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redox control of magnetosome biomineralization

Journal of Oceanology and Limnology 2021年第6期39卷 2070-2081页

作者： Yingjie LI State Key Laboratory of Microbial Technology Shandong UniversityQingdao 266237China

Magnetotactic bacteria can orientate in the Earth’s magnetic field to search for their preferred microoxic environments,which is achieved by their unique organelles,the *** contain nanometer-sized crystal particles of magnetic iron minerals,which are only synthesized in lowoxygen *** the mechanism of aerobic repression for magnetosome biomineralization has not yet fully understood,a series of studies have verified that redox modulation is pivotal for magnetosome *** this review,these advances in redox modulation for magnetosome biosynthesis are highlighted,mainly including respiration pathway enzymes,specific magnetosome-associated redox proteins,and oxygen-or nitrate-sensing ***,their relationship during magnetosome biomineralization is discussed to give insight into redox control and biomineralization and inspire potential solutions for the application of respiration pathways to improve the yields of magnetosome.

关键词： magnetotactic bacteria magnetosome biomineralization respiration redox control

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Pyridine Nucleotide Cycling and control of Intracellular redox State in Relation to Poly （ADP-Ribose） Polymerase Activity and Nuclear Localization of Glutathione during Exponential Growth of Arabidopsis Cells in Culture

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Molecular Plant 2009年第3期2卷 442-456页

作者： Till K. Pellny Vittoria Locato Pedro Diaz Vivancos Jelena Markovic Laura De Gara Federico V. Pallardo Christine H. Foyer Plant Sciences Rothamsted Research Harpenden Hefts AL5 2 JQ UK CIR UniversitA Campus Bio-Medico V. A. Del Portillo 21 00128 Roma Italy School of Agriculture Food and Rural Development Newcastle University Newcastle upon Tyne NE1 7RU UK Depto. de Fisiologia Av. Blasco Ibanez 15 46010 Valencia Spain Dipartimento di Biologia e Patologia Vegetale M E. Orabona 4 70125 Bari Italy

Pyridine nucleotides, ascorbate and glutathione are major redox metabolites in plant cells, with specific roles in cellular redox homeostasis and the regulation of the cell cycle. However, the regulation of these metabolite pools during exponential growth and their precise functions in the cell cycle remain to be characterized. The present analysis of the abundance of ascorbate, glutathione, and pyridine nucleotides during exponential growth of Arabidopsis cells in culture provides evidence for the differential regulation of each of these redox pools. Ascorbate was most abundant early in the growth cycle, but glutathione was low at this point. The cellular ascorbate to dehydroascorbate and reduced glutathione （GSH） to glutathione disulphide ratios were high and constant but the pyridine nucleotide pools were largely oxidized over the period of exponential growth and only became more reduced once growth had ceased. The glutathione pool increased in parallel with poly （ADP-ribose） polymerase （PARP） activities and with increases in the abundance of PARP1 and PARP2 mRNAs at a time of high cell cycle activity as indicated by transcriptome information. Marked changes in the intracellular partitioning of GSH between the cytoplasm and nucleus were observed. Extension of the exponential growth phase by dilution or changing the media led to increases in the glutathione and nicotinamide adenine dinucleotide, oxidized form （NAD）-plus-nicotinamide adenine dinucleotide, reduced form （NADH） pools and to higher NAD/NADH ratios but the nicotinamide adenine dinucleotide phosphate, oxidized form （NADP）-plus-nicotinamide adenine dinucleotide phosphate, reduced form （NADPH） pool sizes, and NAPD/NADPH ratios were much less affected. The ascorbate, glutathione, and pyridine nucleotide pools and PARP activity decreased before the exponential growth phase ended. We conclude that there are marked changes in intracellular redox state during the growth cycle but that redox homeostasis is maint

关键词： glutathione ascorbate redox control cell cycle cell signaling cell redox state.

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Classification of Sandstone-Related Uranium Deposits

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Journal of Earth Science 2022年第2期33卷 236-256页

作者： Michel Cuney Julien Mercadier Christophe Bonnetti Universitéde Lorraine GéoRessourcesCNRSCREGUNancy F54500France 2.State Key Laboratory of Nuclear Resources and EnvironmentEast China University of TechnologyNanchang 330013China

Sandstone type deposits are the most common type of uranium deposits in the world.A large variety of sub-types have been defined,based either on the morphology of the deposits(e.g.,tabular,roll front,etc),or on the sedimentological setting(e.g.,paleovalley,paleochannel,unconformity),or on tectonic or lithologic controls(e.g.,tectonolithologic,mafic dykes/sills),or still on a variety of others characteristics(phreatic oxidation type,interlayer permeable type,multi-element stratabound infiltrational,solution front limb deposit,humate type,etc.),reflecting the diversity of the characteristics of these deposits,but making it difficult to have a clear overview of these ***,uranium deposits occurring in the same sedimentological setting(e.g.,paleochannel),presenting similar morphologies(e.g.,tabular),may result from different genetic mechanisms and thus can be misleading for exploration *** aim of the present paper is to propose a new view on sandstone-related uranium deposits combining both genetic and descriptive *** dual view is indeed of primordial importance because all the critical characteristics of each deposit type,not limited to the morphology/geometry of the ore bodies and their relationships with depositional environments of the sandstone,have to be taken into account to propose a comprehensive classification of uranium *** this respect,several key ore-forming processes,like the physical-chemical characteristics of the mineralizing fluid,have to be used to integrate genetic aspects in the *** a succession of concentration steps,potentially temporally-disconnected,are involved in the genesis of some uranium mineralization,the classification here proposed will focus on the main mechanisms responsible for the formation and/or the location of ore *** objective of this paper is also to propose a robust and widely usable terminology to define and categorize sandstone uranium deposits,considering

关键词： sandstone uranium genetic classification redox control depositional environment fluids ore deposit geology

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The Role of Phosphorylation in redox Regulation of Photosynthesis Genes psaA and psbA during Photosynthetic Acclimation of Mustard

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Molecular Plant 2009年第3期2卷 416-429页

作者： Sebastian Steiner Lars Dietzel Yvonne Schroter Vidal Fey Raik Wagner Thomas Pfannschmidt Junior Research Group 'Plant acclimation to environmental changes: Protein analysis by MS' at the Institute of General Botany and Plant Physiology Department of Plant Physiology Friedrich-Schiller-University of Jena Dornburger Str. 159 07743 Jena Germany Present address: VTT Technical research Center of Finland Medical Biotechnology Turku Finland Present address: Department of Chemistry Bioenergetics University of Umea Sweden

The long-term response （LTR） to light-quality gradients improves performance and survival of plants in dense stands. It involves redox-controlled transcriptional regulation of the plastome-encoded genes psaAB （encoding the P700 apoproteins of photosystem I） and psbA （encoding the D1 protein of photosystem II） and requires the action of plastidlocalized kinases. To study the potential impact of phosphorylation events on plastid gene expression during the LTR, we analyzed mustard seedlings acclimated to light sources favoring either photosystem I or photosystem II. Primer extension analyses of psaA transcripts indicate that the redox regulation occurs at the principal bacterial promoters, suggesting that the plastid encoded RNA polymerase （PEP） is the target for redox signals. Chloroplast protein fractions containing PEP and other DNA-binding proteins were purified from mustard via heparin-Sepharose chromatography. The biochemical properties of these fractions were analyzed with special emphasis on promoter recognition and specificity, phosphorylation state, and kinase activity. The results demonstrate that the LTR involves the action of small DNA-binding proteins; three of them exhibit specific changes in the phosphorylation state. Auto-phosphorylation assays, in addition, exhibit large differences in the activity of endogenous kinase activities. Chloroplast run-on transcription experiments with the kinase inhibitor H7 and the reductant DTT indicate that phosphorylation events are essential for the mediation of redox signals toward psaA and psbA transcription initiation, but require the synergistic action of a thiol redox signal. The data support the idea that redox signals from the thylakoid membrane are linked to gene expression via phosphorylation events; however, this mediation appears to require a complex network of interacting proteins rather than a simple phosphorelay.

关键词： Light-quality acclimation redox control protein phosphorylation chloroplast transcription Sinapis alba.

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Regulation of Cytochrome P450 Enzymes by Reversible Oxidation of Thiols to Sulfenic Acids

Regulation of Cytochrome P450 Enzymes by Reversible Oxidatio...

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中国生物化学与分子生物学会第十二届全国会员代表大会暨2...

作者： F.Peter Guengerich Matthew E.Albertolle Department of Biochemistry Vanderbilt University School of Medicine

Cytochrome P450(P450) enzymes are the major catalysts involved in the metabolism of drugs,steroids,chemical carcinogens,and fat-soluble *** they are involved in >95% of oxidation/reduction reactions of *** signature spectroscopic properties and the catalytic activities are related to a conserved cysteine thiolate ligand binding to the proximal side of the heme *** found that the activity of one human P450 enzyme,P450 4 A11,was stimulated by the addition of mild reducing agents,***,and attenuated by H2 *** analyzed the enzyme and did not find disulfides but did find that the cysteine sulfur was oxidized to a sulfenic acid(-SOH),a reversible *** then found numerous drug metabolizing enzymes that contained sulfenic acids,including several mouse and human P450 s with the heme-cysteinyl sulfenic *** sulfenic acid was found in mouse and human liver and kidney samples in situ,suggesting physiological *** dynamics simulations suggest roles for specific amino acids in modulating the oxidation of the *** part of our continuing efforts in characterization of these systems in cells,we have synthesized new heavy isotope-labeled reagents with much faster kinetics than dimedone and iodoacetamide,which can be used to label sulfenic acids and disulfides,using liquid chromatography-mass *** phenomenon represents a potential new means of post-transcriptionally regulating the activities of P450 enzymes,although more in vivo evidence is in order.

关键词： Cytochrome P450 redox control sulfenic acid drug metabolism steroidogenesis heme ligands

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