Base de dados : MEDLINE
Pesquisa : B01.268.250.320 [Categoria DeCS]
Referências encontradas : 620 [refinar]
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  1 / 620 MEDLINE  
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[PMID]:28452248
[Au] Autor:Milisa M; Dikic D; Mandic T; Grozic D; Colic I; Ostojic A
[Ad] Endereço:a Department of Biology, Faculty of Science , University of Zagreb , Zagreb , Croatia.
[Ti] Título:Response of aquatic protists to electric field exposure.
[So] Source:Int J Radiat Biol;93(8):818-830, 2017 08.
[Is] ISSN:1362-3095
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:PURPOSE: To test the effects of short-term exposure of aquatic organisms to electric field (EF) with negligible magnetic component. MATERIALS AND METHODS: We built a plate capacitor that served as a source of EF of strengths that can be found in nature near transmission lines. We exposed two cultured protist species Euglena viridis and Paramecium caudatum to EFs for 24 hours and monitored their abundance, morphology, intracellular superoxide anion (by dihydroethidium [DHE]), hydrogen peroxide by (H DCF) and lipid peroxidation (MDA) contents, catalase (CAT) and superoxide dismutase (SOD) activity. RESULTS: We found that even short-term exposure to low strength EF causes changes in population abundance, morphology and oxidative stress response in both species. As the EF strength increased, abundance of both species decreased. However, at weaker EFs, fission rates were seemingly promoted. We noted a decrease in size in both organisms in directions perpendicular to their fission planes correlated with EF strength. DHE and H DCF fluorescence intensity and SOD activity were higher in organisms exposed to the stronger EFs. CONCLUSIONS: We suggest that the electric component of the field, rather than the magnetic, is the main cause of all the noted effects. As a result, aquatic organisms should be given greater importance in studies assessing the effects of EMFs in spite of the attenuating effects of water to EF strengths.
[Mh] Termos MeSH primário: Eletricidade
Euglena/metabolismo
Paramecium caudatum/metabolismo
[Mh] Termos MeSH secundário: Catalase/metabolismo
Membrana Celular/metabolismo
Peróxido de Hidrogênio/metabolismo
Espaço Intracelular/metabolismo
L-Lactato Desidrogenase/metabolismo
Peroxidação de Lipídeos
Malondialdeído/metabolismo
Superóxido Dismutase/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
4Y8F71G49Q (Malondialdehyde); BBX060AN9V (Hydrogen Peroxide); EC 1.1.1.27 (L-Lactate Dehydrogenase); EC 1.11.1.6 (Catalase); EC 1.15.1.1 (Superoxide Dismutase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:180111
[Lr] Data última revisão:
180111
[Sb] Subgrupo de revista:IM; S
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.1080/09553002.2017.1321809


  2 / 620 MEDLINE  
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[PMID]:28429326
[Au] Autor:Inui H; Ishikawa T; Tamoi M
[Ad] Endereço:Department of Nutrition, Osaka Prefecture University, 30-7-3 Habikino, Habikino, Osaka, 583-8555, Japan. inui@biochem.osakafu-u.ac.jp.
[Ti] Título:Wax Ester Fermentation and Its Application for Biofuel Production.
[So] Source:Adv Exp Med Biol;979:269-283, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In Euglena cells under anaerobic conditions, paramylon, the storage polysaccharide, is promptly degraded and converted to wax esters. The wax esters synthesized are composed of saturated fatty acids and alcohols with chain lengths of 10-18, and the major constituents are myristic acid and myristyl alcohol. Since the anaerobic cells gain ATP through the conversion of paramylon to wax esters, the phenomenon is named "wax ester fermentation". The wax ester fermentation is quite unique in that the end products, i.e. wax esters, have relatively high molecular weights, are insoluble in water, and accumulate in the cells, in contrast to the common fermentation end products such as lactic acid and ethanol.A unique metabolic pathway involved in the wax ester fermentation is the mitochondrial fatty acid synthetic system. In this system, fatty acid are synthesized by the reversal of ß-oxidation with an exception that trans-2-enoyl-CoA reductase functions instead of acyl-CoA dehydrogenase. Therefore, acetyl-CoA is directly used as a C donor in this fatty acid synthesis, and the conversion of acetyl-CoA to malonyl-CoA, which requires ATP, is not necessary. Consequently, the mitochondrial fatty acid synthetic system makes possible the net gain of ATP through the synthesis of wax esters from paramylon. In addition, acetyl-CoA is provided in the anaerobic cells from pyruvate by the action of a unique enzyme, oxygen sensitive pyruvate:NADP oxidoreductase, instead of the common pyruvate dehydrogenase multienzyme complex.Wax esters produced by anaerobic Euglena are promising biofuels because myristic acid (C ) in contrast to other algal produced fatty acids, such as palmitic acid (C ) and stearic acid (C ), has a low freezing point making it suitable as a drop-in jet fuel. To improve wax ester production, the molecular mechanisms by which wax ester fermentation is regulated in response to aerobic and anaerobic conditions have been gradually elucidated by identifying individual genes related to the wax ester fermentation metabolic pathway and by comprehensive gene/protein expression analysis. In addition, expression of the cyanobacterial Calvin cycle fructose-1,6-bisphosphatase/sedohepturose-1,7-bisphosphatase, in Euglena provided photosynthesis resulting in increased paramylon accumulation enhancing wax ester production. This chapter will discuss the biochemistry of the wax ester fermentation, recent advances in our understanding of the regulation of the wax ester fermentation and genetic engineering approaches to increase production of wax esters for biofuels.
[Mh] Termos MeSH primário: Biocombustíveis
Euglena/metabolismo
Ácidos Graxos/metabolismo
Álcoois Graxos/metabolismo
Proteínas de Protozoários/metabolismo
[Mh] Termos MeSH secundário: Anaerobiose/fisiologia
Euglena/genética
Proteínas de Protozoários/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Biofuels); 0 (Fatty Acids); 0 (Fatty Alcohols); 0 (Protozoan Proteins)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_13


  3 / 620 MEDLINE  
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[PMID]:28429325
[Au] Autor:Häder DP; Hemmersbach R
[Ad] Endereço:Department of Biology, Friedrich-Alexander Universität, Erlangen-Nürnberg, Neue Str. 9, 91096, Möhrendorf, Germany. donat@dphaeder.de.
[Ti] Título:Gravitaxis in Euglena.
[So] Source:Adv Exp Med Biol;979:237-266, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Motile microorganisms utilize a number of responses to external stimuli including light, temperature, chemicals as well as magnetic and electric fields. Gravity is a major clue to select a niche in their environment. Positive gravitaxis leads an organism down into the water column and negative gravitaxis brings it to the surface. In Euglena the precision of gravitaxis is regulated by an internal rhythm entrained by the daily light/dark cycle. This and the cooperation with phototaxis bring the cells into an optimal position in the water column. In the past a passive orientation based on a buoy mechanism has been proposed for Euglena gracilis, but now it has been proven that this flagellate possesses a physiological gravireceptor and an active orientation. Numerous experiments in space using satellites, rockets and shuttles as well as in parabolic flights have been conducted as well as in functional weightlessness (simulated microgravity) on ground-based facilities such as clinostats to characterize the gravitaxis of Euglena. The threshold for gravity perception was determined and physiological, biochemical and molecular components of the signal transduction chain have been identified. In contrast to higher plants, some algae and ciliates, Euglena does not possess sedimenting statoliths to detect the direction of the gravity vector of the Earth. The gravireceptors were found to be mechano-sensitive Ca -conducting ion channels thought to be located at the front end of the cell underneath the trailing flagellum. When activated by gravity-induced pressure due to sedimentation of the whole cell body, they allow a passive influx of calcium along a previously established ion gradient. The entering calcium binds to a specific calmodulin (CaM.2) which in turn activates an adenylyl cyclase producing cAMP from ATP. This cAMP is believed to activate a specific protein kinase A (PK.4), which is postulated to phosphorylate proteins inside the flagellum resulting in a bending and thus a course correction and reorientation with respect to the direction of the gravity vector. The elements of the signal transduction chain have been characterized by inhibitors and by RNAi to prove their involvement in gravitaxis.
[Mh] Termos MeSH primário: Sinalização do Cálcio/fisiologia
Euglena/fisiologia
Flagelos/metabolismo
Gravitação
Proteínas de Protozoários/metabolismo
Resposta Táctica/fisiologia
[Mh] Termos MeSH secundário: Flagelos/genética
Proteínas de Protozoários/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Nm] Nome de substância:
0 (Protozoan Proteins)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_12


  4 / 620 MEDLINE  
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[PMID]:28429323
[Au] Autor:Durnford DG; Schwartzbach SD
[Ad] Endereço:Department of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, NB, Canada, E3B 5A3.
[Ti] Título:Protein Targeting to the Plastid of Euglena.
[So] Source:Adv Exp Med Biol;979:183-205, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The lateral transfer of photosynthesis between kingdoms through endosymbiosis is among the most spectacular examples of evolutionary innovation. Euglena, which acquired a chloroplast indirectly through an endosymbiosis with a green alga, represents such an example. As with other endosymbiont-derived plastids from eukaryotes, there are additional membranes that surround the organelle, of which Euglena has three. Thus, photosynthetic genes that were transferred from the endosymbiont to the host nucleus and whose proteins are required in the new plastid, are now faced with targeting and plastid import challenges. Early immunoelectron microscopy data suggested that the light-harvesting complexes, photosynthetic proteins in the thylakoid membrane, are post-translationally targeted to the plastid via the Golgi apparatus, an unexpected discovery at the time. Proteins targeted to the Euglena plastid have complex, bipartite presequences that direct them into the endomembrane system, through the Golgi apparatus and ultimately on to the plastid, presumably via transport vesicles. From transcriptome sequencing, dozens of plastid-targeted proteins were identified, leading to the identification of two different presequence structures. Both have an amino terminal signal peptide followed by a transit peptide for plastid import, but only one of the two classes of presequences has a third domain-the stop transfer sequence. This discovery implied two different transport mechanisms; one where the protein was fully inserted into the lumen of the ER and another where the protein remains attached to, but effectively outside, the endomembrane system. In this review, we will discuss the biochemical and bioinformatic evidence for plastid targeting, discuss the evolution of the targeting system, and ultimately provide a working model for the targeting and import of proteins into the plastid of Euglena.
[Mh] Termos MeSH primário: Euglena/fisiologia
Complexo de Golgi/fisiologia
Membranas Intracelulares/fisiologia
Proteínas de Protozoários/metabolismo
Tilacoides/fisiologia
[Mh] Termos MeSH secundário: Euglena/ultraestrutura
Complexo de Golgi/ultraestrutura
Membranas Intracelulares/ultraestrutura
Transporte Proteico/fisiologia
Proteínas de Protozoários/genética
Tilacoides/ultraestrutura
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Protozoan Proteins)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_10


  5 / 620 MEDLINE  
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[PMID]:28429322
[Au] Autor:Schwartzbach SD
[Ad] Endereço:Department of Biological Sciences, University of Memphis, Memphis, TN, 38152, USA. sdschwrt@memphis.edu.
[Ti] Título:Photo and Nutritional Regulation of Euglena Organelle Development.
[So] Source:Adv Exp Med Biol;979:159-182, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Euglena can use light and CO , photosynthesis, as well as a large variety of organic molecules as the sole source of carbon and energy for growth. Light induces the enzymes, in this case an entire organelle, the chloroplast, that is required to use CO as the sole source of carbon and energy for growth. Ethanol, but not malate, inhibits the photoinduction of chloroplast enzymes and induces the synthesis of the glyoxylate cycle enzymes that comprise the unique metabolic pathway leading to two carbon, ethanol and acetate, assimilation. In resting, carbon starved cells, light mobilizes the degradation of the storage carbohydrate paramylum and transiently induces the mitochondrial proteins required for the aerobic metabolism of paramylum to provide the carbon and energy required for chloroplast development. Other mitochondrial proteins are degraded upon light exposure providing the amino acids required for the synthesis of light induced proteins. Changes in protein levels are due to increased and decreased rates of synthesis rather than changes in degradation rates. Changes in protein synthesis rates occur in the absence of a concomitant increase in the levels of mRNAs encoding these proteins indicative of photo and metabolic control at the translational rather than the transcriptional level. The fraction of mRNA encoding a light induced protein such as the light harvesting chlorophyll a/b binding protein of photosystem II, (LHCPII) associated with polysomes in the dark is similar to the fraction associated with polysomes in the light indicative of photoregulation at the level of translational elongation. Ethanol, a carbon source whose assimilation requires carbon source specific enzymes, the glyoxylate cycle enzymes, represses the synthesis of chloroplast enzymes uniquely required to use light and CO as the sole source of carbon and energy for growth. The catabolite sensitivity of chloroplast development provides a mechanism to prioritize carbon source utilization. Euglena uses all of its resources to develop the metabolic capacity to utilize carbon sources such as ethanol which are rarely in the environment and delays until the rare carbon source is no longer available forming the chloroplast which is required to utilize the ubiquitous carbon source, light and CO .
[Mh] Termos MeSH primário: Cloroplastos/fisiologia
Euglena/fisiologia
Mitocôndrias/fisiologia
Consumo de Oxigênio/fisiologia
Fotossíntese/fisiologia
[Mh] Termos MeSH secundário: Proteínas de Cloroplastos/genética
Proteínas de Cloroplastos/metabolismo
Proteínas Mitocondriais/genética
Proteínas Mitocondriais/metabolismo
Proteínas de Protozoários/genética
Proteínas de Protozoários/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Chloroplast Proteins); 0 (Mitochondrial Proteins); 0 (Protozoan Proteins)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_9


  6 / 620 MEDLINE  
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[PMID]:28429321
[Au] Autor:McWatters DC; Russell AG
[Ad] Endereço:Department of Biological Sciences, University of Lethbridge, 4401 University Dr W, Lethbridge, AB, Canada, T1K 6T5.
[Ti] Título:Euglena Transcript Processing.
[So] Source:Adv Exp Med Biol;979:141-158, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:RNA transcript processing is an important stage in the gene expression pathway of all organisms and is subject to various mechanisms of control that influence the final levels of gene products. RNA processing involves events such as nuclease-mediated cleavage, removal of intervening sequences referred to as introns and modifications to RNA structure (nucleoside modification and editing). In Euglena, RNA transcript processing was initially examined in chloroplasts because of historical interest in the secondary endosymbiotic origin of this organelle in this organism. More recent efforts to examine mitochondrial genome structure and RNA maturation have been stimulated by the discovery of unusual processing pathways in other Euglenozoans such as kinetoplastids and diplonemids. Eukaryotes containing large genomes are now known to typically contain large collections of introns and regulatory RNAs involved in RNA processing events, and Euglena gracilis in particular has a relatively large genome for a protist. Studies examining the structure of nuclear genes and the mechanisms involved in nuclear RNA processing have revealed that indeed Euglena contains large numbers of introns in the limited set of genes so far examined and also possesses large numbers of specific classes of regulatory and processing RNAs, such as small nucleolar RNAs (snoRNAs). Most interestingly, these studies have also revealed that Euglena possesses novel processing pathways generating highly fragmented cytosolic ribosomal RNAs and subunits and non-conventional intron classes removed by unknown splicing mechanisms. This unexpected diversity in RNA processing pathways emphasizes the importance of identifying the components involved in these processing mechanisms and their evolutionary emergence in Euglena species.
[Mh] Termos MeSH primário: Euglena/fisiologia
Genoma de Protozoário/fisiologia
Processamento Pós-Transcricional do RNA/fisiologia
RNA de Protozoário/metabolismo
[Mh] Termos MeSH secundário: Euglena/classificação
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
RNA de Protozoário/genética
RNA Ribossômico/genética
RNA Ribossômico/metabolismo
RNA Nucleolar Pequeno/genética
RNA Nucleolar Pequeno/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (RNA, Messenger); 0 (RNA, Protozoan); 0 (RNA, Ribosomal); 0 (RNA, Small Nucleolar)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_8


  7 / 620 MEDLINE  
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[PMID]:28429319
[Au] Autor:Moreno-Sánchez R; Rodríguez-Enríquez S; Jasso-Chávez R; Saavedra E; García-García JD
[Ad] Endereço:Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, Ciudad de México, 14080, México. rafael.moreno@cardiologia.org.mx.
[Ti] Título:Biochemistry and Physiology of Heavy Metal Resistance and Accumulation in Euglena.
[So] Source:Adv Exp Med Biol;979:91-121, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Free-living microorganisms may become suitable models for removal of heavy metals from polluted water bodies, sediments, and soils by using and enhancing their metal accumulating abilities. The available research data indicate that protists of the genus Euglena are a highly promising group of microorganisms to be used in bio-remediation of heavy metal-polluted aerobic and anaerobic acidic aquatic environments. This chapter analyzes the variety of biochemical mechanisms evolved in E. gracilis to resist, accumulate and remove heavy metals from the environment, being the most relevant those involving (1) adsorption to the external cell pellicle; (2) intracellular binding by glutathione and glutathione polymers, and their further compartmentalization as heavy metal-complexes into chloroplasts and mitochondria; (3) polyphosphate biosynthesis; and (4) secretion of organic acids. The available data at the transcriptional, kinetic and metabolic levels on these metabolic/cellular processes are herein reviewed and analyzed to provide mechanistic basis for developing genetically engineered Euglena cells that may have a greater removal and accumulating capacity for bioremediation and recycling of heavy metals.
[Mh] Termos MeSH primário: Resistência a Medicamentos/fisiologia
Euglena/fisiologia
Metais Pesados/metabolismo
[Mh] Termos MeSH secundário: Biodegradação Ambiental
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Nm] Nome de substância:
0 (Metals, Heavy)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_6


  8 / 620 MEDLINE  
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[PMID]:28429318
[Au] Autor:Watanabe F; Yoshimura K; Shigeoka S
[Ad] Endereço:Faculty of Agriculture, School of Agricultural, Biological and Environmental Sciences, Tottori University, Tottori, 680-8553, Japan. watanabe@muses.tottori-u.ac.jp.
[Ti] Título:Biochemistry and Physiology of Vitamins in Euglena.
[So] Source:Adv Exp Med Biol;979:65-90, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Euglena gracilis Z requires vitamins B1 and B12 for growth. It takes up and accumulates large amounts of these exogenous vitamins through energy-dependent active transport systems. Except for these essential vitamins, E. gracilis Z has the ability to synthesize all human vitamins. Euglena synthesizes high levels of antioxidant vitamins such as vitamins C and E, and, thus, are used as nutritional supplements for humans and domestic animals. Methods to effectively produce vitamins in Euglena have been investigated.Previous biochemical studies indicated that E. gracilis Z contains several vitamin-related novel synthetic enzymes and metabolic pathways which suggests that it is a highly suitable organism for elucidating the physiological functions of vitamins in comparative biochemistry and biological evolution. E. gracilis Z has an unusual biosynthetic pathway for vitamin C, a hybrid of the pathways found in animals and plants. This chapter presents up-to-date information on the biochemistry and physiological functions of vitamins in this organism.
[Mh] Termos MeSH primário: Ácido Ascórbico/biossíntese
Euglena/fisiologia
Tiamina/biossíntese
Vitamina B 12/biossíntese
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
P6YC3EG204 (Vitamin B 12); PQ6CK8PD0R (Ascorbic Acid); X66NSO3N35 (Thiamine)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_5


  9 / 620 MEDLINE  
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[PMID]:28429317
[Au] Autor:Ishikawa T; Tamaki S; Maruta T; Shigeoka S
[Ad] Endereço:Faculty of Life and Environmental Science, Shimane University, 1060 Nishikawatsu, Matsue, Shimane, 690-8504, Japan. ishikawa@life.shimane-u.ac.jp.
[Ti] Título:Biochemistry and Physiology of Reactive Oxygen Species in Euglena.
[So] Source:Adv Exp Med Biol;979:47-64, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Reactive oxygen species (ROS) such as superoxide and hydrogen peroxide are by-products of various metabolic processes in aerobic organisms including Euglena. Chloroplasts and mitochondria are the main sites of ROS generation by photosynthesis and respiration, respectively, through the active electron transport chain. An efficient antioxidant network is required to maintain intracellular ROS pools at optimal conditions for redox homeostasis. A comparison with the networks of plants and animals revealed that Euglena has acquired some aspects of ROS metabolic process. Euglena lacks catalase and a typical selenocysteine containing animal-type glutathione peroxidase for hydrogen peroxide scavenging, but contains enzymes involved in ascorbate-glutathione cycle solely in the cytosol. Ascorbate peroxidase in Euglena, which plays a central role in the ascorbate-glutathione cycle, forms a unique intra-molecular dimer structure that is related to the recognition of peroxides. We recently identified peroxiredoxin and NADPH-dependent thioredoxin reductase isoforms in cellular compartments including chloroplasts and mitochondria, indicating the physiological significance of the thioredoxin system in metabolism of ROS. Besides glutathione, Euglena contains the unusual thiol compound trypanothione, an unusual form of glutathione involving two molecules of glutathione joined by a spermidine linker, which has been identified in pathogenic protists such as Trypanosomatida and Schizopyrenida. Furthermore, in contrast to plants, photosynthesis by Euglena is not susceptible to hydrogen peroxide because of resistance of the Calvin cycle enzymes fructose-1,6-bisphosphatse, NADP -glyceraldehyde-3-phosphatase, sedoheptulose-1,7-bisphosphatase, and phosphoribulokinase to hydrogen peroxide. Consequently, these characteristics of Euglena appear to exemplify a strategy for survival and adaptation to various environmental conditions during the evolutionary process of euglenoids.
[Mh] Termos MeSH primário: Cloroplastos/metabolismo
Euglena/fisiologia
Mitocôndrias/metabolismo
Consumo de Oxigênio/fisiologia
Fotossíntese/fisiologia
Espécies Reativas de Oxigênio/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Reactive Oxygen Species)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_4


  10 / 620 MEDLINE  
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[PMID]:28429316
[Au] Autor:Nakazawa M
[Ad] Endereço:Faculty of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka, Japan. mami@biochem.osakafu-u.ac.jp.
[Ti] Título:C2 metabolism in Euglena.
[So] Source:Adv Exp Med Biol;979:39-45, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Euglenoids are able to assimilate fatty acids and alcohols with various carbon-chain lengths, and ethanol is known to be one of the best carbon sources to support the growth of Euglena gracilis. Ethanol is first oxidized to acetate by the sequential reactions of alcohol dehydrogenase and acetaldehyde dehydrogenase in the mitochondria, and then converted to acetyl coenzyme A (acetyl-CoA). Acetyl-CoA is metabolized through the glyoxylate cycle which is a modified tricarboxylic acid (TCA) cycle in which isocitrate lyase (ICL) and malate synthase (MS) function to bypass the two decarboxylation steps of the TCA cycle, enabling the net synthesis of carbohydrates from C2 compounds. ICL and MS form a unique bifunctional enzyme localized in Euglena mitochondria, not in glyoxysome as in other eukaryotes. The unique glyoxylate and glycolate metabolism during photorespiration is also discussed in this chapter.
[Mh] Termos MeSH primário: Ácido Acético/metabolismo
Etanol/metabolismo
Euglena/metabolismo
Glicolatos/metabolismo
Glioxilatos/metabolismo
[Mh] Termos MeSH secundário: Ciclo do Ácido Cítrico/fisiologia
Mitocôndrias/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Glycolates); 0 (Glyoxylates); 0WT12SX38S (glycolic acid); 3K9958V90M (Ethanol); JQ39C92HH6 (glyoxylic acid); Q40Q9N063P (Acetic Acid)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-54910-1_3



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