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Pesquisa : G02.111.248 [Categoria DeCS]
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  1 / 23916 MEDLINE  
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[PMID]:29066393
[Au] Autor:Badshah SL; Sun J; Mula S; Gorka M; Baker P; Luthra R; Lin S; van der Est A; Golbeck JH; Redding KE
[Ad] Endereço:School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
[Ti] Título:Mutations in algal and cyanobacterial Photosystem I that independently affect the yield of initial charge separation in the two electron transfer cofactor branches.
[So] Source:Biochim Biophys Acta;1859(1):42-55, 2018 01.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:In Photosystem I, light-induced electron transfer can occur in either of two symmetry-related branches of cofactors, each of which is composed of a pair of chlorophylls (ec2 /ec3 or ec2 /ec3 ) and a phylloquinone (PhQ or PhQ ). The axial ligand to the central Mg of the ec2 and ec2 chlorophylls is a water molecule that is also H-bonded to a nearby Asn residue. Here, we investigate the importance of this interaction for charge separation by converting each of the Asn residues to a Leu in the green alga, Chlamydomonas reinhardtii, and the cyanobacterium, Synechocystis sp. PCC6803, and studying the energy and electron transfer using time-resolved optical and EPR spectroscopy. Nanosecond transient absorbance measurements of the PhQ to F electron transfer show that in both species, the PsaA-N604L mutation (near ec2 ) results in a ~50% reduction in the amount of electron transfer in the B-branch, while the PsaB-N591L mutation (near ec2 ) results in a ~70% reduction in the amount of electron transfer in the A-branch. A diminished quantum yield of P PhQ is also observed in ultrafast optical experiments, but the lower yield does not appear to be a consequence of charge recombination in the nanosecond or microsecond timescales. The most significant finding is that the yield of electron transfer in the unaffected branch did not increase to compensate for the lower yield in the affected branch. Hence, each branch of the reaction center appears to operate independently of the other in carrying out light-induced charge separation.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Chlamydomonas reinhardtii/enzimologia
Mutação de Sentido Incorreto
Complexo de Proteína do Fotossistema I/química
Complexo de Proteína do Fotossistema I/genética
Synechocystis/enzimologia
[Mh] Termos MeSH secundário: Substituição de Aminoácidos
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Chlamydomonas reinhardtii/genética
Transporte de Elétrons
Complexo de Proteína do Fotossistema I/metabolismo
Synechocystis/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Photosystem I Protein Complex)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171026
[St] Status:MEDLINE


  2 / 23916 MEDLINE  
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[PMID]:28986298
[Au] Autor:Hsiao JC; McGrath AP; Kielmann L; Kalimuthu P; Darain F; Bernhardt PV; Harmer J; Lee M; Meyers K; Maher MJ; Kappler U
[Ad] Endereço:Centre for Metals in Biology, School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD 4072, Australia.
[Ti] Título:The central active site arginine in sulfite oxidizing enzymes alters kinetic properties by controlling electron transfer and redox interactions.
[So] Source:Biochim Biophys Acta;1859(1):19-27, 2018 01.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:A central conserved arginine, first identified as a clinical mutation leading to sulfite oxidase deficiency, is essential for catalytic competency of sulfite oxidizing molybdoenzymes, but the molecular basis for its effects on turnover and substrate affinity have not been fully elucidated. We have used a bacterial sulfite dehydrogenase, SorT, which lacks an internal heme group, but transfers electrons to an external, electron accepting cytochrome, SorU, to investigate the molecular functions of this arginine residue (Arg78). Assay of the SorT Mo centre catalytic competency in the absence of SorU showed that substitutions in the central arginine (R78Q, R78K and R78M mutations) only moderately altered SorT catalytic properties, except for R78M which caused significant reduction in SorT activity. The substitutions also altered the Mo-centre redox potentials (Mo potential lowered by ca. 60-80mV). However, all Arg78 mutations significantly impaired the ability of SorT to transfer electrons to SorU, where activities were reduced 17 to 46-fold compared to SorT , precluding determination of kinetic parameters. This was accompanied by the observation of conformational changes in both the introduced Gln and Lys residues in the crystal structure of the enzymes. Taking into account data collected by others on related SOE mutations we propose that the formation and maintenance of an electron transfer complex between the Mo centre and electron accepting heme groups is the main function of the central arginine, and that the reduced turnover and increases in K are caused by the inefficient operation of the oxidative half reaction of the catalytic cycle in enzymes carrying these mutations.
[Mh] Termos MeSH primário: Arginina/química
Proteínas de Bactérias/química
Sinorhizobium meliloti/enzimologia
Sulfito Desidrogenase/química
[Mh] Termos MeSH secundário: Substituição de Aminoácidos
Arginina/metabolismo
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Domínio Catalítico
Transporte de Elétrons
Cinética
Molibdênio
Mutação de Sentido Incorreto
Oxirredução
Sinorhizobium meliloti/genética
Sulfito Desidrogenase/genética
Sulfito Desidrogenase/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 81AH48963U (Molybdenum); 94ZLA3W45F (Arginine); EC 1.8.2.1 (Sulfite Dehydrogenase)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171008
[St] Status:MEDLINE


  3 / 23916 MEDLINE  
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[PMID]:29351332
[Au] Autor:Grebenko A; Dremov V; Barzilovich P; Bubis A; Sidoruk K; Voeikova T; Gagkaeva Z; Chernov T; Korostylev E; Gorshunov B; Motovilov K
[Ad] Endereço:Moscow Institute of Physics and Technology, Institute lane 9, Dolgoprudny, Russian Federation.
[Ti] Título:Impedance spectroscopy of single bacterial nanofilament reveals water-mediated charge transfer.
[So] Source:PLoS One;13(1):e0191289, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:For decades respiratory chain and photosystems were the main firing field of the studies devoted to mechanisms of electron transfer in proteins. The concept of conjugated lateral electron and transverse proton transport during cellular respiration and photosynthesis, which was formulated in the beginning of 1960-s, has been confirmed by thousands of experiments. However, charge transfer in recently discovered bacterial nanofilaments produced by various electrogenic bacteria is regarded currently outside of electron and proton conjugation concept. Here we report the new study of charge transfer within nanofilaments produced by Shewanella oneidensis MR-1 conducted in atmosphere of different relative humidity (RH). We utilize impedance spectroscopy and DC (direct current) transport measurements to find out the peculiarities of conductivity and Raman spectroscopy to analyze the nanofilaments' composition. Data analysis demonstrates that apparent conductivity of nanofilaments has crucial sensitivity to humidity and contains several components including one with unusual behavior which we assign to electron transport. We demonstrate that in the case of Shewanella oneidensis MR-1 charge transfer within these objects is strongly mediated by water. Basing on current data analysis of conductivity we conclude that the studied filaments of Shewanella oneidensis MR-1 are capable of hybrid (conjugated) electron and ion conductivity.
[Mh] Termos MeSH primário: Shewanella/metabolismo
Água/metabolismo
[Mh] Termos MeSH secundário: Citocromos/química
Citocromos/metabolismo
Espectroscopia Dielétrica
Transporte de Elétrons
Heme/metabolismo
Umidade
Shewanella/citologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cytochromes); 059QF0KO0R (Water); 42VZT0U6YR (Heme)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180226
[Lr] Data última revisão:
180226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180120
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0191289


  4 / 23916 MEDLINE  
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[PMID]:29203277
[Au] Autor:Escrivá L; Jennen D; Caiment F; Manyes L
[Ad] Endereço:Laboratory of Food Chemistry and Toxicology, Faculty of Pharmacy, University of Valencia, Burjassot, Spain. Electronic address: laura.escriva@uv.es.
[Ti] Título:Transcriptomic study of the toxic mechanism triggered by beauvericin in Jurkat cells.
[So] Source:Toxicol Lett;284:213-221, 2018 Mar 01.
[Is] ISSN:1879-3169
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Beauvericin (BEA), an ionophoric cyclic hexadepsipeptide mycotoxin, is able to increase oxidative stress by altering membrane ion permeability and uncoupling oxidative phosphorylation. A toxicogenomic study was performed to investigate gene expression changes triggered by BEA exposure (1.5, 3 and 5 µM; 24 h) in Jurkat cells through RNA-sequencing and differential gene expression analysis. Perturbed gene expression was observed in a concentration dependent manner, with 43 differentially expressed genes (DEGs) overlapped in the three studied concentrations. Gene ontology (GO) analysis showed several biological processes related to electron transport chain, oxidative phosphorylation, and cellular respiration significantly altered. Molecular functions linked to mitochondrial respiratory chain and oxidoreductase activity were over-represented (q-value < 0.01). Pathway analysis revealed oxidative phosphorylation and electron transport chain as the most significantly altered pathways in all studied doses (z-score > 1.96; adj p-value < 0.05). 77 genes involved in the respiratory chain were significantly down-regulated at least at one dose. Moreover, 21 genes related to apoptosis and programmed cell death, and 12 genes related to caspase activity were significantly altered, mainly affecting initiator caspases 8, 9 and 10. The results demonstrated BEA-induced mitochondrial damage affecting the respiratory chain, and pointing to apoptosis through the caspase cascade in human lymphoblastic T cells.
[Mh] Termos MeSH primário: Apoptose/efeitos dos fármacos
Depsipeptídeos/toxicidade
Estresse Oxidativo/efeitos dos fármacos
Transcriptoma/efeitos dos fármacos
[Mh] Termos MeSH secundário: Apoptose/genética
Técnicas de Cultura de Células
Permeabilidade da Membrana Celular/efeitos dos fármacos
Permeabilidade da Membrana Celular/genética
Relação Dose-Resposta a Droga
Transporte de Elétrons
Perfilação da Expressão Gênica
Ontologia Genética
Seres Humanos
Células Jurkat
Fosforilação Oxidativa
Estresse Oxidativo/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Depsipeptides); 26S048LS2R (beauvericin)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180221
[Lr] Data última revisão:
180221
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171206
[St] Status:MEDLINE


  5 / 23916 MEDLINE  
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[PMID]:29298981
[Au] Autor:Díaz MG; Hernández-Verdeja T; Kremnev D; Crawford T; Dubreuil C; Strand Å
[Ad] Endereço:Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, SE-901 87, Umeå, Sweden.
[Ti] Título:Redox regulation of PEP activity during seedling establishment in Arabidopsis thaliana.
[So] Source:Nat Commun;9(1):50, 2018 01 03.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Activation of the plastid-encoded RNA polymerase is tightly controlled and involves a network of phosphorylation and, as yet unidentified, thiol-mediated events. Here, we characterize PLASTID REDOX INSENSITIVE2, a redox-regulated protein required for full PEP-driven transcription. PRIN2 dimers can be reduced into the active monomeric form by thioredoxins through reduction of a disulfide bond. Exposure to light increases the ratio between the monomeric and dimeric forms of PRIN2. Complementation of prin2-2 with different PRIN2 protein variants demonstrates that the monomer is required for light-activated PEP-dependent transcription and that expression of the nuclear-encoded photosynthesis genes is linked to the activity of PEP. Activation of PEP during chloroplast development likely is the source of a retrograde signal that promotes nuclear LHCB expression. Thus, regulation of PRIN2 is the thiol-mediated mechanism required for full PEP activity, with PRIN2 monomerization via reduction by TRXs providing a mechanistic link between photosynthetic electron transport and activation of photosynthetic gene expression.
[Mh] Termos MeSH primário: Proteínas de Arabidopsis/metabolismo
Arabidopsis/enzimologia
Tiorredoxinas de Cloroplastos/metabolismo
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
Plântulas/enzimologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Transporte de Elétrons
Fotossíntese
Plastídeos/metabolismo
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Arabidopsis Proteins); 0 (Chloroplast Thioredoxins); 0 (Intracellular Signaling Peptides and Proteins); 0 (PRIN2 protein, Arabidopsis); 0 (thioredoxin z, Arabidopsis)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180215
[Lr] Data última revisão:
180215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180105
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02468-2


  6 / 23916 MEDLINE  
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[PMID]:29217137
[Au] Autor:Broniarek I; Jarmuszkiewicz W
[Ad] Endereço:Department of Bioenergetics, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University in Poznan, Poland.
[Ti] Título:Atorvastatin affects negatively respiratory function of isolated endothelial mitochondria.
[So] Source:Arch Biochem Biophys;637:64-72, 2018 01 01.
[Is] ISSN:1096-0384
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The purpose of this research was to elucidate the direct effects of two popular blood cholesterol-lowering drugs used to treat cardiovascular diseases, atorvastatin and pravastatin, on respiratory function, membrane potential, and reactive oxygen species formation in mitochondria isolated from human umbilical vein endothelial cells (EA.hy926 cell line). Hydrophilic pravastatin did not significantly affect endothelial mitochondria function. In contrast, hydrophobic calcium-containing atorvastatin induced a loss of outer mitochondrial membrane integrity, an increase in hydrogen peroxide formation, and reductions in maximal (phosphorylating or uncoupled) respiratory rate, membrane potential and oxidative phosphorylation efficiency. The atorvastatin-induced changes indicate an impairment of mitochondrial function at the level of ATP synthesis and at the level of the respiratory chain, likely at complex I and complex III. The atorvastatin action on endothelial mitochondria was highly dependent on calcium ions and led to a disturbance in mitochondrial calcium homeostasis. Uptake of calcium ions included in atorvastatin molecule induced mitochondrial uncoupling that enhanced the inhibition of the mitochondrial respiratory chain by atorvastatin. Our results indicate that hydrophobic calcium-containing atorvastatin, widely used as anti-atherosclerotic agent, has a direct negative action on isolated endothelial mitochondria.
[Mh] Termos MeSH primário: Atorvastatina Cálcica/toxicidade
Inibidores de Hidroximetilglutaril-CoA Redutases/toxicidade
Mitocôndrias/efeitos dos fármacos
Mitocôndrias/metabolismo
Respiração/efeitos dos fármacos
[Mh] Termos MeSH secundário: Cálcio/metabolismo
Transporte de Elétrons/efeitos dos fármacos
Células Endoteliais da Veia Umbilical Humana
Seres Humanos
Potencial da Membrana Mitocondrial/efeitos dos fármacos
Membranas Mitocondriais/efeitos dos fármacos
Membranas Mitocondriais/metabolismo
Fosforilação Oxidativa/efeitos dos fármacos
Consumo de Oxigênio/efeitos dos fármacos
Pravastatina/toxicidade
Espécies Reativas de Oxigênio/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Hydroxymethylglutaryl-CoA Reductase Inhibitors); 0 (Reactive Oxygen Species); 48A5M73Z4Q (Atorvastatin Calcium); KXO2KT9N0G (Pravastatin); SY7Q814VUP (Calcium)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180212
[Lr] Data última revisão:
180212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171209
[St] Status:MEDLINE


  7 / 23916 MEDLINE  
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[PMID]:29361219
[Au] Autor:Agostini A; Palm DM; Paulsen H; Carbonera D
[Ad] Endereço:Department of Chemical Sciences, University of Padova , Via Marzolo 1, 35131 Padova, Italy.
[Ti] Título:Accessibility of Protein-Bound Chlorophylls Probed by Dynamic Electron Polarization.
[So] Source:J Phys Chem Lett;9(3):672-676, 2018 Feb 01.
[Is] ISSN:1948-7185
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The possibility to probe the accessibility of sites of proteins represents an important point to explore their interactions with specific substrates in solution. The dynamic electron polarization of nitroxide radicals induced by excited triplet states of organic molecules is a phenomenon that is known to occur in aqueous solutions. The interaction within the radical-triplet pair causes a net emissive dynamic electron polarization of the nitroxide radical, that can be detected by means of time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy. We have exploited this effect to prove the accessibility of chlorophylls bound to a protein, namely, the water-soluble chlorophyll protein WSCP. The results have important implications for topological studies in macromolecules.
[Mh] Termos MeSH primário: Clorofila/química
Óxidos de Nitrogênio/química
Proteínas/química
[Mh] Termos MeSH secundário: Espectroscopia de Ressonância de Spin Eletrônica
Transporte de Elétrons
Radicais Livres
Ligação Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Free Radicals); 0 (Nitrogen Oxides); 0 (Proteins); 1406-65-1 (Chlorophyll); GFQ4MMS07W (nitroxyl)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180207
[Lr] Data última revisão:
180207
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180124
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jpclett.7b03428


  8 / 23916 MEDLINE  
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[PMID]:28456637
[Au] Autor:Vienne JC; Cimetta C; Dubois M; Duburcq T; Favory R; Dessein AF; Fontaine M; Joncquel-Chevalier Curt M; Cuisset JM; Douillard C; Mention-Mulliez K; Dobbelaere D; Vamecq J
[Ad] Endereço:Department of Biochemistry and Molecular Biology, Laboratory of Hormonology, Metabolism-Nutrition & Oncology (HMNO), Center of Biology and Pathology (CBP) Pierre-Marie Degand, CHRU Lille, France.
[Ti] Título:A fast method for high resolution oxymetry study of skeletal muscle mitochondrial respiratory chain complexes.
[So] Source:Anal Biochem;528:57-62, 2017 07 01.
[Is] ISSN:1096-0309
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:High resolution oxymetry study (HROS) of skeletal muscle usually requires 90-120 min preparative phase (dissection, permeabilization and washing). This work reports on the suitability of a rapid muscle preparation which by-passes this long preparation. For a few seconds only, muscle biopsy from pigs is submitted to gentle homogenization at 8000 rotations per minute using an ultra-dispersor apparatus. Subsequent HROS is performed using FCCP instead of ADP, compounds crossing and not plasma membrane, respectively. This simplified procedure compares favorably with classical (permeabilized fibers) HROS in terms of respiratory chain complex activities. Mitochondria from cells undergoing ultradispersion were functionally preserved as attested by relative inefficacy of added cytochrome C (not crossing intact mitochondrial outer membrane) to stimulate mitochondrial respiration. Responsiveness of respiration to ADP (in the absence of FCCP) suggested that these intact mitochondria were outside cells disrupted by ultradispersion or within cells permeated by this procedure.
[Mh] Termos MeSH primário: Respiração Celular
Mitocôndrias Musculares/metabolismo
Músculo Esquelético/metabolismo
Consumo de Oxigênio
[Mh] Termos MeSH secundário: Animais
Biópsia
Transporte de Elétrons
Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo
Feminino
Membranas Mitocondriais/metabolismo
Fibras Musculares Esqueléticas/metabolismo
Permeabilidade
Suínos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Electron Transport Chain Complex Proteins)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:180207
[Lr] Data última revisão:
180207
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170501
[St] Status:MEDLINE


  9 / 23916 MEDLINE  
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[PMID]:28450394
[Au] Autor:Korge P; John SA; Calmettes G; Weiss JN
[Ad] Endereço:From the UCLA Cardiovascular Research Laboratory and the Departments of Medicine (Cardiology) and Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095.
[Ti] Título:Reactive oxygen species production induced by pore opening in cardiac mitochondria: The role of complex II.
[So] Source:J Biol Chem;292(24):9896-9905, 2017 06 16.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Succinate-driven reverse electron transport (RET) through complex I is hypothesized to be a major source of reactive oxygen species (ROS) that induces permeability transition pore (PTP) opening and damages the heart during ischemia/reperfusion. Because RET can only generate ROS when mitochondria are fully polarized, this mechanism is self-limiting once PTP opens during reperfusion. In the accompanying article (Korge, P., Calmettes, G., John, S. A., and Weiss, J. N. (2017) 292, 9882-9895), we showed that ROS production after PTP opening can be sustained when complex III is damaged (simulated by antimycin). Here we show that complex II can also contribute to sustained ROS production in isolated rabbit cardiac mitochondria following inner membrane pore formation induced by either alamethicin or calcium-induced PTP opening. Two conditions are required to maximize malonate-sensitive ROS production by complex II in isolated mitochondria: ( ) complex II inhibition by atpenin A5 or complex III inhibition by stigmatellin that results in succinate-dependent reduction of the dicarboxylate-binding site of complex II (site II ); ( ) pore opening in the inner membrane resulting in rapid efflux of succinate/fumarate and other dicarboxylates capable of competitively binding to site II The decrease in matrix [dicarboxylate] allows O access to reduced site II , thereby making electron donation to O possible, explaining the rapid increase in ROS production provided that site II is reduced. Because ischemia is known to inhibit complexes II and III and increase matrix succinate/fumarate levels, we hypothesize that by allowing dicarboxylate efflux from the matrix, PTP opening during reperfusion may activate sustained ROS production by this mechanism after RET-driven ROS production has ceased.
[Mh] Termos MeSH primário: Complexo II de Transporte de Elétrons/metabolismo
Mitocôndrias Cardíacas/metabolismo
Modelos Moleculares
Espécies Reativas de Oxigênio/agonistas
[Mh] Termos MeSH secundário: Alameticina/farmacologia
Animais
Sítios de Ligação
Ligação Competitiva
Biocatálise/efeitos dos fármacos
Sinalização do Cálcio/efeitos dos fármacos
Transporte de Elétrons/efeitos dos fármacos
Complexo II de Transporte de Elétrons/antagonistas & inibidores
Complexo II de Transporte de Elétrons/química
Inibidores Enzimáticos/farmacologia
Fumaratos/metabolismo
Ionóforos/farmacologia
Potencial da Membrana Mitocondrial/efeitos dos fármacos
Mitocôndrias Cardíacas/química
Mitocôndrias Cardíacas/efeitos dos fármacos
Oxirredução
Permeabilidade/efeitos dos fármacos
Polienos/farmacologia
Porosidade
Piridonas/farmacologia
Coelhos
Espécies Reativas de Oxigênio/metabolismo
Ácido Succínico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Fumarates); 0 (Ionophores); 0 (Polyenes); 0 (Pyridones); 0 (Reactive Oxygen Species); 119509-24-9 (atpenin A5); 27061-78-5 (Alamethicin); 91682-96-1 (stigmatellin); AB6MNQ6J6L (Succinic Acid); EC 1.3.5.1 (Electron Transport Complex II)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:180205
[Lr] Data última revisão:
180205
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M116.768325


  10 / 23916 MEDLINE  
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[PMID]:27771433
[Au] Autor:Wilson A; Yakovlev VA
[Ad] Endereço:Department of Radiation Oncology, Massey Cancer Center, Virginia Commonwealth University, 401 College Street, Richmond, VA 23298, United States.
[Ti] Título:Cells redox environment modulates BRCA1 expression and DNA homologous recombination repair.
[So] Source:Free Radic Biol Med;101:190-201, 2016 12.
[Is] ISSN:1873-4596
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cancer development and progression have been linked to oxidative stress, a condition characterized by unbalanced increase in ROS and RNS production. The main endogenous initiators of the redox imbalance in cancer cells are defective mitochondria, elevated NOX activity, and uncoupled NOS3. Traditionally, most attention has been paid to direct oxidative damage to DNA by certain ROS. However, increase in oxidative DNA lesions does not always lead to malignancy. Hence, additional ROS-dependent, pro-carcinogenic mechanisms must be important. Our recent study demonstrated that Tyr nitration of PP2A stimulates its activity and leads to downregulation of BRCA1 expression. This provides a mechanism for chromosomal instability essential for tumor progression. In the present work, we demonstrated that inhibition of ROS production by generating mitochondrial-electron-transport-deficient cell lines (ρ cells) or by inhibition of NOX activity with a selective peptide inhibitor significantly reduced PP2A Tyr nitration and its activity in different cancer cell lines. As a result of the decreased PP2A activity, BRCA1 expression was restored along with a significantly enhanced level of DNA HRR. We used TCGA database to analyze the correlation between expressions of the NOX regulatory subunits, NOS isoforms, and BRCA1 in the 3 cancer research studies: breast invasive carcinoma, ovarian cystadenocarcinoma, and lung adenocarcinoma. TCGA database analysis demonstrated that the high expression levels of most of the NOX regulatory subunits responsible for stimulation of NOX1-NOX4 were associated with significant downregulation of BRCA1 expression.
[Mh] Termos MeSH primário: Regulação Neoplásica da Expressão Gênica
NADPH Oxidase 1/genética
Óxido Nítrico Sintase Tipo III/genética
Fosfoproteínas Fosfatases/genética
Reparo de DNA por Recombinação
Ubiquitina-Proteína Ligases/genética
[Mh] Termos MeSH secundário: Células A549
Adenocarcinoma/genética
Adenocarcinoma/metabolismo
Adenocarcinoma/patologia
Neoplasias da Mama/genética
Neoplasias da Mama/metabolismo
Neoplasias da Mama/patologia
Carcinoma Ductal de Mama/genética
Carcinoma Ductal de Mama/metabolismo
Carcinoma Ductal de Mama/patologia
Instabilidade Cromossômica
Cistadenocarcinoma Seroso/genética
Cistadenocarcinoma Seroso/metabolismo
Cistadenocarcinoma Seroso/patologia
Bases de Dados Genéticas
Transporte de Elétrons
Feminino
Seres Humanos
Isoenzimas/genética
Isoenzimas/metabolismo
Neoplasias Pulmonares/genética
Neoplasias Pulmonares/metabolismo
Neoplasias Pulmonares/patologia
Células MCF-7
Mitocôndrias/metabolismo
Mitocôndrias/patologia
NADPH Oxidase 1/metabolismo
Óxido Nítrico Sintase Tipo III/metabolismo
Neoplasias Ovarianas/genética
Neoplasias Ovarianas/metabolismo
Neoplasias Ovarianas/patologia
Oxirredução
Estresse Oxidativo
Fosfoproteínas Fosfatases/metabolismo
Espécies Reativas de Oxigênio/metabolismo
Transdução de Sinais
Ubiquitina-Proteína Ligases/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Isoenzymes); 0 (Reactive Oxygen Species); EC 1.14.13.39 (NOS3 protein, human); EC 1.14.13.39 (Nitric Oxide Synthase Type III); EC 1.6.3.- (NADPH Oxidase 1); EC 1.6.3.- (NOX1 protein, human); EC 2.3.2.27 (BRAP protein, human); EC 2.3.2.27 (Ubiquitin-Protein Ligases); EC 3.1.3.16 (Phosphoprotein Phosphatases)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:180131
[Lr] Data última revisão:
180131
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161105
[St] Status:MEDLINE



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