisphosphate carboxylase activity, and spatial homogeneity of photosynthesis in intact leaves

    International Nuclear Information System (INIS)

    We have examined the effect of mild water stress on photosynthetic chloroplast reactions of intact Phaseolus vulgaris leaves by measuring two parameters of ribulose bisphosphate (RuBP) carboxylase activity and the pool sizes of RuBP, 3-phosphoglycerate (PGA), triose phosphates, hexose monophosphates, and ATP. We also tested for patchy stomatal closure by feeding 14CO2. The kcat of RuBP carboxylase (moles CO2 fixed per mole enzyme per second) which could be measured after incubating the enzyme with CO2 and Mg2+ was unchanged by water stress. The ratio of activity before and after incubation with CO2 and Mg2+ (the carbamylation state) was slightly reduced by severe stress but not by mild stress. Likewise, the concentration of RuBP was slightly reduced by severe stress but not by mild stress. The concentration of PGA was markedly reduced by both mild and severe water stress. The concentration of triose phosphates did not decline as much as PGA. We found that photosynthesis in water stressed leaves occurred in patches. The patchiness of photosynthesis during water stress may lead to an underestimation of the effect of stomatal closure. We conclude that reductions in whole leaf photosynthesis caused by mild water stress are primarily the result of stomatal closure and that there is no indication of damage to chloroplast reactions

  8. Influence of the nitrate concentration and source in the incorporation of 14CO2 by the RuBP-carboxylase from wheat (triticum aestivum) and maize (zea mays)

    International Nuclear Information System (INIS)

    The effect of the concentration and source of nitrogen in the culture media has been studied regarding its influence in the activity of the RuBP-carboxylase from wheat and maize during the first month of development. Wheat and maize has been chosen as plants representatives of two different types of CO2 assimilation: C3 and M- respectively. Plants have been grown in hydroponic media and under temperature, humidity and nutrient salts control. A negative effect of NH4 has been observed in the enzymatic activity of wheat seedlings, being this effect more remarkable as NH4 concentration increases and as long the time of treatment. In our experimental conditions the most favorable source of nitrogen has been N03NH4. The specific activity of the enzyme from wheat is about four times higher than in maize, even it decreases with time. This decreasing has not been observed in maize, with the exception of total absence of nitrogen in the media. We have not seen significant differences between the two photo periods which have been tested. Also, no differences have been found in the enzyme activities at the different NO3NH4 concentrations assayed, and it seems that RuBP-carboxylase metabolism is only affected in the case of absolute stress. (Author) 20 refs

  9. Photoperiodism and crassulacean acid metabolism : I. Immunological and kinetic evidences for different patterns of phosphoenolpyruvate carboxylase isoforms in photoperiodically inducible and non-inducible Crassulacean acid metabolism plants.

    Science.gov (United States)

    Brulfert, J; Müller, D; Kluge, M; Queiroz, O

    1982-05-01

    Plants of Kalanchoe blossfeldiana v. Poelln. Tom Thumb and Sedum morganianum E. Walth. were grown under controlled photoperiodic conditions under either short or long days. Gaz exchange measurements confirmed that in K. blossfeldiana Crassulacean acid metabolism (CAM) was photoperiodically inducible and that S. morganianum performed CAM independently of photoperiod. With K. blossfeldiana, a comparison of catalytic and regulatory properties of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) from short-day and long-day grown plants showed differences, but not with S. morganianum. Ouchterlony double diffusion tests and immunotitration experiments (using a S. morganianum PEPC antibody) established that CAM is induced in K. blossfeldiana-but not in S. morganianum-through the synthesis of a new PEPC isoform; this form shows an immunological behavior different from that prevailing under non-inductive conditions and can be considered as specific for CAM performance. PMID:24276159

  10. Accumulation fatty acids of in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoA carboxylase, temperature, and co-immobilization with Azospirillum brasilense

    Science.gov (United States)

    Leyva, Luis A.; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E.

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.

  11. Genes encoding the alpha-carboxyltransferase subunit of acetyl-CoA carboxylase from Brassica napus and parental species: cloning, expression patterns, and evolution.

    Science.gov (United States)

    Li, Zhi-Guo; Yin, Wei-Bo; Guo, Huan; Song, Li-Ying; Chen, Yu-Hong; Guan, Rong-Zhan; Wang, Jing-Qiao; Wang, Richard R-C; Hu, Zan-Min

    2010-05-01

    Heteromeric acetyl coenzyme A carboxylase (ACCase), a rate-limiting enzyme in fatty acid biosynthesis in dicots, is a multi-enzyme complex consisting of biotin carboxylase, biotin carboxyl carrier protein, and carboxyltransferase (alpha-CT and beta-CT). In the present study, four genes encoding alpha-CT were cloned from Brassica napus, and two were cloned from each of the two parental species, B. rapa and B. oleracea. Comparative and cluster analyses indicated that these genes were divided into two major groups. The major divergence between group-1 and group-2 occurred in the second intron. Group-2 alpha-CT genes represented the ancestral form in the genus Brassica. The divergence of group-1 and group-2 genes occurred in their common ancestor 12.96-17.78 million years ago (MYA), soon after the divergence of Arabidopsis thaliana and Brassica (15-20 MYA). This time of divergence is identical to that reported for the paralogous subgenomes of diploid Brassica species (13-17 MYA). Real-time reverse transcription PCR revealed that the expression patterns of the two groups of genes were similar in different organs, except in leaves. To better understand the regulation and evolution of alpha-CT genes, promoter regions from two sets of orthologous gene copies from B. napus, B. rapa, and B. oleracea were cloned and compared. The function of the promoter of gene Bnalpha-CT-1-1 in group-1 and gene Bnalpha-CT-2-1 in group-2 was examined by assaying beta-glucuronidase activity in transgenic A. thaliana. Our results will be helpful in elucidating the evolution and regulation of ACCase in oilseed rape. PMID:20616867

  12. Cloning and Characterization of a Pyruvate Carboxylase Gene from Penicillium rubens and Overexpression of the Genein the Yeast Yarrowia lipolytica for Enhanced Citric Acid Production.

    Science.gov (United States)

    Fu, Ge-Yi; Lu, Yi; Chi, Zhe; Liu, Guang-Lei; Zhao, Shou-Feng; Jiang, Hong; Chi, Zhen-Ming

    2016-02-01

    In this study, a pyruvate carboxylase gene (PYC1) from a marine fungus Penicillium rubens I607 was cloned and characterized. ORF of the gene (accession number: KM397349.1) had 3534 bp encoding 1177 amino acids with a molecular weight of 127.531 kDa and a PI of 6.20. The promoter of the gene was located at -1200 bp and contained a TATAA box, several CAAT boxes and a sequence 5'-SYGGRG-3'. The PYC1 deduced from the gene had no signal peptide, was a homotetramer (α4), and had the four functional domains. After expression of the PYC1 gene from the marine fungus in the marine-derived yeast Yarrowia lipolytica SWJ-1b, the transformant PR32 obtained had much higher specific pyruvate carboxylase activity (0.53 U/mg) than Y. lipolytica SWJ-1b (0.07 U/mg), and the PYC1 gene expression (133.8%) and citric acid production (70.2 g/l) by the transformant PR32 were also greatly enhanced compared to those (100 % and 27.3 g/l) by Y. lipolytica SWJ-1b. When glucose concentration in the medium was 60.0 g/l, citric acid (CA) concentration formed by the transformant PR32 was 36.1 g/l, leading to conversion of 62.1% of glucose into CA. During a 10-l fed-batch fermentation, the final concentration of CA was 111.1 ± 1.3 g/l, the yield was 0.93 g/g, the productivity was 0.46 g/l/h, and only 1.72 g/l reducing sugar was left in the fermented medium within 240 h. HPLC analysis showed that most of the fermentation products were CA. However, minor malic acid and other unknown products also existed in the culture. PMID:26470708

  13. New insights into the post-translational modification of multiple phosphoenolpyruvate carboxylase isoenzymes by phosphorylation and monoubiquitination during sorghum seed development and germination.

    Science.gov (United States)

    Ruiz-Ballesta, Isabel; Baena, Guillermo; Gandullo, Jacinto; Wang, Liqun; She, Yi-Min; Plaxton, William Charles; Echevarría, Cristina

    2016-05-01

    Phosphoenolpyruvate carboxylase (PEPC; E.C. 4.1.1.31) was characterized in developing and germinating sorghum seeds, focusing on the transcript and polypeptide abundance of multiple plant-type phosphoenolpyruvate carboxylase (PTPC) genes, and the post-translational modification of each isoenzyme by phosphorylation versus monoubiquitination during germination. We observed high levels of SbPPC4 (Sb07g014960) transcripts during early development (stage I), and extensive transcript abundance of SbPPC2 (Sb02g021090) and SbPPC3 (Sb04g008720) throughout the entire life cycle of the seed. Although tandem mass spectrometry (MS) analysis of immunopurified PTPC indicated that four different PTPC isoenzymes were expressed in the developing and germinating seeds, SbPPC3 was the most abundant isozyme of the developing seed, and of the embryo and the aleurone layer of germinating seeds. In vivo phosphorylation of the different PTPC isoenzymes at their conserved N-terminal seryl phosphorylation site during germination was also established by MS/MS analysis. Furthermore, three of the four isoenzymes were partially monoubiquitinated, with MS/MS pinpointing SbPPC2 and SbPPC3 monoubiquitination at the conserved Lys-630 and Lys-624 residues, respectively. Our results demonstrate that monoubiquitination and phosphorylation simultaneously occur in vivo with different PTPC isozymes during seed germination. In addition, we show that PTPC monoubiquitination in germinating sorghum seeds always increases at stage II (emergence of the radicle), is maintained during the aerobic period of rapid cell division and reserve mobilization, and remains relatively constant until stage IV-V when coleoptiles initiate the formation of the photosynthetic tissues. PMID:27194739

  14. Increased expression of fatty acid synthase and acetyl-CoA carboxylase in the prefrontal cortex and cerebellum in the valproic acid model of autism

    Science.gov (United States)

    Chen, Jianling; Wu, Wei; Fu, Yingmei; Yu, Shunying; Cui, Donghong; Zhao, Min; Du, Yasong; Li, Jijun; Li, Xiaohong

    2016-01-01

    The primary aim of the present study was to investigate alterations in enzymes associated with fatty acid synthesis, namely fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC), in the prefrontal cortex and cerebellum of the valproic acid (VPA)-induced animal model of autism. In this model, pregnant rats were given a single intraperitoneal injection of VPA, and prefrontal cortex and cerebellum samples from their pups were analyzed. The results of western blotting and reverse transcription-quantitative polymerase chain reaction analyses demonstrated that the protein and mRNA expression levels of FASN, ACC and phospho-ACC (pACC) were increased in the prefrontal cortex and cerebellum of the VPA model of autism. Furthermore, in the prefrontal cortex and cerebellum of the VPA model of autism, AMPK expression is increased, whereas PI3K and Akt expression are unchanged. This suggests that disorder of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt/FASN and/or adenosine 5′-monophosphate-activated protein kinase (AMPK)/ACC pathway may be involved in the pathogenesis of autism. It is hypothesized that fatty acid synthesis participates in autism through PI3K/Akt/FASN and AMPK/ACC pathways. PMID:27602061

  15. The glossyhead1 Allele of ACC1 Reveals a Principal Role for Multidomain Acetyl-Coenzyme A Carboxylase in the Biosynthesis of Cuticular Waxes by Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Lu, S.; Xu, C.; Zhao, H.; Parsons, E. P.; Kosma, D. K.; Xu, X.; Chao, D.; Lohrey, G.; Bangarusamy, D. K.; Wang, G.; Bressan, R. A.; Jenks, M. A.

    2011-11-01

    A novel mutant of Arabidopsis (Arabidopsis thaliana), having highly glossy inflorescence stems, postgenital fusion in floral organs, and reduced fertility, was isolated from an ethyl methanesulfonate-mutagenized population and designated glossyhead1 (gsd1). The gsd1 locus was mapped to chromosome 1, and the causal gene was identified as a new allele of Acetyl-Coenzyme A Carboxylase1 (ACC1), a gene encoding the main enzyme in cytosolic malonyl-coenzyme A synthesis. This, to our knowledge, is the first mutant allele of ACC1 that does not cause lethality at the seed or early germination stage, allowing for the first time a detailed analysis of ACC1 function in mature tissues. Broad lipid profiling of mature gsd1 organs revealed a primary role for ACC1 in the biosynthesis of the very-long-chain fatty acids (C{sub 20:0} or longer) associated with cuticular waxes and triacylglycerols. Unexpectedly, transcriptome analysis revealed that gsd1 has limited impact on any lipid metabolic networks but instead has a large effect on environmental stress-responsive pathways, especially senescence and ethylene synthesis determinants, indicating a possible role for the cytosolic malonyl-coenzyme A-derived lipids in stress response signaling.

  16. Decreasing the Rate of Metabolic Ketone Reduction in the Discovery of a Clinical Acetyl-CoA Carboxylase Inhibitor for the Treatment of Diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, David A. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Kung, Daniel W. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Esler, William P. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Amor, Paul A. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Bagley, Scott W. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Beysen, Carine [KineMed Inc., Emeryville, CA (United States); Carvajal-Gonzalez, Santos [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Doran, Shawn D. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Limberakis, Chris [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Mathiowetz, Alan M. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); McPherson, Kirk [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Price, David A. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Ravussin, Eric [Louisiana State Univ., Baton Rouge, LA (United States); Sonnenberg, Gabriele E. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Southers, James A. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Sweet, Laurel J. [Pfizer Worldwide Research and Development, Cambridge, MA (United States); Turner, Scott M. [KineMed Inc., Emeryville, CA (United States); Vajdos, Felix F. [Pfizer Worldwide Research and Development, Cambridge, MA (United States)

    2014-12-26

    We found that Acetyl-CoA carboxylase (ACC) inhibitors offer significant potential for the treatment of type 2 diabetes mellitus (T2DM), hepatic steatosis, and cancer. However, the identification of tool compounds suitable to test the hypothesis in human trials has been challenging. An advanced series of spirocyclic ketone-containing ACC inhibitors recently reported by Pfizer were metabolized in vivo by ketone reduction, which complicated human pharmacology projections. Here, we disclose that this metabolic reduction can be greatly attenuated through introduction of steric hindrance adjacent to the ketone carbonyl. Incorporation of weakly basic functionality improved solubility and led to the identification of 9 as a clinical candidate for the treatment of T2DM. Phase I clinical studies demonstrated dose-proportional increases in exposure, single-dose inhibition of de novo lipogenesis (DNL), and changes in indirect calorimetry consistent with increased whole-body fatty acid oxidation. This demonstration of target engagement validates the use of compound 9 to evaluate the role of DNL in human disease.

  17. The glossyhead1 allele of acc1 reveals a principal role for multidomain acetyl-coenzyme a carboxylase in the biosynthesis of cuticular waxes by Arabidopsis

    KAUST Repository

    Lu, Shiyou

    2011-09-23

    A novel mutant of Arabidopsis (Arabidopsis thaliana), having highly glossy inflorescence stems, postgenital fusion in floral organs, and reduced fertility, was isolated from an ethyl methanesulfonate-mutagenized population and designated glossyhead1 (gsd1). The gsd1 locus was mapped to chromosome 1, and the causal gene was identified as a new allele of Acetyl-Coenzyme A Carboxylase1 (ACC1), a gene encoding the main enzyme in cytosolic malonyl-coenzyme A synthesis. This, to our knowledge, is the first mutant allele of ACC1 that does not cause lethality at the seed or early germination stage, allowing for the first time a detailed analysis of ACC1 function in mature tissues. Broad lipid profiling of mature gsd1 organs revealed a primary role for ACC1 in the biosynthesis of the very-long-chain fatty acids (C 20:0 or longer) associated with cuticular waxes and triacylglycerols. Unexpectedly, transcriptome analysis revealed that gsd1 has limited impact on any lipid metabolic networks but instead has a large effect on environmental stress-responsive pathways, especially senescence and ethylene synthesis determinants, indicating a possible role for the cytosolic malonyl-coenzyme A-derived lipids in stress response signaling. © 2011 American Society of Plant Biologists. All Rights Reserved.

  18. Biotin augments acetyl CoA carboxylase 2 gene expression in the hypothalamus, leading to the suppression of food intake in mice.

    Science.gov (United States)

    Sone, Hideyuki; Kamiyama, Shin; Higuchi, Mutsumi; Fujino, Kaho; Kubo, Shizuka; Miyazawa, Masami; Shirato, Saya; Hiroi, Yuka; Shiozawa, Kota

    2016-07-29

    It is known that biotin prevents the development of diabetes by increasing the functions of pancreatic beta-cells and improving insulin sensitivity in the periphery. However, its anti-obesity effects such as anorectic effects remain to be clarified. Acetyl CoA carboxylase (ACC), a biotin-dependent enzyme, has two isoforms (ACC1 and ACC2) and serves to catalyze the reaction of acetyl CoA to malonyl CoA. In the hypothalamus, ACC2 increases the production of malonyl CoA, which acts as a satiety signal. In this study, we investigated whether biotin increases the gene expression of ACC2 in the hypothalamus and suppresses food intake in mice administered excessive biotin. Food intake was significantly decreased by biotin, but plasma regulators of appetite, including glucose, ghrelin, and leptin, were not affected. On the other hand, biotin notably accumulated in the hypothalamus and enhanced ACC2 gene expression there, but it did not change the gene expression of ACC1, malonyl CoA decarboxylase (a malonyl CoA-degrading enzyme), and AMP-activated protein kinase α-2 (an ACC-inhibitory enzyme). These findings strongly suggest that biotin potentiates the suppression of appetite by upregulating ACC2 gene expression in the hypothalamus. This effect of biotin may contribute to the prevention of diabetes by biotin treatment. PMID:27181349

  19. Effect of CO{sub 2} concentration on carbonic anhydrase and ribulose-1,5-bisphosphate carboxylase/oxygenase expression in pea

    Energy Technology Data Exchange (ETDEWEB)

    Majeau, N.; Coleman, J.R. [Univ. of Toronto, Ontario (Canada)

    1996-10-01

    The effect of external CO{sub 2} concentration on the expression of carbonic anhydrase (CA) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was examined in pea (Pisum sativum cv Little Marvel) leaves. Enzyme activities and their transcript levels were reduced in plants grown at 1000 {mu}L/L CO{sub 2} compared with plants grown in ambient air. Growth at 160 {mu}L/L CO{sub 2} also appeared to reduce steady-state transcript levels for the rbcS, the gene encoding the small subunit of Rubisco, and for ca, the gene encoding CA; however, rbcS transcripts were reduced to a greater extent at this concentration. Rubisco activity was slightly lower in plants grown at 160 {mu}L/L CO{sub 2}, and CA activity was significantly higher than that observed in air-grown plants. Transfer of plants from 1000 {mu}L/L to air levels of CO{sub 2} resulted in a rapid increase in both ca and rbcS transcript abundance in fully expanded leaves, followed by an increase in enzyme activity. Plants transferred from air to high-CO{sub 2} concentrations appeared to modulate transcript abundance and enzyme activity less quickly. Foliar carbohydrate levels were also examined in plants grown continuously at high and ambient CO{sub 2}, and following changes in growth conditions that rapidly altered ca and rbcS transcript abundance and enzyme activities. 39 refs., 2 figs., 3 tabs.

  20. Search for novel targets of the PII signal transduction protein in Bacteria identifies the BCCP component of acetyl-CoA carboxylase as a PII binding partner.

    Science.gov (United States)

    Rodrigues, Thiago E; Gerhardt, Edileusa C M; Oliveira, Marco A; Chubatsu, Leda S; Pedrosa, Fabio O; Souza, Emanuel M; Souza, Gustavo A; Müller-Santos, Marcelo; Huergo, Luciano F

    2014-02-01

    The PII family comprises a group of widely distributed signal transduction proteins. The archetypal function of PII is to regulate nitrogen metabolism in bacteria. As PII can sense a range of metabolic signals, it has been suggested that the number of metabolic pathways regulated by PII may be much greater than described in the literature. In order to provide experimental evidence for this hypothesis a PII protein affinity column was used to identify PII targets in Azospirillum brasilense. One of the PII partners identified was the biotin carboxyl carrier protein (BCCP), a component of the acetyl-CoA carboxylase which catalyses the committed step in fatty acid biosynthesis. As BCCP had been previously identified as a PII target in Arabidopsis thaliana we hypothesized that the PII -BCCP interaction would be conserved throughout Bacteria. In vitro experiments using purified proteins confirmed that the PII -BCCP interaction is conserved in Escherichia coli. The BCCP-PII interaction required MgATP and was dissociated by increasing 2-oxoglutarate. The interaction was modestly affected by the post-translational uridylylation status of PII ; however, it was completely dependent on the post-translational biotinylation of BCCP. PMID:24329683

  1. Status of the substrate binding sites of ribulose bisphosphate carboxylase as determined with 2-C-carboxyarabinitol 1,5-bisphosphate

    International Nuclear Information System (INIS)

    The properties of the tight and specific binding of 2-C-carboxy-D-arabinitol 1,5-bisphosphate (CABP), which occurs only to reaction sites of ribulose 1,5-bisphosphate carboxylase (Rubisco) that are activated by CO2 and Mg2+, were studied. With fully active purified spinach (Spinacia oleracea) Rubisco the rate of tight binding of [14C]CABP fit a multiple exponential rate equation with half of the sites binding with a rate constant of 40 per minute and the second half of the sites binding at 3.2 per minute. This suggests that after CABP binds to one site of a dimer of Rubisco large subunits, binding to the second site is considerably slower, indicating negative cooperativity as previously reported. The rate of CABP binding to partially activated Rubisco was complete within 2 to 5 minutes, with slower binding to inactive sites as they formed the carbamate and bound Mg2+. Addition of [14C]CABP and EDTA stopped binding of Mg2+ and allowed tight binding of the radiolabel only to sites which were CO2/Mg2+-activated at that moment. The rate of CO2 fixation was proportional to the CO2/Mg2+-activated sites. During light-dependent CO2 fixation with isolated spinach chloroplasts, the amount of carbamylation was proportional to Rubisco activity either initially upon lysis of the plastids or following total activation with Mg2+ and CO2. Lysis of chloroplasts in media with [14C]CABP plus EDTA estimated those carbamylated sites having Mg2+. The loss of Rubisco activation during illumination was partially due to the lack of Mg2+ to stabilize the carbamylated sites

  2. Inhibition of acetyl-CoA carboxylases by soraphen A prevents lipid accumulation and adipocyte differentiation in 3T3-L1 cells.

    Science.gov (United States)

    Cordonier, Elizabeth L; Jarecke, Sarah K; Hollinger, Frances E; Zempleni, Janos

    2016-06-01

    Acetyl-CoA carboxylases (ACC) 1 and 2 catalyze the carboxylation of acetyl-CoA to malonyl-CoA and depend on biotin as a coenzyme. ACC1 localizes in the cytoplasm and produces malonyl-CoA for fatty acid (FA) synthesis. ACC2 localizes in the outer mitochondrial membrane and produces malonyl-CoA that inhibits FA import into mitochondria for subsequent oxidation. We hypothesized that ACCs are checkpoints in adipocyte differentiation and tested this hypothesis using the ACC1 and ACC2 inhibitor soraphen A (SA) in murine 3T3-L1 preadipocytes. When 3T3-L1 cells were treated with 100nM SA for 8 days after induction of differentiation, the expression of PPARγ mRNA and FABP4 mRNA decreased by 40% and 50%, respectively, compared with solvent controls; the decrease in gene expression was accompanied by a decrease in FABP4 protein expression and associated with a decrease in lipid droplet accumulation. The rate of FA oxidation was 300% greater in SA-treated cells compared with vehicle controls. Treatment with exogenous palmitate restored PPARγ and FABP4 mRNA expression and FABP4 protein expression in SA-treated cells. In contrast, SA did not alter lipid accumulation if treatment was initiated on day eight after induction of differentiation. We conclude that loss of ACC1-dependent FA synthesis and loss of ACC2-dependent inhibition of FA oxidation prevent lipid accumulation in adipocytes and inhibit early stages of adipocyte differentiation. PMID:27041646

  3. Discrimination in the dark. Resolving the interplay between metabolic and physical constraints to phosphoenolpyruvate carboxylase activity during the crassulacean acid metabolism cycle.

    Science.gov (United States)

    Griffiths, Howard; Cousins, Asaph B; Badger, Murray R; von Caemmerer, Susanne

    2007-02-01

    A model defining carbon isotope discrimination (delta13C) for crassulacean acid metabolism (CAM) plants was experimentally validated using Kalanchoe daigremontiana. Simultaneous measurements of gas exchange and instantaneous CO2 discrimination (for 13C and 18O) were made from late photoperiod (phase IV of CAM), throughout the dark period (phase I), and into the light (phase II). Measurements of CO2 response curves throughout the dark period revealed changing phosphoenolpyruvate carboxylase (PEPC) capacity. These systematic changes in PEPC capacity were tracked by net CO2 uptake, stomatal conductance, and online delta13C signal; all declined at the start of the dark period, then increased to a maximum 2 h before dawn. Measurements of delta13C were higher than predicted from the ratio of intercellular to external CO2 (p(i)/p(a)) and fractionation associated with CO2 hydration and PEPC carboxylations alone, such that the dark period mesophyll conductance, g(i), was 0.044 mol m(-2) s(-1) bar(-1). A higher estimate of g(i) (0.085 mol m(-2) s(-1) bar(-1)) was needed to account for the modeled and measured delta18O discrimination throughout the dark period. The differences in estimates of g(i) from the two isotope measurements, and an offset of -5.5 per thousand between the 18O content of source and transpired water, suggest spatial variations in either CO2 diffusion path length and/or carbonic anhydrase activity, either within individual cells or across a succulent leaf. Our measurements support the model predictions to show that internal CO2 diffusion limitations within CAM leaves increase delta13C discrimination during nighttime CO2 fixation while reducing delta13C during phase IV. When evaluating the phylogenetic distribution of CAM, carbon isotope composition will reflect these diffusive limitations as well as relative contributions from C3 and C4 biochemistry. PMID:17142488

  4. Computational simulations of structural role of the active-site W374C mutation of acetyl-coenzyme-A carboxylase: multi-drug resistance mechanism.

    Science.gov (United States)

    Zhu, Xiao-Lei; Yang, Wen-Chao; Yu, Ning-Xi; Yang, Sheng-Gang; Yang, Guang-Fu

    2011-03-01

    Herbicides targeting grass plastidic acetyl-CoA carboxylase (ACCase, EC 6.4.1.2) are selectively effective against graminicides. The intensive worldwide use of this herbicide family has selected for resistance genes in a number of grass weed species. Recently, the active-site W374C mutation was found to confer multi-drug resistance toward haloxyfop (HF), fenoxaprop (FR), Diclofop (DF), and clodinafop (CF) in A. myosuroides. In order to uncover the resistance mechanism due to W374C mutation, the binding of above-mentioned four herbicides to both wild-type and the mutant-type ACCase was investigated in the current work by molecular docking and molecular dynamics (MD) simulations. The binding free energies were calculated by molecular mechanics-Poisson-Boltzmann surface area (MM/PBSA) method. The calculated binding free energy values for four herbicides were qualitatively consistent with the experimental order of IC(50) values. All the computational model and energetic results indicated that the W374C mutation has great effects on the conformational change of the binding pocket and the ligand-protein interactions. The most significant conformational change was found to be associated with the aromatic amino acid residues, such as Phe377, Tyr161' and Trp346. As a result, the π-π interaction between the ligand and the residue of Phe377 and Tyr161', which make important contributions to the binding affinity, was decreased after mutation and the binding affinity for the inhibitors to the mutant-type ACCase was less than that to the wild-type enzyme, which accounts for the molecular basis of herbicidal resistance. The structural role and mechanistic insights obtained from computational simulations will provide a new starting point for the rational design of novel inhibitors to overcome drug resistance associated with W374C mutation. PMID:20499260

  5. Expression and methylation of microsomal triglyceride transfer protein and acetyl-CoA carboxylase are associated with fatty liver syndrome in chicken.

    Science.gov (United States)

    Liu, Zhen; Li, Qinghe; Liu, Ranran; Zhao, Guiping; Zhang, Yonghong; Zheng, Maiqing; Cui, Huanxian; Li, Peng; Cui, Xiaoyan; Liu, Jie; Wen, Jie

    2016-06-01

    The typical characteristic of fatty liver syndrome (FLS) is an increased hepatic triacylglycerol content, and a sudden decline in egg production often occurs. FLS may develop into fatty liver hemorrhagic syndrome (FLHS), characterized by sudden death from hepatic rupture and hemorrhage. DNA methylation is associated with transcriptional silencing, leading to the etiology and pathogenesis of some animal diseases. The roles of DNA methylation in the genesis of FLS, however, are largely unknown. The lipogenic methyl-deficient diet (MDD) caused FLS similar to human nonalcoholic steatohepatitis (NASH). After 16 Jingxing-Huang (JXH) hens were fed MDD for 10 wk, eight exhibited FLS (designated as FLS-susceptible birds); the remainder, without FLS, served as controls (NFLS). Physiological and biochemical variables, gene expression levels, and DNA methylation were determined in the liver. The development of FLS in JXH hens was accompanied by abnormal lipid accumulation. Relative expression of acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and microsomal triglyceride transfer protein (MTTP) were significantly up-regulated in the FLS group in comparison with the NFLS group. The transcript abundance of sterol regulatory element binding protein 1 (SREBP-1c), stearoyl-CoA desaturase (SCD), liver X receptor alpha (LXRα), peroxisome proliferator-activated receptor alpha (PPARα), and peroxisome proliferator-activated receptor gamma (PPARγ) did not differ between the two groups. Interestingly, MTTP and ACC mRNA abundance were negatively correlated with the level of promoter methylation. The extent of DNA methylation of the cytosine-guanine (CpG) sites in the SREBP-1c, FAS, PPARα, and LXRα promoter regions was also analyzed by direct sequencing but none differed between FLS and NFLS birds. Taken together, these results specify link DNA methylation to the pathogenesis of FLS in chickens. PMID:27083546

  6. Recombinant thermoactive phosphoenolpyruvate carboxylase (PEPC) from Thermosynechococcus elongatus and its coupling with mesophilic/thermophilic bacterial carbonic anhydrases (CAs) for the conversion of CO2 to oxaloacetate.

    Science.gov (United States)

    Del Prete, Sonia; De Luca, Viviana; Capasso, Clemente; Supuran, Claudiu T; Carginale, Vincenzo

    2016-01-15

    With the continuous increase of atmospheric CO2 in the last decades, efficient methods for carbon capture, sequestration, and utilization are urgently required. The possibility of converting CO2 into useful chemicals could be a good strategy to both decreasing the CO2 concentration and for achieving an efficient exploitation of this cheap carbon source. Recently, several single- and multi-enzyme systems for the catalytic conversion of CO2 mainly to bicarbonate have been implemented. In order to design and construct a catalytic system for the conversion of CO2 to organic molecules, we implemented an in vitro multienzyme system using mesophilic and thermophilic enzymes. The system, in fact, was constituted by a recombinant phosphoenolpyruvate carboxylase (PEPC) from the thermophilic cyanobacterium Thermosynechococcus elongatus, in combination with mesophilic/thermophilic bacterial carbonic anhydrases (CAs), for converting CO2 into oxaloacetate, a compound of potential utility in industrial processes. The catalytic procedure is in two steps: the conversion of CO2 into bicarbonate by CA, followed by the carboxylation of phosphoenolpyruvate with bicarbonate, catalyzed by PEPC, with formation of oxaloacetate (OAA). All tested CAs, belonging to α-, β-, and γ-CA classes, were able to increase OAA production compared to procedures when only PEPC was used. Interestingly, the efficiency of the CAs tested in OAA production was in good agreement with the kinetic parameters for the CO2 hydration reaction of these enzymes. This PEPC also revealed to be thermoactive and thermostable, and when coupled with the extremely thermostable CA from Sulphurhydrogenibium azorense (SazCA) the production of OAA was achieved even if the two enzymes were exposed to temperatures up to 60 °C, suggesting a possible role of the two coupled enzymes in biotechnological processes. PMID:26712095

  7. Associations of polymorphisms in the promoter I of bovine acetyl-CoA carboxylase-alpha gene with beef fatty acid composition.

    Science.gov (United States)

    Zhang, S; Knight, T J; Reecy, J M; Wheeler, T L; Shackelford, S D; Cundiff, L V; Beitz, D C

    2010-08-01

    The objectives of this study were to identify single nucleotide polymorphisms (SNPs) in the promoter I (PI) region of the bovine acetyl-CoA carboxylase-alpha (ACACA) gene and to evaluate the extent to which they were associated with lipid-related traits. Eight novel SNPs were identified, which were AJ276223:g.2064T>A (SNP1), g.2155C>T (SNP2), g.2203G>T (SNP3), g.2268T>C (SNP4), g.2274G>A (SNP5), g.2340A>G (SNP6), g.2350T>C (SNP7) and g.2370A>G (SNP8). Complete linkage disequilibrium was observed among SNP1, 2, 4, 5, 6 and 8. Phenotypic data were collected from 573 cross-bred steers with six sire breeds, including Hereford, Angus, Brangus, Beefmaster, Bonsmara and Romosinuano. The genotypes of SNP1/2/4/5/6/8 were significantly associated with adjusted backfat thickness. The genotypes of SNP3 were significantly associated with triacylglycerol (TAG) content and fatty acid composition of longissimus dorsi muscle (LM) in Brangus-, Romosinuano- and Bonsmara-sired cattle. Cattle with g.2203GG genotype had greater concentrations of TAG, total lipid, total saturated fatty acid and total monounsaturated fatty acid than did cattle with g.2203GT genotype. The genotypes of SNP7 were significantly associated with fatty acid composition of LM. Cattle with genotype g.2350TC had greater amounts of several fatty acids in LM than did cattle with genotype g.2350CC. Our results suggested that the SNPs in the PI region of ACACA gene are associated with variations in the fatty acid contents in LM. PMID:20002363

  8. Pyruvate Carboxylase Is Up-Regulated in Breast Cancer and Essential to Support Growth and Invasion of MDA-MB-231 Cells.

    Directory of Open Access Journals (Sweden)

    Phatchariya Phannasil

    Full Text Available Pyruvate carboxylase (PC is an anaplerotic enzyme that catalyzes the carboxylation of pyruvate to oxaloacetate, which is crucial for replenishing tricarboxylic acid cycle intermediates when they are used for biosynthetic purposes. We examined the expression of PC by immunohistochemistry of paraffin-embedded breast tissue sections of 57 breast cancer patients with different stages of cancer progression. PC was expressed in the cancerous areas of breast tissue at higher levels than in the non-cancerous areas. We also found statistical association between the levels of PC expression and tumor size and tumor stage (P < 0.05. The involvement of PC with these two parameters was further studied in four breast cancer cell lines with different metastatic potentials; i.e., MCF-7, SKBR3 (low metastasis, MDA-MB-435 (moderate metastasis and MDA-MB-231 (high metastasis. The abundance of both PC mRNA and protein in MDA-MB-231 and MDA-MB-435 cells was 2-3-fold higher than that in MCF-7 and SKBR3 cells. siRNA-mediated knockdown of PC expression in MDA-MB-231 and MDA-MB-435 cells resulted in a 50% reduction of cell proliferation, migration and in vitro invasion ability, under both glutamine-dependent and glutamine-depleted conditions. Overexpression of PC in MCF-7 cells resulted in a 2-fold increase in their proliferation rate, migration and invasion abilities. Taken together the above results suggest that anaplerosis via PC is important for breast cancer cells to support their growth and motility.

  9. Characterization of ribulose-1, 5-bisphosphate carboxylase/oxygenase and transcriptional analysis of its related genes in Saccharina japonica (Laminariales, Phaeophyta)

    Science.gov (United States)

    Shao, Zhanru; Liu, Fuli; Li, Qiuying; Yao, Jianting; Duan, Delin

    2014-03-01

    Saccharina japonica is a common macroalga in sublittoral communities of cold seawater environments, and consequently may have highly efficient ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) activity for carbon assimilation. In our study, we cloned the full-length Rubisco gene from S. japonica ( SJ-rbc). It contained an open reading frame for a large subunit gene ( SJ — rbcL) of 1 467 bp, a small subunit gene ( SJ-rbcS) of 420 bp, and a SJ-rbcL/S intergenic spacer of 269 bp. The deduced peptides of SJ-rbcL and SJ-rbcS were 488 and 139 amino acids with theoretical molecular weights and isoelectric points of 53.97 kDa, 5.81 and 15.84 kDa, 4.71, respectively. After induction with 1 mmol/L isopropyl- β-D-thiogalactopyranoside for 5 h and purification by Ni2+ affinity chromatography, electrophoresis and western blot detection demonstrated successful expression of the 55 kDa SJ-rbcL protein. Real-time quantitative PCR showed that the mRNA levels of SJ-rbcL in gametophytes increased when transferred into normal growth conditions and exhibited diurnal variations: increased expression during the day but suppressed expression at night. This observation implied that Rubisco played a role in normal gametophytic growth and development. In juvenile sporophytes, mRNA levels of SJ-rbcL, carbonic anhydrase, Calvin-Benson-Bassham cycle-related enzyme, and chloroplast light-harvesting protein were remarkably increased under continuous light irradiance. Similarly, expression of these genes was up-regulated under blue light irradiance at 350 μmol/(m2·s). Our results indicate that long-term white light and short-term blue light irradiance enhances juvenile sporophytic growth by synergistic effects of various photosynthetic elements.

  10. Characterization of acetyl-CoA and propionyl-CoA carboxylases encoded by Leptospira interrogans serovar Lai: an initial biochemical study for leptospiral gluconeogenesis via anaplerotic CO2 assimilation

    Institute of Scientific and Technical Information of China (English)

    Nanqiu Peng; Yi Zhong; Qing Zhang; Mingyue Zheng; Wei Zhao; Hualiang Jiang; Chen Yang; Xiaokui Guo; Guoping Zhao

    2012-01-01

    Leptospira interrogans is the causative agent of leptospirosis.The in vitro growth of L.interrogans requires CO2 and a partial 3-hydroxypropionate pathway involving two acyl-CoA carboxylases was suggested by genomic analysis to assimilate CO2.Either set of the candidate genes heterologously co-expressed in Escherichia coli was able to demonstrate both acetyl-CoA carboxylase (ACC)and propionyl-CoA carboxylase (PCC) activities.The trisubunit holoenzyme (LA_2736-LA_2735 and LA_3803),although failed to be purified,was designated ACC based on its substrate preference toward acetyl-CoA.The partially purified bi-subunit holoenzyme (LA_2432-LA_2433) has a considerably higher activity against propionyi-CoA as the substrate than that of acetyl-CoA,and thus,designated PCC.Native polyacrylamide gel electrophoresis indicated that this PCC has a molecular mass of around 669 kDa,suggesting an α4β4 quaternary structure and both structural homology modeling and site-directed mutagenesis analysis of its carboxyltransferase subunit (LA_2433) indicated that the A431 residue located at the bottom of the putative substrate binding pocket may play an important role in substrate specificity determination.Both transcriptomic and proteomic data indicated that enzymes involved in the suggested partial 3-hydroxypropionate pathway were expressed in vivo in addition to ACC/PCC and the homologous genes in genomes of other Leptospira species were re-annotated accordingly.However,as the in vitro detected specific activity of ACC in the crude cell extract was too low to account for the growth of the bacterium in Ellinghausen-McCulloughJohnson-Harris minimal medium,further systematic analysis is required to unveil the mechanism of gluconeogenesis via anaplerotic CO2 assimilation in Leptospira species.

  11. Effects of Light and Elevated Atmospheric CO(2) on the Ribulose Bisphosphate Carboxylase Activity and Ribulose Bisphosphate Level of Soybean Leaves.

    Science.gov (United States)

    Vu, C V; Allen, L H; Bowes, G

    1983-11-01

    Soybean (Glycine max L. Merr. cv Bragg) was grown throughout its life cycle at 330, 450, and 800 microliters CO(2) per liter in outdoor controlled-environment chambers under solar irradiance. Leaf ribulose-1,5-bisphosphate carboxylase (RuBPCase) activities and ribulose-1,5-bisphosphate (RuBP) levels were measured at selected times after planting. Growth under the high CO(2) levels reduced the extractable RuBPCase activity by up to 22%, but increased the daytime RuBP levels by up to 20%.Diurnal measurements of RuBPCase (expressed in micromoles CO(2) per milligram chlorophyll per hour) showed that the enzyme values were low (230) when sampled before sunrise, even when activated in vitro with saturating HCO(3) (-) and Mg(2+), but increased to 590 during the day as the solar quantum irradiance (photosynthetically active radiation or PAR, in micromoles per square meter per second) rose to 600. The nonactivated RuBPCase values, which averaged 20% lower than the corresponding HCO(3) (-) and Mg(2+)-activated values, increased in a similar manner with increasing solar PAR. The per cent RuBPCase activation (the ratio of nonactivated to maximum-activated values) increased from 40% before dawn to 80% during the day. Leaf RuBP levels (expressed in nanomoles per milligram chlorophyll) were close to zero before sunrise but increased to a maximum of 220 as the solar PAR rose beyond 1200. In a chamber kept dark throughout the morning, leaf RuBPCase activities and RuBP levels remained at the predawn values. Upon removal of the cover at noon, the HCO(3) (-) and Mg(2+)-activated RuBPCase values and the RuBP levels rose to 465 and 122, respectively, after only 5 minutes of leaf exposure to solar PAR at 1500.These results indicate that, in soybean leaves, light may exert a regulatory effect on extractable RuBPCase in addition to the well-established activation by CO(2) and Mg(2+). PMID:16663291

  12. The bacterial signal transduction protein GlnB regulates the committed step in fatty acid biosynthesis by acting as a dissociable regulatory subunit of acetyl-CoA carboxylase.

    Science.gov (United States)

    Gerhardt, Edileusa C M; Rodrigues, Thiago E; Müller-Santos, Marcelo; Pedrosa, Fabio O; Souza, Emanuel M; Forchhammer, Karl; Huergo, Luciano F

    2015-03-01

    Biosynthesis of fatty acids is one of the most fundamental biochemical pathways in nature. In bacteria and plant chloroplasts, the committed and rate-limiting step in fatty acid biosynthesis is catalyzed by a multi-subunit form of the acetyl-CoA carboxylase enzyme (ACC). This enzyme carboxylates acetyl-CoA to produce malonyl-CoA, which in turn acts as the building block for fatty acid elongation. In Escherichia coli, ACC is comprised of three functional modules: the biotin carboxylase (BC), the biotin carboxyl carrier protein (BCCP) and the carboxyl transferase (CT). Previous data showed that both bacterial and plant BCCP interact with signal transduction proteins belonging to the PII family. Here we show that the GlnB paralogues of the PII proteins from E. coli and Azospirillum brasiliense, but not the GlnK paralogues, can specifically form a ternary complex with the BC-BCCP components of ACC. This interaction results in ACC inhibition by decreasing the enzyme turnover number. Both the BC-BCCP-GlnB interaction and ACC inhibition were relieved by 2-oxoglutarate and by GlnB uridylylation. We propose that the GlnB protein acts as a 2-oxoglutarate-sensitive dissociable regulatory subunit of ACC in Bacteria. PMID:25557370

  13. Photocontrol of the expression of genes encoding chlorophyll a/b binding proteins and small subunit of ribulose-1,5-bisphosphate carboxylase in etiolated seedlings of Lycopersicon esculentum (L. ) and Nicotiana tabacum (L. )

    Energy Technology Data Exchange (ETDEWEB)

    Wehmeyer, B. (Univ. of Pennsylvania, Philadelphia (USA) Albert-Ludwigs-Universitaet, Freiburg (West Germany)); Cashmore, A.R. (Univ. of Pennsylvania, Philadelphia (USA)); Schaefer, E. (Albert-Ludwigs-Universitaet, Freiburg (West Germany))

    1990-07-01

    Phytochrome and the blue ultraviolet-A photoreceptor control light-induced expression of genes encoding the chlorophyll a/b binding protein of photosystem II and photosystem I and the genes for the small subunit of the ribulose-1,5-bisphosphate carboxylase in etiolated seedlings of Lycopersicon esculentum (tomato) and Nicotiana tabacum (tobacco). A high irradiance response also controls the induction of these genes. Genes encoding photosystem II- and I-associated chlorophyll a/b binding proteins both exhibit a transient rapid increase in expression in response to light pulse or to continuous irradiation. In contrast, genes encoding the small subunit exhibit a continuous increase in expression in response to light. These distinct expression characteristics are shown to reflect differences at the level of transcription.

  14. Design of small molecule inhibitors of acetyl-CoA carboxylase 1 and 2 showing reduction of hepatic malonyl-CoA levels in vivo in obese Zucker rats.

    Science.gov (United States)

    Bengtsson, Christoffer; Blaho, Stefan; Saitton, David Blomberg; Brickmann, Kay; Broddefalk, Johan; Davidsson, Ojvind; Drmota, Tomas; Folmer, Rutger; Hallberg, Kenth; Hallén, Stefan; Hovland, Ragnar; Isin, Emre; Johannesson, Petra; Kull, Bengt; Larsson, Lars-Olof; Löfgren, Lars; Nilsson, Kristina E; Noeske, Tobias; Oakes, Nick; Plowright, Alleyn T; Schnecke, Volker; Ståhlberg, Pernilla; Sörme, Pernilla; Wan, Hong; Wellner, Eric; Oster, Linda

    2011-05-15

    Inhibition of acetyl-CoA carboxylases has the potential for modulating long chain fatty acid biosynthesis and mitochondrial fatty acid oxidation. Hybridization of weak inhibitors of ACC2 provided a novel, moderately potent but lipophilic series. Optimization led to compounds 33 and 37, which exhibit potent inhibition of human ACC2, 10-fold selectivity over inhibition of human ACC1, good physical and in vitro ADME properties and good bioavailability. X-ray crystallography has shown this series binding in the CT-domain of ACC2 and revealed two key hydrogen bonding interactions. Both 33 and 37 lower levels of hepatic malonyl-CoA in vivo in obese Zucker rats. PMID:21515056

  15. Phytochrome control of gene expression in radish seedlings. II Far-red light mediated appearance of the ribulose 1,5-bisphosphate carboxylase and the mRNA for its small subunit

    International Nuclear Information System (INIS)

    The effect of far-red light on the appearance of the radish ribulose 1,5-bisphosphate carboxylase, its subunits and the mRNA for the small subunit has been studied. The immunological analysis of the accumulation of holoenzyme and small subunit showed that there was no pool of free small subunit either in the etiolated seedlings or in the far-red light illuminated seedlings. The precursor to the small subunit has been identified by immunoprecipitation of the in vitro translation products directed by poly(A)-containing RNA of radish cotyledons. The irradiation of radish cotyledons with far-red light led to the apparent increase of the level of the translatable mRNA for the small subunit. (author)

  16. Study of the properties of Ribulose 1,5-biphosphate carboxylase/oxygenase from maize (Zea mays) and wheat (Triticum aestivum) by incorporation of CO2 marking 14C

    International Nuclear Information System (INIS)

    After a bibliografic review of the properties of RuBP-carboxylase/oxygenase, a methodology is described which allows the treatment of a large number of samples for the assay of the enzyme activity. 14CO3HNa is used as a marker for the counting of the incorporated radioactivity as acid insoluble material. 14''CC2 from the labeled sodium bicarbonate is the species used by the enzyme both as an activator as well as a substrate. The following experiments are described and its results given: Determination of the optimal conditions for the activation of the enzyme; study of the kinetics of the catalytic action; effect of the Mg2 concentration and determination of the Km(s) from CO2 and ribulose 1,5-biphosphate; also determination of the optimum pH at different concentrations of CO22 and Mg2. (Author) 64 refs

  17. Determining Photosynthetic Parameters from Leaf CO2 Exchange and Chlorophyll Fluorescence (Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Specificity Factor, Dark Respiration in the Light, Excitation Distribution between Photosystems, Alternative Electron Transport Rate, and Mesophyll Diffusion Resistance.

    Science.gov (United States)

    Laisk, A.; Loreto, F.

    1996-03-01

    Using simultaneous measurements of leaf gas exchange and chlorophyll fluorescence, we determined the excitation partitioning to photosystem II (PSII), the CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase, the dark respiration in the light, and the alternative electron transport rate to acceptors other than bisphosphoglycerate, and the transport resistance for CO2 in the mesophyll cells for individual leaves of herbaceous and tree species. The specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase for CO2 was determined from the slope of the O2 dependence of the CO2 compensation point between 1.5 and 21% O2. Its value, on the basis of dissolved CO2 and O2 concentrations at 25.5[deg]C, varied between 86 and 89. Dark respiration in the light, estimated from the difference between the CO2 compensation point and the CO2 photocompensation point, was about 20 to 50% of the respiration rate in the dark. The excitation distribution to PSII was estimated from the extrapolation of the dependence of the PSII quantum yield on F/Fm to F = 0, where F is steady-state and Fm is pulse-satuarated fluorescence, and varied between 0.45 and 0.6. The alternative electron transport rate was found as the difference between the electron transport rates calculated from fluorescence and from gas exchange, and at low CO2 concentrations and 10 to 21% O2, it was 25 to 30% of the maximum electron transport. The calculated mesophyll diffusion resistance accounted for about 20 to 30% of the total mesophyll resistance, which also includes carboxylation resistance. Whole-leaf photosynthesis is limited by gas phase, mesophyll diffusion, and carboxylation resistances in nearly the same proportion in both herbaceous species and trees. PMID:12226229

  18. 杜氏盐藻磷酸烯醇式丙酮酸羧化酶基因的克隆和分析%Cloning and analysis of phosphoenolpyruvate carboxylase (PEPC) gene of Dunaliella salina

    Institute of Scientific and Technical Information of China (English)

    张楠楠; 潘卫东; 崔玉琳; 秦松; 薛乐勋

    2011-01-01

    为研究杜氏盐藻(Dunaliella salina)磷酸烯醇式丙酮酸羧化酶(phosphoenolpyruvate carboxylase,PEPC)基因的功能, 根据莱茵衣藻(Chlamydomonas reinhardtii)、拟南芥(Arabidopsis thaliana)、花生(Arachis hypogaea)等真核生物PEPC 基因高度保守序列, 设计一对简并引物, 通过RT-PCR 的方法获得杜氏盐藻PEPC 基因部分序列, 然后采用RACE 的方法分别克隆到5′端和3′端序列, 拼接后得到全长cDNA, 其长度为3 523bp, 包含2 949 bp 的完整开放阅读框, 编码982 个氨基酸, 相对分子质量为110560.5。氨基酸序列与已知物种PEPC 序列的同源性依次为: Chlamydomonas reinhardtii 69%, Chlorellavariabilis 55%, Ostreococcus tauri 50%和Ostreococcus lucimarinus CCE9901 49%, 表明所克隆的序列确为杜氏盐藻PEPC cDNA 序列。%To investigate the function of phosphoenolpyruvate carboxylase (PEPC) gene of Dunaliella salina, a pair of degenerate primers was designed according to the conserved motifs of the PEPC of Chlamydomonas reinhardtii, Arabidopsis thaliana, and Arachis hypogaea. A cDNA fragment was obtained from green alga Dunaliella salina through RT-PCR, and then the full length of the cDNA was isolated by 3’ and 5’RACE. The isolated cDNA sequence was 3523 bp in length with a 2949 bp coding region that encoded 982 amino acid residues with the predicted relative molecular mass of 110560.5 dolton. In addition, homology analysis showed that PEPC of D. salina was highly similar to that of C. reinhardtii(69%), Chlorella variabilis(55%), Ostreococcus tauri(50%), and O. lucimarinus CCE9901(49%), suggesting that the cDNA isolated from Dunaliella salina was PEPC-encoding.

  19. Serine 363 of a Hydrophobic Region of Archaeal Ribulose 1,5-Bisphosphate Carboxylase/Oxygenase from Archaeoglobus fulgidus and Thermococcus kodakaraensis Affects CO2/O2 Substrate Specificity and Oxygen Sensitivity.

    Directory of Open Access Journals (Sweden)

    Nathan E Kreel

    Full Text Available Archaeal ribulose 1, 5-bisphospate carboxylase/oxygenase (RubisCO is differentiated from other RubisCO enzymes and is classified as a form III enzyme, as opposed to the form I and form II RubisCOs typical of chemoautotrophic bacteria and prokaryotic and eukaryotic phototrophs. The form III enzyme from archaea is particularly interesting as several of these proteins exhibit unusual and reversible sensitivity to molecular oxygen, including the enzyme from Archaeoglobus fulgidus. Previous studies with A. fulgidus RbcL2 had shown the importance of Met-295 in oxygen sensitivity and pointed towards the potential significance of another residue (Ser-363 found in a hydrophobic pocket that is conserved in all RubisCO proteins. In the current study, further structure/function studies have been performed focusing on Ser-363 of A. fulgidus RbcL2; various changes in this and other residues of the hydrophobic pocket point to and definitively establish the importance of Ser-363 with respect to interactions with oxygen. In addition, previous findings had indicated discrepant CO2/O2 specificity determinations of the Thermococcus kodakaraensis RubisCO, a close homolog of A. fulgidus RbcL2. It is shown here that the T. kodakaraensis enzyme exhibits a similar substrate specificity as the A. fulgidus enzyme and is also oxygen sensitive, with equivalent residues involved in oxygen interactions.

  20. Plant, cell, and molecular mechanisms of abscisic-acid regulation of stomatal apertures. In vivo phosphorylation of phosphoenolpyruvate carboxylase in guard cells of Vicia faba L. is enhanced by fusicoccin and suppressed by abscisic acid

    Energy Technology Data Exchange (ETDEWEB)

    Du, Z.; Aghoram, K.; Outlaw, W.H. Jr.

    1996-12-31

    Plants regulate water loss and CO{sub 2} gain by modulating the aperture sizes of stomata that penetrate the epidermis. Aperture size itself is increased by osmolyte accumulation and consequent turgor increase in the pair of guard cells that flank each stoma. Guard-cell phosphoenolpyruvate carboxylase, which catalyzes the regulated step leading to malate synthesis, is crucial for charge and pH maintenance during osmolyte accumulation. Regulation of this cytosolic enzyme by effectors is well documented, but additional regulation by posttranslational modification is predicted by the alteration of PEPC kinetics during stomatal opening. In this study, the authors have investigated whether this alteration is associated with the phosphorylation status of this enzyme. Using sonicated epidermal peels (isolated guard cells) pre-loaded with {sub 32}PO{sub 4}, the authors induced stomatal opening and guard-cell malate accumulation by incubation with 5 {micro}M fusicoccin (FC). In corroboratory experiments, guard cells were incubated with 5 {micro}M fusicoccin (FC). In corroboratory experiments, guard cells were incubated with the FC antagonist, 10 {micro}M abscisic acid (ABA). The phosphorylation status of PEPC was assessed by immunoprecipitation, electrophoresis, immunoblotting, and autoradiography. PEPC was phosphorylated when stomata were stimulated to open, and phosphorylation was lessened by incubation with ABA.

  1. A comparative study of drug resistance mechanism associated with active site and non-active site mutations: I388N and D425G mutants of acetyl-coenzyme-A carboxylase.

    Science.gov (United States)

    Zhu, Xiao-Lei; Yang, Guang-Fu

    2012-03-01

    A major concern in the development of acetyl-CoA carboxylase-inhibiting (ACCase; EC 6.4.1.2) herbicides is the emergence of resistance as a result of the selection of distinct mutations within the CT domain. Mutations associated with resistance have been demonstrated to include both active sites and non-active sites, including Ile-1781-Leu, Trp- 2027-Cys, Ile-2041-Asn, Asp-2078-Gly, and Gly-2096-Ala (numbered according to the Alopecurus myosuroides plastid ACCase). In the present study, extensive computational simulations, including molecular dynamics (MD) simulations and molecular mechanics-Poisson-Boltzmann surface area (MM/PBSA) calculations, were carried out to compare the molecular mechanisms of active site mutation (I388N) and non-active site mutation (D425G) in Alopecurus myosuroides resistance to some commercial herbicides targeting ACCase, including haloxyfop (HF), diclofop (DF) and fenoxaprop (FR). All of the computational model and energetic results indicated that both I388N and D425G mutations have effects on the conformational change of the binding pocket. The π-π interaction between ligand and Phe377 and Tyr161' residues, which make an important contribution to the binding affinity, was decreased after mutation. As a result, the mutant-type ACCase has a lower affinity for the inhibitor than the wild-type enzyme, which accounts for the molecular basis of herbicidal resistance. The structural and mechanistic insights obtained from the present study will deepen our understanding of the interactions between ACCase and herbicides, which provides a molecular basis for the future design of a promising inhibitor with low resistance risk. PMID:22242795

  2. Rapid switch of hepatic fatty acid metabolism from oxidation to esterification during diurnal feeding of meal-fed rats correlates with changes in the properties of acetyl-CoA carboxylase, but not of carnitine palmitoyltransferase I.

    Science.gov (United States)

    Moir, A M; Zammit, V A

    1993-01-01

    The effects of the ingestion of a meal on the partitioning of hepatic fatty acids between oxidation and esterification were studied in vivo for meal-fed rats. The time course for the reversal of the starved state was extremely rapid and the process was complete within 2 h, in marked contrast with the reversal of the effects of starvation in rats fed ad libitum [A. M. B. Moir and V. A. Zammit (1993) Biochem. J. 289, 49-55]. This rapid reversal occurred in spite of the fact that, in the liver of the meal-fed animals before feeding, a similar degree of partitioning of fatty acids in favour of oxidation was observed as in 24 h-starved rats (previously fed ad libitum). This suggested that the lower degree of ketonaemia observed in meal-fed rats before a meal is not due to the inability of acylcarnitine formation to compete successfully with esterification of fatty acids to the glycerol moiety. Investigation of the possible mechanisms that could contribute towards the rapid switching-off of fatty acid oxidation revealed that this was correlated with a very rapid rise and overshoot in hepatic malonyl-CoA concentration, but not with any change in the activity, or sensitivity to malonyl-CoA, of the mitochondrial overt carnitine palmitoyltransferase (CPT I). The role of these two parameters in the reversal of fasting-induced hepatic fatty acid oxidation was thus the inverse of that observed previously for refed 24 h-starved rats. The rapid increase in [malonyl-CoA] was accompanied by an immediate and complete reversion of the kinetic characteristics (Ka for citrate, expressed/total activity ratio) of acetyl-CoA carboxylase to those found in the post-meal animals, again in contrast with the time course observed in refed 24 h-starved rats [A. M. B. Moir and V. A. Zammit (1990) Biochem. J. 272, 511-517]. The rapidity with which these changes occurred was specific to the partitioning of acyl-CoA; the meal-induced diversion of glycerolipids towards phospholipid synthesis and the

  3. Effects of manganese-excess on CO2 assimilation, ribulose-1,5-bisphosphate carboxylase/oxygenase, carbohydrates and photosynthetic electron transport of leaves, and antioxidant systems of leaves and roots in Citrus grandis seedlings

    Directory of Open Access Journals (Sweden)

    Tang Ning

    2010-03-01

    Full Text Available Abstract Background Very little is known about the effects of manganese (Mn-excess on citrus photosynthesis and antioxidant systems. Seedlings of sour pummelo (Citrus grandis were irrigated for 17 weeks with nutrient solution containing 2 μM (control or 500 μM (excess MnSO4. The objective of this study were to understand the mechanisms by which Mn-excess leads to a decrease in CO2 assimilation and to test the hypothesis that Mn-induced changes in antioxidant systems differ between roots and leaves. Results Mn-excess decreased CO2 assimilation and stomatal conductance, increased intercellular CO2 concentration, but did not affect chlorophyll (Chl level. Both initial and total ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco activity in Mn-excess leaves decreased to a lesser extent than CO2 assimilation. Contents of glucose, fructose, starch and total nonstructural carbohydrates did not differ between Mn-excess leaves and controls, while sucrose content was higher in the former. Chl a fluorescence (OJIP transients from Mn-excess leaves showed increased O-step and decreased P-step, accompanied by positive L- and K-bands. Mn-excess decreased maximum quantum yield of primary photochemistry (Fv/Fm and total performance index (PItot,abs, but increased relative variable fluorescence at I-steps (VI and energy dissipation. On a protein basis, Mn-excess leaves displayed higher activities of monodehydroascorbate reductase (MDAR, glutathione reductase (GR, superoxide dismutase (SOD, catalase (CAT and guaiacol peroxidase (GPX and contents of antioxidants, similar ascorbate peroxidase (APX activities and lower dehydroascorbate reductase (DHAR activities; while Mn-excess roots had similar or lower activities of antioxidant enzymes and contents of antioxidants. Mn-excess did not affect malondialdehyde (MDA content of roots and leaves. Conclusions Mn-excess impaired the whole photosynthetic electron transport chain from the donor side of photosystem II

  4. Influence of the nitrate concentration and source in the incorporation of 14{sub C}O2 by the RuBP-carboxylase from wheat (triticum aestivum) and maize (zea mays); Influencia de la concentracion y fuente de nitrogeno en la incorporacion de 14{sub C}O2 por la RuBp-carboxilasa de trigo (triticum aewtivum) y maiz (zea mays)

    Energy Technology Data Exchange (ETDEWEB)

    Saez Angulo, R. M.; Gines Diaz, M. J.; Garcia Pineda, M. D.

    1982-07-01

    The effect of the concentration and source of nitrogen in the culture media has been studied regarding its influence in the activity of the RuBP-carboxylase from wheat and maize during the first month of development. Wheat and maize has been chosen as plants representatives of two different types of CO{sub 2} assimilation: C3 and M- respectively. Plants have been grown in hydroponic media and under temperature, humidity and nutrient salts control. A negative effect of NH{sub 4} has been observed in the enzymatic activity of wheat seedlings, being this effect more remarkable as NH{sub 4} concentration increases and as long the time of treatment. In our experimental conditions the most favorable source of nitrogen has been N0{sub 3}NH{sub 4}. The specific activity of the enzyme from wheat is about four times higher than in maize, even it decreases with time. This decreasing has not been observed in maize, with the exception of total absence of nitrogen in the media. We have not seen significant differences between the two photo periods which have been tested. Also, no differences have been found in the enzyme activities at the different NO{sub 3}NH{sub 4} concentrations assayed, and it seems that RuBP-carboxylase metabolism is only affected in the case of absolute stress. (Author) 20 refs.

  5. Study of the properties of Ribulose 1,5-biphosphate carboxylase/oxygenase from maize (Zea mays) and wheat (Triticum aestivum) by incorporation of 14{sub C}O2; Estudio de las propiedades de la Ribulosa-1,5-Difosfato Carboxilasa/Oxigenasa de maiz (Zea Mais) y de trigo (Triticum Aestivum), por incorporacion de CO{sub 2} marcado con 14{sub C}O2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. D.; Saez, R. M.

    1982-07-01

    After a bibliographic review of the properties of RuBP-carboxylase/oxygenase, a methodology is described which allows the treatment of a large number of samples for the assay of the enzyme activity. 14{sup C}O{sub 3}HNa is used as a marker for the counting of the incorporated radioactivity as acid insoluble material. 14''CC{sub 2} from the labeled sodium bicarbonate is the species used by the enzyme both as an activator as well as a substrate. The following experiments are described and its results given: Determination of the optimal conditions for the activation of the enzyme; study of the kinetics of the catalytic action; effect of the Mg{sup 2} concentration and determination of the Km{sub (s)} from CO{sub 2} and ribulose 1,5-biphosphate; also determination of the optimum pH at different concentrations of CO{sub 2}2 and Mg{sup 2}. (Author) 64 refs.

  6. 高脂饮食对老年大鼠骨骼肌脂肪酸含量及乙酰辅酶A羧化酶表达和活性的影响%Effects of high-fat diet on fatty acid metabolism, expression and activity of acetyl-coenzyme A carboxylase in skeletal muscle in aged rats

    Institute of Scientific and Technical Information of China (English)

    胡淑国; 宋光耀; 王敬; 高宇

    2010-01-01

    目的 探讨增龄和高脂饮食对大鼠骨骼肌脂肪酸含量及乙酰辅酶A羧化酶(acetyl-coenzyme A carboxylase,ACC)表达和活性的影响.方法 将22~24月龄雄性Wistar大鼠随机分为老年对照组和高脂组;4~5月龄大鼠作为青年对照组.老年对照组和青年对照组给基础饲料,高脂组给予高脂饲料,喂养8周.用高胰岛素-正葡萄糖钳夹实验评价各组大鼠胰岛素敏感性,用全自动生化分析仪测定骨骼肌三酰甘油,用荧光分光光度计测定骨骼肌总的长链脂酰辅酶A含量,用Western-blot方法测定骨骼肌ACC、和磷酸化ACC(P-ACC)蛋白表达.结果 (1)老年对照组空腹血糖、胰岛索和游离脂肪酸高于青年对照组,高脂组上述几项指标进一步升高,并且出现血清三酰甘油和总胆固醇水平增高;(2)老年对照组葡萄糖输注率(glucose infusion rates,GIR)低于青年对照组,高脂组GIR低于老年对照组,高脂组GIR在8周末低于4周末;(3)老年对照组骨骼肌三酰甘油及长链脂酰辅酶A含量高于青年对照组,高脂组与老年对照组比较进一步升高;(4)老年对照组与青年对照组之间、高脂组与老年对照组之间骨骼肌ACC蛋白表达均无明显变化(P>0.05);骨骼肌P-ACC蛋白水平在老年对照组低于青年对照组,高脂组与老年对照组比较进一步降低(P0.05). The protein levels of P-ACC in skeletal muscle were lower in OC group, and much lower in HF group than in YC group (P<0.05 or P<0.01). Conclusions Compared with young rats, abnormal fatty acid metabolism and insulin resistance always exist in aged rats. High-fat feeding results in a significant increase in lipid content in skeletal muscle. Alterations of ACC activity may contribute to fat accumulation in skeletal muscle and insulin resistance.

  7. Crescimento e competitividade de biótipos de capim-colchão resistente e suscetível aos herbicidas inibidores da acetil coenzima A carboxilase Growth and competitiveness of biotypes of crabgrass resistant and susceptible to acetyl coenzyme A carboxylase inhibiting herbicides

    Directory of Open Access Journals (Sweden)

    Ramiro Fernando López Ovejero

    2007-01-01

    Full Text Available O objetivo deste trabalho foi comparar o crescimento e a habilidade competitiva de dois biótipos de capim-colchão (Digitaria ciliaris, um resistente (R e outro suscetível (S aos herbicidas inibidores da acetil coenzima A carboxilase. O crescimento dos biótipos foi determinado pela coleta da matéria seca das plantas, aos 14, 21, 25, 28, 34, 42, 49, 57, 65, 72, 78, 86, 101, 111 e 118 dias após emergência (DAE. Os dados de massa de matéria seca foram ajustados ao modelo logístico e, também, utilizados para a obtenção da taxa de crescimento absoluto. Para avaliar a habilidade competitiva intra-específica e interespecífica, foram instalados cinco experimentos com o uso do método substitutivo. Compararam-se os biótipos R e S entre si e cada um destes com a cultura da soja, quando semeada no mesmo dia ou sete dias após a semeadura das plantas daninhas. As proporções de plantas entre as espécies ou biótipos utilizados foram: 5:0; 4:1; 3:2; 2:3; 1:4 e 0:5. Os biótipos de capim-colchão apresentaram acúmulo de matéria seca, crescimento absoluto e competição interespecífica semelhantes, e a redução da matéria seca da soja foi similar na presença dos biótipos R e S, o que sugere que ambos os biótipos de capim-colchão possuem a mesma adaptabilidade ecológica.The objective of this work was to compare the growth and the competitive ability of two crabgrass (Digitaria ciliaris biotypes, one resistant (R and other susceptible (S to the acetyl coenzyme A carboxylase inhibiting herbicides. Biotypes growth was determined by collecting the plant dry mass at 14, 21, 25, 28, 34, 42, 49, 57, 65, 72, 78, 86, 101, 111, and 118 days after emergence (DAE. Data of dry mass were adjusted to a logistic model, and were also used to calculate the absolute growth rate. Five experiments were installed to evaluate the intraspecific and interspecific competitive ability, using the substitutive method. The biotypes R and S were compared between

  8. 新生儿筛查疑诊3-甲基巴豆酰辅酶A羧化酶缺乏症患儿的随访及基因分析%Follow up and gene mutation analysis in cases suspected as 3-methylcrotonyl-coenzyme A carboxylase deficiency by neonatal screening

    Institute of Scientific and Technical Information of China (English)

    叶军; 宫丽霏; 韩连书; 邱文娟; 张惠文; 高晓岚; 金晶; 许浩; 顾学范

    2014-01-01

    发育正常;中国患儿MCCC1突变多见,发现9种新突变,c.ins1680A可能是热点突变.%Objective 3-Methylcrotonyl-coenzyme A carboxylase deficiency (MCCD) is an autosomal recessive inborn error of leucine catabolism.The cases suspected as MCCD detected by neonatal screening are not rare.The aim of the study was to investigate the clinical outcomes in cases suspected as MCCD by neonatal screening.The second aim was to investigate the mutation spectrum of MCC gene in Chinese population and hotspot mutation.Method Forty-two cases (male 33,female 9),who had higher blood 3-hydroxy-isovalerylcarnitine (C5-OH) levels(cut-off <0.6 μmol/L) detected by neonatal screening using MS/MS,were recruited to this study during Sept.2011 to Mar.2013.The C5-OH concentrations were [0.84(0.61-20.15) μmol/L] in 42 cases at the screening recall.Five cases were firstly diagnosed as maternal MCCD,6 cases as benign MCCD and 31 cases were suspected as MCCD.To follow up the height,weight,mental development,blood C5-OH concentrations and urinary 3-methylcrotonyl-glycine (3-MCG) and 3-hydroxy isovalerate (3-HIVA) in order to investigate the clinical outcome.The MCCC1 and MCCC2 gene mutation were analyzed for some cases.The novel gene variants were evaluated,and the influence of novel missense variants on the protein structure and function were predicted by PolyPhen-2,SIFT,UniProt and PDB software.Result (1) Forty-two cases had no symptoms,their physical and mental development were normal in the last visit at the median ages of 29 months,the oldest age of follow up was nearly 9 years.(2) Gene mutation analysis was performed for 29 cases with informed consent signed by parents.Fourteen different mutations were identified in 19 cases.The mutations in MCCC1 gene accounted for 86%,the most common mutation was c.ins1680A,(accounted for 40%).Nine kinds of novel variant were detected including 211AG > CC/p.Q74P,c.295G > A/p.G99S,c.764A > C/p.H255P,c.964G > A/p.E322K,c.1331G > A/p.R444H,c.1124delT,c.39_58del

  9. Dithiothreitol decreases the thermal stability and unfolding cooperativity of ribulose-1, 5-bisphosphate carboxylase/oxygenase

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Plant rubisco consists of eight large subunits (55 kD) encoded by chloroplast gene and eight small subunits (15 kD) encoded by nuclear gene. There are abundant cysteine residues that do not form disulfide bonds in native rubisco. Differential scanning calorimetry has been used to study some plant rubisco and suggested an irreversible two-state denaturation due to the high cooperativity in subunits. By comparing the data from circular dichroism, fluorescence, differential scanning calorimetry, SDS electrophoresis, and activity assays in the absence or presence of DTT, we suggest that the formation of disulfide bonds in subunits during the early thermal unfolding may increase the thermal stability and the thermal unfolding cooperativity of rubisco.

  10. Genome sequence of carboxylesterase, carboxylase and xylose isomerase producing alkaliphilic haloarchaeon Haloterrigena turkmenica WANU15

    Directory of Open Access Journals (Sweden)

    Samy Selim

    2016-03-01

    Full Text Available We report draft genome sequence of Haloterrigena turkmenica strain WANU15, isolated from Soda Lake. The draft genome size is 2,950,899 bp with a G + C content of 64% and contains 49 RNA sequence. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession no. LKCV00000000.

  11. Role of Phospho enol pyruvate Carboxylase in the Adaptation of a Tropical Forage Grass to Low-Phosphorus Acid Soils

    OpenAIRE

    Begum, Hasna Hena; Osaki, Mitsuru; Nanamori, Masahito; Watanabe, Toshihiro; Shinano, Takuro; Rao, Idupulapati M.

    2006-01-01

    As Brachiaria hybrid cv. 'Mulato' has adapted to acid soils with extremely low phosphorus (P) contents, its low-P-tolerance mechanisms were investigated and compared with those of wheat (Triticum aestivum L.) and rice (Oryza sativa L. cv. 'Kitaake'). Among the three plant species, the highest P-use efficiency (PUE) in low-P soil was recorded in the Brachiaria hybrid, which increased remarkably under P-deficiency and soil acidity, while P-deficiency had less effect on the PUE of wheat and rice...

  12. Underlying Resistance Mechanisms in the Cynosurus echinatus Biotype to Acetyl CoA Carboxylase-Inhibiting Herbicides

    OpenAIRE

    Fernández, Pablo; Alcántara-de la Cruz, Ricardo; Cruz-Hipólito, Hugo; Osuna, María D.; Prado, Rafael

    2016-01-01

    Hedgehog dogtail (Cynosurus echinatus) is an annual grass, native to Europe, but also widely distributed in North and South America, South Africa, and Australia. Two hedgehog dogtail biotypes, one diclofop-methyl (DM)-resistant and one DM-susceptible were studied in detail for experimental dose-response resistance mechanisms. Herbicide rates that inhibited shoot growth by 50% (GR50) were determined for DM, being the resistance factor (GR50R/GR50S) of 43.81. When amitrole (Cyt. P450 inhibitor)...

  13. Underlying Resistance Mechanisms in the Cynosurus echinatus Biotype to Acetyl CoA Carboxylase-Inhibiting Herbicides.

    Science.gov (United States)

    Fernández, Pablo; Alcántara-de la Cruz, Ricardo; Cruz-Hipólito, Hugo; Osuna, María D; De Prado, Rafael

    2016-01-01

    Hedgehog dogtail (Cynosurus echinatus) is an annual grass, native to Europe, but also widely distributed in North and South America, South Africa, and Australia. Two hedgehog dogtail biotypes, one diclofop-methyl (DM)-resistant and one DM-susceptible were studied in detail for experimental dose-response resistance mechanisms. Herbicide rates that inhibited shoot growth by 50% (GR50) were determined for DM, being the resistance factor (GR50R/GR50S) of 43.81. When amitrole (Cyt. P450 inhibitor) was applied before treatment with DM, the R biotype growth was significantly inhibited (GR50 of 1019.9 g ai ha(-1)) compared with the GR50 (1484.6 g ai ha(-1)) found for the R biotype without pretreatment with amitrole. However, GR50 values for S biotype do not vary with or without amitrole pretreatment. Dose-response experiments carried out to evaluate cross-resistance, showed resistance to aryloxyphenoxypropionate (APP), cyclohexanedione (CHD) and phenylpyrazoline (PPZ) inhibiting herbicides. Both R and S biotypes had a similar (14)C-DM uptake and translocation. The herbicide was poorly distributed among leaves, the rest of the shoot and roots with unappreciable acropetal and/or basipetal DM translocation at 96 h after treatment (HAT). The metabolism of (14)C-DM, D-acid and D-conjugate metabolites were identified by thin-layer chromatography. The results showed that DM resistance in C. echinatus is likely due to enhanced herbicide metabolism, involving Cyt. P450 as was demonstrated by indirect assays (amitrole pretreatment). The ACCase in vitro assays showed that the target site was very sensitive to APP, CHD and PPZ herbicides in the C. echinatus S biotype, while the R biotype was insensitive to the previously mentioned herbicides. DNA sequencing studies confirmed that C. echinatus cross-resistance to ACCase inhibitors has been conferred by specific ACCase double point mutations Ile-2041-Asn and Cys-2088-Arg. PMID:27148285

  14. Electron transport, pep carboxylase activity, and maximal net co2 assimilation exhibit coordinated and proportional decline with loss of hydraulic conductance during water stress in Zea mays

    Science.gov (United States)

    Efforts to improve the photosynthetic performance of species are presently focused on leaf-level traits (e.g., quantum efficiency, mesophyll osmoregulation, stress protein regulation). Here, we emphasize that efforts to improve plant performance in arid environments would benefit from also consider...

  15. aP2-Cre-mediated inactivation of acetyl-CoA carboxylase 1 causes growth retardation and reduced lipid accumulation in adipose tissues

    Science.gov (United States)

    Adipose tissue is one of the major sites for fatty acid synthesis and lipid storage. We generated adipose (fat)-specific ACC1 knockout (FACC1KO) mice using the aP2-Cre/loxP system. FACC1KO mice showed prenatal growth retardation; after weaning, however, their weight gain was comparable to that of wi...

  16. Influence of oxygen on the level of ribulose-1.5-bisphosphate carboxylase/oxygenase (Rubisco): only a substrate or also an inhibitor?

    International Nuclear Information System (INIS)

    Influence of oxygen upon the carboxylation of ribulose-1,5-bisphosphate (RuBP) in wheat (Triticum aestivum) leaves was studied at the steady state photosynthesis and at sharp transfers to a higher or to a lower 02 concentration. In leaves exhibiting a 26% Warburg effect at the steady state photosynthesis in the saturating light, no inhibition of carboxylation by oxygen was observed when the rate was measured by means of labelling during a 0.2-s exposure. The radioactivity of the extracts and of the residue was measured by means of a scintillation counter. The RuBP content of leaves was estimated by the post illumination tracer uptake at the exposure to 10 000 ppm 14CO2. Linearity of the measured carboxylation rate to the C02 concentration over the range from 0 to 100% showed that the uptake represented a bimolecular reaction. The rate estimated by the method applied was a characteristic of the primary binding of C02, a partial reaction of carboxylation, not of the total turnover of the catalytic site. Independence of this partial reaction of O2 indicated that oxygen did not inhibit carboxylation, neither did it cause any significant reduction in the pool of the immediate C02 acceptor, the Rubisco-RuBP complex, despite its role as an alternative substrate. 3 figs., 2 tabs.; 13 refs

  17. S-NITROSYLATED PROTEINS OF A MEDICINAL, CAM PLANT KALANCHOE PINNATA: RIBULOSE-1, 5-BISPHOSPATE CARBOXYLASE/OXYGENASE ACTIVITY TARGETED FOR INHIBITION

    Science.gov (United States)

    Nitric oxide (NO) is a new addition to signaling molecules that affect a myriad of processes in plants. However, the mechanistic details are scanty. NO post-translationally modifies proteins by S-nitrosylation of cysteines. Soluble S-nitrosoproteome of a medicinal, crassulacean acid metabolism (CAM)...

  18. Long-term effect of elevated CO2 on spatial differentiation of ribulose-1,5-bisphosphate carboxylase/oxygenase activity in Norway spruce canopy

    Czech Academy of Sciences Publication Activity Database

    Hrstka, M.; Urban, Otmar; Marek, Michal V.

    2005-01-01

    Roč. 43, č. 2 (2005), s. 211-216. ISSN 0300-3604 R&D Projects: GA MŠk(CZ) LN00A141; GA MŽP(CZ) SM/640/18/03; GA MŠk(CZ) OC E21.001 Institutional research plan: CEZ:AV0Z6087904 Keywords : down-regulation * photosynthesis * sun and shade needles * vertical profile Subject RIV: ED - Physiology Impact factor: 0.810, year: 2005

  19. A single nucleotide polymorphism within the acetyl-coenzyme A carboxylase beta gene is associated with proteinuria in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Maeda, Shiro; Kobayashi, Masa-aki; Araki, Shin-ichi;

    2010-01-01

    It has been suggested that genetic susceptibility plays an important role in the pathogenesis of diabetic nephropathy. A large-scale genotyping analysis of gene-based single nucleotide polymorphisms (SNPs) in Japanese patients with type 2 diabetes identified the gene encoding acetyl-coenzyme A ca...

  20. Impact of ozone on the activity and quantity of ribulose bisphosphate carboxylase/oxygenase in potato foliage and its relation to premature senescence

    Energy Technology Data Exchange (ETDEWEB)

    Dann, M.S.

    1988-01-01

    Plants, 26 days old, were exposed to O{sub 3} for five days in a controlled environment chamber. Initial and total activities and quantity of enzyme declined in both O{sub 3}-treated and control plants. Ozone accelerated the decline and produced a significantly greater decrease in activity and quantity by the fifth day of O{sub 3} exposure. Percent activation of the enzyme did not change. Enzyme activity and quantity of O{sub 3}-treated plants remained below control levels throughout a seven-day post-exposure observation period. Ozone may accelerate the decline in rubisco by increasing enzyme acceptability to proteases. To test this hypothesis, rubisco was purified from Norland potato foliage and the enzyme exposed to O{sub 3} or oxygen (O{sub 2}) in vitro. Following oxidant treatment, the extract was treated with exogenous protease. Oxidant treatment reduced the quantity of rubisco an average of 15%. Addition of protease further reduced the quantity by another 30% after O{sub 3} but no O{sub 2} treatment.

  1. Abundance and distribution of archaeal acetyl-CoA/propionyl-CoA carboxylase genes indicative for putatively chemoautotrophic Archaea in the tropical Atlantic's interior

    NARCIS (Netherlands)

    Bergauer, K.; Sintes, E.; van Bleijswijk, J.; Witte, H.; Herndl, G.J.

    2013-01-01

    Recently, evidence suggests that dark CO2 fixation in the pelagic realm of the ocean does not only occur in the suboxic and anoxic water bodies but also in the oxygenated meso- and bathypelagic waters of the North Atlantic. To elucidate the significance and phylogeny of the key organisms mediating d

  2. Phosphoenolpyruvate carboxylase, NADP-malic enzyme, and pyruvate, phosphate dikinase are involved in the acclimation of Nicotiana tabacum L. to drought stress

    Czech Academy of Sciences Publication Activity Database

    Doubnerová-Hýsková, V.; Miedzińska, L.; Dobrá, Jana; Vaňková, Radomíra; Ryšlavá, H.

    2014-01-01

    Roč. 171, č. 5 (2014), s. 19-25. ISSN 0176-1617 R&D Projects: GA MŠk 1M0505 Institutional support: RVO:61389030 Keywords : Drought * NADP-malic enzyme * Nicotiana tabacum L. Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.557, year: 2014

  3. Changes in mRNA levels and polypeptide subunits of ribulose 1,5-bisphosphate carboxylase in response to supplementary ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Pea plants (Pisum sativum L., cv. Greenfeast) were grown for 17d (150 μmol photons m−2 s−1; 12h light/12 h dark) and then exposed to moderate levels of supplementary ultraviolet-B radiation (UV-B: 280–320 nm) during the light cycle. The total soluble leaf protein, maximum Rubisco activity, polypeptide and mRNA transcript levels for Rubisco subunits were then determined in the mature third leaf pair from the base of the plants. Total soluble protein per unit leaf area showed little change after 1 d but declined by 33% during 3d of UV-B exposure. However, there was no change on a unit chlorophyll basis. Total RNA per unit area declined by 15% and 37% after 1 or 3d of UV-B treatment, respectively. Maximum Rubisco activity declined by 38% after 1 d and 71% after 3d of UV-B exposure. Rubisco polypeptide subunits showed some decrease (∼16%) after 1d exposure, but declined by 56% over 3d. The decrease in Rubisco is probably the major reason for the reduction in soluble protein. In contrast to the relatively slow decline in total soluble protein and Rubisco, the level of the mRNA transcripts for both rbc L and rbc S showed a dramatic decrease within hours of UV-B exposure. The mRNA transcripts for rbc S were reduced to >20% of control values after 4h of UV-B exposure, while the rbc L transcripts were reduced by 60% after 8h. Further exposure to UV-B reduced the mRNA transcripts to either trace or undetectable levels. The decrease in rbc S mRNA levels with the UV-B exposure can be partially ameliorated by higher photosynthetically active irradiance during the period of UV-B exposure. Plants that were exposed to supplementary UV-B radiation for short periods (4h or 8h) and returned to control conditions, showed no recovery after 24h. However, after a further 2d, the rbc L and rbc S mRNA transcripts had recovered to ca. 60% of the control values, showing that the effect upon the mRNA transcripts is a reversible response. (author)

  4. The nature and alternate rates of the ribulose 1,5-bisphosphate (RuBP) carboxylase/oxygenase (Rubisco) oxygenation intermediate

    Energy Technology Data Exchange (ETDEWEB)

    Harpel, M.R.; Chen, Yuh-Ru; Hartman, F.C.

    1995-12-31

    Mutant ribulose 1,5-bisphosphate (RuBP) were employed to investigate the partitioning of carbon flow between photosynthesis or photorespiration. Previous functional and structural studies implicate active site Lys329 and Glu48 or R. rubrum RuBp in promoting addition of CO2 to the RuBP-enediol. Two novel O2-dependent side products generated by the K329A and E49Q mutants provided insight into RuBP oxygenase intermediate and roles of Lys329 and Glu48 in oxygenation.

  5. Mechanism and Significance of Post-Translational Modifications in the Large (LS) and Small (SS) Subunits of Ribulose-1,5 Bisphosphate Carboxylase/Oxygenase

    Energy Technology Data Exchange (ETDEWEB)

    Houtz, Robert, L.

    2012-11-09

    This project focused on a molecular and biochemical characterization of the protein methyltransferases responsible for methylation of the LS and SS in Rubisco, and the associated functional consequences accompanying these modifications. Our results provided some of the most informative structural and mechanistic understandings of SET domain protein methyltransferases. These results also positioned us to provide the first unambiguous assignment of the kinetic reaction mechanism for SET-domain protein methyltransferases, and to design and engineer an alternative substrate for Rubisco LSMT, enabling substrate specificity and functional significance studies. We demonstrated that the minimal substrate recognized by Rubisco LSMT is free lysine as well as monomethyllysine, an observation corroborated both by structural analyses as well as enzymatic activity and subsequent product distribution analyses. Ternary complexes between Rubisco LSMT and free lysine compared to complexes with monomethyllysine demonstrated that the structural basis for multiple methyl group additions is a consequence of hydrogen-bond driven spatial shifts in the amino group of Lys-14, which maintains the direct in-line geometry necessary for SN2 nucleophilic attack. The structural observations are also consistent with the previous proposal that the multiplicity of methyl group additions takes place through a processive mechanism, with successive methyl group additions to an enzyme protein complex which does not disassociate prior to the formation of trimethyllysine. This mechanism has important implications, since the regulation of gene expression by SET domain histone methyltransferases is not only dependent on site-specific lysine methylation, but also the degree of methylation. We examined the kinetic reaction mechanism for three different types of SET domain protein methyltransferases, each under conditions supporting mono-, di-, or trimethyllysine formation corroborated by product analyses. Additionally, the tight initial binding of Rubisco LSMT to Rubisco also allowed us to design a novel immobilized complex between Rubisco and Rubisco LSMT, which allowed for an unambiguous demonstration of the requirement for trimethyllysine formation prior to disassociation of the Rubisco LSMT:Rubisco complex, and therefore proof of the processive mechanism for methyl group transfer. These kinetic studies also demonstrated that an important factor has been overlooked in all kinetic analyses of SET domain protein methyltransferases reported to date. This factor is the influence of the low turnover number for SET domain protein methyltransferases and how, relative to the time-frame of kinetic enzyme assays, this can generate changes in kinetic profiles shifting reciprocal plot patterns from random/ordered bi-bi to the real kinetic reaction mechanism plots of ping-pong. Although the ternary complexes of Rubisco LSMT with S-Adenosylhomocysteine and lysine and monomethyllysine were informative in regard to reaction mechanism, they were not helpful in identifying the mechanism used by Rubisco LSMT for determining substrate specificity. We were unsuccessful at obtaining ternary complexes of Rubisco LSMT with bound synthetic polypeptide substrates, as has been reported for several histone methyltransferases. However, we were able to model a polypeptide sequence corresponding to the N-terminal region of the LS of Rubisco into the apparent substrate binding cleft in Rubisco LSMT. Knowledge of the determinants of polypeptide substrate specificity are important for identifying possible alternate substrates, as well as the possibility of generating more desirable substrates amenable to site-directed mutagenesis experiments unlike Rubisco. We determined that Rubisco LSMT is capable of methylating synthetic polypeptide mimics of the N-terminal region of the LS, both free as well as conjugated to keyhole limpet hemacyanin, but with considerable less efficiency than intact holoenzyme.

  6. Protein (Cyanobacteria): 246918 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 5-bisphosphate carboxylase small subunit Moorea producens 3L MKTLPKERRYETLSYLPPLSDAQIMRQVEYILAEGYIPAIEFNESSEPEIYYWTLWKLPLFKATSPKDVLAEVDECRSEYRDCYIRVVGFDNVKQCQVLSFIIHKPNEGVSRSRW ...

  7. Arabidopsis CDS blastp result: AK068172 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK068172 J013129D15 At2g37690.1 phosphoribosylaminoimidazole carboxylase, putative / AIR ... carboxy ... carboxylase, chloroplast precursor (EC 4.1.1.21) (AIR ... carboxylase) (AIR C) {Vigna aconitifolia}; contains ... Pfam profiles PF02222: ATP-grasp domain, PF00731: AIR ... carboxylase 0.0 ...

  8. GenBank blastx search result: AK061906 [KOME

    Lifescience Database Archive (English)

    Full Text Available moderately similar to ACETYL-/PROPIONYL-COENZYME A CARBOXYLASE ALPHA CHAIN [CONTAINS: BIOTIN CARBOXYLASE (EC 6.3.4.14); BIOTIN CARBOXYL CARRIER PROTEIN (BCCP)].|PRI PRI 1e-102 +1 ...

  9. Solar ultraviolet radiation affects the activity of ribulose-1, 5-bisphosphate carboxylase-oxygenase and the composition of photosynthetic and xanthophyll cycle pigments in the intertidal green alga Ulva lactuca L.

    NARCIS (Netherlands)

    Bischof, K; Krabs, G; Wiencke, C; Hanelt, D

    2002-01-01

    The effect of solar UV radiation on the physiology of the intertidal green macroalga Ulva lactuca L. was investigated. A natural Ulm community at the shore of Helgoland was covered with screening foils, excluding UV-B or UV-B + UV-A from the solar spectrum. In the sampled material, changes in the ac

  10. D-Xylose as a sugar complement regulates blood glucose levels by suppressing phosphoenolpyruvate carboxylase (PEPCK) in streptozotocin-nicotinamide-induced diabetic rats and by enhancing glucose uptake in vitro

    OpenAIRE

    Kim, EunJu; Kim, Yoo-Sun; Kim, Kyung-Mi; Jung, Sangwon; Yoo, Sang-Ho; Kim, Yuri

    2015-01-01

    BACKGROUND/OBJECTIVES Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. D-Xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of D-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS Wistar rats were divided into the following groups: (i...

  11. CO2 assimilation, ribulose-1,5-bisphosphate carboxylase/oxygenase, carbohydrates and photosynthetic electron transport probed by the JIP-test, of tea leaves in response to phosphorus supply

    Directory of Open Access Journals (Sweden)

    Chen Rong-Bing

    2009-04-01

    Full Text Available Abstract Background Although the effects of P deficiency on tea (Camellia sinensis (L. O. Kuntze growth, P uptake and utilization as well as leaf gas exchange and Chl a fluorescence have been investigated, very little is known about the effects of P deficiency on photosynthetic electron transport, photosynthetic enzymes and carbohydrates of tea leaves. In this study, own-rooted 10-month-old tea trees were supplied three times weekly for 17 weeks with 500 mL of nutrient solution at a P concentration of 0, 40, 80, 160, 400 or 1000 μM. This objective of this study was to determine how P deficiency affects CO2 assimilation, Rubisco, carbohydrates and photosynthetic electron transport in tea leaves to understand the mechanism by which P deficiency leads to a decrease in CO2 assimilation. Results Both root and shoot dry weight increased as P supply increased from 0 to 160 μM, then remained unchanged. P-deficient leaves from 0 to 80 μM P-treated trees showed decreased CO2 assimilation and stomatal conductance, but increased intercellular CO2 concentration. Both initial and total Rubisco activity, contents of Chl and total soluble protein in P-deficient leaves decreased to a lesser extent than CO2 assimilation. Contents of sucrose and starch were decreased in P-deficient leaves, whereas contents of glucose and fructose did not change significantly except for a significant increase in the lowest P leaves. OJIP transients from P-deficient leaves displayed a rise at the O-step and a depression at the P-step, accompanied by two new steps at about 150 μs (L-step and at about 300 μs (K-step. RC/CSo, TRo/ABS (or Fv/Fm, ETo/ABS, REo/ABS, maximum amplitude of IP phase, PIabs and PItot, abs were decreased in P-deficient leaves, while VJ, VI and dissipated energy were increased. Conclusion P deficiency decreased photosynthetic electron transport capacity by impairing the whole electron transport chain from the PSII donor side up to the PSI, thus decreasing ATP content which limits RuBP regeneration, and hence, the rate of CO2 assimilation. Energy dissipation is enhanced to protect P-deficient leaves from photo-oxidative damage in high light.

  12. Novel gamma-carboxyglutamic acid-containing peptides from the venom of Conus textile

    DEFF Research Database (Denmark)

    Czerwiec, Eva; Kalume, Dario E; Roepstorff, Peter;

    2006-01-01

    The cone snail is the only invertebrate system in which the vitamin K-dependent carboxylase (or gamma-carboxylase) and its product gamma-carboxyglutamic acid (Gla) have been identified. It remains the sole source of structural information of invertebrate gamma-carboxylase substrates. Four novel Gla...

  13. AcEST: DK947508 [AcEST

    Lifescience Database Archive (English)

    Full Text Available e bisphosphate carboxylase small c... 111 2e-23 tr|A6MZQ8|A6MZQ8_ORYSI Ribulose bisphosphate carboxylase sma...ll c... 111 2e-23 tr|A3CGJ9|A3CGJ9_ORYSJ Ribulose bisphosphate carboxylase small c... 111 2e-23 tr|A2ZJQ0|A2

  14. Biotin and biotinidase deficiency

    OpenAIRE

    Zempleni, Janos; Hassan, Yousef I.; Wijeratne, Subhashinee SK

    2008-01-01

    Biotin is a water-soluble vitamin that serves as an essential coenzyme for five carboxylases in mammals. Biotin-dependent carboxylases catalyze the fixation of bicarbonate in organic acids and play crucial roles in the metabolism of fatty acids, amino acids and glucose. Carboxylase activities decrease substantially in response to biotin deficiency. Biotin is also covalently attached to histones; biotinylated histones are enriched in repeat regions in the human genome and appear to play a role...

  15. Sequence Classification: 399396 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|15610104|ref|NP_217483.1| PROBABLE PYRUVATE CARB...OXYLASE PCA (PYRUVIC CARBOXYLASE) || http://www.ncbi.nlm.nih.gov/protein/15610104 ...

  16. Sequence Classification: 389632 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|31794143|ref|NP_856636.1| PROBABLE PYRUVATE CARB...OXYLASE PCA (PYRUVIC CARBOXYLASE) || http://www.ncbi.nlm.nih.gov/protein/31794143 ...

  17. InterProScan Result: CK523618 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available CK523618 CK523618_6_ORF1 9340A0F489CFC86C PANTHER PTHR18866 CARBOXYLASE:PYRUVATE/AC...ETYL-COA/PROPIONYL-COA CARBOXYLASE 2.1e-14 T IPR005482 unintegrated Molecular Function: ligase activity (GO:0016874) ...

  18. NCBI nr-aa BLAST: CBRC-XTRO-01-0052 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0052 ref|NP_795108.1| biotin ... carboxylase/biotin ... carboxyl carrier protein [Pseudomon ... as syringae pv. tomato str. DC3000] gb|AAO58803.1| biotin ... carboxylase/biotin ... carboxyl carrier protein [Pseud ...

  19. Locus: 5368 [ASTRA[Archive

    Lifescience Database Archive (English)

    Full Text Available Hs.371350 H. sapiens - S: gi|29824592|ref|NC_000021.3|NC_000021 NC_000021 Homo sapiens mRNA for ... HCS, complete cds. biotin -[acetyl-CoA-carboxylase] ligase activity | biotin - ... methylcrotonoyl-CoA-carboxylase] ligase activity | biotin -[methylmalonyl-CoA-carboxytransferase] ligase acti ...

  20. Locus: 4550 [ASTRA[Archive

    Lifescience Database Archive (English)

    Full Text Available Hs.449863 H. sapiens - S: gi|29824588|ref|NC_000017.5|NC_000017 NC_000017 Homo sapiens acetyl-Co ... ds ATP binding | acetyl-CoA carboxylase activity | biotin ... binding | biotin ... carboxylase activity | biotin ... car ...

  1. NCBI nr-aa BLAST: CBRC-XTRO-01-0052 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0052 ref|YP_272793.1| biotin ... carboxylase/biotin ... carboxyl carrier protein [Pseudomon ... as syringae pv. phaseolicola 1448A] gb|AAZ37384.1| biotin ... carboxylase/biotin ... carboxyl carrier protein [Pseud ...

  2. Disease: H00180 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00180 Holocarboxylase synthetase deficiency Holocarboxylase synthetase (HLCS) deficiency is an ... autosomal recessive disorder of biotin ... metabolism that results from holocarboxylase synth ... ases. In humans, four carboxylases are known to be biotin ylated by HLCS. They are pyruvate carboxylase, prop ...

  3. Disease: H00073 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00073 Pyruvate carboxylase deficiency Pyruvate carboxylase deficiency is an autosomal recessive ... 10: E74.4 MeSH: D015324 OMIM: 266150 PMID:18676167 Wang ... D, Yang H, De Braganca KC, Lu J, Yu Shih L, Brione ...

  4. Dicty_cDB: SFL170 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available |U23210.1 Debaryomyces occidentalis phosphoribosylaminoimidazole carboxylase (ADE2) gene, complete cds. 62 1...e-10 4 BT008606 |BT008606.1 Arabidopsis thaliana clone U50031 putative phosphoribosylaminoimidazole carboxyla...noimidazole carboxylase, complete cds. 56 3e-07 3 AF349948 |AF349948.1 Nicotiana tabacum phosphoribosylami...ana tabacum phosphoribosylaminoimidazole carboxylase (purEK) mRNA, partial cds. 6...slclwfafg fsrfh*tyk*s*iysttnstncndksfrsrs*rlgkntsn*rftssylc*rxqkkv Translated Amino Acid sequence (All Frames) Fram

  5. Main: 1JQO [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available 1JQO トウモロコシ Corn Zea mays L. Phosphoenolpyruvate Carboxylase 1 Name=Pep1; Synonyms=...FQAYTLKRIRDPNFKVTPQPPLSKEFADENKPAGLVKLNPASEYPPGLEDTLILTMKGIAAGMQNTG corn_1JQO.jpg ...

  6. Evolution of prokaryote and eukaryote lines inferred from sequence evidence

    Science.gov (United States)

    Hunt, L. T.; George, D. G.; Yeh, L.-S.; Dayhoff, M. O.

    1984-01-01

    This paper describes the evolution of prokaryotes and early eukaryotes, including their symbiotic relationships, as inferred from phylogenetic trees of bacterial ferredoxin, 5S ribosomal RNA, ribulose-1,5-biphosphate carboxylase large chain, and mitochondrial cytochrome oxidase polypeptide II.

  7. Main: 1WDD [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available 1WDD イネ Rice Oryza sativa L. Ribulose Bisphosphate Carboxylase Large Chain Precursor Name=Rbcl ... binitol-1, 5-Bisphosphate To Be Published Rubisco, Photosynthesis , Alpha/Beta Barrel, N-Methylmethionine, Post-Trans ...

  8. Disease: H01182 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H01182 Biotinidase deficiency; BTD deficiency; Late-onset multiple carboxylase deficiency Biotin ... eSH: D028921 OMIM: 253260 PMID:21696988 Wolf B The neurology ... of biotinidase deficiency. Mol Genet Metab 104:27- ...

  9. UniProt search blastx result: AK288054 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288054 J075152E14 P16134|RBS1_ACEAT Ribulose bisphosphate carboxylase small chain 1, chloropla ... ll subunit 1) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 1.00E-31 ...

  10. UniProt search blastx result: AK288054 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288054 J075152E14 P16137|RBS4_ACEAT Ribulose bisphosphate carboxylase small chain 4, chloropla ... ll subunit 4) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 3.00E-31 ...

  11. UniProt search blastx result: AK287599 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287599 J065050G24 P16138|RBS5_ACEAT Ribulose bisphosphate carboxylase small chain 5, chloropla ... ll subunit 5) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 6.00E-32 ...

  12. UniProt search blastx result: AK288517 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288517 J090043B03 P16137|RBS4_ACEAT Ribulose bisphosphate carboxylase small chain 4, chloropla ... ll subunit 4) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 9.00E-31 ...

  13. UniProt search blastx result: AK288054 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288054 J075152E14 P16138|RBS5_ACEAT Ribulose bisphosphate carboxylase small chain 5, chloropla ... ll subunit 5) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 4.00E-32 ...

  14. UniProt search blastx result: AK288517 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288517 J090043B03 P16136|RBS3_ACEAT Ribulose bisphosphate carboxylase small chain 3, chloropla ... ll subunit 3) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 1.00E-31 ...

  15. UniProt search blastx result: AK288517 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288517 J090043B03 P16138|RBS5_ACEAT Ribulose bisphosphate carboxylase small chain 5, chloropla ... ll subunit 5) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 7.00E-31 ...

  16. UniProt search blastx result: AK288517 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288517 J090043B03 P16134|RBS1_ACEAT Ribulose bisphosphate carboxylase small chain 1, chloropla ... ll subunit 1) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 2.00E-31 ...

  17. UniProt search blastx result: AK288517 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288517 J090043B03 P16135|RBS2_ACEAT Ribulose bisphosphate carboxylase small chain 2, chloropla ... 2) (Fragment) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 2.00E-31 ...

  18. UniProt search blastx result: AK287599 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287599 J065050G24 P16137|RBS4_ACEAT Ribulose bisphosphate carboxylase small chain 4, chloropla ... ll subunit 4) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 5.00E-31 ...

  19. UniProt search blastx result: AK288054 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288054 J075152E14 P16136|RBS3_ACEAT Ribulose bisphosphate carboxylase small chain 3, chloropla ... ll subunit 3) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 8.00E-32 ...

  20. UniProt search blastx result: AK287599 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287599 J065050G24 P16134|RBS1_ACEAT Ribulose bisphosphate carboxylase small chain 1, chloropla ... ll subunit 1) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 2.00E-31 ...

  1. UniProt search blastx result: AK287599 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287599 J065050G24 P16136|RBS3_ACEAT Ribulose bisphosphate carboxylase small chain 3, chloropla ... ll subunit 3) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 1.00E-31 ...

  2. UniProt search blastx result: AK288054 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288054 J075152E14 P16135|RBS2_ACEAT Ribulose bisphosphate carboxylase small chain 2, chloropla ... 2) (Fragment) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 1.00E-31 ...

  3. UniProt search blastx result: AK287599 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287599 J065050G24 P16135|RBS2_ACEAT Ribulose bisphosphate carboxylase small chain 2, chloropla ... 2) (Fragment) - Acetabularia acetabulum (Mermaid's wine ... glass) (Acetabularia mediterranea) 2.00E-31 ...

  4. UniProt search blastx result: AK288054 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288054 J075152E14 P29684|RBS_HEVBR Ribulose bisphosphate carboxylase small chain, chloroplast ... (RuBisCO small subunit) - Hevea brasiliensis (Para rubber ... tree) 7.00E-62 ...

  5. UniProt search blastx result: AK287599 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287599 J065050G24 P29684|RBS_HEVBR Ribulose bisphosphate carboxylase small chain, chloroplast ... (RuBisCO small subunit) - Hevea brasiliensis (Para rubber ... tree) 1.00E-61 ...

  6. UniProt search blastx result: AK288517 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288517 J090043B03 P29684|RBS_HEVBR Ribulose bisphosphate carboxylase small chain, chloroplast ... (RuBisCO small subunit) - Hevea brasiliensis (Para rubber ... tree) 1.00E-55 ...

  7. Protein (Cyanobacteria): 392180 [

    Lifescience Database Archive (English)

    Full Text Available ZP_07113914.1 1117:24513 1150:7038 1158:3915 272129:3709 Bifunctional protein birA (Includes: Biotin ... otin operon repressor; Biotin --(acetyl-CoA-carboxylase) synthetase (Biotin --prot ...

  8. GenBank blastx search result: AK061906 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK061906 001-041-H10 AF042099.1 Sulfolobus metallicus putative carboxyl transferase (pccB), biotin ... in carboxylase (accC), and biotin ... carboxyl carrier protein (accB) genes, complete cd ...

  9. GenBank blastx search result: AK060716 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060716 001-031-D11 AF042099.1 Sulfolobus metallicus putative carboxyl transferase (pccB), biotin ... in carboxylase (accC), and biotin ... carboxyl carrier protein (accB) genes, complete cd ...

  10. Abscisic acid as a factor in regulation of photosynthetic carbon metabolism of pea seedlings

    Directory of Open Access Journals (Sweden)

    Maria Faltynowicz

    2014-02-01

    Full Text Available The influence of abscisic acid (ABA on carbon metabolism and the activity of ribulosebisphosphate (RuBP and phosphoenolpyruvate (PEP carboxylases in 8-day-old pea seedlings was investigated. It was endeavoured to correlate the changes observed in metabolic processes with the endogenous ABA level. In plants treated with ABA incorporation of labeled carbon into sucrose, glucose, fructose and sugar phosphates was depressed, while 14C incorporation into starch, ribulose and malic acid was enhanced. The activity of RuBP carboxylase was considerably lowered, whereas that of PEP carboxylase was slightly increased. It is considered that inhibition of photosynthesis due to the action of ABA is caused to a great extent by the obstruction of the C-3 pathway and reduced activity of RuBP carboxylase, whereas (β-carboxylation was not blocked.

  11. Bacterial Hydrolysis of Protein and Methylated Protein and Its Implications for Studies of Protein Degradation in Aquatic Systems

    OpenAIRE

    Keil, Richard G.; Kirchman, David L.

    1992-01-01

    Ribulose 1,5-bisphosphate carboxylase was radiolabelled by in vitro translation, resulting in uniformly labelled ribulose 1,5-bisphosphate carboxylase, and also by reductive methylation. We investigated the degradation of the two forms of radiolabelled protein by natural bacterial populations. Although total hydrolysis of uniformly labelled protein and methylated protein was nearly equal, percent assimilation, respiration, and release as low-molecular-weight material were different. Radioacti...

  12. Contribution of carbon fixed by Rubisco and PEPC to phloem export in the Crassulacean acid metabolism plant Kalanchoë daigremontiana

    OpenAIRE

    Wild, Birgit; Wanek, Wolfgang; Postl, Wolfgang; Richter, Andreas

    2010-01-01

    Crassulacean acid metabolism (CAM) plants exhibit a complex interplay between CO2 fixation by phosphoenolpyruvate carboxylase (PEPC) and ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), and carbon demand for CAM maintenance and growth. This study investigated the flux of carbon from PEPC and direct Rubisco fixation to different leaf carbon pools and to phloem sap over the diurnal cycle. Concentrations and carbon isotope compositions of starch, soluble sugars, and organic acids were ...

  13. Oxygen requirement and inhibition of C4 photosynthesis

    OpenAIRE

    Maroco, João; Ku, Maurice S. B.; Peter J. Lea; Dever, Louisa V.; Leegood, Richard C.; Furbank, Robert T.; Edwards, Gerald E.

    1998-01-01

    The basis for O2 sensitivity of C4 photosynthesis was evaluated using a C4-cycle-limited mutant of Amaranthus edulis (a phosphoenolpyruvate carboxylase-deficient mutant), and a C3-cyclelimited transformant of Flaveria bidentis (an antisense ribulose-1,5- bisphosphate carboxylase/oxygenase [Rubisco] small subunit transformant). Data obtained with the C4-cycle-limited mutant showed that atmospheric levels of O2 (20 kPa) caused increased inhibition of photosynthesis as a res...

  14. Biotin Deficiency Reduces Expression of SLC19A3, a Potential Biotin Transporter, in Leukocytes from Human Blood12

    OpenAIRE

    Vlasova, Tatyana I; Stratton, Shawna L.; Wells, Amanda M.; Mock, Nell I.; Mock, Donald M.

    2005-01-01

    In evaluating potential indicators of biotin status, we quantitated the expression of biotin-related genes in leukocytes from human blood of normal subjects before and after inducing marginal biotin deficiency. Biotin deficiency was induced experimentally by feeding an egg-white diet for 28 d. Gene expression was quantitated for the following biotin-related proteins: methylcrotonyl-CoA carboxylase chains A (MCCA) and B (MCCB); propionyl-CoA carboxylase chains A (PCCA) and B (PCCB); pyruvate c...

  15. AcEST: BP912817 [AcEST

    Lifescience Database Archive (English)

    Full Text Available YMU001_000023_C02 513 Adiantum capillus-veneris mRNA. clone: YMU001_000023_C02. BP912817 - Show ... t sp_hit_id Q06862 Definition sp|Q06862|ACCC_ANASP Biotin ... carboxylase OS=Anabaena sp. (strain PCC 7120) Alig ... cant alignments: (bits) Value sp|Q06862|ACCC_ANASP Biotin ... carboxylase OS=Anabaena sp. (strain ... 245 8e-65 ...

  16. Marginal Biotin Deficiency is Common in Normal Human Pregnancy and Is Highly Teratogenic in Mice1–3

    OpenAIRE

    Mock, Donald M.

    2009-01-01

    In studies of marginal biotin deficiency induced experimentally in adults, increased urinary excretion of 3-hydroxyisovaleric acid (3HIA), which likely reflects decreased activity of the biotin-dependent enzyme β-methylcrotonyl-CoA carboxylase, and decreased activity of the biotin-dependent enzyme propionyl-CoA carboxylase (PCC) in peripheral blood lymphocytes have been validated as indices of biotin status. About half of pregnant women excrete increased amounts of urinary 3HIA. However, inte...

  17. Biotin requirements for DNA damage prevention

    OpenAIRE

    Zempleni, Janos; Teixeira, Daniel Camara; Kuroishi, Toshinobu; Cordonier, Elizabeth L; Baier, Scott

    2011-01-01

    Biotin serves as a covalently bound coenzyme in five human carboxylases; biotin is also attached to histones H2A, H3, and H4, although the abundance of biotinylated histones is low. Biotinylation of both carboxylases and histones is catalyzed by holocarboxylase synthetase. Human biotin requirements are unknown. Recommendations for adequate intake of biotin are based on the typical intake of biotin in an apparently healthy population, which is only a crude estimate of the true intake due to an...

  18. On the intermediacy of carboxyphosphate in biotin-dependent carboxylations

    International Nuclear Information System (INIS)

    In the ATP-dependent carboxylation of biotin that is catalyzed by most biotin-dependent carboxylases, a fundamental mechanistic question is whether the ATP activates bicarbonate (via the formation of carboxyphosphate as an intermediate) or whether the ATP activates biotin (via the formation of O-phosphobiotin). The authors have resorted to three mechanistic tests using the biotin carboxylase subunit of acetyl-CoA carboxylase from Escherichia coli: positional isotope exchange, intermediate trapping, and 18O tracer experiments on the ATPase activity. First, no catalysis of positional isotope exchange in adenosine 5'-([α,β-18O,β,β-18O2]triphosphate) was observed when either biotin or bicarbonate was absent, nor was any exchange seen in the presence of both N-1-methylbiotin and bicarbonate. Second, the putative carboxyphosphate intermediate could not be trapped as its trimethyl ester, under conditions of incubation and analysis where the authentic triester was shown to be adequately stable. In the third test, however, they showed that the ATPase activity of biotin carboxylase that is seen in the absence of biotin, an activity that is known to parallel the normal carboxylase reaction when biotin is present, occurs with the transfer of an 18O label directly from [18O]bicarbonate into the product Pi. This result suggests that the bicarbonate-dependent biotin-independent ATPase reaction catalyzed by biotin carboxylase goes via carboxyphosphate and that the carboxylation of biotin itself may proceed analogously

  19. Photorespiration and carbon concentrating mechanisms: two adaptations to high O2, low CO2 conditions.

    Science.gov (United States)

    Moroney, James V; Jungnick, Nadine; Dimario, Robert J; Longstreth, David J

    2013-11-01

    This review presents an overview of the two ways that cyanobacteria, algae, and plants have adapted to high O2 and low CO2 concentrations in the environment. First, the process of photorespiration enables photosynthetic organisms to recycle phosphoglycolate formed by the oxygenase reaction catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Second, there are a number of carbon concentrating mechanisms that increase the CO2 concentration around Rubisco which increases the carboxylase reaction enhancing CO2 fixation. This review also presents possibilities for the beneficial modification of these processes with the goal of improving future crop yields. PMID:23771683

  20. Oxygen Requirement and Inhibition of C4 Photosynthesis . An Analysis of C4 Plants Deficient in the C3 and C4 Cycles

    OpenAIRE

    Maroco, J.P.; Ku, M.S.B.; Lea, P J; Dever, L.V.; Leegood, R C; Furbank, R.T.; Edwards, G. E.

    1998-01-01

    The basis for O2 sensitivity of C4 photosynthesis was evaluated using a C4-cycle-limited mutant of Amaranthus edulis (a phosphoenolpyruvate carboxylase-deficient mutant), and a C3-cycle-limited transformant of Flaveria bidentis (an antisense ribulose-1,5-bisphosphate carboxylase/oxygenase [Rubisco] small subunit transformant). Data obtained with the C4-cycle-limited mutant showed that atmospheric levels of O2 (20 kPa) caused increased inhibition of photosynthesis as a result of higher levels ...

  1. Intake and Urinary Amounts of Biotin in Japanese Elementary School Children, College Students, and Elderly Persons

    OpenAIRE

    Katsumi Shibata; Tomiko Tsuji; Tsutomu Fukuwatari

    2013-01-01

    Biotin enzymes such as pyruvate carboxylase and acetyl-CoA carboxylase are involved with the most basic metabolism. Thus, it is very important to monitor the biotin nutritional status for maintaining good health. We examined urinary excretion and the intake of biotin in a Japanese sample population of 60 boys and 36 girls (10–12 y), 37 male and 135 female college students (18–27 y), and 35 female elderly persons (70–84 y) living freely. All food consumed, and the corresponding weighing, for 4...

  2. Characterization of the biotin uptake system encoded by the biotin-inducible bioYMN operon of Corynebacterium glutamicum

    OpenAIRE

    Schneider Jens; Peters-Wendisch Petra; Stansen K Corinna; Götker Susanne; Maximow Stanislav; Krämer Reinhard; Wendisch Volker F

    2012-01-01

    Abstract Background The amino acid-producing Gram-positive Corynebacterium glutamicum is auxotrophic for biotin although biotin ring assembly starting from the precursor pimeloyl-CoA is still functional. It possesses AccBC, the α-subunit of the acyl-carboxylases involved in fatty acid and mycolic acid synthesis, and pyruvate carboxylase as the only biotin-containing proteins. Comparative genome analyses suggested that the putative transport system BioYMN encoded by cg2147, cg2148 and cg2149 m...

  3. Dicty_cDB: SFE842 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available icant alignments: (bits) Value N U23210 |U23210.1 Debaryomyces occidentalis phosphoribosylaminoimidazole carboxyla...haliana clone U50031 putative phosphoribosylaminoimidazole carboxylase (At2g37690) mRNA, complete cds. 76 1e...se, complete cds. 56 3e-07 3 AF349948 |AF349948.1 Nicotiana tabacum phosphoribosylaminoimidazole carboxyla...se (AIRC) mRNA, partial cds. 66 1e-06 1 AY429422 |AY429422.1 Nicotiana tabacum phosphoribosylaminoimidazole carboxyla...inii ADE2 gene for phosphoribosyl-5-aminoimidazole carboxyla

  4. Regulation of carbon dioxide fixation in facultatively autotrophic bacteria. A phisiological and genetical study.

    NARCIS (Netherlands)

    Meijer, Wilhelmus Gerhardus

    1990-01-01

    Autotrophic bactcria are capable of CO2 fixation via the Calvin cycle, emplofng energy derived from the oxidation of anorganic substrates (e.g. Hz), simple organic substrates (one-carbon compounds, e.g. methanol, formate), or from light. Ribulose-1,5-bisphospbate carboxylase/oxygenase (RuBisC/O), pb

  5. Growth at elevated CO2 delays the adverse effects of drought stress on leaf photosynthesis of the C4 sugarcane

    Science.gov (United States)

    Sugarcane was grown in sunlit greenhouses at 360 and 720 ppm CO2, and drought was imposed for 13 days on 4-month old plants. Leaf CO2 exchange rate (CER) and activity of Rubisco were marginally affected by high CO2 but were reduced by drought, whereas activity of PEP carboxylase was reduced by high ...

  6. GenBank blastx search result: AK288054 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288054 J075152E14 DQ088087.1 DQ088087 Musa x paradisiaca clone S1 genotype AAAB chloroplast ri ... hosphate carboxylase/oxygenase small subunit (rbcS-Ma1 ) gene, partial cds; nuclear gene for chloroplast p ...

  7. GenBank blastx search result: AK288054 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288054 J075152E14 DQ088099.1 DQ088099 Musa acuminata genotype AAA chloroplast ribulose-1,5-bis ... hosphate carboxylase/oxygenase small subunit (rbcS-Ma1 ) gene, complete cds; nuclear gene for chloroplast ...

  8. GenBank blastx search result: AK288517 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288517 J090043B03 DQ088099.1 DQ088099 Musa acuminata genotype AAA chloroplast ribulose-1,5-bis ... hosphate carboxylase/oxygenase small subunit (rbcS-Ma1 ) gene, complete cds; nuclear gene for chloroplast ...

  9. GenBank blastx search result: AK288517 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288517 J090043B03 DQ088087.1 DQ088087 Musa x paradisiaca clone S1 genotype AAAB chloroplast ri ... hosphate carboxylase/oxygenase small subunit (rbcS-Ma1 ) gene, partial cds; nuclear gene for chloroplast p ...

  10. Regulation of Autotrophic and Heterotrophic Metabolism in Pseudomonas oxalaticus OX1. Growth on Fructose and on Mixtures of Fructose and Formate in Batch and Continuous Cultures

    NARCIS (Netherlands)

    Dijkhuizen, L.; Harder, W.

    1984-01-01

    In Pseudomonas oxalaticus the synthesis of enzymes involved in autotrophic CO2 fixation via the Calvin cycle is regulated by repression/derepression. During growth of the organism on fructose alone, the synthesis of ribulosebisphosphate carboxylase (RuBPCase) remained fully repressed, both in batch

  11. GenBank blastn search result: AK109734 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK109734 002-146-C06 AJ279036.1 Cynodon dactylon (L.) Pers. partial mRNA for putative C4 ... phospho ... enolpyruvate carboxylase (c4 ... PEPCase gene).|PLN PLN 3e-50 Plus Minus ...

  12. Enhancement in leaf photosynthesis and upregulation of rubisco in the C4 sorghum plant at elevated growth carbon dioxide and temperature occur at early stages of leaf ontogeny.

    Science.gov (United States)

    Grain sorghum was grown at 350 and 700 (high) ppm CO2, and at daytime maximum/nighttime minimum temperatures of 30/20 and 36/26C. Gas exchange rates, activities of Rubisco and PEP carboxylase (PEPC), leaf area, and biomass of various plant components were determined at different stages of leaf and p...

  13. Sequence Classification: 735847 [TMBETA-GENOME[Archive

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|51597302|ref|YP_071493.1| acetyl-coenzyme A ... carboxylase carboxyl transferase subunit al ... || http://www.ncbi.nlm.nih.gov/protein/51597302 ...

  14. Compassionate Use of Triheptanoin (C7) for Inherited Disorders of Energy Metabolism

    Science.gov (United States)

    2016-09-12

    Very Long-chain acylCoA Dehydrogenase (VLCAD) Deficiency; Carnitine Palmitoyltransferase Deficiencies (CPT1, CPT2); Mitochondrial Trifunctional Protein Deficiency; Long-chain Hydroxyacyl-CoA Dehydrogenase Deficiency; Glycogen Storage Disorders; Pyruvate Carboxylase Deficiency Disease; ACYL-CoA DEHYDROGENASE FAMILY, MEMBER 9, DEFICIENCY of; Barth Syndrome

  15. Oxygen-18 incorporation into malic acid during nocturnal carbon dioxide fixation in crassulacean acid metabolism plants: a new approach to estimating in vivo carbonic anhydrase activity

    Energy Technology Data Exchange (ETDEWEB)

    Holtum, J.A.M.; Summons, R.; Roeske, C.A.; Comins, H.N.; O' Leary, M.H.

    1984-01-01

    Crassulacean acid metabolism (CAM) plants fix carbon dioxide at night by the carboxylation of phosphoenolpyruvate. If CO2 fixation is conducted with TC YO2, then in the absence of carbonic anhydrase, the malate formed by dark CO2 fixation should also contain high levels of carbon-13 and oxygen-18. Conversely, if carbonic anhydrase is present and highly active, oxygen exchange between CO2 and cellular H2O will occur more rapidly than carboxylation, and the ( TC) malate formed will contain little or no oxygen-18 above the natural abundance level. The presence of oxygen-18 in these molecules can be detected either by nuclear magnetic resonance or by mass spectrometry. Studies of phosphoenolpyruvate carboxylase in the presence and absence of carbonic anhydrase in vitro confirm the validity of the method. When CAM plants are studied by this method, we find that most species show incorporation of a significant amount of oxygen-18. Comparison of these results with results of isotope fractionation and gas exchange studies permits calculation of the in vivo activity of carbonic anhydrase toward HCO3 compared with that of phosphoenolpyruvate carboxylase. The ratio (carbonic anhydrase activity/phosphoenolpyruvate carboxylase activity) is species dependent and varies from a low of about 7 for Ananas comosus to values near 20 for Hoya carnosa and Bryophyllum pinnatum, 40 for Kalanchoee daigremontiana, and 100 or greater for Bryophyllum tubiflorum, Kalanchoee serrata, and Kalanchoae tomentosa. Carbonic anhydrase activity increases relative to phosphoenolpyruvate carboxylase activity at higher temperature. 37 references, 2 figures, 8 tables.

  16. Fatty acid biosynthesis. VIII. The fate of malonyl-CoA in fatty acid biosynthesis by purified enzymes from lactating-rabbit mammary gland

    DEFF Research Database (Denmark)

    Hansen, Heinz Johs. Max; Carey, E.M.; Dils, R.

    1971-01-01

    - 1. We have investigated the formation and utilization of malonyl-CoA in fatty acid synthesis catalysed by preparations of partially purified acetyl-CoA carboxylase and purified fatty acid synthetase from lactating-rabbit mammary gland. - 2. Carboxylation of [1-14C]acetyl-CoA was linked to fatty...

  17. Bibliography of reviews and methods of photosynthesis-90

    Czech Academy of Sciences Publication Activity Database

    Šesták, Zdeněk; Čatský, Jiří

    2006-01-01

    Roč. 44, č. 4 (2006), s. 627-640. ISSN 0300-3604 Institutional research plan: CEZ:AV0Z50380511 Keywords : phosphoenolpyruvate carboxylase * water use efficiency * transpiration Subject RIV: ED - Physiology Impact factor: 0.782, year: 2006

  18. Discoveries in Rubisco: a historical perspective

    Science.gov (United States)

    Historic discoveries and key observations related to Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase), from 1947 to 2006, are presented. Currently, around 200 papers describing Rubisco research are published each year and the literature contains more than 5000 manuscripts on the subject. Wh...

  19. Sequence Classification: 389949 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|31794460|ref|NP_856953.1| PROBABLE PROPIONYL-COA CARB...OXYLASE BETA CHAIN 5 ACCD5 (PCCASE) (PROPANOYL-COA:CARBON DIOXIDE LIGASE) || http://www.ncbi.nlm.nih.gov/protein/31794460 ...

  20. Sequence Classification: 182868 [

    Lifescience Database Archive (English)

    Full Text Available TMB Non-TMH Non-TMB TMB Non-TMB Non-TMB >gi|17987345|ref|NP_539979.1| BIOTIN CARBOX...YL CARRIER PROTEIN OF ACETYL-COA CARBOXYLASE || http://www.ncbi.nlm.nih.gov/protein/17987345 ...

  1. Sequence Classification: 511437 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|17546699|ref|NP_520101.1| PROBABLE ACETYL-COENZYME A CAR...BOXYLASE CARBOXYL TRANSFERASE (SUBUNIT BETA) PROTEIN || http://www.ncbi.nlm.nih.gov/protein/17546699 ...

  2. Sequence Classification: 397300 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|15608044|ref|NP_215419.1| PUTATIVE ACETYL-COENZYME A CAR...BOXYLASE CARBOXYL TRANSFERASE (SUBUNIT BETA) ACCD3 (ACCASE BETA CHAIN) || http://www.ncbi.nlm.nih.gov/protein/15608044 ...

  3. Sequence Classification: 565760 [

    Lifescience Database Archive (English)

    Full Text Available TMB Non-TMH Non-TMB TMB Non-TMB Non-TMB >gi|15965073|ref|NP_385426.1| PROBABLE BIOTIN CARB...OXYL CARRIER PROTEIN OF ACETYL-COA CARBOXYLASE (BCCP) || http://www.ncbi.nlm.nih.gov/protein/15965073 ...

  4. Sequence Classification: 183826 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|17988303|ref|NP_540937.1| ACETYL-COENZYME A CARB...OXYLASE CARBOXYL TRANSFERASE SUBUNIT BETA || http://www.ncbi.nlm.nih.gov/protein/17988303 ...

  5. Sequence Classification: 564470 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|15963783|ref|NP_384136.1| PROBABLE ACETYL-COENZYME A CAR...BOXYLASE CARBOXYL TRANSFERASE SUBUNIT BETA PROTEIN || http://www.ncbi.nlm.nih.gov/protein/15963783 ...

  6. Sequence Classification: 567122 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|15966435|ref|NP_386788.1| PROBABLE ACETYL-COENZYME A CAR...BOXYLASE CARBOXYL TRANSFERASE SUBUNIT ALPHA PROTEIN || http://www.ncbi.nlm.nih.gov/protein/15966435 ...

  7. Sequence Classification: 510626 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|17545888|ref|NP_519290.1| PROBABLE ACETYL-COENZYME A CAR...BOXYLASE CARBOXYL TRANSFERASE (ALPHA SUBUNIT) PROTEIN || http://www.ncbi.nlm.nih.gov/protein/17545888 ...

  8. Sequence Classification: 512243 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|17547505|ref|NP_520907.1| PROBABLE BIOTIN CARB...OXYL CARRIER PROTEIN OF ACETYL-COA CARBOXYLASE (BCCP) || http://www.ncbi.nlm.nih.gov/protein/17547505 ...

  9. Sequence Classification: 387581 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|31792092|ref|NP_854585.1| PUTATIVE ACETYL-COENZYME A CAR...BOXYLASE CARBOXYL TRANSFERASE (SUBUNIT BETA) ACCD3 (ACCASE BETA CHAIN) || http://www.ncbi.nlm.nih.gov/protein/31792092 ...

  10. Sequence Classification: 390462 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|31794973|ref|NP_857466.1| PROBABLE PROPIONYL-COA CARB...OXYLASE BETA CHAIN 4 ACCD4 (PCCASE) (PROPANOYL-COA:CARBON DIOXIDE LIGASE) || http://www.ncbi.nlm.nih.gov/protein/31794973 ...

  11. Sequence Classification: 400246 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|57117158|ref|NP_218316.2| PROBABLE PROPIONYL-CoA CARB...OXYLASE BETA CHAIN 4 ACCD4 (PCCASE) (PROPANOYL-COA:CARBON DIOXIDE LIGASE) || http://www.ncbi.nlm.nih.gov/protein/57117158 ...

  12. Sequence Classification: 244729 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|62389589|ref|YP_224991.1| BIOTIN CARB...OXYLASE AND BIOTIN CARBOXYL CARRIER PROTEIN || http://www.ncbi.nlm.nih.gov/protein/62389589 ...

  13. Sequence Classification: 399719 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|15610416|ref|NP_217797.1| PROBABLE PROPIONYL-CoA CARB...OXYLASE BETA CHAIN 5 ACCD5 (PCCASE) (PROPANOYL-COA:CARBON DIOXIDE LIGASE) || http://www.ncbi.nlm.nih.gov/protein/15610416 ...

  14. Sequence Classification: 697789 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|34557455|ref|NP_907270.1| PUTATIVE BIOTIN CARB...OXYL CARRIER PROTEIN OF ACETYL-COA CARBOXYLASE || http://www.ncbi.nlm.nih.gov/protein/34557455 ...

  15. Sequence Classification: 181846 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|17986323|ref|NP_538957.1| ACETYL-COENZYME A CARB...OXYLASE CARBOXYL TRANSFERASE SUBUNIT ALPHA || http://www.ncbi.nlm.nih.gov/protein/17986323 ...

  16. Unlocking the Barley Genome by Chromosomal and Comparative Genomics

    Czech Academy of Sciences Publication Activity Database

    Mayer, K. F. X.; Martis, M.; Hedley, P. E.; Šimková, Hana; Liu, H.; Morris, J. A.; Steuernagel, B.; Taudien, S.; Kubaláková, Marie; Suchánková, Pavla; Doležel, Jaroslav; Stein, N.

    Roč. 23, č. 4 ( 2011 ), s. 1249-1263. ISSN 1040-4651 Institutional research plan: CEZ:AV0Z50380511 Keywords : PSEUDO-RESPONSE-REGULATOR * ACETYL-COA CARBOXYLASE * TRITICUM-AESTIVUM L. Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 8.987, year: 2011

  17. Drug: D03158 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D03158 Drug Brocresine (USAN/INN) C7H8BrNO2 216.9738 218.0479 D03158.gif Inhibitor [histidine ... de ... carboxylase] histidine ... decarboxylase inhibitor [HSA:3067] [KO:K01590] hsa ... 00340(3067) Histidine ... metabolism Target-based classification of drugs [B ...

  18. Sequence Classification: 889519 [

    Lifescience Database Archive (English)

    Full Text Available Non-TMB Non-TMH Non-TMB Non-TMB Non-TMB Non-TMB >gi|6319685|ref|NP_009767.1| Urea ... amidolyase, co ... ntains both urea ... carboxylase and allophanate hydrolase activities, ... degrades urea ... to CO2 and NH3; expression sensitive to nitrogen c ...

  19. Unlocking the Barley Genome by Chromosomal and Comparative Genomics

    Czech Academy of Sciences Publication Activity Database

    Mayer, K. F. X.; Martis, M.; Hedley, P. E.; Šimková, Hana; Liu, H.; Morris, J. A.; Steuernagel, B.; Taudien, S.; Kubaláková, Marie; Suchánková, Pavla; Doležel, Jaroslav; Stein, N.

    2011-01-01

    Roč. 23, č. 4 (2011), s. 1249-1263. ISSN 1040-4651 Institutional research plan: CEZ:AV0Z50380511 Keywords : PSEUDO-RESPONSE-REGULATOR * ACETYL-COA CARBOXYLASE * TRITICUM-AESTIVUM L. Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 8.987, year: 2011

  20. GenBank blastx search result: AK062203 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK062203 001-046-G09 AF497098.1 Amorphophallus smithsonianus ribulose-1,5-bisphosph...ate carboxylase/oxygenase large subunit (rbcL) gene, partial cds; chloroplast gene for chloroplast product.|PLN PLN 4e-86 +3 ...

  1. Arabidopsis CDS blastp result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 At1g37150.4 68414.m04644 holocarboxylase synthetase 2 (HCS2.d) identical to ... eptor splice sites; contains Pfam profile PF03099: Biotin /lipoate A/B protein ligase family; contains TIGRfa ... m profile TIGR00121: biotin --acetyl-CoA-carboxylase ligase; 6e-97 ...

  2. SwissProt search result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 (P46363) BirA bifunctional protein [Includes: Biotin ... operon repressor; Biotin ... [acetyl-CoA-carboxylase] synthetase (EC 6.3.4.15) (Biotin --protein ligase)] BIRA_HAEIN 1e-16 ...

  3. Arabidopsis CDS blastp result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 At1g37150.1 68414.m04641 holocarboxylase synthetase 2 (HCS2.d) identical to ... eptor splice sites; contains Pfam profile PF03099: Biotin /lipoate A/B protein ligase family; contains TIGRfa ... m profile TIGR00121: biotin --acetyl-CoA-carboxylase ligase; 1e-72 ...

  4. SwissProt search result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 (P50747) Biotin --protein ligase (EC 6.3.4.-) (Biotin ... apo-protein ligase) [In ... cludes: Biotin --[methylmalonyl-CoA-carboxytransferase] ligase (EC ... 6.3.4.9); Biotin --[propionyl-CoA-carboxylase [ATP-hydrolyzing

  5. Arabidopsis CDS blastp result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 At1g37150.3 68414.m04643 holocarboxylase synthetase 2 (HCS2.d) identical to ... eptor splice sites; contains Pfam profile PF03099: Biotin /lipoate A/B protein ligase family; contains TIGRfa ... m profile TIGR00121: biotin --acetyl-CoA-carboxylase ligase; 4e-82 ...

  6. SwissProt search result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 (P42975) BirA bifunctional protein [Includes: Biotin ... operon repressor; Biotin ... [acetyl-CoA-carboxylase] synthetase (EC 6.3.4.15) (Biotin --protein ligase)] BIRA_BACSU 9e-11 ...

  7. Gene : CBRC-XTRO-01-0052 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0052 Novel UN D UNKNOWN BCCA_MYCLE 1e-141 55% ref|YP_296657.1| Biotin /lipoyl attach ... amoyl-phosphate synthetase large chain, N-terminal:Biotin ... carboxylase, C-terminal [Ralstonia eutropha JMP134 ... ] gb|AAZ61813.1| Biotin /lipoyl attachment:Carbamoyl-phosphate synthase L c ...

  8. GenBank blastx search result: AK061906 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK061906 001-041-H10 AF317651.1 Methanosarcina barkeri pyruvate carboxylase biotin -containing su ... ATP-binding subunit PYCA (pycA), and bifunctional biotin ... ligase/biotin ... operon repressor PYCB (birA) genes, ...

  9. NCBI nr-aa BLAST: CBRC-XTRO-01-0052 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0052 ref|YP_296657.1| Biotin /lipoyl attachment:Carbamoyl-phosphate synthase L chain ... amoyl-phosphate synthetase large chain, N-terminal:Biotin ... carboxylase, C-terminal [Ralstonia eutropha JMP134 ... ] gb|AAZ61813.1| Biotin /lipoyl attachment:Carbamoyl-phosphate synthase L c ...

  10. NCBI nr-aa BLAST: CBRC-XTRO-01-0052 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-XTRO-01-0052 ref|YP_233608.1| Biotin /lipoyl attachment:Carbamoyl-phosphate synthase L chain ... amoyl-phosphate synthetase large chain, N-terminal:Biotin ... carboxylase, C-terminal [Pseudomonas syringae pv. ... syringae B728a] gb|AAY35570.1| Biotin /lipoyl attachment:Carbamoyl-phosphate synthase L c ...

  11. SwissProt search result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 (Q920N2) Biotin --protein ligase (EC 6.3.4.-) (Biotin ... apo-protein ligase) [In ... cludes: Biotin --[methylmalonyl-CoA-carboxytransferase] ligase (EC ... 6.3.4.9); Biotin --[propionyl-CoA-carboxylase [ATP-hydrolyzing

  12. Arabidopsis CDS blastp result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 At1g37150.2 68414.m04642 holocarboxylase synthetase 2 (HCS2.d) identical to ... eptor splice sites; contains Pfam profile PF03099: Biotin /lipoate A/B protein ligase family; contains TIGRfa ... m profile TIGR00121: biotin --acetyl-CoA-carboxylase ligase; 1e-100 ...

  13. SwissProt search result: AK243419 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243419 J100066K03 (P48445) Biotin --protein ligase (EC 6.3.4.-) (Biotin ... Apo-protein ligase) [In ... cludes: Biotin --[methylmalonyl-CoA-carboxytransferase] ligase (EC ... 6.3.4.9); Biotin --[propionyl-CoA-carboxylase [ATP-hydrolyzing

  14. Dietary vitamin K and therapeutic warfarin alter susceptibility to vascular calcification in experimental chronic kidney disease

    Science.gov (United States)

    The leading cause of death in patients with chronic kidney disease (CKD) is cardiovascular disease (CVD), with vascular calcification (VC) being a key modifier of disease progression. A local regulator of vascular calcification is vitamin K. This gamma-glutamyl carboxylase substrate is an essential ...

  15. Mitochondrial Carbonic Anhydrase VA Deficiency Resulting from CA5A Alterations Presents with Hyperammonemia in Early Childhood

    Science.gov (United States)

    van Karnebeek, Clara D.; Sly, William S.; Ross, Colin J.; Salvarinova, Ramona; Yaplito-Lee, Joy; Santra, Saikat; Shyr, Casper; Horvath, Gabriella A.; Eydoux, Patrice; Lehman, Anna M.; Bernard, Virginie; Newlove, Theresa; Ukpeh, Henry; Chakrapani, Anupam; Preece, Mary Anne; Ball, Sarah; Pitt, James; Vallance, Hilary D.; Coulter-Mackie, Marion; Nguyen, Hien; Zhang, Lin-Hua; Bhavsar, Amit P.; Sinclair, Graham; Waheed, Abdul; Wasserman, Wyeth W.; Stockler-Ipsiroglu, Sylvia

    2014-01-01

    Four children in three unrelated families (one consanguineous) presented with lethargy, hyperlactatemia, and hyperammonemia of unexplained origin during the neonatal period and early childhood. We identified and validated three different CA5A alterations, including a homozygous missense mutation (c.697T>C) in two siblings, a homozygous splice site mutation (c.555G>A) leading to skipping of exon 4, and a homozygous 4 kb deletion of exon 6. The deleterious nature of the homozygous mutation c.697T>C (p.Ser233Pro) was demonstrated by reduced enzymatic activity and increased temperature sensitivity. Carbonic anhydrase VA (CA-VA) was absent in liver in the child with the homozygous exon 6 deletion. The metabolite profiles in the affected individuals fit CA-VA deficiency, showing evidence of impaired provision of bicarbonate to the four enzymes that participate in key pathways in intermediary metabolism: carbamoylphosphate synthetase 1 (urea cycle), pyruvate carboxylase (anaplerosis, gluconeogenesis), propionyl-CoA carboxylase, and 3-methylcrotonyl-CoA carboxylase (branched chain amino acids catabolism). In the three children who were administered carglumic acid, hyperammonemia resolved. CA-VA deficiency should therefore be added to urea cycle defects, organic acidurias, and pyruvate carboxylase deficiency as a treatable condition in the differential diagnosis of hyperammonemia in the neonate and young child. PMID:24530203

  16. Protein (Viridiplantae): 356565438 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 4:8744 3398:8744 71240:7447 91827:7447 71275:86 91835:8936 72025:9373 3803:9373 3814:9373 163735:3613 3846:3613 3847:3613 PREDICTED...: phosphoenolpyruvate carboxylase 1-like, partial Glycine max KGYMESSKPAVELVKFKPTSDYAPGMEDTRILTMKGIVVGMQNTG ...

  17. Molecular cloning and expression profile of ß-ketoacyl-acp synthase gene from tung tree (Vernicia fordii Hemsl.)

    Science.gov (United States)

    Tung tree (Vernicia fordii) is an important woody oil tree. Tung tree seeds contain 50-60% oil with approximately 80 mole a-eleostearic acid (9cis, 11trans, 13trans octadecatrienoic acid). Fatty acid synthesis is catalyzed by the concerted action of acetyl-CoA carboxylase and fatty acid synthase, a ...

  18. Photorespiration.

    Science.gov (United States)

    Rao, K. K.; Hall, D. O.

    1982-01-01

    Topics in this discussion of photorespiration (light-dependent oxygen consumption and carbon dioxide evolution from leaves) include: (1) the biochemistry of photorespiration; (2) ribulose biphosphate carboxylase and glycollate synthesis; (3) metabolism of glycollate; (4) plants lacking photorespiratory systems; and (5) advantages of…

  19. Bibliography of reviews and methods of photosynthesis — 89

    Czech Academy of Sciences Publication Activity Database

    Šesták, Zdeněk; Čatský, Jiří

    2005-01-01

    Roč. 43, č. 4 (2005), s. 621-640. ISSN 0300-3604 R&D Projects: GA MŠk LN00A081 Institutional research plan: CEZ:AV0Z50380511 Keywords : phosphoenolpyruvate carboxylase * photosynthetically active radiation * transpiration Subject RIV: EF - Botanics Impact factor: 0.810, year: 2005

  20. Exercise-induced regulation of key factors in substrate choice and gluconeogenesis in mouse liver

    DEFF Research Database (Denmark)

    Knudsen, Jakob Grunnet; Biensø, Rasmus Sjørup; Hassing, Helle Adser;

    2015-01-01

    As the demand for hepatic glucose production increases during exercise, regulation of liver substrate choice and gluconeogenic activity becomes essential. The aim of the present study was to investigate the effect of a single exercise bout on gluconeogenic protein content and regulation of enzymes...... involved in substrate utilization in the liver. Mice were subjected to 1 h of treadmill exercise, and livers were removed immediately, 4 or 10 h after exercise. Glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxylase (PEPCK) mRNA contents in the liver increased immediately after exercise, while...... the PEPCK protein content increased at 10 h of recovery. Furthermore, 5′AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), and pyruvate dehydrogenase (PDH)-E1α Ser293 phosphorylations decreased immediately after exercise. In addition, PDH kinase 4 (PDK4) mRNA and protein content increased...

  1. Differential responses of photosynthetic parameters of pigeonpea and amaranth leaf discs to SO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Saraswathi, J.; Rao, K.V.M. [Andhra University, Visakhapatnam (India). Dept. of Botany

    1995-08-01

    The reduction in chlorophyll (Chl) and protein contents and the increase in amino acid content in leaf discs in response to aqueous SO{sub 2} exposure under continuous irradiance were more expressed in Amaranthus paniculatus (C-4 plant) than in Cajantus cajan (C-3 plant). The content of SH-compounds increased more in pigenonpea than in amaranth leaf discs in response to SO{sub 2}. Aqueous SO{sub 2} exposure also reduced the CO{sub 2} fixation and ribulose-1,5-bisphosphate carboxylase (RuBPC) and phosphoenolpyruvate carboxylase (PEPC) activities in leaf discs of both plant species. The differences in sensitivity of these plants to SO{sub 2} were related to their conversion efficiency of SO{sub 2} to less toxic substances and sulphydryl compounds.

  2. Effect of abscisic acid and blue radiation on photosynthesis and growth of pea plants

    International Nuclear Information System (INIS)

    The effect of abscisic acid (ABA) on the net photosynthetic rate (PN), the ribulose 1,5-bisphosphate carboxylase (RuBPC) and the phosphoenolpyruvate carboxylase (PEPC) activities, the chlorophyll (Chl) content and growth of pea plants (Pisum sativum) grown under ''white'' (WR) or blue radiation (BR), were investigated. BR as compared to WR enhanced PN, the activities of examined enzymes, and Chl content. In spite of higher PN of the plants grown under BR, dry matter of their shoots was lower in comparison with WR. ABA-treated plants grown under both WR and BR showed reduction in PN. ABA had no effect on the activities of both RuBPC and PEPC and the Chl content. Independent on the radiation quality, ABA reduced stem elongation, but did not affect the biomass of whole shoots

  3. Effect of sodium chloride on photosynthetic 14CO2 assimilation in Portulaca oleracea Linn

    International Nuclear Information System (INIS)

    Effect of NaCl on ion uptake, photosynthetic rate and photosynthetic products in a C4 non-CAM succulent, P. oleracea has been investigated. NaCl causes accumulation of Na as well as Cl ions with decrease in K and Ca contents. Chlorophylls and photosynthetic 14CO2 fixation rates are adversely affected due to sodium chloride salinity. Plants grown in the presence of NaCl show increase in C4 acid percentage with increase in labelling of organic acids in light. Labelling of amino acids (particularly alanine) and sugars (sucrose) is affected by NaCl. Enzyme studies reveal that PEP-carboxylase is stimulated at all concentrations of NaCl but higher concentrations affected the activity of RuBP-Carboxylase. (author)

  4. Purification, crystallization and preliminary crystallographic analysis of biotin protein ligase from Staphylococcus aureus

    International Nuclear Information System (INIS)

    The biotin protein ligase from S. aureus has been overexpressed in E. coli, purified, crystallized by the hanging-drop vapour-diffusion method and analysed using X-ray diffraction. Biotin protein ligase from Staphylococcus aureus catalyses the biotinylation of acetyl-CoA carboxylase and pyruvate carboxylase. Recombinant biotin protein ligase from S. aureus has been cloned, expressed and purified. Crystals were grown using the hanging-drop vapour-diffusion method using PEG 8000 as the precipitant at 295 K. X-ray diffraction data were collected to 2.3 Å resolution from crystals using synchrotron X-ray radiation at 100 K. The diffraction was consistent with the tetragonal space group P42212, with unit-cell parameters a = b = 93.665, c = 131.95

  5. AcEST: DK960177 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 9. 5' end sequence. DK960177 CL2Contig2 Show DK960177 Clone id TST39A01NGRL0006_L09 Library TST39 Length 739... Definition Adiantum capillus-veneris mRNA. clone: TST39A01NGRL0006_L09. 5' end sequence. Accession DK960177...tabase search programs, Nucleic Acids Res. 25:3389-3402. Query= DK960177|Adiantum capillus-veneris mRNA, clo...ylase small ch... 178 3e-44 sp|P16031|RBS_LARLA Ribulose bisphosphate carboxylase small chai... 177 4e-44 sp...|Q40004|RBS_HORVU Ribulose bisphosphate carboxylase small chai... 177 4e-44 sp|P1

  6. AcEST: BP915319 [AcEST

    Lifescience Database Archive (English)

    Full Text Available .. 33 1.1 sp|Q9KVT8|PURK_VIBCH Phosphoribosylaminoimidazole carboxylase AT... 32 1.4 sp|Q8UW76|TBX20_CHICK T...IPHPIQGSLPPYSRLGMPLTPSAIASSMQ 405 >sp|Q9KVT8|PURK_VIBCH Phosphoribosylaminoimidazole carboxylase ATPase subu...yrococcus ab... 30 7.1 sp|Q9HPP1|SUCC_HALSA Succinyl-CoA ligase [ADP-forming] subunit b... 30 7.1 sp|P19158|...o... 33 8.8 tr|A1ASJ2|A1ASJ2_PELPD Methyl-accepting chemotaxis sensory trans... 33 8.8 tr|Q08PW4|Q08PW4_STIAU Branched-chain ami...no acid aminotransferas... 33 8.8 tr|B2YIG2|B2YIG2_9BACT Cpn60 (Fragment) OS=uncultured

  7. Dicty_cDB: Contig-U16305-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 321 8e-86 ( Q19842 ) RecName: Full=Propionyl-CoA carboxylase alpha chain, mi... 321 8e-86 CP000613_395( CP000613 |pid...AK296771_1( AK296771 |pid:none) Homo sapiens cDNA FLJ59564 complet... 315 5e-84 ( P05165 ) RecName: Full=Propionyl-CoA carboxyla...:none) Mus musculus propionyl CoA-carboxy... 309 4e-82 AM270418_25( AM270418 |pid:none) ...-CoA carboxylase alpha chain, mi... 305 4e-81 A34337( A34337 ;A30871)propionyl-CoA carboxyla...:none) Rhodopseudomonas palustris BisB... 302 4e-80 M22631_1( M22631 |pid:none) Rat alpha-propionyl-CoA carboxyla

  8. AcEST: DK960529 [AcEST

    Lifescience Database Archive (English)

    Full Text Available |TOR1A_MACFA Torsin-1A OS=Macaca fascicularis GN=TOR1A ... 33 1.7 sp|P85111|RCA_VITSX Ribulose bisphosp...|A9PFQ2_POPTR Putative uncharacterized protein OS=Popul... 228 2e-58 tr|Q06B51|Q06B51_ACERU Chloroplast ribulose-1,5-bisphosp...I 649 +K+GI Sbjct: 180 AKMGI 184 >tr|Q06B50|Q06B50_ACERU Chloroplast ribulose-1,5-bisphosphate carboxylase/o...9 Definition Adiantum capillus-veneris mRNA. clone: TST39A01NGRL0007_K16. 5' end sequence. Accession DK960529 Tissue type pr...|Q7X999|RCA2_LARTR Ribulose bisphosphate carboxylase/oxygenase activase 2, chloroplastic OS=Larrea tri

  9. AcEST: DK944135 [AcEST

    Lifescience Database Archive (English)

    Full Text Available y10Aa OS=Baci... 32 1.7 sp|Q9BYV9|BACH2_HUMAN Transcription regulator protei...A8QIH7_MORAL Chloroplast ribulose-1,5-bisphosphate car... 271 2e-71 tr|A9NV87|A9NV87_PICSI Putative uncharacterized pr...e-53 tr|Q06B51|Q06B51_ACERU Chloroplast ribulose-1,5-bisphosphate car... 210 5e-53 tr|A9PG25|A9PG25_POPTR Putative uncharacteri...DDGSCLY 312 >tr|Q06B48|Q06B48_ACERU Chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase activase large protein is...|Q7X9A0|RCA1_LARTR Ribulose bisphosphate carboxylase/oxygenase activase 1, chloroplastic OS=Larrea triden

  10. AcEST: DK943967 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 2. Query= DK943967|Adiantum capillus-veneris mRNA, clone: YMU02A01NGRL0004_I17, 5' (504 letters) Database: uniprot_spr...3|Y833_METJA Uncharacterized protein MJ0833 OS=Methanoca... 33 0.75 sp|O74252|STE12_EMENI Transcription factor steA OS=Emeri...Q06B48|Q06B48_ACERU Chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase activase large protein isofo...oxygenase ... 43 9e-09 sp|P58555|RCA_ANASP Ribulose bisphosphate carboxylase/oxygenase ... 37 3e-06 sp|Q5824...|Q674R7|ATG9B_HUMAN Autophagy-related protein 9B OS=Homo sapie... 30 8.3 >sp|P10896|RCA_ARATH Ribulose bisphosp

  11. AcEST: DK949080 [AcEST

    Lifescience Database Archive (English)

    Full Text Available otein endopeptidase O... 32 2.8 sp|Q9BYV9|BACH2_HUMAN Transcription regulator protein BACH2 OS=H... 32 2.8 sp...-86 tr|Q06B49|Q06B49_ACERU Chloroplast ribulose-1,5-bisphosphate car... 317 4e-85 tr|A9PG25|A9PG25_POPTR Putative uncharacterized pr...Q06B50|Q06B50_ACERU Chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase activase large protein is...2 Definition Adiantum capillus-veneris mRNA. clone: TST38A01NGRL0005_A14. 5' end sequence. Accession DK949080 Tissue type pr...|Q7X999|RCA2_LARTR Ribulose bisphosphate carboxylase/oxygenase activase 2, chloroplastic OS=Larrea tri

  12. AcEST: DK947455 [AcEST

    Lifescience Database Archive (English)

    Full Text Available |Q9BYV9|BACH2_HUMAN Transcription regulator protein BACH2 OS=H... 32 2.3 sp|P15257|HNF1A_RAT Hepatocyte nu...e-64 tr|Q19RP2|Q19RP2_9MAGN Ribulose-1,5-bisphosphate carboxylase/oxy... 246 7e-64 tr|A9NV87|A9NV87_PICSI Putative uncharacteri...ery= DK947455|Adiantum capillus-veneris mRNA, clone: YMU02A01NGRL0015_P10, 5' (58...|Q7X9A0|RCA1_LARTR Ribulose bisphosphate carboxylase/oxygenase activase 1, chloroplastic OS=Larrea tri...AST: a new generation of protein database search programs, Nucleic Acids Res. 25:3389-3402. Query= DK947455|Adiantum capillus-veneris

  13. Light-stimulated transcription of genes for two chloroplast polypeptides in isolated pea leaf nuclei

    OpenAIRE

    Gallagher, Thomas F; Ellis, R. John

    1982-01-01

    Nuclei isolated from both light-grown and dark-grown leaves of Pisum sativum by Percoll density gradient centrifugation incorporate labelled UTP into RNA when supplemented with the other three nucleoside triphosphates. The RNA is heterodisperse, with transcripts up to at least 25S in size. Among these transcripts are sequences hybridizing to cloned DNA probes for wheat rRNA and two abundant chloroplast polypeptides of Pisum, viz. the small subunit of ribulose bisphosphate carboxylase and a po...

  14. Propionic acidemia: clinical course and outcome in 55 pediatric and adolescent patients

    OpenAIRE

    Grünert Sarah C; Müllerleile Stephanie; De Silva Linda; Barth Michael; Walter Melanie; Walter Kerstin; Meissner Thomas; Lindner Martin; Ensenauer Regina; Santer René; Bodamer Olaf A; Baumgartner Matthias R; Brunner-Krainz Michaela; Karall Daniela; Haase Claudia

    2013-01-01

    Abstract Background Propionic acidemia is an inherited disorder caused by deficiency of propionyl-CoA carboxylase. Although it is one of the most frequent organic acidurias, information on the outcome of affected individuals is still limited. Study design/methods Clinical and outcome data of 55 patients with propionic acidemia from 16 European metabolic centers were evaluated retrospectively. 35 patients were diagnosed by selective metabolic screening while 20 patients were identified by newb...

  15. Mechanism of Inhibition of Aliphatic Epoxide Carboxylation by the Coenzyme M Analog 2-Bromoethanesulfonate*

    OpenAIRE

    Boyd, Jeffrey M.; Clark, Daniel D.; Kofoed, Melissa A.; Ensign, Scott A.

    2010-01-01

    The bacterial metabolism of epoxypropane formed from propylene oxidation uses the atypical cofactor coenzyme M (CoM, 2-mercaptoethanesulfonate) as the nucleophile for epoxide ring opening and as a carrier of intermediates that undergo dehydrogenation, reductive cleavage, and carboxylation to form acetoacetate in a three-step metabolic pathway. 2-Ketopropyl-CoM carboxylase/oxidoreductase (2-KPCC), the terminal enzyme of this pathway, is the only known member of the disulfide oxidoreductase fam...

  16. Role of the photosystem II-associated CAH3 in the oxygen evolving machinery in Chlamydomonas reinhardtii

    OpenAIRE

    Rende, Umut

    2012-01-01

    One of the most abundant proteins on the Earth is ribulose-1,5-biphosphate carboxylase/oxygenase (RUBISCO). RUBISCO is a CO2 fixing enzyme in oxygenic photosynthetic organisms that it has low affinity for CO2. When CO2 is the limiting factor in the environment, RUBISCO works inefficiently due to its oxygenase activity. Some higher plants and aquatic photosynthetic organisms, such as the green alga Chlamydomonas reinhardtii; therefore, evolved Carbon Concentrating Mechanisms to acquire and to ...

  17. Regulation of carbon dioxide fixation in facultatively autotrophic bacteria. A phisiological and genetical study.

    OpenAIRE

    Meijer, Wilhelmus Gerhardus

    1990-01-01

    Autotrophic bactcria are capable of CO2 fixation via the Calvin cycle, emplofng energy derived from the oxidation of anorganic substrates (e.g. Hz), simple organic substrates (one-carbon compounds, e.g. methanol, formate), or from light. Ribulose-1,5-bisphospbate carboxylase/oxygenase (RuBisC/O), pbosphoribulokinase (PRK) and fructosebisphosphatase (FBPase) are the unique enzymes of this autotrophic pathway (Chapter 1). ... Zie: Summary

  18. Photosynthetic 14CO2 fixation in the leaves of rice and some other species

    International Nuclear Information System (INIS)

    The activity of CO2-fixing enzymes and the initial products of photosynthetic 14CO2 fixation in two rice varieties, the one japonica and the other indica, were examined, comparing with those in several C3 and C4 crop species. Corn and barnyard grass as C4 plants and barley and wheat as C3 plants were used as comparison materials. The plants were cultured at 25 deg. C in daytime and 20 deg. C in night under natural light in a phytotron. After about a month from sowing, the fully expanded leaf blades were subjected to the experiments. The fresh leaf blades of one gram were homogenized in 5 ml of 50 mM Tris-H2SO4 buffer (pH 7.7) containing 4 mM EDTA, 10 mM dithiothreitol and 50 mg of polyamide powder. After filtration, the supernatant was used as the crude enzyme extract for assaying the activity of RuDP carboxylase and PEP carboxylase. The experiments revealed that (1) in C3 plants, the RuDP carboxylase activity was higher, and the PEP carboxylase activity was lower than those in C4 plants; (2) the initial products of photosynthetic 14CO2 fixation in the japonica rice variety were mainly PGA and other sugar phosphates as in barley, whereas in corn, they were malic and aspartic acids; (3) the 14C incorporation into glycine and serine was high in the japonica rice and barley, whereas low in corn. From these results, rice could be regarded as C3 plant. (Iwakiri, K.)

  19. Fatty acid biosynthesis VII. Substrate control of chain-length of products synthesised by rat liver fatty acid synthetase

    DEFF Research Database (Denmark)

    Hansen, Heinz Johs. Max; Carey, E.M.; Dils, R.

    1970-01-01

    - 1. Gas-liquid and paper chromatography have been used to determine the chain-lengths of fatty acids synthesised by purified rat liver fatty acid synthetase from [1-14C]acetyl-CoA, [1,3-14C2]malonyl-CoA and from [1-14C]acetyl-CoA plus partially purified rat liver acetyl-CoA carboxylase. - 2. A...

  20. Targeting of proteins to the thylakoid lumen by the bipartite transit peptide of the 33 kd oxygen-evolving protein.

    OpenAIRE

    Ko, K.; Cashmore, A. R.

    1989-01-01

    Various chimeric precursors and deletions of the 33 kd oxygen-evolving protein (OEE1) were constructed to study the mechanism by which chloroplast proteins are imported and targeted to the thylakoid lumen. The native OEE1 precursor was imported into isolated chloroplasts, processed and localized in the thylakoid lumen. Replacement of the OEE1 transit peptide with the transit peptide of the small subunit of ribulose-1,5-bisphosphate carboxylase, a stromal protein, resulted in redirection of ma...

  1. Cytonuclear Evolution of Rubisco in Four Allopolyploid Lineages

    OpenAIRE

    Gong, Lei; Olson, Mischa; Wendel, Jonathan F.

    2014-01-01

    Allopolyploidization in plants entails the merger of two divergent nuclear genomes, typically with only one set (usually maternal) of parental plastidial and mitochondrial genomes and with an altered cytonuclear stoichiometry. Thus, we might expect cytonuclear coevolution to be an important dimension of allopolyploid evolution. Here, we investigate cytonuclear coordination for the key chloroplast protein rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase), which is composed of nuclear-e...

  2. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    OpenAIRE

    Jun-Fei Gu; Ming Qiu; Jian-Chang Yang

    2013-01-01

    Maize-specific pyruvate orthophosphate dikinase (PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase (PCK). The wild-type (WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments, well-watered (WW), moderate drought (MD) and severe drought (SD), were imposed from 9 d post-anthesis till maturity. Leaf physiological and biochemical traits, root activ...

  3. SoyProLow: A protein database enriched in low abundant soybean proteins

    OpenAIRE

    Tavakolan, Mona; Alkharouf, Nadim W; Matthews, Benjamin F.; Natarajan, Savithiry S.

    2014-01-01

    Soybeans are an important legume crop that contain 2 major storage proteins, β-conglycinin and glycinin, which account about 70- 80% of total seed proteins. These abundant proteins hinder the isolation and characterization of several low abundant proteins in soybean seeds. Several protein extraction methodologies were developed in our laboratory to decrease these abundant storage proteins in seed extracts and to also decrease the amount of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuB...

  4. Contrasting Diversity and Host Association of Ectomycorrhizal Basidiomycetes versus Root-Associated Ascomycetes in a Dipterocarp Rainforest

    OpenAIRE

    Sato, Hirotoshi; Tanabe, Akifumi S; Toju, Hirokazu

    2015-01-01

    Root-associated fungi, including ectomycorrhizal and root-endophytic fungi, are among the most diverse and important belowground plant symbionts in dipterocarp rainforests. Our study aimed to reveal the biodiversity, host association, and community structure of ectomycorrhizal Basidiomycota and root-associated Ascomycota (including root-endophytic Ascomycota) in a lowland dipterocarp rainforest in Southeast Asia. The host plant chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase large...

  5. The oxygen and carbon dioxide compensation points of C3 plants: possible role in regulating atmospheric oxygen.

    Science.gov (United States)

    Tolbert, N E; Benker, C; Beck, E

    1995-11-21

    The O2 and CO2 compensation points (O2 and CO2) of plants in a closed system depend on the ratio of CO2 and O2 concentrations in air and in the chloroplast and the specificities of ribulose bisphosphate carboxylase/oxygenase (Rubisco). The photosynthetic O2 is defined as the atmospheric O2 level, with a given CO2 level and temperature, at which net O2 exchange is zero. In experiments with C3 plants, the O2 with 220 ppm CO2 is 23% O2; O2 increases to 27% with 350 ppm CO2 and to 35% O2 with 700 ppm CO2. At O2 levels below the O2, CO2 uptake and reduction are accompanied by net O2 evolution. At O2 levels above the O2, net O2 uptake occurs with a reduced rate of CO2 fixation, more carbohydrates are oxidized by photorespiration to products of the C2 oxidative photosynthetic carbon cycle, and plants senesce prematurely. The CO2 increases from 50 ppm CO2 with 21% O2 to 220 ppm with 100% O2. At a low CO2/high O2 ratio that inhibits the carboxylase activity of Rubisco, much malate accumulates, which suggests that the oxygen-insensitive phosphoenolpyruvate carboxylase becomes a significant component of the lower CO2 fixation rate. Because of low global levels of CO2 and a Rubisco specificity that favors the carboxylase activity, relatively rapid changes in the atmospheric CO2 level should control the permissive O2 that could lead to slow changes in the immense O2 pool. PMID:11607591

  6. Influence of temperature on measurements of the CO2 compensation point: differences between the Laisk and O2-exchange methods

    OpenAIRE

    Walker, Berkley J.; Cousins, Asaph B.

    2013-01-01

    The CO2 compensation point in the absence of day respiration (Γ*) is a key parameter for modelling leaf CO2 exchange. Γ* links the kinetics of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) with the stoichiometry of CO2 released per Rubisco oxygenation from photorespiration (α), two essential components of biochemical models of photosynthesis. There are two main gas-exchange methods for measuring Γ*: (i) the Laisk method, which requires estimates of mesophyll conductance to CO2 (g ...

  7. Glucconeogenesis in Dairy Cows: The Secret of Making Sweet Milk from Sour Dough

    DEFF Research Database (Denmark)

    Aschenbach, Jörg R; Kristensen, Niels Bastian; Donkin, Shawn S;

    2010-01-01

    regulation is relevant for regulating precursor entry into gluconeogenesis (propionate, alanine and other amino acids, lactate, and glycerol). Promoters of the bovine pyruvate carboxylase (PC) and PEPCK genes are directly controlled by metabolic products. The final steps decisive for glucose release...... leading to fatty liver and ketosis. Increasing feed intake and provision of glucogenic precursors from the diet are important to ameliorate these disturbances. An improved understanding of the complex mechanisms underlying gluconeogenesis may further improve our options to enhance the postpartum health...

  8. A Rubisco mutant that confers growth under a normally “inhibitory” oxygen concentration†

    OpenAIRE

    Satagopan, Sriram; Scott, Stephanie S.; Smith, Todd G.; Tabita, F. Robert

    2009-01-01

    Ribulose 1, 5-bisphosphate (RuBP) carboxylase/oxygenase (Rubisco) is a globally significant biocatalyst that facilitates the removal and sequestration of CO2 from the biosphere. Rubisco-catalyzed CO2 reduction thus provides virtually all the organic carbon utilized by living organisms. Despite catalyzing the rate-limiting step of photosynthetic and chemoautotrophic CO2 assimilation, Rubisco is markedly inefficient as the competition between O2 and CO2 for the same substrate limits the ability...

  9. Wild Manihot Species Do Not Possess C4 Photosynthesis

    OpenAIRE

    CALATAYUD, P.‐A.; BARÓN, C. H.; VELÁSQUEZ, H.; ARROYAVE, J. A.; LAMAZE, T.

    2002-01-01

    Cultivated cassava (Manihot esculenta) has a higher rate of photosynthesis than is usual for C3 plants and photosynthesis is not light saturated. For these reasons it has been suggested that cultivated cassava could be derived from wild species possessing C4 photosynthesis. The natural abundance of 13C and activities of phosphoenolpyruvate carboxylase and phosphoglycolate phosphatase were measured in leaves of 20 wild cassava species to test this hypothesis. All the species studied, including...

  10. PHYLOGENETIC ANALYSIS AMONG FOUR SECTIONS OF GENUS DENDROBIUM SW. (ORCHIDACEAE) IN PENINSULAR MALAYSIA USING RBCL SEQUENCE DATA

    OpenAIRE

    2013-01-01

    Phylogenetic analysis using chloroplast DNA, the ribulose-bisphosphate carboxylase gene (rbcL), was conducted to examine relationship among four sections of the genus Dendrobium (Orchidaceae): Aporum, Crumenata, Strongyle, and Bolbidium in Peninsular Malaysia. Classifications based on morphological characters have not been able to clearly divide these four sections, therefore deeper and detailed analyses are required to ascertain their status. In this study, the phylogenetic relationships amo...

  11. Obesity-Related Chronic Kidney Disease—The Role of Lipid Metabolism

    OpenAIRE

    Peter Mount; Matthew Davies; Suet-Wan Choy; Natasha Cook; David Power

    2015-01-01

    Obesity is an independent risk factor for chronic kidney disease (CKD). The mechanisms linking obesity and CKD include systemic changes such as high blood pressure and hyperglycemia, and intrarenal effects relating to lipid accumulation. Normal lipid metabolism is integral to renal physiology and disturbances of renal lipid and energy metabolism are increasingly being linked with kidney disease. AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) are important regulators of f...

  12. Quantitative Measurement of Urinary Excretion of 3-Hydroxyisovaleryl Carnitine by LC–MS/MS as an Indicator of Biotin Status in Humans

    OpenAIRE

    Horvath, Thomas D.; Stratton, Shawna L; Bogusiewicz, Anna; Owen, Suzanne N.; Mock, Donald M; Moran, Jeffery H.

    2010-01-01

    Abnormally increased urinary excretion of 3-hydroxyisovaleryl carnitine (3HIA-carnitine) results from impairment in leucine catabolism caused by reduced activity of the biotin-dependent enzyme 3-methylcrotonyl-CoA carboxylase. Accordingly, urinary 3HIA-carnitine might reflect biotin status. Here, we describe an LC–MS/MS method for accurately quantitating the urinary concentration of 3HIA-carnitine at concentrations that are typical for excretion rates that are normal or only modestly increase...

  13. Precursors of novel Gla-containing conotoxins contain a carboxy-terminal recognition site that directs gamma-carboxylation

    DEFF Research Database (Denmark)

    Brown, Mark A; Begley, Gail S; Czerwiec, Eva;

    2005-01-01

    Vitamin K-dependent gamma-glutamyl carboxylase catalyzes the conversion of glutamyl residues to gamma-carboxyglutamate. Its substrates include vertebrate proteins involved in blood coagulation, bone mineralization, and signal transduction and invertebrate ion channel blockers known as conotoxins....... novel precursor structure for vitamin K-dependent polypeptides. It also provides the first formal evidence to prove that gamma-carboxylation occurs as a post-translational rather than a cotranslational process....

  14. C-4 plants use fluctuating light less efficiently than do C-3 plants: a study of growth, photosynthesis and carbon isotope discrimination

    Czech Academy of Sciences Publication Activity Database

    Kubásek, Jiří; Urban, Otmar; Šantrůček, Jiří

    2013-01-01

    Roč. 149, č. 4 (2013), s. 528-539. ISSN 0031-9317 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA ČR(CZ) GAP501/12/1261 Institutional support: RVO:67179843 ; RVO:60077344 Keywords : bundel-sheath leakiness * agrass genus muhlebergia * phosphenolpyruvate carboxylase * CO2 uptake * leaves * induction * sunflecks * responses * leaf Subject RIV: EH - Ecology, Behaviour; BO - Biophysics (BC-A) Impact factor: 3.262, year: 2013

  15. Chloroplast gene sequences and the study of plant evolution.

    OpenAIRE

    Clegg, M T

    1993-01-01

    A large body of sequence data has accumulated for the chloroplast-encoded gene ribulose-1,5-biphosphate carboxylase/oxygenase (rbcL) as the result of a cooperative effort involving many laboratories. The data span all seed plants, including most major lineages from the angiosperms, and as such they provide an unprecedented opportunity to study plant evolutionary history. The full analysis of this large data set poses many problems and opportunities for plant evolutionary biologists and for bi...

  16. Ligand Specificity of Group I Biotin Protein Ligase of Mycobacterium tuberculosis

    OpenAIRE

    Purushothaman, Sudha; Gupta, Garima; Srivastava, Richa; Ramu, Vasanthakumar Ganga; Surolia, Avadhesha

    2008-01-01

    Background: Fatty acids are indispensable constituents of mycolic acids that impart toughness & permeability barrier to the cell envelope of M. tuberculosis. Biotin is an essential co-factor for acetyl-CoA carboxylase (ACC) the enzyme involved in the synthesis of malonyl-CoA, a committed precursor, needed for fatty acid synthesis. Biotin carboxyl carrier protein (BCCP) provides the co-factor for catalytic activity of ACC. Methodology/Principal Findings: BPL/BirA (Biotin Protein L...

  17. Biotin

    OpenAIRE

    Zempleni, Janos; Wijeratne, Subhashinee S.K.; Hassan, Yousef I.

    2009-01-01

    Biotin is a water-soluble vitamin and serves as a coenzyme for five carboxylases in humans. Biotin is also covalently attached to distinct lysine residues in histones, affecting chromatin structure and mediating gene regulation. This review describes mammalian biotin metabolism, biotin analysis, markers of biotin status, and biological functions of biotin. Proteins such as holocarboxylase synthetase, biotinidase, and the biotin transporters SMVT and MCT1 play crucial roles in biotin homeostas...

  18. Plasma concentration of 3-hydroxyisovaleryl carnitine is an early and sensitive indicator of marginal biotin deficiency in humans1234

    OpenAIRE

    Stratton, Shawna L.; Horvath, Thomas D.; Bogusiewicz, Anna; Matthews, Nell I.; Henrich, Cindy L; Spencer, Horace J.; Moran, Jeffery H.; Mock, Donald M.

    2010-01-01

    Background: Blood-based indicators of biotin status in humans were shown to be useful tools in several clinical situations, including pregnancy. We previously validated the activity of the biotin-dependent enzyme propionyl-coenzyme A carboxylase (PCC) in lymphocytes as a sensitive and specific blood-based indicator of marginal degrees of biotin deficiency. However, the measurement of PCC activity in population studies presents substantial analytic challenges. 3-Hydroxyisovaleryl carnitine (3H...

  19. Biotin dependency due to a defect in biotin transport

    OpenAIRE

    Mardach, Rebecca; Zempleni, Janos; Wolf, Barry; Martin J. Cannon; Jennings, Michael L.; Cress, Sally; Boylan, Jane; Roth, Susan; Cederbaum, Stephen; Mock, Donald M.

    2002-01-01

    We describe a 3-year-old boy with biotin dependency not caused by biotinidase, holocarboxylase synthetase, or nutritional biotin deficiency. We sought to define the mechanism of his biotin dependency. The child became acutely encephalopathic at age 18 months. Urinary organic acids indicated deficiency of several biotin-dependent carboxylases. Symptoms improved rapidly following biotin supplementation. Serum biotinidase activity and Biotinidase gene sequence were normal. Activities of biotin-d...

  20. Distinct Amino Termini of Two Human HCS Isoforms Influence Biotin Acceptor Substrate Recognition*

    OpenAIRE

    Ingaramo, Maria; Beckett, Dorothy

    2009-01-01

    The human holocarboxylase synthetase (HCS) catalyzes transfer of biotin to biotin-dependent carboxylases, and the enzyme is therefore of fundamental importance for many physiological processes, including fatty acid synthesis, gluconeogenesis, and amino acid catabolism. In addition, the enzyme functions in regulating transcription initiation at several genes that code for proteins involved in biotin metabolism. Two major forms of HCS exist in humans, which differ at the amino terminus by 57 am...

  1. Biochemical Properties and Biological Function of a Monofunctional Microbial Biotin Protein Ligase

    OpenAIRE

    Daniels, Kyle G.; Beckett, Dorothy

    2010-01-01

    Biotin protein ligases constitute a family of enzymes that catalyze biotin linkage to biotin-dependent carboxylases. In bacteria these enzymes are functionally divided into two classes; the monofunctional enzymes that only catalyze biotin addition and the bifunctional enzymes that also bind to DNA to regulate transcription initiation. Biochemical and biophysical studies of the bifunctional Escherichia coli ligase suggest that several properties of the enzyme have evolved to support its additi...

  2. AcEST: BP913171 [AcEST

    Lifescience Database Archive (English)

    Full Text Available YMU001_000027_C08 408 Adiantum capillus-veneris mRNA. clone: YMU001_000027_C08. BP913171 CL860Co ... t sp_hit_id Q06881 Definition sp|Q06881|BCCP_ANASP Biotin ... carboxyl carrier protein of acetyl-CoA carboxylase ... cant alignments: (bits) Value sp|Q06881|BCCP_ANASP Biotin ... carboxyl carrier protein of acetyl-C... 37 0.030 s ...

  3. A versatile Escherichia coli strain for identification of biotin transporters and for biotin quantification

    OpenAIRE

    Finkenwirth, Friedrich; Kirsch, Franziska; Eitinger, Thomas

    2013-01-01

    Biotin is an essential cofactor of carboxylase enzymes in all kingdoms of life. The vitamin is produced by many prokaryotes, certain fungi, and plants. Animals depend on biotin uptake from their diet and in humans lack of the vitamin is associated with serious disorders. Many aspects of biotin metabolism, uptake, and intracellular transport remain to be elucidated. In order to characterize the activity of novel biotin transporters by a sensitive assay, an Escherichia coli strain lacking both ...

  4. Conservation of the Biotin Regulon and the BirA Regulatory Signal in Eubacteria and Archaea

    OpenAIRE

    Rodionov, Dmitry A.; Mironov, Andrei A.; Gelfand, Mikhail S.

    2002-01-01

    Biotin is a necessary cofactor of numerous biotin-dependent carboxylases in a variety of microorganisms. The strict control of biotin biosynthesis in Escherichia coli is mediated by the bifunctional BirA protein, which acts both as a biotin–protein ligase and as a transcriptional repressor of the biotin operon. Little is known about regulation of biotin biosynthesis in other bacteria. Using comparative genomics and phylogenetic analysis, we describe the biotin biosynthetic pathway and the Bir...

  5. AcEST: BP912679 [AcEST

    Lifescience Database Archive (English)

    Full Text Available YMU001_000021_F06 573 Adiantum capillus-veneris mRNA. clone: YMU001_000021_F06. BP912679 CL860Co ... t sp_hit_id P49786 Definition sp|P49786|BCCP_BACSU Biotin ... carboxyl carrier protein of acetyl-CoA carboxylase ... cant alignments: (bits) Value sp|P49786|BCCP_BACSU Biotin ... carboxyl carrier protein of acetyl-C... 35 2e-04 s ...

  6. Biotin Sensing at the Molecular Level1–3

    OpenAIRE

    Beckett, Dorothy

    2009-01-01

    Biotin influences transcription in organisms from bacteria to humans. The enzyme, biotin protein ligase, which catalyzes post-transcriptional biotin addition to biotin-dependent carboxylases, plays a central roll in transmitting the demand for biotin to gene expression. The molecular mechanism of this communication in bacteria is well understood and involves competing protein:protein interactions. Biochemical measurements indicate that this competition is kinetically controlled. In humans, th...

  7. Identification and assessment of markers of biotin status in healthy adults

    OpenAIRE

    Eng, Wei Kay; Giraud, David; Schlegel, Vicki L.; Wang, Dong; Lee, Bo Hyun; Zempleni, Janos

    2013-01-01

    Human biotin requirements are unknown and the identification of reliable markers of biotin status is necessary to fill this knowledge gap. Here, we used an outpatient feeding protocol to create states of biotin deficiency, sufficiency and supplementation in sixteen healthy men and women. A total of twenty possible markers of biotin status were assessed, including the abundance of biotinylated carboxylases in lymphocytes, the expression of genes from biotin metabolism and the urinary excretion...

  8. AcEST: BP915012 [AcEST

    Lifescience Database Archive (English)

    Full Text Available YMU001_000065_E02 510 Adiantum capillus-veneris mRNA. clone: YMU001_000065_E02. BP915012 CL860Co ... t sp_hit_id Q06881 Definition sp|Q06881|BCCP_ANASP Biotin ... carboxyl carrier protein of acetyl-CoA carboxylase ... cant alignments: (bits) Value sp|Q06881|BCCP_ANASP Biotin ... carboxyl carrier protein of acetyl-C... 37 6e-05 s ...

  9. Scientific Opinion on Dietary Reference Values for biotin

    OpenAIRE

    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA)

    2014-01-01

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for biotin. Biotin is a water-soluble vitamin which serves as a co-factor for several carboxylases that play critical roles in the synthesis of fatty acids, the catabolism of branched-chain amino acids and gluconeogenesis. Dietary biotin deficiency is rare. Data on biomarkers of biotin intake or status are insufficient to be used in determinin...

  10. AcEST: BP915507 [AcEST

    Lifescience Database Archive (English)

    Full Text Available YMU001_000072_D11 512 Adiantum capillus-veneris mRNA. clone: YMU001_000072_D11. BP915507 CL860Co ... t sp_hit_id Q06881 Definition sp|Q06881|BCCP_ANASP Biotin ... carboxyl carrier protein of acetyl-CoA carboxylase ... cant alignments: (bits) Value sp|Q06881|BCCP_ANASP Biotin ... carboxyl carrier protein of acetyl-C... 37 6e-05 s ...

  11. Dicty_cDB: SHC207 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available m adolescentis ATC... 164 2e-39 ( P12045 ) RecName: Full=Phosphoribosylaminoimidazole carboxylase ... 164 2e...HWTIEGCVTSQFEQLIRCV CGLPLGSVDFTKSXXSV Translated Amino Acid sequence (All Frames) Fram...yvkplhqlncqnifinkpmklv* rllvpmvwlvllpsnyl**ktmkqvntl*w*mnwhqdhtivvigpskvv*plnlnn*fvv fvvclwvqsislkvsxqw Fram...nce update 2002. 9.10 Translated Amino Acid sequence ---SFNDLKSAIEKIGYPAILKSNTMGYDGKGQVKLTDQVDLEQAWKKVTSETCA...c survey sequence. 44 3.3 1 CW222532 |CW222532.1 104_658_11202424_148_37183_064 Sorghum methylati

  12. Biotin protein ligase from Corynebacterium glutamicum: role for growth and L: -lysine production.

    Science.gov (United States)

    Peters-Wendisch, P; Stansen, K C; Götker, S; Wendisch, V F

    2012-03-01

    Corynebacterium glutamicum is a biotin auxotrophic Gram-positive bacterium that is used for large-scale production of amino acids, especially of L-glutamate and L-lysine. It is known that biotin limitation triggers L-glutamate production and that L-lysine production can be increased by enhancing the activity of pyruvate carboxylase, one of two biotin-dependent proteins of C. glutamicum. The gene cg0814 (accession number YP_225000) has been annotated to code for putative biotin protein ligase BirA, but the protein has not yet been characterized. A discontinuous enzyme assay of biotin protein ligase activity was established using a 105aa peptide corresponding to the carboxyterminus of the biotin carboxylase/biotin carboxyl carrier protein subunit AccBC of the acetyl CoA carboxylase from C. glutamicum as acceptor substrate. Biotinylation of this biotin acceptor peptide was revealed with crude extracts of a strain overexpressing the birA gene and was shown to be ATP dependent. Thus, birA from C. glutamicum codes for a functional biotin protein ligase (EC 6.3.4.15). The gene birA from C. glutamicum was overexpressed and the transcriptome was compared with the control strain revealing no significant gene expression changes of the bio-genes. However, biotin protein ligase overproduction increased the level of the biotin-containing protein pyruvate carboxylase and entailed a significant growth advantage in glucose minimal medium. Moreover, birA overexpression resulted in a twofold higher L-lysine yield on glucose as compared with the control strain. PMID:22159614

  13. Anticoagulant Rodenticide Intoxication in Animals – A Review

    OpenAIRE

    VALCHEV, Ivan; Binev, Rumen; YORDANOVA, Veska; Nikolov, Yordan

    2008-01-01

    The newest measures for the control of harmful rodent populations are from the anticoagulant rodenticide group, which are divided into 2 subgroups: first and second generations, and indandione derivatives. Non-target organisms are potentially at risk of direct consumption of baits (primary hazard) and of eating poisoned rodents (secondary hazard). Anticoagulant rodenticides inhibit the enzyme vitamin K-dependent carboxylase and thus impair the reactivation of vitamin K1, indirectly affecting ...

  14. Inhibitors of Fatty Acid Synthesis Induce PPAR α -Regulated Fatty Acid β -Oxidative Genes: Synergistic Roles of L-FABP and Glucose

    OpenAIRE

    Huan Huang; McIntosh, Avery L.; Martin, Gregory G.; Petrescu, Anca D.; Landrock, Kerstin K.; Danilo Landrock; Kier, Ann B.; Friedhelm Schroeder

    2013-01-01

    While TOFA (acetyl CoA carboxylase inhibitor) and C75 (fatty acid synthase inhibitor) prevent lipid accumulation by inhibiting fatty acid synthesis, the mechanism of action is not simply accounted for by inhibition of the enzymes alone. Liver fatty acid binding protein (L-FABP), a mediator of long chain fatty acid signaling to peroxisome proliferator-activated receptor-α (PPARα) in the nucleus, was found to bind TOFA and its activated CoA th...

  15. Skeletal muscle ACC2 S212 phosphorylation is not required for the control of fatty acid oxidation during exercise

    OpenAIRE

    O’Neill, Hayley M.; Lally, James S.; Galic, Sandra; Pulinilkunnil, Thomas; Ford, Rebecca J; Dyck, Jason R.B.; van Denderen, Bryce J.; Kemp, Bruce E.; Steinberg, Gregory R

    2015-01-01

    During submaximal exercise fatty acids are a predominant energy source for muscle contractions. An important regulator of fatty acid oxidation is acetyl-CoA carboxylase (ACC), which exists as two isoforms (ACC1 and ACC2) with ACC2 predominating in skeletal muscle. Both ACC isoforms regulate malonyl-CoA production, an allosteric inhibitor of carnitine palmitoyltransferase 1 (CPT-1); the primary enzyme controlling fatty acyl-CoA flux into mitochondria for oxidation. AMP-activated protein kinase...

  16. Isolation and kinetic characterisation of hydrophobically distinct populations of form I Rubisco

    OpenAIRE

    O’Donnelly, Kerry; Zhao, Guangyuan; Patel, Priya; Butt, M Salman; Mak, Lok Hang; Kretschmer, Simon; Woscholski, Rudiger; Barter, Laura M. C.

    2014-01-01

    Background Rubisco (Ribulose-1,5-bisphosphate carboxylase/oxygenase) is a Calvin Cycle enzyme involved in CO2 assimilation. It is thought to be a major cause of photosynthetic inefficiency, suffering from both a slow catalytic rate and lack of specificity due to a competing reaction with oxygen. Revealing and understanding the engineering rules that dictate Rubisco’s activity could have a significant impact on photosynthetic efficiency and crop yield. Results This paper describes the purifica...

  17. Isolation and Characterization of the Prochlorococcus Carboxysome Reveal the Presence of the Novel Shell Protein CsoS1D

    OpenAIRE

    Roberts, Evan W.; Cai, Fei; Cheryl A Kerfeld; Cannon, Gordon C.; Heinhorst, Sabine

    2012-01-01

    Cyanobacteria, including members of the genus Prochlorococcus, contain icosahedral protein microcompartments known as carboxysomes that encapsulate multiple copies of the CO2-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) in a thin protein shell that enhances the catalytic performance of the enzyme in part through the action of a shell-associated carbonic anhydrase. However, the exact mechanism by which compartmentation provides a catalytic advantage to the enzyme is ...

  18. Rubisco : easy purification and immunochemical determination

    OpenAIRE

    Groß, Ulrich

    2001-01-01

    Rubisco (Ribulose-1.5-bisphosphate carboxylase/oxygenase) from spinach was purified to homogeneity in one step by gel filtration. This enzyme is suitable for the generation of a specific antibody in rabbits. The enzyme concentration in spinach leaves amounted to 40 % of the total soluble protein. The specific antibody shows cross reaction with crude extracts from leaves of other higher plants. The enzymes subunits could be separated by denaturing preparative SDS gel electrophoresis.

  19. Carbon dioxide metabolism by Actinomyces viscosus: pathways for succinate and aspartate production.

    OpenAIRE

    Brown, A T; Breeding, L C

    1980-01-01

    14C-labeled bicarbonate was incorporated into trichloroacetic acid-insoluble material by cell suspensions of A. viscosus strain M100 and also into the four-carbon fermentation product, succinate, but not into the three-carbon fermentation product, lactate. The initial step in the conversion of 14C-labeled bicarbonate into both trichloroacetic acid-insoluble material and succinate was catalyzed by the enzyme phosphoenolypyruvate carboxylase, which served to convert the glycolytic intermediate,...

  20. Photorespiration

    OpenAIRE

    Peterhansel, Christoph; Horst, Ina; Niessen, Markus; Blume, Christian; Kebeish, Rashad; Kürkcüoglu, Sophia; Kreuzaler, Fritz

    2010-01-01

    Photorespiration is initiated by the oxygenase activity of ribulose-1,5-bisphosphate-carboxylase/oxygenase (RUBISCO), the same enzyme that is also responsible for CO2 fixation in almost all photosynthetic organisms. Phosphoglycolate formed by oxygen fixation is recycled to the Calvin cycle intermediate phosphoglycerate in the photorespiratory pathway. This reaction cascade consumes energy and reducing equivalents and part of the afore fixed carbon is again released as CO2. Because of this, ph...

  1. The role of phosphoenolpyruvate carboxykinase in a marine macroalga with C4-like photosynthetic characteristics.

    OpenAIRE

    Reiskind, J B; Bowes, G.

    1991-01-01

    Udotea flabellum is a marine, macroscopic green alga with C4-like photosynthetic characteristics, including little O2 inhibition of photosynthesis, a low CO2 compensation point, and minimal photorespiration; but it lacks anatomical features analogous to the Kranz compartmentation of C4 plants, and phosphoenolpyruvate carboxylase [PEPC; orthophosphate:oxaloacetate carboxy-lyase (phosphorylating), EC 4.1.1.31] activity is negligible. Phosphoenolpyruvate carboxykinase (PEPCK) activity (carboxyla...

  2. Photorespiration: metabolic pathways and their role in stress protection

    OpenAIRE

    Wingler, A; Lea, P J; Quick, W.P.; Leegood, R C

    2000-01-01

    Photorespiration results from the oxygenase reaction catalysed by ribulose-1,5-bisphosphate carboxylase/oxygenase. In this reaction glycollate-2-phosphate is produced and subsequently metabolized in the photorespiratory pathway to form the Calvin cycle intermediate glycerate-3-phosphate. During this metabolic process, CO2 and NH3 are produced and ATP and reducing equivalents are consumed, thus making photorespiration a wasteful process. However, precisely because of this inefficiency, photore...

  3. Infrageneric Phylogeny and Temporal Divergence of Sorghum (Andropogoneae, Poaceae) Based on Low-Copy Nuclear and Plastid Sequences

    OpenAIRE

    Qing Liu; Huan Liu; Jun Wen; Peterson, Paul M.

    2014-01-01

    The infrageneric phylogeny and temporal divergence of Sorghum were explored in the present study. Sequence data of two low-copy nuclear (LCN) genes, phosphoenolpyruvate carboxylase 4 (Pepc4) and granule-bound starch synthase I (GBSSI), from 79 accessions of Sorghum plus Cleistachne sorghoides together with those from outgroups were used for maximum likelihood (ML) and Bayesian inference (BI) analyses. Bayesian dating based on three plastid DNA markers (ndhA intron, rpl32-trnL, and rps16 intro...

  4. Effects of SO2 and sulfite on stromal metabolism

    International Nuclear Information System (INIS)

    SO2 appears to have multiple effects on chloroplast stromal metabolism. What is unique about metabolism in the chloroplast is reductive modulation of enzyme activity. The evidence summarized here implicates both the components of the modulation process and the light modulated enzymes and ribulosebisphosphate carboxylase in SO2-sensitivity. Interference with electron transport, acidification of the stroma, and depletion of phosphates will further complicate metabolism in the photosynthesizing chloroplast when sensitive plants are exposed to SO2. 35 refs., 6 figs

  5. Temperature-sensitive rubisco mutant of Chlamydomonas

    International Nuclear Information System (INIS)

    The Chlamydomonas reinhardtii mutant 68-4PP is a temperature-sensitive mutant that lacks photosynthetic ability at 350C, but is able to grow photosynthetically at 250C. Genetic analysis indicated that 68-4PP is a chloroplast mutant that is allelic with known Rubisco large-subunit structural-gene mutants, implying that 68-4PP also resulted from a mutation in the large-subunit gene. The 68-4PP mutant has about 35% of the wild-type level of Rubisco holoenzyme and carboxylase activity when grown at 250C, but it has less than 10% of normal holoenzyme and carboxylase activity when grown at 350C. However, [35S]-sulfate pulse labeling showed that Rubisco subunits were synthesized at normal rates at both temperatures. More significantly, the ratio of carboxylase activity in the absence and presence of oxygen at a limiting CO2 concentration (6.6 μM) was about 2.2 for the mutant enzyme, as compared to about 3.0 for the wild-type enzyme. The decreased ratio of the mutant enzyme is maternally inherited, indicating that this reduced oxygen sensitivity results from a mutation in chloroplast DNA. The authors have recently cloned the 68-4PP Rubisco large-subunit gene, and DNA sequencing is in progress

  6. Assessment of Photosynthesis Regulation in Mixotrophically Cultured Microalga Chlorella sorokiniana

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tingting; Kirchhoff, Helmut; Gargouri, Mahmoud; Feng, Jie; Cousins, Asaph B.; Pienkos, Philip T.; Gang, David R.; Chen, Shulin

    2016-11-01

    Mixotrophic growth of microalgae offers great potential as an efficient strategy for biofuel production. In this study, photosynthetic regulation of mixotrophically cultured Chlorella sorokiniana cells was systematically evaluated. Mixotrophic cells in the exponential growth phase showed the highest photosynthetic activity, where maximum photosynthetic O2 evolution was approximately 3- and 4-fold higher than cells in the same phase grown photoautotrophically in 1% CO2 (in air) and air, respectively. Additionally, characteristic chlorophyll fluorescence parameters demonstrated that no limitation in electron transport downstream of PSII was detected in mixotrophic cells. Up-regulation of photosynthetic activity was associated with high total ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylase activity and expression level of phosphoribulokinase (PRK). After 3 days, photosynthetic O2 evolution of mixotrophic cells that went to the stationary phase, was strongly reduced, with reduced photochemical efficiency and reorganization of the PSII complex. Simultaneously, enzymatic activity for Rubisco carboxylase and mRNA levels of Rubisco and PRK diminished. Importantly, there was almost no non-photochemical quenching for mixotrophic cells, whether grown in log or stationary phase. A decline in the quantum efficiency of PSII and an oxidized plastoquinone pool (PQ pool) was observed under N-depleted conditions during mixotrophic growth. These results demonstrate that photosynthesis is regulated differently in mixotrophically cultured C. sorokiniana cells than in cells grown under photoautotrophic conditions, with a particularly strong impact by nitrogen levels in the cells.

  7. Measurement of 2-carboxyarabinitol 1-phosphate in plant leaves by isotope dilution

    International Nuclear Information System (INIS)

    The level of 2-carboxyarabinitol 1-phosphate (CA1P) in leaves of 12 species was determined by an isotope dilution assay. 14C-labeled standard was synthesized from [2-14C]carboxyarabinitol 1,5-bisphosphate using acid phosphatase, and was added at the initial point of leaf extraction. Leaf CA1P was purified and its specific activity determined. CA1P was found in dark-treated leaves of all species examined, including spinach (Spinacea oleracea), wheat (Triticum aestivum), Arabidopsis thaliana, and maize (Zea mays). The highest amounts were found in bean (Phaseolus vulgaris) and petunia (Petunia hybrida), which had 1.5 to 1.8 moles CA1P per mole ribulose 1,5-bisphosphate carboxylase catalytic sites. Most species had intermediate amounts of CA1P (0.2 to 0.8 mole CA1P per mole catalytic sites). Such intermediate to high levels of CA1P support the hypothesis that CA1P functions in many species as a light-dependent regulator of ribulose 1,5-bisphosphate carboxylase activity and whole leaf photosynthetic CO2 assimilation. However, CA1P levels in spinach, wheat, and A. thaliana were particularly low (less than 0.09 mole CA1P per mole catalytic sites). In such species, CA1P does not likely have a significant role in regulating ribulose 1,5-bisphosphate carboxylase activity, but could have a different physiological role

  8. Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Mark Eiteman

    2007-07-31

    This report describes results toward developing a process to sequester CO{sub 2} centered on the enzymes PEP carboxylase and pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The study reports on strain development and process development. In the area of strain development, knockouts in genes which divert carbon from the enzymatic steps involved in CO{sub 2} consumption were completed, and were shown not to affect significantly the rate of CO{sub 2} sequestration and succinic acid generation. Furthermore, the pyc gene encoding for pyruvate carboxylase proved to be unstable when integrated onto the chromosome. In the area of process development, an optimal medium, pH and base counterion were obtained, leading to a sequestration rate as great as 800 mg/Lh. Detailed studies of gas phase composition demonstrated that CO{sub 2} composition has a significant affect on CO{sub 2} sequestration, while the presence of 'toxic' compounds in the gas, including NO{sub 2}, CO and SO{sub 2} did not have a detrimental effect on sequestration. Some results on prolonging the rate of sequestration indicate that enzyme activities decrease with time, suggesting methods to prolong enzyme activity may benefit the overall process.

  9. Impaired vitamin K recycling in uremia is rescued by vitamin K supplementation.

    Science.gov (United States)

    Kaesler, Nadine; Magdeleyns, Elke; Herfs, Marjolein; Schettgen, Thomas; Brandenburg, Vincent; Fliser, Danilo; Vermeer, Cees; Floege, Jürgen; Schlieper, Georg; Krüger, Thilo

    2014-08-01

    In chronic kidney disease, vitamin K-dependent proteins, including the calcification inhibitor matrix Gla protein, are largely uncarboxylated indicating that functional vitamin K deficiency may contribute to uremic vascular calcification. Since the effects of uremia on the vitamin K cycle are unknown, we investigated the influence of uremia and vitamin K supplementation on the activity of the vitamin K cycle and extraosseous calcification. Uremia was induced in rats by an adenine-supplemented diet and vitamin K1 or K2 was administered over 4 and 7 weeks. After 4 weeks of adenine diet, the activity of the vitamin K cycle enzyme γ-carboxylase but not the activities of DT-diaphorase or vitamin K epoxide reductase were reduced. Serum levels of undercarboxylated matrix Gla protein increased, indicating functional vitamin K deficiency. There was no light microscopy-detectable calcification at this stage but chemically determined aortic and renal calcium content was increased. Vitamin K treatment reduced aortic and renal calcium content after 4 weeks. Seven weeks of uremia induced overt calcification in the aorta, heart, and kidneys; however, addition of vitamin K restored intrarenal γ-carboxylase activity and overstimulated it in the liver along with reducing heart and kidney calcification. Thus, uremic vitamin K deficiency may partially result from a reduction of the γ-carboxylase activity which possibly contributes to calcification. Pharmacological vitamin K supplementation restored the vitamin K cycle and slowed development of soft tissue calcification in experimental uremia. PMID:24429407

  10. Carboxylation and anaplerosis in neurons and glia.

    Science.gov (United States)

    Hassel, B

    2000-01-01

    Anaplerosis, or de novo formation of intermediates of the tricarboxylic acid (TCA) cycle, compensates for losses of TCA cycle intermediates, especially alpha-ketoglutarate, from brain cells. Loss of alpha-ketoglutarate occurs through release of glutamate and GABA from neurons and through export of glutamine from glia, because these amino acids are alpha-ketoglutarate derivatives. Anaplerosis in the brain may involve four different carboxylating enzymes: malic enzyme, phosphoenopyruvate carboxykinase (PEPCK), propionyl-CoA carboxylase, and pyruvate carboxylase. Anaplerotic carboxylation was for many years thought to occur only in glia through pyruvate carboxylase; therefore, loss of transmitter glutamate and GABA from neurons was thought to be compensated by uptake of glutamine from glia. Recently, however, anaplerotic pyruvate carboxylation was demonstrated in glutamatergic neurons, meaning that these neurons to some extent can maintain transmitter synthesis independently of glutamine. Malic enzyme, which may carboxylate pyruvate, was recently detected in neurons. The available data suggest that neuronal and glial pyruvate carboxylation could operate at as much as 30% and 40-60% of the TCA cycle rate, respectively. Cerebral carboxylation reactions are probably balanced by decarboxylation reactions,, because cerebral CO2 formation equals O2 consumption. The finding of pyruvate carboxylation in neurons entails a major revision of the concept of the glutamine cycle. PMID:11414279

  11. Overexpression of ACC gene from oleaginous yeast Lipomyces starkeyi enhanced the lipid accumulation in Saccharomyces cerevisiae with increased levels of glycerol 3-phosphate substrates.

    Science.gov (United States)

    Wang, Jiancai; Xu, Ronghua; Wang, Ruling; Haque, Mohammad Enamul; Liu, Aizhong

    2016-06-01

    The conversion of acetyl-CoA to malonyl-CoA by acetyl-CoA carboxylase (ACC) is the rate-limiting step in fatty acid biosynthesis. In this study, a gene coding for ACC was isolated and characterized from an oleaginous yeast, Lipomyces starkeyi. Real-time quantitative PCR (qPCR) analysis of L. starkeyi acetyl-CoA carboxylase gene (LsACC1) showed that the expression levels were upregulated with the fast accumulation of lipids. The LsACC1 was co-overexpressed with the glycerol 3-phosphate dehydrogenase gene (GPD1), which regulates lipids biosynthesis by supplying another substrates glycerol 3-phosphate for storage lipid assembly, in the non-oleaginous yeast Saccharomyces cerevisiae. Further, the S. cerevisiae acetyl-CoA carboxylase (ScACC1) was transferred with GPD1 and its function was analyzed in comparison with LsACC1. The results showed that overexpressed LsACC1 and GPD1 resulted in a 63% increase in S. cerevisiae. This study gives new data in understanding of the molecular mechanisms underlying the regulation of fatty acids and lipid biosynthesis in yeasts. PMID:26865376

  12. Photosynthetic Characteristics of Portulaca grandiflora, a Succulent C(4) Dicot : CELLULAR COMPARTMENTATION OF ENZYMES AND ACID METABOLISM.

    Science.gov (United States)

    Ku, S B; Shieh, Y J; Reger, B J; Black, C C

    1981-11-01

    The succulent, cylindrical leaves of the C(4) dicot Portulaca grandiflora possess three distinct green cell types: bundle sheath cells (BSC) in radial arrangement around the vascular bundles; mesophyll cells (MC) in an outer layer adjacent to the BSC; and water storage cells (WSC) in the leaf center. Unlike typical Kranz leaf anatomy, the MC do not surround the bundle sheath tissue but occur only in the area between the bundle sheath and the epidermis. Intercellular localization of photosynthetic enzymes was characterized using protoplasts isolated enzymatically from all three green cell types.Like other C(4) plants, P. grandiflora has ribulose 1,5-bisphosphate carboxylase and the decarboxylating enzyme, NADP(+)-malic enzyme, in the BSC. Unlike other C(4) plants, however, phosphoenolpyruvate carboxylase, pyruvate, Pi dikinase, and NADP(+)-malate dehydrogenase of the C(4) pathway were present in all three green cell types, indicating that all are capable of fixing CO(2) via phosphoenolpyruvate carboxylase and regenerating phosphoenolpyruvate. Other enzymes were about equally distributed between MC and BSC similar to other C(4) plants. The enzyme profile of the WSC was similar to that of the MC but with reduced activity in most enzymes, except mitochondrion-associated enzymes.Intracellular localization of enzymes was studied in organelles partitioned by differential centrifugation using mechanically ruptured mesophyll and bundle sheath protoplasts. Phosphoenolpyruvate carboxylase was a cytosolic enzyme in both cells; whereas, ribulose 1,5-bisphosphate carboxylase and NADP(+)-malic enzyme were exclusively compartmentalized in the bundle sheath chloroplasts. NADP(+)-malate dehydrogenase, pyruvate, Pi dikinase, aspartate aminotransferase, 3-phosphoglycerate kinase, and NADP(+)-triose-P dehydrogenase were predominantly localized in the chloroplasts while alanine aminotransferase and NAD(+)-malate dehydrogenase were mainly present in the cytosol of both cell types. Based

  13. Stimulation of growth and photosynthetic carbon metabolism in Chlamydomonas reinhardtii with triacontanol

    International Nuclear Information System (INIS)

    Treatment of Chlamydomonas reinhardtii Dangeard cells (-, strain N. 90), cultured at 5% CO2, with 1 to 1000 μg/L triacontanol (TRIA) resulted in a 21% to 35% increase in cell density, 7% to 31% increase in total chlorophyll, and 20% to 100% increase in photosynthetic CO2 assimilation. Chlamydomonas cells responded to a broad range of TRIA concentrations that were at least 10-fold above the optimum concentration for higher plants. Octacosanol inhibited the effect of TRIA on photosynthetic CO2 assimilation. TRIA did not alter glycolate excretion, the CO2 compensation point or sensitivity of photosynthetic CO2 assimilation to O2 in Chlamydomonas. Kinetic analysis of TRIA-treated cells showed that the increase in photosynthetic CO2 assimilation was a result of an increase in the whole-cell apparent Vmax. The activity of RuBP carboxylase/oxygenase was significantly higher in cell lysates from TRIA-treated cells than those from control cells. However, quantification of RuBP carboxylase/oxygenase levels by 14CABP binding did not show increased enzyme levels in TRIA-treated cells. Therefore, there was an increase in the specific activity of RuBP carboxylase/oxygenase extracted from Chlamydomonas cells treated with TRIA. TRIA alone had no effect in vitro on the activity of RuBPcarboxylase/oxygenase purified from spinach (Spinacia oleracea) leaves or from cell lysates of Chlamydomonas. RuBP levels were significantly higher in TRIA-treated cells at high and low CO2. Increased RuBP levels in TRIA-treated Chlamydomonas cells were also observed in the absence of CO2 with atmospheres of N2 and 21% O2

  14. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Institute of Scientific and Technical Information of China (English)

    Jun-Fei; Gu; Ming; Qiu; Jian-Chang; Yang

    2013-01-01

    Maize-specific pyruvate orthophosphate dikinase(PPDK) was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase(PCK). The wild-type(WT) cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments,well-watered(WW), moderate drought(MD) and severe drought(SD), were imposed from 9d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities,biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines(PPDK and PCK) were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%,20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments,respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase(PEPC) and carbonic anhydrase(CA) in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to droughttolerance breeding via overexpression of C4enzymes in rice.

  15. Seasonal changes in the expression of energy metabolism-related genes in white adipose tissue and skeletal muscle in female Japanese black bears.

    Science.gov (United States)

    Shimozuru, Michito; Nagashima, Akiko; Tanaka, Jun; Tsubota, Toshio

    2016-01-01

    Bears undergo annual cycles in body mass: rapid fattening in autumn (i.e., hyperphagia), and mass loss in winter (i.e., hibernation). To investigate how Japanese black bears (Ursus thibetanus japonicus) adapt to such extreme physiological conditions, we analyzed changes in the mRNA expression of energy metabolism-related genes in white adipose tissues and skeletal muscle throughout three physiological stages: normal activity (June), hyperphagia (November), and hibernation (March). During hyperphagia, quantitative real-time polymerase chain reaction analysis revealed the upregulation of de novo lipogenesis-related genes (e.g., fatty acid synthase and diacylglycerol O-acyltransferase 2) in white adipose tissue, although the bears had been maintained with a constant amount of food. In contrast, during the hibernation period, we observed a downregulation of genes involved in glycolysis (e.g., glucose transporter 4) and lipogenesis (e.g., acetyl-CoA carboxylase 1) and an upregulation of genes in fatty acid catabolism (e.g., carnitine palmitoyltransferase 1A) in both tissue types. In white adipose tissues, we observed upregulation of genes involved in glyceroneogenesis, including pyruvate carboxylase and phosphoenolpyruvate carboxykinase 1, suggesting that white adipose tissue plays a role in the recycling of circulating free fatty acids via re-esterification. In addition, the downregulation of genes involved in amino acid catabolism (e.g., alanine aminotransferase) and the TCA cycle (e.g., pyruvate carboxylase) indicated a role of skeletal muscle in muscle protein sparing and pyruvate recycling via the Cori cycle. These examples of coordinated transcriptional regulation would contribute to rapid mass gain during the pre-hibernation period and to energy preservation and efficient energy production during the hibernation period. PMID:26880364

  16. Effect of pyruvate kinase gene deletion on the physiology of Corynebacterium glutamicum ATCC13032 under biotin-sufficient non-glutamate-producing conditions: Enhanced biomass production

    Directory of Open Access Journals (Sweden)

    Kazunori Sawada

    2015-12-01

    Full Text Available The effect of pyruvate kinase gene (pyk deletion on the physiology of Corynebacterium glutamicum ATCC13032 was investigated under biotin-sufficient, non-glutamate-producing conditions. In a complex medium containing 100 g/L glucose, a defined pyk deletion mutant, strain D1, exhibited 35% enhancement in glucose consumption rate, 37% increased growth and a 57% reduction in respiration rate compared to the wild-type parent. Significant upregulation of phosphoenolpyruvate (PEP carboxylase and downregulation of PEP carboxykinase activities were observed in the D1 mutant, which may have prevented over-accumulation of PEP caused by the pyk deletion. Moreover, we found a dramatic 63% reduction in the activity of malate:quinone oxidoreductase (MQO in the D1 mutant. MQO, a TCA cycle enzyme that converts malate to oxaloacetate (OAA, constitutes a major primary gate to the respiratory chain in C. glutamicum, thus explaining the reduced respiration rate in the mutant. Additionally, pyruvate carboxylase gene expression was downregulated in the mutant. These changes seemed to prevent OAA over-accumulation caused by the activity changes of PEP carboxylase/PEP carboxykinase. Intrinsically the same alterations were observed in the cultures conducted in a minimal medium containing 20 g/L glucose. Despite these responses in the mutant, metabolic distortion caused by pyk deletion under non-glutamate-producing conditions required amelioration by increased biomass production, as metabolome analysis revealed increased intracellular concentrations of several precursor metabolites for building block formation associated with pyk deletion. These fermentation profiles and metabolic alterations observed in the mutant reverted completely to the wild-type phenotypes in the pyk-complemented strain, suggesting the observed metabolic changes were caused by the pyk deletion. These results demonstrated multilateral strategies to overcome metabolic disturbance caused by pyk

  17. Enhanced tolerance to drought in transgenic rice plants overexpressing C4 photosynthesis enzymes

    Directory of Open Access Journals (Sweden)

    Jun-Fei Gu

    2013-12-01

    Full Text Available Maize-specific pyruvate orthophosphate dikinase (PPDK was overexpressed in rice independently or in combination with the maize C4-specific phosphoenolpyruvate carboxylase (PCK. The wild-type (WT cultivar Kitaake and transgenic plants were evaluated in independent field and tank experiments. Three soil moisture treatments, well-watered (WW, moderate drought (MD and severe drought (SD, were imposed from 9 d post-anthesis till maturity. Leaf physiological and biochemical traits, root activities, biomass, grain yield, and yield components in the untransformed WT and two transgenic rice lines (PPDK and PCK were systematically studied. Compared with the WT, both transgenic rice lines showed increased leaf photosynthetic rate: by 20%–40% under WW, by 45%–60% under MD, and by 80%–120% under SD. The transgenic plants produced 16.1%, 20.2% and 20.0% higher grain yields than WT under the WW, MD and SD treatments, respectively. Under the same soil moisture treatments, activities of phosphoenolpyruvate carboxylase (PEPC and carbonic anhydrase (CA in transgenic plants were 3–5-fold higher than those in WT plants. Compared with ribulose-1,5-bisphosphate carboxylase, activities of PEPC and CA were less reduced under both MD and SD treatments. The transgenic plants also showed higher leaf water content, stomatal conductance, transpiration efficiency, and root oxidation activity and a stronger active oxygen scavenging system than the WT under all soil moisture treatments, especially MD and SD. The results suggest that drought tolerance is greatly enhanced in transgenic rice plants overexpressing C4 photosynthesis enzymes. This study was performed under natural conditions and normal planting density to evaluate yield advantages on a field basis. It may open a new avenue to drought-tolerance breeding via overexpression of C4 enzymes in rice.

  18. The gnyRDBHAL Cluster Is Involved in Acyclic Isoprenoid Degradation in Pseudomonas aeruginosa

    Science.gov (United States)

    Díaz-Pérez, A. L.; Zavala-Hernández, A. N.; Cervantes, C.; Campos-García, J.

    2004-01-01

    Pseudomonas aeruginosa PAO1 mutants affected in the ability to degrade acyclic isoprenoids were isolated with transposon mutagenesis. The gny cluster (for geranoyl), which encodes the enzymes involved in the lower pathway of acyclic isoprenoid degradation, was identified. The gny cluster is constituted by five probable structural genes, gnyDBHAL, and a possible regulatory gene, gnyR. Mutations in the gnyD, gnyB, gnyA, or gnyL gene caused inability to assimilate acyclic isoprenoids of the citronellol family of compounds. Transcriptional analysis showed that expression of the gnyB gene was induced by citronellol and repressed by glucose, whereas expression of the gnyR gene had the opposite behavior. Western blot analysis of citronellol-grown cultures showed induction of biotinylated proteins of 70 and 73 kDa, which probably correspond to 3-methylcrotonoyl-coenzyme A (CoA) carboxylase and geranoyl-CoA carboxylase (GCCase) alpha subunits, respectively. The 73-kDa biotinylated protein, identified as the α-GCCase subunit, is encoded by gnyA. Intermediary metabolites of the isoprenoid pathway, citronellic and geranic acids, were shown to accumulate in gnyB and gnyA mutants. Our data suggest that the protein products encoded in the gny cluster are the β and α subunits of geranoyl-CoA carboxylase (GnyB and GnyA), the citronelloyl-CoA dehydrogenase (GnyD), the γ-carboxygeranoyl-CoA hydratase (GnyH), and the 3-hydroxy-γ-carboxygeranoyl-CoA lyase (GnyL). We conclude that the gnyRDBHAL cluster is involved in isoprenoid catabolism. PMID:15345388

  19. AcEST: BP921766 [AcEST

    Lifescience Database Archive (English)

    Full Text Available carboxylase OS=Petunia hybrida G... 80 3e-15 sp|Q42521|DCE1_ARATH Glutamate decarboxylase 1 OS=Arabidopsis t...h... 79 7e-15 sp|Q42472|DCE2_ARATH Glutamate decarboxylase 2 OS=Arabidopsis th......L 452 >sp|Q07346|DCE_PETHY Glutamate decarboxylase OS=Petunia hybrida GN=GAD PE=1 SV=1 Length = 500 Score = ...Query: 186 VAVAIAQ 206 +AVA Q Sbjct: 455 LAVAEEQ 461 >sp|Q42521|DCE1_ARATH Glutamate decarboxylase 1 OS=Arab...SE 463 >sp|Q42472|DCE2_ARATH Glutamate decarboxylase 2 OS=Arabidopsis thaliana GN

  20. Diurnal changes of Rubisco in response to elevated CO2, temperature and nitrogen in wheat grown under temperature gradient tunnels.

    OpenAIRE

    Pérez, P.; Morcuende, R.; Martín del Molino, I.; Martínez-Carrasco, R.

    2005-01-01

    Growth at elevated CO2 and temperature often leads to decreased Rubisco activity. We investigated the effects of increased CO2, temperature and nitrogen on the diurnal changes in the control of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) activity in wheat (Triticum aestivum L.). Spring wheat was grown at ambient and 700 μmol mol-1 CO2, under ambient and 4 ºC warmer temperatures, and with two levels of nitrogen supply in field tunnels in a Mediterranean environment...

  1. [Advances in research on CO2 concentrating mechanism of green algae].

    Science.gov (United States)

    Xia, Jianrong; Gao, Kunshan

    2002-11-01

    Unicellular green algae plays a key role in freshwater ecosystem, which possesses a CO2 concentrating mechanism that can increase the level of CO2 at the active site of ribulose bisphosphate carboxylase-oxygenase (Rubisco) by actively transporting inorganic carbon when adapted to low CO2 concentration. The mechanism results in an increase in photosynthetic rate, and a decrease in photorespiration. This mechanism and its environmental regulation such as light, temperature, CO2 concentration and nutrient are reviewed in this paper to enhance further studies on response of phytoplankton to elevated atmospheric CO2 concentration in China. PMID:12625019

  2. Proposed guidelines for the diagnosis and management of methylmalonic and propionic acidemia

    DEFF Research Database (Denmark)

    Baumgartner, Matthias R; Hörster, Friederike; Dionisi-Vici, Carlo;

    2014-01-01

    :100'000 -150,000. Patients present either shortly after birth with acute deterioration, metabolic acidosis and hyperammonemia or later at any age with a more heterogeneous clinical picture, leading to early death or to severe neurological handicap in many survivors. Mental outcome tends to be worse in PA and......Methylmalonic and propionic acidemia (MMA/PA) are inborn errors of metabolism characterized by accumulation of propionic acid and/or methylmalonic acid due to deficiency of methylmalonyl-CoA mutase (MUT) or propionyl-CoA carboxylase (PCC). MMA has an estimated incidence of ~ 1: 50,000 and PA of ~ 1...

  3. Transit peptides of nuclear-encoded chloroplast proteins share a common amino acid framework.

    OpenAIRE

    Karlin-Neumann, G A; Tobin, E M

    1986-01-01

    We have identified three major blocks of amino acid homology shared by the transit peptides of two nuclear-encoded chloroplast proteins, the light-harvesting chlorophyll a/b-protein (LHCP) II of the thylakoid membrane and the small subunit (SSU) of ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO) of the stroma. These previously unrecognized homology blocks lie at the beginning, middle and end of both transit sequences, and are separated by differing lengths of unshared (interblock) s...

  4. Molecular characterization of a deep-sea methanotrophic mussel symbiont that carries a RuBisCO gene

    OpenAIRE

    Elsaied, Hosam Easa; Kaneko, Ryo; Naganuma, Takeshi

    2006-01-01

    In our previous investigation on the genes of 1,5-bisphosphate carboxylase/oxygenase (RuBisCO; EC 4.1.1.39) in deep-sea chemoautotrophic and methanotrophic endosymbioses, the gene encoding the large subunit of RuBisCO form I (cbbL) had been detected in the gill of a mussel belonging to the genus Bathymodiolus from a western Pacific back-arc hydrothermal vent. This study further revealed the symbiont source of the RuBisCO cbbL gene along with the genes of 16S ribosomal RNA (16S rDNA), particul...

  5. Effect of heavy metals on the carbon and nitrogen ratio in Avicennia marina from polluted and unpolluted regions

    Digital Repository Service at National Institute of Oceanography (India)

    Yadav, A.; Ram, A.; Majithiya, D.; Salvi, S.; Sonavane, S.; Kamble, A.; Ghadigaonkar, S.; JiyalalRam, M.J.; Gajbhiye, S.N.

    al., 2010). (Ribulose-1, 5-biphosphate carboxylase/oxygenase — an enzyme involved in the first major step of carbon fixation), inhibition inBut at high concentrations even essential metals are strongly toxic and photo-system II activity, and electron... transport. Changes in photosyn-of the primary electron donor in photo-system I of plants and plays an important role in CO2 assimilation and ATP synthesis. Several enzymes containing Zn are required in the formation of carbohydrates in plants. Manganese...

  6. AcEST: DK948555 [AcEST

    Lifescience Database Archive (English)

    Full Text Available ctive receptor kinase RLK902 O... 33 1.7 sp|P55195|PUR6_VIGAC Phosphoribosylaminoimidazole carboxylas...33 GIVC 644 G++C Sbjct: 64 GVLC 67 >sp|P55195|PUR6_VIGAC Phosphoribosylaminoimidazole carboxylase, chloroplastic (Fragment) OS=Vigna...ctive receptor kinase At2g26730 OS=Arabidopsis thaliana Align length 65 Score (bit) 38.1 ...ctive receptor kinase At2g26730 OS=Arabidopsis thaliana GN=At2...16_ARATH Probable receptor kinase At5g05160 OS=Arabidopsis thaliana GN=At5g05160 PE=1 SV=1 Length = 640 Scor

  7. (Anthracen-9-yl(piperidin-1-ylmethanone

    Directory of Open Access Journals (Sweden)

    Hua-You Hu

    2008-11-01

    Full Text Available The title compound, C20H19NO, is a substructure of CP-640186, a potent inhibitor of mammalian acetyl-coenzyme A carboxylases. In the crystal structure, the amide group forms a dihedral angle of 87.0 (1° with the plane of the anthracene unit and the piperidine ring adopts a chair conformation. Molecules are arranged into layers parallel to (100 and adjacent anthracene units within layers form dihedral angles of 13.2 (1°. C—H...O interactions from the piperidine rings to the C=O group of the amide are observed between layers.

  8. Vitamin K Induces Osteoblast Differentiation through Pregnane X Receptor-Mediated Transcriptional Control of the Msx2 Gene▿

    OpenAIRE

    Igarashi, Mamoru; Yogiashi, Yoshiko; Mihara, Masatomo; Takada, Ichiro; Kitagawa, Hirochika; Kato, Shigeaki

    2007-01-01

    Vitamin K is a fat-soluble vitamin that serves as a coenzyme for vitamin K-dependent carboxylase. Besides its canonical action, vitamin K binds to the steroid and xenobiotic receptor (SXR)/pregnane X receptor (PXR) and modulates gene transcription. To determine if the osteoprotective action of vitamin K is the result of the PXR/SXR pathway, we screened by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis the PXR/SXR target genes in an osteoblastic cell line (MC3T3-E1) ...

  9. Salicylic acid alleviates adverse effects of heat stress on photosynthesis through changes in proline production and ethylene formation

    OpenAIRE

    Khan, M. Iqbal R.; Iqbal, Noushina; Masood, Asim; Per, Tasir S.; Khan, Nafees A.

    2013-01-01

    We investigated the potential of salicylic acid (SA) in alleviating the adverse effects of heat stress on photosynthesis in wheat (Triticum aestivum L.) cv WH 711. Activity of ribulose 1,5-bisphosphate carboxylase (Rubisco), photosynthetic-nitrogen use efficiency (NUE), and net photosynthesis decreased in plants subjected to heat stress (40°C for 6 h), but proline metabolism increased. SA treatment (0.5 mM) alleviated heat stress by increasing proline production through the increase in γ-glut...

  10. Fatty acid metabolism: target for metabolic syndrome

    OpenAIRE

    Wakil, Salih J.; Abu-Elheiga, Lutfi A.

    2009-01-01

    Fatty acids are a major energy source and important constituents of membrane lipids, and they serve as cellular signaling molecules that play an important role in the etiology of the metabolic syndrome. Acetyl-CoA carboxylases 1 and 2 (ACC1 and ACC2) catalyze the synthesis of malonyl-CoA, the substrate for fatty acid synthesis and the regulator of fatty acid oxidation. They are highly regulated and play important roles in the energy metabolism of fatty acids in animals, including humans. They...

  11. Yeast Interacting Proteins Database: YDR271C, YOR128C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YDR271C - Dubious open reading frame unlikely to encode a protein, based on availab...ait (0) 2 54 2 2 0 0 0 0 0 - - - - - 0 0 11 - Show YDR271C Bait ORF YDR271C Bait gene name - Bait description Dubious open reading...is bait as bait (1) Rows with this bait as prey (0) YOR128C ADE2 Phosphoribosylaminoimidazole carboxylase, catalyzes a step in...e ADE2 Prey description Phosphoribosylaminoimidazole carb...ture shared by bait and prey 2 Literature sharing score 2 CuraGen (0 or 1) 0 S. F

  12. Astrocytic control of biosynthesis and turnover of the neurotransmitters glutamate and GABA

    DEFF Research Database (Denmark)

    Schousboe, Arne; Bak, Lasse Kristoffer; Waagepetersen, Helle S

    2013-01-01

    Glutamate and GABA are the quantitatively major neurotransmitters in the brain mediating excitatory and inhibitory signaling, respectively. These amino acids are metabolically interrelated and at the same time they are tightly coupled to the intermediary metabolism including energy homeostasis....... Astrocytes play a pivotal role in the maintenance of the neurotransmitter pools of glutamate and GABA since only these cells express pyruvate carboxylase, the enzyme required for de novo synthesis of the two amino acids. Such de novo synthesis is obligatory to compensate for catabolism of glutamate and GABA...

  13. Quantitative Measurement of Plasma 3-Hydroxyisovaleryl Carnitine by LC-MS/MS as a Novel Biomarker of Biotin Status in Humans

    OpenAIRE

    Horvath, Thomas D.; Stratton, Shawna L; Bogusiewicz, Anna; Pack, Lindsay; Moran, Jeffery; Mock, Donald M

    2010-01-01

    An increased plasma concentration of 3-hydroxyisovaleryl carnitine (3HIA-carnitine) results from impairment in the leucine catabolic pathway at the conversion of 3-methyl-crotonyl-CoA to 3-methylglutaconyl-CoA. The impairment is caused by reduced activity of the biotin-dependent enzyme 3-methylcrotonyl-CoA carboxylase. Here, we describe an LC-MS/MS method for the quantitation of 3HIA-carnitine in plasma and present preliminary evidence validating plasma 3HIA-carnitine as a novel biomarker of ...

  14. Changes in the photosynthetic activity and transport os assimilates during ontogenesis of buckwheat grown from irradiated seeds

    International Nuclear Information System (INIS)

    It was established that the rate of CO2 fixation decreased during the photosynthesis particularly at the initial stages of the growth and development of buckwheat plants grown from γ-irradiated (100 Gy) seeds. It was shown that the rate of the photosynthesis and, to a lesser extent, the activity of the principle enzyme of the recovery pentosephosphate cycle, RDP-carboxylase, decreased. γ-radiation affected the pathway of carbon in the photosynthesis, i.e. somewhat increased the level of mobile sugars in a free area of the leaf mesophyll and, at the same time, decreased the content of aminoacids and organic acids

  15. Nitrosomonas communis strain YNSRA, an ammonia-oxidizing bacterium, isolated from the reed rhizoplane in an aquaponics plant.

    Science.gov (United States)

    Tokuyama, Tatsuaki; Mine, Atsusi; Kamiyama, Kaoru; Yabe, Ryuichi; Satoh, Kazuo; Matsumoto, Hirotoshi; Takahashi, Reiji; Itonaga, Koji

    2004-01-01

    An ammonia-oxidizing bacterium (strain YNSRA) was isolated from the rhizoplane of the reed (Phragmites communis) used in an aquaponics plant which is a wastewater treatment plant. Strain YNSRA was identified as Nitrosomonas communis by taxonomic studies. The hydroxylamine-cytochrome c reductase (HCR) of strain YNSRA was found to have a higher activity (25.60 u/mg) than that of Nitrosomonas europaea ATCC25978T (8.94 u/mg). Ribulose-1,5-bisphosphate carboxylase (RubisCO) activity was detected at very low levels in strain YNSRA, whereas strain ATCC25978T had definite activity. PMID:16233712

  16. Biotin Carboxyl Carrier Protein in Barley Chloroplast Membranes

    DEFF Research Database (Denmark)

    Kannangara, C. G.; Jense, C J

    1975-01-01

    Biotin localized in barley chloroplast lamellae is covalently bound to a single protein with an approximate molecular weight of 21000. It contains one mole of biotin per mole of protein and functions as a carboxyl carrier in the acetyl-CoA carboxylase reaction. The protein was obtained by...... solubilization of the lamellae in phenol/acetic acid/8 M urea. Feeding barley seedlings with [14C]-biotin revealed that the vitamin is not degraded into respiratory substrates by the plant, but is specifically incorporated into biotin carboxyl carrier protein....

  17. Yeast Interacting Proteins Database: YGL154C, YOR128C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available his bait as prey (0) Prey ORF YOR128C Prey gene name ADE2 Prey description Phosphoribosylaminoimidazole carboxyla...R128C ADE2 Phosphoribosylaminoimidazole carboxylase, catalyzes a step in the 'de novo' purine nucleotid...rts inactive apo-form of Lys2p (alpha-aminoadipate reductase) into catalytically active holo-form by posttransla...tional addition of phosphopantetheine Rows with this bait as bait (2) Rows with this bait as prey (0) YO...154C Bait ORF YGL154C Bait gene name LYS5 Bait description Phosphopantetheinyl tr

  18. Dicty_cDB: SSG860 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available uen... 33 4.8 AP006716_1892( AP006716 |pid:none) Staphylococcus haemolyticus JCS... 33 4.8 (Q4L574) RecName: Full=Phosphoribosylami...noimidazole carboxylase ... 33 4.8 protein update 2009. 7. 7 PSORT psg: 0.98 gvh: 0.8...GAFLPGCFWCPWSSKLTREIKI*tirvklnys*lnliklnt*ifnnkvy*tkvfik Translated Amino Acid sequence (All Frames) Frame A...AAGTTTATTAAACAAAAGTTTTTATAAAA A sequence update 1997.12. 9 Translated Amino Acid sequence ql*ttn*kln*KMKLLFV...IRKRPESYNPKYSFILDPDTITFFSMAIEVCDASTIYVEDHL DEACGAFLPGCFWCPWSSKLTREIKI*tirvklnys*lnliklnt*ifnnkvy*tkvfik Frame B: nykqqiknsikk*nyyl

  19. AMPK Activation Affects Glutamate Metabolism in Astrocytes

    DEFF Research Database (Denmark)

    Voss, Caroline Marie; Pajęcka, Kamilla; Stridh, Malin H;

    2015-01-01

    acid (TCA) cycle was studied using high-performance liquid chromatography analysis supplemented with gas chromatography-mass spectrometry technology. It was found that AMPK activation had profound effects on the pathways involved in glutamate metabolism since the entrance of the glutamate carbon...... affected by a reduction of the flux of glutamate derived carbon through the malic enzyme and pyruvate carboxylase catalyzed reactions. Finally, it was found that in the presence of glutamate as an additional substrate, glucose metabolism monitored by the use of tritiated deoxyglucose was unaffected by AMPK...

  20. The Effect of Prolonged Fasting on Total Lipid Synthesis and Enzyme Activities in the Liver of the European Eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Abraham, S. A.; Hansen, Heinz Johs. Max; Hansen, F.N.

    1984-01-01

    reduced (acetyl-CoA carboxylase decreased 2-fold and fatty acid synthetase declined 5-fold); others remained unchanged (G-6-P dehydrogenase, 6-phosphogluconate dehydrogenase, .alpha.-glycerol phosphate dehydrogenase as well as malic enzyme and ATP-citrate lyase). The optimum temperature for measuring both......The extent of fatty acid synthesis from [1-14C]acetate in liver slices was reduced 6-fold when eels were fasted for 1-7 wk and 20-fold when fasted for 39 wk, thereafter hepatic lipogenesis seemed to remain constant for up to 95 wk of fasting. After a 1-3 wk fast some hepatic enzyme activities were...

  1. Mineral Content and Biochemical Variables of Aloe vera L. under Salt Stress

    OpenAIRE

    Bernardo Murillo-Amador; Miguel Víctor Córdoba-Matson; Jorge Arnoldo Villegas-Espinoza; Luis Guillermo Hernández-Montiel; Enrique Troyo-Diéguez; José Luis García-Hernández

    2014-01-01

    Despite the proven economic importance of Aloe vera, studies of saline stress and its effects on the biochemistry and mineral content in tissues of this plant are scarce. The objective of this study was to grow Aloe under NaCl stress of 0, 30, 60, 90 and 120 mM and compare: (1) proline, total protein, and enzyme phosphoenolpyruvate carboxylase (PEP-case) in chlorenchyma and parenchyma tissues, and (2) ion content (Na, K, Ca, Mg, Cl, Fe, P. N, Zn, B, Mn, and Cu) in roots, stems, leaves and spr...

  2. Detecting ALS and ACCase herbicide tolerant accession of Echinochloa oryzoides (Ard.) Fritsch. in rice (Oryza sativa L.) fields

    DEFF Research Database (Denmark)

    Altop, Emine Kaya; Mennan, Husrev; Streibig, Jens Carl; Budak, Unal; Ritz, Christian

    2014-01-01

    -sodium) and acetyl CoA carboxylase (cyhalofob-butyl) inhibiting herbicides. Comparison of 95% lower confidence intervals of ED90 derived from log-logistic dose-response curves, and twice the recommended field rates of the herbicides showed some, but not distinct separation of susceptible and tolerant...... bispyribac-sodium) at recommended field rates; and 38% were not controlled by the ACCase Inhibitor (cyhalofob-butyl) at twice the field rates. The effective response level of ED90 resulted in 64 and 14 tolerant accessions to ALS and ACCase, respectively. Fourteen accessions showed multiple resistances to ALS...

  3. Influence of metabolites from the glycolate on the intensity of photosynthesis in C3 and C4-plants

    International Nuclear Information System (INIS)

    The experiments described are the result of the influence of photorespiratory metabolites on the intensity of photosynthesis in leaf discs from pisum (C3) and maize (C4) plants. Pisum protoplasts are also used. The discs are dried and exposed in a closed system in an atmosphere of 14CO2. Fixation of 14CO2 is determined in the reaction medium. The total radioactivity is measured. The inhibition of glycolate synthesis, photorespiration is accompanied by a rise in net photosynthesis. The positive effect of glycolic acid on photosynthesis is undoubtedly determined by the established stimulating action on the enzyme RuBPC (ribulosediphosphate carboxylase). (author)

  4. Photosynthetic flexibility in maize exposed to salinity and shade

    OpenAIRE

    Sharwood, Robert E.; Sonawane, Balasaheb V.; Ghannoum, Oula

    2014-01-01

    C4 photosynthesis involves a close collaboration of the C3 and C4 metabolic cycles across the mesophyll and bundle-sheath cells. This study investigated the coordination of C4 photosynthesis in maize plants subjected to two salinity (50 and 100mM NaCl) treatments and one shade (20% of full sunlight) treatment. Photosynthetic efficiency was probed by combining leaf gas-exchange measurements with carbon isotope discrimination and assaying the key carboxylases [ribulose-1,5-bisphosphate carboxyl...

  5. Photosynthetic flexibility in maize exposed to salinity and shade.

    Science.gov (United States)

    Sharwood, Robert E; Sonawane, Balasaheb V; Ghannoum, Oula

    2014-07-01

    C4 photosynthesis involves a close collaboration of the C3 and C4 metabolic cycles across the mesophyll and bundle-sheath cells. This study investigated the coordination of C4 photosynthesis in maize plants subjected to two salinity (50 and 100mM NaCl) treatments and one shade (20% of full sunlight) treatment. Photosynthetic efficiency was probed by combining leaf gas-exchange measurements with carbon isotope discrimination and assaying the key carboxylases [ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC)] and decarboxylases [nicotinamide adenine dinucleotide phosphate malic enzyme (NADP-ME) and phosphoenolpyruvate carboxykinase (PEP-CK)] operating in maize leaves. Generally, salinity inhibited plant growth and photosynthesis to a lesser extent than shade. Salinity reduced photosynthesis primarily by reducing stomatal conductance and secondarily by equally reducing Rubisco and PEPC activities; the decarboxylases were inhibited more than the carboxylases. Salinity increased photosynthetic carbon isotope discrimination (Δp) and reduced leaf dry-matter carbon isotope composition ((13)δ) due to changes in p i/p a (intercellular to ambient CO2 partial pressure), while CO2 leakiness out of the bundle sheath (ϕ) was similar to that in control plants. Acclimation to shade was underpinned by a greater downregulation of PEPC relative to Rubisco activity, and a lesser inhibition of NADP-ME (primary decarboxylase) relative to PEP-CK (secondary decarboxylase). Shade reduced Δp and ɸ without significantly affecting leaf (13)δ or p i/p a relative to control plants. Accordingly, shade perturbed the balance between the C3 and C4 cycles during photosynthesis in maize, and demonstrated the flexible partitioning of C4 acid decarboxylation activity between NADP-ME and PEP-CK in response to the environment. This study highlights the need to improve our understanding of the links between leaf (13)δ and photosynthetic Δp, and

  6. Effect of salicylic acid on the growth photosynthesis and carbohydrate metabolism in salt stressed maize plants

    International Nuclear Information System (INIS)

    Aqueous solutions of salicylic acid as a spray to Na CI-treated corn (Zea mays L,) significantly increased the growth of shoots and roots as measured after seven days of treatment. Spraying of salicylic acid caused significant increases in the activity of both ribulose 1,5 bisphosphate carboxylase (rubisco) enzyme and photosynthetic pigments. Moreover, salicylic acid treatment induced high values of soluble carbohydrate fractions in salt stressed plants as compared with salicylic acid treated samples. These data suggest that salicylic acid might improve the growth pattern of NaCl-treated maize plants via increasing the rate of photosynthesis and carbohydrate metabolism

  7. Dicty_cDB: Contig-U11114-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ktdpqislryn qmlvpaqvqplgiemideltkttnaileltkhktlqqdnkilqhfvsirrtfmdpinyiq vetlkrlrstqkpdgtnddadpilidtliitfngi..............................done Score E Sequences producing significant alignments: (bits) Value N ( BJ424127 ) Dictyosteli...6e-61 AY663387_1( AY663387 |pid:none) Lupinus albus phosphoenolpyruvate ... 140 9e-61 AF495586_1( AF495586 |pid:none) Setaria itali...ergonella cuspidata partial m... 139 4e-59 AK065029_1( AK065029 |pid:none) Oryza sativa Japonica...me: Full=Phosphoenolpyruvate carboxylase; ... 143 9e-59 AK317277_1( AK317277 |pid:none) Arabidopsis thali

  8. PHYLOGENETIC ANALYSIS AMONG FOUR SECTIONS OF GENUS DENDROBIUM SW. (ORCHIDACEAE IN PENINSULAR MALAYSIA USING RBCL SEQUENCE DATA

    Directory of Open Access Journals (Sweden)

    Maryam Moudi

    2013-06-01

    Full Text Available Phylogenetic analysis using chloroplast DNA, the ribulose-bisphosphate carboxylase gene (rbcL, was conducted to examine relationship among four sections of the genus Dendrobium (Orchidaceae: Aporum, Crumenata, Strongyle, and Bolbidium in Peninsular Malaysia. Classifications based on morphological characters have not been able to clearly divide these four sections, therefore deeper and detailed analyses are required to ascertain their status. In this study, the phylogenetic relationships among species of the four sections were investigated to clarify their relations either to lump them into one section or reduce them into two.

  9. Ectomycorrhizal association of three Lactarius species with Carpinus and Quercus trees in a Mexican montane cloud forest.

    Science.gov (United States)

    Lamus, Valentina; Montoya, Leticia; Aguilar, Carlos J; Bandala, Victor M; Ramos, David

    2012-01-01

    Ectomycorrhizal (EM) fungi are being monitored in the Santuario del Bosque de Niebla in the central region of Veracruz (eastern Mexico). Based on the comparison of DNA sequences (ITS rDNA) of spatiotemporally co-occurring basidiomes and EM root tips, we discovered the EM symbiosis of Lactarius indigo, L. areolatus and L. strigosipes with Carpinus caroliniana, Quercus xalapensis and Quercus spp. The host of the EM tips was identified by comparison of the large subunit of the ribulose-bisphosphate carboxylase gene (rbcL). Descriptions coupled with photographs of ectomycorrhizas and basidiomes are presented. PMID:22675052

  10. ACACβ gene (rs2268388) and AGTR1 gene (rs5186) polymorphism and the risk of nephropathy in Asian Indian patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Shah, Viral N; Cheema, Balneek Singh; Sharma, Rajni; Khullar, Madhu; Kohli, Harbir Singh; Ahluwalia, Tarun Veer Singh; Mohan, Viswanathan; Bhansali, Anil

    Patients with type 2 diabetes (T2DM) are usually obese and concurrent obesity results into activation of the renin-angiotensin-system (RAS) which is a risk factor for diabetic nephropathy (DN). Gene-gene interaction between acetyl-coenzymeA carboxylase beta (ACACβ) gene, which is involved in fatty...... acid metabolism and angiotensin II receptors (AGTR1) gene, which mediates RAS proteins actions on renal tissue, polymorphism with DN have not been studied earlier. The present study was designed with the aim to examine the association of an ACACβ (rs2268388) and AGTR1 (rs5186) gene polymorphism with...

  11. Photosynthetic carbon fixation characteristics of fruiting structures of Brassica campestris L

    International Nuclear Information System (INIS)

    Activities of key enzymes of the Calvin cycle and C4 metabolism, rates of CO2 fixation, and the initial products of photosynthetic 14CO2 fixation were determined in the podwall, seed coat (fruiting structures), and the subtending leaf (leaf below a receme) of Brassica campestris L. cv Toria. Compared to activities of ribulose-1,5-bisphosphate carboxylase and other Calvin cycle enzymes, e.g. NADP-glyceraldehyde-3-phosphate-dehydrogenase and ribulose-5-phosphate kinase, the activities of phosphoenol pyruvate carboxylase and other enzymes of C4 metabolism, viz. NADP-malate dehydrogenase, NADP-malic enzyme, glutamate pyruvate transaminase, and glutamate oxaloacetate transaminase, were generally much higher in seed than in podwall and leaf. Podwall and leaf were comparable to each other. Pulse-chase experiments showed that in seed the major product of 14CO2 assimilation was malate (in short time), whereas in podwall and leaf, the label initially appeared in 3-PGA. With time, the label moved to sucrose. In contrast to legumes, Brassica pods were able to fix net CO2 during light. However, respiratory losses were very high during the dark period

  12. Activation of Acetone and Other Simple Ketones in Anaerobic Bacteria.

    Science.gov (United States)

    Heider, Johann; Schühle, Karola; Frey, Jasmin; Schink, Bernhard

    2016-01-01

    Acetone and other ketones are activated for subsequent degradation through carboxylation by many nitrate-reducing, phototrophic, and obligately aerobic bacteria. Acetone carboxylation leads to acetoacetate, which is subsequently activated to a thioester and degraded via thiolysis. Two different types of acetone carboxylases have been described, which require either 2 or 4 ATP equivalents as an energy supply for the carboxylation reaction. Both enzymes appear to combine acetone enolphosphate with carbonic phosphate to form acetoacetate. A similar but more complex enzyme is known to carboxylate the aromatic ketone acetophenone, a metabolic intermediate in anaerobic ethylbenzene metabolism in denitrifying bacteria, with simultaneous hydrolysis of 2 ATP to 2 ADP. Obligately anaerobic sulfate-reducing bacteria activate acetone to a four-carbon compound as well, but via a different process than bicarbonate- or CO2-dependent carboxylation. The present evidence indicates that either carbon monoxide or a formyl residue is used as a cosubstrate, and that the overall ATP expenditure of this pathway is substantially lower than in the known acetone carboxylase reactions. PMID:26958851

  13. Saponins, especially platycodin D, from Platycodon grandiflorum modulate hepatic lipogenesis in high-fat diet-fed rats and high glucose-exposed HepG2 cells.

    Science.gov (United States)

    Hwang, Yong Pil; Choi, Jae Ho; Kim, Hyung Gyun; Khanal, Tilak; Song, Gye Young; Nam, Myoung Soo; Lee, Hyun-Sun; Chung, Young Chul; Lee, Young Chun; Jeong, Hye Gwang

    2013-03-01

    AMP-activated protein kinase (AMPK) plays a central role in controlling hepatic lipid metabolism through modulating the downstream acetyl CoA carboxylase (ACC) and sterol regulatory element-binding protein-1c (SREBP-1c) pathway. Saponins, particularly platycodin D, from the roots of Platycodon grandiflorum (Changkil saponins, CKS) have a variety of pharmacological properties, including antioxidant and hepatoprotective properties. The aim of this study was to investigate the effects of CKS on hepatic lipogenesis and on the expression of genes involved in lipogenesis, and the mechanisms involved. CKS attenuated fat accumulation and the induction of the lipogenic genes encoding SREBP-1c and fatty acid synthase in the livers of HFD-fed rats and in steatotic HepG2 cells. Blood biochemical analyses and histopathological examinations showed that CKS prevented liver injury. CKS and platycodin D each increased the phosphorylation of AMPK and acetyl-CoA carboxylase in HFD-fed rats and HepG2 cells. The use of specific inhibitors showed that platycodin D activated AMPK via SIRT1/CaMKKβ in HepG2 cells. This study demonstrates that CKS or platycodin D alone can regulate hepatic lipogenesis via an AMPK-dependent signalling pathway. PMID:23319015

  14. Holocarboxylase synthetase deficiency pre and post newborn screening

    Directory of Open Access Journals (Sweden)

    Taraka R. Donti

    2016-06-01

    Full Text Available Holocarboxylase synthetase deficiency is an autosomal recessive disorder of biotin metabolism resulting in multiple carboxylase deficiency. The typical presentation described in the medical literature is of neonatal onset within hours to weeks of birth with emesis, hypotonia, lethargy, seizures, metabolic ketolactic acidosis, hyperammonemia, developmental delay, skin rash and alopecia. The condition is screened for by newborn screening (NBS tandem mass spectroscopy by elevated hydroxypentanoylcarnitine on dried blood spots. Urine organic acid profile may demonstrate elevated lactic, 3-OH isovaleric, 3-OH propionic, 3-MCC, methylcitric acids, and tiglylglycine consistent with loss of function of the above carboxylases. Here we describe a cohort of patients, 2 diagnosed pre-NBS and 3 post-NBS with broad differences in initial presentation and phenotype. In addition, prior to the advent of NBS, there are isolated reports of late-onset holocarboxylase synthetase deficiency in the medical literature, which describe patients diagnosed between 1 and 8 years of life, however to our knowledge there are no reports of late-onset HCLS being missed by NBS. Also we report two cases, each with novel pathogenic variants HCLS, diagnosed at age 3 years and 21 months respectively. The first patient had a normal newborn screen whilst the second had an abnormal newborn screen but was misdiagnosed as 3-methylcrotonylcarboxylase (3-MCC deficiency and subsequently lost to follow-up until they presented again with severe metabolic acidosis.

  15. Holocarboxylase synthetase deficiency pre and post newborn screening.

    Science.gov (United States)

    Donti, Taraka R; Blackburn, Patrick R; Atwal, Paldeep S

    2016-06-01

    Holocarboxylase synthetase deficiency is an autosomal recessive disorder of biotin metabolism resulting in multiple carboxylase deficiency. The typical presentation described in the medical literature is of neonatal onset within hours to weeks of birth with emesis, hypotonia, lethargy, seizures, metabolic ketolactic acidosis, hyperammonemia, developmental delay, skin rash and alopecia. The condition is screened for by newborn screening (NBS) tandem mass spectroscopy by elevated hydroxypentanoylcarnitine on dried blood spots. Urine organic acid profile may demonstrate elevated lactic, 3-OH isovaleric, 3-OH propionic, 3-MCC, methylcitric acids, and tiglylglycine consistent with loss of function of the above carboxylases. Here we describe a cohort of patients, 2 diagnosed pre-NBS and 3 post-NBS with broad differences in initial presentation and phenotype. In addition, prior to the advent of NBS, there are isolated reports of late-onset holocarboxylase synthetase deficiency in the medical literature, which describe patients diagnosed between 1 and 8 years of life, however to our knowledge there are no reports of late-onset HCLS being missed by NBS. Also we report two cases, each with novel pathogenic variants HCLS, diagnosed at age 3 years and 21 months respectively. The first patient had a normal newborn screen whilst the second had an abnormal newborn screen but was misdiagnosed as 3-methylcrotonylcarboxylase (3-MCC) deficiency and subsequently lost to follow-up until they presented again with severe metabolic acidosis. PMID:27114915

  16. Observations of the uptake of carbonyl sulfide (COS by trees under elevated atmospheric carbon dioxide concentrations

    Directory of Open Access Journals (Sweden)

    L. Sandoval-Soto

    2012-02-01

    Full Text Available Global change affects ecosystems to adapt to elevated atmospheric concentrations of carbon dioxide (CO2. We understand that carbonyl sulfide (COS, a trace gas which is involved in building up the stratospheric sulfate aerosol layer, is taken up by vegetation with the same triad of the enzmyes which are metabolizing the CO2, i.e. Ribulose-1,5-bisphosphate Carboxylase-Oxygenase (Rubisco, Phosphoenolpyruvate Carboxylase (PEP-Co and carbonic anhydrase (CA. Therefore, we discuss a physiological/biochemical adaptation of these enzymes to affect the sink strength of vegetation for COS. We investigated the adaption of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers under elevated CO2 and determined the exchange characteristics and the content of CA after a 1–2 yr period of adaption from 350 ppm to 800 ppm CO2. We could demonstrate that the COS compensation point, the CA activity and the deposition velocities may change and cause a decrease of the COS uptake by plant ecosystems. As a consequence, the atmospheric COS level may rise leading to higher input of this trace gas into the stratosphere and causing a higher energy reflection by the stratospheric sulfur aerosol into space, thus counteracting the direct radiative forcing by the tropospheric COS.

  17. Bacterial microcompartments as metabolic modules for plant synthetic biology.

    Science.gov (United States)

    Gonzalez-Esquer, C Raul; Newnham, Sarah E; Kerfeld, Cheryl A

    2016-07-01

    Bacterial microcompartments (BMCs) are megadalton-sized protein assemblies that enclose segments of metabolic pathways within cells. They increase the catalytic efficiency of the encapsulated enzymes while sequestering volatile or toxic intermediates from the bulk cytosol. The first BMCs discovered were the carboxysomes of cyanobacteria. Carboxysomes compartmentalize the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) with carbonic anhydrase. They enhance the carboxylase activity of RuBisCO by increasing the local concentration of CO2 in the vicinity of the enzyme's active site. As a metabolic module for carbon fixation, carboxysomes could be transferred to eukaryotic organisms (e.g. plants) to increase photosynthetic efficiency. Within the scope of synthetic biology, carboxysomes and other BMCs hold even greater potential when considered a source of building blocks for the development of nanoreactors or three-dimensional scaffolds to increase the efficiency of either native or heterologously expressed enzymes. The carboxysome serves as an ideal model system for testing approaches to engineering BMCs because their expression in cyanobacteria provides a sensitive screen for form (appearance of polyhedral bodies) and function (ability to grow on air). We recount recent progress in the re-engineering of the carboxysome shell and core to offer a conceptual framework for the development of BMC-based architectures for applications in plant synthetic biology. PMID:26991644

  18. Improved analysis of C4 and C3 photosynthesis via refined in vitro assays of their carbon fixation biochemistry

    Science.gov (United States)

    Sharwood, Robert E.; Sonawane, Balasaheb V.; Ghannoum, Oula; Whitney, Spencer M.

    2016-01-01

    Plants operating C3 and C4 photosynthetic pathways exhibit differences in leaf anatomy and photosynthetic carbon fixation biochemistry. Fully understanding this underpinning biochemical variation is requisite to identifying solutions for improving photosynthetic efficiency and growth. Here we refine assay methods for accurately measuring the carboxylase and decarboxylase activities in C3 and C4 plant soluble protein. We show that differences in plant extract preparation and assay conditions are required to measure NADP-malic enzyme and phosphoenolpyruvate carboxylase (pH 8, Mg2+, 22 °C) and phosphoenolpyruvate carboxykinase (pH 7, >2mM Mn2+, no Mg2+) maximal activities accurately. We validate how the omission of MgCl2 during leaf protein extraction, lengthy (>1min) centrifugation times, and the use of non-pure ribulose-1,5-bisphosphate (RuBP) significantly underestimate Rubisco activation status. We show how Rubisco activation status varies with leaf ontogeny and is generally lower in mature C4 monocot leaves (45–60% activation) relative to C3 monocots (55–90% activation). Consistent with their >3-fold lower Rubisco contents, full Rubisco activation in soluble protein from C4 leaves (<5min) was faster than in C3 plant samples (<10min), with addition of Rubisco activase not required for full activation. We conclude that Rubisco inactivation in illuminated leaves primarily stems from RuBP binding to non-carbamylated enzyme, a state readily reversible by dilution during cellular protein extraction. PMID:27122573

  19. Improved analysis of C4 and C3 photosynthesis via refined in vitro assays of their carbon fixation biochemistry.

    Science.gov (United States)

    Sharwood, Robert E; Sonawane, Balasaheb V; Ghannoum, Oula; Whitney, Spencer M

    2016-05-01

    Plants operating C3 and C4 photosynthetic pathways exhibit differences in leaf anatomy and photosynthetic carbon fixation biochemistry. Fully understanding this underpinning biochemical variation is requisite to identifying solutions for improving photosynthetic efficiency and growth. Here we refine assay methods for accurately measuring the carboxylase and decarboxylase activities in C3 and C4 plant soluble protein. We show that differences in plant extract preparation and assay conditions are required to measure NADP-malic enzyme and phosphoenolpyruvate carboxylase (pH 8, Mg(2+), 22 °C) and phosphoenolpyruvate carboxykinase (pH 7, >2mM Mn(2+), no Mg(2+)) maximal activities accurately. We validate how the omission of MgCl2 during leaf protein extraction, lengthy (>1min) centrifugation times, and the use of non-pure ribulose-1,5-bisphosphate (RuBP) significantly underestimate Rubisco activation status. We show how Rubisco activation status varies with leaf ontogeny and is generally lower in mature C4 monocot leaves (45-60% activation) relative to C3 monocots (55-90% activation). Consistent with their >3-fold lower Rubisco contents, full Rubisco activation in soluble protein from C4 leaves (plant samples (extraction. PMID:27122573

  20. Beech trees exposed to high CO{sub 2} and to simulated summer ozone levels: Effects on photosynthesis, chloroplast components and leaf enzyme activity

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, C. [Univ. of Innsbruck, Inst. of Botany, Innsbruck (Austria); Anegg, S. [GFS. National Research Centre for Environment and Health, Inst. of Biochemical Plant Pathology, Oberschleissheim (Germany); Gerant, D.; Dizengremel, P. [Univ. Henri Poincare Nancy 1, Lab. de Biologie Forestiere, Vandauvre les Nancy cedex (France); Alaoui-Sosse, B. [Lab. de Biologie et Ecophysiologie, Besancon cedex (France)

    2000-07-01

    Young trees of European beech (Fagus sylvatica L.) were exposed in a phytotron to different levels of ozone and CO{sub 2} under the climatic simulation of one vegetation period. High ozone levels were simulated similar to high ozone concentration in the field (up to 110 ppb), while CO{sub 2} was added as 300 ppm to the present level of ca 380 ppm. Our study describes different aspects of photosynthesis from the leaf level to the reactions of selected thylakoid components at different harvest times during growth of the beech trees under the different fumigation regimes. Ozone effects appeared in the first weeks of the treatment as a stimulation of chlorophyll fluorescence (F{sub v}/F{sub m}), in oxygen production and in ribulose-1,5-bisphosphate carboxylase/oxygenase activity, while the summer and early autumn harvests showed strong reductions in these parameters. Only phosphoenolpyruvate carboxylase (PEPcase) activity remained higher under high ozone. The effects of high CO{sub 2} appeared in general as a small stimulation in enzyme activity like PEPcase in spring. However, with increasing time of fumigation, reductions of all parameters were observed. Especially chlorophylls showed strong reductions under high CO{sub 2}. The combined treatment with high ozone plus high CO{sub 2} resulted mostly in an amelioration of the negative ozone effects, although control levels were not reached. (au)

  1. Redundancy of stomatal control for the circadian photosynthetic rhythm in Kalanchoë daigremontiana Hamet et Perrier.

    Science.gov (United States)

    Wyka, T P; Duarte, H M; Lüttge, U E

    2005-03-01

    In continuous light, the Crassulacean acid metabolism plant Kalanchoe daigremontiana Hamet et Perrier has a circadian rhythm of gas exchange with peaks occurring during the subjective night. The rhythm of gas exchange is coupled to a weak, reverse phased rhythm of quantum yield of photosystem II (Phi (PSII)). To test if the rhythm of Phi (PSII) persists in the absence of stomatal control, leaves were coated with a thin layer of translucent silicone grease which prevented CO2 and H2O exchange. In spite of this treatment, the rhythm of Phi (PSII) occurred with close to normal phase timing and with a much larger amplitude than in uncoated leaves. The mechanism underlying the Phi (PSII) rhythm in coated leaves can be explained by a circadian activity of phosphoenolpyruvate carboxylase (PEPC). At peaks of PEPC activity, the small amount of CO2 contained in the coated leaf could have become depleted, preventing the carboxylase activity of Rubisco and causing decreases in electron transport rates (observed as deep troughs of Phi (PSII) at 23-h in LL and at ca. 24-h intervals afterwards). Peaks of Phi (PSII) would be caused by a downregulation of PEPC leading to improved supply of CO2 to Rubisco. Substrate limitation of photochemistry at 23 h (trough of Phi (PSII)) was also suggested by the weak response of ETR in coated leaves to stepwise light enhancement. These results show that photosynthetic rhythmicity in K. daigremontiana is independent of stomatal regulation and may originate in the mesophyll. PMID:15822013

  2. Characterization of C₃--C₄ intermediate species in the genus Heliotropium L. (Boraginaceae): anatomy, ultrastructure and enzyme activity.

    Science.gov (United States)

    Muhaidat, Riyadh; Sage, Tammy L; Frohlich, Michael W; Dengler, Nancy G; Sage, Rowan F

    2011-10-01

    Photosynthetic pathway characteristics were studied in nine species of Heliotropium (sensu lato, including Euploca), using assessments of leaf anatomy and ultrastructure, activities of PEP carboxylase and C₄ acid decarboxylases, and immunolocalization of ribulose 1·5-bisphosphate carboxylase/oxygenase (Rubisco) and the P-subunit of glycine decarboxylase (GDC). Heliotropium europaeum, Heliotropium calcicola and Heliotropium tenellum are C₃ plants, while Heliotropium texanum and Heliotropium polyphyllum are C₄ species. Heliotropium procumbens and Heliotropium karwinskyi are functionally C₃, but exhibit 'proto-Kranz' anatomy where bundle sheath (BS) cells are enlarged and mitochondria primarily occur along the centripetal (inner) wall of the BS cells; GDC is present throughout the leaf. Heliotropium convolvulaceum and Heliotropium greggii are C₃--C₄ intermediates, with Kranz-like enlargement of the BS cells, localization of mitochondria along the inner BS wall and a loss of GDC in the mesophyll (M) tissue. These C₃--C₄ species of Heliotropium probably shuttle photorespiratory glycine from the M to the BS tissue for decarboxylation. Heliotropium represents an important new model for studying C₄ evolution. Where existing models such as Flaveria emphasize diversification of C₃--C₄ intermediates, Heliotropium has numerous C₃ species expressing proto-Kranz traits that could represent a critical initial phase in the evolutionary origin of C₄ photosynthesis. PMID:21631534

  3. Characterization of arsenite tolerant Halomonas sp. Alang-4, originated from heavy metal polluted shore of Gulf of Cambay.

    Science.gov (United States)

    Jain, Raina; Jha, Sanjay; Mahatma, Mahesh K; Jha, Anamika; Kumar, G Naresh

    2016-01-01

    Arsenite [As(III)]-oxidizing bacteria were isolated from heavy metal contaminated shore of Gulf of Cambay at Alang, India. The most efficient bacterial strain Alang-4 could tolerate up to 15 mM arsenite [As(III)] and 200 mM of arsenate [As(V)]. Its 16S rRNA gene sequence was 99% identical to the 16S rRNA genes of genus Halomonas (Accession no. HQ659187). Arsenite oxidase enzyme localized on membrane helped in conversion of As(III) to As(V). Arsenite transporter genes (arsB, acr3(1) and acr3(2)) assisted in extrusion of arsenite from Halomonas sp. Alang-4. Generation of ROS in response to arsenite stress was alleviated by higher activities of catalase, ascorbate peroxidase, superoxide dismutase and glutathione S-transferase enzymes. Down-regulation in the specific activities of nearly all dehydrogenases of carbon assimilatory pathway viz., glucose-6-phosphate, pyruvate, α-ketoglutarate, isocitrate and malate dehydrogenases, was observed in presence of As(III), whereas, the specific activities of phosphoenol pyruvate carboxylase, pyruvate carboxylase and isocitrate lyase enzymes were found to increase two times in As(III) treated cells. The results suggest that in addition to efficient ars operon, alternative pathways of carbon utilization exist in the marine bacterium Halomonas sp. Alang-4 to overcome the toxic effects of arsenite on its dehydrogenase enzymes. PMID:26865328

  4. Comparison of five endogenous reference genes for specific PCR detection and quantification of Brassica napus.

    Science.gov (United States)

    Wu, Gang; Zhang, Li; Wu, Yuhua; Cao, Yinglong; Lu, Changming

    2010-03-10

    Five previously reported Brassica napus endogenous reference genes, including acetyl-CoA carboxylase gene (BnACCg8), phosphoenolpyruvate carboxylase (PEP), oleoyl hydrolase gene (FatA), high-mobility-group protein I/Y gene (HMG-I/Y) and cruciferin A gene (CruA), were analyzed for their PCR specificity between B. napus and other species and the quantification stability among different B. napus cultivars. PCR and sequencing results indicated that none of these systems was species-specific as required by the genetically modified organism labeling policy. When these genes were employed in real-time PCR, BnACCg8 and HMG-I/Y systems showed relatively greater heterogeneity among 10 different cultivars. The sequencing results showed that the single nucleotide polymorphism in the primer binding sites was the potential source of the instability in the HMG-I/Y system. The bias of BnACCg8 was thought to be associated with the inconsistent copy number of this gene. PMID:20143854

  5. The LysR-type transcription factor PacR is a global regulator of photosynthetic carbon assimilation in Anabaena.

    Science.gov (United States)

    Picossi, Silvia; Flores, Enrique; Herrero, Antonia

    2015-09-01

    Cyanobacteria perform water-splitting photosynthesis and are important primary producers impacting the carbon and nitrogen cycles at global scale. They fix CO2 through ribulose-bisphosphate carboxylase/oxygenase (RuBisCo) and have evolved a distinct CO2 concentrating mechanism (CCM) that builds high CO2 concentrations in the vicinity of RuBisCo favouring its carboxylase activity. Filamentous cyanobacteria such as Anabaena fix CO2 in photosynthetic vegetative cells, which donate photosynthate to heterocysts that rely on a heterotrophic metabolism to fix N2 . CCM elements are induced in response to inorganic carbon limitation, a cue that exposes the photosynthetic apparatus to photodamage by over-reduction. An Anabaena mutant lacking the LysR-type transcription factor All3953 grew poorly and dies under high light. The rbcL operon encoding RuBisCo was induced upon carbon limitation in the wild type but not in the mutant. ChIP-Seq analysis was used to globally identify All3953 targets under carbon limitation. Targets include, besides rbcL, genes encoding CCM elements, photorespiratory pathway- photosystem- and electron transport-related components, and factors, including flavodiiron proteins, with a demonstrated or putative function in photoprotection. Quantitative reverse transcription polymerase chain reaction analysis of selected All3953 targets showed regulation in the wild type but not in the mutant. All3953 (PacR) is a global regulator of carbon assimilation in an oxygenic photoautotroph. PMID:25684321

  6. Overexpression of malate dehydrogenase in transgenic alfalfa enhances organic acid synthesis and confers tolerance to aluminum.

    Science.gov (United States)

    Tesfaye, M; Temple, S J; Allan, D L; Vance, C P; Samac, D A

    2001-12-01

    Al toxicity is a severe impediment to production of many crops in acid soil. Toxicity can be reduced through lime application to raise soil pH, however this amendment does not remedy subsoil acidity, and liming may not always be practical or cost-effective. Addition of organic acids to plant nutrient solutions alleviates phytotoxic Al effects, presumably by chelating Al and rendering it less toxic. In an effort to increase organic acid secretion and thereby enhance Al tolerance in alfalfa (Medicago sativa), we produced transgenic plants using nodule-enhanced forms of malate dehydrogenase and phosphoenolpyruvate carboxylase cDNAs under the control of the constitutive cauliflower mosaic virus 35S promoter. We report that a 1.6-fold increase in malate dehydrogenase enzyme specific activity in root tips of selected transgenic alfalfa led to a 4.2-fold increase in root concentration as well as a 7.1-fold increase in root exudation of citrate, oxalate, malate, succinate, and acetate compared with untransformed control alfalfa plants. Overexpression of phosphoenolpyruvate carboxylase enzyme specific activity in transgenic alfalfa did not result in increased root exudation of organic acids. The degree of Al tolerance by transformed plants in hydroponic solutions and in naturally acid soil corresponded with their patterns of organic acid exudation and supports the concept that enhancing organic acid synthesis in plants may be an effective strategy to cope with soil acidity and Al toxicity. PMID:11743127

  7. Metabolic networks to generate pyruvate, PEP and ATP from glycerol in Pseudomonas fluorescens.

    Science.gov (United States)

    Alhasawi, Azhar; Thomas, Sean C; Appanna, Vasu D

    2016-04-01

    Glycerol is a major by-product of the biodiesel industry. In this study we report on the metabolic networks involved in its transformation into pyruvate, phosphoenolpyruvate (PEP) and ATP. When the nutritionally-versatile Pseudomonas fluorescens was exposed to hydrogen peroxide (H2O2) in a mineral medium with glycerol as the sole carbon source, the microbe reconfigured its metabolism to generate adenosine triphosphate (ATP) primarily via substrate-level phosphorylation (SLP). This alternative ATP-producing stratagem resulted in the synthesis of copious amounts of PEP and pyruvate. The production of these metabolites was mediated via the enhanced activities of such enzymes as pyruvate carboxylase (PC) and phosphoenolpyruvate carboxylase (PEPC). The high energy PEP was subsequently converted into ATP with the aid of pyruvate phosphate dikinase (PPDK), phosphoenolpyruvate synthase (PEPS) and pyruvate kinase (PK) with the concomitant formation of pyruvate. The participation of the phospho-transfer enzymes like adenylate kinase (AK) and acetate kinase (ACK) ensured the efficiency of this O2-independent energy-generating machinery. The increased activity of glycerol dehydrogenase (GDH) in the stressed bacteria provided the necessary precursors to fuel this process. This H2O2-induced anaerobic life-style fortuitously evokes metabolic networks to an effective pathway that can be harnessed into the synthesis of ATP, PEP and pyruvate. The bioconversion of glycerol to pyruvate will offer interesting economic benefit. PMID:26920481

  8. Geniposide regulates glucose-stimulated insulin secretion possibly through controlling glucose metabolism in INS-1 cells.

    Directory of Open Access Journals (Sweden)

    Jianhui Liu

    Full Text Available Glucose-stimulated insulin secretion (GSIS is essential to the control of metabolic fuel homeostasis. The impairment of GSIS is a key element of β-cell failure and one of causes of type 2 diabetes mellitus (T2DM. Although the KATP channel-dependent mechanism of GSIS has been broadly accepted for several decades, it does not fully describe the effects of glucose on insulin secretion. Emerging evidence has suggested that other mechanisms are involved. The present study demonstrated that geniposide enhanced GSIS in response to the stimulation of low or moderately high concentrations of glucose, and promoted glucose uptake and intracellular ATP levels in INS-1 cells. However, in the presence of a high concentration of glucose, geniposide exerted a contrary role on both GSIS and glucose uptake and metabolism. Furthermore, geniposide improved the impairment of GSIS in INS-1 cells challenged with a high concentration of glucose. Further experiments showed that geniposide modulated pyruvate carboxylase expression and the production of intermediates of glucose metabolism. The data collectively suggest that geniposide has potential to prevent or improve the impairment of insulin secretion in β-cells challenged with high concentrations of glucose, likely through pyruvate carboxylase mediated glucose metabolism in β-cells.

  9. Preparation of intact chloroplasts by chemically induced lysis of the green alga Dunaliella marina.

    Science.gov (United States)

    Kombrink, E; Wöber, G

    1980-07-01

    A method for the isolation in high yield of intact chloroplasts from the unicellular green alga Dunaliella marina (Volvocales) is described. This procedure uses chemically induced lysis of cells with the polycationic macromolecules, DEAE-dextran (M=500,000) or poly-D,L-lysine (M=30,000-70,000). Reaction conditions were optimized with respect to obtaining a high yield of intact chloroplasts, after isopycnic centrifugation in a linear sucrose density gradient, by varying the concentration of polycation and the temperature and pH of incubation. Broken chloroplasts devoid of the stromal marker enzymes fructosebisphosphate phosphatase and ribulosebisphosphate carboxylase, but containing mitochondrial (fumarase) and microbody (catalase) contamination, were banded at a bouyant density of 1.18 g cm(-3). Intact chloroplasts, as indicated by their retention of alkaline fructosebisphosphate phosphatase and ribulosebisphosphate carboxylase, were found in 30% yield (chlorophyll in intact cells, 100%) at an equilibrium density of 1.24 g cm(-3). Contamination by cytoplasmic material (pyruvate kinase), mitochondria, and microbodies was less than 8% each. PMID:24306242

  10. Effect of prolactin on enzymes of lipid biosynthesis in mammary gland explants

    International Nuclear Information System (INIS)

    Prolactin (PRL) stimulates an increased rate of incorporation of [14C]acetate and [3H]glucose into lipids in cultured mammary gland explants from 10-to 14-day-pregnant mice. This response is biphasic with an early increase occurring from 6 through 12 h, and an additional increase from 16 to 24 h. Enzymes likely to be rate limiting to this process include acetyl CoA carboxylase, fatty acid synthetase, acetyl CoA synthetase, and/or pyruvate dehydrogenase. Of these enzymes only pyruvate dehydrogenase activity was elevated at 6 h, suggesting that this enzymatic activity is important in stimulating early increases in lipogenesis after PRL treatment. In addition, the PRL stimulation of pyruvate dehydrogenase may also indirectly stimulate acetyl CoA carboxylase through the generation of citrate; this may explain the early (6-12 h) effect of PRL on [14C]acetate incorporation. After 16 h of PRL treatment, the activities of all the lipogenic enzymes were enhanced. The second phase of PRLs stimulation of lipogenesis thus likely involves the enhanced activities of more than one of the lipogenic enzymes

  11. Mechanism of coumarin action: sensitivity of vitamin K metabolizing enzymes of normal and warfarin-resistant rat liver.

    Science.gov (United States)

    Hildebrandt, E F; Suttie, J W

    1982-05-11

    The in vitro effects of two coumarin anticoagulants, warfarin and difenacoum, on rat liver microsomal vitamin K dependent carboxylase, vitamin K epoxidase, vitamin K epoxide reductase, and cytosolic vitamin K reductase (DT-diaphorase) from the livers of normal and a warfarin-resistant strain of rats have been determined. Millimolar concentrations of both coumarins are required to inhibit the carboxylase and epoxidase activities in both strains of rats. Sensitivity of DT-diaphorase to coumarin inhibition differs when a soluble or liposomal-associated substrate is used, but the diaphorases isolated from both strains of rats have comparable sensitivity. The anticoagulant difenacoum is an effective rodenticide in the warfarin-resistant strain of rats, and the only enzyme studied from warfarin-resistant rat liver that demonstrated a significant differential inhibition by the two coumarins used was the vitamin K epoxide reductase. This enzyme also showed the greatest sensitivity to coumarin inhibition among the enzymes studied. These results support the hypothesis that the physiologically important site of action of coumarin anticoagulants is the vitamin K epoxide reductase. PMID:6807339

  12. ROS-mediated glucose metabolic reprogram induces insulin resistance in type 2 diabetes.

    Science.gov (United States)

    Dong, Kelei; Ni, Hua; Wu, Meiling; Tang, Ziqing; Halim, Michael; Shi, Dongyun

    2016-08-01

    Oxidative stress is known to contribute to insulin resistance in diabetes, however the mechanism is not clear. Here we show that reactive oxygen species (ROS) could reprogram the glucose metabolism through upregulating the pentose pathway so as to induce insulin resistance in type 2 diabetes (T2DM). By using streptozotocin-high fat diet (STZ-HFD) induced T2DM in rats, we show that diabetic rats exhibited high level of oxidative stress accompanied with insulin resistance. Hypoxia inducible factor (HIF-1α) protein expression as well as its downstream target glucokinase (GK), were upregulated; The glycogen synthesis increased accordingly; However the glycolysis was inhibited as indicated by decreased phosphofructokinase-1 (PFK-1), pyruvate kinase (PK), phospho-PFK-2/PFK-2 (p-PFK-2/PFK-2) ratio, lactate dehydrogenase (LDH) and pyruvate dehydrogenase kinase (PDK); Pyruvate dehydrogenase (PDH) which promotes pyruvate to generate acetyl-CoA declined as well. While phospho-acetyl-CoA carboxylase/acetyl-CoA carboxylase (p-ACC/ACC) ratio increased, meaning that lipid beta-oxidation increased. The pentose pathway was activated as indicated by increased G6PD activity and NADPH level. Our results suggest that diabetic rats countervail ROS stress through increasing pentose pathway, and reprogram the energy metabolic pathway from glycolysis into lipid oxidation in order to compensate the ATP requirement of the body, which causes insulin resistance. PMID:27207834

  13. Influence of the nitrate concentration and source in the incorporation of 14CO2 by the RuBP-carboxilase from wheat (triticum aestivum) and maize (zea mays)

    International Nuclear Information System (INIS)

    The effect of the concentration and source of nitrogen in the culture media has been studied regarding its influence in the activity of the RuBP-carboxylase from wheat and maize during the first month of development. Wheat and maize has been chosen as plants representatives of two different types of CO2 assimilation: C3 and C4 respectively. Plants have been brown in hydroponic media and under temperature, humidity and nutrient salts control. A negative effect of NH4+ has been observed in the enzymatic activity of wheat seedlings, being this effect more remarkable as NH4+ concentration increases and as long the time of treatment. In our experimental conditions the most favorable source of nitrogen has been NO3NH4. The specific activity of the enzyme from wheat is about four times higher than in maize, even it decreases with time. This decreaseing has not been observed in maize, with the exception of total absence of nitrogen in the media. We have not seen significant differences between the two photoperiods which have been tested. Also no differences have been found in the enzyme activities at the different NO3NH4 concentrations assayed, and it seems that RuBP-carboxylase metabolism is only affected in the case of absolute stress. (author)

  14. Specific radioactivity of glycolate and photorespiration during 14CO2 assimilation at four different CO2 concentrations by sunflower and bean leaves

    International Nuclear Information System (INIS)

    Using an open gas-exchange system, the rates of apparent CO2 uptake (APS), true CO2 uptake (TIPS), CO2 evolution in light (PR), and the relative specific radioactivity of photorespiration (RSA) by sunflower and bean leaves were measured at four different CO2 concentrations. At the end of the 14CO2 assimilation period the leaves were killed and extract for the analysis of glycolic acid. The rate of PR was CO2 independent at low and normal CO2 concentrations but inreased at CO2 concentrations above normal. The ratio of PR/TPS which declined with an increase in CO2 was compatible with the ratio of vo/2vo of the RuBP-Carboxylase/Oxygenase reaction. At low and normal concentrations of CO2 the concentration as well as the specific radioactivity of glycolic acid increased with an increase in CO2 and the relative specific activity (RSA) of glycolic acid resembled the RSA of photorespiration. It was concluded that these results support the concept of RuBP-carboxylase/oxygenase regulating the fluxes of carbon via the photosynthetic carbon reduction and the glycolate pathway. (orig.)

  15. 14CO2 pulse-12CO2 chase analyses of C4-acid metabolism in C3-C4 intermediate species of Flaveria at the CO2 compensation concentration (r)

    International Nuclear Information System (INIS)

    Photosynthetic C4-acid metabolism in leaves of C3-C4 intermediate Flaveria species was examined by 14CO2 pulse-12CO2 chase experiments conducted at external CO2-levels approximating air and γ. Analysis of the percent distribution of 14C after a 10-s pulse showed an enhanced labeling of malate and aspartate at γ in the C3-C4 species. This stimulation of 14CO2 fixation by PEP carboxylase ranged from 1.7-(F. floridana) to 3.6-fold (F. anomala). A 12CO2-chase at γ revealed a significant turnover of C4 acids for only F. floridana. C4-acid labeling in C3 and C4 Flaveria species was relatively unresponsive to changes in pCO2. These data imply that the C3-C4 intermediate Flaveria species with less advanced C4 attributes have a greater capacity for increased CO2 fixation via PEP carboxylase at γ versus air. Thus, labeling of C3-C4 leaves at Σ may be an effective tool for assessing the degree of true C4-photosynthesis as well as the potential mechanism involved in reducing photorespiration

  16. Reduced apparent photorespiration by the C3-C4 intermediate species, Moricandia arvensis and Panicum milioides

    International Nuclear Information System (INIS)

    The CO2/O2 specificity factor of sucrose gradient purified ribulose 1,5-bisphosphate carboxylase/oxygenase from the C3-C4 intermediate plants Moricandia arvensis and Panicum milioides was similar to the respective values of the enzyme from the closely related C3 species, Moricandia foetida and Panicum laxum. Thus, the kinetic properties of this bifunctional enzyme do not explain the reduced rates of photorespiration exhibited by either of these intermediate species. Dark/light ratios for aminoacetonitrile-sensitive 14CO2 evolution during decarboxylation of exogenous [1-14C] glycine by leaf discs had values of 9.0 with M. arvensis and 11.8 with P. milioides. Similar results were obtained using [1-14C] glycolate as the exogenous photorespiratory substrate, with dark/light 14CO2 evolution ratios for the C3-C4 and C3 leaf discs averaging 6.6 and 2.0, respectively. The data suggest that P. milioides and M. arvensis are capable of a more efficient internal recycling of photorespiratory CO2 via ribulose bisphosphate carboxylase/oxygenase than closely related C3 plants, and that this may partially account for the reduced rates of apparent photorespiration by these intermediate species

  17. Differential Localization of Antioxidants in Maize Leaves.

    Science.gov (United States)

    Doulis, A. G.; Debian, N.; Kingston-Smith, A. H.; Foyer, C. H.

    1997-07-01

    The aim of this work was to determine the compartmentation of antioxidants between the bundle-sheath and mesophyll cells of maize (Zea mays L.) leaves. Rapid fractionation of the mesophyll compartment was used to minimize modifications in the antioxidant status and composition due to extraction procedures. The purity of the mesophyll isolates was assessed via the distribution of enzyme and metabolite markers. Ribulose-1,5 bisphosphate and ribulose-1,5-bisphosphate carboxylase/oxygenase were used as bundle-sheath markers and phosphoenolpyruvate carboxylase was used as the mesophyll marker enzyme. Glutathione reductase and dehydroascorbate reductase were almost exclusively localized in the mesophyll tissue, whereas ascorbate, ascorbate peroxidase, and superoxide dismutase were largely absent from the mesophyll fraction. Catalase, reduced glutathione, and monodehydroascorbate reductase were found to be approximately equally distributed between the two cell types. It is interesting that, whereas H2O2 levels were relatively high in maize leaves, this oxidant was largely restricted to the mesophyll compartment. We conclude that the antioxidants in maize leaves are partitioned between the two cell types according to the availability of reducing power and NADPH and that oxidized glutathione and dehydroascorbate produced in the bundle-sheat tissues have to be transported to the mesophyll for re-reduction to their reduced forms. PMID:12223757

  18. New Insights into the Nitrogen Form Effect on Photosynthesis and Photorespiration

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Under high light conditions, ammonium nutrition has a negative effect on plant growth. This suggests that the adverse effects of ammonium nutrition on plant growth may be related to carbon gain, photosynthesis, and photorespiration.However, there is no consistent evidence of a specific mechanism that could explain the plant growth reduction under ammonium supply. It is generally accepted that during the light reaction, a surplus of nicotinamide adenine dinucleotide hydrogen phosphate (NADPH) is produced, which is not completely used during the assimilation of CO2. Nitrate reduction in the leaf represents an additional sink for NADPH that is not available to ammonium-grown plants. Nitrate and ammonium nutrition may use different pathways for NADPH consumption, which leads to differences in photosynthesis and photorespiration. The morphological (i.e., cell size, mesophyll thickness, and chloroplast volume) and enzymic (i.e.,ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPCase), and glutamine synthetase/glutamate synthetase (GS/GOGAT)) differences that develop when plants are treated with either nitrate or ammonium nitrogen forms are related to photosynthesis and photorespiration. The differences in photorespiration rate for plants treated with nitrate or ammonium are related to the conversion of citrate to 2-oxoglutarate (2-OG) and photorespiratory CO2 refixation.

  19. Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Eiteman

    2005-11-01

    This report describes results toward developing a process to sequester CO{sub 2} centered on the enzyme pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The first phase of this research has focused on strain development and on process development. Progress in strain development has been made in three areas. The gene encoding for alcohol dehydrogenase has been ''knocked out'' of the bacteria, and thereby eliminating the synthesis of the by-product ethanol. The gene for glucokinase has been overexpressed in the production strain with the goal of faster utilization of glucose (and hence CO{sub 2}). Efforts have continued toward integrating pyruvate carboxylase gene (pyc) onto the E. coli chromosome. Progress in process development has come in conducting several dozen fermentation experiments to find a defined medium that would be successful for the growth of the bacteria, while permitting a high rate of CO{sub 2} utilization in a subsequent prolonged production phase. Using this defined medium, the strains that continue to be constructed are being compared for CO{sub 2} utilization, so that we may understand the factors that govern the biological sequestration process.

  20. Tobacco guard cells fix CO2 by both Rubisco and PEPcase while sucrose acts as a substrate during light-induced stomatal opening.

    Science.gov (United States)

    Daloso, Danilo M; Antunes, Werner C; Pinheiro, Daniela P; Waquim, Jardel P; Araújo, Wagner L; Loureiro, Marcelo E; Fernie, Alisdair R; Williams, Thomas C R

    2015-11-01

    Transcriptomic and proteomic studies have improved our knowledge of guard cell function; however, metabolic changes in guard cells remain relatively poorly understood. Here we analysed metabolic changes in guard cell-enriched epidermal fragments from tobacco during light-induced stomatal opening. Increases in sucrose, glucose and fructose were observed during light-induced stomatal opening in the presence of sucrose in the medium while no changes in starch were observed, suggesting that the elevated fructose and glucose levels were a consequence of sucrose rather than starch breakdown. Conversely, reduction in sucrose was observed during light- plus potassium-induced stomatal opening. Concomitant with the decrease in sucrose, we observed an increase in the level as well as in the (13) C enrichment in metabolites of, or associated with, the tricarboxylic acid cycle following incubation of the guard cell-enriched preparations in (13) C-labelled bicarbonate. Collectively, the results obtained support the hypothesis that sucrose is catabolized within guard cells in order to provide carbon skeletons for organic acid production. Furthermore, they provide a qualitative demonstration that CO2 fixation occurs both via ribulose-1,5-biphosphate carboxylase/oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPcase). The combined data are discussed with respect to current models of guard cell metabolism and function. PMID:25871738

  1. Influences of dietary biotin and avidin on growth, survival, deficiency syndrome and hepatic gene expression of juvenile Nile tilapia Oreochromis niloticus.

    Science.gov (United States)

    Sarker, Pallab Kumer; Yossa, Rodrigue; Karanth, Santhosh; Ekker, Marc; Vandenberg, Grant W

    2012-08-01

    This study was undertaken to assess the interactive effects of dietary biotin and avidin on growth, feed conversion, survival and deficiency syndrome of tilapia and to determine the influence of dietary biotin deficiency on the expression of key genes related to biotin metabolism in tilapia. Six iso-nitrogenous and iso-energetic diets based on a common purified basal diet (vitamin-free casein as the protein source) were prepared for this study. The six dietary groups were 0 g avidin with 0 mg biotin (A0B0), 0 g avidin with 0.06 mg biotin/kg diet (A0B1), four avidin-supplemented diets incorporating at a incremental concentrations 0.25, 0.5, 1.0 and 2.0 g/kg diet with 0.06 mg biotin/kg diet (A15B1, A30B1, A60B1 and A120B1). Fish were hand-fed three times a day to apparent satiation for 12 weeks. Each diet was fed to three replicate groups of fish. Fish were kept in glass aquaria in a recirculating aquaculture system under standardized environmental conditions. Growth was significantly higher in fish that received the biotin-supplemented diet (A0B1), compared to diets lacking biotin or supplemented with avidin. Tilapia fed higher concentration of avidin-supplemented diets (A60B1 and A120B1) showed significant growth depression and displayed severe deficiency syndromes such as lethargy, anorexia, circular swimming and convulsions, which ultimately lead to death. There was a strong proportional linear relationship between the avidin content of the diet and feed conversion ratio, FCR (y = 0.43x + 0.135; r = 0.960; P < 0.001) and strong inverse relationship with protein efficiency ratio, PER (y = -0.309x + 2.195; r = 0.961; P < 0.0001). Elevated levels of biotinidase, pyruvate carboxylase, propionyl-CoA carboxylase-A and propionyl-CoA carboxylase-B transcripts were noted in fish fed all graded level of avidin-supplemented diets. A broken-line analysis indicated that feeding tilapia a diet with 44.5 times more avidin than the dietary biotin

  2. Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Eiteman

    2006-07-31

    This report describes results toward developing a process to sequester CO{sub 2} centered on the enzyme pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The phases of research have included strain development and process development. Though we continue to work on one important component of strain development, the research has principally focused on process development. In the previous year we constructed several strains which would serve as templates for the CO{sub 2} sequestration, including the knock-out of genes involved in the formation of undesirable byproducts. This project period the focus has been on the integration of the pyruvate carboxylase gene (pyc) onto the E. coli chromosome. This has proven to be a difficult task because of relatively low expression of the gene and resulting low enzyme activity when only one copy of the gene is present on the chromosome. Several molecular biology techniques have been applied, with some success, to improve the level of protein activity as described herein. Progress in process development has come as a result of conducting numerous fermentation experiments to select optimal conditions for CO{sub 2} sequestration. This process-related research has progressed in four areas. First, we have clarified the range of pH which results in the optimal rate of sequestration. Second, we have determined how the counterion used to control the pH affects the sequestration rate. Third, we have determined how CO{sub 2} gas phase composition impacts sequestration rate. Finally, we have made progress in determining the affect of several potential gaseous impurities on CO{sub 2} sequestration; in particular we have completed a study using NO{sub 2}. Although the results provide significant guidance as to process conditions for CO{sub 2} sequestration and succinate production, in some cases we do not yet understand

  3. Cutaneous findings of nutritional deficiencies in children.

    Science.gov (United States)

    Goskowicz, M; Eichenfield, L F

    1993-08-01

    Nutritional deficiencies may be associated with a variety of cutaneous findings in children. This review emphasizes new developments relating to cutaneous findings of nutritional deficiencies. Zinc deficiency, acrodermatitis enteropathica, and acrodermatitis enteropathica-like eruptions are seen with a variety of conditions including cystic fibrosis, anorexia nervosa, and breastfeeding. Similar cutaneous findings not related to zinc deficiency may also occur with such metabolic disorders as methylmalonic aciduria, multiple carboxylase deficiency, essential fatty acid deficiency and other amino acid deficiencies. Vitamin K deficiency is associated with hemorrhagic disease of the newborn and coagulopathy. Vitamin A deficiency presents with a variety of systemic findings and distinctive dermatologic findings. Acute vitamin A deficiency may be seen in children infected with measles and is associated with more severe disease. The systemic and cutaneous findings of vitamin C deficiency, scurvy, are discussed. PMID:8374671

  4. Effects and Mechanisms of P and K Nutrients on Yield and Protein Content of Fodder Rice

    Institute of Scientific and Technical Information of China (English)

    TANG Xiang-ru; YU Tie-qiao

    2002-01-01

    Effects and mechanisms of P and K nutrients on yield and protein content of Weiyou 56, a fodder hybrid rice combination, were studied through pot experiment and biochemical analysis. The results showed that the increase of P and K nutrients enhanced the activities of PEP carboxylase (PEPC), glutamine synthase (GS) and sucrose phosphate synthase (SPS) in leaves, sucrose synthase (SS), ADP glucose pyrophosphorylase (ADPGP) and GS in grains, and the chlorophyll content in leaves, soluble sugar and starch content in grains,protein N and total N content in leaves and grains. Howerer, they decreased soluble sugar content in leaves and led to an increase of protein content in brown rice, biomass, grain yield and harvest index. Excessive P nutrients slightly reduced SPS and ADPG activity in leaves and grains respectively.

  5. AcEST: DK956134 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 3 ... 30 8.4 sp|Q8WJ32|MATK_BACMR Maturase K OS=Backhousia myrtifolia GN=matK... 25 9.4 >sp|Q9SV21|COPB1_ARA... sp|O62992|MATK_LEDPA Maturase K OS=Ledum palustre GN=matK PE=3 SV=1 30 6.4 sp|Q5GM68|CAPP2_ARATH Phosphoeno...lpyruvate carboxylase 2 OS=Arabi... 30 6.4 sp|Q8UI71|ARGD_AGRT5 Acetylornithine aminotransferase OS=Agrobac....|P43248|MSH2_DROME DNA mismatch repair protein spellchecker 1 ... 31 4.9 sp|O62991|MATK_RHOTS Maturase K OS=Rho...r_hit_id A5AHP0 Definition tr|A5AHP0|A5AHP0_VITVI Putative uncharacterized protein (Chromosome chr4 scaffold_6, whole genome sho

  6. Fat metabolism is regulated by altered gene expression oflipogenic enzymes and regulatory factors in liver and adiposetissue but not in semimembranosus muscle of pigs during thefattening period

    DEFF Research Database (Denmark)

    Duran-Montge, P; Theil, Peter Kappel; Lauridsen, Charlotte;

    2009-01-01

    It has been shown previously that lipid metabolism is regulated by fatty acids (FA) and that thyroid hormones are important regulators of energy metabolism. The effects of weight, dietary fat level and dietary FA profile on thyroid hormone levels and expression of lipogenic genes and tissue FA...... supplemented with approximately 10% fat of different origin and slaughtered at 100 kg BW. The supplemental fats were tallow, high-oleic sunflower oil, sunflower oil (SFO), linseed oil, fat blend (55% tallow, 35% sunflower oil, 10% linseed oil) and fish oil blend (40% fish oil, 60% linseed oil). In general, the...... hormones and genes encoding enzymes of fat synthesis in adipose tissue (acetyl CoA carboxylase (ACACA), fatty acid synthase and stearoyl CoA desaturase (SCD)) and the large differences in expression of lipogenic genes at different weights (60 and 100 kg BW), suggest a role for thyroid hormones and for T3...

  7. MODIFICATION DE L’AMIDON ET L’ETUDE DE SES PROPRIETES EN SOLUTION

    OpenAIRE

    MAHAMMEDI, Fatiha

    2010-01-01

    Les objectifs de la présente étude, sont d’augmenter le caractère hydrophile de l’amidon, en introduisant des groupes carboxylases supportés par la molécule d’acide citrique préalablement greffée. Les polyelectrolytes obtenus pourraient servir, entre autres, à éliminer l’excès des sels présents dans les eaux salées et dans les sols. Les citrates de l’amidon sont obtenus à partir de l’amidon via une réaction d’estérification en présence d’acide citrique. Donc, on introduit une appréciabl...

  8. Piperlongumine as a potential activator of AMP-activated protein kinase in HepG2 cells.

    Science.gov (United States)

    Ryu, Jahee; Kim, Myoung-Jin; Kim, Tae-Oh; Huh, Tae-Lin; Lee, Sung-Eun

    2014-01-01

    AMP-activated protein kinase (AMPK) is a key regulator of fatty acid biosynthesis and fatty acid oxidation throughout the body. Piperlongumine (PL) isolated from Piper longum (L.) was shown to potently upregulate activation of AMPK via phosphorylation and inactivation of acetyl-CoA carboxylases in cultured HepG2 cells, presumably enhancing the transfer of fatty acids into mitochondrial cells by inhibiting malonyl-CoA production. PL showed cytotoxicity on HepG2 cell growth at the concentration of 5 μM of PL, while more than 80% of HepG2 cells were survived at the concentration of 2 μM of PL. Overall, the results of this study indicate that PL activates AMPK phosphorylation and possesses cytotoxicity in HepG2 cells. PMID:24853732

  9. AcEST: DK963134 [AcEST

    Lifescience Database Archive (English)

    Full Text Available BlastX Result : TrEMBL tr_hit_id A4EAA5 Definition tr|A4EAA5|A4EAA5_9ACTN Putative uncharacterized protein OS=Collinsella aero..................done Score E Sequences producing significant alignments: (bits) Value tr|A4EAA5|A4EAA5_9ACTN Putative uncharacter... OS=Vitis... 34 9.0 >tr|A4EAA5|A4EAA5_9ACTN Putative uncharacterized protein OS=Collinsella aerofaci...s Searching..................................................done Score E Sequences producing significan...tease vpr OS=Bacillu... 30 8.5 >sp|Q8TMG9|CAPPA_METAC Phosphoenolpyruvate carboxylase OS=Methanosarcina ace

  10. Study of the properties of ribulose 1,5 biphosphate carboxilase oxygenase from maize (zea mays) and wheat (triticum aestivum) by incorporation of 14CO2

    International Nuclear Information System (INIS)

    After a bibliografic review of the properties of RuBP-carboxylase/oxygenase, a methodology is described which allows the treatment of a large number for the counting assay pf the enzyme activity. 14CO3HNa is used as a marker for the counting of the incorporated radioactivity as acid insoluble material. 14CO2 from de labelled sodium carbonate is the species used by the enzyme both as an activator as well as a substrate. The following experiments are described and its results given: Determination of the optimal conditions for the activation of the enzyme; study of the kinetics of the catalytic action; effect of the Mg2+ concentration and determination of the Kmsub((s)) from CO2 and ribulose 1,5-biphosphate; also determination of the optimun pH at different concentrations of CO2 and Mg2+. (author)

  11. AMPK-mediated AS160 phosphorylation in skeletal muscle is dependent on AMPK catalytic and regulatory subunits

    DEFF Research Database (Denmark)

    Treebak, Jonas Thue; Glund, Stephan; Deshmukh, Atul;

    2006-01-01

    signaling to glucose uptake. We show that AICAR increases AMPK, acetyl-CoA carboxylase, and AS160 phosphorylation by insulin-independent mechanisms in isolated skeletal muscle. Recombinant AMPK heterotrimeric complexes (a1ß1¿1 and a2ß2¿1) phosphorylate AS160 in a cell-free assay. In mice deficient in AMPK...... signaling (a2 AMPK knockout [KO], a2 AMPK kinase dead [KD], and ¿3 AMPK KO), AICAR effects on AS160 phosphorylation were severely blunted, highlighting that complexes containing a2 and ¿3 are necessary for AICAR-stimulated AS160 phosphorylation in intact skeletal muscle. Contraction-mediated AS160......AMP-activated protein kinase (AMPK) is a heterotrimeric protein that regulates glucose transport mediated by cellular stress or pharmacological agonists such as 5-aminoimidazole-4-carboxamide 1 ß-D-ribonucleoside (AICAR). AS160, a Rab GTPase-activating protein, provides a mechanism linking AMPK...

  12. [Effect of univalent cations on synthesis of surfactants by Acinetobacter calcoaceticus IMV B-7241].

    Science.gov (United States)

    Pirog, T P; Shevchuk, T A; Antoniuk, S I; Kravchenko, E Iu; Iutinskaia, G A

    2013-01-01

    The effect of univalent cations on activity of key enzymes of C2-metabolism has been investigated in the producer of biosurfactants, Acinetibacter calcoaceticus IMV B-7241 grown on ethanol. It was established that potassium cations are inhibitors of pyroquinolinequinone-dependent alcohol- and acetaldehyde dehydrogenases, the enzymes of biosynthesis of surface-active aminolipids (NADP-dependent glutamate dehydrogenase) and glycolipids (phosphoenopyruvate (PhEP)-carboxikinase), while ammonium cations are activators of these enzymes and PhEP-carboxylase. A decrease of potassium cations concentration in the cultivation medium to 1 mM and increase of the content of amine nitrogen to 10 mM as a result of potassium nitrate substitution by equimolar, as to nitrogen, urea concentration were accompanied by the increase of activity of enzymes of ethanol metabolism and SAS biosynthesis, as well as by the 2-fold increase of conditional concentration of the biosurfactants. PMID:23720959

  13. Metabolic engineering of cottonseed oil biosynthesis pathway via RNA interference.

    Science.gov (United States)

    Xu, Zhongping; Li, Jingwen; Guo, Xiaoping; Jin, Shuangxia; Zhang, Xianlong

    2016-01-01

    Cottonseed oil is recognized as an important oil in food industry for its unique characters: low flavor reversion and the high level of antioxidants (VitaminE) as well as unsaturated fatty acid. However, the cottonseed oil content of cultivated cotton (Gossypium hirsutum) is only around 20%. In this study, we modified the accumulation of oils by the down-regulation of phosphoenolpyruvate carboxylase 1 (GhPEPC1) via RNA interference in transgenic cotton plants. The qRT-PCR and enzyme activity assay revealed that the transcription and expression of GhPEPC1 was dramatically down-regulated in transgenic lines. Consequently, the cottonseed oil content in several transgenic lines showed a significant (P information for cottonseed oil biosynthesis pathway and shows the potential of creating high cottonseed oil germplasm by RNAi strategy for cotton breeding. PMID:27620452

  14. Organic acid-tolerant microorganisms and uses thereof for producing organic acids

    Science.gov (United States)

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-05-06

    Organic acid-tolerant microorganisms and methods of using same. The organic acid-tolerant microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid (3HP), acrylic acid, and propionic acid. Further modifications to the microorganisms such as increasing expression of malonyl-CoA reductase and/or acetyl-CoA carboxylase provide or increase the ability of the microorganisms to produce 3HP. Methods of generating an organic acid with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers include replacing acsA or homologs thereof in cells with genes of interest and selecting for the cells comprising the genes of interest with amounts of organic acids effective to inhibit growth of cells harboring acsA or the homologs.

  15. Chloroplast transformation for engineering of photosynthesis.

    Science.gov (United States)

    Hanson, Maureen R; Gray, Benjamin N; Ahner, Beth A

    2013-01-01

    Many efforts are underway to engineer improvements in photosynthesis to meet the challenges of increasing demands for food and fuel in rapidly changing environmental conditions. Various transgenes have been introduced into either the nuclear or plastid genomes in attempts to increase photosynthetic efficiency. We examine the current knowledge of the critical features that affect levels of expression of plastid transgenes and protein accumulation in transplastomic plants, such as promoters, 5' and 3' untranslated regions, RNA-processing sites, translation signals and amino acid sequences that affect protein turnover. We review the prior attempts to manipulate the properties of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) through plastid transformation. We illustrate how plastid operons could be created for expression of the multiple genes needed to introduce new pathways or enzymes to enhance photosynthetic rates or reduce photorespiration. We describe here the past accomplishments and future prospects for manipulating plant enzymes and pathways to enhance carbon assimilation through plastid transformation. PMID:23162121

  16. AcEST: DK954126 [AcEST

    Lifescience Database Archive (English)

    Full Text Available VQEILQNLGYSLPIVGSISETSVSGIMSTCTHGSSLQHQVLPHYI 147 >sp|P55195|PUR6_VIGAC Phosphoribosylaminoimidazole carboxylase, chloroplas...e... 33 1.5 sp|Q9HDX8|ALO_SCHPO D-arabinono-1,4-lactone oxidase OS=Schizosac... 31 5.6 sp|P55195|PUR6_VIGAC Phosphoribosylaminoimidaz...|Y5516_ARATH Probable receptor kinase At5g05160 OS=Arabidopsis thaliana GN=At5g05...IP Sbjct: 65 TCD--ESNPTSRVVAVRLPGVGLYGSIP 90 >sp|Q9LVI6|RLK90_ARATH Probable inactive receptor kinase RLK902 OS=Arabidopsis thaliana...|P43298|TMK1_ARATH Putative receptor protein kinase TMK1 OS=Arabidopsis thaliana GN=TMK1 PE=1 SV=1 Length =

  17. Interactions of protein kinase CK2beta subunit within the holoenzyme and with other proteins

    DEFF Research Database (Denmark)

    Kusk, M; Ahmed, R; Thomsen, B;

    1999-01-01

    Protein kinase CK2 is a ubiquitous, highly conserved protein kinase with a tetrameric alpha2beta2 structure. For the formation of this tetrameric complex a beta-alpha dimer seems to be a prerequisite. Using the two-hybrid system and a series of CK2beta deletion mutants, we mapped domains involved...... in alpha-beta and beta-beta interactions. We also detected an intramolecular beta interaction within the amino acid stretch 132-165. Using CK2beta as a bait in a two-hybrid library screening several new putative cellular partners have been identified, among them the S6 kinase p90rsk, the putative...... tumor suppressor protein Doc-1, the Fas-associated protein FAF1, the mitochondrial translational initiation factor 2 and propionyl CoA carboxylase beta subunit....

  18. Cell Membrane Softening in Cancer Cells

    Science.gov (United States)

    Schmidt, Sebastian; Händel, Chris; Käs, Josef

    Biomechanical properties are useful characteristics and regulators of the cell's state. Current research connects mechanical properties of the cytoskeleton to many cellular processes but does not investigate the biomechanics of the plasma membrane. We evaluated thermal fluctuations of giant plasma membrane vesicles, directly derived from the plasma membranes of primary breast and cervical cells and observed a lowered rigidity in the plasma membrane of malignant cells compared to non-malignant cells. To investigate the specific role of membrane rigidity changes, we treated two cell lines with the Acetyl-CoA carboxylase inhibitor Soraphen A. It changed the lipidome of cells and drastically increased membrane stiffness by up regulating short chained membrane lipids. These altered cells had a decreased motility in Boyden chamber assays. Our results indicate that the thermal fluctuations of the membrane, which are much smaller than the fluctuations driven by the cytoskeleton, can be modulated by the cell and have an impact on adhesion and motility.

  19. The effect of exposure rate of the growth of soybean seedlings grown from gamma irradiated seeds

    International Nuclear Information System (INIS)

    The effect of the gamma (137Cs) total exposure rate of 25 kR delivered at three different exposure rates (887 R/min, 159 R/min and 48 R/min) on soybean seeds was studied by measuring seedling height, cotyledon area, fresh weight, dry weight, Co2 fixation and RuDP carboxylase activity. The dry weight, CO2 fixation and irradiated imbibed groups did not show any correlation with exposure rate. Exposure rate effect was shown for the first stage out, no further correlation was observed in the subsequent stages, probably due to the recovery and repair mechanisms that take place as the seedling increases with age. The absence of an exposure rate effect on irradiated imbibed group may be explained in terms of non-detectable damage at a very high dose, since these seedlings exhibited effects that are similar to the effects of seeds exposed to an acute radiation dose. (author)

  20. Ketogenic Diet: An Early Option for Epilepsy Treatment, Instead of A Last Choice Only

    Directory of Open Access Journals (Sweden)

    Huei-Shyong Wang

    2012-02-01

    Full Text Available Ketogenic diet (KD was usually tried as a last resort in the treatment of intractable epilepsy after failure of many antiepileptics and even epilepsy surgery. Glucose transporter-1 deficiency and pyruvate dehydrogenase deficiency must be treated with KD as the first choice because of inborn errors of glucose metabolism. Infantile spasms, tuberous sclerosis complex, Rett syndrome, Doose syndrome, Dravet syndrome, etc., appear to respond to KD, and it has been suggested by the international consensus statement to use KD early. We believe that all patients with epilepsy, except those with contraindicated situations such as pyruvate carboxylase deficiency, porphyria, β-oxidation defects, primary carnitine deficiency, etc., may try KD before trying other regimens.

  1. Sethoxydim treatment inhibits lipid metabolism and enhances the accumulation of anthocyanins in rape (Brassica napus L.) leaves.

    Science.gov (United States)

    Belkebir, Aicha; Benhassaine-Kesri, Ghouziel

    2013-09-01

    Cyclohexanediones (e.g., sethoxydim) are known to be inhibitors of plastid acetyl-CoA carboxylase (ACCase) of monocotyledonous plants and provoke plant death. When rape leaves were treated with 10(-3) M sethoxydim, growth rate, chlorophyll and lipid contents were reduced, but plant resisted to herbicide. [1-(14)C] Acetate labelling showed that lipid synthesis was affected by sethoxydim, probably through inhibition of chloroplast homomeric ACCase activity, and the fatty acid synthase activity (FAS) was reduced because of malonyl-CoA deficiency. In contrast, sethoxydim treatment provoked an increase in phenylalanine ammonia lyase (PAL) activity with an accumulation of cinnamic acid, naringenin and anthocyanins. The accumulation of anthocyanins seems to reduce the damaging effect of the herbicide stress. Thus, in plant cell, the flux of carbon seems to be oriented towards protective mechanisms, and the two ACCases could have an important role in this orientation. PMID:25149245

  2. L'Interactions entre la photorespiration avec le métabolisme primaire des feuilles d’Arabidopsis thaliana : Caractérisation de mutants pour la glycolate oxydase et la glutamate : glyoxylate aminotransférase 1

    OpenAIRE

    Dellero, Younès

    2015-01-01

    A la lumière, l’activité carboxylase de la RuBisCO permet de fixer le CO2 inorganique en matière organique, sous forme de 3-phosphoglycérate (3-PGA), qui sera utilisé pour la biosynthèse de sucres, d’acides organiques et aminés, de la paroi végétale etc. Cependant, elle possède aussi une activité oxygénase qui produit du 3-PGA et du 2-phosphoglycolate. Ce dernier composé étant toxique, il est métabolisé en 3-PGA par le cycle photorespiratoire qui se déroule dans le chloroplaste, le peroxysome...

  3. Neurofibromin interacts with CRMP-2 and CRMP-4 in rat brain

    International Nuclear Information System (INIS)

    Neurofibromin, encoded by the neurofibromatosis type 1 (NF1) gene, regulates the Ras and cAMP pathways and plays a role in proliferation and neuronal morphogenesis. The details of the molecular mechanism of neurofibromin action in these processes are still unclear. In this study, immunoprecipitation and proteomics were used to identify novel proteins from rat brain that interact with neurofibromin. Mass spectrometry analysis showed that two proteins, the collapsin response mediator protein-2 (CRMP-2) and propionyl-CoA carboxylase alpha chain (PCCA), associated with neurofibromin. Immunoprecipitation-immunoblotting analysis confirmed the interactions between neurofibromin and CRMP-2 and CRMP-4, but not CRMP-1, in rat brain. CDK5, a kinase that regulates CRMP-2 in axonal outgrowth, was required for the interaction between neurofibromin and CRMP-2. Since both neurofibromin and CRMP proteins are involved in proliferation and axonal morphogenesis, these results suggest that the interaction with CRMPs contributes to the function of neurofibromin in tumorigenesis and neuronal morphogenesis

  4. Enhanced insulin signaling in human skeletal muscle and adipose tissue following gastric bypass surgery

    DEFF Research Database (Denmark)

    Albers, Peter H; Bojsen-Møller, Kirstine N; Dirksen, Carsten;

    2015-01-01

    Roux-en-Y gastric bypass (RYGB) leads to increased peripheral insulin sensitivity. The aim of this study was to investigate the effect of RYGB on expression and regulation of proteins involved in regulation of peripheral glucose metabolism. Skeletal muscle and adipose tissue biopsies from glucose...... and glycogen synthase activity were enhanced 12 months post-surgery. In adipose tissue, protein expression of GLUT4, Akt2, TBC1D4 and acetyl-CoA carboxylase (ACC), phosphorylated levels of AMP-activated protein kinase and ACC as well as insulin-induced changes in phosphorylation of Akt and TBC1D4 were...... enhanced 12 months post-surgery. Adipose tissue from glucose tolerant subjects was the most responsive to RYGB compared to type 2 diabetic patients, whereas changes in skeletal muscle were largely similar in these two groups. In conclusion, an improved molecular insulin sensitive phenotype of skeletal...

  5. A molecular phylogeny of the heterokont algae based on analyses of choroplast-encoded rbcL sequence data

    DEFF Research Database (Denmark)

    Daugbjerg, Niels; Andersen, Robert A.

    1997-01-01

    Nearly complete ribulose-1,5-bisphosphate carboxylase/ oxygenase (rbcL)sequences from 27 taxa of heterokont algae were determined and combined with rbcL sequences obtained from GenBank for four other heterokont algae and three red algae. The phylogeny of the morphologically diverse haterokont algae...... was inferred from an unambiguously aligned data matrix using the red algae as the root, Significantly higher levels of mutational saturation in third codon positions were found when plotting the pair-wise substitutions with and without corrections for multiple substitutions at the same site for first...... algae. In addition, each carotenoid was mapped onto both the rbcL tree and a consensus tree derived from nuclear-encoded small-subunit ribosomal DNA (SSU rDNA) sequences. Carotenoid pigmentation does not provide unambiguous phylogenetic information, whether analyzed cladistically by itself or when...

  6. Extracting DNA from submerged pine wood.

    Science.gov (United States)

    Reynolds, M Megan; Williams, Claire G

    2004-10-01

    A DNA extraction protocol for submerged pine logs was developed with the following properties: (i) high molecular weight DNA, (ii) PCR amplification of chloroplast and nuclear sequences, and (iii) high sequence homology to voucher pine specimens. The DNA extraction protocol was modified from a cetyltrimehtylammonium bromide (CTAB) protocol by adding stringent electrophoretic purification, proteinase K, RNAse, polyvinyl pyrrolidone (PVP), and Gene Releaser. Chloroplast rbcL (ribulose-1,5-bisphosphate carboxylase) could be amplified. Nuclear ribosomal sequences had >95% homology to Pinus taeda and Pinus palustris. Microsatellite polymorphism for PtTX2082 matched 2 of 14 known P. taeda alleles. Our results show DNA analysis for submerged conifer wood is feasible. PMID:15499414

  7. Role of PGC-1{alpha} in exercise and fasting induced adaptations in mouse liver

    DEFF Research Database (Denmark)

    Haase, Tobias Nørresø; Jørgensen, Stine Ringholm; Leick, Lotte;

    2011-01-01

    The transcriptional coactivator peroxisome proliferator activated receptor (PPAR)-¿ coactivator (PGC)-1a plays a role in regulation of several metabolic pathways. By use of whole body PGC-1a knockout (KO) mice we investigated the role of PGC-1a in fasting, acute exercise and exercise training...... induced regulation of key proteins in gluconeogenesis and metabolism in the liver. In both wild type (WT) and PGC-1a KO mice liver, the mRNA content of the gluconeogenic proteins glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK) was upregulated during fasting. Pyruvate...... carboxylase (PC) remained unchanged after fasting in WT mice, but was upregulated in PGC-1a KO mice. In response to a single exercise bout G6Pase mRNA was upregulated in both genotypes, whereas no significant changes were detected in PEPCK or PC mRNA. While G6Pase and PC protein remained unchanged, liver...

  8. The complexity of chloroplast chaperonins.

    Science.gov (United States)

    Vitlin Gruber, Anna; Nisemblat, Shahar; Azem, Abdussalam; Weiss, Celeste

    2013-12-01

    Type I chaperonins are large oligomeric protein ensembles that are involved in the folding and assembly of other proteins. Chloroplast chaperonins and co-chaperonins exist in multiple copies of two distinct isoforms that can combine to form a range of labile oligomeric structures. This complex system increases the potential number of chaperonin substrates and possibilities for regulation. The incorporation of unique subunits into the oligomer can modify substrate specificity. Some subunits are upregulated in response to heat shock and some show organ-specific expression, whereas others possess additional functions that are unrelated to their role in protein folding. Accumulating evidence suggests that specific subunits have distinct roles in biogenesis of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco). PMID:24035661

  9. Pyruvate carboxylation enables growth of SDH-deficient cells by supporting aspartate biosynthesis.

    Science.gov (United States)

    Cardaci, Simone; Zheng, Liang; MacKay, Gillian; van den Broek, Niels J F; MacKenzie, Elaine D; Nixon, Colin; Stevenson, David; Tumanov, Sergey; Bulusu, Vinay; Kamphorst, Jurre J; Vazquez, Alexei; Fleming, Stewart; Schiavi, Francesca; Kalna, Gabriela; Blyth, Karen; Strathdee, Douglas; Gottlieb, Eyal

    2015-10-01

    Succinate dehydrogenase (SDH) is a heterotetrameric nuclear-encoded complex responsible for the oxidation of succinate to fumarate in the tricarboxylic acid cycle. Loss-of-function mutations in any of the SDH genes are associated with cancer formation. However, the impact of SDH loss on cell metabolism and the mechanisms enabling growth of SDH-defective cells are largely unknown. Here, we generated Sdhb-ablated kidney mouse cells and used comparative metabolomics and stable-isotope-labelling approaches to identify nutritional requirements and metabolic adaptations to SDH loss. We found that lack of SDH activity commits cells to consume extracellular pyruvate, which sustains Warburg-like bioenergetic features. We further demonstrated that pyruvate carboxylation diverts glucose-derived carbons into aspartate biosynthesis, thus sustaining cell growth. By identifying pyruvate carboxylase as essential for the proliferation and tumorigenic capacity of SDH-deficient cells, this study revealed a metabolic vulnerability for potential future treatment of SDH-associated malignancies. PMID:26302408

  10. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on Dietary Reference Values for biotin

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for biotin. Biotin is a water-soluble vitamin which serves as a co-factor for several carboxylases that play critical roles in the synthesis of...... and cannot be used for deriving DRVs for biotin. As there is insufficient evidence available to derive an Average Requirement and a Population Reference Intake, an Adequate Intake (AI) is proposed. The setting of AIs is based on observed biotin intakes with a mixed diet and the apparent absence of...... through breast milk. For infants over six months, an AI of 6 µg/day is proposed by extrapolating from the biotin intake of exclusively breastfed infants aged zero to six months, using allometric scaling and reference body weight for each age group, in order to account for the role of biotin in energy...

  11. Physiological characterization of the high malic acid-producing Aspergillus oryzae strain 2103a-68

    DEFF Research Database (Denmark)

    Knuf, Christoph; Nookaew, Intawat; Remmers, Ilse;

    2014-01-01

    Malic acid is a C4 dicarboxylic acid that is currently mainly used in the food and beverages industry as an acidulant. Because of the versatility of the group of C4 dicarboxylic acids, the chemical industry has a growing interest in this chemical compound. As malic acid will be considered as a bulk...... chemical, microbial production requires organisms that sustain high rates, yields, and titers. Aspergillus oryzae is mainly known as an industrial enzyme producer, but it was also shown that it has a very competitive natural production capacity for malic acid. Recently, an engineered A. oryzae strain, 2103......a-68, was presented which overexpressed pyruvate carboxylase, malate dehydrogenase, and a malic acid transporter. In this work, we report a detailed characterization of this strain including detailed rates and yields under malic acid production conditions. Furthermore, transcript levels of the genes...

  12. Regulation of Rubisco gene expression in C4 plants.

    Science.gov (United States)

    Berry, James O; Mure, Christopher M; Yerramsetty, Pradeep

    2016-06-01

    Ribulose-1,5-bisphosphate-carboxylase/oxygenase (Rubisco) incorporates inorganic carbon into an organic form, making this chloroplastic enzyme one of the most essential factors for all life on earth. Despite its central role in photosynthesis, research into regulation of the chloroplast rbcL and nuclear RbcS genes that encode this enzyme has lagged behind other plant gene systems. A major characteristic of kranz-type C4 plants is the accumulation of Rubisco only within chloroplasts of internalized bundle sheath cells that surround the leaf vascular centers. In plants that utilize the less common single cell C4 system, Rubisco accumulates only within one type of dimorphic chloroplasts localized to a specific region of leaf chlorenchyma cells. Understanding regulatory processes that restrict Rubisco gene expression to only one cell type or chloroplast type is a major focus of C4 research. Regulatory steps may include transcriptional, post-transcriptional, and post-translational processes. PMID:27026038

  13. Effect of pH and nitrogen source in carboxylation by seedlings of wheat and maize

    International Nuclear Information System (INIS)

    Carboxylation has been studied in leaves homogenate, expressed as RuBP-carboxylase activity, using as one of the substrates NaH14CO3, and giving the acitivity value as nanomols of 14CO2 incorporated by mg.. of protein per minute in the determined conditions. The variable is the pH of the culture media. Cultures has been studied with pH values between 3.5 and 6.2. Three different nitrogen sources has been used, carefully calculating the composition of each medium in order that all of them have same nitrogen content:1) Nitrate medium, 2) Ammonium sulfate medium and 3) Ammonium nitrate medium. The results are presented graphically with a discussion about them. It is shown that the effect of pH is less pronounced in maize that in wheat, with NO3 nitrogen source that with NH4+, and in plants 28 days age than in plants 7 days age. (author)

  14. The role of the glucose-sensing transcription factor carbohydrate-responsive element-binding protein pathway in termite queen fertility

    DEFF Research Database (Denmark)

    Sillam-Dussès, David; Hanus, Robert; Poulsen, Michael;

    2016-01-01

    Termites are among the few animals that themselves can digest the most abundant organic polymer, cellulose, into glucose. In mice and Drosophila, glucose can activate genes via the transcription factor carbohydrate-responsive element-binding protein (ChREBP) to induce glucose utilization and de...... novo lipogenesis. Here, we identify a termite orthologue of ChREBP and its downstream lipogenic targets, including acetyl-CoA carboxylase and fatty acid synthase. We show that all of these genes, including ChREBP, are upregulated in mature queens compared with kings, sterile workers and soldiers....... Suppression of the lipogenic pathway by a pharmacological agent in queens elicits the same behavioural alterations in sterile workers as observed in queenless colonies, supporting that the ChREBP pathway partakes in the biosynthesis of semiochemicals that convey the signal of the presence of a fertile queen...

  15. AcEST: DK953168 [AcEST

    Lifescience Database Archive (English)

    Full Text Available 3168|Adiantum capillus-veneris mRNA, clone: TST39A01NGRL0017_A24, 5' (612 letters) Datab...168 Tissue type prothallia with plantlets Developmental stage gametophytes with s...9-3402. Query= DK953168|Adiantum capillus-veneris mRNA, clone: TST39A01NGRL0017_A24, 5' (612 let...) Value sp|Q8MT36|MES4_DROME Probable histone-lysine N-methyltransferase... 30 9....7 sp|P04716|RBS_SYNP6 Ribulose bisphosphate carboxylase small chai... 30 9.8 >sp|Q8MT36|MES4_DROME Probable histone-lysine N-met

  16. The Role of Gamma Irradiation on Growth and Some Metabolic Activities of Spirulina platensis

    International Nuclear Information System (INIS)

    Spirulina platensis cells were exposed to different doses of gamma irradiation 0.0; (control), 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 Kilo Gray (kGy) using Co60 as a gamma source at the Cyclotron Unit, Nuclear Research Center, Egyptian Atomic Energy Authority. After which, the cells were cultivated on Zarrouk medium for 14 days (the exponential phase of growth). The optimum growth of Spirulina platensis was recorded at 2.0 kGy as compared to the control after the 14th day of incubation. All of the following analyses were done after 10 days of growth. The results of pigments analysis revealed that the chlorophyll a and carotenoid contents of Spirulina platensis were reached their maximum rate at a dose of 2.0 kGy, Which induces the same trend for phycobiliproteins fractions. The photosynthetic activity and total carbohydrate content of the irradiated Spirulina cells increased with elevating the doses of gamma irradiation and reached a maximum value at a dose of 2.0 kGy as compared to the control. The activity of ribulose-1,5-bisphosphate-carboxylase/oxygenase (RUBISCO) was increased up to irradiation dose of 2.0 kGy. whereas, the maximum activity of the phosphoenol pyruvate carboxylase (PEPCASE) was recorded at the irradiation dose of 1.0 kGy Spirulina platensis cells were exposed to different doses of gamma irradiation 0.0; (control), 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 Kilo Gray (kGy) using Co60 as a gamma source at the Cyclotron Unit, Nuclear Research Center, Egyptian Atomic Energy Authority. After which, the cells were cultivated on Zarrouk medium for 14 days (the exponential phase of growth). The optimum growth of Spirulina platensis was recorded at 2.0 kGy as compared to the control after the 14th day of incubation. All of the following analyses were done after 10 days of growth. The results of pigments analysis revealed that the chlorophyll a and carotenoid contents of Spirulina platensis were reached their maximum rate at a dose of 2.0 kGy, Which induces the same trend

  17. Undaria pinnatifida and Fucoxanthin Ameliorate Lipogenesis and Markers of Both Inflammation and Cardiovascular Dysfunction in an Animal Model of Diet-Induced Obesity

    Science.gov (United States)

    Grasa-López, Ameyalli; Miliar-García, Ángel; Quevedo-Corona, Lucía; Paniagua-Castro, Norma; Escalona-Cardoso, Gerardo; Reyes-Maldonado, Elba; Jaramillo-Flores, María-Eugenia

    2016-01-01

    Brown algae and its carotenoids have been shown to have a positive influence on obesity and its comorbidities. This study evaluated the effect of Undaria pinnatifida and fucoxanthin on biochemical, physiological and inflammation markers related to obesity and on the expression of genes engaged on white adipose tissue lipid metabolism in a murine model of diet-induced obesity. The treatments improved energy expenditure, β-oxidation and adipogenesis by upregulating PPARα, PGC1α, PPARγ and UCP-1. Adipogenesis was also confirmed by image analysis of the retroperitoneal adipose tissue, by measuring cell area, perimeter and cellular density. Additionally, the treatments, ameliorated adipose tissue accumulation, insulin resistance, blood pressure, cholesterol and triglycerides concentration in serum, and reduced lipogenesis and inflammation by downregulating acetyl-CoA carboxylase (ACC) gene expression, increasing serum concentration and expression of adiponectin as well as downregulating IL-6 expression. Both fucoxanthin and Undaria pinnatifida may be considered for treating obesity and other diseases related. PMID:27527189

  18. Body weight management effect of burdock (Arctium lappa L.) root is associated with the activation of AMP-activated protein kinase in human HepG2 cells.

    Science.gov (United States)

    Kuo, Daih-Huang; Hung, Ming-Chi; Hung, Chao-Ming; Liu, Li-Min; Chen, Fu-An; Shieh, Po-Chuen; Ho, Chi-Tang; Way, Tzong-Der

    2012-10-01

    Burdock (Arcticum lappa L.) root is used in folk medicine and also as a vegetable in Asian countries. In the present study, burdock root treatment significantly reduced body weight in rats. To evaluate the bioactive compounds, we successively extracted the burdock root with ethanol (AL-1), and fractionated it with n-hexane (AL-2), ethyl acetate (AL-3), n-butanol (AL-4), and water (AL-5). Among these fractions, AL-2 contained components with the most effective hypolipidemic potential in human hepatoma HepG2 cells. AL-2 decreased the expression of fatty acid synthase (FASN) and inhibited the activity of acetyl-coenzyme A carboxylase (ACC) by stimulating AMP-activated protein kinase (AMPK) through the LKB1 pathway. Three active compounds were identified from the AL-2, namely α-linolenic acid, methyl α-linolenate, and methyl oleate. These results suggest that burdock root is expected to be useful for body weight management. PMID:25005949

  19. AcEST: DK959970 [AcEST

    Lifescience Database Archive (English)

    Full Text Available ate carboxylase small chai... 44 8e-04 sp|P51335|MOEB_PORPU Probable molybdopterin biosynthesis protein... 4...inghui Zhang, Zheng Zhang, Webb Miller, and David J. Lipman (1997), Gapped BLAST and PSI-BLAST: a new generation of protein databa...-veneris mRNA, clone: TST39A01NGRL0006_C03, 5' (596 letters) Database: uniprot_spro..._SALTY Molybdopterin biosynthesis protein moeB OS=... 44 5e-04 sp|P18500|HESA_ANASP Protein hesA OS=Anabaena...Ubiquitin-activating enzyme E1-like OS=Schizosaccharomyces pombe GN=uba2 PE=1 SV=1 Length = 628 Score = 47.8

  20. Genetic Disruption of Protein Kinase STK25 Ameliorates Metabolic Defects in a Diet-Induced Type 2 Diabetes Model

    DEFF Research Database (Denmark)

    Amrutkar, Manoj; Cansby, Emmelie; Chursa, Urszula;

    2015-01-01

    Understanding the molecular networks controlling ectopic lipid deposition, glucose tolerance, and insulin sensitivity is essential to identifying new pharmacological approaches to treat type 2 diabetes. We recently identified serine/threonine protein kinase 25 (STK25) as a negative regulator of...... glucose and insulin homeostasis based on observations in myoblasts with acute depletion of STK25 and in STK25-overexpressing transgenic mice. Here, we challenged Stk25 knockout mice and wild-type littermates with a high-fat diet and showed that STK25 deficiency suppressed development of hyperglycemia and...... hyperinsulinemia, improved systemic glucose tolerance, reduced hepatic gluconeogenesis, and increased insulin sensitivity. Stk25−/− mice were protected from diet-induced liver steatosis accompanied by decreased protein levels of acetyl-CoA carboxylase, a key regulator of both lipid oxidation and synthesis. Lipid...

  1. [Pharmacogenetics of warfarin].

    Science.gov (United States)

    Kessler, P

    2006-03-01

    There are significant differences among patients treated with warfarin in the dosage volumes necessary to reach an optimum therapeutic effect. Apart from the external influences (interactions with drugs and food), genetic predispositions play an important role. Polymorphysms of the P 450 2C9 cytochrome bear upon the speed ofbreaking down S-warfarin, polymorfysms VKORC1 bear on the volume and quality of epoxide reductase--an enzyme whose blockade is the crux of the mechanism how cumarin anticoagulants act. These two genes are responsible for at least 50% of the warfarin effect variability. Warfarin's effect is further determined by the genetic variants of gamma-carboxylase, prothrombin, factors VII and IX. In near future, further results of pharmacogenetic research and clinical studies can be expected. They study the impact of the findings in clinical practice. PMID:16637447

  2. Undaria pinnatifida and Fucoxanthin Ameliorate Lipogenesis and Markers of Both Inflammation and Cardiovascular Dysfunction in an Animal Model of Diet-Induced Obesity.

    Science.gov (United States)

    Grasa-López, Ameyalli; Miliar-García, Ángel; Quevedo-Corona, Lucía; Paniagua-Castro, Norma; Escalona-Cardoso, Gerardo; Reyes-Maldonado, Elba; Jaramillo-Flores, María-Eugenia

    2016-01-01

    Brown algae and its carotenoids have been shown to have a positive influence on obesity and its comorbidities. This study evaluated the effect of Undaria pinnatifida and fucoxanthin on biochemical, physiological and inflammation markers related to obesity and on the expression of genes engaged on white adipose tissue lipid metabolism in a murine model of diet-induced obesity. The treatments improved energy expenditure, β-oxidation and adipogenesis by upregulating PPARα, PGC1α, PPARγ and UCP-1. Adipogenesis was also confirmed by image analysis of the retroperitoneal adipose tissue, by measuring cell area, perimeter and cellular density. Additionally, the treatments, ameliorated adipose tissue accumulation, insulin resistance, blood pressure, cholesterol and triglycerides concentration in serum, and reduced lipogenesis and inflammation by downregulating acetyl-CoA carboxylase (ACC) gene expression, increasing serum concentration and expression of adiponectin as well as downregulating IL-6 expression. Both fucoxanthin and Undaria pinnatifida may be considered for treating obesity and other diseases related. PMID:27527189

  3. Characterization of photorespiration and photosynthesis in soybean cotyledons during seedling development, cotyledon senescence and rejuvenation

    International Nuclear Information System (INIS)

    We measured light and dark carbon dioxide exchange rates (CER) in germinating, presenescent, and senescing soybean cotyledons and in cotyledons rejuvenated by epicotyl removal on different days after planting. In other aspects of cotyledon physiology, we observed significant differences between rejuvenated and presenescent soybean cotyledons. Rejuvenated cotyledons accumulated chlorophyll to levels greater than the maximal amount measured in presenescent cotyledons. A second difference was the observation that during rejuvenation, the post-illumination outburst of CO2 (the PIB), a qualitative indication of photorespiration, appeared to recover more slowly than light CER when compared with presenescent but equivalent light CERs. To investigate the relationship between the PIB and light CER, we labelled cotyledons with 14CO2 during photosynthesis. We measured the amount of ribulose-1,5-bisphosphate carboxylase oxygenase (RubisCO) in the cotyledons by rocket immunoelectrophoresis

  4. Salinity and Salicylic Acid Interactions in Affecting Nitrogen Assimilation, Enzyme Activity, Ions Content and Translocation Rate of Maize Plants

    International Nuclear Information System (INIS)

    This study was carried out to establish the relationship between nitrogen metabolism, enzyme activity, ions concentration as well as the translocation rate (TR) of carbohydrates and salicylic acid (SA) in salt-stressed maize (Zea mays L). Salicylic acid plus salinity treatment highly significantly increased: nucleic acids (DNA and RNA), protein content, phosphoenolpyruvate carboxylase (PEPCase) and nitrate reductase (NR) and inhibited nucleases (DNase and RNase) activities compared with Na CI-treated plants. In addition, the ionic levels of potassium (K), phosphorus (P), nitrate (NO3) and the translocation rate of the labelled photo assimilates have also been stimulated while sodium (Na) ions content was decreased. It is concluded that, salinazid maize plants might show an enhancement in their growth pattern upon salicylic acid application

  5. The glycolytic shift in fumarate-hydratase-deficient kidney cancer lowers AMPK levels, increases anabolic propensities and lowers cellular iron levels

    KAUST Repository

    Tong, Winghang

    2011-09-01

    Inactivation of the TCA cycle enzyme, fumarate hydratase (FH), drives a metabolic shift to aerobic glycolysis in FH-deficient kidney tumors and cell lines from patients with hereditary leiomyomatosis renal cell cancer (HLRCC), resulting in decreased levels of AMP-activated kinase (AMPK) and p53 tumor suppressor, and activation of the anabolic factors, acetyl-CoA carboxylase and ribosomal protein S6. Reduced AMPK levels lead to diminished expression of the DMT1 iron transporter, and the resulting cytosolic iron deficiency activates the iron regulatory proteins, IRP1 and IRP2, and increases expression of the hypoxia inducible factor HIF-1α, but not HIF-2α. Silencing of HIF-1α or activation of AMPK diminishes invasive activities, indicating that alterations of HIF-1α and AMPK contribute to the oncogenic growth of FH-deficient cells. © 2011 Elsevier Inc.

  6. Ethanolic Extract of Vitis thunbergii Exhibits Lipid Lowering Properties via Modulation of the AMPK-ACC Pathway in Hypercholesterolemic Rabbits

    Directory of Open Access Journals (Sweden)

    Chun-Hsu Pan

    2012-01-01

    Full Text Available Vitis thunbergii (VT is a wild grape that has been shown to provide various cardioprotective effects. The present study was designed to examine whether a VT extract could reduce serum lipid levels and prevent atherogenesis in a hypercholesterolemic rabbit model. At the end of an 8-week study, our results showed that a VT extract supplement markedly suppressed the serum levels of cholesterol and low-density lipoprotein, reduced lipid accumulation in liver tissues, and limited aortic fatty streaks. Our findings suggest that the VT extract activated AMPK (5′-adenosine monophosphate-activated protein kinase with subsequent inhibition of the activation of ACC (acetyl-CoA carboxylase. Our results suggest that this VT extract could be further developed as a potential lipid-lowering agent and as a natural health food to prevent atherogenesis.

  7. AcEST: DK961866 [AcEST

    Lifescience Database Archive (English)

    Full Text Available ste... 96 3e-18 tr|B4Y0U0|B4Y0U0_MEDTR Isoflavonoid malonyl transferase 1 OS=M...5 >tr|B4Y0U0|B4Y0U0_MEDTR Isoflavonoid malonyl transferase 1 OS=Medicago truncatula GN=MAT1 PE=2 SV=1 Length...nesis protein BMS1 OS=Sacchar... 31 5.4 sp|O74197|PUR6_CANGA Phosphoribosylaminoimidazole carboxylase OS... ... J. Lipman (1997), Gapped BLAST and PSI-BLAST: a new generation of protein database search programs, Nucleic Acids... scutellarioides GN=cbhct1 PE=2 SV=1 Length = 430 Score = 95.5 bits (236), Expect = 3e-

  8. AcEST: DK962877 [AcEST

    Lifescience Database Archive (English)

    Full Text Available e-18 tr|B4Y0U0|B4Y0U0_MEDTR Isoflavonoid malonyl transferase 1 OS=Med... 88 6e-16 tr|A9S7S1|A9S7S1_PHYPA Pre... L G A + PH R L + +P Q Sbjct: 166 TWAHLSRGAPAPTPLPHFDRSSLSARNPPQ 195 >tr|B4Y0U0|B4Y0U0_MEDTR Isoflavonoid malon... RGSSVICLPPSHDR 211 >tr|A0PDV5|A0PDV5_SOLSC Hydroxycinnamoyl transferase OS=Solenostemon scutellarioid...ar... 31 5.2 sp|O74197|PUR6_CANGA Phosphoribosylaminoimidazole carboxylase OS... 31 6.8 sp|Q9H0B3|K1683_HUMA...base search programs, Nucleic Acids Res. 25:3389-3402. Query= DK962877|Adiantum c

  9. Crystallization and Characterization of Galdieria sulphuraria RUBISCO in Two Crystal Forms: Structural Phase Transition Observed in P21 Crystal Form

    Directory of Open Access Journals (Sweden)

    Boguslaw Stec

    2007-10-01

    Full Text Available We have isolated ribulose-1,5-bisphosphate-carboxylase/oxygenase (RUBISCOfrom the red algae Galdieria Sulphuraria. The protein crystallized in two different crystalforms, the I422 crystal form being obtained from high salt and the P21 crystal form beingobtained from lower concentration of salt and PEG. We report here the crystallization,preliminary stages of structure determination and the detection of the structural phasetransition in the P21 crystal form of G. sulphuraria RUBISCO. This red algae enzymebelongs to the hexadecameric class (L8S8 with an approximate molecular weight 0.6MDa.The phase transition in G. sulphuraria RUBISCO leads from two hexadecamers to a singlehexadecamer per asymmetric unit. The preservation of diffraction power in a phasetransition for such a large macromolecule is rare.

  10. DCP — EDRN Public Portal

    Science.gov (United States)

    Des-gamma-carboxy prothrombin (DCP) is a non-functional precursor of prothrombin. Prothrombin, produced by the liver, serves a critical role in normal hemostasis. Functional prothrombin contains several gamma-carboxy-glutamic acid (Gla) residues that are produced as the result of post-translational modification of glutamic acid residues mediated by vitamin K dependent gamma-glutamyl carboxylase. The formation of Gla residues can be impaired in patients with vitamin K deficiency or in patients receiving oral anticoagulant therapy. DCP lacks thrombotic activity and has been shown in multiple studies to be present in the serum of patients with HCC. DCP arises from an acquired defect in the post-translational carboxylation of the pro-thrombin precursor in malignant hepatocytes.

  11. The capacity of phototrophic sulfur bacterium Thiocapsa roseopersicina for chemosynthesis.

    Science.gov (United States)

    Kondratieva, E N; Zhukov, V G; Ivanovsky, R N; Petushkova, U P; Monosov, E Z

    1976-07-01

    Purple sulfur bacterium Thiocapsa roseopersicina strain BBS requiring vitamin B12 may grow in the dark in media containing no other organic compounds. Under such conditions the cells oxidize sulfide and thiosulfate with the use of O2 and assimilate carbon dioxide. After 10--30s assimilation of NaH14CO3 about 60% of radioactivity is found in phosphorylated compounds characteristic for the reductive pentose phosphate cycle. The possibility of the function of this cycle in the dark in the presence of O2 is confirmed by the capacity of cells grown under such conditions to synthesize ribulose-1,5-diphosphate carboxylase. All this evidence suggests the ability of T. roseopersicina to change from phototrophy to aerobic chemolithoautotrophy. PMID:942280

  12. AcEST: DK945609 [AcEST

    Lifescience Database Archive (English)

    Full Text Available = DK945609|Adiantum capillus-veneris mRNA, clone: YMU02A01NGRL0009_O04, 5' (309 letters) Database: uniprot_spr...y10Aa OS=Baci... 32 0.75 sp|Q9BYV9|BACH2_HUMAN Transcription regulator protein BACH2 OS=H... 32 0.99 sp...EYGHMLVQEQENVKRVQLADKY 403 >sp|Q7X9A0|RCA1_LARTR Ribulose bisphosphate carboxylase/oxygenase activase 1, chloroplastic OS=Larrea tri...609|Adiantum capillus-veneris mRNA, clone: YMU02A01NGRL0009_O04, 5' (309 letters) Database: uniprot_trembl.f........done Score E Sequences producing significant alignments: (bits) Value tr|Q9AXG1|Q9AXG1_GOSHI Ribulose-1,5-bisphosp

  13. Accumulation of fatty acids in Chlorella vulgaris under heterotrophic conditions in relation to activity of acetyl-CoAcarboxylase, temperature, and co-immobilization with Azospirillum brasilense [corrected].

    Science.gov (United States)

    Leyva, Luis A; Bashan, Yoav; Mendoza, Alberto; de-Bashan, Luz E

    2014-10-01

    The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae. PMID:25129521

  14. The biosynthesis of erucic acid in developing embryos of Brassica rapus

    International Nuclear Information System (INIS)

    The prevailing hypothesis on the biosynthesis of erucic acid in developing seeds is that oleic acid, produced in the plastid, is activated to oleoyl-coenzyme A (CoA) for malonyl-CoA-dependent elongation to erucic acid in the cytosol. Several in vivo-labeling experiments designed to probe and extend this hypothesis are reported here. To examine whether newly synthesized oleic acid is directly elongated to erucic acid in developing seeds of Brassica rapa L., embryos were labeled with [14C]acetate, and the ratio of radioactivity of carbon atoms C-5 to C-22 (de novo fatty acid synthesis portion) to carbon atoms C-1 to C-4 (elongated portion) of erucic acid was monitored with time. If newly synthesized 18:1 (oleate) immediately becomes a substrate for elongation to erucic acid, this ratio would be expected to remain constant with incubation time. However, if erucic acid is produced from a pool of preexisting oleic acid, the ratio of 14C in the 4 elongation carbons to 14C in the methyl-terminal 18 carbons would be expected to decrease with time. This labeling ratio decreased with time and, therefore, suggests the existence of an intermediate pool of 18:1, which contributes at least part of the oleoyl precursor for the production of erucic acid. The addition of 2-[(3-chloro-5-(trifluromethyl)-2-pyridinyl) oxyphenoxy]propanoic acid, which inhibits the homodimeric acetyl-CoA carboxylase, severely inhibited the synthesis of [14C]erucic acid, indicating that essentially all malonyl-CoA for elongation of 18:1 to erucate was produced by homodimeric acetyl-CoA carboxylase. Both light and 2-[(3-chloro-5(trifluromethyl)-2-pyridinyl) oxyphenoxy]-propanoic acid increased the accumulation of [14C]18:1 and the parallel accumulation of [14C]phosphatidylcholine. Taken together, these results show an additional level of complexity in the biosynthesis of erucic acid

  15. Palmitate attenuates osteoblast differentiation of fetal rat calvarial cells

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Lee-Chuan C.; Ford, Jeffery J. [Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX (United States); Lee, John C. [Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX (United States); The Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, TX (United States); Adamo, Martin L., E-mail: adamo@biochem.uthscsa.edu [Department of Biochemistry, The University of Texas Health Science Center at San Antonio, TX (United States); The Sam and Ann Barshop Institute for Longevity and Aging Studies, The University of Texas Health Science Center at San Antonio, TX (United States)

    2014-07-18

    Highlights: • Palmitate inhibits osteoblast differentiation. • Fatty acid synthase. • PPARγ. • Acetyl Co-A carboxylase inhibitor TOFA. • Fetal rat calvarial cell culture. - Abstract: Aging is associated with the accumulation of ectopic lipid resulting in the inhibition of normal organ function, a phenomenon known as lipotoxicity. Within the bone marrow microenvironment, elevation in fatty acid levels may produce an increase in osteoclast activity and a decrease in osteoblast number and function, thus contributing to age-related osteoporosis. However, little is known about lipotoxic mechanisms in intramembraneous bone. Previously we reported that the long chain saturated fatty acid palmitate inhibited the expression of the osteogenic markers RUNX2 and osteocalcin in fetal rat calvarial cell (FRC) cultures. Moreover, the acetyl CoA carboxylase inhibitor TOFA blocked the inhibitory effect of palmitate on expression of these two markers. In the current study we have extended these observations to show that palmitate inhibits spontaneous mineralized bone formation in FRC cultures in association with reduced mRNA expression of RUNX2, alkaline phosphatase, osteocalcin, and bone sialoprotein and reduced alkaline phosphatase activity. The effects of palmitate on osteogenic marker expression were inhibited by TOFA. Palmitate also inhibited the mRNA expression of fatty acid synthase and PPARγ in FRC cultures, and as with osteogenic markers, this effect was inhibited by TOFA. Palmitate had no effect on FRC cell proliferation or apoptosis, but inhibited BMP-7-induced alkaline phosphatase activity. We conclude that palmitate accumulation may lead to lipotoxic effects on osteoblast differentiation and mineralization and that increases in fatty acid oxidation may help to prevent these lipotoxic effects.

  16. Impeded Carbohydrate Metabolism in Rice Plants under Submergence Stress

    Institute of Scientific and Technical Information of China (English)

    Malay Kumar ADAK; Nirmalya GHOSH; Dilip Kumar DASGUPTA; Sudha GUPTA

    2011-01-01

    The detrimental effects of submergence on physiological performances of some rice varieties with special references to carbohydrate metabolisms and their allied enzymes during post-flowering stages have been documented and clarified in the present investigation.It was found that photosynthetic rate and concomitant translocation of sugars into the panicles were both related to the yield.The detrimental effects of the complete submergence were recorded in generation of sucrose,starch,sucrose phosphate synthase and phosphorylase activity in the developing panicles of the plants as compared to those under normal or control (i.e.non-submerged) condition.The accumulation of starch was significantly lower in plants under submergence and that was correlated with ADP-glucose pyrophosphorylase activity.Photosynthetic rate was most affected under submergence in varying days of post-flowering and was also related to the down regulation of Ribulose bisphosphate carboxylase activity.However,under normal or control condition,there recorded a steady maintenance of photosynthetic rate at the post-flowering stages and significantly higher values of Ribulose bisphosphate carboxylase activity.Still,photosynthetic rate of the plants under both control and submerged conditions had hardly any significant correlation with sugar accumulation and other enzymes of carbohydrate metabolism like invertase with grain yield.Finally,plants under submergence suffered significant loss of yield by poor grain filling which was related to impeded carbohydrate metabolism in the tissues.It is evident that loss of yield under submergence is attributed both by lower sink size or sink capacity (number of panicles,in this case) as well as subdued carbohydrate metabolism in plants and its subsequent partitioning into the grains.

  17. Changes in C-N metabolism under elevated CO2 and temperature in Indian mustard (Brassica juncea L.): an adaptation strategy under climate change scenario.

    Science.gov (United States)

    Seth, Chandra Shekhar; Misra, Virendra

    2014-11-01

    The present study was performed to investigate the possible role of carbon (C) and nitrogen (N) metabolism in adaptation of Indian mustard (Brassica juncea L.) growing under ambient (370 ± 15 ppm) and elevated CO2 (700 ± 15 ppm), and jointly in elevated CO2 and temperature (30/22 °C for day/night). The key enzymes responsible for C-N metabolism were studied in different samples of Brassica juncea L. collected from ambient (AMB), elevated (ELE) and ELExT growth conditions. Total percent amount of C and N in leaves were particularly estimated to establish a clear understanding of aforesaid metabolism in plant adaptation. Furthermore, key morphological and physiological parameters such as plant height, leaf area index, dry biomass, net photosynthetic rate, stomatal conductance, transpiration, total protein and chlorophyll contents were also studied in relation to C/N metabolism. The results indicated that the C-metabolizing enzymes, such as (ribulose-1,5-bisphosphate carboxylase/oxygenase, phosphoenolpyruvate carboxylase, malate dehydrogenase, NAD-malic enzyme, NADP-malic enzyme and citrate synthase) and the N-metabolizing enzymes, such as (aspartate amino transferase, glutamine synthetase, nitrate reductase and nitrite reductase) showed significantly (P ELE > ELExT > AMB growth conditions. This is also evident by significant (P < 0.05) increase in percent contents of C and N in leaves as per said order. These findings suggested that improved performance of C-N metabolism could be a possible approach for CO2 assimilation and adaptation in Brassica juncea L. against elevated CO2 and temperature prevailing in climate change scenarios. PMID:25246072

  18. Phaeodactylum tricornutum photosynthesis and Thalassiosira pseudonana bio-silica formation genes nucleotide fluctuations

    Science.gov (United States)

    Holden, Todd; Marchese, P.; Tremberger, G., Jr.; Cheung, E.; Subramaniam, R.; Sullivan, R.; Schneider, P.; Flamholz, A.; Huerta, M.; Lieberman, D.; Cheung, T.

    2008-08-01

    Diatom bioactivity has been reported to be responsible for about 20% of carbon fixation globally and together with other photosynthetic organisms, the bioactivity can be monitored via satellite ocean imaging. The bioinformatics embedded in the nucleotide fluctuations of photosynthesis and bio-silicate genes in diatoms were studied. The recently reported phosphoenolpyruvate carboxylase PEPC1 and PEPC2 C4-like photosynthesis genes in Phaeodactylum tricornutum were found to have similar fractal dimensions of about 2.01. In comparison, the green alga Chlamydomonas reinhardtii PEPC1 and PEPC2 genes have fractal dimensions of about 2.05. The PEPC CpG dinucleotide content is 8% in P. tricornutum and 10% in C. reinhardtii. Further comparison of the cell wall protein gene showed that the VSP1 gene sequence in C. reinhardtii has a fractal dimension of 2.03 and the bio-silica formation silaffin gene in Thalassiosira pseudonana has a fractal dimension of 2.01. The phosphoenolpyruvate carboxylase PPC1 and PPC2 in T. pseudonana were found to have fractal dimensions and CpG dinucleotide content similar to that of P. tricornutum. The fractal dimension of the dnaB replication helicase gene is about 1.98 for both diatoms as well as for the alga Heterosigma akashiwo. In comparison, the E. coli dnaB gene has a fractal dimension of about 2.03. Given that high fractal dimension and CpG dinucleotide content sequences have been associated with the presence of selective pressures, the relatively low fractal dimension gene sequences of the two unique properties of Earth-bound diatoms (photosynthesis and bio-silica cell wall) suggests the potential for the development of high fractal dimension sequences for adaptation in harsh environments.

  19. Palmitate attenuates osteoblast differentiation of fetal rat calvarial cells

    International Nuclear Information System (INIS)

    Highlights: • Palmitate inhibits osteoblast differentiation. • Fatty acid synthase. • PPARγ. • Acetyl Co-A carboxylase inhibitor TOFA. • Fetal rat calvarial cell culture. - Abstract: Aging is associated with the accumulation of ectopic lipid resulting in the inhibition of normal organ function, a phenomenon known as lipotoxicity. Within the bone marrow microenvironment, elevation in fatty acid levels may produce an increase in osteoclast activity and a decrease in osteoblast number and function, thus contributing to age-related osteoporosis. However, little is known about lipotoxic mechanisms in intramembraneous bone. Previously we reported that the long chain saturated fatty acid palmitate inhibited the expression of the osteogenic markers RUNX2 and osteocalcin in fetal rat calvarial cell (FRC) cultures. Moreover, the acetyl CoA carboxylase inhibitor TOFA blocked the inhibitory effect of palmitate on expression of these two markers. In the current study we have extended these observations to show that palmitate inhibits spontaneous mineralized bone formation in FRC cultures in association with reduced mRNA expression of RUNX2, alkaline phosphatase, osteocalcin, and bone sialoprotein and reduced alkaline phosphatase activity. The effects of palmitate on osteogenic marker expression were inhibited by TOFA. Palmitate also inhibited the mRNA expression of fatty acid synthase and PPARγ in FRC cultures, and as with osteogenic markers, this effect was inhibited by TOFA. Palmitate had no effect on FRC cell proliferation or apoptosis, but inhibited BMP-7-induced alkaline phosphatase activity. We conclude that palmitate accumulation may lead to lipotoxic effects on osteoblast differentiation and mineralization and that increases in fatty acid oxidation may help to prevent these lipotoxic effects

  20. Enhanced chloroplastic generation of H2O2 in stress-resistant Thellungiella salsuginea in comparison to Arabidopsis thaliana.

    Science.gov (United States)

    Wiciarz, Monika; Gubernator, Beata; Kruk, Jerzy; Niewiadomska, Ewa

    2015-03-01

    In order to find some basis of salinity resistance in the chloroplastic metabolism, a halophytic Thellungiella salsuginea was compared with glycophytic Arabidopsis thaliana. In control T.s. plants the increased ratios of chlorophyll a/b and of fluorescence emission at 77 K (F730 /F685 ) were documented, in comparison to A.t.. This was accompanied by a higher YII and lower NPQ (non-photochemical quenching) values, and by a more active PSI (photosystem I). Another prominent feature of the photosynthetic electron transport (PET) in T.s. was the intensive production of H2 O2 from PQ (plastoquinone) pool. Salinity treatment (0.15 and 0.30 M NaCl for A.t. and T.s., respectively) led to a decrease in ratios of chl a/b and F730 /F685 . In A.t., a salinity-driven enhancement of YII and NPQ was found, in association with the stimulation of H2 O2 production from PQ pool. In contrast, in salinity-treated T.s., these variables were similar as in controls. The intensive H2 O2 generation was accompanied by a high activity of PTOX (plastid terminal oxidase), whilst inhibition of this enzyme led to an increased H2 O2 formation. It is hypothesized, that the intensive H2 O2 generation from PQ pool might be an important element of stress preparedness in Thellungiella plants. In control T.s. plants, a higher activation state of carboxylase ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) was also documented in concert with the attachment of Rubisco activase (RCA) to the thylakoid membranes. It is supposed, that a closer contact of RCA with PSI in T.s. enables a more efficient Rubisco activation than in A.t. PMID:24961163

  1. Saponins, especially platycodin D, from Platycodon grandiflorum modulate hepatic lipogenesis in high-fat diet-fed rats and high glucose-exposed HepG2 cells

    International Nuclear Information System (INIS)

    AMP-activated protein kinase (AMPK) plays a central role in controlling hepatic lipid metabolism through modulating the downstream acetyl CoA carboxylase (ACC) and sterol regulatory element-binding protein-1c (SREBP-1c) pathway. Saponins, particularly platycodin D, from the roots of Platycodon grandiflorum (Changkil saponins, CKS) have a variety of pharmacological properties, including antioxidant and hepatoprotective properties. The aim of this study was to investigate the effects of CKS on hepatic lipogenesis and on the expression of genes involved in lipogenesis, and the mechanisms involved. CKS attenuated fat accumulation and the induction of the lipogenic genes encoding SREBP-1c and fatty acid synthase in the livers of HFD-fed rats and in steatotic HepG2 cells. Blood biochemical analyses and histopathological examinations showed that CKS prevented liver injury. CKS and platycodin D each increased the phosphorylation of AMPK and acetyl-CoA carboxylase in HFD-fed rats and HepG2 cells. The use of specific inhibitors showed that platycodin D activated AMPK via SIRT1/CaMKKβ in HepG2 cells. This study demonstrates that CKS or platycodin D alone can regulate hepatic lipogenesis via an AMPK-dependent signalling pathway. - Highlights: ► CKS attenuated fat accumulation in HFD-fed rats and in steatotic HepG2 cells. ► CKS and its major component, platycodin D, inhibited the levels of SREBP-1 and FAS. ► CKS and platycodin D increased the phosphorylation of AMPK and ACC. ► Platycodin D activated AMPK via SIRT1/CaMKKβ in HepG2 cells

  2. Saponins, especially platycodin D, from Platycodon grandiflorum modulate hepatic lipogenesis in high-fat diet-fed rats and high glucose-exposed HepG2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yong Pil [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Department of Pharmaceutical Engineering, International University of Korea, Jinju (Korea, Republic of); Choi, Jae Ho; Kim, Hyung Gyun; Khanal, Tilak; Song, Gye Young [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Nam, Myoung Soo [College of Agriculture and Life Sciences, Chungnam National University, Daejeon (Korea, Republic of); Lee, Hyun-Sun [Molecular Cancer Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Chung, Young Chul; Lee, Young Chun [Division of Food Science, International University of Korea, Jinju (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2013-03-01

    AMP-activated protein kinase (AMPK) plays a central role in controlling hepatic lipid metabolism through modulating the downstream acetyl CoA carboxylase (ACC) and sterol regulatory element-binding protein-1c (SREBP-1c) pathway. Saponins, particularly platycodin D, from the roots of Platycodon grandiflorum (Changkil saponins, CKS) have a variety of pharmacological properties, including antioxidant and hepatoprotective properties. The aim of this study was to investigate the effects of CKS on hepatic lipogenesis and on the expression of genes involved in lipogenesis, and the mechanisms involved. CKS attenuated fat accumulation and the induction of the lipogenic genes encoding SREBP-1c and fatty acid synthase in the livers of HFD-fed rats and in steatotic HepG2 cells. Blood biochemical analyses and histopathological examinations showed that CKS prevented liver injury. CKS and platycodin D each increased the phosphorylation of AMPK and acetyl-CoA carboxylase in HFD-fed rats and HepG2 cells. The use of specific inhibitors showed that platycodin D activated AMPK via SIRT1/CaMKKβ in HepG2 cells. This study demonstrates that CKS or platycodin D alone can regulate hepatic lipogenesis via an AMPK-dependent signalling pathway. - Highlights: ► CKS attenuated fat accumulation in HFD-fed rats and in steatotic HepG2 cells. ► CKS and its major component, platycodin D, inhibited the levels of SREBP-1 and FAS. ► CKS and platycodin D increased the phosphorylation of AMPK and ACC. ► Platycodin D activated AMPK via SIRT1/CaMKKβ in HepG2 cells.

  3. Uptake and expression of bacterial and cyanobacterial genes by isolated cucumber etioplasts

    International Nuclear Information System (INIS)

    The uptake and expression by plastids isolated from dark-grown cucumber cotyledons (etioplasts) of two pUC derivatives, pCS75 and pUC9-CM, respectively carrying genes for the large and small subunits of ribulose bisphosphate carboxylase/oxygenase of Anacystis nidulans or chloramphenicol acetyltransferase, is reported. Untreated etioplasts take up only 3% as much DNA as that taken up by EDTA-washed etioplasts after 2 hr of incubation with nick-translated [32P]-pCS75. The presence or absence of light does not affect DNA uptake, binding, or breakdown by etioplasts. Calcium or magnesium ions inhibit DNA uptake by 86% but enhance binding and breakdown of donor DNA by EDTA-treated etioplasts. Uncouplers that abolish membrane potential, transmembrane proton gradient, or both do not affect DNA uptake, binding, or breakdown by etioplasts. However, both DNA uptake and binding are severely inhibited by ATP. After the incubation of EDTA-treated etioplasts with pCS75, immunoprecipitation using antiserum to the small subunit of ribulose bisphosphate carboxylase/oxygenase from A. nidulans reveals the synthesis of small subunits. Treatment of etioplasts with 10 mM EDTA shows a 10-min duration to be optimal for the expression of chloramphenicol acetyltransferase encoded by pUC9-CM. A progressive increase in the expression of this enzyme is observed with an increase in the concentration of pUC9-CM in the DNA uptake medium. The plasmid-dependent incorporation of [35S] methionine by EDTA-treated organelles declines markedly during cotyledon greening in vivo

  4. Contribution of carbon fixed by Rubisco and PEPC to phloem export in the Crassulacean acid metabolism plant Kalanchoe daigremontiana.

    Science.gov (United States)

    Wild, Birgit; Wanek, Wolfgang; Postl, Wolfgang; Richter, Andreas

    2010-03-01

    Crassulacean acid metabolism (CAM) plants exhibit a complex interplay between CO(2) fixation by phosphoenolpyruvate carboxylase (PEPC) and ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), and carbon demand for CAM maintenance and growth. This study investigated the flux of carbon from PEPC and direct Rubisco fixation to different leaf carbon pools and to phloem sap over the diurnal cycle. Concentrations and carbon isotope compositions of starch, soluble sugars, and organic acids were determined in leaves and phloem exudates of Kalanchoë daigremontiana Hamet et Perr., and related to CO(2) fixation by PEPC and Rubisco. Three types of leaf carbon pools could be distinguished. (i) Starch and malate pools were dominant and showed a pattern of reciprocal mobilization and accumulation (85/54 and 13/48 mg C g(-1) DW, respective, at the beginning/end of phase I). The carbon isotope composition of these pools was compatible with predominant PEPC fixation (delta(13)C values of -13 and -11 per thousand for starch and malate compared to -11 per thousand of PEPC fixed carbon). (ii) Isotopic composition (-17 per thousand and -14 per thousand) and concentration of glucose and fructose (2 and 3 mg C g(-1) DW, respectively) were not affected by diurnal metabolism, suggesting a low turnover. (iii) Sucrose (1-3 mg C g(-1) DW), in contrast, exhibited large diurnal changes in delta(13)C values (from -17 per thousand in the evening to -12 per thousand in the morning), which were not matched by net changes in sucrose concentration. This suggests a high sucrose turnover, fed by nocturnal starch degradation and direct Rubisco fixation during the day. A detailed dissection of the carbon fixation and mobilization pattern in K. daigremontiana revealed that direct fixation of Rubisco during the light accounted for 30% of phloem sucrose, but only 15% of fixed carbon, indicating that carbon from direct Rubisco fixation was preferentially used for leaf export. PMID:20159885

  5. Systems-wide metabolic pathway engineering in Corynebacterium glutamicum for bio-based production of diaminopentane.

    Science.gov (United States)

    Kind, Stefanie; Jeong, Weol Kyu; Schröder, Hartwig; Wittmann, Christoph

    2010-07-01

    In the present work the Gram-positive bacterium Corynebacterium glutamicum was engineered into an efficient, tailor-made production strain for diaminopentane (cadaverine), a highly attractive building block for bio-based polyamides. The engineering comprised expression of lysine decarboxylase (ldcC) from Escherichia coli, catalyzing the conversion of lysine into diaminopentane, and systems-wide metabolic engineering of central supporting pathways. Substantially re-designing the metabolism yielded superior strains with desirable properties such as (i) the release from unwanted feedback regulation at the level of aspartokinase and pyruvate carboxylase by introducing the point mutations lysC311 and pycA458, (ii) an optimized supply of the key precursor oxaloacetate by amplifying the anaplerotic enzyme, pyruvate carboxylase, and deleting phosphoenolpyruvate carboxykinase which otherwise removes oxaloacetate, (iii) enhanced biosynthetic flux via combined amplification of aspartokinase, dihydrodipicolinate reductase, diaminopimelate dehydrogenase and diaminopimelate decarboxylase, and (iv) attenuated flux into the threonine pathway competing with production by the leaky mutation hom59 in the homoserine dehydrogenase gene. Lysine decarboxylase proved to be a bottleneck for efficient production, since its in vitro activity and in vivo flux were closely correlated. To achieve an optimal strain having only stable genomic modifications, the combination of the strong constitutive C. glutamicum tuf promoter and optimized codon usage allowed efficient genome-based ldcC expression and resulted in a high diaminopentane yield of 200 mmol mol(-1). By supplementing the medium with 1 mgL(-1) pyridoxal, the cofactor of lysine decarboxylase, the yield was increased to 300 mmol mol(-1). In the production strain obtained, lysine secretion was almost completely abolished. Metabolic analysis, however, revealed substantial formation of an as yet unknown by-product. It was identified as an

  6. Study on roles of anaplerotic pathways in glutamate overproduction of Corynebacterium glutamicum by metabolic flux analysis

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    Shioya Suteaki

    2007-06-01

    Full Text Available Abstract Background Corynebacterium glutamicum has several anaplerotic pathways (anaplerosis, which are essential for the productions of amino acids, such as lysine and glutamate. It is still not clear how flux changes in anaplerotic pathways happen when glutamate production is induced by triggers, such as biotin depletion and the addition of the detergent material, Tween 40. In this study, we quantitatively analyzed which anaplerotic pathway flux most markedly changes the glutamate overproduction induced by Tween 40 addition. Results We performed a metabolic flux analysis (MFA with [1-13C]- and [U-13C]-labeled glucose in the glutamate production phase of C. glutamicum, based on the analysis of the time courses of 13C incorporation into proteinogenic amino acids by gas chromatography-mass spectrometry (GC-MS. The flux from phosphoenolpyruvate (PEP to oxaloacetate (Oxa catalyzed by phosphoenolpyruvate carboxylase (PEPc was active in the growth phase not producing glutamate, whereas that from pyruvate to Oxa catalyzed by pyruvate carboxylase (Pc was inactive. In the glutamate overproduction phase induced by the addition of the detergent material Tween 40, the reaction catalyzed by Pc also became active in addition to the reaction catalyzed by PEPc. Conclusion It was clarified by a quantitative 13C MFA that the reaction catalyzed by Pc is most markedly increased, whereas other fluxes of PEPc and PEPck remain constant in the glutamate overproduction induced by Tween 40. This result is consistent with the previous results obtained in a comparative study on the glutamate productions of genetically recombinant Pc- and PEPc-overexpressing strains. The importance of a specific reaction in an anaplerotic pathway was elucidated at a metabolic level by MFA.

  7. Characterization of the biotin uptake system encoded by the biotin-inducible bioYMN operon of Corynebacterium glutamicum

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    Schneider Jens

    2012-01-01

    Full Text Available Abstract Background The amino acid-producing Gram-positive Corynebacterium glutamicum is auxotrophic for biotin although biotin ring assembly starting from the precursor pimeloyl-CoA is still functional. It possesses AccBC, the α-subunit of the acyl-carboxylases involved in fatty acid and mycolic acid synthesis, and pyruvate carboxylase as the only biotin-containing proteins. Comparative genome analyses suggested that the putative transport system BioYMN encoded by cg2147, cg2148 and cg2149 might be involved in biotin uptake by C. glutamicum. Results By comparison of global gene expression patterns of cells grown with limiting or excess supply of biotin or with dethiobiotin as supplement replacing biotin revealed that expression of genes coding for enzymes of biotin ring assembly and for the putative uptake system was regulated according to biotin availability. RT-PCR and 5'-RACE experiments demonstrated that the genes bioY, bioM, and bioN are transcribed from one promoter as a single transcript. Biochemical analyses revealed that BioYMN catalyzes the effective uptake of biotin with a concentration of 60 nM biotin supporting a half-maximal transport rate. Maximal biotin uptake rates were at least five fold higher in biotin-limited cells as compared to cells grown with excess biotin. Overexpression of bioYMN led to an at least 50 fold higher biotin uptake rate as compared to the empty vector control. Overproduction of BioYMN alleviated biotin limitation and interfered with triggering L-glutamate production by biotin limitation. Conclusions The operon bioYMN from C. glutamicum was shown to be induced by biotin limitation. Transport assays with radio-labeled biotin revealed that BioYMN functions as a biotin uptake system. Overexpression of bioYMN affected L-glutamate production triggered by biotin limitation.

  8. C4 Photosynthetic Gene Expression in Light- and Dark-Grown Amaranth Cotyledons.

    Science.gov (United States)

    Wang, J. L.; Long, J. J.; Hotchkiss, T.; Berry, J. O.

    1993-08-01

    The patterns of expression for genes encoding several C4 photosynthetic enzymes were examined in light-grown and dark-grown (etiolated) cotyledons of amaranth (Amaranthus hypochondriacus), a dicotyledonous C4 plant. The large subunit and small subunit of ribulose-1,5-bisphosphate carboxylase (RuBPCase), phosphoenolpyruvate carboxylase (PEPCase), and pyruvate orthophosphate dikinase (PPdK) were all present in the cotyledons by d 2 after planting when the seedlings first emerged from the seed coat. Kranz anatomy was apparent in light-grown cotyledons throughout development, and the overall patterns of C4 gene expression were similar to those recently described for developing amaranth leaves (J.L. Wang, D.F. Klessig, J.O. Berry [1992] Plant Cell 4: 173-184). RuBPCase mRNA and proteins were present in both bundle sheath and mesophyll cells in a C3-like pattern during early development and became progressively more localized to bundle sheath cells in the C4-type pattern as the cotyledons expanded over 2 to 7 d. PEPCase and PPdK polypeptides were localized to mesophyll cells throughout development, even though PEPCase transcripts were detected in both bundle sheath and mesophyll cells. Kranz anatomy also developed in cotyledons grown in complete darkness. In 7-d-old dark-grown cotyledons, RuBPCase, PPdK, and PEPCase were all localized to the appropriate cell types, although at somewhat lower levels than in light-grown cotyledons. These findings demonstrate that the leaves and postembryonic cotyledons of amaranth undergo common developmental programs of C4 gene expression during maturation. Furthermore, light is not required for the cell-type-specific expression of genes encoding RuBPCase and other photosynthetic enzymes in this dicotyledonous C4 plant. PMID:12231890

  9. Growth Properties and Biomass Production in the Hybrid C4 Crop Sorghum bicolor.

    Science.gov (United States)

    Tazoe, Youshi; Sazuka, Takashi; Yamaguchi, Miki; Saito, Chieko; Ikeuchi, Masahiro; Kanno, Keiichi; Kojima, Soichi; Hirano, Ko; Kitano, Hideki; Kasuga, Shigemitsu; Endo, Tsuyoshi; Fukuda, Hiroo; Makino, Amane

    2016-05-01

    Hybrid vigor (heterosis) has been used as a breeding technique for crop improvement to achieve enhanced biomass production, but the physiological mechanisms underlying heterosis remain poorly understood. In this study, to find a clue to the enhancement of biomass production by heterosis, we systemically evaluated the effect of heterosis on the growth rate and photosynthetic efficiency in sorghum hybrid [Sorghum bicolor (L.) Moench cv. Tentaka] and its parental lines (restorer line and maintainer line). The final biomass of Tentaka was 10-14 times greater than that of the parental lines grown in an experimental field, but the relative growth rate during the vegetative growth stage did not differ. Tentaka exhibited a relatively enlarged leaf area with lower leaf nitrogen content per leaf area (Narea). When the plants were grown hydroponically at different N levels, daily CO2 assimilation per leaf area (A) increased with Narea, and the ratio of A to Narea (N-use efficiency) was higher in the plants grown at low N levels but not different between Tentaka and the parental lines. The relationships between the CO2 assimilation rate, the amounts of photosynthetic enzymes, including ribulose-1,5-bisphosphate carboxylase/oxygenase, phosphoenolpyruvate carboxylase and pyruvate phosphate dikinase, Chl and Narea did not differ between Tentaka and the parental lines. Thus, Tentaka tended to exhibit enlargement of leaf area with lower N content, leading to a higher N-use efficiency for CO2 assimilation, but the photosynthetic properties did not differ. The greater biomass in Tentaka was mainly due to the prolonged vegetative growth period. PMID:26508521

  10. Human holocarboxylase synthetase with a start site at methionine-58 is the predominant nuclear variant of this protein and has catalytic activity

    International Nuclear Information System (INIS)

    Highlights: → Unambiguous evidence is provided that methionine-58 serves as an in-frame alternative translation site for holocarboxylase synthetase (HLCS58). → Full-length HLCS and HLCS58 enter the nucleus, but HLCS58 is the predominant variant. → HLCS58 has biological activity as biotin protein ligase. -- Abstract: Holocarboxylase synthetase (HLCS) catalyzes the covalent binding of biotin to both carboxylases in extranuclear structures and histones in cell nuclei, thereby mediating important roles in intermediary metabolism, gene regulation, and genome stability. HLCS has three putative translational start sites (methionine-1, -7, and -58), but lacks a strong nuclear localization sequence that would explain its participation in epigenetic events in the cell nucleus. Recent evidence suggests that small quantities of HLCS with a start site in methionine-58 (HLCS58) might be able to enter the nuclear compartment. We generated the following novel insights into HLCS biology. First, we generated a novel HLCS fusion protein vector to demonstrate that methionine-58 is a functional translation start site in human cells. Second, we used confocal microscopy and western blots to demonstrate that HLCS58 enters the cell nucleus in meaningful quantities, and that full-length HLCS localizes predominantly in the cytoplasm but may also enter the nucleus. Third, we produced recombinant HLCS58 to demonstrate its biological activity toward catalyzing the biotinylation of both carboxylases and histones. Collectively, these observations are consistent with roles of HLCS58 and full-length HLCS in nuclear events. We conclude this report by proposing a novel role for HLCS in epigenetic events, mediated by physical interactions between HLCS and other chromatin proteins as part of a larger multiprotein complex that mediates gene repression.

  11. Observations of the uptake of carbonyl sulfide (COS by trees under elevated atmospheric carbon dioxide concentrations

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    L. Sandoval-Soto

    2012-08-01

    Full Text Available Global change forces ecosystems to adapt to elevated atmospheric concentrations of carbon dioxide (CO2. We understand that carbonyl sulfide (COS, a trace gas which is involved in building up the stratospheric sulfate aerosol layer, is taken up by vegetation with the same triad of the enzymes which are metabolizing CO2, i.e. ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, phosphoenolpyruvate carboxylase (PEP-Co and carbonic anhydrase (CA. Therefore, we discuss a physiological/biochemical acclimation of these enzymes affecting the sink strength of vegetation for COS. We investigated the acclimation of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers under elevated CO2, and determined the exchange characteristics and the content of CA after a 1–2 yr period of acclimation from 350 ppm to 800 ppm CO2. We demonstrate that a compensation point, by definition, does not exist. Instead, we propose to discuss a point of uptake affinity (PUA. The results indicate that such a PUA, the CA activity and the deposition velocities may change and may cause a decrease of the COS uptake by plant ecosystems, at least as long as the enzyme acclimation to CO2 is not surpassed by an increase of atmospheric COS. As a consequence, the atmospheric COS level may rise causing an increase of the radiative forcing in the troposphere. However, this increase is counterbalanced by the stronger input of this trace gas into the stratosphere causing a stronger energy reflection by the stratospheric sulfur aerosol into space (Brühl et al., 2012. These data are very preliminary but may trigger a discussion on COS uptake acclimation to foster measurements with modern analytical instruments.

  12. Comparative physiological and biochemical investigations of spruce trees damaged by immissions in context with forest decline in the Northern Black Forest. Vergleichende physiologische und biochemische Untersuchungen an immissionsgeschaedigten Fichten im Zusammenhang mit den neuartigen Waldschaeden an einem Standort im Nordschwarzwald

    Energy Technology Data Exchange (ETDEWEB)

    Wild, A.; Forschner, W. (Mainz Univ. (Germany, F.R.). Inst. fuer Allgemeine Botanik)

    1990-04-01

    The structural and functional state of the thylakoid membranes is investigated by measuring photosynthetic electron transport, Q{sub B}-protein, P-700, cytochrome f, and chlorophyl a+b content. Investigations of the content of ascorbic acid and glutathione, the activity of catalase, and the content of phenoles are carried out in order to demonstrate activation of the protective mechanisms against photooxidative processes. Further metabolic changes will be diagnosed by the investigation of nitrogen metabolism (protein content, glutamine-synthetase, glutamate-dehydrogenase, amino acids, polyamines, NH{sub 4}{sup +}, total nitrogen content). In order to indicate general stress and water stress, the activity of phosphoenolpyruvate-carboxylase, malate content, proline content, and osmotic potential are determined. By means of fluorescence microscopic investigation, dead cells of the mesophyll can be identified. In comparison to the apparently healthy trees, the damaged spruce trees showed a decrease in the electron transport rate, chlorophyll a+b content, and Q{sub B}-protein content. The contents of ascorbic acid, glutathione, phenoles, as well as the activity of catalase, increased in damaged trees. The parameters of the nitrogen metabolism indicated a catabolism of proteins. The protein content decreased, the amine acid content showed an increase. This is due to the advanced damage of the trees, which is recognizable in a great number of dead cells in the mesophyll. Furthermore, stress conditions are indicated by an increase in the activity of the phosphoenolpyruvate-carboxylase, the content of malate and proline, as well as the decrease of the osmotic potential. (orig.).

  13. Photosynthetic carbon metabolism in photoautotrophic cell suspension cultures grown at low and high CO2

    International Nuclear Information System (INIS)

    Photosynthetic carbon metabolism was characterized in four photoautotrophic cell suspension cultures. There was no apparent difference between two soybeans (Glycine max) and one cotton (Gossypium hirsutum) cell line which required 5% CO2 for growth, and a unique cotton cell line that grows at ambient CO2 (660 microliters per liter). Photosynthetic characteristics in all four lines were more like C3 mesophyll leaf cells than the cell suspension cultures previously studied. The pattern of 14C-labeling reflected the high ratio of ribulosebisphosphate carboxylase to phosphoenolpyruvate carboxylase activity and showed that CO2 fixation occurred primarily by the C3 pathway. Photorespiration occurred at 330 microliters per liter CO2, 21% O2 as indicated by the synthesis of high levels of 14C-labeled glycine and serine in a pulse-chase experiment and by oxygen inhibition of CO2 fixation. Short-term CO2 fixation in the presence and absence of carbonic anhydrase showed CO2, not HCO3-, to be the main source of inorganic carbon taken up by the low CO2-requiring cotton cells. The cells did not have a CO2-concentrating mechanism as indicated by silicone oil centrifugation experiments. Carbonic anhydrase was absent in the low CO2-requiring cotton cells, present in the high CO2-requiring soybean cell lines, and absent in other high CO2 cell lines examined. Thus, the presence of carbonic anhydrase is not an essential requirement for photoautotrophy in cell suspension cultures which grow at either high or low CO2 concentrations

  14. Stereochemical determination of carbon partitioning between photosynthesis and photorespiration in C3 plants: use of (3R)-D-[3-3H1, 3-14C]glyceric acid

    International Nuclear Information System (INIS)

    When (3R)-D-[3-3H1,3-14C]glyceric acid is supplied in tracer amounts to illuminated tobacco leaf discs, the acid penetrates to the chloroplasts without loss of 3H, and is phosphorylated there. Subsequent metabolism associated with the reductive photosynthetic cycle fully conserves 3H. Oxidation of ribulose bisphosphate (RuBP) by RuBP carboxylase-oxygenase (EC 4.1.1.39) results in the formation of (2R)-[2-3H1, 14C]glycolic acid which, on oxidation by glycolate oxidase (EC 1.1.3.1), releases 3H to water. Loss of 3H from the combined photosynthetic and photorespiratory systems is, therefore, associated with the oxidative photorespiratory loop. Assuming steady-state conditions and a basic metabolic model, the fraction of RuBP oxidized and the photorespiratory carbon flux relative to gross or net CO2 fixation can be calculated from the fraction of supplied 3H retained in the triose phosphates exported from the chloroplasts. This retention can be determined from the 3H:14C ratio for glucose obtained from isolated sucrose. The dependence of 3H retention upon O2 and CO2 concentrations can be deduced by assuming simple competitive kinetics for RuBP carboxylase-oxygenase. The experimental results confirmed the stereochemical assumptions made. Under conditions of negligible photorespiration 3H retention was essentially complete. The change in 3H retention with O2 and CO2 concentrations were investigated. For leaf discs (upper surface up) in normal air, it was estimated that 39% of the RuBP was oxidized, 32% of the fixed CO2 was photorespired, and the photorespiration rate was 46% of the net photosynthetic CO2 fixation rate. These are minimal estimates, as it is assumed that the only source of photorespired CO2 is glycine decarboxylation

  15. The genome sequence of Propionibacterium acidipropionici provides insights into its biotechnological and industrial potential

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    Parizzi Lucas P

    2012-10-01

    Full Text Available Abstract Background Synthetic biology allows the development of new biochemical pathways for the production of chemicals from renewable sources. One major challenge is the identification of suitable microorganisms to hold these pathways with sufficient robustness and high yield. In this work we analyzed the genome of the propionic acid producer Actinobacteria Propionibacterium acidipropionici (ATCC 4875. Results The assembled P. acidipropionici genome has 3,656,170 base pairs (bp with 68.8% G + C content and a low-copy plasmid of 6,868 bp. We identified 3,336 protein coding genes, approximately 1000 more than P. freudenreichii and P. acnes, with an increase in the number of genes putatively involved in maintenance of genome integrity, as well as the presence of an invertase and genes putatively involved in carbon catabolite repression. In addition, we made an experimental confirmation of the ability of P. acidipropionici to fix CO2, but no phosphoenolpyruvate carboxylase coding gene was found in the genome. Instead, we identified the pyruvate carboxylase gene and confirmed the presence of the corresponding enzyme in proteome analysis as a potential candidate for this activity. Similarly, the phosphate acetyltransferase and acetate kinase genes, which are considered responsible for acetate formation, were not present in the genome. In P. acidipropionici, a similar function seems to be performed by an ADP forming acetate-CoA ligase gene and its corresponding enzyme was confirmed in the proteome analysis. Conclusions Our data shows that P. acidipropionici has several of the desired features that are required to become a platform for the production of chemical commodities: multiple pathways for efficient feedstock utilization, ability to fix CO2, robustness, and efficient production of propionic acid, a potential precursor for valuable 3-carbon compounds.

  16. A first insight into the occurrence and expression of functional amoA and accA genes of autotrophic and ammonia-oxidizing bathypelagic Crenarchaeota of Tyrrhenian Sea

    Science.gov (United States)

    Yakimov, Michail M.; Cono, Violetta La; Denaro, Renata

    2009-05-01

    The autotrophic and ammonia-oxidizing crenarchaeal assemblage at offshore site located in the deep Mediterranean (Tyrrhenian Sea, depth 3000 m) water was studied by PCR amplification of the key functional genes involved in energy (ammonia mono-oxygenase alpha subunit, amoA) and central metabolism (acetyl-CoA carboxylase alpha subunit, accA). Using two recently annotated genomes of marine crenarchaeons, an initial set of primers targeting archaeal accA-like genes was designed. Approximately 300 clones were analyzed, of which 100% of amoA library and almost 70% of accA library were unambiguously related to the corresponding genes from marine Crenarchaeota. Even though the acetyl-CoA carboxylase is phylogenetically not well conserved and the remaining clones were affiliated to various bacterial acetyl-CoA/propionyl-CoA carboxylase genes, the pool of archaeal sequences was applied for development of quantitative PCR analysis of accA-like distribution using TaqMan ® methodolgy. The archaeal accA gene fragments, together with alignable gene fragments from the Sargasso Sea and North Pacific Subtropical Gyre (ALOHA Station) metagenome databases, were analyzed by multiple sequence alignment. Two accA-like sequences, found in ALOHA Station at the depth of 4000 m, formed a deeply branched clade with 64% of all archaeal Tyrrhenian clones. No close relatives for residual 36% of clones, except of those recovered from Eastern Mediterranean, was found, suggesting the existence of a specific lineage of the crenarchaeal accA genes in deep Mediterranean water. Alignment of Mediterranean amoA sequences defined four cosmopolitan phylotypes of Crenarchaeota putative ammonia mono-oxygenase subunit A gene occurring in the water sample from the 3000 m depth. Without exception all phylotypes fell into Deep Marine Group I cluster that contain the vast majority of known sequences recovered from global deep-sea environment. Remarkably, three phylotypes accounted for 91% of all Mediterranean

  17. MR spectroscopy-based brain metabolite profiling in propionic acidaemia: metabolic changes in the basal ganglia during acute decompensation and effect of liver transplantation

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    McKiernan Patrick J

    2011-05-01

    Full Text Available Abstract Background Propionic acidaemia (PA results from deficiency of Propionyl CoA carboxylase, the commonest form presenting in the neonatal period. Despite best current management, PA is associated with severe neurological sequelae, in particular movement disorders resulting from basal ganglia infarction, although the pathogenesis remains poorly understood. The role of liver transplantation remains controversial but may confer some neuro-protection. The present study utilises quantitative magnetic resonance spectroscopy (MRS to investigate brain metabolite alterations in propionic acidaemia during metabolic stability and acute encephalopathic episodes. Methods Quantitative MRS was used to evaluate brain metabolites in eight children with neonatal onset propionic acidaemia, with six elective studies acquired during metabolic stability and five studies during acute encephalopathic episodes. MRS studies were acquired concurrently with clinically indicated MR imaging studies at 1.5 Tesla. LCModel software was used to provide metabolite quantification. Comparison was made with a dataset of MRS metabolite concentrations from a cohort of children with normal appearing MR imaging. Results MRI findings confirm the vulnerability of basal ganglia to infarction during acute encephalopathy. We identified statistically significant decreases in basal ganglia glutamate+glutamine and N-Acetylaspartate, and increase in lactate, during encephalopathic episodes. In white matter lactate was significantly elevated but other metabolites not significantly altered. Metabolite data from two children who had received liver transplantation were not significantly different from the comparator group. Conclusions The metabolite alterations seen in propionic acidaemia in the basal ganglia during acute encephalopathy reflect loss of viable neurons, and a switch to anaerobic respiration. The decrease in glutamine + glutamate supports the hypothesis that they are consumed to

  18. Effects of dry period length and dietary energy source on metabolic status and hepatic gene expression of dairy cows in early lactation.

    Science.gov (United States)

    Chen, J; Gross, J J; van Dorland, H A; Remmelink, G J; Bruckmaier, R M; Kemp, B; van Knegsel, A T M

    2015-02-01

    In a prior study, we observed that cows with a 0-d dry period had greater energy balance and lower milk production compared with cows with a 30- or 60-d dry period in early lactation. The objective of the current study was to evaluate the influence of dry period length on metabolic status and hepatic gene expression in cows fed a lipogenic or glucogenic diet in early lactation. Holstein-Friesian dairy cows (n=167) were assigned randomly to 3×2 factorial design with 3 dry period lengths (n=56, 55, and 56 for 0-, 30-, and 60-d dry, respectively) and 2 early lactation diets (n=84 and 83 for glucogenic and lipogenic diet, respectively). Cows were fed a glucogenic or lipogenic diet from 10d before the expected calving date and onward. The main ingredient for a glucogenic concentrate was corn, and the main ingredients for a lipogenic concentrate were sugar beet pulp, palm kernel, and rumen-protected palm oil. Blood was sampled weekly from 95 cows from wk 3 precalving to wk 8 postcalving. Liver samples were collected from 76 cows in wk -2, 2, and 4 relative to calving. Liver samples were analyzed for triacylglycerol concentrations and mRNA expression of 12 candidate genes. Precalving, cows with a 0-d dry period had greater plasma β-hydroxybutyrate, urea, and insulin concentrations compared with cows with a 30- or 60-d dry period. Postcalving, cows with a 0-d dry period had lower liver triacylglycerol and plasma nonesterified fatty acids concentrations (0.20, 0.32, and 0.36mmol/L for 0-, 30-, and 60-d dry period, respectively), greater plasma glucose, insulin-like growth factor-I, and insulin (24.38, 14.02, and 11.08µIU/mL for 0-, 30-, and 60-d dry period, respectively) concentrations, and lower hepatic mRNA expression of pyruvate carboxylase, compared with cows with a 30- or 60-d dry period. Plasma urea and β-hydroxybutyrate concentrations were greater in cows fed a lipogenic diet compared with cows fed a glucogenic diet. In conclusion, cows with a 0-d dry period had

  19. Air pollutant exclusion experiment with spruce trees at Edelmannshof. Physiological and biochemical investigations

    Energy Technology Data Exchange (ETDEWEB)

    Bittlingmaier, L. [comp.

    1997-12-01

    Morphologic, physiological and biochemical parameters determined with spruce trees under ambient and OTC conditions at the Edelmannshof site were as follows: fine root density and degree of mycorrhization, needle anatomy, xylem sap flow, stomatal conductance, leaf gas exchange, parameters of photosynthetic electron transport, energy, nitrogen and carbohydrate metabolism, levels of antioxidants, {Delta}{sup 13}C, phosphoenolpyruvate carboxylase (PEPC), and phytohormones. Owing to the rather low levels of ambient pollutants, and considerable physiological differences between individual trees, decline symptoms did not develop to such an extent that they became apparent for all parameters tested. The few data indicating differences at least between the chamber trees (filtered versus ambient air, compare also statistical analysis) such as gas exchange, carboxylation efficiency, content of pigments (chlorophylls, cytochromes), PEPC, or the adenylate ratio, show that these parameters obviously are sensitive enough to detect pollutant (ozone) effects without the manifestation of visible symptoms. Thus, the data from the Edelmannshof experiment are very valuable as they give an idea about the flexibility of leaf metabolism of spruce under low to medium loads of pollutants such as ozone. Seperate entries are prepared. 13 of them are taken to be considered.(orig.) [Deutsch] An Fichten unter Freiland- und OTC-Bedingungen (Edelmannshof) wurden die folgenden morphologischen, physiologischen und biochemischen Parameter bestimmt: Feinwurzeldichte und Grad der Mykorrhizierung, Nadelanatomie, Saftfluss im Xylem, stomataere Leitfaehigkeit, Gaswechsel der Nadeln, Parameter des photosynthetischen Elektronentransports, Energie-Stickstoff- und Kohlenhydratstoffwechsel, Gehalte an Antioxidatien, {Delta}{sup 13}C, Phosphoenolpyruvat Carboxylase (PEPC) und Phytohormone. Aufgrund der relativ geringen Eintraege an Luftschadstoffen und der deutlichen physiologischen Unterschiede zwischen den

  20. Metabolic responses to pyruvate kinase deletion in lysine producing Corynebacterium glutamicum

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    Wittmann Christoph

    2008-03-01

    Full Text Available Abstract Background Pyruvate kinase is an important element in flux control of the intermediate metabolism. It catalyzes the irreversible conversion of phosphoenolpyruvate into pyruvate and is under allosteric control. In Corynebacterium glutamicum, this enzyme was regarded as promising target for improved production of lysine, one of the major amino acids in animal nutrition. In pyruvate kinase deficient strains the required equimolar ratio of the two lysine precursors oxaloacetate and pyruvate can be achieved through concerted action of the phosphotransferase system (PTS and phosphoenolpyruvate carboxylase (PEPC, whereby a reduced amount of carbon may be lost as CO2 due to reduced flux into the tricarboxylic acid (TCA cycle. In previous studies, deletion of pyruvate kinase in lysine-producing C. glutamicum, however, did not yield a clear picture and the exact metabolic consequences are not fully understood. Results In this work, deletion of the pyk gene, encoding pyruvate kinase, was carried out in the lysine-producing strain C. glutamicum lysCfbr, expressing a feedback resistant aspartokinase, to investigate the cellular response to deletion of this central glycolytic enzyme. Pyk deletion was achieved by allelic replacement, verified by PCR analysis and the lack of in vitro enzyme activity. The deletion mutant showed an overall growth behavior (specific growth rate, glucose uptake rate, biomass yield which was very similar to that of the parent strain, but differed in slightly reduced lysine formation, increased formation of the overflow metabolites dihydroxyacetone and glycerol and in metabolic fluxes around the pyruvate node. The latter involved a flux shift from pyruvate carboxylase (PC to PEPC, by which the cell maintained anaplerotic supply of the TCA cycle. This created a metabolic by-pass from PEP to pyruvate via malic enzyme demonstrating its contribution to metabolic flexibility of C. glutamicum on glucose. Conclusion The metabolic