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Sample records for plant mitochondria progress

  1. Sulfide detoxification in plant mitochondria.

    Science.gov (United States)

    Birke, Hannah; Hildebrandt, Tatjana M; Wirtz, Markus; Hell, Rüdiger

    2015-01-01

    In contrast to animals, which release the signal molecule sulfide in small amounts from cysteine and its derivates, phototrophic eukaryotes generate sulfide as an essential intermediate of the sulfur assimilation pathway. Additionally, iron-sulfur cluster turnover and cyanide detoxification might contribute to the release of sulfide in mitochondria. However, sulfide is a potent inhibitor of cytochrome c oxidase in mitochondria. Thus, efficient sulfide detoxification mechanisms are required in mitochondria to ensure adequate energy production and consequently survival of the plant cell. Two enzymes have been recently described to catalyze sulfide detoxification in mitochondria of Arabidopsis thaliana, O-acetylserine(thiol)lyase C (OAS-TL C), and the sulfur dioxygenase (SDO) ethylmalonic encephalopathy protein 1 (ETHE1). Biochemical characterization of sulfide producing and consuming enzymes in mitochondria of plants is fundamental to understand the regulatory network that enables mitochondrial sulfide homeostasis under nonstressed and stressed conditions. In this chapter, we provide established protocols to determine the activity of the sulfide releasing enzyme β-cyanoalanine synthase as well as sulfide-consuming enzymes OAS-TL and SDO. Additionally, we describe a reliable and efficient method to purify OAS-TL proteins from plant material.

  2. RNA Editing in Plant Mitochondria

    Science.gov (United States)

    Hiesel, Rudolf; Wissinger, Bernd; Schuster, Wolfgang; Brennicke, Axel

    1989-12-01

    Comparative sequence analysis of genomic and complementary DNA clones from several mitochondrial genes in the higher plant Oenothera revealed nucleotide sequence divergences between the genomic and the messenger RNA-derived sequences. These sequence alterations could be most easily explained by specific post-transcriptional nucleotide modifications. Most of the nucleotide exchanges in coding regions lead to altered codons in the mRNA that specify amino acids better conserved in evolution than those encoded by the genomic DNA. Several instances show that the genomic arginine codon CGG is edited in the mRNA to the tryptophan codon TGG in amino acid positions that are highly conserved as tryptophan in the homologous proteins of other species. This editing suggests that the standard genetic code is used in plant mitochondria and resolves the frequent coincidence of CGG codons and tryptophan in different plant species. The apparently frequent and non-species-specific equivalency of CGG and TGG codons in particular suggests that RNA editing is a common feature of all higher plant mitochondria.

  3. 植物种子衰老与线粒体关系的研究进展%Research Progress on Plant Seed Aging and Mitochondria

    Institute of Scientific and Technical Information of China (English)

    田茜; 辛霞; 卢新雄; 陈晓岭; 张金梅

    2012-01-01

    种子的衰老是一个复杂的从量变到质变的生物学过程.种子衰老与线粒体功能异常密切相关,衰老的线粒体学说认为,线粒体中活性氧的过量产生是种子衰老的主要原因.深入了解种子衰老过程中线粒体的变化对于揭示种子衰老机理和种子安全保存具有重要意义.本文主要介绍了当前有关种子衰老过程中线粒体结构、呼吸作用和抗氧化系统的研究现状,并对种子衰老与线粒体关系研究中存在的问题进行了讨论.%Seed aging is a complex biological progress from quantitative change to qualitative change. Seed aging is closely related to the dysfunction of mitochondria. In the view of the "mitochondria aging theory" ,the excessive accumulation of ROS in mitochondria is the main reason of seed aging. Understanding the changes takes place in mitochondria during seed aging is important to reveal the mechanism of seed aging and ensure safe conservation of seeds. In this paper, the current process of mitochondrial structure, respiration and antioxidant systems during seed aging were reviewed. Moreover, problems in the study of seed aging and mitochondria were discussed.

  4. Respiratory chain supercomplexes in plant mitochondria.

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    Eubel, Holger; Heinemeyer, Jesco; Sunderhaus, Stephanie; Braun, Hans-Peter

    2004-12-01

    Supercomplexes are defined associations of protein complexes, which are important for several cellular functions. This "quintenary" organization level of protein structure recently was also described for the respiratory chain of plant mitochondria. Except succinate dehydrogenase (complex II), all complexes of the oxidative phosphorylation (OXPOS) system (complexes I, III, IV and V) were found to form part of supercomplexes. Compositions of these supramolecular structures were systematically investigated using digitonin solubilizations of mitochondrial fractions and two-dimensional Blue-native (BN) polyacrylamide gel electrophoresis. The most abundant supercomplex of plant mitochondria includes complexes I and III at a 1:2 ratio (I1 + III2 supercomplex). Furthermore, some supercomplexes of lower abundance could be described, which have I2 + III4, V2, III2 + IV(1-2), and I1 + III2 + IV(1-4) compositions. Supercomplexes consisting of complexes I plus III plus IV were proposed to be called "respirasome", because they autonomously can carry out respiration in the presence of ubiquinone and cytochrome c. Plant specific alternative oxidoreductases of the respiratory chain were not associated with supercomplexes under all experimental conditions tested. However, formation of supercomplexes possibly indirectly regulates alternative respiratory pathways in plant mitochondria on the basis of electron channeling. In this review, procedures to characterize the supermolecular organization of the plant respiratory chain and results concerning supercomplex structure and function are summarized and discussed.

  5. Protein oxidation in plant mitochondria as a stress indicator

    DEFF Research Database (Denmark)

    Møller, I.M.; Kristensen, B.K.

    2004-01-01

    Plant mitochondria produce reactive oxygen species (ROS) as an unavoidable side product of aerobic metabolism, but they have mechanisms for regulating this production such as the alternative oxidase. Once produced, ROS can be removed by several different enzyme systems. Finally, should the first ...... oxidation of cysteine and methionine side chains is an important mechanism for regulating enzyme activity. Mitochondria from both mammalian and plant tissues contain a number of oxidised proteins, but the relative abundance of these post-translationally modified forms is as yet unknown...... shock proteins. Plant mitochondria contain a number of different proteases, but their role in removing oxidatively damaged proteins is, as yet, unclear....

  6. Glycerolipid synthesis and lipid trafficking in plant mitochondria.

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    Michaud, Morgane; Prinz, William A; Jouhet, Juliette

    2017-02-01

    Lipid trafficking between mitochondria and other organelles is required for mitochondrial membrane biogenesis and signaling. This lipid exchange occurs by poorly understood nonvesicular mechanisms. In yeast and mammalian cells, this lipid exchange is thought to take place at contact sites between mitochondria and the ER or vacuolar membranes. Some proteins involved in the tethering between membranes or in the transfer of lipids in mitochondria have been identified. However, in plants, little is known about the synthesis of mitochondrial membranes. Mitochondrial membrane biogenesis is particularly important and noteworthy in plants as the lipid composition of mitochondrial membranes is dramatically changed during phosphate starvation and other stresses. This review focuses on the principal pathways involved in the synthesis of the most abundant mitochondrial glycerolipids in plants and the lipid trafficking that is required for plant mitochondria membrane biogenesis. © 2016 Federation of European Biochemical Societies.

  7. Redox conditions and protein oxidation in plant mitochondria

    DEFF Research Database (Denmark)

    Møller, Ian Max; Kasimova, Marina R.; Krab, Klaas

    2005-01-01

    Redox conditions and protein oxidation in plant mitochondria NAD(P)H has a central position in respiratory metabolism. It is produced by a large number of enzymes, e.g. the Krebs cycle dehydrogenases, in the mitochondrial matrix and is oxidised by, amongst others, the respiratory chain. Most...... of this NAD(P)H appears to be bound to proteins, in fact free NAD(P)H – an important parameter in metabolic regulation - has never been observed in mitochondria. We have estimated free and bound NAD(P)H in isolated plant mitochondria under different metabolic conditions. The fluorescence spectra of free...... and bound NADH was determined and used to deconvolute fluorescence spectra of actively respiring mitochondria. Most of the mitochondrial NADH is bound in states 2 and 4. The amount of free NADH is lower but relatively constant even increasing a little in state 3 where it is about equal to bound NADH...

  8. In silico Prediction of MicroRNAs in Plant Mitochondria

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    Jaiashre Sridhar

    2012-12-01

    Full Text Available MicroRNAs are endogenous, short (ca. 21 base, non-coding, post transcriptional, regulatory RNA molecules. These microRNAs (miRNAs are complementary to their target messenger RNAs, and bind principally to its 3' UTR. The conserved nature of miRNAs, and their high sequence complementarities of miRNA and its targets in plants, provides the basis for the easy identification of miRNA and its targets. Presence of miRNA in plant mitochondria is scantily studied. Identification of miRNA targets in plant mitochondria might indicate the involvement of miRNA in mitochondrial gene regulation and nuclear mitochondrial interactions. In this study, we used a computational approach to predict miRNA targets in plant mitochondria. The mitochondrial gene targets identified for miRNAs are located both in mitochondrial and nuclear compartments. This observation points to a fairly early origin of miRNAs. Besides, most of the targets identified can have copies in two compartments and suggest the possibility of miRNA mediated regulation. This study unfurls the possibility of regulating the plant mitochondrial genes by amending the miRNA genes in the nuclear compartment.

  9. Proteomic analysis of mitochondria: biological and clinical progresses in cancer.

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    Wang, Yang; Zhang, Jing; Li, Bin; He, Qing-Yu

    2017-10-01

    Mitochondria play important roles in regulating multiple biological processes and signalling pathways in eukaryotic cells, and mitochondrial dysfunction may result in a wide range of serious diseases, including cancer. With improvements in the identification of mitochondrial proteins, mitochondrial proteomics has made great achievements. In particular, this approach has been widely used to compare tumour cells at different stages of malignancy. Therefore, there is an urgent need to identify and characterize the function of mitochondrial proteins in cancer progression and to determine the involved mechanisms. Areas covered: We provide an overview of recent progress related to mitochondrial proteomics in cancer and the application of comparative mitochondrial proteomics in various biological processes, including apoptosis, necroptosis, autophagy and metastasis, as well as clinical progress in cancer. Proteomics-related reports were found using PubMed and Google Scholar databases. Expert commentary: Understanding both post-translational modification and post-translational processing is important in the comprehensive characterization of protein function. The application of comparative mitochondrial proteomics to investigate clinical samples and cancer cells will contribute to our understanding of the molecular interplay of mitochondrial proteins in the development of cancer. This approach will mine more biomarkers for diagnosis and prognosis and improve therapeutic outcomes among cancer patients.

  10. Frequent fusion and fission of plant mitochondria with unequal nucleoid distribution

    OpenAIRE

    Arimura, Shin-ichi; Yamamoto, Junko; Aida, Gen Paul; Nakazono, Mikio; Tsutsumi, Nobuhiro

    2004-01-01

    The balance between mitochondrial fusion and fission influences the reticular shape of mitochondria in yeasts. Little is known about whether mitochondria fusion occurs in plants. Plant mitochondria are usually more numerous and more grain-shaped than animal mitochondria. blast searches of the nuclear and mitochondrial genome sequences of Arabidopsis thaliana did not find any obvious homologue of mitochondrial fusion genes found in animals and yeasts. To determine whether mitochondrial fusion ...

  11. Protein import into plant mitochondria: signals, machinery, processing, and regulation.

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    Murcha, Monika W; Kmiec, Beata; Kubiszewski-Jakubiak, Szymon; Teixeira, Pedro F; Glaser, Elzbieta; Whelan, James

    2014-12-01

    The majority of more than 1000 proteins present in mitochondria are imported from nuclear-encoded, cytosolically synthesized precursor proteins. This impressive feat of transport and sorting is achieved by the combined action of targeting signals on mitochondrial proteins and the mitochondrial protein import apparatus. The mitochondrial protein import apparatus is composed of a number of multi-subunit protein complexes that recognize, translocate, and assemble mitochondrial proteins into functional complexes. While the core subunits involved in mitochondrial protein import are well conserved across wide phylogenetic gaps, the accessory subunits of these complexes differ in identity and/or function when plants are compared with Saccharomyces cerevisiae (yeast), the model system for mitochondrial protein import. These differences include distinct protein import receptors in plants, different mechanistic operation of the intermembrane protein import system, the location and activity of peptidases, the function of inner-membrane translocases in linking the outer and inner membrane, and the association/regulation of mitochondrial protein import complexes with components of the respiratory chain. Additionally, plant mitochondria share proteins with plastids, i.e. dual-targeted proteins. Also, the developmental and cell-specific nature of mitochondrial biogenesis is an aspect not observed in single-celled systems that is readily apparent in studies in plants. This means that plants provide a valuable model system to study the various regulatory processes associated with protein import and mitochondrial biogenesis.

  12. Plant mitochondria synthesize melatonin and enhance the tolerance of plants to drought stress.

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    Wang, Lin; Feng, Chao; Zheng, Xiaodong; Guo, Yan; Zhou, Fangfang; Shan, Dongqian; Liu, Xuan; Kong, Jin

    2017-10-01

    Synthesis of melatonin in mitochondria was reported in animals. However, there is no report on whether plant mitochondria also produce melatonin. Herein, we show that plant mitochondria are a major site for melatonin synthesis. In an in vitro study, isolated apple mitochondria had the capacity to generate melatonin. Subcellular localization analysis documented that an apple SNAT isoform, MzSNAT5, was localized in the mitochondria of both Arabidopsis protoplasts and apple callus cells. The kinetic analysis revealed that the recombinant MzSNAT5 protein exhibited high enzymatic activity to catalyze serotonin to N-acetylserotonin with the Km and Vmax of 55 μmol/L and 0.909 pmol/min/mg protein at 35°C, respectively; this pathway functioned over a wide range of temperatures from 5 to 75°C. In an in vivo study, MzSNAT5 was drought inducible. The transgenic Arabidopsis ectopically expressing MzSNAT5 elevated the melatonin level and, hence, enhanced drought tolerance. The mechanistic study indicated that the ectopically expressing MzSNAT5 allows plant mitochondria to increase melatonin synthesis. As a potent free radical scavenger, melatonin reduces the oxidative stress caused by the elevated reactive oxygen species which are generated under drought stress in plants. Our findings provide evidence that engineered melatonin-enriched plants exhibit enhanced oxidative tolerance. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Genes and processed paralogs co-exist in plant mitochondria.

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    Cuenca, Argelia; Petersen, Gitte; Seberg, Ole; Jahren, Anne Hoppe

    2012-04-01

    RNA-mediated gene duplication has been proposed to create processed paralogs in the plant mitochondrial genome. A processed paralog may retain signatures left by the maturation process of its RNA precursor, such as intron removal and no need of RNA editing. Whereas it is well documented that an RNA intermediary is involved in the transfer of mitochondrial genes to the nucleus, no direct evidence exists for insertion of processed paralogs in the mitochondria (i.e., processed and un-processed genes have never been found simultaneously in the mitochondrial genome). In this study, we sequenced a region of the mitochondrial gene nad1, and identified a number of taxa were two different copies of the region co-occur in the mitochondria. The two nad1 paralogs differed in their (a) presence or absence of a group II intron, and (b) number of edited sites. Thus, this work provides the first evidence of co-existence of processed paralogs and their precursors within the plant mitochondrial genome. In addition, mapping the presence/absence of the paralogs provides indirect evidence of RNA-mediated gene duplication as an essential process shaping the mitochondrial genome in plants.

  14. THE ROLE OF MITOCHONDRIA IN THE DEVELOPMENT AND PROGRESSION OF LUNG CANCER

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    Emily R Roberts

    2013-03-01

    Mitochondrial dysfunction in cancer has expanded to include defects in mitochondrial genomics and biogenesis, apoptotic signaling and mitochondrial dynamics. This review will focus on the role of mitochondria and their influence on cancer initiation, progression and treatment in the lung.

  15. An improved method with a wider applicability to isolate plant mitochondria for mtDNA extraction

    OpenAIRE

    2015-01-01

    Background Mitochondria perform a principal role in eukaryotic cells. Mutations in mtDNA can cause mitochondrial dysfunction and are frequently associated with various abnormalities during plant development. Extraction of plant mitochondria and mtDNA is the basic requirement for the characterization of mtDNA mutations and other molecular studies. However, currently available methods for mitochondria isolation are either tissue specific or species specific. Extracted mtDNA may contain substant...

  16. Do mitochondria play a role in remodelling lace plant leaves during programmed cell death?

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    Lane Stephanie

    2011-06-01

    Full Text Available Abstract Background Programmed cell death (PCD is the regulated death of cells within an organism. The lace plant (Aponogeton madagascariensis produces perforations in its leaves through PCD. The leaves of the plant consist of a latticework of longitudinal and transverse veins enclosing areoles. PCD occurs in the cells at the center of these areoles and progresses outwards, stopping approximately five cells from the vasculature. The role of mitochondria during PCD has been recognized in animals; however, it has been less studied during PCD in plants. Results The following paper elucidates the role of mitochondrial dynamics during developmentally regulated PCD in vivo in A. madagascariensis. A single areole within a window stage leaf (PCD is occurring was divided into three areas based on the progression of PCD; cells that will not undergo PCD (NPCD, cells in early stages of PCD (EPCD, and cells in late stages of PCD (LPCD. Window stage leaves were stained with the mitochondrial dye MitoTracker Red CMXRos and examined. Mitochondrial dynamics were delineated into four categories (M1-M4 based on characteristics including distribution, motility, and membrane potential (ΔΨm. A TUNEL assay showed fragmented nDNA in a gradient over these mitochondrial stages. Chloroplasts and transvacuolar strands were also examined using live cell imaging. The possible importance of mitochondrial permeability transition pore (PTP formation during PCD was indirectly examined via in vivo cyclosporine A (CsA treatment. This treatment resulted in lace plant leaves with a significantly lower number of perforations compared to controls, and that displayed mitochondrial dynamics similar to that of non-PCD cells. Conclusions Results depicted mitochondrial dynamics in vivo as PCD progresses within the lace plant, and highlight the correlation of this organelle with other organelles during developmental PCD. To the best of our knowledge, this is the first report of

  17. Specificity of DNA import into isolated mitochondria from plants and mammals

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    Koulintchenko M. V.

    2014-01-01

    Full Text Available Aim. Investigation of different features of DNA import into plant and human mitochondria, for a better understanding of mitochondrial genetics and generation of biotechnological tools. Methods. DNA up-take experiments with isolated plant mitochondria, using as substrates various sequences associated or not with the specific terminal inverted repeats (TIRs present at each end of the plant mitochondrial linear plasmids. Results. It was established that the DNA import efficiency has a non-linear dependence on DNA size. It was shown that import into plant mitochondria of DNA molecules of «medium» sizes, i. e. between 4 and 7 kb, barely has any sequence specificity: neither TIRs from the 11.6 kb Brassica plasmid, nor TIRs from the Zea mays S-plasmids influenced DNA import into Solanum tuberosum mitochondria. Conclusions. The data obtained support the hypothesis about species-specific import mechanism operating under the mitochondrial linear plasmids transfer into plant mitochondria.

  18. Effect of 6-ketocholestanol on FCCP- and DNP-induced uncoupling in plant mitochondria.

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    Vianello, A; Macri, F; Braidot, E; Mokhova, E N

    1995-05-22

    Effect of 6-ketocholestanol on FCCP-induced and DNP-induced uncoupling in beef liver and pea stem mitochondria was studied, under experimental conditions at which this steroid abolished the effect of low concentrations of FCCP and other most potent uncouplers in rat mitochondria [Starkov et al. (1994) FEBS Lett., 355, 305-308]. It is shown that, in both types of mitochondria, 6-ketocholestanol prevents or reverses the uncoupling induced by low concentrations of FCCP, but not that caused by high concentrations of FCCP or by any concentration of DNP. Progesterone and male sex hormones, showing recoupling capability in animal mitochondria, appear to be ineffective in the plant system. Cholesterol does not recouple in both animal and plant mitochondria. Plant steroids, such as beta-sitosterol and stigmasterol, are also without effect.

  19. Arsenate uncoupling of oxidative phosphorylation in isolated plant mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Wickes, W.A.; Wiskich, J.T.

    1976-01-01

    The uncoupling by arsenate of beetroot and cauliflower bud mitochondria showed the following characteristics: arsenate stimulation of respiration above the rate found with phosphate; inhibition of arsenate-stimulated respiration by phosphate; enhancement of arsenate-stimulated respiration by ADP; only partial prevention of this ADP-enhanced respiration by atractyloside; inhibition by oligomycin of the arsenate-stimulated respiration back to the phosphate rate; and the absence of any stimulatory effect of ADP in the presence of oligomycin. These results are qualitatively analogous to those reported for arsenate uncoupling in rat liver mitochondria. Arsenate stimulated malate oxidation, presumably by stimulating malate entry, in both beetroot and cauliflower bud mitochondria; however, high rates of oxidation, and presumably entry, were only sustained with arsenate in beetroot mitochondria. NADH was oxidized rapidly in cauliflower bud mitochondria in the presence of arsenate, showing that arsenate did not inhibit electron transfer processes.

  20. Human cultured cells are capable to incorporate isolated plant mitochondria loaded with exogenous DNA

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    Laktionov P. P.

    2012-07-01

    Full Text Available Aim. To investigate the possibility of human cultured cells to incorporate isolated mitochondria together with exogenous DNA introduced into organelles. Methods. Two approaches were used for this purpose, fluorescent labelling of mitochondria and/or DNA with subsequent analysis of the cells subjected to incubation by microscopy or by quantitative PCR. Results. We have shown that human cultured cells lines, HeLa and HUVEC, are capable to uptake isolated plant mitochondria and that this process depends on the incubation time and concentration of organelles present in medium. The incorporated mitochondria can serve as vehicles to deliver exogenous DNA into human cells, this DNA is then distributed in different cell compartments. Conclusions. These results are preliminary and need further investigations, including testing the possibility of human cells to incorporate the mitochondria of human or animal origin and creating genetic construction which could provide certain selectivity or stability of the transferred exogenous DNA upon cell uptake of the mitochondria as vectors.

  1. The role of mitochondria in the development and progression of lung cancer

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    Emily R Roberts

    2013-03-01

    Full Text Available The influence of mitochondria in human health and disease is a rapidly expanding topic in the scientific literature due to their integral roles in cellular death and survival. Mitochondrial biology and alterations in function were first linked to cancer in the 1920s with the discovery of the Warburg effect. The utilization of aerobic glycolysis in ATP synthesis was the first of many observations of metabolic reprogramming in cancer. Mitochondrial dysfunction in cancer has expanded to include defects in mitochondrial genomics and biogenesis, apoptotic signaling and mitochondrial dynamics. This review will focus on the role of mitochondria and their influence on cancer initiation, progression and treatment in the lung.

  2. The Role of Mitochondria in Cancer Induction, Progression and Changes in Metabolism.

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    Rogalinska, Malgorzata

    2016-01-01

    Mitochondria play important roles as energetic centers. Mutations in mitochondrial DNA (mtDNA) were found in several diseases, including cancers. Studies on cytoplasmic hybrids (cybrids) confirm that directed mutation introduced into mtDNA could be a reason for cancer induction. Mitochondria could also be a factor linking cancer transformation and progression. The importance of mitochondria in cancer also confirms their involvement in the resistance to treatment. Resistance to treatment of cancer cells can frequently be a reason for glycolysis acceleration. It could be explained by cancer cells' high proliferation index and high energy request. The involvement of mitochondria in metabolic disturbances of several metabolic diseases, including cancers, was reported. These data confirm that cancer induction, as well as cancer progression, could have metabolic roots. The aberrant products observed in prostate cells involved in the Krebs cycle could promote cancer progression. These multiple relationships between alterations on a genetic level translated into disturbances in cellular metabolism and their potential relation with epigenetic control of gene expression make cancerogenesis more complicated and prognoses' success in studies on cancer etiology more distant in time.

  3. Discovering the role of mitochondria in the iron deficiency-induced metabolic responses of plants.

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    Vigani, Gianpiero

    2012-01-01

    In plants, iron (Fe) deficiency-induced chlorosis is a major problem, affecting both yield and quality of crops. Plants have evolved multifaceted strategies, such as reductase activity, proton extrusion, and specialised storage proteins, to mobilise Fe from the environment and distribute it within the plant. Because of its fundamental role in plant productivity, several issues concerning Fe homeostasis in plants are currently intensively studied. The activation of Fe uptake reactions requires an overall adaptation of the primary metabolism because these activities need the constant supply of energetic substrates (i.e., NADPH and ATP). Several studies concerning the metabolism of Fe-deficient plants have been conducted, but research focused on mitochondrial implications in adaptive responses to nutritional stress has only begun in recent years. Mitochondria are the energetic centre of the root cell, and they are strongly affected by Fe deficiency. Nevertheless, they display a high level of functional flexibility, which allows them to maintain the viability of the cell. Mitochondria represent a crucial target of studies on plant homeostasis, and it might be of interest to concentrate future research on understanding how mitochondria orchestrate the reprogramming of root cell metabolism under Fe deficiency. In this review, I summarise what it is known about the effect of Fe deficiency on mitochondrial metabolism and morphology. Moreover, I present a detailed view of the possible roles of mitochondria in the development of plant responses to Fe deficiency, integrating old findings with new and discussing new hypotheses for future investigations.

  4. Mitochondria as a Possible Place for Initial Stages of Steroid Biosynthesis in Plants

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    Elena K. Shematorova

    2014-12-01

    Full Text Available With the aim of thorough comparison of steroidogenic systems of plants and animals, transgenic plants of Solanaceae family expressing CYP11A1 cDNA encoding cytochrome P450SCC of mammalian mitochondria were further analysed. Positive effect of CYP11A1 on resistance of the transgenic tobacco plants to the infection by fungal phytopathogene Botrytis cinerea was for the first time detected. Subtle changes in mitochondria of the transgenic Nicotiana tabacum plants expressing mammalian CYP11A1 cDNA were demonstrated by transmissive electron microscopy. The main components of the electron transfer chain of plant mitochondria were for the first time cloned and characterized. It was established that plants from the Solanacea family (tomato, tobacco and potato contain two different genes with similar exon-intron structures (all contain 8 exons encoding mitochondrial type ferredoxins (MFDX, and one gene for mitochondrial ferredoxin reductase (MFDXR. The results obtained point out on profound relatedness of electron transfer chains of P450-dependent monooxygenases in mammalian and plant mitochondria and support our previous findings about functional compatability of steroidogenic systems of Plantae and Animalia.

  5. Oxidation and reduction of pyridine nucleotides in alamethicin-permeabilized plant mitochondria

    DEFF Research Database (Denmark)

    Johansson, F.I.; Michalecka, A.M.; Møller, I.M.

    2004-01-01

    The inner mitochondrial membrane is selectively permeable, which limits the transport of solutes and metabolites across the membrane. This constitutes a problem when intramitochondrial enzymes are studied. The channel-forming antibiotic AlaM (alamethicin) was used as a potentially less invasive m...... environment not only in plant mitochondria but also in other membrane-enclosed compartments, such as intact cells, chloroplasts and peroxisomes....... method to permearbilize mitochondria and study the highly branched electron-transport chain in potato tuber (Solanum tuberosum) and pea leaf (Pisum sativum) mitochondria. We show that AlaM permeabilized the inner membrane of plant mitochondria to NAD(P)H, allowing the quantification of internal NAD......M-treated mitochondria was much higher than what has been previously measured by other techniques. Our results also show a difference in substrate specificities for complex I in mitochondria as compared with inside-out submitochondrial particles. AlaM facilitated the passage of cofactors to and from the mitochondrial...

  6. Biochemistry, proteomics, and phosphoproteomics of plant mitochondria from non-photosynthetic cells

    DEFF Research Database (Denmark)

    Havelund, Jesper; Thelen, Jay J.; Møller, Ian Max

    2013-01-01

    Mitochondria fulfill some basic roles in all plant cells. They supply the cell with energy in the form of ATP and reducing equivalents (NAD(P)H) and they provide the cell with intermediates for a range of biosynthetic pathways. In addition to this, mitochondria contribute to a number of specialized...... functions depending on the tissue and cell type, as well as environmental conditions. We will here review the biochemistry and proteomics of mitochondria from non-green cells and organs, which differ from those of photosynthetic organs in a number of respects. We will briefly cover purification...... of mitochondria and general biochemical properties such as oxidative phosphorylation. We will then mention a few adaptive properties in response to water stress, seed maturation and germination and the ability to function under hypoxic conditions. The discussion will mainly focus on Arabidopsis cell cultures...

  7. Slow passive diffusion of NAD+ between intact isolated plant mitochondria and suspending medium.

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    Neuburger, M; Douce, R

    1983-11-15

    Isolated potato (Solanum tuberosum) tuber mitochondria purified by isopycnic centrifugation in density gradients of Percoll were found to be highly intact, to be devoid of extramitochondrial contaminations and to retain a high rate of O2 consumption. When suspended in a medium that avoided rupture of the outer membrane, intact purified mitochondria progressively lost their NAD+ content by passive diffusion. This led to a slow decrease of oxoglutarate-dependent O2 consumption by isolated mitochondria. Addition of NAD+ to the medium restored the initial State-3 rate of oxoglutarate oxidation. The rate of NAD+ accumulation in the matrix space was concentration-dependent, exhibited Michaelis-Menten kinetics and was strongly inhibited by the analogue N-4-azido-2-nitrophenyl-4-aminobutyryl-NAD+.

  8. Biochemistry, proteomics and phosphoproteomics of plant mitochondria from non-photosynthetic cells

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    Jesper Foged Havelund

    2013-03-01

    Full Text Available Mitochondria fulfill some basic roles in all plant cells. They supply the cell with energy in the form of ATP and reducing equivalents (NAD(PH and they provide the cell with intermediates for a range of biosynthetic pathways. In addition to this, mitochondria contribute to a number of specialized functions depending on the tissue and cell type, as well as environmental conditions. We will here review the biochemistry and proteomics of mitochondria from non-green cells and organs, which differ from those of photosynthetic organs in a number of respects. We will briefly cover purification of mitochondria and general biochemical properties such as oxidative phosphorylation. We will then mention a few adaptive properties in response to water stress, seed maturation and germination and the ability to function under hypoxic conditions. The discussion will mainly focus on Arabidopsis cell cultures, etiolated germinating rice seedlings and potato tubers as model plants. It will cover the general proteome as well as the posttranslational modification protein phosphorylation. To date 64 phosphorylated mitochondrial proteins with a total of 103 phosphorylation sites have been identified.

  9. The role of mitochondria in plant development and stress tolerance

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    Proper cellular function requires orchestrated communication among cellular compartments and the ability of the cell to sense and respond to its environment. Plant cells contain three distinct compartments that house DNA. The nucleus contains the nuclear genome, which provides a majority of a cell's...

  10. THE ENERGETIC FUNCTIONS OF PLANT MITOCHONDRIA UNDER STRESS

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    Grabelnych O.I.

    2005-09-01

    Full Text Available This article reviews the involvement of the mitochondrial systems, which maintain the balance of cell energy at different stress conditions. It is shown the functioning of the alternative oxidase, free fatty acids, uncoupling proteins, the rotenone-insensitive NAD(PH dehydrogenases, the ADP/ATP-antiporter, the permeability transition pore and ATP-sensitive potassium channel (К+ATP. It is discussed data about physiological role of these systems in plant cell.

  11. Molecular studies of functional aspects of plant mitochondria. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Siedow, J.N.

    1992-03-03

    The goal of this research is to characterize the mechanism by which a protein encoded by mitochondrial genome of cms-T maize (URF13) interacts with a family of the compounds produced by certain fungi (T-toxins) to permeabilize biological membranes. The research carried out during the current funding period has focused on the structure of URF13, and the results support the validity of the three-helix model of URF13 and provide direct evidence for the oligomeric nature of at least some of the URF13 molecules in the membrane. In addition, the toxin binding studies have provided insight into the dynamic nature of the T-toxin:URF13 interaction and the extent to which Asp-39 is crucial to the interaction that leads to membrane pore formation. Additional knowledge of the structure of URF13 is needed if the nature of the interaction between URF13 and T-toxin to produce a hydrophilic pore within the membrane is to ultimately be understood.

  12. In vitro RNA editing in plant mitochondria does not require added energy.

    Science.gov (United States)

    Takenaka, Mizuki; Verbitskiy, Daniil; van der Merwe, Johannes A; Zehrmann, Anja; Plessmann, Uwe; Urlaub, Henning; Brennicke, Axel

    2007-06-12

    RNA editing in flowering plant mitochondria is investigated by in vitro assays. These cauliflower mitochondrial lysates require added NTP or dNTP. We have now resolved the reason for this requirement to be the inhibition of the RNA binding activity of the glutamate dehydrogenases (GDH). Both GDH1 and GDH2 were identified in RNA-protein cross-links. The inhibition of in vitro RNA editing by GDH is confirmed by the ability of the GDH-specific herbicide phosphinothricin to substitute for NTP. NADH and NADPH, but not NAD or NADP, can also replace NTP, suggesting that the NAD(P)H-binding-pocket configuration of the GDH contacts the RNA. RNA editing in plant mitochondria is thus intrinsically independent of added energy in the form of NTP.

  13. Mitochondria and cell death pathways in plants: Actions speak louder than words

    OpenAIRE

    Scott, Iain; Logan, David C

    2008-01-01

    The mitochondrion has a central role during programmed cell death (PCD) in animals, acting as both a sensor of death signals, and as an initiator of the biochemical processes which lead to the controlled destruction of the cell. In contrast to our extensive knowledge of animal cell death, the part played by mitochondria in the death of plant cells has received relatively little attention. Using a combination of whole-organism and cell-based models, we recently demonstrated that changes in mit...

  14. Using chemical biology to assess and modulate mitochondria: progress and challenges

    Science.gov (United States)

    Murphy, Michael P.

    2017-01-01

    Our understanding of the role of mitochondria in biomedical sciences has expanded considerably over the past decade. In addition to their well-known metabolic roles, mitochondrial are also central to signalling for various processes through the generation of signals such as ROS and metabolites that affect cellular homeostasis, as well as other processes such as cell death and inflammation. Thus, mitochondrial function and dysfunction are central to the health and fate of the cell. Consequently, there is considerable interest in better understanding and assessing the many roles of mitochondria. Furthermore, there is also a growing realization that mitochondrial are a promising drug target in a wide range of pathologies. The application of interdisciplinary approaches at the interface between chemistry and biology are opening up new opportunities to understand mitochondrial function and in assessing the role of the organelle in biology. This work and the experience thus gained are leading to the development of new classes of therapies. Here, we overview the progress that has been made to date on exploring the chemical biology of the organelle and then focus on future challenges and opportunities that face this rapidly developing field. PMID:28382206

  15. Reactive nitrogen species in mitochondria and their implications in plant energy status and hypoxic stress tolerance

    Directory of Open Access Journals (Sweden)

    Kapuganti Jagadis Gupta

    2016-03-01

    Full Text Available Hypoxic and anoxic conditions result in the energy crisis that leads to cell damage. Since mitochondria are the primary organelles for energy production, the support of these organelles in a functional state is an important task during oxygen deprivation. Plant mitochondria adapted the strategy to survive under hypoxia by keeping electron transport operative even without oxygen via the use of nitrite as a terminal electrons acceptor. The process of nitrite reduction to nitric oxide (NO in the mitochondrial electron transport chain recycles NADH and leads to a limited rate of ATP production. The produced ATP alongside with the ATP generated by fermentation supports the processes of transcription and translation required for hypoxic survival and recovery of plants. Non-symbiotic hemoglobins (called phytoglobins in plants scavenge NO and thus contribute to regeneration of NAD+ and nitrate required for the operation of anaerobic energy metabolism. This overall operation represents an important strategy of biochemical adaptation that results in the improvement of energy status and thereby in protection of plants in the conditions of hypoxic stress.

  16. Better Plants Progress Update Fall 2013

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-09-23

    This Progress Update summarizes the significant energy saving achievements and cumulative cost savings made by these industry leaders from 2010-2012. The update also shares the plans and priorities over the next year for the Better Plants Program to continue to advance energy efficiency in the industrial sector.

  17. Thioredoxin, a master regulator of the tricarboxylic acid cycle in plant mitochondria.

    Science.gov (United States)

    Daloso, Danilo M; Müller, Karolin; Obata, Toshihiro; Florian, Alexandra; Tohge, Takayuki; Bottcher, Alexandra; Riondet, Christophe; Bariat, Laetitia; Carrari, Fernando; Nunes-Nesi, Adriano; Buchanan, Bob B; Reichheld, Jean-Philippe; Araújo, Wagner L; Fernie, Alisdair R

    2015-03-17

    Plant mitochondria have a fully operational tricarboxylic acid (TCA) cycle that plays a central role in generating ATP and providing carbon skeletons for a range of biosynthetic processes in both heterotrophic and photosynthetic tissues. The cycle enzyme-encoding genes have been well characterized in terms of transcriptional and effector-mediated regulation and have also been subjected to reverse genetic analysis. However, despite this wealth of attention, a central question remains unanswered: "What regulates flux through this pathway in vivo?" Previous proteomic experiments with Arabidopsis discussed below have revealed that a number of mitochondrial enzymes, including members of the TCA cycle and affiliated pathways, harbor thioredoxin (TRX)-binding sites and are potentially redox-regulated. We have followed up on this possibility and found TRX to be a redox-sensitive mediator of TCA cycle flux. In this investigation, we first characterized, at the enzyme and metabolite levels, mutants of the mitochondrial TRX pathway in Arabidopsis: the NADP-TRX reductase a and b double mutant (ntra ntrb) and the mitochondrially located thioredoxin o1 (trxo1) mutant. These studies were followed by a comparative evaluation of the redistribution of isotopes when (13)C-glucose, (13)C-malate, or (13)C-pyruvate was provided as a substrate to leaves of mutant or WT plants. In a complementary approach, we evaluated the in vitro activities of a range of TCA cycle and associated enzymes under varying redox states. The combined dataset suggests that TRX may deactivate both mitochondrial succinate dehydrogenase and fumarase and activate the cytosolic ATP-citrate lyase in vivo, acting as a direct regulator of carbon flow through the TCA cycle and providing a mechanism for the coordination of cellular function.

  18. The free NADH concentration is kept constant in plant mitochondria under different metabolic conditions

    DEFF Research Database (Denmark)

    Kasimova, M.R.; Grigiene, J.; Krab, K.

    2006-01-01

    The reduced coenzyme NADH plays a central role in mitochondrial respiratory metabolism. However, reports on the amount of free NADH in mitochondria are sparse and contradictory. We first determined the emission spectrum of NADH bound to proteins using isothermal titration calorimetry combined...... with fluorescence spectroscopy. The NADH content of actively respiring mitochondria (from potato tubers [Solanum tuberosum cv Bintje]) in different metabolic states was then measured by spectral decomposition analysis of fluorescence emission spectra. Most of the mitochondrial NADH is bound to proteins...

  19. Dissecting the integrative antioxidant and redox systems in plant mitochondria. Effect of stress and S-nitrosylation.

    Directory of Open Access Journals (Sweden)

    Juan José Lázaro

    2013-11-01

    Full Text Available Mitochondrial respiration provides the energy needed to drive metabolic and transport processes in cells. Mitochondria are a significant site of reactive oxygen species (ROS production in plant cells, and redox-system components obey fine regulation mechanisms that are essential in protecting the mitochondrial integrity. In addition to ROS, there are compelling indications that nitric oxide (NO. can be generated in this organelle by both reductive and oxidative pathways. ROS and reactive nitrogen species (RNS play a key role in signaling but they can also be deleterious via oxidation of macromolecules. The high production of ROS obligates mitochondria to be provided with a set of ROS scavenging mechanisms. The first line of mitochondrial antioxidants is composed of superoxide dismutase and the enzymes of the ascorbate-glutathione cycle, which are not only able to scavenge ROS but also to repair cell damage and possibly serve as redox sensors. The dithiol-disulfide exchanges form independent signaling nodes and act as antioxidant defense mechanisms as well as sensor proteins modulating redox signaling during development and stress adaptation. The presence of thioredoxin (Trx, peroxiredoxin (Prx and sulfiredoxin (Srx in the mitochondria has been recently reported. Cumulative results obtained from studies in salt stress models have demonstrated that these redox proteins play a significant role in the establishment of salt tolerance. The Trx/Prx/Srx system may be subjected to a fine regulated mechanism involving post-translational modifications, among which S-glutathionylation and S-nitrosylation seem to exhibit a critical role that is just beginning to be understood. This review summarizes our current knowledge in antioxidative systems in plant mitochondria, their interrelationships, mechanisms of compensation and some unresolved questions, with special focus on their response to abiotic stress.

  20. Mitochondria and chloroplasts shared in animal and plant tissues: significance of communication.

    Science.gov (United States)

    Snyder, Christopher; Stefano, George B

    2015-05-25

    Mitochondria have long been recognized as the main source of energy production for the eukaryotic cell. Recent studies have found that the mitochondria have a variety of dynamic functions aside from the production of energy. It communicates bidirectionally with other organelles in order to modulate its energy balance efficiently, as well as maintain homeostasis, ultimately prolonging its own and the cell's longevity. The mitochondria achieves this level of regulation via specific and common bidirectional chemical messengers, especially involving the endoplasmic/sarcoplasmic reticulum (ER/SR), deoxyribonucleoside triphosphates (dNTP's), ATP and the generation of reactive oxygen species (ROS). Its communication network is also involved in stress associated events. In this regard, the activation of the Bax family proteins and the release of cytochrome c occurs during cellular stress. The communication can also promote apoptosis of the cell. When mitochondrial abnormalities cannot be dealt with, there is an increased chance that major illnesses like type 2 diabetes, Alzheimer's disease, and cancer may occur. Importantly, functioning chloroplasts can be found in animals, suggesting conserved chemical messengers during its evolutionary path. The dynamic capacity of mitochondria is also noted by their ability to function anaerobically. Indeed, this latter phenomenon may represent a return to an earlier developmental stage of mitochondria, suggesting certain disorders result from its untimely appearance.

  1. Unveiling interactions among mitochondria, caspase-like proteases, and the actin cytoskeleton during plant programmed cell death (PCD.

    Directory of Open Access Journals (Sweden)

    Christina E N Lord

    Full Text Available Aponogeton madagascariensis produces perforations over its leaf surface via programmed cell death (PCD. PCD begins between longitudinal and transverse veins at the center of spaces regarded as areoles, and continues outward, stopping several cells from these veins. The gradient of PCD that exists within a single areole of leaves in an early stage of development was used as a model to investigate cellular dynamics during PCD. Mitochondria have interactions with a family of proteases known as caspases, and the actin cytoskeleton during metazoan PCD; less is known regarding these interactions during plant PCD. This study employed the actin stain Alexa Fluor 488 phalloidin, the actin depolymerizer Latrunculin B (Lat B, a synthetic caspase peptide substrate and corresponding specific inhibitors, as well as the mitochondrial pore inhibitor cyclosporine A (CsA to analyze the role of these cellular constituents during PCD. Results depicted that YVADase (caspase-1 activity is higher during the very early stages of perforation formation, followed by the bundling and subsequent breakdown of actin. Actin depolymerization using Lat B caused no change in YVADase activity. In vivo inhibition of YVADase activity prevented PCD and actin breakdown, therefore substantiating actin as a likely substrate for caspase-like proteases (CLPs. The mitochondrial pore inhibitor CsA significantly decreased YVADase activity, and prevented both PCD and actin breakdown; therefore suggesting the mitochondria as a possible trigger for CLPs during PCD in the lace plant. To our knowledge, this is the first in vivo study using either caspase-1 inhibitor (Ac-YVAD-CMK or CsA, following which the actin cytoskeleton was examined. Overall, our findings suggest the mitochondria as a possible upstream activator of YVADase activity and implicate these proteases as potential initiators of actin breakdown during perforation formation via PCD in the lace plant.

  2. AtMic60 Is Involved in Plant Mitochondria Lipid Trafficking and Is Part of a Large Complex.

    Science.gov (United States)

    Michaud, Morgane; Gros, Valérie; Tardif, Marianne; Brugière, Sabine; Ferro, Myriam; Prinz, William A; Toulmay, Alexandre; Mathur, Jaideep; Wozny, Michael; Falconet, Denis; Maréchal, Eric; Block, Maryse A; Jouhet, Juliette

    2016-03-07

    The mitochondrion is an organelle originating from an endosymbiotic event and playing a role in several fundamental processes such as energy production, metabolite syntheses, and programmed cell death. This organelle is delineated by two membranes whose synthesis requires an extensive exchange of phospholipids with other cellular organelles such as endoplasmic reticulum (ER) and vacuolar membranes in yeast. These transfers of phospholipids are thought to occur by a non-vesicular pathway at contact sites between two closely apposed membranes. In plants, little is known about the biogenesis of mitochondrial membranes. Contact sites between ER and mitochondria are suspected to play a similar role in phospholipid trafficking as in yeast, but this has never been demonstrated. In contrast, it has been shown that plastids are able to transfer lipids to mitochondria during phosphate starvation. However, the proteins involved in such transfer are still unknown. Here, we identified in Arabidopsis thaliana a large lipid-enriched complex called the mitochondrial transmembrane lipoprotein (MTL) complex. The MTL complex contains proteins located in the two mitochondrial membranes and conserved in all eukaryotic cells, such as the TOM complex and AtMic60, a component of the MICOS complex. We demonstrate that AtMic60 contributes to the export of phosphatidylethanolamine from mitochondria and the import of galactoglycerolipids from plastids during phosphate starvation. Furthermore, AtMic60 promotes lipid desorption from membranes, likely as an initial step for lipid transfer, and binds to Tom40, suggesting that AtMic60 could regulate the tethering between the inner and outer membranes of mitochondria.

  3. The multiplicity of dehydrogenases in the electron transport chain of plant mitochondria

    DEFF Research Database (Denmark)

    Rasmusson, Allan G; Geisler, Daniela A; Møller, Ian Max

    2008-01-01

    The electron transport chain in mitochondria of different organisms contains a mixture of common and specialised components. The specialised enzymes form branches to the universal electron path, especially at the level of ubiquinone, and allow the chain to adjust to different cellular and metabolic...

  4. Biochemistry, proteomics, and phosphoproteomics of plant mitochondria from non-photosynthetic cells

    DEFF Research Database (Denmark)

    Havelund, Jesper; Thelen, Jay J.; Møller, Ian Max

    2013-01-01

    functions depending on the tissue and cell type, as well as environmental conditions. We will here review the biochemistry and proteomics of mitochondria from non-green cells and organs, which differ from those of photosynthetic organs in a number of respects. We will briefly cover purification...

  5. Origins of the plant chloroplasts and mitochondria based on comparisons of 5S ribosomal RNAs

    Science.gov (United States)

    Delihas, N.; Fox, G. E.

    1987-01-01

    In this paper, we provide macromolecular comparisons utilizing the 5S ribosomal RNA structure to suggest extant bacteria that are the likely descendants of chloroplast and mitochondria endosymbionts. The genetic stability and near universality of the 5S ribosomal gene allows for a useful means to study ancient evolutionary changes by macromolecular comparisons. The value in current and future ribosomal RNA comparisons is in fine tuning the assignment of ancestors to the organelles and in establishing extant species likely to be descendants of bacteria involved in presumed multiple endosymbiotic events.

  6. DNA Import into Mitochondria.

    Science.gov (United States)

    Konstantinov, Yu M; Dietrich, A; Weber-Lotfi, F; Ibrahim, N; Klimenko, E S; Tarasenko, V I; Bolotova, T A; Koulintchenko, M V

    2016-10-01

    In recent decades, it has become evident that the condition for normal functioning of mitochondria in higher eukaryotes is the presence of membrane transport systems of macromolecules (proteins and nucleic acids). Natural competence of the mitochondria in plants, animals, and yeasts to actively uptake DNA may be directly related to horizontal gene transfer into these organelles occurring at much higher rate compared to the nuclear and chloroplast genomes. However, in contrast with import of proteins and tRNAs, little is known about the biological role and molecular mechanism underlying import of DNA into eukaryotic mitochondria. In this review, we discuss current state of investigations in this area, particularly specificity of DNA import into mitochondria and its features in plants, animals, and yeasts; a tentative mechanism of DNA import across the mitochondrial outer and inner membranes; experimental data evidencing several existing, but not yet fully understood mechanisms of DNA transfer into mitochondria. Currently available data regarding transport of informational macromolecules (DNA, RNA, and proteins) into the mitochondria do not rule out that the mechanism of protein and tRNA import as well as tRNA and DNA import into the mitochondria may partially overlap.

  7. What happens to plant mitochondria under low oxygen? An omics review of the responses to low oxygen and reoxygenation.

    Science.gov (United States)

    Shingaki-Wells, Rachel; Millar, A Harvey; Whelan, James; Narsai, Reena

    2014-10-01

    Floods can rapidly submerge plants, limiting oxygen to the extent that oxidative phosphorylation no longer generates adequate ATP supplies. Low-oxygen tolerant plants, such as rice, are able to adequately respond to low oxygen by successfully remodelling primary and mitochondrial metabolism to partially counteract the energy crisis that ensues. In this review, we discuss how plants respond to low-oxygen stress at the transcriptomic, proteomic, metabolomic and enzyme activity levels, particularly focusing on mitochondria and interacting pathways. The role of reactive oxygen species and nitrite as an alternative electron acceptor as well as their links to respiratory chain components is discussed. By making intra-kingdom as well as cross-kingdom comparisons, conserved mechanisms of anoxia tolerance are highlighted as well as tolerance mechanisms that are specific to anoxia-tolerant rice during germination and in coleoptiles. We discuss reoxygenation as an often overlooked, yet essential stage of this environmental stress and consider the possibility that changes occurring during low oxygen may also provide benefits upon re-aeration. Finally, we consider what it takes to be low-oxygen tolerant and argue that alternative mechanisms of ATP production, glucose signalling, starch/sucrose signalling as well as reverse metabolism of fermentation end products promote the survival of rice after this debilitating stress.

  8. Increasing CO[sub 2] concentration inhibits cytochrome c oxidase (cytox) in vitro, cytochrome pathway (cytpath) activity in plant mitochondria and dark respiration in plant tissue

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Meler, M.A.; Drake, B.G.; Jacob, J. (Smithsonian Environmental Research Center, Edgewater, MD (United States)); Ribas-Carbo, M.; Siedow, J.N. (Duke Univ., Durham, NC (United States)); Aranda, X.; Azcon-Bieto, J.; Palet, A. (Universitat Barcelona (Spain))

    1994-06-01

    Dark respiration is inhibited in many plant be exposure to elevated atmospheric CO[sub 2] concentration. The addition of 0.2mM free CO[sub 2] in the reaction medium decreased citpath activity in Pisum sativum and Glycine max mitochondria at pH 7.2, possibly by inhibiting cytox. Under similar conditions, activity of purified cytox from beef heart was also inhibited. Cytox activity extracted from plants grown in elevated CO[sub 2] for 7 years was lower than in those grown in normal ambient. The relationship among these effects and the rate of respiration as well as the role of the alternative pathway in each case will be discussed.

  9. Progressive Plant Growing Has Business Blooming

    Science.gov (United States)

    2006-01-01

    In 1997, AgriHouse, Inc. (d.b.a. Aeroponics International), a leading agri-biology company, united with NASA and BioServe Space Technologies, a nonprofit, NASA-sponsored partnership research center, to design a soil-less plant-growth experiment to be performed in microgravity, aboard the Mir space station. This experiment aimed to gauge the effectiveness of a non-pesticide solution on the immune responses of bean plants. In essence, the research consortium was looking for a means of keeping plants free from infection, without having to rely on the use of pesticides. This research, combined with follow-on grants from NASA, has helped Berthoud, Colorado-based AgriHouse gain credibility in the commercial marketplace with related technology and gross the capital necessary to conduct further research in a new-age field known as bio-pharming.

  10. Mitochondria change dynamics and morphology during grapevine leaf senescence.

    Directory of Open Access Journals (Sweden)

    Cristina Ruberti

    Full Text Available Leaf senescence is the last stage of development of an organ and is aimed to its ordered disassembly and nutrient reallocation. Whereas chlorophyll gradually degrades during senescence in leaves, mitochondria need to maintain active to sustain the energy demands of senescing cells. Here we analysed the motility and morphology of mitochondria in different stages of senescence in leaves of grapevine (Vitis vinifera, by stably expressing a GFP (green fluorescent protein reporter targeted to these organelles. Results show that mitochondria were less dynamic and markedly changed morphology during senescence, passing from the elongated, branched structures found in mature leaves to enlarged and sparse organelles in senescent leaves. Progression of senescence in leaves was not synchronous, since changes in mitochondria from stomata were delayed. Mitochondrial morphology was also analysed in grapevine cell cultures. Mitochondria from cells at the end of their growth curve resembled those from senescing leaves, suggesting that cell cultures might represent a useful model system for senescence. Additionally, senescence-associated mitochondrial changes were observed in plants treated with high concentrations of cytokinins. Overall, morphology and dynamics of mitochondria might represent a reliable senescence marker for plant cells.

  11. Mitochondria change dynamics and morphology during grapevine leaf senescence.

    Science.gov (United States)

    Ruberti, Cristina; Barizza, Elisabetta; Bodner, Martina; La Rocca, Nicoletta; De Michele, Roberto; Carimi, Francesco; Lo Schiavo, Fiorella; Zottini, Michela

    2014-01-01

    Leaf senescence is the last stage of development of an organ and is aimed to its ordered disassembly and nutrient reallocation. Whereas chlorophyll gradually degrades during senescence in leaves, mitochondria need to maintain active to sustain the energy demands of senescing cells. Here we analysed the motility and morphology of mitochondria in different stages of senescence in leaves of grapevine (Vitis vinifera), by stably expressing a GFP (green fluorescent protein) reporter targeted to these organelles. Results show that mitochondria were less dynamic and markedly changed morphology during senescence, passing from the elongated, branched structures found in mature leaves to enlarged and sparse organelles in senescent leaves. Progression of senescence in leaves was not synchronous, since changes in mitochondria from stomata were delayed. Mitochondrial morphology was also analysed in grapevine cell cultures. Mitochondria from cells at the end of their growth curve resembled those from senescing leaves, suggesting that cell cultures might represent a useful model system for senescence. Additionally, senescence-associated mitochondrial changes were observed in plants treated with high concentrations of cytokinins. Overall, morphology and dynamics of mitochondria might represent a reliable senescence marker for plant cells.

  12. [Research progress on plant diversity conservation in sand dune areas].

    Science.gov (United States)

    Liu, Zhi-min; Ma, Jun-ling

    2008-01-01

    The landscape in sand dune areas is characterized by the alternate distribution of sand dune and interdune lowland, and the unique floras in these areas are some endemic or rare plant species. In recent years, the decrease in plant species richness and the disappearance of some endemic or rare plant species in these areas have been received special attention, which were listed in the Program of International Biodiversity Conservation, and studied in many countries and districts. In this paper, the research progress in these fields was summarized from the aspects of significance of plant diversity conservation, formation mechanisms of plant diversity, ways of plant diversity conservation, roles of plant diversity research in the development of ecological theories, and important issues in operating plant diversity conservation project. To conserve plant diversity in sand dune areas, attentions should be paid to the differences in conservation goals (to maintain high species richness or to conserve endemic or rare species) among different regions, and the balances between the stabilization of active sand and the conservation of endemic or rare species, and the maintenance of high species richness and the conservation of endemic or rare species. It needed also to consider the sand dune and the interdune lowland as a unified landscape unit to explore the impacts of disturbances and habitat fragment on plant diversity.

  13. Ancient Plant Glyoxylate/Succinic Semialdehyde Reductases: GLYR1s Are Cytosolic, Whereas GLYR2s Are Localized to Both Mitochondria and Plastids

    Directory of Open Access Journals (Sweden)

    Barry J. Shelp

    2017-04-01

    Full Text Available Plant NADPH-dependent glyoxylate/succinic semialdehyde reductases 1 and 2 (GLYR1 and GLYR2 are considered to be involved in detoxifying harmful aldehydes, thereby preserving plant health during exposure to various abiotic stresses. Phylogenetic analysis revealed that the two GLYR isoforms appeared in the plant lineage prior to the divergence of the Chlorophyta and Streptophyta, which occurred approximately 750 million years ago. Green fluorescent protein fusions of apple (Malus x domestica Borkh., rice (Oryza sativa L. and Arabidopsis thaliana [L.] Heynh GLYRs were transiently expressed in tobacco (Nicotiana tabaccum L. suspension cells or Arabidopsis protoplasts, as well in methoxyfenozide-induced, stably transformed Arabidopsis seedlings. The localization of apple GLYR1 confirmed that this isoform is cytosolic, whereas apple, rice and Arabidopsis GLYR2s were localized to both mitochondria and plastids. These findings highlight the potential involvement of GLYRs within distinct compartments of the plant cell.

  14. Astaxanthin protects against early burn-wound progression in rats by attenuating oxidative stress-induced inflammation and mitochondria-related apoptosis

    Science.gov (United States)

    Fang, Quan; Guo, Songxue; Zhou, Hanlei; Han, Rui; Wu, Pan; Han, Chunmao

    2017-01-01

    Burn-wound progression can occur in the initial or peri-burn area after a deep burn injury. The stasis zone has a higher risk of deterioration mediated by multiple factors but is also considered salvageable. Astaxanthin (ATX), which is extracted from some marine organisms, is a natural compound with a strong antioxidant effect that has been reported to attenuate organ injuries caused by traumatic injuries. Hence, we investigated the potential effects of ATX on preventing early burn-wound progression. A classic “comb” burn rat model was established in this study for histological and biological assessments, which revealed that ATX, particularly higher doses, alleviated histological deterioration in the stasis zone. Additionally, we observed dose-dependent improvements in oxidative stress and the release of inflammatory mediators after ATX treatment. Furthermore, ATX dose-dependently attenuated burn-induced apoptosis in the wound areas, and this effect was accompanied by increases in Akt and Bad phosphorylation and a downregulation of cytochrome C and caspase expression. In addition, the administration of Ly 294002 further verified the effect of ATX. In summary, we demonstrated that ATX protected against early burn-wound progression in a rat deep-burn model. This protection might be mediated by the attenuation of oxidative stress-induced inflammation and mitochondria-related apoptosis. PMID:28128352

  15. Research progress in mitochondria-targeted antioxidants%线粒体靶向抗氧化剂研究进展

    Institute of Scientific and Technical Information of China (English)

    樊鹏程; 葛越; 蒋炜; 景临林; 马慧萍; 贾正平

    2015-01-01

    线粒体是细胞呼吸的主要场所,在细胞的生命周期中扮演重要角色,三羧酸循环和氧化磷酸化都是在线粒体中进行。线粒体功能障碍可导致一系列疾病,如缺血‐再灌注损伤、败血症和糖尿病等。线粒体是神经退行性病变的治疗靶点,也是药物转运策略研究的引人注目的靶位。虽然线粒体所介导的疾病进程的分子机制尚未完全阐明,但氧化应激是关键的环节。开发线粒体靶向的抗氧化应激保护药物具有诱人的前景。线粒体靶向抗氧化剂是指以线粒体为作用靶位的具有抗氧化作用的药物。该文介绍了现有的线粒体靶向抗氧化剂的概念、分类及其疾病治疗研究进展。%Mitochondria are the main places of cellular respiration as well as the citric acid cycle and oxidative phospho‐rylation .It plays an important role in controlling the life and death of cells .Mitochondrial dysfunction leads to a series of human diseases such as ischemia‐reperfusion injury ,sepsis and diabetes .Mitochondrial become an attractive target for drug transporters strategy and therapeutic targets for neurodegeneration .Although the molecular mechanisms responsible for mitochondria media‐ted disease processes are not fully elucidated yet ,the oxidative stress appears to be critical .Accordingly ,strategies are being de‐veloped for the targeted delivery of antioxidants to mitochondria .The prospect of development of mitochondrial targeted drugs with anti‐oxidative stress protection is tempting .Mitochondrial targeting antioxidants were the antioxidant drugs which took mi‐tochondria as the target site .In this review ,weintroduced the conception and classification of mitochondrial targeted antioxidants and the research progress of disease treatment by mitochondrial targeted antioxidants .

  16. HBsAg inhibits the translocation of JTB into mitochondria in HepG2 cells and potentially plays a role in HCC progression.

    Directory of Open Access Journals (Sweden)

    Yun-Peng Liu

    Full Text Available BACKGROUND AND AIMS: The expression of the jumping translocation breakpoint (JTB gene is upregulated in malignant liver tissues; however, JTB is associated with unbalanced translocations in many other types of cancer that suppress JTB expression. No comprehensive analysis on its function in human hepatocellular carcinoma (HCC has been performed to date. We aimed to define the biological consequences for interaction between JTB and HBsAg in HCC cell lines. METHODS: We employed the stable transfection to establish small HBsAg expressing HepG2 cell line, and stably silenced the JTB expression using short hairpin RNA in HepG2 cell line. The effects of JTB and small HBsAg in vitro were determined by assessing cell apoptosis and motility. RESULTS: Silencing of JTB expression promoted cancer cell motility and reduced cell apoptosis, which was significantly enhanced by HBs expression. Expression of HBsAg inhibited the translocation of JTB to the mitochondria. Furthermore, silencing of the JTB resulted in an increase in the phosphorylation of p65 in HepG2 cells and HepG2-HBs cells, whereas HBsAg expression decreased the phosphorylation of p65. The silencing of JTB in HepG2-HBs cells conferred increased advantages in cell motility and anti-apoptosis. CONCLUSION: HBsAg inhibited the translocation of JTB to the mitochondria and decreased the phosphorylation of p65 through the interaction with JTB, After JTB knockdown, HBsAg exhibited a stronger potential to promote tumor progression. Our data suggested that JTB act as a tumor suppressor gene in regards to HBV infection and its activation might be applied as a therapeutic strategy for in control of HBV related HCC development.

  17. Mitochondria in lung disease.

    Science.gov (United States)

    Cloonan, Suzanne M; Choi, Augustine M K

    2016-03-01

    Mitochondria are a distinguishing feature of eukaryotic cells. Best known for their critical function in energy production via oxidative phosphorylation (OXPHOS), mitochondria are essential for nutrient and oxygen sensing and for the regulation of critical cellular processes, including cell death and inflammation. Such diverse functional roles for organelles that were once thought to be simple may be attributed to their distinct heteroplasmic genome, exclusive maternal lineage of inheritance, and ability to generate signals to communicate with other cellular organelles. Mitochondria are now thought of as one of the cell's most sophisticated and dynamic responsive sensing systems. Specific signatures of mitochondrial dysfunction that are associated with disease pathogenesis and/or progression are becoming increasingly important. In particular, the centrality of mitochondria in the pathological processes and clinical phenotypes associated with a range of lung diseases is emerging. Understanding the molecular mechanisms regulating the mitochondrial processes of lung cells will help to better define phenotypes and clinical manifestations associated with respiratory disease and to identify potential diagnostic and therapeutic targets.

  18. Huntington's Disease and Mitochondria.

    Science.gov (United States)

    Jodeiri Farshbaf, Mohammad; Ghaedi, Kamran

    2017-06-21

    Huntington's disease (HD) as an inherited neurodegenerative disorder leads to neuronal loss in striatum. Progressive motor dysfunction, cognitive decline, and psychiatric disturbance are the main clinical symptoms of the HD. This disease is caused by expansion of the CAG repeats in exon 1 of the huntingtin which encodes Huntingtin protein (Htt). Various cellular and molecular events play role in the pathology of HD. Mitochondria as important organelles play crucial roles in the most of neurodegenerative disorders like HD. Critical roles of the mitochondria in neurons are ATP generation, Ca(2+) buffering, ROS generation, and antioxidant activity. Neurons as high-demand energy cells closely related to function, maintenance, and dynamic of mitochondria. In the most neurological disorders, mitochondrial activities and dynamic are disrupted which associate with high ROS level, low ATP generation, and apoptosis. Accumulation of mutant huntingtin (mHtt) during this disease may evoke mitochondrial dysfunction. Here, we review recent findings to support this hypothesis that mHtt could cause mitochondrial defects. In addition, by focusing normal huntingtin functions in neurons, we purpose mitochondria and Huntingtin association in normal condition. Moreover, mHtt affects various cellular signaling which ends up to mitochondrial biogenesis. So, it could be a potential candidate to decline ATP level in HD. We conclude how mitochondrial biogenesis plays a central role in the neuronal survival and activity and how mHtt affects mitochondrial trafficking, maintenance, integrity, function, dynamics, and hemostasis and makes neurons vulnerable to degeneration in HD.

  19. Folates in plants: research advances and progress in crop biofortification

    Science.gov (United States)

    Gorelova, Vera; Ambach, Lars; Rébeillé, Fabrice; Stove, Christophe; Van Der Straeten, Dominique

    2017-03-01

    Folates, also known as B9 vitamins, serve as donors and acceptors in one-carbon (C1) transfer reactions. The latter are involved in synthesis of many important biomolecules, such as amino acids, nucleic acids and vitamin B5. Folates also play a central role in the methyl cycle that provides one-carbon groups for methylation reactions. The important functions fulfilled by folates make them essential in all living organisms. Plants, being able to synthesize folates de novo, serve as an excellent dietary source of folates for animals that lack the respective biosynthetic pathway. Unfortunately, the most important staple crops such as rice, potato and maize are rather poor sources of folates. Insufficient folate consumption is known to cause severe developmental disorders in humans. Two approaches are employed to fight folate deficiency: pharmacological supplementation in the form of folate pills and biofortification of staple crops. As the former approach is considered rather costly for the major part of the world population, biofortification of staple crops is viewed as a decent alternative in the struggle against folate deficiency. Therefore strategies, challenges and recent progress of folate enhancement in plants will be addressed in this review. Apart from the ever-growing need for the enhancement of nutritional quality of crops, the world population faces climate change catastrophes or environmental stresses, such as elevated temperatures, drought, salinity that severely affect growth and productivity of crops. Due to immense diversity of their biochemical functions, folates take part in virtually every aspect of plant physiology. Any disturbance to the plant folate metabolism leads to severe growth inhibition and, as a consequence, to a lower productivity. Whereas today’s knowledge of folate biochemistry can be considered very profound, evidence on the physiological roles of folates in plants only starts to emerge. In the current review we will discuss the

  20. Degenerate mitochondria

    OpenAIRE

    van der Giezen, Mark; Tovar, Jorge

    2005-01-01

    Mitochondria are the main sites of biological energy generation in eukaryotes. These organelles are remnants of a bacterial endosymbiont that took up residence inside a host cell over 1,500 million years ago. Comparative genomics studies suggest that the mitochondrion is monophyletic in origin. Thus, the original mitochondrial endosymbiont has evolved independently in anaerobic and aerobic environments that are inhabited by diverse eukaryotic lineages. This process has resulted in a collectio...

  1. The D3cpv Cameleon reports Ca²⁺ dynamics in plant mitochondria with similar kinetics of the YC3.6 Cameleon, but with a lower sensitivity.

    Science.gov (United States)

    Loro, G; Ruberti, C; Zottini, M; Costa, A

    2013-01-01

    Mitochondria are key organelles involved in many aspects of plant physiology and, their ability to generate specific Ca²⁺ signatures in response to abiotic and biotic stimuli has been reported as one of their roles. The recent identification of the mammalian mitochondrial Ca²⁺ uniporter opens a new research area in plant biology. To study the mitochondrial Ca²⁺ handling, it is essential to have a reliable probe. Here we have reported the generation of an Arabidopsis transgenic line expressing the genetically encoded probe Cameleon D3cpv targeted to mitochondria, and compared its properties with the already known Cameleon YC3.6.

  2. Bacterial- and plant-type phosphoenolpyruvate carboxylase isozymes from developing castor oil seeds interact in vivo and associate with the surface of mitochondria.

    Science.gov (United States)

    Park, Joonho; Khuu, Nicholas; Howard, Alexander S M; Mullen, Robert T; Plaxton, William C

    2012-07-01

    Phosphoenolpyruvate carboxylase (PEPC) from developing castor oil seeds (COS) exists as two distinct oligomeric isoforms. The typical class-1 PEPC homotetramer consists of 107-kDa plant-type PEPC (PTPC) subunits, whereas the allosterically desensitized 910-kDa class-2 PEPC hetero-octamer arises from the association of class-1 PEPC with 118-kDa bacterial-type PEPC (BTPC) subunits. The in vivo interaction and subcellular location of COS BTPC and PTPC were assessed by imaging fluorescent protein (FP)-tagged PEPCs in tobacco suspension-cultured cells. The BTPC-FP mainly localized to cytoplasmic punctate/globular structures, identified as mitochondria by co-immunostaining of endogenous cytochrome oxidase. Inhibition of respiration with KCN resulted in proportional decreases and increases in mitochondrial versus cytosolic BTPC-FP, respectively. The FP-PTPC and NLS-FP-PTPC (containing an appended nuclear localization signal, NLS) localized to the cytosol and nucleus, respectively, but both co-localized with mitochondrial-associated BTPC when co-expressed with BTPC-FP. Transmission electron microscopy of immunogold-labeled developing COS revealed that BTPC and PTPC are localized at the mitochondrial (outer) envelope, as well as the cytosol. Moreover, thermolysin-sensitive BTPC and PTPC polypeptides were detected on immunoblots of purified COS mitochondria. Overall, our results demonstrate that: (i) COS BTPC and PTPC interact in vivo as a class-2 PEPC complex that associates with the surface of mitochondria, (ii) BTPC's unique and divergent intrinsically disordered region mediates its interaction with PTPC, whereas (iii) the PTPC-containing class-1 PEPC is entirely cytosolic. We hypothesize that mitochondrial-associated class-2 PEPC facilitates rapid refixation of respiratory CO(2) while sustaining a large anaplerotic flux to replenish tricarboxylic acid cycle C-skeletons withdrawn for biosynthesis.

  3. Future Scenarios for Plant Virus Pathogens as Climate Change Progresses.

    Science.gov (United States)

    Jones, R A C

    2016-01-01

    Knowledge of how climate change is likely to influence future virus disease epidemics in cultivated plants and natural vegetation is of great importance to both global food security and natural ecosystems. However, obtaining such knowledge is hampered by the complex effects of climate alterations on the behavior of diverse types of vectors and the ease by which previously unknown viruses can emerge. A review written in 2011 provided a comprehensive analysis of available data on the effects of climate change on virus disease epidemics worldwide. This review summarizes its findings and those of two earlier climate change reviews and focuses on describing research published on the subject since 2011. It describes the likely effects of the full range of direct and indirect climate change parameters on hosts, viruses and vectors, virus control prospects, and the many information gaps and deficiencies. Recently, there has been encouraging progress in understanding the likely effects of some climate change parameters, especially over the effects of elevated CO2, temperature, and rainfall-related parameters, upon a small number of important plant viruses and several key insect vectors, especially aphids. However, much more research needs to be done to prepare for an era of (i) increasingly severe virus epidemics and (ii) increasing difficulties in controlling them, so as to mitigate their detrimental effects on future global food security and plant biodiversity.

  4. Progress in Genome Editing Technology and Its Application in Plants

    Science.gov (United States)

    Zhang, Kai; Raboanatahiry, Nadia; Zhu, Bin; Li, Maoteng

    2017-01-01

    Genome editing technology (GET) is a versatile approach that has progressed rapidly as a mechanism to alter the genotype and phenotype of organisms. However, conventional genome modification using GET cannot satisfy current demand for high-efficiency and site-directed mutagenesis, retrofitting of artificial nucleases has developed into a new avenue within this field. Based on mechanisms to recognize target genes, newly-developed GETs can generally be subdivided into three cleavage systems, protein-dependent DNA cleavage systems (i.e., zinc-finger nucleases, ZFN, and transcription activator-like effector nucleases, TALEN), RNA-dependent DNA cleavage systems (i.e., clustered regularly interspaced short palindromic repeats-CRISPR associated proteins, CRISPR-Cas9, CRISPR-Cpf1, and CRISPR-C2c1), and RNA-dependent RNA cleavage systems (i.e., RNA interference, RNAi, and CRISPR-C2c2). All these techniques can lead to double-stranded (DSB) or single-stranded breaks (SSB), and result in either random mutations via non-homologous end-joining (NHEJ) or targeted mutation via homologous recombination (HR). Thus, site-directed mutagenesis can be induced via targeted gene knock-out, knock-in, or replacement to modify specific characteristics including morphology-modification, resistance-enhancement, and physiological mechanism-improvement along with plant growth and development. In this paper, an non-comprehensive review on the development of different GETs as applied to plants is presented. PMID:28261237

  5. Progress in Genome Editing Technology and Its Application in Plants.

    Science.gov (United States)

    Zhang, Kai; Raboanatahiry, Nadia; Zhu, Bin; Li, Maoteng

    2017-01-01

    Genome editing technology (GET) is a versatile approach that has progressed rapidly as a mechanism to alter the genotype and phenotype of organisms. However, conventional genome modification using GET cannot satisfy current demand for high-efficiency and site-directed mutagenesis, retrofitting of artificial nucleases has developed into a new avenue within this field. Based on mechanisms to recognize target genes, newly-developed GETs can generally be subdivided into three cleavage systems, protein-dependent DNA cleavage systems (i.e., zinc-finger nucleases, ZFN, and transcription activator-like effector nucleases, TALEN), RNA-dependent DNA cleavage systems (i.e., clustered regularly interspaced short palindromic repeats-CRISPR associated proteins, CRISPR-Cas9, CRISPR-Cpf1, and CRISPR-C2c1), and RNA-dependent RNA cleavage systems (i.e., RNA interference, RNAi, and CRISPR-C2c2). All these techniques can lead to double-stranded (DSB) or single-stranded breaks (SSB), and result in either random mutations via non-homologous end-joining (NHEJ) or targeted mutation via homologous recombination (HR). Thus, site-directed mutagenesis can be induced via targeted gene knock-out, knock-in, or replacement to modify specific characteristics including morphology-modification, resistance-enhancement, and physiological mechanism-improvement along with plant growth and development. In this paper, an non-comprehensive review on the development of different GETs as applied to plants is presented.

  6. Transgenic plant cells lacking mitochondrial alternative oxidase have increased susceptibility to mitochondria-dependent and -independent pathways of programmed cell death.

    Science.gov (United States)

    Robson, Christine A; Vanlerberghe, Greg C

    2002-08-01

    The plant mitochondrial electron transport chain is branched such that electrons at ubiquinol can be diverted to oxygen via the alternative oxidase (AOX). This pathway does not contribute to ATP synthesis but can dampen the mitochondrial generation of reactive oxygen species. Here, we establish that transgenic tobacco (Nicotiana tabacum L. cv Petit Havana SR1) cells lacking AOX (AS8 cells) show increased susceptibility to three different death-inducing compounds (H(2)O(2), salicylic acid [SA], and the protein phosphatase inhibitor cantharidin) in comparison with wild-type cells. The timing and extent of AS8 cell death are very similar among the three treatments and, in each case, are accompanied by the accumulation of oligonucleosomal fragments of DNA, indicative of programmed cell death. Death induced by H(2)O(2) or SA occurs by a mitochondria-dependent pathway characterized by cytochrome c release from the mitochondrion. Conversely, death induced by cantharidin occurs by a pathway without any obvious mitochondrial involvement. The ability of AOX to attenuate these death pathways may relate to its ability to maintain mitochondrial function after insult with a death-inducing compound or may relate to its ability to prevent chronic oxidative stress within the mitochondrion. In support of the latter, long-term treatment of AS8 cells with an antioxidant compound increased the resistance of AS8 cells to SA- or cantharidin-induced death. The results indicate that plants maintain both mitochondria-dependent and -independent pathways of programmed cell death and that AOX may act as an important mitochondrial "survival protein" against such death.

  7. Mitochondria Damage and Kidney Disease.

    Science.gov (United States)

    Duann, Pu; Lin, Pei-Hui

    2017-01-01

    The kidney is a vital organ that demands an extraordinary amount of energy to actively maintain the body's metabolism, plasma hemodynamics, electrolytes and water homeostasis, nutrients reabsorption, and hormone secretion. Kidney is only second to the heart in mitochondrial count and oxygen consumption. As such, the health and status of the energy power house, the mitochondria, is pivotal to the health and proper function of the kidney. Mitochondria are heterogeneous and highly dynamic organelles and their functions are subject to complex regulations through modulation of its biogenesis, bioenergetics, dynamics and clearance within cell. Kidney diseases, either acute kidney injury (AKI) or chronic kidney disease (CKD), are important clinical issues and global public health concerns with high mortality rate and socioeconomic burden due to lack of effective therapeutic strategies to cure or retard the progression of the diseases. Mitochondria-targeted therapeutics has become a major focus for modern research with the belief that maintaining mitochondria homeostasis can prevent kidney pathogenesis and disease progression. A better understanding of the cellular and molecular events that govern mitochondria functions in health and disease will potentially lead to improved therapeutics development.

  8. Research Progress in Glycine Betaine Improving Plant Salty Stressful Tolerance

    Institute of Scientific and Technical Information of China (English)

    ZHU Hong; WANG Wenjie; YAN Yongqing; ZU Yuangang

    2008-01-01

    Many plants accumulate compatible solutes in response to the imposition of environmental stresses. Glycine betaine, which is one of compatible solutes in cell of plants, has been shown to have surviving ability for plant from salt stress. Effect of glycine betaine on improving plant salt resistance was discussed in plants under salt stress. The accumulation of glycine betaine protects plants against the damaging effects of stress. Strategies of glycine betaine against the damaging effects of stress were analyzed to clarify the roles of glycine betaine in salt stress tolerance of plants.

  9. [Research progress of genetic engineering on medicinal plants].

    Science.gov (United States)

    Teng, Zhong-qiu; Shen, Ye

    2015-02-01

    The application of genetic engineering technology in modern agriculture shows its outstanding role in dealing with food shortage. Traditional medicinal plant cultivation and collection have also faced with challenges, such as lack of resources, deterioration of environment, germplasm of recession and a series of problems. Genetic engineering can be used to improve the disease resistance, insect resistance, herbicides resistant ability of medicinal plant, also can improve the medicinal plant yield and increase the content of active substances in medicinal plants. Thus, the potent biotechnology can play an important role in protection and large area planting of medicinal plants. In the development of medicinal plant genetic engineering, the safety of transgenic medicinal plants should also be paid attention to. A set of scientific safety evaluation and judgment standard which is suitable for transgenic medicinal plants should be established based on the recognition of the particularity of medicinal plants.

  10. Actin in Mung Bean Mitochondria and Implications for Its Function[W][OA

    Science.gov (United States)

    Lo, Yih-Shan; Cheng, Ning; Hsiao, Lin-June; Annamalai, Arunachalam; Jauh, Guang-Yuh; Wen, Tuan-Nan; Dai, Hwa; Chiang, Kwen-Sheng

    2011-01-01

    Here, a large fraction of plant mitochondrial actin was found to be resistant to protease and high-salt treatments, suggesting it was protected by mitochondrial membranes. A portion of this actin became sensitive to protease or high-salt treatment after removal of the mitochondrial outer membrane, indicating that some actin is located inside the mitochondrial outer membrane. The import of an actin–green fluorescent protein (GFP) fusion protein into the mitochondria in a transgenic plant, actin:GFP, was visualized in living cells and demonstrated by flow cytometry and immunoblot analyses. Polymerized actin was found in mitochondria of actin:GFP plants and in mung bean (Vigna radiata). Notably, actin associated with mitochondria purified from early-developing cotyledons during seed germination was sensitive to high-salt and protease treatments. With cotyledon ageing, mitochondrial actin became more resistant to both treatments. The progressive import of actin into cotyledon mitochondria appeared to occur in concert with the conversion of quiescent mitochondria into active forms during seed germination. The binding of actin to mitochondrial DNA (mtDNA) was demonstrated by liquid chromatography–tandem mass spectrometry analysis. Porin and ADP/ATP carrier proteins were also found in mtDNA-protein complexes. Treatment with an actin depolymerization reagent reduced the mitochondrial membrane potential and triggered the release of cytochrome C. The potential function of mitochondrial actin and a possible actin import pathway are discussed. PMID:21984697

  11. Isolation of Mitochondria from Potato Tubers

    DEFF Research Database (Denmark)

    Havelund, Jesper F.; Salvato, Fernanda; Chen, Mingjie

    2014-01-01

    the in vivo properties of the organelle inside the plant cell. Here, we describe a method to isolate mitochondria from a relatively homogeneous plant tissue, the dormant potato tuber. The homogenization is done using a juice extractor, which is a relatively gentle homogenization procedure where......One way to study the function of plant mitochondria is to extract them from plant tissues in an uncontaminated, intact and functional form. The reductionist assumption is that the components present in such a preparation and the in vitro measurable functions or activities reliably reflect...... the mitochondria are only exposed to strong shearing forces once. After removal of starch and large tissue pieces by filtration, differential centrifugation is used to remove residual starch as well as larger organelles. The crude mitochondria are then first purified by using a step Percoll gradient...

  12. Interaction of plant cell signaling molecules, salicylic acid and jasmonic acid, with the mitochondria of Helicoverpa armigera.

    Science.gov (United States)

    Akbar, S M D; Sharma, H C; Jayalakshmi, S K; Sreeramulu, K

    2012-02-01

    The cotton bollworm, Helicoverpa armigera is a polyphagous pest in Asia, Africa, and the Mediterranean Europe. Salicylic acid (SA) and jasmonic acid (JA) are the cell signaling molecules produced in response to insect attack in plants. The effect of these signaling molecules was investigated on the oxidative phosphorylation and oxidative stress of H. armigera. SA significantly inhibited the state III and state IV respiration, respiratory control index (RCI), respiratory complexes I and II, induced mitochondrial swelling, and cytochrome c release in vitro. Under in vivo conditions, SA induced state IV respiration as well as oxidative stress in time- and dose-dependent manner, and also inhibited the larval growth. In contrast, JA did not affect the mitochondrial respiration and oxidative stress. SA affected the growth and development of H. armigera, in addition to its function as signaling molecules involved in both local defense reactions at feeding sites and the induction of systemic acquired resistance in plants.

  13. Progress and prospects for phosphoric acid fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bonville, L.J.; Scheffler, G.W.; Smith, M.J. [International Fuel Cells Corp., South Windsor, CT (United States)

    1996-12-31

    International Fuel Cells (IFC) has developed the fuel cell power plant as a new, on-site power generation source. IFC`s commercial fuel cell product is the 200-kW PC25{trademark} power plant. To date over 100 PC25 units have been manufactured. Fleet operating time is in excess of one million hours. Individual units of the initial power plant model, the PC25 A, have operated for more than 30,000 hours. The first model {open_quotes}C{close_quotes} power plant has over 10,000 hours of operation. The manufacturing, application and operation of this power plant fleet has established a firm base for design and technology development in terms of a clear understanding of the requirements for power plant reliability and durability. This fleet provides the benchmark against which power plant improvements must be measured.

  14. One fungus, one name promotes progressive plant pathology.

    Science.gov (United States)

    Wingfield, Michael J; De Beer, Z Wilhelm; Slippers, Bernard; Wingfield, Brenda D; Groenewald, Johannes Z; Lombard, Lorenzo; Crous, Pedro W

    2012-08-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms, for which the taxonomy and, in particular, a dual nomenclature system have frustrated and confused practitioners of plant pathology. The emergence of DNA sequencing has revealed cryptic taxa and revolutionized our understanding of relationships in the fungi. The impacts on plant pathology at every level are already immense and will continue to grow rapidly as new DNA sequencing technologies continue to emerge. DNA sequence comparisons, used to resolve a dual nomenclature problem for the first time only 19 years ago, have made it possible to approach a natural classification for the fungi and to abandon the confusing dual nomenclature system. The journey to a one fungus, one name taxonomic reality has been long and arduous, but its time has come. This will inevitably have a positive impact on plant pathology, plant pathologists and future students of this hugely important discipline on which the world depends for food security and plant health in general. This contemporary review highlights the problems of a dual nomenclature, especially its impact on plant pathogenic fungi, and charts the road to a one fungus, one name system that is rapidly drawing near. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.

  15. The Research Progress of Mitochondria and Cell Regulation%线粒体与细胞调控的研究进展

    Institute of Scientific and Technical Information of China (English)

    汤浩(综述); 林春龙(审校)

    2015-01-01

    线粒体是一种细胞器,广泛存在于除红细胞以外的大多数细胞体内,同时也是细胞进行氧化磷酸化、三羧酸循环及氧化呼吸链的主要场所,产生 ATP,提供细胞活动所需能量,同时线粒体也参与细胞代谢的多个环节,如细胞增殖、凋亡等。近年来,线粒体与细胞调控对疾病的发生、发展成为潜在的研究热点。因此,明确线粒体在细胞调控中的作用机制,以便更好地认识及指导对相关性疾病的治疗具有重要意义。%Mitochondria is a cell organelle,which widely exists in the majority of the cells except red blood cells,at the same time,it is an important place for cell to carry out oxidative phosphorylation ,three tri-carboxylic acid cycle and oxidative respiratory chain , producing ATP for the requirement of cell activity , moreover,mitochondria also participates in multiple processes of cell metabolism ,such as cell proliferation, apoptosis,etc.In recent years,the mitochondria and cell regulation on the occurrence of diseases has become a potential research hotspot.Therefore clarifying the mechanism of cell regulation in mitochondria has a great significance for understanding and guiding the treatment of associated diseases.

  16. AtOMA1 Affects the OXPHOS System and Plant Growth in Contrast to Other Newly Identified ATP-Independent Proteases in Arabidopsis Mitochondria.

    Science.gov (United States)

    Migdal, Iwona; Skibior-Blaszczyk, Renata; Heidorn-Czarna, Malgorzata; Kolodziejczak, Marta; Garbiec, Arnold; Janska, Hanna

    2017-01-01

    Compared with yeast, our knowledge on members of the ATP-independent plant mitochondrial proteolytic machinery is rather poor. In the present study, using confocal microscopy and immunoblotting, we proved that homologs of yeast Oma1, Atp23, Imp1, Imp2, and Oct1 proteases are localized in Arabidopsis mitochondria. We characterized these components of the ATP-independent proteolytic system as well as the earlier identified protease, AtICP55, with an emphasis on their significance in plant growth and functionality in the OXPHOS system. A functional complementation assay demonstrated that out of all the analyzed proteases, only AtOMA1 and AtICP55 could substitute for a lack of their yeast counterparts. We did not observe any significant developmental or morphological changes in plants lacking the studied proteases, either under optimal growth conditions or after exposure to stress, with the only exception being retarded root growth in oma1-1, thus implying that the absence of a single mitochondrial ATP-independent protease is not critical for Arabidopsis growth and development. We did not find any evidence indicating a clear functional complementation of the missing protease by any other protease at the transcript or protein level. Studies on the impact of the analyzed proteases on mitochondrial bioenergetic function revealed that out of all the studied mutants, only oma1-1 showed differences in activities and amounts of OXPHOS proteins. Among all the OXPHOS disorders found in oma1-1, the complex V deficiency is distinctive because it is mainly associated with decreased catalytic activity and not correlated with complex abundance, which has been observed in the case of supercomplex I + III2 and complex I deficiencies. Altogether, our study indicates that despite the presence of highly conservative homologs, the mitochondrial ATP-independent proteolytic system is not functionally conserved in plants as compared with yeast. Our findings also highlight the importance of

  17. One fungus, one name promotes progressive plant pathology

    NARCIS (Netherlands)

    Wingfield, M.J.; Beer, de Z.W.; Slippers, B.; Wingfield, B.D.; Groenewald, J.Z.; Lombard, L.; Crous, P.W.

    2012-01-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms,

  18. One fungus, one name promotes progressive plant pathology

    NARCIS (Netherlands)

    Wingfield, M.J.; De Beer, Z.W.; Slippers, B.; Wingfield, B.D.; Groenewald, J.Z.; Lombard, L.; Crous, P.W.

    2011-01-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms,

  19. Host plant resistance to parasitic weeds; recent progress and bottlenecks.

    Science.gov (United States)

    Yoder, John I; Scholes, Julie D

    2010-08-01

    Parasitic witchweeds (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.) directly invade the roots of crop plants connecting to the vascular system and abstracting nutrients and water. As a consequence they cause devastating losses in crop yield. Genetic resistance to parasitic weeds is a highly desirable component of any control strategy. Resistance to parasitic plants can occur at different stages of the parasite lifecycle: before attachment to the host, during penetration of the root or after establishment of vascular connections. New studies are beginning to shed light on the molecular mechanisms and signaling pathways involved in plant-plant resistance. The first resistance gene to Striga, encoding a CC-NBS-LRR Resistance protein (R) has been identified and cloned suggesting that host plants resist attack from parasitic plants using similar surveillance mechanisms as those used against fungal and bacterial pathogens. It is becoming clear that the salicylic acid (SA) signaling pathway plays an important role in resistance to parasitic plants and genes encoding pathogenesis-related (PR) proteins are upregulated in a number of the resistant interactions. New strategies for engineering resistance to parasitic plants are also being explored, including the expression of parasite-specific toxins in host roots and RNAi to silence parasite genes crucial for development.

  20. Research progress on electrical signals in higher plants

    Institute of Scientific and Technical Information of China (English)

    Xiaofei Yan; Zhongyi Wang; Lan Huang; Cheng Wang; Ruifeng Hou; Zhilong Xu; Xiaojun Qiao

    2009-01-01

    This review introduces the characteristics of electrical signals in higher plants and their corresponding physiological significance,and describes in detail the impact of environmental factors (e.g.light and temperature) on the electrical potential of the plants.Also,we evaluate the measurement techniques used for electrical signals in plants,including intracellular measurement,extracellular measurement,measurement of the ion channel based on the patch-clamp technique and on the non-invasive microelectrode vibrating probe technique.We also give a brief review of the applications of these methods for investigating electrical signals in plants.The ionic mechanism of electrical activity in plants is then discussed in terms of environmental response in higher plants,and this is used to provide a theoretical basis for quantitative description of the electrical signals in plants.A model for interpretation of the electrical signal mechanisms in higher plants is discussed,but further experiments are required for the verification of this model.(C) 2009 National Natural Science Foundation of China and Chinese Academy of Sciences.Published by Elsevier Limited and Science in China Press.All rights reserved.

  1. One fungus, one name promotes progressive plant pathology

    NARCIS (Netherlands)

    Wingfield, M.J.; Beer, de Z.W.; Slippers, B.; Wingfield, B.D.; Groenewald, J.Z.; Lombard, L.; Crous, P.W.

    2012-01-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms,

  2. One fungus, one name promotes progressive plant pathology

    NARCIS (Netherlands)

    Wingfield, M.J.; De Beer, Z.W.; Slippers, B.; Wingfield, B.D.; Groenewald, J.Z.; Lombard, L.; Crous, P.W.

    2011-01-01

    The robust and reliable identification of fungi underpins virtually every element of plant pathology, from disease diagnosis to studies of biology, management/control, quarantine and, even more recently, comparative genomics. Most plant diseases are caused by fungi, typically pleomorphic organisms,

  3. [Mechanisms of inhibition of viral replication in plants]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-09-01

    Progress is described concerning genetic mapping CMV movement genes for CMV coat protein in squash and ToMV gene in tomato. These gene products appear to be involved in resistance to squash and tomato mosaic viruses respectively.

  4. Research progress of Tunisian medicinal plants used for acute diabetes

    Institute of Scientific and Technical Information of China (English)

    Wissem Aidi Wannes; Brahim Marzouk

    2016-01-01

    The use of the medicinal plants in treating diabetes is frequent in Africa, especially in Tunisia, and it is ritually transmitted from generation to generation within cultures. Many of Tunisian medicinal plants have been experimentally validated. A comprehensive re-view was conducted to pile up information from scientific journal articles, including indigenous knowledge researches, about Tunisian medicinal plants used for the treatment of diabetes. The aim of this review article is to provide the reader with information concerning the importance of Tunisian medicinal plants in the treatment of diabetes and to draw attention of the health professionals and scientists working in the field of phar-macology and therapeutics to develop new drug formulations to cure different kinds of diabetes.

  5. Research progress of Tunisian medicinal plants used for acute diabetes

    Directory of Open Access Journals (Sweden)

    Wissem Aidi Wannes

    2016-09-01

    Full Text Available The use of the medicinal plants in treating diabetes is frequent in Africa, especially in Tunisia, and it is ritually transmitted from generation to generation within cultures. Many of Tunisian medicinal plants have been experimentally validated. A comprehensive review was conducted to pile up information from scientific journal articles, including indigenous knowledge researches, about Tunisian medicinal plants used for the treatment of diabetes. The aim of this review article is to provide the reader with information concerning the importance of Tunisian medicinal plants in the treatment of diabetes and to draw attention of the health professionals and scientists working in the field of pharmacology and therapeutics to develop new drug formulations to cure different kinds of diabetes.

  6. Progress in Research of Bacteria Fertilizer Strengthening Resistance of Plants

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Bacteria fertilizer is used most widely among all kinds of microbial fertilizers. We summarize the research headway of bacteria fertilizer. It mainly focuses on bacteria fertilizer improving the stress resistance of plant. Then we can offer basis to research and exploit bacteria fertilizer. These bacteria include azotobacter, photosynthetic bacteria, Bacillus mucilaginosus siliceous, phosphorus bacteria, plant growth-promoting rhizobacteria(PGPR), effective microorganism(EM).

  7. Calcium Transport by Corn Mitochondria 1

    Science.gov (United States)

    Silva, Marco Aurelio P.; Carnieri, Eva G. S.; Vercesi, Anibal E.

    1992-01-01

    Mitochondria from some plant tissues possess the ability to take up Ca2+ by a phosphate-dependent mechanism associated with a decrease in membrane potential, H+ extrusion, and increase in the rate of respiration (AE Vercesi, L Pereira da Silva, IS Martins, CF Bernardes, EGS Carnieri, MM Fagian [1989] In G Fiskum, ed, Cell Calcium Metabolism. Plenum Press, New York, pp 103-111). The present study reexamined the nature of the phosphate requirement in this process. The main observations are: (a) Respiration-coupled Ca2+ uptake by isolated corn (Zea mays var Maya Normal) mitochondria or carbonyl cyanide p-trifluoromethoxyphenylhydrazone-induced efflux of the cation from such mitochondria are sensitive to mersalyl and cannot be dissociated from the silmultaneous movement of phosphate in the same direction. (b) Ruthenium red-induced efflux is not affected by mersalyl and can occur in the absence of phosphate movement. (c) In Ca2+-loaded corn mitochondria, mersalyl causes net Ca2+ release unrelated to a decrease in membrane potential, probably due to an inhibition of Ca2+ cycling at the level of the influx pathway. It is concluded that corn mitochondria (and probably other plant mitochondria) do possess an electrophoretic influx pathway that appears to be a mersalyl-sensitive Ca2+/inorganic phosphate-symporter and a phosphate-independent efflux pathway possibly similar to the Na2+-independent Ca2+ efflux mechanism of vertebrate mitochondria, because it is not stimulated by Na+. PMID:16668661

  8. 76 FR 78702 - Progress Energy Florida, Inc. (Combined License Application for Levy County Nuclear Power Plant...

    Science.gov (United States)

    2011-12-19

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Progress Energy Florida, Inc. (Combined License Application for Levy County Nuclear Power Plant...) and 2.321(b), the Atomic Safety and Licensing Board (Board) in the above-captioned Progress Energy...

  9. Plant cyclopeptide RA-V kills human breast cancer cells by inducing mitochondria-mediated apoptosis through blocking PDK1–AKT interaction

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Xian-Ying; Chen, Wei [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China); Fan, Jun-Ting [State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming (China); Song, Ran; Wang, Lu [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China); Gu, Yan-Hong [Department of Clinical Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing (China); Zeng, Guang-Zhi [State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming (China); Shen, Yan; Wu, Xue-Feng [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China); Tan, Ning-Hua, E-mail: nhtan@mail.kib.ac.cn [State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming (China); Xu, Qiang, E-mail: molpharm@163.com [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China); Sun, Yang, E-mail: yangsun@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing (China)

    2013-02-15

    In the present paper, we examined the effects of a natural cyclopeptide RA-V on human breast cancer cells and the underlying mechanisms. RA-V significantly inhibited the growth of human breast cancer MCF-7, MDA-MB-231 cells and murine breast cancer 4T1 cells. In addition, RA-V triggered mitochondrial apoptotic pathway which was indicated by the loss of mitochondrial membrane potential, the release of cytochrome c, and the activation of caspase cascade. Further study showed that RA-V dramatically inhibited phosphorylation of AKT and 3-phosphoinositide dependent protein kinase 1 (PDK1) in MCF-7 cells. Moreover, RA-V disrupted the interaction between PDK1 and AKT in MCF-7 cells. Furthermore, RA-V-induced apoptosis could be enhanced by phosphatidylinositol 3-kinase inhibitor or attenuated by over-expression of AKT in all the three kinds of breast cancer cells. Taken together, this study shows that RA-V, which can induce mitochondria-mediated apoptosis, exerts strong anti-tumor activity against human breast cancer. The underlying anti-cancer mechanism of RA-V is related to the blockage of the interaction between PDK1 and AKT. - Highlights: ► Plant cyclopeptide RA-V kills human breast cancer cells. ► RA-V triggered mitochondrial apoptotic pathway in human breast cancer cells. ► RA-V inhibited phosphorylation of AKT and PDK1 in breast cancer MCF-7 cells. ► Its mechanism is related to the blockage of the interaction between PDK1 and AKT.

  10. Review. Elimination of viruses in plants: twenty years of progress

    Directory of Open Access Journals (Sweden)

    A. Panattoni

    2013-02-01

    Full Text Available To shed light on trends about elimination of viruses from plants, a bibliographic research was conducted to identify thermotherapy, chemotherapy and tissue culture trials published from 1991 through 2010. Among woody plants, grapevine, apple and peach are the most frequent targets of sanitation protocols because their health status is strictly regulated. Even if thermotherapy represents the preferred method for the host, grapevine viruses can also be eliminated with chemotherapy and tissue culture; apple viruses respond to chemotherapy as well. Although a similar trend was reported among herbaceous plants, chemotherapy was the most frequently used technique in potato. With regard to virus, thermotherapy was successfully applied against viruses belonging to 13 families and an unassigned genus. Instead, chemotherapy and tissue culture techniques eradicated viruses belonging to fewer families (nine. An interpretation of thermotherapy effects considers the new metabolic “pathways” triggered by the natural antiviral response emitted by the infected plant, with particular reference to virus-induced gene silencing. With regard to chemotherapy, several groups of antiviral drugs belong to inosine monophosphate dehydrogenase inhibitors, S-adenosylhomocysteine hydrolase inhibitors, neuraminidase inhibitors. Tissue culture, usually adopted to regenerate plantlets in biotechnological breeding programs, represents the less used tool for eliminate viruses from plants.

  11. Progress in Genome Editing Technology and Its Application in Plants

    OpenAIRE

    Zhang, Kai; Raboanatahiry, Nadia; Zhu, Bin; Li, Maoteng

    2017-01-01

    Genome editing technology (GET) is a versatile approach that has progressed rapidly as a mechanism to alter the genotype and phenotype of organisms. However, conventional genome modification using GET cannot satisfy current demand for high-efficiency and site-directed mutagenesis, retrofitting of artificial nucleases has developed into a new avenue within this field. Based on mechanisms to recognize target genes, newly-developed GETs can generally be subdivided into three cleavage systems, pr...

  12. AtCOX10, a protein involved in haem o synthesis during cytochrome c oxidase biogenesis, is essential for plant embryogenesis and modulates the progression of senescence.

    Science.gov (United States)

    Mansilla, Natanael; Garcia, Lucila; Gonzalez, Daniel H; Welchen, Elina

    2015-11-01

    Cytochrome c oxidase (CcO) biogenesis requires several accessory proteins implicated, among other processes, in copper and haem a insertion. In yeast, the farnesyltransferase Cox10p that catalyses the conversion of haem b to haem o is the limiting factor in haem a biosynthesis and is essential for haem a insertion in CcO. In this work, we characterized AtCOX10, a putative Cox10p homologue from Arabidopsis thaliana. AtCOX10 was localized in mitochondria and was able to restore growth of a yeast Δcox10 null mutant on non-fermentable carbon sources, suggesting that it also participates in haem o synthesis. Plants with T-DNA insertions in the coding region of both copies of AtCOX10 could not be recovered, and heterozygous mutant plants showed seeds with embryos arrested at early developmental stages that lacked CcO activity. Heterozygous mutant plants exhibited lower levels of CcO activity and cyanide-sensitive respiration but normal levels of total respiration at the expense of an increase in alternative respiration. AtCOX10 seems to be implicated in the onset and progression of senescence, since heterozygous mutant plants showed a faster decrease in chlorophyll content and photosynthetic performance than wild-type plants after natural and dark-induced senescence. Furthermore, complementation of mutants by expressing AtCOX10 under its own promoter allowed us to obtain plants with T-DNA insertions in both AtCOX10 copies, which showed phenotypic characteristics comparable to those of wild type. Our results highlight the relevance of haem o synthesis in plants and suggest that this process is a limiting factor that influences CcO activity levels, mitochondrial respiration, and plant senescence.

  13. Isolation of Mitochondria from Potato Tubers

    DEFF Research Database (Denmark)

    Havelund, Jesper F.; Salvato, Fernanda; Chen, Mingjie;

    2014-01-01

    the in vivo properties of the organelle inside the plant cell. Here, we describe a method to isolate mitochondria from a relatively homogeneous plant tissue, the dormant potato tuber. The homogenization is done using a juice extractor, which is a relatively gentle homogenization procedure where...

  14. Molecular Strategies for Targeting Antioxidants to Mitochondria: Therapeutic Implications

    Science.gov (United States)

    2015-01-01

    Abstract Mitochondrial function and specifically its implication in cellular redox/oxidative balance is fundamental in controlling the life and death of cells, and has been implicated in a wide range of human pathologies. In this context, mitochondrial therapeutics, particularly those involving mitochondria-targeted antioxidants, have attracted increasing interest as potentially effective therapies for several human diseases. For the past 10 years, great progress has been made in the development and functional testing of molecules that specifically target mitochondria, and there has been special focus on compounds with antioxidant properties. In this review, we will discuss several such strategies, including molecules conjugated with lipophilic cations (e.g., triphenylphosphonium) or rhodamine, conjugates of plant alkaloids, amino-acid- and peptide-based compounds, and liposomes. This area has several major challenges that need to be confronted. Apart from antioxidants and other redox active molecules, current research aims at developing compounds that are capable of modulating other mitochondria-controlled processes, such as apoptosis and autophagy. Multiple chemically different molecular strategies have been developed as delivery tools that offer broad opportunities for mitochondrial manipulation. Additional studies, and particularly in vivo approaches under physiologically relevant conditions, are necessary to confirm the clinical usefulness of these molecules. Antioxid. Redox Signal. 22, 686–729. PMID:25546574

  15. Mechanisms of mitochondria and autophagy crosstalk.

    Science.gov (United States)

    Rambold, Angelika S; Lippincott-Schwartz, Jennifer

    2011-12-01

    Autophagy is a cellular survival pathway that recycles intracellular components to compensate for nutrient depletion and ensures the appropriate degradation of organelles. Mitochondrial number and health are regulated by mitophagy, a process by which excessive or damaged mitochondria are subjected to autophagic degradation. Autophagy is thus a key determinant for mitochondrial health and proper cell function. Mitophagic malfunction has been recently proposed to contribute to progressive neuronal loss in Parkinson's disease. In addition to autophagy's significance in mitochondrial integrity, several lines of evidence suggest that mitochondria can also substantially influence the autophagic process. The mitochondria's ability to influence and be influenced by autophagy places both elements (mitochondria and autophagy) in a unique position where defects in one or the other system could increase the risk to various metabolic and autophagic related diseases.

  16. 50 years of medicinal plant research - every progress in methodology is a progress in science.

    Science.gov (United States)

    Phillipson, J David

    2003-06-01

    Many scientific methods of analysis have been developed for the investigation of the constituents and biological activities of medicinal plants during the 50 years since the inaugural meeting of the Gesellschaft für Arzneipflanzenforschung (GA). The chromatographic (e. g., TLC, GLC, HPLC), spectroscopic (e. g., UV, IR, 1H- and 13C-NMR, MS), and biological (e. g., anticancer, anti-inflammatory, immunostimulant, antiprotozoal, CNS) techniques utilized for medicinal plant research are briefly reviewed. The contribution that advances in scientific methodology have made to our understanding of the actions of some herbal medicines (e. g., Echinacea, Ginkgo, St John's wort, Cannabis), as well as to ethnopharmacology and biotechnology, are briefly summarized. Plants have provided many medicinal drugs in the past and remain as a potential source of novel therapeutic agents. Despite all of the powerful analytical techniques available, the majority of plant species has not been investigated chemically or biologically in any great detail and even well known medicinal plants require further clinical study.

  17. A plant-specific cyclin-dependent kinase is involved in the control of G2/M progression in plants.

    Science.gov (United States)

    Porceddu, A; Stals, H; Reichheld, J P; Segers, G; De Veylder, L; Barroco, R P; Casteels, P; Van Montagu, M; Inzé, D; Mironov, V

    2001-09-28

    Cyclin-dependent kinases (CDKs) control the key transitions in the eukaryotic cell cycle. All the CDKs known to control G(2)/M progression in yeast and animals are distinguished by the characteristic PSTAIRE motif in their cyclin-binding domain and are closely related. Higher plants contain in addition a number of more divergent non-PSTAIRE CDKs with still obscure functions. We show that a plant-specific type of non-PSTAIRE CDKs is involved in the control of the G(2)/M progression. In synchronized tobacco BY-2 cells, the corresponding protein, accumulated in a cell cycle-regulated fashion, peaking at the G(2)/M transition. The associated histone H1 kinase activity reached a maximum in mitosis and required a yet unidentified subunit to be fully active. Down-regulation of the associated kinase activity in transgenic tobacco plants using a dominant-negative mutation delayed G(2)/M transition. These results provide the first evidence that non-PSTAIRE CDKs are involved in the control of the G(2)/M progression in plants.

  18. Instrumentation and process control for fossil demonstration plants. Quarterly technical progress report, January--March 1977

    Energy Technology Data Exchange (ETDEWEB)

    LeSage, L.G.; O' Fallon, N.M.

    1977-09-01

    Progress during the quarter of January through March 1977 on ANL 189a 49622R2, Instrumentation and Process Control for Fossil Demonstration Plants (FDP) is reported. Work has been performed on updating the study of the state-of-the-art of instrumentation for Fossil Demonstration Plants (FDP), on development of mass-flow and other on-line instruments for FDP, process control analysis for FDP, and organization of a symposium on instrumentation and control for FDP. Progress in these areas is described.

  19. Research Progress and Perspectives of Nitrogen Fixing Bacterium, Gluconacetobacter diazotrophicus, in Monocot Plants

    Directory of Open Access Journals (Sweden)

    N. Eskin

    2014-01-01

    Full Text Available Gluconacetobacter diazotrophicus is a nitrogen fixing bacterium originally found in monocotyledon sugarcane plants in which the bacterium actively fixes atmosphere nitrogen and provides significant amounts of nitrogen to plants. This bacterium mainly colonizes intercellular spaces within the roots and stems of plants and does not require the formation of the complex root organ like nodule. The bacterium is less plant/crop specific and indeed G. diazotrophicus has been found in a number of unrelated plant species. Importantly, as the bacterium was of monocot plant origin, there exists a possibility that the nitrogen fixation feature of the bacterium may be used in many other monocot crops. This paper reviews and updates the research progress of G. diazotrophicus for the past 25 years but focuses on the recent research development.

  20. [Mechanisms of potassium transport in plants and fungi]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Slayman, C.L.

    1993-07-01

    Progress is reported on three front namely survey of ion channels in Arabidopsis; chemical characterization of the tonoplast cation channel (YVC1) in Saccharomyces; and characterization of a fungal proton pump cloned into mammalian cells. Continued work with the yeast plasma-membrane K{sup +} channel (YPK1) led to clear demonstrations that gating of YPK1 depends upon the disequilibrium voltage for K{sup +}, rather than upon the absolute membrane voltage, and that all channels observable in the yeast plasmalemma are unchanged in primary pump mutants. Preliminary patch-clamp studies on the plasmalemma of Neurospora also identified two conspicuous cation channels in that membrane. A concerted effort to measure cytoplasmic pH in Saccharomyces and Neurospora by means of fluorescent pH indicators evinced two important findings that dyes taken up in (lipophilic) heavily esterified forms accumulate in vacuoles, not in the cytosol; and that the size and distribution of fungal vacuoles can be manipulated dramatically by altering carbon metabolism.

  1. Genetic improvement of biofuel plants: recent progress and patents.

    Science.gov (United States)

    Johnson, T Sudhakar; Badri, Jyothi; Sastry, R Kalpana; Shrivastava, Anshul; Kishor, P B Kavi; Sujatha, M

    2013-04-01

    Due to depleting reserves of fossil fuels, political uncertainties, increase in demand of energy needs and growing concerns of environmental effects, bioenergy as an alternative source of energy needs had taken centre stage globally. In this report, we review the progress made in lignocellulose, cellulose and fermentation based biofuels in addition to tree borne oil seeds. Algae as a source of feedstock for the biofuel has also been reviewed. Recent efforts in genome sequencing of biofuel crops and molecular breeding approaches have increased our understanding towards crop improvement of major feedstocks. Besides, patenting trends in bioenergy sector were assessed by patent landscape analysis. The results showed an increasing trend in published patents during the last decade which is maximum during 2011. A conceptual framework of "transgenesis in biofuels to industrial application" was developed based on the patent analytics viz., International Patent Classification (IPC) analysis and Theme Maps. A detailed claim analysis based on the conceptual framework assessed the patenting trends that provided an exhaustive dimension of the technology. The study emphasizes the current thrust in bioenergy sector by various public and private institutions to expedite the process of biofuel production.

  2. [Progress in research and application of gene engineering on medicinal plants].

    Science.gov (United States)

    Wang, Min; Huang, Lu-qi; Li, Meng-meng

    2008-06-01

    China is the country possessing the largest amount of trade and consumption of medicinal plants in the world. Research and application of gene engineering on medicinal plants are the one of the most promising ways to increase the productivity and quality of medicinal plants, reduce the resource stress, and enhance the competitive power and sustainable development ability of the medicinal plants industry. In spite of the great progress in research and application of plant gene engineering worldwide, the research of gene transformation has mostly been conducted on some model plants, and the application of transgenic plant has been limited to a few staple and important crop species. For medicinal plants, recently the researches of gene transformation has emerged, however, compared with other crop and economic plants, it is still a very limited amount. On the basis of a general introduction of application of transgenic plants, this paper focuses on the present situation of the research and application of gene engineering on medicinal plants, to put forward the problems in this field, and give a prospect for its development.

  3. Control of triacylglycerol biosynthesis in plants. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-31

    Seeds of most species of the Umbelliferae (Apiaciae), Araliaceae, and Garryaceae families are characterized by their high content of the unusual C{sub 18} monounsaturated fatty acid petroselinic acid (18:l{Delta}{sup 6cis}). Prior to a recent report of this lab, little was known of the biosynthetic origin of the cis{Delta}{sup 6} double bond of petroselinic acid. Such knowledge may be of both biochemical and biotechnological significance. Because petroselinic acid is potentially the product of a novel desaturase, information regarding its synthesis may contribute to an understanding of fatty acid desaturation mechanisms in plants. Through chemical cleavage at its double bond, petroselinic acid can be used as a precursor of lauric acid (12:0), a component of detergents and surfactants, and adipic acid (6:0 dicarboxylic), the monomeric component of nylon 6,6. Therefore, the development of an agronomic source of an oil rich in petroselinic acid is of biotechnological interest. As such, studies of petroselinic acid biosynthesis may provide basic information required for any attempt to genetically engineer the production and accumulation of this fatty acid in an existing oilseed.

  4. Research progress of genome editing and derivative technologies in plants.

    Science.gov (United States)

    Qiwei, Shan; Caixia, Gao

    2015-10-01

    Genome editing technologies using engineered nucleases have been widely used in many model organisms. Genome editing with sequence-specific nuclease (SSN) creates DNA double-strand breaks (DSBs) in the genomic target sites that are primarily repaired by the non-homologous end joining (NHEJ) or homologous recombination (HR) pathways, which can be employed to achieve targeted genome modifications such as gene mutations, insertions, replacements or chromosome rearrangements. There are three major SSNs─zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN) and clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) system. In contrast to ZFN and TALEN, which require substantial protein engineering to each DNA target, the CRISPR/Cas9 system requires only a change in the guide RNA. For this reason, the CRISPR/Cas9 system is a simple, inexpensive and versatile tool for genome engineering. Furthermore, a modified version of the CRISPR/Cas9 system has been developed to recruit heterologous domains that can regulate endogenous gene expression, such as activation, depression and epigenetic regulation. In this review, we summarize the development and applications of genome editing technologies for basic research and biotechnology, as well as highlight challenges and future directions, with particular emphasis on plants.

  5. Chemistry research and development. Progress report, December 1978-May 1979. [Component, pilot plant, instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Miner, F. J.

    1980-06-30

    Progress and activities are reported on component development, pilot plant development, and instrumentation and statistical systems. Specific items studied include processing of pond sludge, transport of radioactive materials and wastes, corrosion, decontamination and cleaning, fluidized-bed incineration, Pu contamination of soils, chemical analysis, radiometric analysis, security. (DLC)

  6. Clearing of invasive alien plants in South Africa: a preliminary assessment of costs and progress

    CSIR Research Space (South Africa)

    Marais, R

    2004-01-01

    Full Text Available This paper provides estimates of the costs of clearing important species of invasive alien plants, as well as of progress made with clearing, based on data from a recently developed GIS-based project information system. Before the deployment...

  7. Research progress on isolation and cloning of functional genes in tea plants

    Institute of Scientific and Technical Information of China (English)

    MA Chunlei; CHEN Liang

    2007-01-01

    Tea,which has many sanitarian functions,is one of the most popular non-alcoholic soft and healthy beverages in the world.In many countries,as well as in China,tea (Camellia sinensis) is an important cash crop.It has great value as a source of secondary metabolic products.Molecular biology of tea plants has been one of the most active and kinetic research fields of tea science for the last decade.Isolation and cloning of important functional genes of tea plants have a critical significance on elucidating the molecular mechanism of high quality,yield and resistance,as well as genetic manipulating via biotechnological approaches for tea plants.In this paper,we introduced the research progress on the isolation and cloning of functional genes in tea plants.In addition,the brief prospect on the research of functional genes of tea plants in the near future is also given out.

  8. Progress and challenges in using stable isotopes to trace plant carbon and water relations across scales

    Directory of Open Access Journals (Sweden)

    C. Werner

    2012-08-01

    Full Text Available Stable isotope analysis is a powerful tool for assessing plant carbon and water relations and their impact on biogeochemical processes at different scales. Our process-based understanding of stable isotope signals, as well as technological developments, has progressed significantly, opening new frontiers in ecological and interdisciplinary research. This has promoted the broad utilisation of carbon, oxygen and hydrogen isotope applications to gain insight into plant carbon and water cycling and their interaction with the atmosphere and pedosphere. Here, we highlight specific areas of recent progress and new research challenges in plant carbon and water relations, using selected examples covering scales from the leaf to the regional scale. Further, we discuss strengths and limitations of recent technological developments and approaches and highlight new opportunities arising from unprecedented temporal and spatial resolution of stable isotope measurements.

  9. Light-dependent intracellular positioning of mitochondria in Arabidopsis thaliana mesophyll cells.

    Science.gov (United States)

    Islam, Md Sayeedul; Niwa, Yasuo; Takagi, Shingo

    2009-06-01

    Mitochondria, the power house of the cell, are one of the most dynamic cell organelles. Although there are several reports on actin- or microtubule-dependent movement of mitochondria in plant cells, intracellular positioning and motility of mitochondria under different light conditions remain open questions. Mitochondria were visualized in living Arabidopsis thaliana leaf cells using green fluorescent protein fused to a mitochondrion-targeting signal. In darkness, mitochondria were distributed randomly in palisade cells. In contrast, mitochondria accumulated along the periclinal walls, similar to the accumulation response of chloroplasts, when treated with weak blue light (470 nm, 4 micromol m(-2) s(-1)). Under strong blue light (100 micromol m(-2) s(-1)), mitochondria occupied the anticlinal positions similar to the avoidance response of chloroplasts and nuclei. While strong red light (660 nm, 100 micromol m(-2) s(-1)) induced the accumulation of mitochondria along the inner periclinal walls, green light exhibited little effect on the distribution of mitochondria. In addition, the mode of movement of individual mitochondria along the outer periclinal walls under different light conditions was precisely analyzed by time-lapse fluorescence microscopy. A gradual increase in the number of static mitochondria located in the vicinity of chloroplasts with a time period of blue light illumination clearly demonstrated the accumulation response of mitochondria. Light-induced co-localization of mitochondria with chloroplasts strongly suggested their mutual metabolic interactions. This is the first characterization of the light-dependent redistribution of mitochondria in plant cells.

  10. 植物线粒体遗传的研究进展%Research progress of mitochondrial inheritance in plant

    Institute of Scientific and Technical Information of China (English)

    崔彬彬; 朱维红; 张妍; 蓝岚

    2011-01-01

    对植物线粒体遗传方式、遗传机理的最新进展进行了综述。被子植物线粒体的遗传方式以单亲母系遗传占绝对的统治地位,在裸子植物中,不同的种差别较大,松科、红豆杉科线粒体多为母系遗传,而南洋杉科、杉科、柏科和三尖杉科的线粒体主要为父系遗传方式。绝大数植物线粒体遗传有其不同于质体遗传的特征,线粒体在雄性生殖细胞中持续存在,甚至参与受精进入合子,但又更多地表现为母系遗传。%Genetic pattern and genetic mechanisms of plant mitochondrias were summarized in the paper. Trie single maternal inheritance was the absolute dominance of the mitochondrial genetic manners of angiosperm. In gymnosperm, the different species vary greatly, the mitochondrias of most species of Knaceae.Taxaceae were maternal inheritance, and the mitochondrias of most species of Araucariaceae, Taxodiaceae, Cupressaceae and Cephalotaxaceae were paternal inheritance. The most plant mitochonrias had their different genetic characteristics of plasmid inheritance. Mitochondria in the male germ cells per-sistly existed and even participated in the fertilization process and entered into the zygote and showed maternal inheritace.

  11. Mitochondria and Organismal Longevity

    OpenAIRE

    2012-01-01

    Mitochondria are essential for various biological processes including cellular energy production. The oxidative stress theory of aging proposes that mitochondria play key roles in aging by generating reactive oxygen species (ROS), which indiscriminately damage macromolecules and lead to an age-dependent decline in biological function. However, recent studies show that increased levels of ROS or inhibition of mitochondrial function can actually delay aging and increase lifespan. The aim of thi...

  12. Characterization of DNA-binding proteins from pea mitochondria

    DEFF Research Database (Denmark)

    Hatzack, F.A.; Dombrowski, S.; Brennicke, A.

    1998-01-01

    We studied transcription initiation in the mitochondria of higher plants, with particular respect to promoter structures. Conserved elements of these promoters have been successfully identified by in vitro transcription systems in different species, whereas the involved protein components are still...

  13. 2010 GORDON RESEARCH CONFERENCE ON MITOCHONDRIA & CHLOROPLASTS, LUCCA, ITALY, JULY 11-16, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Alice Barkan

    2010-07-16

    The 2010 GRC on Mitochondria & Chloroplasts will assemble an international group of molecular, structural and cellular biologists, biochemists and geneticists investigating a broad spectrum of fundamental problems related to the biology of these organelles in animal, plant and fungal cells. This field has witnessed an extraordinary expansion in recent years, fueled by the discovery of the role of mitochondria in human disease and ageing, and of the synergy of chloroplasts and mitochondria in energetic output, the identification of novel factors involved in organelle division, movement, signaling and acclimation to changing environmental conditions, and by the powerful tools of organelle proteomics. The 2010 GRC will highlight advances in the elucidation of molecular mechanisms of organelle biogenesis including regulation of genome structure, evolution and expression, organellar protein import, assembly and turnover of respiratory and photosynthetic complexes, bidirectional signaling between organelles and nucleus, organelle morphology and dynamics, and the integration of cellular metabolism. We will also explore progress in mechanisms of disease and ageing/ senescence in animals and plants. The organellar field has forged new fronts toward a global and comprehensive understanding of mitochondrial and chloroplast biology at the molecular level. Many of the molecules under study in model organisms are responsible for human diseases, providing significant impetus for a meeting that encourages interactions between mammalian, fungal and plant organellar biologists.

  14. Light-induced import of the chromoprotein, phytochrome, into mitochondria

    Science.gov (United States)

    Serlin, B. S.; Roux, S. J.

    1986-01-01

    Mitochondria extracted from plants that were irradiated with actinic light in vivo have associated with them the chromoprotein, phytochrome. This phytochrome retains its native subunit size of 124 kDa after proteolytic treatment of the mitochondria with trypsin and chymotrypsin. This result suggests that phytochrome is not exposed on the outer surface of the outer mitochondrial membrane. Phytochrome, so protected, is not found to be associated with mitochondria derived from unirradiated plants. The possibility that the photoactivation of phytochrome induces a conformational change in its structure which facilitates its transport into the mitochondrion is discussed.

  15. Progress Towards an Interdisciplinary Science of Plant Phenology: Building Predictions Across Space, Time and Species Diversity

    Science.gov (United States)

    Wolkovich, Elizabeth M.; Cook, Benjamin I.; Davies, T. Jonathan

    2013-01-01

    Climate change has brought renewed interest in the study of plant phenology - the timing of life history events. Data on shifting phenologies with warming have accumulated rapidly, yet research has been comparatively slow to explain the diversity of phenological responses observed across latitudes, growing seasons and species. Here, we outline recent efforts to synthesize perspectives on plant phenology across the fields of ecology, climate science and evolution. We highlight three major axes that vary among these disciplines: relative focus on abiotic versus biotic drivers of phenology, on plastic versus genetic drivers of intraspecific variation, and on cross-species versus autecological approaches. Recent interdisciplinary efforts, building on data covering diverse species and climate space, have found a greater role of temperature in controlling phenology at higher latitudes and for early-flowering species in temperate systems. These efforts have also made progress in understanding the tremendous diversity of responses across species by incorporating evolutionary relatedness, and linking phenological flexibility to invasions and plant performance. Future research with a focus on data collection in areas outside the temperate mid-latitudes and across species' ranges, alongside better integration of how risk and investment shape plant phenology, offers promise for further progress.

  16. An intrinsic microRNA timer regulates progressive decline in shoot regenerative capacity in plants.

    Science.gov (United States)

    Zhang, Tian-Qi; Lian, Heng; Tang, Hongbo; Dolezal, Karel; Zhou, Chuan-Miao; Yu, Sha; Chen, Juan-Hua; Chen, Qi; Liu, Hongtao; Ljung, Karin; Wang, Jia-Wei

    2015-02-01

    Plant cells are totipotent and competent to regenerate from differentiated organs. It has been shown that two phytohormones, auxin and cytokinin, play critical roles within this process. As in animals, the regenerative capacity declines with age in plants, but the molecular basis for this phenomenon remains elusive. Here, we demonstrate that an age-regulated microRNA, miR156, regulates shoot regenerative capacity. As a plant ages, the gradual increase in miR156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors leads to the progressive decline in shoot regenerative capacity. In old plants, SPL reduces shoot regenerative capacity by attenuating the cytokinin response through binding with the B-type ARABIDOPSIS RESPONSE REGULATORs, which encode the transcriptional activators in the cytokinin signaling pathway. Consistently, the increased amount of exogenous cytokinin complements the reduced shoot regenerative capacity in old plants. Therefore, the recruitment of age cues in response to cytokinin contributes to shoot regenerative competence. © 2015 American Society of Plant Biologists. All rights reserved.

  17. Improving human reliability through better nuclear power plant system design. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Golay, M.W.

    1995-01-10

    The project on {open_quotes}Development of a Theory of the Dependence of Human Reliability upon System Designs as a Means of Improving Nuclear Power Plant Performance{close_quotes} has been undertaken in order to address the important problem of human error in advanced nuclear power plant designs. Most of the creativity in formulating such concepts has focused upon improving the mechanical reliability of safety related plant systems. However, the lack of a mature theory has retarded similar progress in reducing the likely frequencies of human errors. The main design mechanism used to address this class of concerns has been to reduce or eliminate the human role in plant operations and accident response. The plan of work being pursued in this project is to perform a set of experiments involving human subject who are required to operate, diagnose and respond to changes in computer-simulated systems, relevant to those encountered in nuclear power plants. In the tests the systems are made to differ in complexity in a systematic manner. The computer program used to present the problems to be solved also records the response of the operator as it unfolds. Ultimately this computer is also to be used in compiling the results of the project. The work of this project is focused upon nuclear power plant applications. However, the persuasiveness of human errors in using all sorts of electromechanical machines gives it a much greater potential importance. Because of this we are attempting to pursue our work in a fashion permitting broad generalizations.

  18. On Cellular Darwinism: Mitochondria.

    Science.gov (United States)

    Bull, Larry

    2016-01-01

    The significant role of mitochondria within cells is becoming increasingly clear. This letter uses the NKCS model of coupled fitness landscapes to explore aspects of organelle-nucleus coevolution. The phenomenon of mitochondrial diversity is allowed to emerge under a simple intracellular evolutionary process, including varying the relative rate of evolution by the organelle. It is shown how the conditions for the maintenance of more than one genetic variant of mitochondria are similar to those previously suggested as needed for the original symbiotic origins of the relationship using the NKCS model.

  19. "Respirasome"-like supercomplexes in green leaf mitochondria of spinach.

    Science.gov (United States)

    Krause, Frank; Reifschneider, Nicole H; Vocke, Dirk; Seelert, Holger; Rexroth, Sascha; Dencher, Norbert A

    2004-11-12

    Higher plant mitochondria have many unique features compared with their animal and fungal counterparts. This is to a large extent related to the close functional interdependence of mitochondria and chloroplasts, in which the two ATP-generating processes of oxidative phosphorylation and photosynthesis, respectively, take place. We show that digitonin treatment of mitochondria contaminated with chloroplasts from spinach (Spinacia oleracea) green leaves at two different buffer conditions, performed to solubilize oxidative phosphorylation supercomplexes, selectively extracts the mitochondrial membrane protein complexes and only low amounts of stroma thylakoid membrane proteins. By analysis of digitonin extracts from partially purified mitochondria of green leaves from spinach using blue and colorless native electrophoresis, we demonstrate for the first time that in green plant tissue a substantial proportion of the respiratory complex IV is assembled with complexes I and III into "respirasome"-like supercomplexes, previously observed in mammalian, fungal, and non-green plant mitochondria only. Thus, fundamental features of the supramolecular organization of the standard respiratory complexes I, III, and IV as a respirasome are conserved in all higher eukaryotes. Because the plant respiratory chain is highly branched possessing additional alternative enzymes, the functional implications of the occurrence of respiratory supercomplexes in plant mitochondria are discussed.

  20. Research progress of plant population genomics based on high-throughput sequencing.

    Science.gov (United States)

    Yunsheng, Wang

    2016-08-01

    Population genomics, a new paradigm for population genetics, combine the concepts and techniques of genomics with the theoretical system of population genetics and improve our understanding of microevolution through identification of site-specific effect and genome-wide effects using genome-wide polymorphic sites genotypeing. With the appearance and improvement of the next generation high-throughput sequencing technology, the numbers of plant species with complete genome sequences increased rapidly and large scale resequencing has also been carried out in recent years. Parallel sequencing has also been done in some plant species without complete genome sequences. These studies have greatly promoted the development of population genomics and deepened our understanding of the genetic diversity, level of linking disequilibium, selection effect, demographical history and molecular mechanism of complex traits of relevant plant population at a genomic level. In this review, I briely introduced the concept and research methods of population genomics and summarized the research progress of plant population genomics based on high-throughput sequencing. I also discussed the prospect as well as existing problems of plant population genomics in order to provide references for related studies.

  1. Redox interplay between mitochondria and peroxisomes

    Directory of Open Access Journals (Sweden)

    Celien eLismont

    2015-05-01

    Full Text Available Reduction-oxidation or ‘redox’ reactions are an integral part of a broad range of cellular processes such as gene expression, energy metabolism, protein import and folding, and autophagy. As many of these processes are intimately linked with cell fate decisions, transient or chronic changes in cellular redox equilibrium are likely to contribute to the initiation and progression of a plethora of human diseases. Since a long time, it is known that mitochondria are major players in redox regulation and signaling. More recently, it has become clear that also peroxisomes have the capacity to impact redox-linked physiological processes. To serve this function, peroxisomes cooperate with other organelles, including mitochondria. This review provides a comprehensive picture of what is currently known about the redox interplay between mitochondria and peroxisomes in mammals. We first outline the pro- and antioxidant systems of both organelles and how they may function as redox signaling nodes. Next, we critically review and discuss emerging evidence that peroxisomes and mitochondria share an intricate redox-sensitive relationship and cooperate in cell fate decisions. Key issues include possible physiological roles, messengers, and mechanisms. We also provide examples of how data mining of publicly-available datasets from ‘omics’ technologies can be a powerful means to gain additional insights into potential redox signaling pathways between peroxisomes and mitochondria. Finally, we highlight the need for more studies that seek to clarify the mechanisms of how mitochondria may act as dynamic receivers, integrators, and transmitters of peroxisome-derived mediators of oxidative stress. The outcome of such studies may open up exciting new avenues for the community of researchers working on cellular responses to organelle-derived oxidative stress, a research field in which the role of peroxisomes is currently highly underestimated and an issue of

  2. Progress in Aluminum Electrolysis Control and Future Direction for Smart Aluminum Electrolysis Plant

    Science.gov (United States)

    Zhang, Hongliang; Li, Tianshuang; Li, Jie; Yang, Shuai; Zou, Zhong

    2016-10-01

    The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and highly corrosive conditions. However, these conditions have restricted the measurement of key control parameters, making the control of aluminum reduction cells a difficult problem in the industry. Because aluminum electrolysis control systems have a significant economic influence, substantial research has been conducted on control algorithms, control systems and information systems for aluminum reduction cells. This article first summarizes the development of control systems and then focuses on the progress made since 2000, including alumina concentration control, temperature control and electrolyte molecular ratio control, fault diagnosis, cell condition prediction and control system expansion. Based on these studies, the concept of a smart aluminum electrolysis plant is proposed. The frame construction, key problems and current progress are introduced. Finally, several future directions are discussed.

  3. Mechanisms of mitochondria and autophagy crosstalk

    OpenAIRE

    Rambold, Angelika S; Lippincott-Schwartz, Jennifer

    2011-01-01

    Autophagy is a cellular survival pathway that recycles intracellular components to compensate for nutrient depletion and ensures the appropriate degradation of organelles. Mitochondrial number and health are regulated by mitophagy, a process by which excessive or damaged mitochondria are subjected to autophagic degradation. Autophagy is thus a key determinant for mitochondrial health and proper cell function. Mitophagic malfunction has been recently proposed to contribute to progressive neuro...

  4. Artificial Mitochondria Transfer: Current Challenges, Advances, and Future Applications

    Directory of Open Access Journals (Sweden)

    Andrés Caicedo

    2017-01-01

    Full Text Available The objective of this review is to outline existing artificial mitochondria transfer techniques and to describe the future steps necessary to develop new therapeutic applications in medicine. Inspired by the symbiotic origin of mitochondria and by the cell’s capacity to transfer these organelles to damaged neighbors, many researchers have developed procedures to artificially transfer mitochondria from one cell to another. The techniques currently in use today range from simple coincubations of isolated mitochondria and recipient cells to the use of physical approaches to induce integration. These methods mimic natural mitochondria transfer. In order to use mitochondrial transfer in medicine, we must answer key questions about how to replicate aspects of natural transport processes to improve current artificial transfer methods. Another priority is to determine the optimum quantity and cell/tissue source of the mitochondria in order to induce cell reprogramming or tissue repair, in both in vitro and in vivo applications. Additionally, it is important that the field explores how artificial mitochondria transfer techniques can be used to treat different diseases and how to navigate the ethical issues in such procedures. Without a doubt, mitochondria are more than mere cell power plants, as we continue to discover their potential to be used in medicine.

  5. Qualitative and quantitative modifications of root mitochondria during senescence of above-ground parts of Arabidopis thaliana.

    Science.gov (United States)

    Fanello, Diego Darío; Bartoli, Carlos Guillermo; Guiamet, Juan José

    2017-05-01

    This work studied modifications experienced by root mitochondria during whole plant senescence or under light deprivation, using Arabidopsis thaliana plants with YFP tagged to mitochondria. During post-bolting development, root respiratory activity started to decline after aboveground organs (i.e., rosette leaves) had senesced. This suggests that carbohydrate starvation may induce root senescence. Similarly, darkening the whole plant induced a decrease in respiration of roots. This was partially due to a decrease in the number of total mitochondria (YFP-labelled mitochondria) and most probably to a decrease in the quantity of mitochondria with a developed inner membrane potential (ΔΨm, i.e., Mitotracker red- labelled mitochondria). Also, the lower amount of mitochondria with ΔΨm compared to YFP-labelled mitochondria at 10d of whole darkened plant, suggests the presence of mitochondria in a "standby state". The experiments also suggest that small mitochondria made the main contribution to the respiratory activity that was lost during root senescence. Sugar supplementation partially restored the respiration of mitochondria after 10d of whole plant dark treatment. These results suggest that root senescence is triggered by carbohydrate starvation, with loss of ΔΨm mitochondria and changes in mitochondrial size distribution. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Medicinally important secondary metabolites in recombinant microorganisms or plants: progress in alkaloid biosynthesis.

    Science.gov (United States)

    Schäfer, Holger; Wink, Michael

    2009-12-01

    Plants produce a high diversity of natural products or secondary metabolites which are important for the communication of plants with other organisms. A prominent function is the protection against herbivores and/or microbial pathogens. Some natural products are also involved in defence against abiotic stress, e.g. UV-B exposure. Many of the secondary metabolites have interesting biological properties and quite a number are of medicinal importance. Because the production of the valuable natural products, such as the anticancer drugs paclitaxel, vinblastine or camptothecin in plants is a costly process, biotechnological alternatives to produce these alkaloids more economically become increasingly important. This review provides an overview of the state of art to produce alkaloids in recombinant microorganisms, such as bacteria or yeast. Some progress has been made in metabolic engineering usually employing a single recombinant alkaloid gene. More importantly, for benzylisoquinoline, monoterpene indole and diterpene alkaloids (taxanes) as well as some terpenoids and phenolics the proof of concept for production of complex alkaloids in recombinant Escherichia coli and yeast has already been achieved. In a long-term perspective, it will probably be possible to generate gene cassettes for complete pathways, which could then be used for production of valuable natural products in bioreactors or for metabolic engineering of crop plants. This will improve their resistance against herbivores and/or microbial pathogens.

  7. Transcellular degradation of axonal mitochondria.

    Science.gov (United States)

    Davis, Chung-ha O; Kim, Keun-Young; Bushong, Eric A; Mills, Elizabeth A; Boassa, Daniela; Shih, Tiffany; Kinebuchi, Mira; Phan, Sebastien; Zhou, Yi; Bihlmeyer, Nathan A; Nguyen, Judy V; Jin, Yunju; Ellisman, Mark H; Marsh-Armstrong, Nicholas

    2014-07-01

    It is generally accepted that healthy cells degrade their own mitochondria. Here, we report that retinal ganglion cell axons of WT mice shed mitochondria at the optic nerve head (ONH), and that these mitochondria are internalized and degraded by adjacent astrocytes. EM demonstrates that mitochondria are shed through formation of large protrusions that originate from otherwise healthy axons. A virally introduced tandem fluorophore protein reporter of acidified mitochondria reveals that acidified axonal mitochondria originating from the retinal ganglion cell are associated with lysosomes within columns of astrocytes in the ONH. According to this reporter, a greater proportion of retinal ganglion cell mitochondria are degraded at the ONH than in the ganglion cell soma. Consistently, analyses of degrading DNA reveal extensive mtDNA degradation within the optic nerve astrocytes, some of which comes from retinal ganglion cell axons. Together, these results demonstrate that surprisingly large proportions of retinal ganglion cell axonal mitochondria are normally degraded by the astrocytes of the ONH. This transcellular degradation of mitochondria, or transmitophagy, likely occurs elsewhere in the CNS, because structurally similar accumulations of degrading mitochondria are also found along neurites in superficial layers of the cerebral cortex. Thus, the general assumption that neurons or other cells necessarily degrade their own mitochondria should be reconsidered.

  8. Noninvasive radiofrequency treatment effect on mitochondria in pancreatic cancer cells.

    Science.gov (United States)

    Curley, Steven A; Palalon, Flavio; Lu, Xiaolin; Koshkina, Nadezhda V

    2014-11-01

    The development of novel therapeutic approaches for cancer therapy is important, especially for tumors that have poor response or develop resistance to standard chemotherapy and radiation. We discovered that noninvasive radiofrequency (RF) fields can affect cancer cells but not normal cells, inhibit progression of tumors in mice, and enhance the anticancer effects of chemotherapy. However, it remains unclear what physiological and molecular mechanisms this treatment induces inside cells. Here, we studied the effect of RF treatment on mitochondria in human pancreatic cancer cells. The morphology of mitochondria in cells was studied via electron microscopy. The alteration of mitochondrial membrane potential (Δψ) was accessed using a Mitotracker probe. The respiratory activity of mitochondria was evaluated by analyzing changes in oxygen consumption rates determined with a Mito Stress Test Kit. The production of intracellular reactive oxygen species was performed using flow cytometry. The colocalization of mitochondria and autophagosome markers in cells was performed using fluorescence immunostaining and confocal microscopy analysis. RF fields treatment changed the morphology of mitochondria in cancer cells, altered polarization of the mitochondrial membrane, substantially impaired mitochondrial respiration, and increased reactive oxygen species production, indicating RF-induced stress on the mitochondria. We also observed frequent colocalization of the autophagosome marker LC3B with the mitochondrial marker Tom20 inside cancer cells after RF exposure, indicating the presence of mitochondria in the autophagosomes. This suggests that RF-induced stress can damage mitochondria and induce elimination of damaged organelles via autophagy. RF treatment impaired the function of mitochondria in cancer cells. Therefore, mitochondria can represent one of the targets of the RF treatment. © 2014 American Cancer Society.

  9. Mitochondria and Cardiovascular Aging

    Science.gov (United States)

    Dai, Dao-Fu; Ungvari, Zoltan

    2013-01-01

    Old age is a major risk factor for cardiovascular diseases. Several lines of evidence in experimental animal models have indicated the central role of mitochondria both in lifespan determination and cardiovascular aging. In this article we review the evidence supporting the role of mitochondrial oxidative stress, mitochondrial damage and biogenesis as well as the crosstalk between mitochondria and cellular signaling in cardiac and vascular aging. Intrinsic cardiac aging in the murine model closely recapitulates age-related cardiac changes in humans (left ventricular hypertrophy, fibrosis and diastolic dysfunction), while the phenotype of vascular aging include endothelial dysfunction, reduced vascular elasticity and chronic vascular inflammation. Both cardiac and vascular aging involve neurohormonal signaling (e.g. renin-angiotensin, adrenergic, insulin-IGF1 signaling) and cell-autonomous mechanisms. The potential therapeutic strategies to improve mitochondrial function in aging and cardiovascular diseases are also discussed, with a focus on mitochondrial-targeted antioxidants, calorie restriction, calorie restriction mimetics and exercise training. PMID:22499901

  10. Glutathione and mitochondria

    OpenAIRE

    Vicent eRibas; Carmen eGarcia-Ruiz; Jose C eFernandez-Checa

    2014-01-01

    Glutathione (GSH) is the main non-protein thiol in cells whose functions are dependent on the redox-active thiol of its cysteine moiety that serves as a cofactor for a number of antioxidant and detoxifying enzymes. While synthesized exclusively in the cytosol from its constituent amino acids, GSH is distributed in different compartments, including mitochondria where its concentration in the matrix equals that of the cytosol. This feature and its negative charge at physiological pH imply the e...

  11. Mitochondria and Neuroplasticity

    OpenAIRE

    Aiwu Cheng; Yan Hou; Mattson, Mark P.

    2010-01-01

    The production of neurons from neural progenitor cells, the growth of axons and dendrites and the formation and reorganization of synapses are examples of neuroplasticity. These processes are regulated by cell-autonomous and intercellular (paracrine and endocrine) programs that mediate responses of neural cells to environmental input. Mitochondria are highly mobile and move within and between subcellular compartments involved in neuroplasticity (synaptic terminals, dendrites, cell body and th...

  12. Mitochondria and Cancer

    OpenAIRE

    Zong, Wei-Xing; Rabinowitz, Joshua D.; White, Eileen

    2016-01-01

    Decades ago Otto Warburg observed that cancers ferment glucose in the presence of oxygen, suggesting that defects in mitochondrial respiration may be the underlying cause of cancer. We now know that the genetic events, which drive aberrant cancer cell proliferation, also alter biochemical metabolism including promoting aerobic glycolysis, but do not typically impair mitochondrial function. Mitochondria supply energy, provide building blocks for new cells, and control redox homeostasis, oncoge...

  13. Mitochondria and neuroplasticity

    OpenAIRE

    Cheng, Aiwu; Hou, Yan; Mark P. Mattson

    2010-01-01

    The production of neurons from neural progenitor cells, the growth of axons and dendrites and the formation and reorganization of synapses are examples of neuroplasticity. These processes are regulated by cell-autonomous and intercellular (paracrine and endocrine) programs that mediate responses of neural cells to environmental input. Mitochondria are highly mobile and move within and between subcellular compartments involved in neuroplasticity (synaptic terminals, dendrites, cell body and th...

  14. Environment, safety and Health Progress Assessment of the Rocky Flats Plant

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report documents the result of the US Department of Energy`s (DOE) Environment, Safety and Health (ES&H) Progress Assessment of the DOE Rocky Flats Plant (RFP) in Golden, Colorado. The assessment, which was conducted during the period of May 17 through May 28, 1993, included a selective review of the ES&H management systems and programs of the responsible DOE Headquarters Program Offices (Defense Programs (DP) and Environmental Restoration and Waste Management (EM)), the DOE Rocky Flats Office (RFO), and the site contractor, EG&G Rocky Flats, Inc. (EG&G). Despite the near constant state of flux under which RFP has been required to operate, the Progress Assessment Team has concluded that significant progress has been made in correcting the deficiencies identified in the 1989 Assessment and in responding responsibly to regulations, and DOE directives and guidance that have been issued since that time. The Team concluded that the improvements have been concentrated in the activities associated with plutonium facilities and in regulatory driven programs. Much remains to be done with respect to implementing on a sitewide basis those management systems that anchor an organization`s pursuit of continuous ES&H improvement. Furthermore the Team concluded that the pace of improvement has been constrained by a combination of factors that have limited the site`s ability to manage change in the pursuit of sitewide ES&H excellence.

  15. Progress and challenges of engineering a biophysical carbon dioxide-concentrating mechanism into higher plants.

    Science.gov (United States)

    Rae, Benjamin D; Long, Benedict M; Förster, Britta; Nguyen, Nghiem D; Velanis, Christos N; Atkinson, Nicky; Hee, Wei Yih; Mukherjee, Bratati; Price, G Dean; McCormick, Alistair J

    2017-04-24

    Growth and productivity in important crop plants is limited by the inefficiencies of the C3 photosynthetic pathway. Introducing CO2-concentrating mechanisms (CCMs) into C3 plants could overcome these limitations and lead to increased yields. Many unicellular microautotrophs, such as cyanobacteria and green algae, possess highly efficient biophysical CCMs that increase CO2 concentrations around the primary carboxylase enzyme, Rubisco, to enhance CO2 assimilation rates. Algal and cyanobacterial CCMs utilize distinct molecular components, but share several functional commonalities. Here we outline the recent progress and current challenges of engineering biophysical CCMs into C3 plants. We review the predicted requirements for a functional biophysical CCM based on current knowledge of cyanobacterial and algal CCMs, the molecular engineering tools and research pipelines required to translate our theoretical knowledge into practice, and the current challenges to achieving these goals. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  16. [Progress in predicting animal feed intake of plant secondary compounds by spectral analysis].

    Science.gov (United States)

    Wang, Yuan-Su; Hong, Fu-Zeng; Wang, Kun

    2007-09-01

    Study on feed intake of phytophagic animals is a key issue in promoting animal productivity and conservation of wild life. However, how to accurately predict the feed intake of grazing animal and wild life is a long remaining problem. Under the mechanism of co-evolution, plant produces secondary compounds such as phenolics, terpenoids and nitrogen-containing compounds to avoid or reduce animal herbivorous damage as a defensive strategy, while animal attained detoxification capacity of biotransforming and mineralizing the compounds by microbial activities and reactions such as hydrolysis and reduction. The attributes of feedstuff and the amount of a particular feed consumed by the animal affect directly the urinary excretion of secondary metabolites. Plant secondary compounds and their metabolites can be efficiently extracted, separated and structure-identified by spectroscopic analytic method. Then the feed intake of the animal can be accurately measured or predicted by the inference model of concentration-ratio that is based on the regression of correlating the secondary metabolites to the precursors in plant. Aromatic compounds, an universal occurrence in vascular plants, play an important role in predicting feed intake of ruminants. Progresses have been made all-around about the new method. Intensive studies have found that different species and developing stage of plant have varying kinds and levels of secondary compounds, and the age, gender and type of animal have different capacity of metabolizing the compounds. Increasing concentrations of the compounds in the diet led to a dose-dependent decrease in food intake best described as an exponential decay. Animals that had not previously been exposed to the compounds ate significantly more when first offered food containing the compound than on subsequent days. Advanced spectroscopic analytic method has been developed and widely applied in extraction (e. g. microwave assisted extraction and ultrasonic extraction

  17. Plant plastid engineering.

    Science.gov (United States)

    Wani, Shabir H; Haider, Nadia; Kumar, Hitesh; Singh, N B

    2010-11-01

    Genetic material in plants is distributed into nucleus, plastids and mitochondria. Plastid has a central role of carrying out photosynthesis in plant cells. Plastid transformation is becoming more popular and an alternative to nuclear gene transformation because of various advantages like high protein levels, the feasibility of expressing multiple proteins from polycistronic mRNAs, and gene containment through the lack of pollen transmission. Recently, much progress in plastid engineering has been made. In addition to model plant tobacco, many transplastomic crop plants have been generated which possess higher resistance to biotic and abiotic stresses and molecular pharming. In this mini review, we will discuss the features of the plastid DNA and advantages of plastid transformation. We will also present some examples of transplastomic plants developed so far through plastid engineering, and the various applications of plastid transformation.

  18. Isolation of rat adrenocortical mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Solinas, Paola [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Fujioka, Hisashi [Electron Microscopy Facility, Department of Pharmacology, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Tandler, Bernard [Department of Biological Sciences, School of Dental Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Hoppel, Charles L., E-mail: charles.hoppel@case.edu [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer A method for isolation of adrenocortical mitochondria from the adrenal gland of rats is described. Black-Right-Pointing-Pointer The purified isolated mitochondria show excellent morphological integrity. Black-Right-Pointing-Pointer The properties of oxidative phosphorylation are excellent. Black-Right-Pointing-Pointer The method increases the opportunity of direct analysis of adrenal mitochondria from small animals. -- Abstract: This report describes a relatively simple and reliable method for isolating adrenocortical mitochondria from rats in good, reasonably pure yield. These organelles, which heretofore have been unobtainable in isolated form from small laboratory animals, are now readily accessible. A high degree of mitochondrial purity is shown by the electron micrographs, as well as the structural integrity of each mitochondrion. That these organelles have retained their functional integrity is shown by their high respiratory control ratios. In general, the biochemical performance of these adrenal cortical mitochondria closely mirrors that of typical hepatic or cardiac mitochondria.

  19. Mitochondria, prostate cancer, and biopsy sampling error.

    Science.gov (United States)

    Parr, Ryan L; Mills, John; Harbottle, Andrew; Creed, Jennifer M; Crewdson, Gregory; Reguly, Brian; Guimont, François S

    2013-04-01

    Mitochondria and their associated genome are emerging as sophisticated indicators of prostate cancer biology. Alterations in the mitochondrial genome (mtgenome) have been implicated in cell proliferation, metastatic behavior, androgen independence, as a signal for apoptosis, and as a predictor of biochemical recurrence. Somatic mutation patterns in complete mtgenomes are associated with prostate specific antigen levels (PSA) in prostate cancer patients and a large-scale mtgenome deletion (3.4 kb) is consistent with a prostate "cancerization" field effect. This review will focus on the biological characteristics of mitochondria and their direct clinical application to prostate cancer. Mitochondrial science is currently influencing clinical prostate cancer diagnostics and the rapid progress in this area indicates future, break-through contributions in the general field of oncology.

  20. Recent Progress Using High-throughput Sequencing Technologies in Plant Molecular Breeding

    Institute of Scientific and Technical Information of China (English)

    Qiang Gao; Guidong Yue; Wenqi Li; Junyi Wang; Jiaohui Xu; Ye Yin

    2012-01-01

    High-throughput sequencing is a revolutionary technological innovation in DNA sequencing.This technology has an ultra-low cost per base of sequencing and an overwhelmingly high data output.High-throughput sequencing has brought novel research methods and solutions to the research fields of genomics and post-genomics.Furthermore,this technology is leading to a new molecular breeding revolution that has landmark significance for scientific research and enables us to launch multi-level,multifaceted,and multi-extent studies in the fields of crop genetics,genomics,and crop breeding.In this paper,we review progress in the application of high-throughput sequencing technologies to plant molecular breeding studies.

  1. Instrumentation and process control for fossil demonstration plants. Annual technical progress report, October 1976--September 1977

    Energy Technology Data Exchange (ETDEWEB)

    LeSage, L. G.; O' Fallon, N. M.

    1977-10-01

    Progress on Instrumentation and Process Control for Fossil Demonstration Plants (FDP) is reported. Work has been performed on updating the study of the state-of-the-art of instrumentation for FDP, development of mass-flow and other on-line instruments for FDP, process control analysis for FDP, and organization of a symposium on instrumentation and control for FDP. A Solids/Gas Flow Test Facility (S/GFTF) under construction for instrument development, testing, evaluation, and calibration is described. The development work for several mass-flow and other on-line instruments is described: acoustic flowmeter, capacitive density flowmeter, neutron activation flowmeter, gamma ray correlation flowmeter, optical flowmeter, composition analysis system, and capacitive liquid interface level meter.

  2. Death of mitochondria during programmed cell death of leaf mesophyll cells.

    Science.gov (United States)

    Selga, Tūrs; Selga, Maija; Pāvila, Vineta

    2005-12-01

    The role of plant mitochondria in the programmed cell death (PCD) is widely discussed. However, spectrum and sequence of mitochondrial structural changes during different types of PCD in leaves are poorly described. Pea, cucumber and rye plants were grown under controlled growing conditions. A part of them were sprinkled with ethylene releaser to accelerate cell death. During yellowing the palisade parenchyma mitochondria were attracted to nuclear envelope. Mitochondrial matrix became electron translucent. Mitochondria entered vacuole by invagination of tonoplast and formed multivesicular bodies. Ethephon treatment increased the frequency of sticking of mitochondria to the nuclear envelope or chloroplasts and peroxisomes. Mitochondria divided by different mechanisms and became enclosed in Golgi and ER derived authopagic vacuoles or in the central vacuole. Several fold increase of the diameter of cristae became typical. In all cases mitochondria were attached to nuclear envelope. It can be considered as structural mechanism of promoting of PCD.

  3. Glutathione and Mitochondria

    Directory of Open Access Journals (Sweden)

    Vicent eRibas

    2014-07-01

    Full Text Available Glutathione (GSH is the main nonprotein thiol in cells whose functions are dependent on the redox-active thiol of its cysteine moiety that serves as a cofactor for a number of antioxidant and detoxifying enzymes. While synthesized exclusively in the cytosol from its constituent amino acids, GSH is distributed in different compartments, including mitochondria where its concentration in the matrix equals that of the cytosol. This feature and its negative charge at physiological pH imply the existence of specific carriers to import GSH from the cytosol to the mitochondrial matrix, where it plays a key role in defense against respiration-induced reactive oxygen species and in the detoxification of lipid hydroperoxides and electrophiles. Moreover, as mitochondria play a central strategic role in the activation and mode of cell death, mitochondrial GSH has been shown to critically regulate the level of sensitization to secondary hits that induce mitochondrial membrane permeabilization and release of proteins confined in the intermembrane space that once in the cytosol engage the molecular machinery of cell death. In this review, we summarize recent data on the regulation of mitochondrial GSH and its role in cell death and prevalent human diseases, such as cancer, fatty liver disease and Alzheimer’s disease.

  4. Progress on Plant-Level Components for Nuclear Fuel Recycling: Commonality

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, Valmor F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2011-08-15

    Progress made in developing a common mathematical modeling framework for plant-level components of a simulation toolkit for nuclear fuel recycling is summarized. This ongoing work is performed under the DOE Nuclear Energy Advanced Modeling and Simulation (NEAMS) program which has an element focusing on safeguards and separations (SafeSeps). One goal of this element is to develop a modeling and simulation toolkit for used nuclear fuel recycling. The primary function of the SafeSeps simulation toolkit is to enable the time-dependent coupling of separation modules and safeguards tools (either native or third-party supplied) that simulate and/or monitor the individual separation processes in a separations plant. The toolkit integration environment will offer an interface for the modules to register in the toolkit domain based on the commonality of diverse unit operations. This report discusses the source of this commonality from a combined mathematical modeling and software design perspectives, and it defines the initial basic concepts needed for development of application modules and their integrated form, that is, an application software. A unifying mathematical theory of chemical thermomechanical network transport for physicochemical systems is proposed and outlined as the basis for developing advanced modules. A program for developing this theory from the underlying first-principles continuum thermomechanics will be needed in future developments; accomplishment of this task will enable the development of a modern modeling approach for plant-level models. Rigorous, advanced modeling approaches at the plant-level can only proceed from the development of reduced (or low-order) models based on a solid continuum field theory foundation. Such development will pave the way for future programmatic activities on software verification, simulation validation, and model uncertainty quantification on a scientific basis; currently, no satisfactory foundation exists for

  5. Preparation of Avocado Mitochondria Using Self-Generated Percoll Density Gradients and Changes in Buoyant Density during Ripening.

    Science.gov (United States)

    Moreau, F; Romani, R

    1982-11-01

    Mitochondria from avocado (Persea americana Mill, var. Fuerte and Hass) can be rapidly prepared at every stage of ripening using differential centrifugation and self-generated Percoll gradients. The procedure results in improved oxidative and phosphorylative properties, especially for mitochondria isolated from preclimacteric fruits.A gradual change in the buoyant density of avocado mitochondria takes place during ripening. Climacteric and postclimacteric avocado mitochondria have the same buoyant density as other plant mitochondria (potato, cauliflower), whereas mitochondria from preclimacteric fruit have a lower density. The transition in buoyant density occurs during the climacteric rise, and two populations of intact mitochondria (p = 1.060 and p = 1.075) can be separated at this stage. Evidence indicates that the difference in mitochondrial buoyant density between preclimacteric and postclimacteric mitochondria is likely due to interactions with soluble cytosolic components.

  6. Biochemistry of Mitochondria

    Directory of Open Access Journals (Sweden)

    Filiz Koc

    2003-02-01

    Full Text Available Mitochondria are energy source of cells. They have external and internal membranes, cristas and matrix. External membranes consist of specialized transport proteins. They have monoamine oxidase and citokrome-c reductase which both play role in KREBS cycle as catalyst and many enzymes which are necessary for phospholipid and phosphoric acid synthesis. Enzymes of electron transport chain and oxidative phosphorylation are located in the internal membranes. Also, here, there are transport systems for specific substances, such as ATP, ADP, P1, pyruvate, succinate, malate, citrate, and -ketoglutarate . Matrix; having gel-like consistency, contains a large number of enzymes. [Archives Medical Review Journal 2003; 12(0.100: 1-13

  7. Rhodococcus fascians infection accelerates progression of tobacco BY-2 cells into mitosis through rapid changes in plant gene expression.

    Science.gov (United States)

    Vandeputte, Olivier; Vereecke, Danny; Mol, Adeline; Lenjou, Marc; Van Bockstaele, Dirk; El Jaziri, Mondher; Baucher, Marie

    2007-01-01

    * To characterize plant cell cycle activation following Rhodococcus fascians infection, bacterial impact on cell cycle progression of tobacco BY-2 cells was investigated. * S-phase-synchronized BY-2 cells were cocultivated with R. fascians and cell cycle progression was monitored by measuring mitotic index, cell cycle gene expression and flow cytometry parameters. Cell cycle alteration was further investigated by cDNA-AFLP (amplified fragment length polymorphism). * It was shown that cell cycle progression of BY-2 cells was accelerated only upon infection with bacteria whose virulence gene expression was induced by a leafy gall extract. Thirty-eight BY-2 genes showed a differential expression within 6 h post-infection. Among these, seven were previously associated with specific plant cell cycle phases (in particular S and G2/M phases). Several genes also showed a differential expression during leafy gall formation. * R. fascians-infected BY-2 cells provide a simple model to identify plant genes related to leafy gall development. R. fascians can also be regarded as a useful biotic agent to alter cell cycle progression and, thereby, gain a better understanding of cell cycle regulation in plants.

  8. Identification and characterization of respirasomes in potato mitochondria.

    Science.gov (United States)

    Eubel, Holger; Heinemeyer, Jesco; Braun, Hans-Peter

    2004-04-01

    Plant mitochondria were previously shown to comprise respiratory supercomplexes containing cytochrome c reductase (complex III) and NADH dehydrogenase (complex I) of I(1)III(2) and I(2)III(4) composition. Here we report the discovery of additional supercomplexes in potato (Solanum tuberosum) mitochondria, which are of lower abundance and include cytochrome c oxidase (complex IV). Highly active mitochondria were isolated from potato tubers and stems, solubilized by digitonin, and subsequently analyzed by Blue-native (BN) polyacrylamide gel electrophoresis (PAGE). Visualization of supercomplexes by in-gel activity stains for complex IV revealed five novel supercomplexes of 850, 1,200, 1,850, 2,200, and 3,000 kD in potato tuber mitochondria. These supercomplexes have III(2)IV(1), III(2)IV(2), I(1)III(2)IV(1), I(1)III(2)IV(2), and I(1)III(2)IV(4) compositions as shown by two-dimensional BN/sodium dodecyl sulfate (SDS)-PAGE and BN/BN-PAGE in combination with activity stains for cytochrome c oxidase. Potato stem mitochondria include similar supercomplexes, but complex IV is partially present in a smaller version that lacks the Cox6b protein and possibly other subunits. However, in mitochondria from potato tubers and stems, about 90% of complex IV was present in monomeric form. It was suggested that the I(1)III(2)IV(4) supercomplex represents a basic unit for respiration in mammalian mitochondria termed respirasome. Respirasomes also occur in potato mitochondria but were of low concentrations under all conditions applied. We speculate that respirasomes are more abundant under in vivo conditions.

  9. Transporters Contributing to Iron Trafficking in Plants

    Institute of Scientific and Technical Information of China (English)

    Sarah S. Conte; Elsbeth L. Walker

    2011-01-01

    T This review will discuss recent progress in understanding the many roles of transporters in the whole-plant physiological processes that maintain iron (Fe) homeostasis. These processes include uptake from the soil via roots, control of transport from roots to above-ground parts of the plant, unloading of Fe from the xylem in above-ground parts, loading of Fe into mitochondria and plastids, transport of Fe to reproductive parts of the plant, and Fe mobilization during seed germination. In addition, we will discuss the mechanisms that plants use to cope with an apparently unintended consequence of Fe acquisition: the uptake of toxic heavy metals via Fe transporters. Rapid progress has been made in understanding the transport processes involved in each of these areas in the last 5 years and this review will focus on this recent progress. We will also highlight the key questions regarding transport steps that remain to be elucidated.

  10. Mitochondria in health and disease

    DEFF Research Database (Denmark)

    Durhuus, Jon Ambæk; Madsen, Claus Desler; Rasmussen, Lene Juel

    2015-01-01

    The primary role of mitochondria was long considered to be production of cellular energy. However, as the understanding of mitochondria in disease is ever expanding, so is their additional function for a healthy organism. Mitochondrial dysfunction is linked to a range of pathologies, including...... (SMRM) was titled "Mitochondria in Health and Disease". The conference was organized by Gayathri N, K Thangaraj, and KK Singh and was held at the National Institute of Mental Health & Neuro Sciences (NIMHANS) in Bangalore, India, from the 19th to 20th of December 2013. The meeting featured...

  11. Dissecting the metabolic role of mitochondria during developmental leaf senescence

    NARCIS (Netherlands)

    Chrobok, Daria; Law, Simon R.; Brouwer, Bas; Lindén, Pernilla; Ziolkowska, Agnieszka; Liebsch, Daniela; Narsai, Reena; Szal, Bozena; Moritz, Thomas; Rouhier, Nicolas; Whelan, James; Gardeström, Per; Keech, Olivier

    2016-01-01

    The functions of mitochondria during leaf senescence, a type of programmed cell death aimed at the massive retrieval of nutrients from the senescing organ to the rest of the plant, remain elusive. Here, combining experimental and analytical approaches, we showed that mitochondrial integrity in

  12. Lipids of mitochondria.

    Science.gov (United States)

    Horvath, Susanne E; Daum, Günther

    2013-10-01

    A unique organelle for studying membrane biochemistry is the mitochondrion whose functionality depends on a coordinated supply of proteins and lipids. Mitochondria are capable of synthesizing several lipids autonomously such as phosphatidylglycerol, cardiolipin and in part phosphatidylethanolamine, phosphatidic acid and CDP-diacylglycerol. Other mitochondrial membrane lipids such as phosphatidylcholine, phosphatidylserine, phosphatidylinositol, sterols and sphingolipids have to be imported. The mitochondrial lipid composition, the biosynthesis and the import of mitochondrial lipids as well as the regulation of these processes will be main issues of this review article. Furthermore, interactions of lipids and mitochondrial proteins which are highly important for various mitochondrial processes will be discussed. Malfunction or loss of enzymes involved in mitochondrial phospholipid biosynthesis lead to dysfunction of cell respiration, affect the assembly and stability of the mitochondrial protein import machinery and cause abnormal mitochondrial morphology or even lethality. Molecular aspects of these processes as well as diseases related to defects in the formation of mitochondrial membranes will be described. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Calpains, mitochondria, and apoptosis.

    Science.gov (United States)

    Smith, Matthew A; Schnellmann, Rick G

    2012-10-01

    Mitochondrial activity is critical for efficient function of the cardiovascular system. In response to cardiovascular injury, mitochondrial dysfunction occurs and can lead to apoptosis and necrosis. Calpains are a 15-member family of Ca(2+)-activated cysteine proteases localized to the cytosol and mitochondria, and several have been shown to regulate apoptosis and necrosis. For example, in endothelial cells, Ca(2+) overload causes mitochondrial calpain 1 cleavage of the Na(+)/Ca(2+) exchanger leading to mitochondrial Ca(2+) accumulation. Also, activated calpain 1 cleaves Bid, inducing cytochrome c release and apoptosis. In renal cells, calpains 1 and 2 promote apoptosis and necrosis by cleaving cytoskeletal proteins, which increases plasma membrane permeability and cleavage of caspases. Calpain 10 cleaves electron transport chain proteins, causing decreased mitochondrial respiration and excessive activation, or inhibition of calpain 10 activity induces mitochondrial dysfunction and apoptosis. In cardiomyocytes, calpain 1 activates caspase 3 and poly-ADP ribose polymerase during tumour necrosis factor-α-induced apoptosis, and calpain 1 cleaves apoptosis-inducing factor after Ca(2+) overload. Many of these observations have been elucidated with calpain inhibitors, but most calpain inhibitors are not specific for calpains or a specific calpain family member, creating more questions. The following review will discuss how calpains affect mitochondrial function and apoptosis within the cardiovascular system.

  14. Alternative respiratory path capacity in plant mitochondria: effect of growth temperature, the electrochemical gradient, and assay pH. [Zea mays L. , Vigna radiata L. , Symplocarpus foetidus L. , Sauromatum guttatum Schott

    Energy Technology Data Exchange (ETDEWEB)

    Elthon, T.E.; Stewart, C.R.; McCoy, C.A.; Bonner, W.D. Jr.

    1986-02-01

    Influence of growth temperature on the capacity of the mitochondrial alternative pathway of electron transport was investigated using etiolated corn (Zea mays L.) seedlings. These seedlings were grown to comparable size in either a warm (30/sup 0/C) or a cold (13/sup 0/C) temperature regime, and then their respiration rates were measured as O/sub 2/ uptake at 25/sup 0/C. The capacity of the alternative pathway (KCN-insensitive O/sub 2/ uptake) was found essentially to double in shoots of cold-grown seedlings. When mitochondria were isolated from the shoots a greater potential for flow through the alternative path was observed in mitochondria from the cold-grown seedlings with all substrates used (an average increase of 84%). Using exogenous NADH as the substrate, the effect of the electrochemical gradient on measurable capacities of the cytochrome and alternative pathways was investigated in mitochondria from both etiolated seedlings and thermogenic spadices. In corn shoot and mung bean (Vigna radiata L.) hypocotyl mitochondria increased flow through the cytochrome chain in the absence of the electrochemical gradient was found not to influence the potential for flow through the alternative path. However, in mitochondria from skunk cabbage (Symplocarpus foetidus L.) and voodoo lily (Sauromatum gutatum Schott) spadices increased flow through the cytochrome chain in the absence of the gradient occurred at the expense of flow through the alternative pathway. This experiment also revealed that the potential for respiratory control is largely dependent upon the assay pH.

  15. Targeting of cytosolic mRNA to mitochondria: naked RNA can bind to the mitochondrial surface.

    Science.gov (United States)

    Michaud, Morgane; Maréchal-Drouard, Laurence; Duchêne, Anne-Marie

    2014-05-01

    Mitochondria contain hundreds of proteins but only a few are encoded by the mitochondrial genome. The other proteins are nuclear-encoded and imported into mitochondria. These proteins can be translated on free cytosolic polysomes, then targeted and imported into mitochondria. Nonetheless, numerous cytosolic mRNAs encoding mitochondrial proteins are detected at the surface of mitochondria in yeast, plants and animals. The localization of mRNAs to the vicinity of mitochondria would be a way for mitochondrial protein sorting. The mechanisms responsible for mRNA targeting to mitochondria are not clearly identified. Sequences within the mRNA molecules (cis-elements), as well as a few trans-acting factors, have been shown to be essential for targeting of some mRNAs. In order to identify receptors involved in mRNA docking to the mitochondrial surface, we have developed an in vitro mRNA binding assay with isolated plant mitochondria. We show that naked mRNAs are able to bind to isolated mitochondria, and our results strongly suggest that mRNA docking to the plant mitochondrial outer membrane requires at least one component of TOM complex.

  16. Mitochondria in cardiac hypertrophy and heart failure.

    Science.gov (United States)

    Rosca, Mariana G; Tandler, Bernard; Hoppel, Charles L

    2013-02-01

    Heart failure (HF) frequently is the unfavorable outcome of pathological heart hypertrophy. In contrast to physiological cardiac hypertrophy, which occurs in response to exercise and leads to full adaptation of contractility to the increased wall stress, pathological hypertrophy occurs in response to volume or pressure overload, ultimately leading to contractile dysfunction and HF. Because cardiac hypertrophy impairs the relationship between ATP demand and production, mitochondrial bioenergetics must keep up with the cardiac hypertrophic phenotype. We review data regarding the mitochondrial proteomic and energetic remodeling in cardiac hypertrophy, as well as the temporal and causal relationships between mitochondrial failure to match the increased energy demand and progression to cardiac decompensation. We suggest that the maladaptive effect of sustained neuroendocrine signals on mitochondria leads to bioenergetic fading which contributes to the progression from cardiac hypertrophy to failure. This article is part of a Special Issue entitled "Focus on Cardiac Metabolism". Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Mitochondria in cardiac hypertrophy and heart failure

    Science.gov (United States)

    Rosca, Mariana G.; Tandler, Bernard; Hoppel, Charles L.

    2013-01-01

    Heart failure (HF) frequently is the unfavorable outcome of pathological heart hypertrophy. In contrast to physiological cardiac hypertrophy, which occurs in response to exercise and leads to full adaptation of contractility to the increased wall stress, pathological hypertrophy occurs in response to volume or pressure overload, ultimately leading to contractile dysfunction and HF. Because cardiac hypertrophy impairs the relationship between ATP demand and production, mitochondrial bioenergetics must keep up with the cardiac hypertrophic phenotype. We review data regarding the mitochondrial proteomic and energetic remodeling in cardiac hypertrophy, as well as the temporal and causal relationship between mitochondrial failure to match the increased energy demand and progression to cardiac decompensation. We suggest that the maladaptive effect of sustained neuroendocrine signals on mitochondria leads to bioenergetic fading which contributes to the progression from cardiac hypertrophy to failure. PMID:22982369

  18. Gene introduction into the mitochondria of Arabidopsis thaliana via peptide-based carriers.

    Science.gov (United States)

    Chuah, Jo-Ann; Yoshizumi, Takeshi; Kodama, Yutaka; Numata, Keiji

    2015-01-13

    Available methods in plant genetic transformation are nuclear and plastid transformations because similar procedures have not yet been established for the mitochondria. The double membrane and small size of the organelle, in addition to its large population in cells, are major obstacles in mitochondrial transfection. Here we report the intracellular delivery of exogenous DNA localized to the mitochondria of Arabidopsis thaliana using a combination of mitochondria-targeting peptide and cell-penetrating peptide. Low concentrations of peptides were sufficient to deliver DNA into the mitochondria and expression of imported DNA reached detectable levels within a short incubation period (12 h). We found that electrostatic interaction with the cell membrane is not a critical factor for complex internalization, instead, improved intracellular penetration of mitochondria-targeted complexes significantly enhanced gene transfer efficiency. Our results delineate a simple and effective peptide-based method, as a starting point for the development of more sophisticated plant mitochondrial transfection strategies.

  19. Gene introduction into the mitochondria of Arabidopsis thaliana via peptide-based carriers

    Science.gov (United States)

    Chuah, Jo-Ann; Yoshizumi, Takeshi; Kodama, Yutaka; Numata, Keiji

    2015-01-01

    Available methods in plant genetic transformation are nuclear and plastid transformations because similar procedures have not yet been established for the mitochondria. The double membrane and small size of the organelle, in addition to its large population in cells, are major obstacles in mitochondrial transfection. Here we report the intracellular delivery of exogenous DNA localized to the mitochondria of Arabidopsis thaliana using a combination of mitochondria-targeting peptide and cell-penetrating peptide. Low concentrations of peptides were sufficient to deliver DNA into the mitochondria and expression of imported DNA reached detectable levels within a short incubation period (12 h). We found that electrostatic interaction with the cell membrane is not a critical factor for complex internalization, instead, improved intracellular penetration of mitochondria-targeted complexes significantly enhanced gene transfer efficiency. Our results delineate a simple and effective peptide-based method, as a starting point for the development of more sophisticated plant mitochondrial transfection strategies.

  20. Geothermal commercial power plant study. Monthly progress report, January 29, 1977-February 25, 1977

    Energy Technology Data Exchange (ETDEWEB)

    1977-04-15

    Conceptual designs and capital cost estimates were completed for the six different Heber power plants in this study. The six plants involve two types of operating modes, constant geothermal fluid flow rate and constant power output, each for net capacities of 50, 100, and 200 MWe. Conceptual designs were completed for the six plants by modifying and scaling-up the base case design. The capital costs for all six plants were estimated in fourth-quarter 1976 dollars.

  1. Mitochondria in response to nutrients and nutrient-sensitive pathways.

    Science.gov (United States)

    Baltzer, Claudia; Tiefenböck, Stefanie K; Frei, Christian

    2010-11-01

    Mitochondria are abundant cellular organelles, and are required for the generation of energy through oxidative catabolism. Equally important, mitochondria also provide substrates for de novo synthesis of fatty acids and multiple amino acids. Mitochondrial functions must therefore be tightly linked to cellular nutrient availability. This review focuses on the current knowledge of how nutrients affect mitochondria. In particular, we describe how the transcriptional profile of the nucleus is altered to mediate this control, and the transcription factors that are involved. In addition, we summarize recent progress in our understanding of how transcription-independent mechanisms, most notably through the cellular energy sensor mTOR, are used to adapt mitochondrial functions in respect to cellular metabolic needs.

  2. Research progress of pharmacological activities and analytical methods for plant origin proteins.

    Science.gov (United States)

    Li, Chun-hong; Chen, Cen; Xia, Zhi-ning; Yang, Feng-qing

    2015-07-01

    As one of the important active components of traditional Chinese medicine (TCM), plant origin active proteins have many significant pharmacological functions. According to researches on the plant origin active proteins reported in recent years, pharmacological effects include anti-tumor, immune regulation, anti-oxidant, anti-pathogeny microorganism, anti-thrombus, as well as hypolipidemic and hypoglycemic activities of plant origin were reviewed, respectively. On the other hand, the analytical methods including chromatography, spectroscopy, electrophoresis and mass spectrometry for plant origin proteins analysis were also summarized. The main purpose of this paper is providing a reference for future development and application of plant active proteins.

  3. External NAD(P)H dehydrogenases in Acanthamoeba castellanii mitochondria.

    Science.gov (United States)

    Antos-Krzeminska, Nina; Jarmuszkiewicz, Wieslawa

    2014-09-01

    The mitochondrial respiratory chain of plants and some fungi contains multiple rotenone-insensitive NAD(P)H dehydrogenases, of which at least two are located on the outer surface of the inner membrane (i.e., external NADH and external NADPH dehydrogenases). Annotated sequences of the putative alternative NAD(P)H dehydrogenases of the protozoan Acanthamoeba castellanii demonstrated similarity to plant and fungal sequences. We also studied activity of these dehydrogenases in isolated A. castellanii mitochondria. External NADPH oxidation was observed for the first time in protist mitochondria. The coupling parameters were similar for external NADH oxidation and external NADPH oxidation, indicating similar efficiencies of ATP synthesis. Both external NADH oxidation and external NADPH oxidation had an optimal pH of 6.8 independent of relevant ubiquinol-oxidizing pathways, the cytochrome pathway or a GMP-stimulated alternative oxidase. The maximal oxidizing activity with external NADH was almost double that with external NADPH. However, a lower Michaelis constant (K(M)) value for external NADPH oxidation was observed compared to that for external NADH oxidation. Stimulation by Ca(2+) was approximately 10 times higher for external NADPH oxidation, while NADH dehydrogenase(s) appeared to be slightly dependent on Ca(2+). Our results indicate that external NAD(P)H dehydrogenases similar to those in plant and fungal mitochondria function in mitochondria of A. castellanii.

  4. Ground control to major TOM: mitochondria-nucleus communication.

    Science.gov (United States)

    Eisenberg-Bord, Michal; Schuldiner, Maya

    2017-01-01

    Mitochondria have crucial functions in the cell, including ATP generation, iron-sulfur cluster biogenesis, nucleotide biosynthesis, and amino acid metabolism. All of these functions require tight regulation on mitochondrial activity and homeostasis. As mitochondria biogenesis is controlled by the nucleus and almost all mitochondrial proteins are encoded by nuclear genes, a tight communication network between mitochondria and the nucleus has evolved, which includes signaling cascades, proteins which are dual-localized to the two compartments, and sensing of mitochondrial products by nuclear proteins. All of these enable a crosstalk between mitochondria and the nucleus that allows the 'ground control' to get information on mitochondria's status. Such information facilitates the creation of a cellular balance of mitochondrial status with energetic needs. This communication also allows a transcriptional response in case mitochondrial function is impaired aimed to restore mitochondrial homeostasis. As mitochondrial dysfunction is related to a growing number of genetic diseases as well as neurodegenerative conditions and aging, elucidating the mechanisms governing the mitochondrial/nuclear communication should progress a better understanding of mitochondrial dysfunctions. © 2016 Federation of European Biochemical Societies.

  5. Improving human reliability through better nuclear power plant system design: Program for advanced nuclear power studies. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Golay, M.W.

    1993-10-10

    The project on ``Development of a Theory of the Dependence of Human Reliability upon System Designs as a Means of Improving Nuclear Power Plant Performance`` was been undertaken in order to address the problem of human error in advanced nuclear power plant designs. Lack of a mature theory has retarded progress in reducing likely frequencies of human errors. Work being pursued in this project is to perform a set of experiments involving human subjects who are required to operate, diagnose and respond to changes in computer-simulated systems, relevant to those encountered in nuclear power plants, which are made to differ in complexity in a systematic manner. The computer program used to present the problems to be solved also records the response of the operator as it unfolds.

  6. Mitochondria: isolation, structure and function.

    Science.gov (United States)

    Picard, Martin; Taivassalo, Tanja; Gouspillou, Gilles; Hepple, Russell T

    2011-09-15

    Mitochondria are complex organelles constantly undergoing processes of fusion and fission, processes that not only modulate their morphology, but also their function. Yet the assessment of mitochondrial function in skeletal muscle often involves mechanical isolation of the mitochondria, a process which disrupts their normally heterogeneous branching structure and yields relatively homogeneous spherical organelles. Alternatively, methods have been used where the sarcolemma is permeabilized and mitochondrial morphology is preserved, but both methods face the downside that they remove potential influences of the intracellular milieu on mitochondrial function. Importantly, recent evidence shows that the fragmented mitochondrial morphology resulting from routine mitochondrial isolation procedures used with skeletal muscle alters key indices of function in a manner qualitatively similar to mitochondria undergoing fission in vivo. Although these results warrant caution when interpreting data obtained with mitochondria isolated from skeletal muscle, they also suggest that isolated mitochondrial preparations might present a useful way of interrogating the stress resistance of mitochondria. More importantly, these new findings underscore the empirical value of studying mitochondrial function in minimally disruptive experimental preparations. In this review, we briefly discuss several considerations and hypotheses emerging from this work.

  7. Fungus-Elicited Metabolites from Plants as an Enriched Source for New Leishmanicidal Agents: Antifungal Phenyl-Phenalenone Phytoalexins from the Banana Plant (Musa acuminata) Target Mitochondria of Leishmania donovani Promastigotes

    Science.gov (United States)

    Luque-Ortega, Juan Román; Martínez, Silvia; Saugar, José María; Izquierdo, Laura R.; Abad, Teresa; Luis, Javier G.; Piñero, José; Valladares, Basilio; Rivas, Luis

    2004-01-01

    Two antifungal phenyl-phenalenone phytoalexins isolated from the banana plant (Musa acuminata) elicited with the fungus Fusarium oxysporum, together with a methoxy derivative of one of them and two epoxide precursors of their chemical synthesis, were tested for leishmanicidal activity on Leishmania donovani promastigotes and L. infantum amastigotes. Drugs inhibited proliferation of both forms of the parasite with a 50% lethal concentration range between 10.3 and 68.7 μg/ml. Their lethal mechanism was found linked to the respiratory chain by a systematic approach, including electron microscopy, measurement of the oxygen consumption rate on digitonin-permeabilized promastigotes, and enzymatic assays on a mitochondrial enriched fraction. Whereas the whole set of compounds inhibited the activity of fumarate reductase in the mitochondrial fraction (50% effective concentration [EC50] between 33.3 and 78.8 μg/ml) and on purified enzyme (EC50 = 53.3 to 115 μg/ml), inhibition for succinate dehydrogenase was only observed for the two phytoalexins with the highest leishmanicidal activity: anigorufone and its natural analogue 2-methoxy-9-phenyl-phenalen-1-one (EC50 = 33.5 and 59.6 μg/ml, respectively). These results provided a new structural motif, phenyl-phenalenone, as a new lead for leishmanicidal activity, and support the use of plant extracts enriched in antifungal phytoalexins, synthesized under fungal challenge, as a more rational and effective strategy to screen for new plant leishmanicidal drugs. PMID:15105102

  8. Contradictory Effects of Mitochondria- and Non-mitochondria-targeted Antioxidants on Hepatocarcinogenesis by Altering DNA Repair.

    Science.gov (United States)

    Wang, Bibo; Fu, Jing; Yu, Ting; Xu, An; Qin, Wenhao; Yang, Zhishi; Chen, Yao; Wang, Hongyang

    2017-09-12

    Conflicting effects of antioxidant supplementation on cancer prevention or promotion is of great concern to healthy people and cancer patients. Despite recent studies about antioxidants accelerating the progression of lung cancer and melanoma, it does not fully deny antioxidants for cancer prevention. Both tumor and antioxidants types influence the actual efficacy. However, little is known about the impact of different types of antioxidants on primary hepatocellular carcinoma (HCC), including non-mitochondrial- and mitochondrial-targeted antioxidants. Based on the mouse models of chemical hepatocarcinogenesis, we showed that administration of non-mitochondria-targeted antioxidants N-acetylcysteine (NAC) and the soluble vitamin E analog Trolox prevented tumorigenesis, whereas administration of mitochondria-targeted antioxidants SS-31 (the mitochondria targeted peptide) and Mito-Q (a derivative of ubiquinone) encouraged tumorigenesis. RNA sequencing revealed that NAC and SS-31 cause highly different changes in oxidation-reduction state and DNA damage response. Remarkably, in diethylnitrosamine (DEN)-treated primary hepatocytes, NAC and Trolox alleviated DNA damage by activating ATM/ATR for DNA repair while SS-31 and MitoQ aggravated damage by inactivating them. Interestingly, partial recovery of SS-31-scavengened mitochondrial ROS (mtROS) could alleviate SS-31-aggravated DNA damage. Localization of ATM between mitochondria and nuclei was changed after NAC and SS-31 treatment. Furthermore, blockage of p-ATR led to the recurrence of NAC-ameliorated DEN HCC. In contrast, reactivation of p-ATR blocked SS-31-promoted DEN HCC. These results demonstrate that the type of antioxidants plays a previously unappreciated role in hepatocarcinogenesis, and provide a mechanistic rationale for exploring the therapeutic use of antioxidants for liver cancer. This article is protected by copyright. All rights reserved. © 2017 by the American Association for the Study of Liver Diseases.

  9. Molecular aspects of allergic contact dermatitis to plants. Recent progress in phytodermatochemistry.

    Science.gov (United States)

    Benezra, C; Ducombs, G

    1987-01-01

    A classification of plants based on the chemical structures of their skin sensitizers is presented. A whole range of chemical structures of contact sensitizers exists in plants containing sesquiterpene lactones (Compositae, Frullania, Lauraceae etc.), tulipalin (Tulipa, Alstroemeria etc.), quinones (Primula and tropical woods), long chain phenols (Anacardiaceae, Ginkgoaceae) and miscellaneous structures such as aldehydes, ketones, terpene hydrocarbons etc. Knowledge of allergens in various plants allows prediction of cross-reactivity.

  10. [Research progress of chemistry and anti-cancer activities of natural products from Chinese Garcinia plants].

    Science.gov (United States)

    Fu, Wen-Wei; Tan, Hong-Sheng; Xu, Hong-Xi

    2014-02-01

    Garcinia plants are one of the rich sources of natural xanthones and benzophenones which have attracted a great deal of attention from the scientists in the fields of chemistry and pharmacology. Recently, many structurally unique constituents with various bioactivities, especially anti-tumor activity, have been isolated from Garcinia plants. This concise review focused on the anti-cancer activity natural products isolated from Chinese Garcinia plants, and the research finding by authors and collaborators over the past several years were cited.

  11. Crosstalk between mitochondria and peroxisomes

    Institute of Scientific and Technical Information of China (English)

    Jean; Demarquoy; Fran?oise; Le; Borgne

    2015-01-01

    Mitochondria and peroxisomes are small ubiquitous organelles. They both play major roles in cell metabolism,especially in terms of fatty acid metabolism,reactive oxygen species(ROS) production,and ROS scavenging,and it is now clear that they metabolically interact with each other. These two organelles share some properties,such as great plasticity and high potency to adapt their form and number according to cell requirements. Their functions are connected,and any alteration in the function of mitochondria may induce changes inperoxisomal physiology. The objective of this paper was to highlight the interconnection and the crosstalk existing between mitochondria and peroxisomes. Special emphasis was placed on the best known connections between these organelles:origin,structure,and metabolic interconnections.

  12. Regulation of polyamine synthesis in plants. Final progress report, July 1, 1991--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Malmberg, R.L.

    1995-07-01

    This research focused on unusual post-translational modifications occuring in a arginine decarboxylase cDNA clone in oats. A novel regulatory mechanism for polyamines was explored and an attempt was made to characterize it. A plant ornithine decarboxylase cDNA was identified in Arabidopsis. Further work remains on the mechanisms of polyamine regulation and function in plants.

  13. Conservation and sustainable use of medicinal plants: problems, progress, and prospects.

    Science.gov (United States)

    Chen, Shi-Lin; Yu, Hua; Luo, Hong-Mei; Wu, Qiong; Li, Chun-Fang; Steinmetz, André

    2016-01-01

    Medicinal plants are globally valuable sources of herbal products, and they are disappearing at a high speed. This article reviews global trends, developments and prospects for the strategies and methodologies concerning the conservation and sustainable use of medicinal plant resources to provide a reliable reference for the conservation and sustainable use of medicinal plants. We emphasized that both conservation strategies (e.g. in situ and ex situ conservation and cultivation practices) and resource management (e.g. good agricultural practices and sustainable use solutions) should be adequately taken into account for the sustainable use of medicinal plant resources. We recommend that biotechnical approaches (e.g. tissue culture, micropropagation, synthetic seed technology, and molecular marker-based approaches) should be applied to improve yield and modify the potency of medicinal plants.

  14. [Research progress in chemical communication among insect-resistant genetically modified plants, insect pests and natural enemies].

    Science.gov (United States)

    Liu, Qing-Song; Li, Yun-He; Chen, Xiu-Ping; Peng, Yu-Fa

    2014-08-01

    Semiochemicals released by plants or insects play an important role in the communication among plants, phytophagous insects and their natural enemies. They thus form a chemical information network which regulates intra- and inter-specific behaviors and sustains the composition and structure of plant and insect communities. The application of insect-resistant genetically modified (IRGM) crops may affect the chemical communication within and among the tritrophic levels, and thus cause disturbances to the biotic community structure and the stability of the farmland ecosystem. This has raised concerns about the environmental safety of IRGM crops and triggered research worldwide. In the current article we provided a brief summary of the chemical communication among plants, herbivores and natural enemies; analyzed the potential of IRGM crops to affect the chemical communication between plants and arthropods and the related mechanisms; and discussed the current research progress and the future prospects in this field. We hope that this will promote the research in this field by Chinese scientists and increase our understanding of the potential effects of growing of IRGM crops on the arthropod community structure.

  15. Accelerating progress toward operational excellence of fossil energy plants with CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Zitney, S.; Liese, E.; Mahapatra, P.; Turton, R. Bhattacharyya, D.

    2012-01-01

    To address challenges in attaining operational excellence for clean energy plants, the National Energy Technology Laboratory has launched a world-class facility for Advanced Virtual Energy Simulation Training And Research (AVESTARTM). The AVESTAR Center brings together state-of-the-art, real-time, high-fidelity dynamic simulators with operator training systems and 3D virtual immersive training systems into an integrated energy plant and control room environment. This paper will highlight the AVESTAR Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of an integrated gasification combined cycle power plant (IGCC) with carbon dioxide capture.

  16. Exogenous ether lipids predominantly target mitochondria

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Richter, Doris; Hannibal-Bach, Hans Kristian

    2012-01-01

    Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high......, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria...

  17. [Research progress of the bHLH transcription factors involved in genic male sterility in plants].

    Science.gov (United States)

    Yongming, Liu; Ling, Zhang; Jianyu, Zhou; Moju, Cao

    2015-12-01

    Male sterility exists widely in the spermatophytes. It contributes to the study of plant reproductive development and can be used as an effective tool for hybrid seed production in heterosis utilization. Therefore, the study on male sterility is of great value in both theory and application. As one of the largest transcription factor families in plants, basic helix-loop-helix proteins (bHLHs) play a crucial role in regulating plant growth and development. This paper introduces the mechanism of bHLH regulating stamen development in several important model plants. Furthermore, we discuss the molecular mechanisms of genic male sterility resulting from bHLH dysfunction to provide references for crop breeding and theoretical studies.

  18. Maternal inheritance of mitochondria in Eucalyptus globulus.

    Science.gov (United States)

    Vaillancourt, R E; Petty, A; McKinnon, G E

    2004-01-01

    It is important to verify mitochondrial inheritance in plant species in which mitochondrial DNA (mtDNA) will be used as a source of molecular markers. We used a polymerase chain reaction (PCR)/restriction fragment length polymorphism (RFLP) approach to amplify mitochondrial introns from subunits 1, 4, 5, and 7 of NADH dehydrogenase (nad) and cytochrome oxidase subunit II (cox2) in Eucalyptus globulus. PCR fragments were then either sequenced or cut with restriction enzymes to reveal polymorphism. Sequencing cox2 showed that eucalypts lack the intron between exons 1 and 2. One polymorphism was found in intron 2-3 of nad7 following restriction digests with HphI. Fifty-four F1 progeny from seven families with parents distinguishable in their mitochondrial nad7 were screened to show that mitochondria were maternally inherited in E. globulus. These results constitute the first report of mitochondrial inheritance in the family Myrtaceae.

  19. Research progress on the use of plant allelopathy in agriculture and the physiological and ecological mechanisms of allelopathy

    Directory of Open Access Journals (Sweden)

    Fang eCheng

    2015-11-01

    Full Text Available Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. These biochemicals are known as allelochemicals and have beneficial or detrimental effects on target organisms. Plant allelopathy is one of the modes of interaction between receptor and donor plants and may exert either positive effects (e.g., for agricultural management, such as weed control, crop protection, or crop re-establishment or negative effects (e.g., autotoxicity, soil sickness, or biological invasion. To ensure sustainable agricultural development, it is important to exploit cultivation systems that take advantage of the stimulatory / inhibitory influence of allelopathic plants to regulate plant growth and development and to avoid allelopathic autotoxicity. Allelochemicals can potentially be used as growth regulators, herbicides, insecticides and antimicrobial crop protection products. Here, we reviewed the plant allelopathy management practices applied in agriculture and the underlying allelopathic mechanisms described in the literature. The major points addressed are as follows: (1 Description of management practices related to allelopathy and allelochemicals in agriculture. (2 Discussion of the progress regarding the mode of action of allelochemicals and the physiological mechanisms of allelopathy, consisting of the influence on cell micro- and ultra-structure, cell division and elongation, membrane permeability, oxidative and antioxidant systems, growth regulation systems, respiration, enzyme synthesis and metabolism, photosynthesis, mineral ion uptake, protein and nucleic acid synthesis. (3 Evaluation of the effect of ecological mechanisms exerted by allelopathy on microorganisms and the ecological environment. (4 Discussion of existing problems and proposal for future research directions in this field to provide a useful reference for future studies on

  20. Research Progress on the use of Plant Allelopathy in Agriculture and the Physiological and Ecological Mechanisms of Allelopathy.

    Science.gov (United States)

    Cheng, Fang; Cheng, Zhihui

    2015-01-01

    Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. These biochemicals are known as allelochemicals and have beneficial or detrimental effects on target organisms. Plant allelopathy is one of the modes of interaction between receptor and donor plants and may exert either positive effects (e.g., for agricultural management, such as weed control, crop protection, or crop re-establishment) or negative effects (e.g., autotoxicity, soil sickness, or biological invasion). To ensure sustainable agricultural development, it is important to exploit cultivation systems that take advantage of the stimulatory/inhibitory influence of allelopathic plants to regulate plant growth and development and to avoid allelopathic autotoxicity. Allelochemicals can potentially be used as growth regulators, herbicides, insecticides, and antimicrobial crop protection products. Here, we reviewed the plant allelopathy management practices applied in agriculture and the underlying allelopathic mechanisms described in the literature. The major points addressed are as follows: (1) Description of management practices related to allelopathy and allelochemicals in agriculture. (2) Discussion of the progress regarding the mode of action of allelochemicals and the physiological mechanisms of allelopathy, consisting of the influence on cell micro- and ultra-structure, cell division and elongation, membrane permeability, oxidative and antioxidant systems, growth regulation systems, respiration, enzyme synthesis and metabolism, photosynthesis, mineral ion uptake, protein and nucleic acid synthesis. (3) Evaluation of the effect of ecological mechanisms exerted by allelopathy on microorganisms and the ecological environment. (4) Discussion of existing problems and proposal for future research directions in this field to provide a useful reference for future studies on plant

  1. TMX1 determines cancer cell metabolism as a thiol-based modulator of ER-mitochondria Ca2+ flux.

    Science.gov (United States)

    Raturi, Arun; Gutiérrez, Tomás; Ortiz-Sandoval, Carolina; Ruangkittisakul, Araya; Herrera-Cruz, Maria Sol; Rockley, Jeremy P; Gesson, Kevin; Ourdev, Dimitar; Lou, Phing-How; Lucchinetti, Eliana; Tahbaz, Nasser; Zaugg, Michael; Baksh, Shairaz; Ballanyi, Klaus; Simmen, Thomas

    2016-08-15

    The flux of Ca(2+) from the endoplasmic reticulum (ER) to mitochondria regulates mitochondria metabolism. Within tumor tissue, mitochondria metabolism is frequently repressed, leading to chemotherapy resistance and increased growth of the tumor mass. Therefore, altered ER-mitochondria Ca(2+) flux could be a cancer hallmark, but only a few regulatory proteins of this mechanism are currently known. One candidate is the redox-sensitive oxidoreductase TMX1 that is enriched on the mitochondria-associated membrane (MAM), the site of ER-mitochondria Ca(2+) flux. Our findings demonstrate that cancer cells with low TMX1 exhibit increased ER Ca(2+), accelerated cytosolic Ca(2+) clearance, and reduced Ca(2+) transfer to mitochondria. Thus, low levels of TMX1 reduce ER-mitochondria contacts, shift bioenergetics away from mitochondria, and accelerate tumor growth. For its role in intracellular ER-mitochondria Ca(2+) flux, TMX1 requires its thioredoxin motif and palmitoylation to target to the MAM. As a thiol-based tumor suppressor, TMX1 increases mitochondrial ATP production and apoptosis progression. Copyright © 2016 Raturi et al.

  2. Role of acyl carrier protein isoforms in plant lipid metabolism: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Ohlrogge, J.B.

    1989-01-01

    Previous research from my lab has revealed that several higher plant species have multiple isoforms of acyl carrier protein (ACP) and therefore this trait appears highly conserved among higher plants. This level of conservation suggests that the existence of ACP isoforms is not merely the results of neutral gene duplications. We have developed techniques to examine a wider range of species. Acyl carrier proteins can be labelled very specifically and to high specific activity using H-palmitate and the E. coli enzyme acyl-ACP synthetase. Isoforms were then resolved by western blotting and native PAGE of H-palmitate labelled ACP's. Multiple isoforms of ACP were observed the leaf tissue of the monocots Avena sativa and Hordeum vulgare and dicots including Arabidopsis thallina, Cuphea wrightii, and Brassica napus. Lower vascular plants including the cycad, Dioon edule, Ginkgo biloba, the gymnosperm Pinus, the fern Anernia phyllitidis and Psilotum nudum, the most primitive known extant vascular plant, were also found to have multiple ACP isoforms as were the nonvascular liverwort, Marchantia and moss, Polytrichum. Therefore, the development of ACP isoforms occurred early in evolution. However, the uniellular alge Chlamydomonas and Dunaliella and the photosynthetic cyanobacteria Synechocystis and Agmnellum have only a single elecrophotetic form of ACP. Thus, multiple forms of ACP do not occur in all photosynthetic organisms but may be associated with multicellular plants.

  3. Superoxide and Respiratory Coupling in Mitochondria of Insulin-Deficient Diabetic Rats

    OpenAIRE

    Herlein, Judith A.; Fink, Brian D.; O'Malley, Yunxia; Sivitz, William I.

    2008-01-01

    Mitochondrial reactive oxygen species have been implicated in both diabetic complications and the progression of the underlying diabetic state. However, it is not clear whether mitochondria of diabetic origin are intrinsically altered to generate excess reactive oxygen species independent of the surrounding diabetic milieu. Mitochondria were isolated from gastrocnemius, heart, and liver of 2-wk and 2-month streptozotocin diabetic rats and controls. We rigidly quantified mitochondrial superoxi...

  4. Mitochondria and mitochondria-induced signalling molecules as longevity determinants.

    Science.gov (United States)

    Rose, Giuseppina; Santoro, Aurelia; Salvioli, Stefano

    2017-07-01

    An intense cross talk between mitochondria and nucleus continuously informs the cell about the functional state of these crucial organelles and elicits an effective stress response that strenghtens the cell, promoting its survival. Interestingly, this effect can spread also in a non-cell autonomous fashion to distal tissues by means of soluble factors. This stress response is responsible of a consistent lifespan increase in many animal models, while in humans there is still a lack of knowledge. This review summarises the available data on the involvement of mitochondria in longevity focusing in particular on this signalling activity and the consequent stress response that is elicited, and proposes the idea that, similarly to animal models, humans may benefit from this response in terms of delayed aging and longevity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Plant rhizosphere effects on metal mobilization and transport. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Fan, T.W.M.

    1998-06-01

    'Information on the mechanism of how plants mobilize, uptake, and metabolize metal ions is very limited. Especially deficient is the understanding of these processes involving pollutant metal ions and interactions among these ions. Based on the current knowledge regarding nutrient ions, it is clear that elucidation of rhizospheric processes such as exudation of organic ligands by plant roots and plant metabolism/adaptation involving these biogenic chelators is critically important. A mechanistic insight into these processes will advance knowledge in microbe-plant host interactions and how metal ions are mobilized, immobilized, and sequestered by these interactions. This, in turn, is essential to applications such as phytobioremediation and microbioremediation of metal ion pollution. Root exudation also serves many other important rhizosphere functions including energy supply for microbial degradation of organic pollutants, structuring of microbial community, and the formation of soil humic materials which are considered to be a major sink for both organic and inorganic pollutants. How root exudates function is critically dependent on the chemical nature of exudate components. Therefore, a comprehensive characterization of all major exudate components, regardless of their chemical class, should facilitate the development and implementation of bioremediation for both organic and inorganic pollutants. Therefore, the objectives of this project are: (1) To obtain a comprehensive composition of major organic components in plant root exudates as a function of different metal ions; (2) To examine plant metabolic response(s) to these metal ion treatments, with emphasis on biosynthetic pathways of organic ligands; and (3) To investigate the effect(s) of soil microbial (e.g. mycorrhizae) association on (1) and (2).'

  6. The new research on mitochondria

    Institute of Scientific and Technical Information of China (English)

    JI Yu-bin; ZHANG He; JI Chen-feng; LIU Hong-juan

    2008-01-01

    Apoptosis, also known as programmed cell death, is the removal of damaged body organizations,aging or redundant cells in a suicide, has to maintain the health of the body, the normal development of the nervous system, the immune system to maintain the normal function of such areas is of great significance. The morphological characteristics of apoptosis are the cytoplasm concentrated, condensed nuclear chromatin, DNA fragments of a large-scale, the cell membrane invagination and foam formation of apoptotic bodies. There are two classic apoptosis ways which are generally accepted by majority of the scholars currently: Mitochondrial pathway and Death receptor pathway. Mitochondrial membrane is a two-tier structure surrounded the cystic, between the external cavity and internal cavity which is called the Room, surrounded by the internal cavity known as the mitochondria internal room or mitochondrial matrix. Mitochondria with the functions of control cell survival and death: mitochondria play an important role in physiological such as oxidative phosphorylation, electronic transfer, storage Ca2+, energy metabolism, anti-oxidation activity and so on, to provide the basic energy to the various activities of cell life. Study found that mitochondria contain some of the material is closely related to apoptosis, such as Cyt-C, Smac/Diablo, AIF, Ca2+, ROS and so on. In the signal to stimulate apoptosis, mitochondrial membrane permeability, resulting in a series of key changes, including Cyt-C, Smac/Diablo release, decline of the mitochondrial membrane potential (Δψm), the state of the redox within cells, the intervention of Bcl gene family and so on. Different signal transduction ultimately focuses on the mitochondria to activate or inhibit these incidents, then the corresponding signal transduction to control apoptosis. Therefore, the mitochondria in the incidence of apoptosis play an important role. In recent years, the study confirmed that apoptosis imbalance can cause a

  7. Role of mitochondria in the pathogenesis and treatment of glaucoma

    Institute of Scientific and Technical Information of China (English)

    YANG Xue-jiao; GE Jian; ZHUO Ye-hong

    2013-01-01

    Objective To gain insight into the potential mechanism of mitochondria dysfunction in pathogenesis,progression and therapeutic management of glaucoma.Data sources The data used in this review were mainly published in English from 2000 to present obtained from PubMed.The search terms were "mitochondria","glaucoma" and 'trabecular meshwork" or "retinal ganglion cells".Study selection Articles studying the mitochondria-related pathologic mechanism and treatment of glaucoma were selected and reviewed.Results Mitochondrial dysfunction or injury was demonstrated in different eye tissue of glaucoma.A variety of potential injuries (light,toxic materials,oxidative injury,mechanical stress,aging,etc.) and the inherent DNA defects are deemed to cause mitochondrial structural and functional destruction in trabecular meshwork cells,retinal ganglion cells,etc.of glaucoma.In addition,various new experimental and therapeutic interventions were used to preserve mitochondrial function,which may be useful for protecting against optic nerve degeneration or reducing the death of retinal ganglion cells in glaucoma.Conclusions Mitochondria play an important role in the pathogenesis of glaucoma,various strategies targeting mitochondrial protection might provide a promising way to delay the onset of glaucoma or protect RGCs against glaucomatous damage.

  8. Mitochondria: the cellular hub of the dynamic coordinated network.

    Science.gov (United States)

    Yin, Fei; Cadenas, Enrique

    2015-04-20

    Mitochondria are the powerhouses of the eukaryotic cell. After billions of years of evolution, mitochondria have adaptively integrated into the symbiont. Such integration is not only evidenced by the consolidation of genetic information, that is, the transfer of most mitochondrial genes into the nucleus, but also manifested by the functional recombination by which mitochondria participate seamlessly in various cellular processes. In the past decade, the field of mitochondria biology has been focused on the dynamic and interactive features of these semiautonomous organelles. Aspects of a complex multilayer quality control system coordinating mitochondrial function and environmental changes are being uncovered and refined. This Forum summarizes the recent progress of these critical topics, with a focus on the dynamic quality control of mitochondrial reticulum, including their biogenesis, dynamic remodeling, and degradation, as well as the homeostasis of the mitochondrial proteome. These diverse but interconnected mechanisms are found to be critical in the maintenance of a functional, efficient, and responsive mitochondrial population and could therefore become therapeutic targets in numerous mitochondrion-implicated disorders.

  9. 植物中SAMMtases基因研究进展%Progress of SAM Mtases Gene Study in Plants

    Institute of Scientific and Technical Information of China (English)

    穆红梅; 夏冰; 高俊平; 张秀省; 汪仁; 彭峰; 何树兰

    2012-01-01

    SAM Mtases是从多种植物中分离到的一类S-腺苷-L-甲硫氨酸依赖性氧位甲基转移酶基因,该基因对植物体内木质素、类苯基丙烷、类黄酮类、生物碱和脂肪族化合物等许多次生代谢产物合成有直接的影响,并且在植物抗病、抗紫外线、杀虫、抗菌、植物激素生长和信号调节、植物共生、花粉管伸长和花粉生长等生理过程中起重要作用.该文总结了国内外已经克隆到的SAM Mtases同源基因的分离、分类及其功能,为进一步研究SAM Mtases 基因在植物生理代谢调控中的地位及在植物抗性及药用成分育种上的应用提供参考.%SAMMtases was S-adenosyl-L-methionine dependent Omethyltransferase gene. The gene has a direct effect on plant lignin, class of phenyl propane, flavonoids, alkaloids and aliphatic compounds and many other secondary metabolite syntheses. It involved ir. plant disease resistance,UV resistance,insecticide, antiseptic, plant hormones,growth and signal conditioning,symbionts of plants,pollen tube elongation and pollen growth of plant allelopathy reaction. This review provides an overview on the research progress in separation,classification,and functions of SAM Mtases gene. It is helpful for better understanding of its position in plant physiological and metabolic regulation. We also highlight SAM Mtases gene as a candidate gene for plant resistance and plant secondary metabolism improvement.

  10. Recent progress in polar metabolite quantification in plants using liquid chromatography–mass spectrometry.

    Science.gov (United States)

    Liu, Zhiqian; Rochfort, Simone

    2014-09-01

    Metabolite analysis or metabolomics is an important component of systems biology in the post-genomic era. Although separate liquid chromatography (LC) methods for quantification of the major classes of polar metabolites of plants have been available for decades, a single method that enables simultaneous determination of hundreds of polar metabolites is possible only with gas chromatography–mass spectrometry (GC–MS) techniques. The rapid expansion of new LC stationary phases in the market and the ready access of mass spectrometry in many laboratories provides an excellent opportunity for developing LC–MS based methods for multi-target quantification of polar metabolites. Although various LC–MS methods have been developed over the last 10 years with the aim to quantify one or more classes of polar compounds in different matrices, currently there is no consensus LC–MS method that is widely used in plant metabolomics studies. The most promising methods applicable to plant metabolite analysis will be reviewed in this paper and the major problems encountered highlighted. The aim of this review is to provide plant scientists, with limited to moderate experience in analytical chemistry, with up-to-date and simplified information regarding the current status of polar metabolite analysis using LC–MS techniques.

  11. Recent progress in polar metabolite quantification in plants using liquid chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Zhiqian Liu; Simone Rochfort

    2014-01-01

    Metabolite analysis or metabolomics is an impor-tant component of systems biology in the post-genomic era. Although separate liquid chromatography (LC) methods for quantification of the major classes of polar metabolites of plants have been available for decades, a single method that enables simultaneous determination of hundreds of polar metabolites is possible only with gas chromatography-mass spectrometry (GC-MS) techniques. The rapid expansion of new LC stationary phases in the market and the ready access of mass spectrometry in many laboratories provides an excellent opportunity for developing LC-MS based methods for multi-target quantification of polar metabolites. Although various LC-MS methods have been developed over the last 10 years with the aim to quantify one or more classes of polar compounds in different matrices, currently there is no consensus LC-MS method that is widely used in plant metabolomics studies. The most promising methods applicable to plant metabolite analysis wil be reviewed in this paper and the major problems encountered highlighted. The aim of this review is to provide plant scientists, with limited to moderate experience in analytical chemistry, with up-to-date and simplified information regarding the current status of polar metabolite analysis using LC-MS techniques.

  12. Molecular dissection of the cellular mechanisms involved in nickel hyperaccumulation in plants. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Salt, D.

    1998-06-01

    'Phytoremediation, the use of plants for environmental cleanup of pollutants, including toxic metals, holds the potential to allow the economic restoration of heavy metal and radionuclide contaminated sites. A number of terrestrial plants are known to naturally accumulate high levels of metals in their shoots (1--2% dry weight), and these plants have been termed metal-hyperaccumulators. Clearly, the genetic traits that determine metal-hyperaccumulation offers the potential for the development of practical phytoremediation processes. The long-term objective is to rationally design and generate plants ideally suited for phytoremediation using this unique genetic material. Initially, the strategy will focus on isolating and characterizing the key genetic information needed for expression of the metal-hyperaccumulation phenotype. Recently, histidine has been shown to play a major role in Ni hyperaccumulation. Based on this information the authors propose to investigate, at the molecular level, the role of histidine biosynthesis in Ni hyperaccumulation in Thlaspi goesingense, a Ni hyperaccumulator species.'

  13. Behavior of technetium-99 in soils and plants. Progress report, April 1, 1974--March 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Gast, R.G.; Landa, E.R.; Thorvig, L.J.

    1976-12-01

    Studies described in this report were aimed at establishing the magnitude and mechanisms of /sup 99/Tc sorption by soils and uptake by plants. Results show that /sup 99/Tc was sorbed from solution over a period of two to five weeks by 8 of 11 soils studied. The slow rate of sorption, the lack of sorption by low organic matter soils, the elimination of sorption following sterilization and increased sorption following addition of dextrose all point to a microbial role in the sorption process. However, it has not been established whether this is a direct or indirect role nor is it possible to clearly predict the conditions under which sorption will occur. Results of plant uptake studies show that /sup 99/Tc can be taken up and translocated into the photosynthetic tissue of higher plants with concentrations in seeds being much less than in vegetative tissue. Technetium-99 was also shown to be toxic to plants at low concentrations and evidence suggests that this is a chemically rather than a radiologically induced toxicity. However, this remains to be completely resolved, as well as whether there is a threshold level of /sup 99/Tc required before toxicity occurs.

  14. Delays in nuclear power plant construction. Progress report, September 15, 1976--September 14, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Mason, G.E.; Larew, R.E.

    1977-08-10

    This report identifies barriers to shortening nuclear power plant construction schedules and recommends research efforts that should minimize or eliminate the identified barriers. The identified barriers include: (1) design and construction interfacing problems; (2) problems relating to the selection and use of permanent materials and construction methods; (3) construction coordination and communication problems; and (4) problems associated with manpower availability and productivity;

  15. Research Progress in Plant Metacaspase%植物Metacaspase研究进展

    Institute of Scientific and Technical Information of China (English)

    马聪; 孔维文

    2012-01-01

    The hypersensitive reaction is an important process in plant disease resistance. Similar to apoptosis in animals, it is programmed cell death (PCD) process in plants. Caspases (cysteine-dependent aspartate-specific proteases) play a central role in animal apoptotic pathways. No orthologous proteins of caspases have been found in plants, but a group of proteins with similar structures, termed metacaspases, have been found. In plants, some PCD processes depend on metacaspases, and others do not. We discuss researches into the structure and function of metacaspases. The biological functions of metacaspases and their roles in PCD pathways in plants remain to be explored.%过敏性坏死反应是植物的一种重要的抗病机制,类似于动物细胞凋亡,它是一种程序性细胞死亡(programmed cell death,PCD)过程.目前,已经确定半胱天冬蛋白酶(caspase)在动物PCD过程中起核心作用.在植物中,尚未发现其直系同源蛋白,但是有一类与其结构相似的蛋白酶,称为metacaspase.在植物不同的PCD过程中,有的依赖于metacaspase,而有的则不依赖于该类蛋白酶.目前对metacaspase的结构和功能已有了初步的研究,对其深入的研究则进展缓慢,其具体的生物学功能和在PCD信号路径中的定位有待进一步探索.

  16. Superoxide and respiratory coupling in mitochondria of insulin-deficient diabetic rats.

    Science.gov (United States)

    Herlein, Judith A; Fink, Brian D; O'Malley, Yunxia; Sivitz, William I

    2009-01-01

    Mitochondrial reactive oxygen species have been implicated in both diabetic complications and the progression of the underlying diabetic state. However, it is not clear whether mitochondria of diabetic origin are intrinsically altered to generate excess reactive oxygen species independent of the surrounding diabetic milieu. Mitochondria were isolated from gastrocnemius, heart, and liver of 2-wk and 2-month streptozotocin diabetic rats and controls. We rigidly quantified mitochondrial superoxide, respiration and ATP production, respiratory coupling, the expression of several proteins with antioxidant properties, and the redox state of glutathione. Both fluorescent assessment and electron paramagnetic spectroscopy revealed that superoxide production was unchanged or reduced in the 2-month diabetic mitochondria compared with controls. Kinetic analysis of the proton leak showed that diabetic heart and muscle mitochondria were actually more coupled compared with control despite an approximate 2- to 4-fold increase in uncoupling protein-3 content. Adenine nucleotide translocator type 1 expression was reduced by approximately 50% in diabetic muscle mitochondria. Catalase was significantly up-regulated in muscle and heart tissue and in heart mitochondria, whereas glutathione peroxidase expression was increased in liver mitochondria of diabetic rats. We conclude that gastrocnemius, heart, and liver mitochondria of streptozotocin diabetic rats are not irrevocably altered toward excess superoxide production either by complex I or complex III. Moreover, gastrocnemius and heart mitochondria demonstrate increased, not decreased, respiratory coupling. Mitochondria of insulin-deficient diabetic rats do show signs of adaptation to antecedent oxidative stress manifested as tissue-specific enzyme and uncoupling protein expression but remain remarkably robust with respect to superoxide production.

  17. Getting mitochondria to center stage

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, Gottfried, E-mail: gottfried.schatz@unibas.ch

    2013-05-10

    The question of how eukaryotic cells assemble their mitochondria was long considered to be inaccessible to biochemical investigation. This attitude changed about fifty years ago when the powerful tools of yeast genetics, electron microscopy and molecular biology were brought to bear on this problem. The rising interest in mitochondrial biogenesis thus paralleled and assisted in the birth of modern biology. This brief recollection recounts the days when research on mitochondrial biogenesis was an exotic effort limited to a small group of outsiders.

  18. Three-Dimensional Reconstruction, by TEM Tomography, of the Ultrastructural Modifications Occurring in Cucumis sativus L. Mitochondria under Fe Deficiency.

    Directory of Open Access Journals (Sweden)

    Gianpiero Vigani

    Full Text Available Mitochondria, as recently suggested, might be involved in iron sensing and signalling pathways in plant cells. For a better understanding of the role of these organelles in mediating the Fe deficiency responses in plant cells, it is crucial to provide a full overview of their modifications occurring under Fe-limited conditions. The aim of this work is to characterize the ultrastructural as well as the biochemical changes occurring in leaf mitochondria of cucumber (Cucumis sativus L. plants grown under Fe deficiency.Mitochondrial ultrastructure was investigated by transmission electron microscopy (TEM and electron tomography techniques, which allowed a three-dimensional (3D reconstruction of cellular structures. These analyses reveal that mitochondria isolated from cucumber leaves appear in the cristae junction model conformation and that Fe deficiency strongly alters both the number and the volume of cristae. The ultrastructural changes observed in mitochondria isolated from Fe-deficient leaves reflect a metabolic status characterized by a respiratory chain operating at a lower rate (orthodox-like conformation with respect to mitochondria from control leaves.To our knowledge, this is the first report showing a 3D reconstruction of plant mitochondria. Furthermore, these results suggest that a detailed characterization of the link between changes in the ultrastructure and functionality of mitochondria during different nutritional conditions, can provide a successful approach to understand the role of these organelles in the plant response to Fe deficiency.

  19. Oxidative stress, mitochondrial dysfunction and the mitochondria theory of aging.

    Science.gov (United States)

    Kong, Yahui; Trabucco, Sally E; Zhang, Hong

    2014-01-01

    Aging is characterized by a progressive decline in cellular function, organismal fitness and increased risk of age-associated diseases and death. One potential cause of aging is the progressive accumulation of dysfunctional mitochondria and oxidative damage with age. Considerable efforts have been made in our understanding of the role of mitochondrial dysfunction and oxidative stress in aging and age-associated diseases. This chapter outlines the interplay between oxidative stress and mitochondrial dysfunction, and discusses their impact on senescence, cell death, stem cell function, age-associated diseases and longevity.

  20. Mitochondria, synaptic plasticity, and schizophrenia.

    Science.gov (United States)

    Ben-Shachar, Dorit; Laifenfeld, Daphna

    2004-01-01

    The conceptualization of schizophrenia as a disorder of connectivity, i.e., of neuronal?synaptic plasticity, suggests abnormal synaptic modeling and neuronal signaling, possibly as a consequence of flawed interactions with the environment, as at least a secondary mechanism underlying the pathophysiology of this disorder. Indeed, deficits in episodic memory and malfunction of hippocampal circuitry, as well as anomalies of axonal sprouting and synapse formation, are all suggestive of diminished neuronal plasticity in schizophrenia. Evidence supports a dysfunction of mitochondria in schizophrenia, including mitochondrial hypoplasia, and a dysfunction of the oxidative phosphorylation system, as well as altered mitochondrial-related gene expression. Mitochondrial dysfunction leads to alterations in ATP production and cytoplasmatic calcium concentrations, as well as reactive oxygen species and nitric oxide production. All of the latter processes have been well established as leading to altered synaptic strength or plasticity. Moreover, mitochondria have been shown to play a role in plasticity of neuronal polarity, and studies in the visual cortex show an association between mitochondria and synaptogenesis. Finally, mitochondrial gene upregulation has been observed following synaptic and neuronal activity. This review proposes that mitochondrial dysfunction in schizophrenia could cause, or arise from, anomalies in processes of plasticity in this disorder.

  1. Stem cell mitochondria during aging.

    Science.gov (United States)

    Min-Wen, Jason Chua; Jun-Hao, Elwin Tan; Shyh-Chang, Ng

    2016-04-01

    Mitochondria are the central hubs of cellular metabolism, equipped with their own mitochondrial DNA (mtDNA) blueprints to direct part of the programming of mitochondrial oxidative metabolism and thus reactive oxygen species (ROS) levels. In stem cells, many stem cell factors governing the intricate balance between self-renewal and differentiation have been found to directly regulate mitochondrial processes to control stem cell behaviors during tissue regeneration and aging. Moreover, numerous nutrient-sensitive signaling pathways controlling organismal longevity in an evolutionarily conserved fashion also influence stem cell-mediated tissue homeostasis during aging via regulation of stem cell mitochondria. At the genomic level, it has been demonstrated that heritable mtDNA mutations and variants affect mammalian stem cell homeostasis and influence the risk for human degenerative diseases during aging. Because such a multitude of stem cell factors and signaling pathways ultimately converge on the mitochondria as the primary mechanism to modulate cellular and organismal longevity, it would be most efficacious to develop technologies to therapeutically target and direct mitochondrial repair in stem cells, as a unified strategy to combat aging-related degenerative diseases in the future.

  2. Plant-Derived Anti-Inflammatory Compounds: Hopes and Disappointments regarding the Translation of Preclinical Knowledge into Clinical Progress

    Directory of Open Access Journals (Sweden)

    Robert Fürst

    2014-01-01

    Full Text Available Many diseases have been described to be associated with inflammatory processes. The currently available anti-inflammatory drug therapy is often not successful or causes intolerable side effects. Thus, new anti-inflammatory substances are still urgently needed. Plants were the first source of remedies in the history of mankind. Since their chemical characterization in the 19th century, herbal bioactive compounds have fueled drug development. Also, nowadays, new plant-derived agents continuously enrich our drug arsenal (e.g., vincristine, galantamine, and artemisinin. The number of new, pharmacologically active herbal ingredients, in particular that of anti-inflammatory compounds, rises continuously. The major obstacle in this field is the translation of preclinical knowledge into evidence-based clinical progress. Human trials of good quality are often missing or, when available, are frequently not suitable to really prove a therapeutical value. This minireview will summarize the current situation of 6 very prominent plant-derived anti-inflammatory compounds: curcumin, colchicine, resveratrol, capsaicin, epigallocatechin-3-gallate (EGCG, and quercetin. We will highlight their clinical potential and/or pinpoint an overestimation. Moreover, we will sum up the planned trials in order to provide insights into the inflammatory disorders that are hypothesized to be beneficially influenced by the compound.

  3. Artificial microRNA mediated gene silencing in plants: progress and perspectives.

    Science.gov (United States)

    Tiwari, Manish; Sharma, Deepika; Trivedi, Prabodh Kumar

    2014-09-01

    Homology based gene silencing has emerged as a convenient approach for repressing expression of genes in order to study their functions. For this purpose, several antisense or small interfering RNA based gene silencing techniques have been frequently employed in plant research. Artificial microRNAs (amiRNAs) mediated gene silencing represents one of such techniques which can utilize as a potential tool in functional genomics. Similar to microRNAs, amiRNAs are single-stranded, approximately 21 nt long, and designed by replacing the mature miRNA sequences of duplex within pre-miRNAs. These amiRNAs are processed via small RNA biogenesis and silencing machinery and deregulate target expression. Holding to various refinements, amiRNA technology offers several advantages over other gene silencing methods. This is a powerful and robust tool, and could be applied to unravel new insight of metabolic pathways and gene functions across the various disciplines as well as in translating observations for improving favourable traits in plants. This review highlights general background of small RNAs, improvements made in RNAi based gene silencing, implications of amiRNA in gene silencing, and describes future themes for improving value of this technology in plant science.

  4. Mitochondria and Energetic Depression in Cell Pathophysiology

    Directory of Open Access Journals (Sweden)

    Stephan Zierz

    2009-05-01

    Full Text Available Mitochondrial dysfunction is a hallmark of almost all diseases. Acquired or inherited mutations of the mitochondrial genome DNA may give rise to mitochondrial diseases. Another class of disorders, in which mitochondrial impairments are initiated by extramitochondrial factors, includes neurodegenerative diseases and syndromes resulting from typical pathological processes, such as hypoxia/ischemia, inflammation, intoxications, and carcinogenesis. Both classes of diseases lead to cellular energetic depression (CED, which is characterized by decreased cytosolic phosphorylation potential that suppresses the cell’s ability to do work and control the intracellular Ca2+ homeostasis and its redox state. If progressing, CED leads to cell death, whose type is linked to the functional status of the mitochondria. In the case of limited deterioration, when some amounts of ATP can still be generated due to oxidative phosphorylation (OXPHOS, mitochondria launch the apoptotic cell death program by release of cytochrome c. Following pronounced CED, cytoplasmic ATP levels fall below the thresholds required for processing the ATP-dependent apoptotic cascade and the cell dies from necrosis. Both types of death can be grouped together as a mitochondrial cell death (MCD. However, there exist multiple adaptive reactions aimed at protecting cells against CED. In this context, a metabolic shift characterized by suppression of OXPHOS combined with activation of aerobic glycolysis as the main pathway for ATP synthesis (Warburg effect is of central importance. Whereas this type of adaptation is sufficiently effective to avoid CED and to control the cellular redox state, thereby ensuring the cell survival, it also favors the avoidance of apoptotic cell death. This scenario may underlie uncontrolled cellular proliferation and growth, eventually resulting in carcinogenesis.

  5. Metabolic Pathways in Anopheles stephensi mitochondria

    Science.gov (United States)

    Giulivi, Cecilia; Ross-Inta, Catherine; Horton, Ashley A.; Luckhart, Shirley

    2017-01-01

    No studies have been performed on mitochondria of malaria vector mosquitoes. This information would be valuable in understanding mosquito aging and detoxification of insecticides, two parameters that significantly impact malaria parasite transmission in endemic regions. Here, we report the analyses of respiration and oxidative phosphorylation in mitochondria of cultured cells (ASE line) from Anopheles stephensi, a major vector of malaria in India, Southeast Asia and parts of the Middle East. ASE cell mitochondria shared many features in common with mammalian muscle mitochondria, despite the fact that these cells have a larval origin. However, two major differences with mammalian mitochondria were apparent. One, the glycerol-phosphate shuttle plays a major role in NADH oxidation in ASE cell mitochondria as it does in insect muscle mitochondria. In contrast, mammalian white muscle mitochondria depend primarily on lactate dehydrogenase, whereas red muscle mitochondria depend on the malate-oxaloacetate shuttle. Two, ASE mitochondria were able to oxidize Pro at a rate comparable with that of α-glycerophosphate. However, the Pro pathway appeared to differ from the currently accepted pathway, in that ketoglutarate could be catabolyzed completely by the Krebs cycle or via transamination depending on the ATP need. PMID:18588503

  6. Metabolic pathways in Anopheles stephensi mitochondria.

    Science.gov (United States)

    Giulivi, Cecilia; Ross-Inta, Catherine; Horton, Ashley A; Luckhart, Shirley

    2008-10-15

    No studies have been performed on the mitochondria of malaria vector mosquitoes. This information would be valuable in understanding mosquito aging and detoxification of insecticides, two parameters that have a significant impact on malaria parasite transmission in endemic regions. In the present study, we report the analyses of respiration and oxidative phosphorylation in mitochondria of cultured cells [ASE (Anopheles stephensi Mos. 43) cell line] from A. stephensi, a major vector of malaria in India, South-East Asia and parts of the Middle East. ASE cell mitochondria share many features in common with mammalian muscle mitochondria, despite the fact that these cells are of larval origin. However, two major differences with mammalian mitochondria were apparent. One, the glycerol-phosphate shuttle plays as major a role in NADH oxidation in ASE cell mitochondria as it does in insect muscle mitochondria. In contrast, mammalian white muscle mitochondria depend primarily on lactate dehydrogenase, whereas red muscle mitochondria depend on the malate-oxaloacetate shuttle. Two, ASE mitochondria were able to oxidize proline at a rate comparable with that of alpha-glycerophosphate. However, the proline pathway appeared to differ from the currently accepted pathway, in that oxoglutarate could be catabolized completely by the tricarboxylic acid cycle or via transamination, depending on the ATP need.

  7. 干旱胁迫对3种不同光合类型荒漠植物叶绿体和线粒体超微结构的影响%Effect of Soil Drought Stress on the Ultramicrostructures of Chloroplasts and Mitochondria in Three Desert Plants with Different Photosynthetic Types

    Institute of Scientific and Technical Information of China (English)

    闻志彬; 莱孜提·库里库; 张明理

    2016-01-01

    clear and the thylakoids expanded,but the differences between these two plants were that mitochondria of S.junatovii firstly appeared degradation,and its inclusions were partly lost.For S.laricifolia,the outer membrane of mitochondria was deformed and the ridges were re-duced.The mitochondria of S.arbuscula remained normal,but the chloroplasts slightly expanded.(4 ) Under the severe drought stress,the chloroplasts of S.junatovii and S.laricifolia were damaged and mi-tochondria were degraded.For S.arbuscula,the chloroplasts expanded,the outer membrane of mitochon-dria was deformed and the ridges were reduced.These results have showed that the damage degree of S. arbuscula in chloroplasts and mitochondria under different degree of drought stress was the lowest;For S. junatovii and S.laricifolia,the damage degree of chloroplasts under drought stress was similar;the mi-tochondria had better tolerance to drought stress than chloroplasts in S.laricifolia and S.arbuscula.

  8. RNA metabolism in the regulation of protein synthesis in plants. Progress report, 1975-1979

    Energy Technology Data Exchange (ETDEWEB)

    Key, J L

    1979-01-01

    The major objectives of the research for the contract period covered by this report were (1) to gain an insight into the sequence organization of the DNA of soybean, emphasizing the arrangement of single copy or unique sequences and repetitive sequences of DNA throughout the genome, (2) to characterize soybean RNAs relative to nucleotide sequence complexity and kinetics of synthesis and turnover of poly A/sup +/ mRNA, and (3) to study ribosomal proteins directed to an analysis of possible changes in proteins which relate to the activation of 80S ribosomes and thus mRNA utilization and protein synthesis in response to environmental stimuli. Even with greatly reduced funding compared to that requested, objectives 1 and 2 were substantially accomplished. Because of reduced funding and the 20-month no cost extension, relatively little progress was made on objective 3. Accordingly objectives 1 and 2 will be summarized in some detail; a brief account of progress is presented on objective 3.

  9. 山梨醇在植物中的研究进展%Research Progresses of Sorbitol in Plants

    Institute of Scientific and Technical Information of China (English)

    冯小磊; 苏旭; 赵治海; 王晓明

    2014-01-01

    Sorbitol is the major photosynthetic products and transport materials in rosaceous plant , a lot of works had done on the metabolism and transportation.Meanwhile, some studies showed that sorbitol-related genes into the non-rosaceae could increase its stress resistance. In recent years, a large number of studies indicated that adding sorbitol into plant tissue culture could widely and significantly improve differentiation regeneration , however, the mechanism of that is not clear.This paper summarized the research progress about sorbitol in plants in recent years , it could provide references for understanding sorbitol metabilism pathway , creating highly efficient techniques of plant tissue culture and study the mechanism of sorbitol in tissue culture.%山梨醇是蔷薇科植物主要的光合产物和转运物质,人们对其代谢转运进行了大量研究。山梨醇相关基因转入非蔷薇科植物中,可以提高其抗逆性;在植物离体培养中添加山梨醇可以广泛地、明显地提高愈伤组织的分化和再生能力,但是,对于其促进分化再生的机理尚不明确。概述了近年来山梨醇在植物研究中取得的进展,以期为认识山梨醇代谢途径、创建高效组培技术以及明确山梨醇在组培中的作用机理提供参考。

  10. The role of uncoupling protein 3 regulating calcium ion uptake into mitochondria during sarcopenia

    Science.gov (United States)

    Nikawa, Takeshi; Choi, Inho; Haruna, Marie; Hirasaka, Katsuya; Maita Ohno, Ayako; Kondo Teshima, Shigetada

    Overloaded mitochondrial calcium concentration contributes to progression of mitochondrial dysfunction in aged muscle, leading to sarcopenia. Uncoupling protein 3 (UCP3) is primarily expressed in the inner membrane of skeletal muscle mitochondria. Recently, it has been reported that UCP3 is associated with calcium uptake into mitochondria. However, the mechanisms by which UCP3 regulates mitochondrial calcium uptake are not well understood. Here we report that UCP3 interacts with HS-1 associated protein X-1 (Hax-1), an anti-apoptotic protein that is localized in mitochondria, which is involved in cellular responses to calcium ion. The hydrophilic sequences within the loop 2, matrix-localized hydrophilic domain of mouse UCP3 are necessary for binding to Hax-1 of the C-terminal domain in adjacent to mitochondrial innermembrane. Interestingly, these proteins interaction occur the calcium-dependent manner. Indeed, overexpression of UCP3 significantly enhanced calcium uptake into mitochondria on Hax-1 endogenously expressing C2C12 myoblasts. In addition, Hax-1 knock-down enhanced calcium uptake into mitochondria on both UCP3 and Hax-1 endogenously expressing C2C12 myotubes, but not myoblasts. Finally, the dissociation of UCP3 and Hax-1 enhances calcium uptake into mitochondria in aged muscle. These studies identify a novel UCP3-Hax-1 complex regulates the influx of calcium ion into mitochondria in muscle. Thus, the efficacy of UCP3-Hax-1 in mitochondrial calcium regulation may provide a novel therapeutic approach against mitochondrial dysfunction-related disease containing sarcopenia.

  11. Potential Therapeutic Benefits of Strategies Directed to Mitochondria

    Science.gov (United States)

    Lesnefsky, Edward J.; Stowe, David F.

    2010-01-01

    Abstract The mitochondrion is the most important organelle in determining continued cell survival and cell death. Mitochondrial dysfunction leads to many human maladies, including cardiovascular diseases, neurodegenerative disease, and cancer. These mitochondria-related pathologies range from early infancy to senescence. The central premise of this review is that if mitochondrial abnormalities contribute to the pathological state, alleviating the mitochondrial dysfunction would contribute to attenuating the severity or progression of the disease. Therefore, this review will examine the role of mitochondria in the etiology and progression of several diseases and explore potential therapeutic benefits of targeting mitochondria in mitigating the disease processes. Indeed, recent advances in mitochondrial biology have led to selective targeting of drugs designed to modulate and manipulate mitochondrial function and genomics for therapeutic benefit. These approaches to treat mitochondrial dysfunction rationally could lead to selective protection of cells in different tissues and various disease states. However, most of these approaches are in their infancy. Antioxid. Redox Signal. 13, 279–347. PMID:20001744

  12. Instrumentation and process control for fossil demonstration plants. Quarterly technical progress report, April--June 1977

    Energy Technology Data Exchange (ETDEWEB)

    LeSage, L.G.

    1977-07-01

    Work has been performed on updating the study of the state-of-the-art of instrumentation for Fossil Demonstration Plants (FDP), development of mass-flow and other on-line instruments for FDP, process control analysis for FDP, and organization of a symposium on instrumentation and control for FDP. A Solids/Gas Flow Test Facility (S/GFTF) under construction for instrument development, testing, evaluation, and calibration is described. The development work for several mass-flow and other on-line instruments is described: acoustic flowmeter, capacitive density flowmeter, neutron activation flowmeter and composition analysis system, gamma ray correlation flowmeter, optical flowmeter, and capacitive liquid interface level meter.

  13. Antioxidative and proteolytic systems protect mitochondria from oxidative damage in S-deficient Arabidopsis thaliana.

    Science.gov (United States)

    Ostaszewska-Bugajska, Monika; Rychter, Anna M; Juszczuk, Izabela M

    2015-08-15

    We examined the functioning of the antioxidative defense system in Arabidopsis thaliana under sulphur (S) deficiency with an emphasis on the role of mitochondria. In tissue extracts and in isolated mitochondria from S-deficient plants, the concentration of non-protein thiols declined but protein thiols did not change. Superoxide anion and hydrogen peroxide were accumulated in leaf blades and the generation of superoxide anion by isolated mitochondria was higher. Lower abundance of reduced (GSH) plus oxidized (GSSG) glutathione in the leaf and root tissues, and leaf mitochondria from S-deficient plants was accompanied by a decrease in the level of GSH and the changes in the GSH/GSSG ratios. In the chloroplasts, the total level of glutathione decreased. Lower levels of reduced (AsA) and oxidized (DHA) ascorbate were reflected in much higher ratios of AsA/DHA. Sulphur deficiency led to an increase in the activity of cytosolic, mitochondrial and chloroplastic antioxidative enzymes, peroxidases, catalases and superoxide dismutases. The protein carbonyl level was higher in the leaves of S-deficient plants and in the chloroplasts, while in the roots, leaf and root mitochondria it remained unchanged. Protease activity in leaf extracts of S-deficient plants was higher, but in root extracts it did not differ. The proteolytic system reflected subcellular specificity. In leaf and root mitochondria the protease activity was higher, whereas in the chloroplasts it did not change. We propose that the preferential incorporation of S to protein thiols and activation of antioxidative and proteolytic systems are likely important for the survival of S-deficient plants and that the mitochondria maintain redox homeostasis. Copyright © 2015 Elsevier GmbH. All rights reserved.

  14. Simulation-based biagnostics and control for nuclar power plants. Progress report, April 15, 1992--April 14, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.C.

    1993-01-01

    Advanced simulation-based diagnostics and control guidance systems for the identification and management of off-normal transient events in nuclear power plants is currently under investigation. To date a great deal of progress has been made in effectively and efficiently combining information obtained through fuzzy pattern recognition and macroscopic mass and energy inventory analysis for use in multiple failure diagnostics. Work has also begun on the unique problem of diagnostics and surveillance methodologies for advanced passively-safe reactors systems utilizing both statistical and fuzzy information. Plans are also being formulated for the development of deterministic optimal control algorithms combined with Monte Carlo incremental learning algorithms to be used for the flexible and efficient control of reactor transients.

  15. Cell-size dependent progression of the cell cycle creates homeostasis and flexibility of plant cell size

    Science.gov (United States)

    R. Jones, Angharad; Forero-Vargas, Manuel; Withers, Simon P.; Smith, Richard S.; Traas, Jan; Dewitte, Walter; Murray, James A. H.

    2017-01-01

    Mean cell size at division is generally constant for specific conditions and cell types, but the mechanisms coupling cell growth and cell cycle control with cell size regulation are poorly understood in intact tissues. Here we show that the continuously dividing fields of cells within the shoot apical meristem of Arabidopsis show dynamic regulation of mean cell size dependent on developmental stage, genotype and environmental signals. We show cell size at division and cell cycle length is effectively predicted using a two-stage cell cycle model linking cell growth and two sequential cyclin dependent kinase (CDK) activities, and experimental results concur in showing that progression through both G1/S and G2/M is size dependent. This work shows that cell-autonomous co-ordination of cell growth and cell division previously observed in unicellular organisms also exists in intact plant tissues, and that cell size may be an emergent rather than directly determined property of cells. PMID:28447614

  16. Transition metal catalysis in the mitochondria of living cells

    Science.gov (United States)

    Tomás-Gamasa, María; Martínez-Calvo, Miguel; Couceiro, José R.; Mascareñas, José L.

    2016-09-01

    The development of transition metal catalysts capable of promoting non-natural transformations within living cells can open significant new avenues in chemical and cell biology. Unfortunately, the complexity of the cell makes it extremely difficult to translate standard organometallic chemistry to living environments. Therefore, progress in this field has been very slow, and many challenges, including the possibility of localizing active metal catalysts into specific subcellular sites or organelles, remain to be addressed. Herein, we report a designed ruthenium complex that accumulates preferentially inside the mitochondria of mammalian cells, while keeping its ability to react with exogenous substrates in a bioorthogonal way. Importantly, we show that the subcellular catalytic activity can be used for the confined release of fluorophores, and even allows selective functional alterations in the mitochondria by the localized transformation of inert precursors into uncouplers of the membrane potential.

  17. Perspectives of drug-based neuroprotection targeting mitochondria.

    Science.gov (United States)

    Procaccio, V; Bris, C; Chao de la Barca, J M; Oca, F; Chevrollier, A; Amati-Bonneau, P; Bonneau, D; Reynier, P

    2014-05-01

    Mitochondrial dysfunction has been reported in most neurodegenerative diseases. These anomalies include bioenergetic defect, respiratory chain-induced oxidative stress, defects of mitochondrial dynamics, increase sensitivity to apoptosis, and accumulation of damaged mitochondria with instable mitochondrial DNA. Significant progress has been made in our understanding of the pathophysiology of inherited mitochondrial disorders but most have no effective therapies. The development of new metabolic treatments will be useful not only for rare mitochondrial disorders but also for the wide spectrum of common age-related neurodegenerative diseases shown to be associated with mitochondrial dysfunction. A better understanding of the mitochondrial regulating pathways raised several promising perspectives of neuroprotection. This review focuses on the pharmacological approaches to modulate mitochondrial biogenesis, the removal of damaged mitochondria through mitophagy, scavenging free radicals and also dietary measures such as ketogenic diet. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  18. Interdisciplinary Research and Training Program in the Plant Sciences. Technical progress report, February 1, 1991--November 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Wolk, C.P.

    1992-07-01

    Research on plants continued. Topics include: Molecular basis of symbiotic plant-microbe interations; enzymatic mechanisms and regulation of plant cell wall biosynthesis; molecular mechanisms that regulate the expression of genes in plants; resistance of plants to environmental stress; studies on hormone biosynthesis and action; plant cell wall proteins; interaction of nuclear and organelle genomes; sensor transduction in plants; molecular mechanisms of trafficking in the plant cell; regulation of lipid metabolism; molecular bases of plant disease resistance mechanisms; biochemical and molecular aspects of plant pathogenesis; developmental biology of nitrogen-fixing cyanobacteria; environmental control of plant development and its relation to plant hormones.

  19. Aging synaptic mitochondria exhibit dynamic proteomic changes while maintaining bioenergetic function.

    Science.gov (United States)

    Stauch, Kelly L; Purnell, Phillip R; Fox, Howard S

    2014-04-01

    Aging correlates with a progressive impairment of mitochondrial homeostasis and is an influential factor for several forms of neurodegeneration. However, the mechanisms underlying age-related alterations in synaptosomal mitochondria, a neuronal mitochondria population highly susceptible to insults and critical for brain function, remain incompletely understood. Therefore this study investigates the synaptic mitochondrial proteomic and bioenergetic alterations that occur with age. The utilization of a state of the art quantitative proteomics approach allowed for the comparison of protein expression levels in synaptic mitochondria isolated from 5 (mature), 12 (old), and 24 (aged) month old mice. During the process of aging we find that dynamic proteomic alterations occur in synaptic mitochondria. Despite direct (mitochondrial DNA deletions) and indirect (increased antioxidant protein levels) signs of mitochondrial damage in the aged mice, there was an overall maintenance of mitochondrial function. Therefore the synaptic mitochondrial proteomic changes that occur with aging correlate with preservation of synaptic mitochondrial function.

  20. Maternal inheritance of plastids and mitochondria in Cycas L. (Cycadaceae).

    Science.gov (United States)

    Zhong, Zhi-Rong; Li, Nan; Qian, Dan; Jin, Jian-Hua; Chen, Tao

    2011-12-01

    Cycas is often considered a living fossil, thereby providing a unique model for revealing the evolution of spermatophytes. To date, the genetic inheritance of these archaic plants is not fully understood. The present study seeks to document the process of organelle inheritance in an interspecific cross of Cycas species. Extranuclear organelle DNA from chloroplasts and mitochondria was analyzed using both polymerase chain reaction-restriction fragment length polymorphism analysis and microscopy. Here, we show that the chloroplasts and mitochondria in the progeny of interspecific crosses between Cycas taitungensis and Cycas ferruginea were exclusively inherited from the female parent. Epifluorescence microscopic analyses of the pollen cells from Cycas elongata indicated that there was a significant degradation of organelle DNA in male reproductive cells following maturation; the DNA fluorescent signals were only seen after pollen mitosis two, but not detectable at mature stage. Lack of organelle DNA fluorescent signal in prothallial cells was confirmed by the absence of plastids and mitochondria in electronic microscopic images. In conclusion, these data suggest that the maternal plastid and mitochondrial inheritance in Cycas, native to the old world, are the same as seen in seed plants.

  1. Progress in accident analysis of the HYLIFE-II inertial fusion energy power plant design

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, S; Latkowski, J F; Gomez del Rio, J; Sanz, J

    2000-10-11

    The present work continues our effort to perform an integrated safety analysis for the HYLIFE-II inertial fusion energy (IFE) power plant design. Recently we developed a base case for a severe accident scenario in order to calculate accident doses for HYLIFE-II. It consisted of a total loss of coolant accident (LOCA) in which all the liquid flibe (Li{sub 2}BeF{sub 4}) was lost at the beginning of the accident. Results showed that the off-site dose was below the limit given by the DOE Fusion Safety Standards for public protection in case of accident, and that his dose was dominated by the tritium released during the accident.

  2. 1997 Gordon Research Conference on Plant Cell Walls. Final progress report

    Energy Technology Data Exchange (ETDEWEB)

    Staehelin, A.

    1999-08-25

    The Gordon Research Conference (GRC) on Plant Cell Walls was held at Tilton School, Tilton, New Hampshire, July 18-22, 1997. The conference was well attended with 106 participants. The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both US and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time for formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. In addition to these formal interactions, free time was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.

  3. Progress in long-lived radioactive waste management and disposal at the waste isolation pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Triay, I.R.; Matthews, M.L. [U.S. Dept. of Energy Carlsbad Field Office, New Mexico (United States); Eriksson, L.G. [GRAM, Inc., Albuquerque, NM (United States)

    2001-07-01

    The Salado Formation is buried more than 350 m beneath the sands and cacti of the Chihuahuan Desert and hosts the Waste Isolation Pilot Plant (WIPP) deep geological repository at a depth of approximately 650 m. Since the WIPP repository is at least 10 years ahead of any other repository development for long-lived radioactive waste, other radioactive waste management organizations and institutions could benefit both scientifically and politically from sharing the lessons learned at WIPP. Benefits would include using existing expertise and facilities to cost-effectively address and solve program-specific issues and to train staff. The characteristics of the WIPP repository and infrastructure are described in this paper. (author)

  4. Mitochondria: a target for bacteria.

    Science.gov (United States)

    Lobet, Elodie; Letesson, Jean-Jacques; Arnould, Thierry

    2015-04-01

    Eukaryotic cells developed strategies to detect and eradicate infections. The innate immune system, which is the first line of defence against invading pathogens, relies on the recognition of molecular patterns conserved among pathogens. Pathogen associated molecular pattern binding to pattern recognition receptor triggers the activation of several signalling pathways leading to the establishment of a pro-inflammatory state required to control the infection. In addition, pathogens evolved to subvert those responses (with passive and active strategies) allowing their entry and persistence in the host cells and tissues. Indeed, several bacteria actively manipulate immune system or interfere with the cell fate for their own benefit. One can imagine that bacterial effectors can potentially manipulate every single organelle in the cell. However, the multiple functions fulfilled by mitochondria especially their involvement in the regulation of innate immune response, make mitochondria a target of choice for bacterial pathogens as they are not only a key component of the central metabolism through ATP production and synthesis of various biomolecules but they also take part to cell signalling through ROS production and control of calcium homeostasis as well as the control of cell survival/programmed cell death. Furthermore, considering that mitochondria derived from an ancestral bacterial endosymbiosis, it is not surprising that a special connection does exist between this organelle and bacteria. In this review, we will discuss different mitochondrial functions that are affected during bacterial infection as well as different strategies developed by bacterial pathogens to subvert functions related to calcium homeostasis, maintenance of redox status and mitochondrial morphology.

  5. Dynamic survey of mitochondria by ubiquitin.

    Science.gov (United States)

    Escobar-Henriques, Mafalda; Langer, Thomas

    2014-03-01

    Ubiquitin is a post-translational modifier with proteolytic and non-proteolytic roles in many biological processes. At mitochondria, it performs regulatory homeostatic functions and contributes to mitochondrial quality control. Ubiquitin is essential for mitochondrial fusion, regulates mitochondria-ER contacts, and participates in maternal mtDNA inheritance. Under stress, mitochondrial dysfunction induces ubiquitin-dependent responses that involve mitochondrial proteome remodeling and culminate in organelle removal by mitophagy. In addition, many ubiquitin-dependent mechanisms have been shown to regulate innate immune responses and xenophagy. Here, we review the emerging roles of ubiquitin at mitochondria.

  6. Mitochondria in biology and medicine

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Rasmussen, Lene Juel

    2012-01-01

    pathologies (Luft, 1994). Since 1959, the understanding of mitochondrial cytopathies has evolved immensely and mitochondrial cytopathies are now known to be the largest group of metabolic diseases and to be resulting in a wide variety of pathologies. "Mitochondria in Biology and Medicine" was the title...... of the first annual conference of Society of Mitochondrial Research and Medicine - India. The conference was organized by A. S. Sreedhar, Keshav Singh and Kumarasamy Thangaraj, and was held at The Centre for Cellular and Molecular Biology (CCMB) Hyderabad, India, during 9-10 December 2011. The conference...

  7. Advanced light water reactor plants System 80+{trademark} design certification program. Annual progress report, October 1, 1994--September 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The purpose of this report is to provide the status of the progress that was made towards Design Certification of System 80+{trademark} during the US government`s 1995 fiscal year. The System 80+ Advanced Light Water Reactor (ALWR) is a 3931 MW (1350 MWe) Pressurized Water Reactor (PWR). The design covers an essentially complete plant. It is based on EPRI ALWR Utility Requirements Document (URD) improvements to the Standardized System 80 Nuclear Steam Supply System (NSSS) in operation at Palo Verde Units 1, 2, and 3. The NSSS is a traditional two-loop arrangement with two steam generators, two hot legs and four cold legs, each with a reactor coolant pump. The System 80+ standard design houses the NSSS in a spherical steel containment vessel which is enclosed in a concrete shield building, thus providing the safety advantages of a dual barrier to radioactivity release. Other major features include an all-digital, human-factors-engineered control room, an alternate electrical AC power source, an In-Containment Refueling Water Storage Tank (IRWST), and plant arrangements providing complete separation of redundant trains in safety systems.

  8. Mitochondria-specific accumulation of amyloid β induces mitochondrial dysfunction leading to apoptotic cell death.

    Science.gov (United States)

    Cha, Moon-Yong; Han, Sun-Ho; Son, Sung Min; Hong, Hyun-Seok; Choi, Young-Ju; Byun, Jayoung; Mook-Jung, Inhee

    2012-01-01

    Mitochondria are best known as the essential intracellular organelles that host the homeostasis required for cellular survival, but they also have relevance in diverse disease-related conditions, including Alzheimer's disease (AD). Amyloid β (Aβ) peptide is the key molecule in AD pathogenesis, and has been highlighted in the implication of mitochondrial abnormality during the disease progress. Neuronal exposure to Aβ impairs mitochondrial dynamics and function. Furthermore, mitochondrial Aβ accumulation has been detected in the AD brain. However, the underlying mechanism of how Aβ affects mitochondrial function remains uncertain, and it is questionable whether mitochondrial Aβ accumulation followed by mitochondrial dysfunction leads directly to neuronal toxicity. This study demonstrated that an exogenous Aβ(1-42) treatment, when applied to the hippocampal cell line of mice (specifically HT22 cells), caused a deleterious alteration in mitochondria in both morphology and function. A clathrin-mediated endocytosis blocker rescued the exogenous Aβ(1-42)-mediated mitochondrial dysfunction. Furthermore, the mitochondria-targeted accumulation of Aβ(1-42) in HT22 cells using Aβ(1-42) with a mitochondria-targeting sequence induced the identical morphological alteration of mitochondria as that observed in the APP/PS AD mouse model and exogenous Aβ(1-42)-treated HT22 cells. In addition, subsequent mitochondrial dysfunctions were demonstrated in the mitochondria-specific Aβ(1-42) accumulation model, which proved indistinguishable from the mitochondrial impairment induced by exogenous Aβ(1-42)-treated HT22 cells. Finally, cellular toxicity was directly induced by mitochondria-targeted Aβ(1-42) accumulation, which mimics the apoptosis process in exogenous Aβ(1-42)-treated HT22 cells. Taken together, these results indicate that mitochondria-targeted Aβ(1-42) accumulation is the necessary and sufficient condition for Aβ-mediated mitochondria impairments, and leads

  9. Some progress on the chemistry of natural bioactive terpenoids form Chinese medicinal plants

    Directory of Open Access Journals (Sweden)

    Bing-Nan Zhou

    1991-01-01

    Full Text Available (1 Pseudolaric acids - Novel diterpenes, Pseudolaric acid A, B, C and D were isolated from Pseudolarix kaempferi Gorden (pinaceae. Their structures were assigned by spectroscopic data and chemical correlations. In the contineous studies, the absolute configurations, the conformations in the solutions, the framentation mechanisms of MS and assigments of all NMR spectral signals were also reported. They showed the antifungal and cytotoxic activities. (2 Daphnane diterpenes - In the further studies on the plants of Thymelaeaceae, besides 10 known diterpenes, 16 new daphnane diterpenes were isolated from Daphne genkwa, D. tangutica, D. giraldii, Wikstroemie chamaedaphne. They showed the antifertilities activities. (3 Tripterygium diterpenes 14 new diterpenes were isolated from Triperygium wilfordii, T. regeli and T. hypoglaucum. Some of them showed the antitumor activities. The CD spectra showed that A/B ring of all compoundshave trans configuration as same as tripdiolide and triptolide determined by X-ray diffraction (4 Pregnane glycosides from Marsdenia koi - Two new pregnane glycosides marsdenikoiside A and marsdenikoiside B which can terminate the early pregnancy were isolated from Marsdeia koi. Their structures were elucidated by hydrolysis and spectroscopic methods.

  10. A review on progress of heavy metal removal using adsorbents of microbial and plant origin.

    Science.gov (United States)

    Srivastava, Shalini; Agrawal, S B; Mondal, M K

    2015-10-01

    Heavy metals released into the water bodies and on land surfaces by industries are highly toxic and carcinogenic in nature. These heavy metals create serious threats to all the flora and fauna due to their bioaccumulatory and biomagnifying nature at various levels of food chain. Existing conventional technologies for heavy metal removal are witnessing a downfall due to high operational cost and generation of huge quantity of chemical sludge. Adsorption by various adsorbents appears to be a potential alternative of conventional technologies. Its low cost, high efficiency, and possibility of adsorbent regeneration for reuse and recovery of metal ions for various purposes have allured the scientists to work on this technique. The present review compiles the exhaustive information available on the utilization of bacteria, algae, fungi, endophytes, aquatic plants, and agrowastes as source of adsorbent in adsorption process for removal of heavy metals from aquatic medium. During the last few years, a lot of work has been conducted on development of adsorbents after modification with various chemical and physical techniques. Adsorption of heavy metal ions is a complex process affected by operating conditions. As evident from the literature, Langmuir and Freundlich are the most widely used isotherm models, while pseudo first and second order are popularly studied kinetic models. Further, more researches are required in continuous column system and its practical application in wastewater treatment.

  11. Phylogenetic relationships in Epidendroideae (Orchidaceae), one of the great flowering plant radiations: progressive specialization and diversification.

    Science.gov (United States)

    Freudenstein, John V; Chase, Mark W

    2015-03-01

    The largest subfamily of orchids, Epidendroideae, represents one of the most significant diversifications among flowering plants in terms of pollination strategy, vegetative adaptation and number of species. Although many groups in the subfamily have been resolved, significant relationships in the tree remain unclear, limiting conclusions about diversification and creating uncertainty in the classification. This study brings together DNA sequences from nuclear, plastid and mitochrondrial genomes in order to clarify relationships, to test associations of key characters with diversification and to improve the classification. Sequences from seven loci were concatenated in a supermatrix analysis for 312 genera representing most of epidendroid diversity. Maximum-likelihood and parsimony analyses were performed on this matrix and on subsets of the data to generate trees and to investigate the effect of missing values. Statistical character-associated diversification analyses were performed. Likelihood and parsimony analyses yielded highly resolved trees that are in strong agreement and show significant support for many key clades. Many previously proposed relationships among tribes and subtribes are supported, and some new relationships are revealed. Analyses of subsets of the data suggest that the relatively high number of missing data for the full analysis is not problematic. Diversification analyses show that epiphytism is most strongly associated with diversification among epidendroids, followed by expansion into the New World and anther characters that are involved with pollinator specificity, namely early anther inflexion, cellular pollinium stalks and the superposed pollinium arrangement. All tested characters show significant association with speciation in Epidendroideae, suggesting that no single character accounts for the success of this group. Rather, it appears that a succession of key features appeared that have contributed to diversification, sometimes in

  12. Instrumentation and process control for fossil demonstration plants. Quarterly technical progress report, October--December 1976

    Energy Technology Data Exchange (ETDEWEB)

    LeSage, L. G.; O' Fallon, N. M; Bump, T. R.; Cohn, C. E.; Doering, R. W.; Duffey, D.; Kirsch,; Lipinski, W. C.; Managan, W. W.; Porges, K. G.; Raptis, A. C.

    1977-01-01

    The final report of the state-of-the-art study of instrumentation for process control and safety in large-scale coal conversion and fluidized-bed combustion systems was distributed in November. A conceptual design for the Solids/Gas Flow Test Facility has been initiated, the major components identified, and vendors located. Work on acoustic flow measurement has included theoretical feasibility studies of acoustic/ultrasonic techniques for mass-flow measurements of slurries and solid/gas media. Initial planning was conducted to establish a laboratory facility necessary to verify theoretical findings. A survey of the literature relating to capacitive measurements was begun to provide a basis for conceptual designs and preliminary bench tests of the feasibility of these designs. Conceptual design of a capacitive on-line solids density measuring device and calculations to select the type of system for initial feasibility tests were carried out. Preliminary tests of neutron capture gamma analysis for on-line elemental composition of liquid and solid streams in coal plants indicate that most coal elements can be detected quantitatively through the pipe walls. A computer program for peak-fitting in the gamma spectrum was modified for requirements of this work. A literature search was started to determine the state-of-the-art in dynamic process modeling of fossil energy system components, physical property models, and process control models. A partial review of abstracts from a computerized literature search has identified over 50 references having possible application to process analysis activities in this program.

  13. Development and function of membrane systems in plant tissue. Annual technical progress report, 15 September 1981-15 August 1982

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, J B

    1982-01-01

    Over the past 11 months we have continued investigation of ion transport mechanisms in corn roots and mitochondria. In mitochondria we find that only citrate and isocitrate are transported by the H/sup +//citrate symporter. However, the in vivo function of this carrier remains in doubt because citrate does not appear to be an effective substrate for corn mitochondria. Studies with roots have been directed to why various types of injury or shock all result in temporary blockage of the H/sup +/-efflux pump in the plasmamembrane. It appears this may be due to an injury-mediated Ca/sup 2 +/ influx into the tissue, which by raising free Ca/sup 2 +/ in the cytosal activates calmodulin (CaM). In turn, the Ca.CaM complex appears to activate protein kinase, phosphorylating membrane proteins. It is possible that one of these phosphorylated proteins is responsible for inactivation of the H/sup +/-ATPase. Future work is planned around the consequences of Ca/sup 2 +/ influx into the root cell subsequent to injury, investigating the recovery of the H/sup +/-ATPase and the initiation of the biosyntheses which lead to augmented ion transport.

  14. How to split up: lessons from mitochondria

    OpenAIRE

    Dikov, Daniel; Reichert, Andreas S.

    2011-01-01

    Mitochondria underlie a continuous cycle of fission and fusion. Recent studies published in The EMBO Journal, EMBO Reports and The Journal of Cell Biology identified factors that recruit the fission factor Drp1 to mitochondria and inhibit or activate Drp1 activity.

  15. Mitochondria during androgenesis in Hordeum vulgare

    Directory of Open Access Journals (Sweden)

    Krystyna Idzikowska

    2014-01-01

    Full Text Available Different number of mitochondria of varying structure was observed in particular stages of the development of barley (Hordeum vulgare microspores, stimulated by the in vitro culture to form embryoids. This variability was reflected in different shape of sections, different ratio between total area of mitochondria profiles and area of cytoplasm sections, varying number of cristae, and different density of the matrix. Within the cristae of some mitochondria crystalline inclusions were observed. Mitochondria divided by a contraction. In the matrix of some mitochondria spheric bodies were formed. They were surrounded by one or two membranes. It is suggested that the bi-membrane forms constituted promitochandria, whereas unimembrane forms could constitute promicrobodies.

  16. Assembly of outer-membrane proteins in bacteria and mitochondria.

    Science.gov (United States)

    Tommassen, Jan

    2010-09-01

    The cell envelope of Gram-negative bacteria consists of two membranes separated by the periplasm. In contrast with most integral membrane proteins, which span the membrane in the form of hydrophobic alpha-helices, integral outer-membrane proteins (OMPs) form beta-barrels. Similar beta-barrel proteins are found in the outer membranes of mitochondria and chloroplasts, probably reflecting the endosymbiont origin of these eukaryotic cell organelles. How these beta-barrel proteins are assembled into the outer membrane has remained enigmatic for a long time. In recent years, much progress has been reached in this field by the identification of the components of the OMP assembly machinery. The central component of this machinery, called Omp85 or BamA, is an essential and highly conserved bacterial protein that recognizes a signature sequence at the C terminus of its substrate OMPs. A homologue of this protein is also found in mitochondria, where it is required for the assembly of beta-barrel proteins into the outer membrane as well. Although accessory components of the machineries are different between bacteria and mitochondria, a mitochondrial beta-barrel OMP can be assembled into the bacterial outer membrane and, vice versa, bacterial OMPs expressed in yeast are assembled into the mitochondrial outer membrane. These observations indicate that the basic mechanism of OMP assembly is evolutionarily highly conserved.

  17. Postmortem studies on mitochondria in schizophrenia.

    Science.gov (United States)

    Roberts, Rosalinda C

    2017-09-01

    The aim of this paper is to provide a brief review of mitochondrial structure as it relates to function and then present abnormalities in mitochondria in postmortem schizophrenia with a focus on ultrastructure. Function, morphology, fusion, fission, motility, ΔΨmem, ATP production, mitochondrial derived vesicles, and mitochondria-associated ER membranes will be briefly covered. Pathology in mitochondria has long been implicated in schizophrenia, as shown by genetic, proteomic, enzymatic and anatomical abnormalities. The cortex and basal ganglia will be reviewed. In the anterior cingulate cortex, the number of mitochondria per neuronal somata in layers 5/6 in schizophrenia is decreased by 43%. There are also fewer mitochondria in terminals forming axospinous synapses. In the caudate and putamen the number of mitochondria is abnormal in both glial cells and neurons in schizophrenia subjects, the extent of which depends on treatment, response and predominant lifetime symptoms. Treatment-responsive schizophrenia subjects had about a 40% decrease in the number of mitochondria per synapse in the caudate nucleus and putamen, while treatment resistant cases had normal values. A decrease in mitochondrial density in the neuropil distinguishes paranoid from undifferentiated schizophrenia. The appearance, size and density of mitochondria were normal in the nucleus accumbens. In the substantia nigra, COX subunits were affected in rostral regions. Mitochondrial hyperplasia occurs within axon terminals that synapse onto dopamine neurons, but mitochondria in dopamine neuronal somata are similar in size and number. In schizophrenia, mitochondria are differentially affected depending on the brain region, cell type, subcellular location, treatment status, treatment response and symptoms. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Caspase-6 Induces 7A6 Antigen Localization to Mitochondria During FAS-induced Apoptosis of Jurkat Cells.

    Science.gov (United States)

    Suita, Hiroaki; Shinomiya, Takahisa; Nagahara, Yukitoshi

    2017-04-01

    Mitochondria are central to apoptosis. However, apoptosis progression involving mitochondria is not fully understood. A factor involved in mitochondria-mediated apoptosis is 7A6 antigen. 7A6 localizes to mitochondria from the cytosol during apoptosis, which seems to involve 'effector' caspases. In this study, we investigated the precise role of effector caspases in 7A6 localization to mitochondria during apoptosis. Human T-cell lymphoma Jurkat cells were treated with an antibody against FAS. 7A6 localization was analyzed by confocal laser scanning microscopy and flow cytometry. Caspases activation was determined by western blot analysis. 7A6 localization to mitochondria during anti-FAS-induced apoptosis was significantly reduced by the caspase-6 inhibitor, N-acetyl-Val-Glu-Ile-Asp-aldehyde, but not by the caspase-3 inhibitor, N-acetyl-Asp-Asn-Leu-Asp-aldehyde, nor caspase-7/3 inhibitor, N-acetyl-Asp-Gln-Thr-Asp-aldehyde. Moreover, caspase-6 down-regulation suppressed 7A6 localization to mitochondria. Caspase-6 regulates 7A6 localization to mitochondria during anti-FAS-induced apoptosis of Jurkat cells. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  19. tRNA Biology in Mitochondria

    Directory of Open Access Journals (Sweden)

    Thalia Salinas-Giegé

    2015-02-01

    Full Text Available Mitochondria are the powerhouses of eukaryotic cells. They are considered as semi-autonomous because they have retained genomes inherited from their prokaryotic ancestor and host fully functional gene expression machineries. These organelles have attracted considerable attention because they combine bacterial-like traits with novel features that evolved in the host cell. Among them, mitochondria use many specific pathways to obtain complete and functional sets of tRNAs as required for translation. In some instances, tRNA genes have been partially or entirely transferred to the nucleus and mitochondria require precise import systems to attain their pool of tRNAs. Still, tRNA genes have also often been maintained in mitochondria. Their genetic arrangement is more diverse than previously envisaged. The expression and maturation of mitochondrial tRNAs often use specific enzymes that evolved during eukaryote history. For instance many mitochondria use a eukaryote-specific RNase P enzyme devoid of RNA. The structure itself of mitochondrial encoded tRNAs is also very diverse, as e.g., in Metazoan, where tRNAs often show non canonical or truncated structures. As a result, the translational machinery in mitochondria evolved adapted strategies to accommodate the peculiarities of these tRNAs, in particular simplified identity rules for their aminoacylation. Here, we review the specific features of tRNA biology in mitochondria from model species representing the major eukaryotic groups, with an emphasis on recent research on tRNA import, maturation and aminoacylation.

  20. tRNA Biology in Mitochondria

    Science.gov (United States)

    Salinas-Giegé, Thalia; Giegé, Richard; Giegé, Philippe

    2015-01-01

    Mitochondria are the powerhouses of eukaryotic cells. They are considered as semi-autonomous because they have retained genomes inherited from their prokaryotic ancestor and host fully functional gene expression machineries. These organelles have attracted considerable attention because they combine bacterial-like traits with novel features that evolved in the host cell. Among them, mitochondria use many specific pathways to obtain complete and functional sets of tRNAs as required for translation. In some instances, tRNA genes have been partially or entirely transferred to the nucleus and mitochondria require precise import systems to attain their pool of tRNAs. Still, tRNA genes have also often been maintained in mitochondria. Their genetic arrangement is more diverse than previously envisaged. The expression and maturation of mitochondrial tRNAs often use specific enzymes that evolved during eukaryote history. For instance many mitochondria use a eukaryote-specific RNase P enzyme devoid of RNA. The structure itself of mitochondrial encoded tRNAs is also very diverse, as e.g., in Metazoan, where tRNAs often show non canonical or truncated structures. As a result, the translational machinery in mitochondria evolved adapted strategies to accommodate the peculiarities of these tRNAs, in particular simplified identity rules for their aminoacylation. Here, we review the specific features of tRNA biology in mitochondria from model species representing the major eukaryotic groups, with an emphasis on recent research on tRNA import, maturation and aminoacylation. PMID:25734984

  1. Transient Influx of Nickel in Root Mitochondria Modulates Organic Acid and Reactive Oxygen Species Production in Nickel Hyperaccumulator Alyssum murale*

    Science.gov (United States)

    Agrawal, Bhavana; Czymmek, Kirk J.; Sparks, Donald L.; Bais, Harsh P.

    2013-01-01

    Mitochondria are important targets of metal toxicity and are also vital for maintaining metal homeostasis. Here, we examined the potential role of mitochondria in homeostasis of nickel in the roots of nickel hyperaccumulator plant Alyssum murale. We evaluated the biochemical basis of nickel tolerance by comparing the role of mitochondria in closely related nickel hyperaccumulator A. murale and non-accumulator Alyssum montanum. Evidence is presented for the rapid and transient influx of nickel in root mitochondria of nickel hyperaccumulator A. murale. In an early response to nickel treatment, substantial nickel influx was observed in mitochondria prior to sequestration in vacuoles in the roots of hyperaccumulator A. murale compared with non-accumulator A. montanum. In addition, the mitochondrial Krebs cycle was modulated to increase synthesis of malic acid and citric acid involvement in nickel hyperaccumulation. Furthermore, malic acid, which is reported to form a complex with nickel in hyperaccumulators, was also found to reduce the reactive oxygen species generation induced by nickel. We propose that the interaction of nickel with mitochondria is imperative in the early steps of nickel uptake in nickel hyperaccumulator plants. Initial uptake of nickel in roots results in biochemical responses in the root mitochondria indicating its vital role in homeostasis of nickel ions in hyperaccumulation. PMID:23322782

  2. Transient Influx of nickel in root mitochondria modulates organic acid and reactive oxygen species production in nickel hyperaccumulator Alyssum murale.

    Science.gov (United States)

    Agrawal, Bhavana; Czymmek, Kirk J; Sparks, Donald L; Bais, Harsh P

    2013-03-08

    Mitochondria are important targets of metal toxicity and are also vital for maintaining metal homeostasis. Here, we examined the potential role of mitochondria in homeostasis of nickel in the roots of nickel hyperaccumulator plant Alyssum murale. We evaluated the biochemical basis of nickel tolerance by comparing the role of mitochondria in closely related nickel hyperaccumulator A. murale and non-accumulator Alyssum montanum. Evidence is presented for the rapid and transient influx of nickel in root mitochondria of nickel hyperaccumulator A. murale. In an early response to nickel treatment, substantial nickel influx was observed in mitochondria prior to sequestration in vacuoles in the roots of hyperaccumulator A. murale compared with non-accumulator A. montanum. In addition, the mitochondrial Krebs cycle was modulated to increase synthesis of malic acid and citric acid involvement in nickel hyperaccumulation. Furthermore, malic acid, which is reported to form a complex with nickel in hyperaccumulators, was also found to reduce the reactive oxygen species generation induced by nickel. We propose that the interaction of nickel with mitochondria is imperative in the early steps of nickel uptake in nickel hyperaccumulator plants. Initial uptake of nickel in roots results in biochemical responses in the root mitochondria indicating its vital role in homeostasis of nickel ions in hyperaccumulation.

  3. The mitochondria-plasma membrane contact site.

    Science.gov (United States)

    Westermann, Benedikt

    2015-08-01

    Mitochondria are dynamic organelles that are highly motile and frequently fuse and divide. It has recently become clear that their complex behavior is governed to a large extent by interactions with other cellular structures. This review will focus on a mitochondria-plasma membrane tethering complex that was recently discovered and molecularly analyzed in budding yeast, the Num1/Mdm36 complex. This complex attaches mitochondria to the cell cortex and ensures that a portion of the organelles is retained in mother cells during cell division. At the same time, it supports mitochondrial division and integrates mitochondrial dynamics into cellular architecture. Recent evidence suggests that similar mechanisms might exist also in mammalian cells.

  4. Isolation of mitochondria from tissue culture cells.

    Science.gov (United States)

    Clayton, David A; Shadel, Gerald S

    2014-10-01

    The number of mitochondria per cell varies substantially from cell line to cell line. For example, human HeLa cells contain at least twice as many mitochondria as smaller mouse L cells. This protocol starts with a washed cell pellet of 1-2 mL derived from ∼10⁹ cells grown in culture. The cells are swollen in a hypotonic buffer and ruptured with a Dounce or Potter-Elvehjem homogenizer using a tight-fitting pestle, and mitochondria are isolated by differential centrifugation. © 2014 Cold Spring Harbor Laboratory Press.

  5. Three-dimensional analysis of abnormal ultrastructural alteration in mitochondria of hippocampus of APP/PSEN1 transgenic mouse

    Indian Academy of Sciences (India)

    Ki Ju Choi; Mi Jeong Kim; A Reum Je; Sangmi Jun; Chulhyun Lee; Eunji Lee; Mijung Jo; Yang Hoon Huh; Hee-Seok Kweon

    2014-03-01

    Alzheimer’s disease (AD) is a progressive neurodegenerative disorder. The deterioration of subcellular organelles, including the mitochondria, is another major ultrastructural characteristic of AD pathogenesis, in addition to amyloid plaque deposition. However, the three-dimensional (3-D) study of mitochondrial structural alteration in AD remains poorly understood. Therefore, ultrastructural analysis, 3-D electron tomography, and immunogold electron microscopy were performed in the present study to clarify the abnormal structural alterations in mitochondria caused by the progression of AD in APP/PSEN1 transgenic mice, expressing human amyloid precursor protein, as a model for AD. Amyloid (A) plaques accumulated and dystrophic neurites (DN) developed in the hippocampus of transgenic AD mouse brains. We also identified the loss of peroxiredoxin 3, an endogenous cytoprotective antioxidant enzyme and the accumulation of A in the hippocampal mitochondria of transgenic mice, which differs from those in age-matched wild-type mice. The mitochondria in A plaque-detected regions were severely disrupted, and the patterns of ultrastructural abnormalities were classified into three groups: disappearance of cristae, swelling of cristae, and bulging of the outer membrane. These results demonstrated that morpho-functional alterations of mitochondria and AD progression are closely associated and may be beneficial in investigating the function of mitochondria in AD pathogenesis.

  6. Cyclosporin and mitochondria: a neuroprotective approach

    Directory of Open Access Journals (Sweden)

    Alok Singh

    2013-06-01

    Full Text Available Cyclosporin A (CsA an immunophilin, discovered in 1969 and approved in 1983 to be used as immunosuppressant agent and is widely used in organ transplantation and auto-immune disorders. Its ability to alter mitochondria and apoptotic pathways makes it attractive agent to be employed in variety of diseases including age related neurodegenerative diseases. Mitochondria play pivotal role in cell energetics and reactive oxygen species production and are known to be key regulator of apoptosis hence it is important in a wide range of diseases. The structural and functional properties of mitochondria enable the targeting of drugs supposed to modulate the function of organelle for therapeutic advantage. By targeting mitochondria we can prevent oxidative damage associated with neurodegenerative diseases and ischemia and reperfusion tissue injury. Similarly targeting Bcl-2 can be helpful in cancer by triggering apoptosis. [Int J Basic Clin Pharmacol 2013; 2(3.000: 339-340

  7. Exogenous ether lipids predominantly target mitochondria.

    Directory of Open Access Journals (Sweden)

    Lars Kuerschner

    Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

  8. Mitochondria are not captive bacteria.

    Science.gov (United States)

    Harish, Ajith; Kurland, Charles G

    2017-12-07

    Lynn Sagan's conjecture (1967) that three of the fundamental organelles observed in eukaryote cells, specifically mitochondria, plastids and flagella were once free-living primitive (prokaryotic) cells was accepted after considerable opposition. Even though the idea was swiftly refuted for the specific case of origins of flagella in eukaryotes, the symbiosis model in general was accepted for decades as a realistic hypothesis to describe the endosymbiotic origins of eukaryotes. However, a systematic analysis of the origins of the mitochondrial proteome based on empirical genome evolution models now indicates that 97% of modern mitochondrial protein domains as well their homologues in bacteria and archaea were present in the universal common ancestor (UCA) of the modern tree of life (ToL). These protein domains are universal modular building blocks of modern genes and genomes, each of which is identified by a unique tertiary structure and a specific biochemical function as well as a characteristic sequence profile. Further, phylogeny reconstructed from genome-scale evolution models reveals that Eukaryotes and Akaryotes (archaea and bacteria) descend independently from UCA. That is to say, Eukaryotes and Akaryotes are both primordial lineages that evolved in parallel. Finally, there is no indication of massive inter-lineage exchange of coding sequences during the descent of the two lineages. Accordingly, we suggest that the evolution of the mitochondrial proteome was autogenic (endogenic) and not endosymbiotic (exogenic). Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. The ER mitochondria calcium cycle and ER stress response as therapeutic targets in amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Vedrana eTadic

    2014-05-01

    Full Text Available Amyotrophic lateral sclerosis (ALS is a neurodegenerative disease characterized by progressive loss of upper and lower motor neurons. Although the etiology remains unclear, disturbances in calcium homoeostasis and protein folding are essential features of neurodegeneration in this disorder. Here, we review recent research findings on the interaction between endoplasmic reticulum (ER and mitochondria, and its effect on calcium signaling and oxidative stress. We further provide insights into studies, providing evidence that structures of the ER mitochondria calcium cycle (ERMCC serve as a promising targets for therapeutic approaches for treatment of ALS.

  10. MITOCHONDRIA-TARGETED ANTIOXIDANTS FOR TREATMENT OF PARKINSON’S DISEASE: PRECLINICAL AND CLINICAL OUTCOMES

    Science.gov (United States)

    Jin, Huajun; Kanthasamy, Arthi; Ghosh, Anamitra; Anantharam, Vellareddy; Kalyanaraman, Balaraman; Kanthasamy, Anumantha G.

    2013-01-01

    Parkinson’s disease (PD) is a progressive neurodegenerative disease in the elderly, and no cure or disease-modifying therapies exist. Several lines of evidence suggest that mitochondrial dysfunction and oxidative stress have a central role in the dopaminergic neurodegeneration of PD. In this context, mitochondria-targeted therapies that improve mitochondrial function may have great promise in the prevention and treatment of PD. In this review, we discuss the recent developments in mitochondria-targeted antioxidants and their potential beneficial effects as a therapy for ameliorating mitochondrial dysfunction in PD. PMID:24060637

  11. Strigolactones stimulate arbuscular mycorrhizal fungi by activating mitochondria.

    Directory of Open Access Journals (Sweden)

    Arnaud Besserer

    2006-07-01

    Full Text Available The association of arbuscular mycorrhizal (AM fungi with plant roots is the oldest and ecologically most important symbiotic relationship between higher plants and microorganisms, yet the mechanism by which these fungi detect the presence of a plant host is poorly understood. Previous studies have shown that roots secrete a branching factor (BF that strongly stimulates branching of hyphae during germination of the spores of AM fungi. In the BF of Lotus, a strigolactone was found to be the active molecule. Strigolactones are known as germination stimulants of the parasitic plants Striga and Orobanche. In this paper, we show that the BF of a monocotyledonous plant, Sorghum, also contains a strigolactone. Strigolactones strongly and rapidly stimulated cell proliferation of the AM fungus Gigaspora rosea at concentrations as low as 10(-13 M. This effect was not found with other sesquiterperne lactones known as germination stimulants of parasitic weeds. Within 1 h of treatment, the density of mitochondria in the fungal cells increased, and their shape and movement changed dramatically. Strigolactones stimulated spore germination of two other phylogenetically distant AM fungi, Glomus intraradices and Gl. claroideum. This was also associated with a rapid increase of mitochondrial density and respiration as shown with Gl. intraradices. We conclude that strigolactones are important rhizospheric plant signals involved in stimulating both the pre-symbiotic growth of AM fungi and the germination of parasitic plants.

  12. Role of Mitochondria in Parvovirus Pathology

    OpenAIRE

    Jonna Nykky; Matti Vuento; Leona Gilbert

    2014-01-01

    Proper functioning of the mitochondria is crucial for the survival of the cell. Viruses are able to interfere with mitochondrial functions as they infect the host cell. Parvoviruses are known to induce apoptosis in infected cells, but the role of the mitochondria in parvovirus induced cytopathy is only partially known. Here we demonstrate with confocal and electron microscopy that canine parvovirus (CPV) associated with the mitochondrial outer membrane from the onset of infection. ...

  13. Atypical Cristae Morphology of Human Syncytiotrophoblast Mitochondria

    Science.gov (United States)

    De Los Rios Castillo, Daniela; Zarco-Zavala, Mariel; Olvera-Sanchez, Sofia; Pardo, Juan Pablo; Juarez, Oscar; Martinez, Federico; Mendoza-Hernandez, Guillermo; García-Trejo, José J.; Flores-Herrera, Oscar

    2011-01-01

    Mitochondrial complexes I, III2, and IV from human cytotrophoblast and syncytiotrophoblast associate to form supercomplexes or respirasomes, with the following stoichiometries: I1:(III2)1 and I1:(III2)1–2:IV1–4. The content of respirasomes was similar in both cell types after isolating mitochondria. However, syncytiotrophoblast mitochondria possess low levels of dimeric complex V and do not have orthodox cristae morphology. In contrast, cytotrophoblast mitochondria show normal cristae morphology and a higher content of ATP synthase dimer. Consistent with the dimerizing role of the ATPase inhibitory protein (IF1) (García, J. J., Morales-Ríos, E., Cortés-Hernandez, P., and Rodríguez-Zavala, J. S. (2006) Biochemistry 45, 12695–12703), higher relative amounts of IF1 were observed in cytotrophoblast when compared with syncytiotrophoblast mitochondria. Therefore, there is a correlation between dimerization of complex V, IF1 expression, and the morphology of mitochondrial cristae in human placental mitochondria. The possible relationship between cristae architecture and the physiological function of the syncytiotrophoblast mitochondria is discussed. PMID:21572045

  14. Do we age because we have mitochondria?

    Science.gov (United States)

    Bereiter-Hahn, Jürgen

    2014-01-01

    The process of aging remains a great riddle. Production of reactive oxygen species (ROS) by mitochondria is an inevitable by-product of respiration, which has led to a hypothesis proposing the oxidative impairment of mitochondrial components (e.g., mtDNA, proteins, lipids) that initiates a vicious cycle of dysfunctional respiratory complexes producing more ROS, which again impairs function. This does not exclude other processes acting in parallel or targets for ROS action in other organelles than mitochondria. Given that aging is defined as the process leading to death, the role of mitochondria-based impairments in those organ systems responsible for human death (e.g., the cardiovascular system, cerebral dysfunction, and cancer) is described within the context of "garbage" accumulation and increasing insulin resistance, type 2 diabetes, and glycation of proteins. Mitochondrial mass, fusion, and fission are important factors in coping with impaired function. Both biogenesis of mitochondria and their degradation are important regulatory mechanisms stimulated by physical exercise and contribute to healthy aging. The hypothesis of mitochondria-related aging should be revised to account for the limitations of the degradative capacity of the lysosomal system. The processes involved in mitochondria-based impairments are very similar across a large range of organisms. Therefore, studies on model organisms from yeast, fungi, nematodes, flies to vertebrates, and from cells to organisms also add considerably to the understanding of human aging.

  15. In aging, the vulnerability of rat brain mitochondria is enhanced due to reduced level of 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNP) and subsequently increased permeability transition in brain mitochondria in old animals.

    Science.gov (United States)

    Krestinina, Olga; Azarashvili, Tamara; Baburina, Yulia; Galvita, Anastasia; Grachev, Dmitry; Stricker, Rolf; Reiser, Georg

    2015-01-01

    Aging is accompanied by progressive dysfunction of mitochondria associated with a continuous decrease of their capacity to produce ATP. Mitochondria isolated from brain of aged animals show an increased mitochondrial permeability transition pore (mPTP) opening. We recently detected new regulators of mPTP function in brain mitochondria, the enzyme 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNP) and its substrates 2', 3'-cAMP and 2', 3'-cNADP, and the neuronal protein p42(IP4). Here, we compared parameters of mPTP opening in non-synaptic brain mitochondria isolated from young and old rats. In mitochondria from old rats (>18 months), mPTP opening occurred at a lower threshold of Ca(2+) concentration than in mitochondria from young rats (aging was accompanied by decreased levels of voltage-dependent anion channel (VDAC; by 69%) and of p42(IP4) (by 59%). Thus, reduced levels of CNP in mitochondria could lead to a rise in the concentration of the mPTP promoter 2', 3'-cAMP. The level of CNP and p42(IP4) and, probably VDAC, might be essential for myelination and electrical activity of axons. We propose that in aging the reduction in the level of these proteins leads to mitochondrial dysfunction, in particular, to a decreased threshold Ca(2+) concentration to induce mPTP opening. This might represent initial steps of age-related mitochondrial dysfunction, resulting in myelin and axonal pathology.

  16. Cysteine biosynthesis, in concert with a novel mechanism, contributes to sulfide detoxification in mitochondria of Arabidopsis thaliana

    NARCIS (Netherlands)

    Birke, Hannah; Haas, Florian H.; De Kok, Luit J.; Balk, Janneke; Wirtz, Markus; Hell, Ruediger

    2012-01-01

    In higher plants, biosynthesis of cysteine is catalysed by OAS-TL [O-acetylserine(thiol)lyase], which replaces the activated acetyl group of O-acetylserine with sulfide. The enzyme is present in cytosol, plastids and mitochondria of plant cells. The sole knockout of mitochondrial OAS-TL activity (oa

  17. Cysteine biosynthesis, in concert with a novel mechanism, contributes to sulfide detoxification in mitochondria of Arabidopsis thaliana

    NARCIS (Netherlands)

    Birke, Hannah; Haas, Florian H.; De Kok, Luit J.; Balk, Janneke; Wirtz, Markus; Hell, Ruediger

    2012-01-01

    In higher plants, biosynthesis of cysteine is catalysed by OAS-TL [O-acetylserine(thiol)lyase], which replaces the activated acetyl group of O-acetylserine with sulfide. The enzyme is present in cytosol, plastids and mitochondria of plant cells. The sole knockout of mitochondrial OAS-TL activity

  18. Controlled production of cellulases in plants for biomass conversion. Progress report, June 15, 1996--March 10, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Danna, K.J.

    1997-06-01

    The goal of this project is to facilitate conversion of plant biomass to usable energy by developing transgenic plants that express genes for microbial cellulases, which can be activated after harvest of the plants. In particular, we want to determine the feasibility of targeting an endoglucanase and a cellobiohydrolase to the plant apoplast (cell wall milieu). The apoplast not only contains cellulose, the substrate for the enzymes, but also can tolerate large amounts of foreign protein. To avoid detrimental effects of cellulase expression in plants, we have chosen enzymes with high temperature optima; the genes for these enzymes are from thermophilic organisms that can use cellulose as a sole energy source.

  19. Controlled production of cellulases in plants for biomass conversion. Progress report, June 15, 1996--March 10, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Danna, K.J.

    1997-06-01

    The goal of this project is to facilitate conversion of plant biomass to usable energy by developing transgenic plants that express genes for microbial cellulases, which can be activated after harvest of the plants. In particular, we want to determine the feasibility of targeting an endoglucanase and a cellobiohydrolase to the plant apoplast (cell wall milieu). The apoplast not only contains cellulose, the substrate for the enzymes, but also can tolerate large amounts of foreign protein. To avoid detrimental effects of cellulase expression in plants, we have chosen enzymes with high temperature optima; the genes for these enzymes are from thermophilic organisms that can use cellulose as a sole energy source.

  20. Macroautophagy inhibition maintains fragmented mitochondria to foster T cell receptor-dependent apoptosis.

    Science.gov (United States)

    Corrado, Mauro; Mariotti, Francesca R; Trapani, Laura; Taraborrelli, Lucia; Nazio, Francesca; Cianfanelli, Valentina; Soriano, Maria Eugenia; Schrepfer, Emilie; Cecconi, Francesco; Scorrano, Luca; Campello, Silvia

    2016-08-15

    Mitochondrial dynamics and functionality are linked to the autophagic degradative pathway under several stress conditions. However, the interplay between mitochondria and autophagy upon cell death signalling remains unclear. The T-cell receptor pathway signals the so-called activation-induced cell death (AICD) essential for immune tolerance regulation. Here, we show that this apoptotic pathway requires the inhibition of macroautophagy. Protein kinase-A activation downstream of T-cell receptor signalling inhibits macroautophagy upon AICD induction. This leads to the accumulation of damaged mitochondria, which are fragmented, display remodelled cristae and release cytochrome c, thereby driving apoptosis. Autophagy-forced reactivation that clears the Parkin-decorated mitochondria is as effective in inhibiting apoptosis as genetic interference with cristae remodelling and cytochrome c release. Thus, upon AICD induction regulation of macroautophagy, rather than selective mitophagy, ensures apoptotic progression. © 2016 The Authors.

  1. Research Progress of Rooting on Woody Plant Regeneration Plant%木本植物再生植株生根的研究进展

    Institute of Scientific and Technical Information of China (English)

    王琼; 郭小兵; 郭玉寿

    2014-01-01

    Rooting on the plant regeneration of woody plant was the bottleneck on tissue culture construction system of plant regeneration and rapid propagation technology .Plant growth regulator , endogenous hormon , growth vigor , phenolic com-pound, polyamine, metallic element and gene transformance and so on were discussed comprehensively influence factors of rooting on regeneration plant of woody plant .Through the years of forestry experience , the main influence factors of rooting rate of plant regeneration were analyzed to provide reference for the rapid breeding of native woody plant and factory breeding .%木本植物再生植株生根是组织培养植株再生体系建设和快繁技术的瓶颈。笔者从植物生长调节剂、内源激素、植物生长势、酚类化合物、多胺、金属元素、基因转化及其它因素等8个方面综合论述了木本植物再生植株生根的影响因素,并通过多年的林业经验,总结再生植株生根率提高的主要因素,为实现木本植物再生植株生根的工厂化繁育和乡土树种快速繁育提供借鉴。

  2. The central role of mitochondria in axonal degeneration in multiple sclerosis.

    Science.gov (United States)

    Campbell, Graham R; Worrall, Joseph T; Mahad, Don J

    2014-12-01

    Neurodegeneration in multiple sclerosis (MS) is related to inflammation and demyelination. In acute MS lesions and experimental autoimmune encephalomyelitis focal immune attacks damage axons by injuring axonal mitochondria. In progressive MS, however, axonal damage occurs in chronically demyelinated regions, myelinated regions and also at the active edge of slowly expanding chronic lesions. How axonal energy failure occurs in progressive MS is incompletely understood. Recent studies show that oligodendrocytes supply lactate to myelinated axons as a metabolic substrate for mitochondria to generate ATP, a process which will be altered upon demyelination. In addition, a number of studies have identified mitochondrial abnormalities within neuronal cell bodies in progressive MS, leading to a deficiency of mitochondrial respiratory chain complexes or enzymes. Here, we summarise the mitochondrial abnormalities evident within neurons and discuss how these grey matter mitochondrial abnormalities may increase the vulnerability of axons to degeneration in progressive MS. Although neuronal mitochondrial abnormalities will culminate in axonal degeneration, understanding the different contributions of mitochondria to the degeneration of myelinated and demyelinated axons is an important step towards identifying potential therapeutic targets for progressive MS.

  3. Research Progress on Gnetaceae Plants in the World%买麻藤科植物研究进展

    Institute of Scientific and Technical Information of China (English)

    史胜青; 刘建锋; 江泽平

    2011-01-01

    买麻藤科植物是裸子植物中唯一的藤本植物,具有重要的理论研究和应用开发价值.全世界仅1属约40种,中国发现9种,分布于亚洲、非洲和南美洲的热带和亚热带地区;在理论研究方面,该科系统进化位置特殊,形态结构、化学成分和分子水平上的研究存在很大争议,仍没有解决其在裸子植物与被子植物间所处的进化位置;在应用研究方面,该科既是传统中药又富含芪类、生物碱和黄酮等活性成分,而且果实和叶片可食用;然而,在引种、驯化及培育方面研究薄弱,阻碍了该科资源的开发和利用.本文从资源分布、理论与应用研究以及开发利用等方面综述了买麻藤科植物研究进展,将为今后国内深入开展该科植物的相关研究奠定基础.%Gnetaceae plants, as a sole lianas (rare shrubs or arbors) in gymnosperms, plays an important roles in the studies of theoretics and applications. There is only one genus, and about 40 species in the world and 9 species in China, which distributed in the tropical and subtropical areas of Asia, Africa and South America. On the aspects of theoretical research, it is still disputed for the system evolution between gymnosperms and angiosperms although a large amounts of studies have been carried out on the morphology and anatomy, chemical constituents and molecular biology. On the aspects of applicable research,the constituents of biological activities,stilbene or its derivatives,alkaloid and flavone,etc. ,are greatly abundant in this family. Moreover,some species have been Chinese traditional medicines in history. However,exploiture and utilization have been blocked due to its weakness on the studies of introduction, domestication and cultivation. Consequently, this article reviews that the progress on its distribution of species, the research values of theoretical and applicable research, exploiture and utilization, which will provide an basis for the further

  4. Ethanol induced mitochondria injury and permeability transition pore opening: Role of mitochondria in alcoholic liver disease

    Institute of Scientific and Technical Information of China (English)

    Ming Yan; Ping Zhu; Hui-Min Liu; Hai-Tao Zhang; Li Liu

    2007-01-01

    AIM: To observe changes of mitochondria and investigate the effect of ethanol on mitochondrial permeability transition pore (PTP), mitochondrial membrane potential (MMP, Δψm) and intracellular calcium concentration in hepatocytes by establishing an animal model of alcoholic liver disease (ALD).METHODS: Fourty adult male Wistar rats were randomly divided into two groups, the model group (20) was administered alcohol intragastrically plus an Oliver oil diet to establish an ALD model, and the control group (20) was given an equal amount of normal saline. The ultramicrostructural changes of mitochondria were observed under electron microscopy. Mitochondria of liver was extracted, and patency of PTP, mitochondrial membrane potential (Δψm), mitochondrial mass and intracellular calcium concentration of isolated hepacytes were detected by flow cytometry using rhodamine123 (Rh123), Nonyl-Acridine Orange and calcium fluorescent probe Fluo-3/AM, respectively.RESULTS: Membrane and cristae were broken or disappeared in mitochondria in different shapes under electron microscopy. Some mitochondria showed U shape or megamitochondrion. In the model group, liver mitochondria PTP was broken, and mitochondria swelled, the absorbance at 450 nm, A540 decreased (0.0136 ± 0.0025 vs 0.0321 ± O.0013,model vs control,P<O.01);mitochondria transmembrane potential (239.4638 ± 12.7263 vs 377.5850 ± 16.8119,P<0.01) was lowered;mitochondrial mass (17.4350 ± 1.9880 vs 31.6738 ± 3.4930,P<0.01);and [Ca2+]i was increased in liver cells (7.0020 ± 0.5008 vs 10.2050 ± 0.4701,P<0.01).CONCLUSION:Chronic alcohol intake might lead to broken mitochondria PTP,decreased mitochondria membrane potential and injury,and elevated intracellular Ca2+ production.Ethanol-induced chondriosome injury may be an important mechanism of alcoholic diseases.

  5. Mmb1p binds mitochondria to dynamic microtubules

    Science.gov (United States)

    Fu, Chuanhai; Jain, Deeptee; Costa, Judite; Velve-Casquillas, Guilhem; Tran, Phong T.

    2015-01-01

    Summary Background Mitochondria form a dynamics tubular network within the cell. Proper mitochondria movement and distribution are critical for their localized function in cell metabolism, growth, and survival. In mammalian cells, mechanisms of mitochondria positioning appear dependent on the microtubule cytoskeleton, with kinesin or dynein motors carrying mitochondria as cargos and distributing them throughout the microtubule network. Interestingly, the timescale of microtubule dynamics occurs in seconds, and the timescale of mitochondria distribution occurs in minutes. How does the cell couple these two time constants? Results Fission yeast also relies on microtubules for mitochondria distribution. We report here a new microtubule-dependent but motor-independent mechanism for proper mitochondria positioning in fission yeast. We identify the protein mmb1p, which binds to mitochondria and microtubules. Mmb1p attaches the tubular mitochondria to the microtubule lattice at multiple discrete interaction sites. Mmb1 deletion causes mitochondria to aggregate, with the long-term consequence of defective mitochondria distribution and cell death. Mmb1p decreases microtubule dynamicity. Conclusion Mmb1p is a new microtubule-mitochondria binding protein. We propose that mmb1p act to couple long-term mitochondria distribution to short-term microtubule dynamics by attenuating microtubule dynamics, thus enhancing the mitochondria-microtubule interaction time. PMID:21856157

  6. MIRO1 influences the morphology and intracellular distribution of mitochondria during embryonic cell division in Arabidopsis.

    Science.gov (United States)

    Yamaoka, Shohei; Nakajima, Masaki; Fujimoto, Masaru; Tsutsumi, Nobuhiro

    2011-02-01

    Regulating the morphology and intracellular distribution of mitochondria is essential for embryo development in animals. However, the importance of such regulation is not clearly defined in plants. The evolutionarily conserved Miro proteins are known to be involved in the regulation of mitochondrial morphology and motility. We previously demonstrated that MIRO1, an Arabidopsis thaliana orthologue of the Miro protein, is required for embryogenesis. An insertional mutation in the MIRO1 gene causes arrest of embryonic cell division, leading to abortion of the embryo at an early stage. Here we investigated the role of MIRO1 in the regulation of mitochondrial behaviour in egg cells and early-stage embryos using GFP-labeled mitochondria. Two-photon laser scanning microscopy revealed that, in miro1 mutant egg cells, mitochondria are abnormally enlarged, although egg cell formation is nearly unaffected. After fertilization and subsequent zygotic cell division, the homozygous miro1 mutant two-celled embryo contained a significantly reduced number of mitochondria in its apical cell compared with the wild type, suggesting that the miro1 mutation inhibits proper intracellular distribution of mitochondria, leading to an arrest of embryonic cell division. Our findings suggest that proper mitochondrial morphology and intracellular distribution are maintained by MIRO1 and are vital for embryonic cell division.

  7. Cysteine biosynthesis, in concert with a novel mechanism, contributes to sulfide detoxification in mitochondria of Arabidopsis thaliana.

    Science.gov (United States)

    Birke, Hannah; Haas, Florian H; De Kok, Luit J; Balk, Janneke; Wirtz, Markus; Hell, Rüdiger

    2012-07-15

    In higher plants, biosynthesis of cysteine is catalysed by OAS-TL [O-acetylserine(thiol)lyase], which replaces the activated acetyl group of O-acetylserine with sulfide. The enzyme is present in cytosol, plastids and mitochondria of plant cells. The sole knockout of mitochondrial OAS-TL activity (oastlC) leads to significant reduction of growth in Arabidopsis thaliana. The reason for this phenotype is still enigmatic, since mitochondrial OAS-TL accounts only for approximately 5% of total OAS-TL activity. In the present study we demonstrate that sulfide specifically intoxicates Complex IV activity, but not electron transport through Complexes II and III in isolated mitochondria of oastlC plants. Loss of mitochondrial OAS-TL activity resulted in significant inhibition of dark respiration under certain developmental conditions. The abundance of mitochondrially encoded proteins and Fe-S cluster-containing proteins was not affected in oastlC. Furthermore, oastlC seedlings were insensitive to cyanide, which is detoxified by β-cyano-alanine synthase in mitochondria at the expense of cysteine. These results indicate that in situ biosynthesis of cysteine in mitochondria is not mandatory for translation, Fe-S cluster assembly and cyanide detoxification. Finally, we uncover an OAS-TL-independent detoxification system for sulfide in mitochondria of Arabidopsis that allows oastlC plants to cope with high sulfide levels caused by abiotic stresses.

  8. Progress of nuclear safety for symbiosis and sustainability advanced digital instrumentation, control and information systems for nuclear power plants

    CERN Document Server

    Yoshikawa, Hidekazu

    2014-01-01

    This book introduces advanced methods of computational and information systems allowing readers to better understand the state-of-the-art design and implementation technology needed to maintain and enhance the safe operation of nuclear power plants. The subjects dealt with in the book are (i) Full digital instrumentation and control systems and human?machine interface technologies (ii) Risk? monitoring methods for large and? complex? plants (iii) Condition monitors for plant components (iv) Virtual and augmented reality for nuclear power plants and (v) Software reliability verification and val

  9. Our (Mother's) Mitochondria and Our Mind.

    Science.gov (United States)

    Kramer, Peter; Bressan, Paola

    2017-09-01

    Most of the energy we get to spend is furnished by mitochondria, minuscule living structures sitting inside our cells or dispatched back and forth within them to where they are needed. Mitochondria produce energy by burning down what remains of our meal after we have digested it, but at the cost of constantly corroding themselves and us. Here we review how our mitochondria evolved from invading bacteria and have retained a small amount of independence from us; how we inherit them only from our mother; and how they are heavily implicated in learning, memory, cognition, and virtually every mental or neurological affliction. We discuss why counteracting mitochondrial corrosion with antioxidant supplements is often unwise, and why our mitochondria, and therefore we ourselves, benefit instead from exercise, meditation, sleep, sunshine, and particular eating habits. Finally, we describe how malfunctioning mitochondria force rats to become socially subordinate to others, how such disparity can be evened off by a vitamin, and why these findings are relevant to us.

  10. Melatonin protects lung mitochondria from aging.

    Science.gov (United States)

    Acuña-Castroviejo, Darío; Carretero, Miguel; Doerrier, Carolina; López, Luis C; García-Corzo, Laura; Tresguerres, Jesús A; Escames, Germaine

    2012-06-01

    We assessed whether melatonin administration would prevent the hyperoxidative status that occurs in lung mitochondria with age. Mitochondria from lungs of male and female senescent prone mice at 5 and 10 months of age were studied. Age-dependent mitochondrial oxidative stress was evaluated by measuring the levels of lipid peroxidation and nitrite, glutathione/glutathione disulfide ratio, and glutathione peroxidase and reductase activities. Mitochondrial respiratory chain and oxidative phosphorylation capability were also measured. Age induces a significant oxidative/nitrosative status in lung mitochondria, which exhibited a significantly reduced activity of the respiratory chain and ATP production. These manifestations of age were more pronounced in males than in females. After 9 months of melatonin administration in the drinking water, the hyperoxidative status and functional deficiency of aged lung mitochondria were totally counteracted, and had increased ATP production. The beneficial effects of melatonin were generally similar in both mice genders. Thus, melatonin administration, as a single therapy, maintained fully functioning lung mitochondria during aging, a finding with important consequences in the pathophysiology of lung aging. In view of these data melatonin, the production of which decreases with age, should be considered a preventive therapy against the hyperoxidative status of the aged lungs, and its use may lead to the avoidance of respiratory complications in the elderly.

  11. Mitochondria as target of Quantum dots toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jiahan; Zhang, Yue; Xiao, Qi; Tian, Fangfang; Liu, Xiaorong; Li, Ran; Zhao, Guangyuan; Jiang, Fenglei [State Key Laboratory of Virology and Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Liu, Yi, E-mail: yiliuchem@whu.edu.cn [State Key Laboratory of Virology and Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2011-10-30

    Highlights: {yields} The present work investigated the toxicity of CdTe QDs on the function of mitochondria isolated from rat livers. {yields} These results will help us learn more about QDs toxicity at subcellular (mitochondrial) level. {yields} QDs toxicity on mitochondria indicates that the QDs require to be further improved before they can be safely used in clinic. - Abstract: Quantum dots (QDs) hold great promise in many biological applications, with the persistence of safety concerns about the environment and human health. The present work investigated the potential toxicity of CdTe QDs on the function of mitochondria isolated from rat livers by examining mitochondrial respiration, swelling, and lipid peroxidation. We observed that QDs can significantly affect the mitochondrial membrane properties, bioenergetics and induce mitochondrial permeability transition (MPT). These results will help us learn more about QDs toxicity at subcellular (mitochondrial) level.

  12. Mitochondria in White, Brown, and Beige Adipocytes

    Directory of Open Access Journals (Sweden)

    Miroslava Cedikova

    2016-01-01

    Full Text Available Mitochondria play a key role in energy metabolism in many tissues, including cardiac and skeletal muscle, brain, liver, and adipose tissue. Three types of adipose depots can be identified in mammals, commonly classified according to their colour appearance: the white (WAT, the brown (BAT, and the beige/brite/brown-like (bAT adipose tissues. WAT is mainly involved in the storage and mobilization of energy and BAT is predominantly responsible for nonshivering thermogenesis. Recent data suggest that adipocyte mitochondria might play an important role in the development of obesity through defects in mitochondrial lipogenesis and lipolysis, regulation of adipocyte differentiation, apoptosis, production of oxygen radicals, efficiency of oxidative phosphorylation, and regulation of conversion of white adipocytes into brown-like adipocytes. This review summarizes the main characteristics of each adipose tissue subtype and describes morphological and functional modifications focusing on mitochondria and their activity in healthy and unhealthy adipocytes.

  13. K-Ras and mitochondria: Dangerous liaisons

    Institute of Scientific and Technical Information of China (English)

    Jiri Neuzil; Jakub Rohlena; Lan-Feng Dong

    2012-01-01

    It is well documented that the KRAS oncogene efficiently transforms non-malignant cells,and there is some evidence for the role of mitochondria in this process.Now Peng Huang and colleagues show that K-Ras induction results early on in mitochondria assuming the phenotype consistent with the so-called Warburg effect,i.e.,increased glycolysis and attenuated oxidative phosphorylation.Thus the K-Ras protein capable of swift induction of phenotypic changes typical of cancer cells,yet these changes are reversible,and for cells to irreversibly reach their full malignant potential a much longer K-Ras expression is required,implicating mitochondria in the longer-term effects of the oncogene.

  14. Mitochondria and endocrine function of adipose tissue.

    Science.gov (United States)

    Medina-Gómez, Gema

    2012-12-01

    Excess of adipose tissue is accompanied by an increase in the risk of developing insulin resistance, type 2 diabetes (T2D) and other complications. Nevertheless, total or partial absence of fat or its accumulation in other tissues (lipotoxicity) is also associated to these complications. White adipose tissue (WAT) was traditionally considered a metabolically active storage tissue for lipids while brown adipose tissue (BAT) was considered as a thermogenic adipose tissue with higher oxidative capacity. Nowadays, WAT is also considered an endocrine organ that contributes to energy homeostasis. Experimental evidence tends to link the malfunction of adipose mitochondria with the development of obesity and T2D. This review discusses the importance of mitochondrial function in adipocyte biology and the increased evidences of mitochondria dysfunction in these epidemics. New strategies targeting adipocyte mitochondria from WAT and BAT are also discussed as therapies against obesity and its complications in the near future.

  15. Mitochondria in biology and medicine--2012

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Rasmussen, Lene Juel

    2014-01-01

    As the understanding of mitochondria and their importance for the cell and organism is developing, increasing evidence is demonstrating the organelle to be intricately involved in an extensive range of pathologies. This range of pathologies include general signs of premature aging, neuro-muscular......As the understanding of mitochondria and their importance for the cell and organism is developing, increasing evidence is demonstrating the organelle to be intricately involved in an extensive range of pathologies. This range of pathologies include general signs of premature aging, neuro...... as biomarkers for the diseases and most important, it opens the possibility of a treatment or a cure for a disease. "Mitochondria in Biology and Medicine" was the title of the second annual conference of Society of Mitochondrial Research and Medicine-India. The conference was organized by Rana P. Singh, Keshav...

  16. The Latest Progresses on Plant NAC Transcription Factors Function%植物NAC转录因子功能研究新进展

    Institute of Scientific and Technical Information of China (English)

    陈娜; 蒋晶; 曹必好; 雷建军; 陈长明

    2015-01-01

    NAC (NA M, A TA F1, A TA F2和CUC2)转录因子是植物特有的一类转录因子,在多种陆生植物基因组中已经有超过100个成员被发现和鉴定,是植物基因组中最大的转录因子家族之一。植物NAC转录因子具有多种功能,在植物生长发育、逆境胁迫应答和激素信号转导等过程中具有重要作用。本文就植物NAC转录因子的基本结构特征和生物学功能的研究新进展进行综述。%NAC (NA M, A TA F1, A TA F2 and CUC2) family proteins are the plant-specific transcription factors which are the largest families, and have more than a hundred members in plant. The plant NAC transcription factors have many functions and play important roles in multiple biological processes such as plant development, response to various kinds of stresses, hormonal signal transduction and so on. In here, the progress of the plant NAC transcription factors basic structure and function are reviewed.

  17. 香蕉根际促生菌的研究展望%Progress and Prospect on Plant Growth - promoting Rhizobacteria of Banana Rhizosphere

    Institute of Scientific and Technical Information of China (English)

    李文英; 彭智平; 于俊红; 黄继川; 宋慧敏

    2011-01-01

    植物根际促生菌(plant growth-promoting rhizobacteria,PGPR)是一类具有促进作物生长并增加产量的作用,兼有抑制植物病原菌、根际有害微生物的根际微生物,作为生物肥料和生物农药的重要资源库,PGPR相关研究受到越来越多的重视.着重从PGPR的概念演变、功能机制、研究手段及应用现状等方面进行综述,并在分析香蕉根际促生菌研究现状的基础上,对香蕉PGPR研究的理论意义和现实意义提出讨论与展望.%Plant growth-promoting rhizobacteria (PGPR) are microorganisms colonized in the plant rhizosphere, which can promote the plant growth and yield, and inhibit plant pathogens.As an important resource of biofertilizer and biocontrol agents, PGPR have been paid more and more attention by researchers in the sustainable agriculture.This paper reviewed progresses on the concept development, functioning mechanisms, study techniques and the application of PGPR.In addition, the theoretical and practical significance of banana PG PR were disscused, and some future directions in PGPR study were suggested.

  18. T cells display mitochondria hyperpolarization in human type 1 diabetes.

    Science.gov (United States)

    Chen, Jing; Chernatynskaya, Anna V; Li, Jian-Wei; Kimbrell, Matthew R; Cassidy, Richard J; Perry, Daniel J; Muir, Andrew B; Atkinson, Mark A; Brusko, Todd M; Mathews, Clayton E

    2017-09-07

    T lymphocytes constitute a major effector cell population in autoimmune type 1 diabetes. Despite essential functions of mitochondria in regulating activation, proliferation, and apoptosis of T cells, little is known regarding T cell metabolism in the progression of human type 1 diabetes. In this study, we report, using two independent cohorts, that T cells from patients with type 1 diabetes exhibited mitochondrial inner-membrane hyperpolarization (MHP). Increased MHP was a general phenotype observed in T cell subsets irrespective of prior antigen exposure, and was not correlated with HbA1C levels, subject age, or duration of diabetes. Elevated T cell MHP was not detected in subjects with type 2 diabetes. T cell MHP was associated with increased activation-induced IFNγ production, and activation-induced IFNγ was linked to mitochondria-specific ROS production. T cells from subjects with type 1 diabetes also exhibited lower intracellular ATP levels. In conclusion, intrinsic mitochondrial dysfunction observed in type 1 diabetes alters mitochondrial ATP and IFNγ production; the latter is correlated with ROS generation. These changes impact T cell bioenergetics and function.

  19. Differential production of superoxide by neuronal mitochondria

    Directory of Open Access Journals (Sweden)

    Levin Leonard A

    2008-01-01

    Full Text Available Abstract Background Mitochondrial DNA (mtDNA mutations, which are present in all mitochondria-containing cells, paradoxically cause tissue-specific disease. For example, Leber's hereditary optic neuropathy (LHON results from one of three point mutations mtDNA coding for complex I components, but is only manifested in retinal ganglion cells (RGCs, a central neuron contained within the retina. Given that RGCs use superoxide for intracellular signaling after axotomy, and that LHON mutations increase superoxide levels in non-RGC transmitochondrial cybrids, we hypothesized that RGCs regulate superoxide levels differently than other neuronal cells. To study this, we compared superoxide production and mitochondrial electron transport chain (METC components in isolated RGC mitochondria to mitochondria isolated from cerebral cortex and neuroblastoma SK-N-AS cells. Results In the presence of the complex I substrate glutamate/malate or the complex II substrate succinate, the rate of superoxide production in RGC-5 cells was significantly lower than cerebral or neuroblastoma cells. Cerebral but not RGC-5 or neuroblastoma cells increased superoxide production in response to the complex I inhibitor rotenone, while neuroblastoma but not cerebral or RGC-5 cells dramatically decreased superoxide production in response to the complex III inhibitor antimycin A. Immunoblotting and real-time quantitative PCR of METC components demonstrated different patterns of expression among the three different sources of neuronal mitochondria. Conclusion RGC-5 mitochondria produce superoxide at significantly lower rates than cerebral and neuroblastoma mitochondria, most likely as a result of differential expression of complex I components. Diversity in METC component expression and function could explain tissue specificity in diseases associated with inherited mtDNA abnormalities.

  20. Modulation of Calcium Entry by Mitochondria.

    Science.gov (United States)

    Fonteriz, Rosalba; Matesanz-Isabel, Jessica; Arias-Del-Val, Jessica; Alvarez-Illera, Pilar; Montero, Mayte; Alvarez, Javier

    2016-01-01

    The role of mitochondria in intracellular Ca(2+) signaling relies mainly in its capacity to take up Ca(2+) from the cytosol and thus modulate the cytosolic [Ca(2+)]. Because of the low Ca(2+)-affinity of the mitochondrial Ca(2+)-uptake system, this organelle appears specially adapted to take up Ca(2+) from local high-Ca(2+) microdomains and not from the bulk cytosol. Mitochondria would then act as local Ca(2+) buffers in cellular regions where high-Ca(2+) microdomains form, that is, mainly close to the cytosolic mouth of Ca(2+) channels, both in the plasma membrane and in the endoplasmic reticulum (ER). One of the first targets proposed already in the 1990s to be regulated in this way by mitochondria were the store-operated Ca(2+) channels (SOCE). Mitochondria, by taking up Ca(2+) from the region around the cytosolic mouth of the SOCE channels, would prevent its slow Ca(2+)-dependent inactivation, thus keeping them active for longer. Since then, evidence for this mechanism has accumulated mainly in immunitary cells, where mitochondria actually move towards the immune synapse during T cell activation. However, in many other cell types the available data indicate that the close apposition between plasma and ER membranes occurring during SOCE activation precludes mitochondria from getting close to the Ca(2+)-entry sites. Alternative pathways for mitochondrial modulation of SOCE, both Ca(2+)-dependent and Ca(2+)-independent, have also been proposed, but further work will be required to elucidate the actual mechanisms at work. Hopefully, the recent knowledge of the molecular nature of the mitochondrial Ca(2+) uniporter will allow soon more precise studies on this matter.

  1. Protein trafficking at the crossroads to mitochondria.

    Science.gov (United States)

    Wasilewski, Michal; Chojnacka, Katarzyna; Chacinska, Agnieszka

    2017-01-01

    Mitochondria are central power stations in the cell, which additionally serve as metabolic hubs for a plethora of anabolic and catabolic processes. The sustained function of mitochondria requires the precisely controlled biogenesis and expression coordination of proteins that originate from the nuclear and mitochondrial genomes. Accuracy of targeting, transport and assembly of mitochondrial proteins is also needed to avoid deleterious effects on protein homeostasis in the cell. Checkpoints of mitochondrial protein transport can serve as signals that provide information about the functional status of the organelles. In this review, we summarize recent advances in our understanding of mitochondrial protein transport and discuss examples that involve communication with the nucleus and cytosol.

  2. Industrial Fuel Gas Demonstration Plant Program. Monthly and quarterly progress report, September 1, 1978-September 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-10-01

    Work during the July-September period was concentrated on the preparation of the Task I report. The Commercial Plant estimate was completed and reviewed by MLGW. A MRC review of the estimate was also conducted. A Plant Configuration study was completed and reviewed by MLGW for enclosure in the Demonstration Plant recommendations. The economic analysis was completed. A preliminary draft of the four volumes of the Task I report was provided to all Industrial Team members and MRC for comments, which were received by the week of September 25th.

  3. Subcellular Distribution of NAD+ between Cytosol and Mitochondria Determines the Metabolic Profile of Human Cells.

    Science.gov (United States)

    VanLinden, Magali R; Dölle, Christian; Pettersen, Ina K N; Kulikova, Veronika A; Niere, Marc; Agrimi, Gennaro; Dyrstad, Sissel E; Palmieri, Ferdinando; Nikiforov, Andrey A; Tronstad, Karl Johan; Ziegler, Mathias

    2015-11-13

    The mitochondrial NAD pool is particularly important for the maintenance of vital cellular functions. Although at least in some fungi and plants, mitochondrial NAD is imported from the cytosol by carrier proteins, in mammals, the mechanism of how this organellar pool is generated has remained obscure. A transporter mediating NAD import into mammalian mitochondria has not been identified. In contrast, human recombinant NMNAT3 localizes to the mitochondrial matrix and is able to catalyze NAD(+) biosynthesis in vitro. However, whether the endogenous NMNAT3 protein is functionally effective at generating NAD(+) in mitochondria of intact human cells still remains to be demonstrated. To modulate mitochondrial NAD(+) content, we have expressed plant and yeast mitochondrial NAD(+) carriers in human cells and observed a profound increase in mitochondrial NAD(+). None of the closest human homologs of these carriers had any detectable effect on mitochondrial NAD(+) content. Surprisingly, constitutive redistribution of NAD(+) from the cytosol to the mitochondria by stable expression of the Arabidopsis thaliana mitochondrial NAD(+) transporter NDT2 in HEK293 cells resulted in dramatic growth retardation and a metabolic shift from oxidative phosphorylation to glycolysis, despite the elevated mitochondrial NAD(+) levels. These results suggest that a mitochondrial NAD(+) transporter, similar to the known one from A. thaliana, is likely absent and could even be harmful in human cells. We provide further support for the alternative possibility, namely intramitochondrial NAD(+) synthesis, by demonstrating the presence of endogenous NMNAT3 in the mitochondria of human cells. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Subcellular Distribution of NAD+ between Cytosol and Mitochondria Determines the Metabolic Profile of Human Cells*

    Science.gov (United States)

    VanLinden, Magali R.; Dölle, Christian; Pettersen, Ina K. N.; Kulikova, Veronika A.; Niere, Marc; Agrimi, Gennaro; Dyrstad, Sissel E.; Palmieri, Ferdinando; Nikiforov, Andrey A.; Tronstad, Karl Johan; Ziegler, Mathias

    2015-01-01

    The mitochondrial NAD pool is particularly important for the maintenance of vital cellular functions. Although at least in some fungi and plants, mitochondrial NAD is imported from the cytosol by carrier proteins, in mammals, the mechanism of how this organellar pool is generated has remained obscure. A transporter mediating NAD import into mammalian mitochondria has not been identified. In contrast, human recombinant NMNAT3 localizes to the mitochondrial matrix and is able to catalyze NAD+ biosynthesis in vitro. However, whether the endogenous NMNAT3 protein is functionally effective at generating NAD+ in mitochondria of intact human cells still remains to be demonstrated. To modulate mitochondrial NAD+ content, we have expressed plant and yeast mitochondrial NAD+ carriers in human cells and observed a profound increase in mitochondrial NAD+. None of the closest human homologs of these carriers had any detectable effect on mitochondrial NAD+ content. Surprisingly, constitutive redistribution of NAD+ from the cytosol to the mitochondria by stable expression of the Arabidopsis thaliana mitochondrial NAD+ transporter NDT2 in HEK293 cells resulted in dramatic growth retardation and a metabolic shift from oxidative phosphorylation to glycolysis, despite the elevated mitochondrial NAD+ levels. These results suggest that a mitochondrial NAD+ transporter, similar to the known one from A. thaliana, is likely absent and could even be harmful in human cells. We provide further support for the alternative possibility, namely intramitochondrial NAD+ synthesis, by demonstrating the presence of endogenous NMNAT3 in the mitochondria of human cells. PMID:26432643

  5. 与栽培密度相关的水稻形态基因研究进展%RESEARCH PROGRESS ON PLANT MORPHOLOGICAL GENES RELATED TO PLANTING DENSITY IN RICE(Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    王寅; 徐建伟; 张丹丹; 舒小丽; 吴殿星

    2011-01-01

    The yield of rice is closely related with the density of planting.Compared with traditional hand transplanting,high-density cultivation is more convenient for efficient agricultural production by the novel cultivation methods such as direct seeding,throwing rice seedlings and machine transplanting.In this paper,the relationship of planting density with grain yield was briefly summarized,and the research progress on plant morphological genes related to planting density,i.e.ideal plant architecture,tiller controlling,tiller angle,erected leaves,rolled leaves and narrow leaves were reviewed.%水稻产量与栽培密度密切相关,在直播、抛秧和机插秧等有别于传统手插秧的新型栽培模式下,高密度栽培更加便于农业的高效生产。本文简述了水稻不同栽培密度与产量间的关系,综述了与水稻栽培密度相关的理想株型、分蘖角度控制、分蘖数控制、直立叶、卷叶及窄叶等形态基因的研究及其进展。

  6. Research Progress on the use of Plant Allelopathy in Agriculture and the Physiological and Ecological Mechanisms of Allelopathy

    OpenAIRE

    Fang eCheng; Zhihui eCheng

    2015-01-01

    Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. These biochemicals are known as allelochemicals and have beneficial or detrimental effects on target organisms. Plant allelopathy is one of the modes of interaction between receptor and donor plants and may exert either positive effects (e.g., for agricultural management, such as weed control, crop protection, or crop ...

  7. Ultrastructural changes of mitochondria in human retinoblastoma: correlation with tumor differentiation and invasiveness.

    Science.gov (United States)

    Singh, Lata; Nag, Tapas C; Kashyap, Seema

    2016-05-01

    Retinoblastoma still represents a challenge for pediatric tumors. Mitochondria have been implicated in tumor progression, cell differentiation, and apoptotic pathways. Electron microscopy allows the study of mitochondrial morphology and it is still debated in human retinoblastoma. Demographic, clinical, and histopathological parameters were recorded in 17 enucleated retinoblastoma specimens. Hematoxylin and eosin staining was performed to study tumor characteristics and the extent of invasion in ocular structures. The aim of this study was to describe and analyze the mitochondrial morphology in human retinoblastoma by transmission electron microscopy (TEM). There was a male preponderance in our study. Ages ranged from 2 to 78 months. Histopathological analysis revealed that 15 (88.2 %) tumors were poorly differentiated retinoblastomas. Massive choroidal invasion was the most frequent histopathological high-risk factor among the others. Histopathological high-risk factors were found in 7/17 (41.1 %) cases. Tumor samples of all patients were examined by means of TEM. All cases showed tumor cells with high nucleocytoplasmic ratio. Poorly differentiated retinoblastoma cases showed fewer mitochondria, scant cytoplasm, disorganized organelles (mitochondria), and necrosis, whereas well-differentiated retinoblastomas had larger number of mitochondria and more organized organelles. However, there was no significant difference in mitochondrial changes between invasive and noninvasive tumors. Our study observed that cristolysis and swollen mitochondria were more frequent in retinoblastoma tumors. Understanding the structural and functional characteristics of mitochondria in retinoblastoma might be essential for the design of future therapeutic strategies. The authors have no proprietary or commercial interest in any materials discussed in this article.

  8. Method: automatic segmentation of mitochondria utilizing patch classification, contour pair classification, and automatically seeded level sets.

    Science.gov (United States)

    Giuly, Richard J; Martone, Maryann E; Ellisman, Mark H

    2012-02-09

    While progress has been made to develop automatic segmentation techniques for mitochondria, there remains a need for more accurate and robust techniques to delineate mitochondria in serial blockface scanning electron microscopic data. Previously developed texture based methods are limited for solving this problem because texture alone is often not sufficient to identify mitochondria. This paper presents a new three-step method, the Cytoseg process, for automated segmentation of mitochondria contained in 3D electron microscopic volumes generated through serial block face scanning electron microscopic imaging. The method consists of three steps. The first is a random forest patch classification step operating directly on 2D image patches. The second step consists of contour-pair classification. At the final step, we introduce a method to automatically seed a level set operation with output from previous steps. We report accuracy of the Cytoseg process on three types of tissue and compare it to a previous method based on Radon-Like Features. At step 1, we show that the patch classifier identifies mitochondria texture but creates many false positive pixels. At step 2, our contour processing step produces contours and then filters them with a second classification step, helping to improve overall accuracy. We show that our final level set operation, which is automatically seeded with output from previous steps, helps to smooth the results. Overall, our results show that use of contour pair classification and level set operations improve segmentation accuracy beyond patch classification alone. We show that the Cytoseg process performs well compared to another modern technique based on Radon-Like Features. We demonstrated that texture based methods for mitochondria segmentation can be enhanced with multiple steps that form an image processing pipeline. While we used a random-forest based patch classifier to recognize texture, it would be possible to replace this with

  9. Method: automatic segmentation of mitochondria utilizing patch classification, contour pair classification, and automatically seeded level sets

    Directory of Open Access Journals (Sweden)

    Giuly Richard J

    2012-02-01

    Full Text Available Abstract Background While progress has been made to develop automatic segmentation techniques for mitochondria, there remains a need for more accurate and robust techniques to delineate mitochondria in serial blockface scanning electron microscopic data. Previously developed texture based methods are limited for solving this problem because texture alone is often not sufficient to identify mitochondria. This paper presents a new three-step method, the Cytoseg process, for automated segmentation of mitochondria contained in 3D electron microscopic volumes generated through serial block face scanning electron microscopic imaging. The method consists of three steps. The first is a random forest patch classification step operating directly on 2D image patches. The second step consists of contour-pair classification. At the final step, we introduce a method to automatically seed a level set operation with output from previous steps. Results We report accuracy of the Cytoseg process on three types of tissue and compare it to a previous method based on Radon-Like Features. At step 1, we show that the patch classifier identifies mitochondria texture but creates many false positive pixels. At step 2, our contour processing step produces contours and then filters them with a second classification step, helping to improve overall accuracy. We show that our final level set operation, which is automatically seeded with output from previous steps, helps to smooth the results. Overall, our results show that use of contour pair classification and level set operations improve segmentation accuracy beyond patch classification alone. We show that the Cytoseg process performs well compared to another modern technique based on Radon-Like Features. Conclusions We demonstrated that texture based methods for mitochondria segmentation can be enhanced with multiple steps that form an image processing pipeline. While we used a random-forest based patch classifier to

  10. 薄荷属植物选种育种研究进展%Research progress on seed selection and breeding of Mentha's plants

    Institute of Scientific and Technical Information of China (English)

    周露; 谢文申

    2012-01-01

    综述了薄荷属植物挥发性成分的主要化学类型及近年来国内外薄荷属植物在选种育种方面的研究进展及发展趋势.希望对促进我国现阶段薄荷属植物的选育种工作有所帮助.%In this paper, the main chemical types of the volatility components in Mentha are summarized, and the research progress and developing tendency on seed selection and breeding of the plants are reviewed.

  11. Development of innovative techniques and principles that may be used as models to improve plant performance. Technical progress report, February 1, 1991--January 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, W.W.; Burton, G.W.

    1991-09-01

    Methods and techniques for transferring germplasm from wild to cultivated species are being developed. The transferred germplasm is being shown to be valuable in plant breeding and in cultivar development. Forty cytoplasms from the wild grassy subspecies monodii (primary gene pool) of Pennisetum glaucum are being tested for cytoplasmic effects on morphological characteristics and forage yield. A`-genome chromosomes from P. purpureum (secondary gene pool) have been transferred to cultivated pearl millet. The A`-chromosome derived lines have been developed into excellent male pollinator lines to produce a new high quality, high yielding grain hybrid for the US. Significant progress is being made in transferring the genes controlling apomixis (to produce true-breeding hybrids) from the tertiary gene pool to cultivated pearl millet. Backcross-4 plants are more pearl millet-like and reproduce by apomixis. New genome combinations have been produced in the apomixis genes transfer program which demonstrate the impact of apomixis on speciation and evolution.

  12. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species, Quarterly technical progress report, December 20, 1995--March 20, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Kochian, L.; Brady, D.; Last, M.; Ebbs, S.

    1995-12-01

    Although the period covered by this progress report began on December 20, 1994, which was the date that DOE approved the Interagency Agreement, the agreement was not approved by USDA until January 9, 1995 and the first scientists working on the project were not hired until February 1, 1995. The first goal of the research supported by the Interagency Agreement is to use hydroponic techniques to identify plant species and genotypes with potential for heavy metal hyperaccumulation for planting on a test site at Silverbow Creek and for radionuclide ({sup 90}Sr and {sup 137}Cs) accumulation on a test site at INEL, Idaho, later this year. The second goal of this research is to identify soil amendment procedures that will enhance the bioavailability of heavy metals and radionuclides in the soil without increasing the movement of the contaminants of concern (COC`s) into the groundwater. Our initial research covered in this report focuses on the first goal.

  13. Mitochondria in biology and medicine--2012

    DEFF Research Database (Denmark)

    Madsen, Claus Desler; Rasmussen, Lene Juel

    2014-01-01

    as biomarkers for the diseases and most important, it opens the possibility of a treatment or a cure for a disease. "Mitochondria in Biology and Medicine" was the title of the second annual conference of Society of Mitochondrial Research and Medicine-India. The conference was organized by Rana P. Singh, Keshav...

  14. Toxicity of polyhydroxylated fullerene to mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Li-Yun [State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Gao, Jia-Ling [Department of Chemistry, College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023 (China); Gao, Tian; Dong, Ping; Ma, Long; Jiang, Feng-Lei [State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Liu, Yi, E-mail: yiliuchem@whu.edu.cn [State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2016-01-15

    Highlights: • Fullerenol-induced mitochondrial dysfunction was investigated at mitochondrial level. • Fullerenol disturbed mitochondrial inner membrane in polar protein regions. • Fullerenol affected the inner membrane and respiration chain of mitochondria. - Abstract: Mitochondrial dysfunction is considered as a crucial mechanism of nanomaterial toxicity. Herein, we investigated the effects of polyhydroxylated fullerene (C{sub 60}(OH){sub 44}, fullerenol), a model carbon-based nanomaterial with high water solubility, on isolated mitochondria. Our study demonstrated that fullerenol enhanced the permeabilization of mitochondrial inner membrane to H{sup +} and K{sup +} and induced mitochondrial permeability transition (MPT). The fullerenol-induced swelling was dose-dependent and could be effectively inhibited by MPT inhibitors such as cyclosporin A (CsA), adenosine diphosphate (ADP), ruthenium red (RR) and ethylenediaminetetraacetic acid (EDTA). After treating the mitochondria with fullerenol, the mitochondrial membrane potential (MMP) was found collapsed in a concentration-independent manner. The fluorescence anisotropy of hematoporphyrin (HP) changed significantly with the addition of fullerenol, while that of 1,6-diphenyl-hexatriene (DPH) changed slightly. Moreover, a decrease of respiration state 3 and increase of respiration state 4 were observed when mitochondria were energized with complex II substrate succinate. The results of transmission electron microscopy (TEM) provided direct evidence that fullerenol damaged the mitochondrial ultrastructure. The investigations can provide comprehensive information to elucidate the possible toxic mechanism of fullerenols at subcellular level.

  15. Mitochondria targeting nano agents in cancer therapeutics

    Science.gov (United States)

    Zhang, Xiao-Ying; Zhang, Pei-Ying

    2016-01-01

    Mitochondria have emerged as noteworthy therapeutic targets as their physiological functions are often altered in pathological conditions such as cancer. The electronic databases of MEDLINE, EMBASE and PubMed were searched for recent studies reporting the importance of mitochondria targeting nanoagents in cancer therapeutics. The concluding remarks of the above papers mostly confirmed the growing potential of these novel nanoagents in the area of anticancer research. Furthermore, numerous studies demonstrated the immense potential of nanocarriers in delivering mitochondria-acting compounds to their target site. Among the assemblage of nanomaterials, carbon nanotubes (CNTs) are becoming more prominent for drug delivery due to favorable attributes including their unique shape, which promotes cellular uptake, and large aspect ratio that facilitates conjugation of bioactive molecules on their surface. The present review focused on the current view of variable options available in mitochondria-targeting anticancer therapeutics. It may be concluded that improvements are essential for its establishment as a gold standard therapeutic option especially in the clinical setting. PMID:28105197

  16. Mitochondria in biology and medicine--2012.

    Science.gov (United States)

    Desler, Claus; Rasmussen, Lene Juel

    2014-05-01

    As the understanding of mitochondria and their importance for the cell and organism is developing, increasing evidence is demonstrating the organelle to be intricately involved in an extensive range of pathologies. This range of pathologies include general signs of premature aging, neuro-muscular dysfunctions, cancer, diabetes, various heart diseases, inflammation and other conditions not previously known to be related to mitochondrial function. A better understanding of mitochondria therefore allows a better understanding of related pathologies. It enables the usage of mitochondrial function as biomarkers for the diseases and most important, it opens the possibility of a treatment or a cure for a disease. "Mitochondria in Biology and Medicine" was the title of the second annual conference of Society of Mitochondrial Research and Medicine-India. The conference was organized by Rana P. Singh, Keshav Singh and Kumarasamy Thangaraj, and was held at the newly opened School of Life Sciences, Central University of Gujarat (CUG), Gandhinagar, India, during 2-3 November 2012. The conference featured talks from internationally renowned scientists within the field of mitochondrial research and offered both students and fellow researchers a comprehensive update to the newest research within the field. This paper summarizes key outcomes of the presentations. Copyright © 2013 © Elsevier B.V. and Mitochondria Research Society. Published by Elsevier B.V. All rights reserved.

  17. Mechanisms by Which Different Functional States of Mitochondria Define Yeast Longevity

    Science.gov (United States)

    Beach, Adam; Leonov, Anna; Arlia-Ciommo, Anthony; Svistkova, Veronika; Lutchman, Vicky; Titorenko, Vladimir I.

    2015-01-01

    Mitochondrial functionality is vital to organismal physiology. A body of evidence supports the notion that an age-related progressive decline in mitochondrial function is a hallmark of cellular and organismal aging in evolutionarily distant eukaryotes. Studies of the baker’s yeast Saccharomyces cerevisiae, a unicellular eukaryote, have led to discoveries of genes, signaling pathways and chemical compounds that modulate longevity-defining cellular processes in eukaryotic organisms across phyla. These studies have provided deep insights into mechanistic links that exist between different traits of mitochondrial functionality and cellular aging. The molecular mechanisms underlying the essential role of mitochondria as signaling organelles in yeast aging have begun to emerge. In this review, we discuss recent progress in understanding mechanisms by which different functional states of mitochondria define yeast longevity, outline the most important unanswered questions and suggest directions for future research. PMID:25768339

  18. A rapid and robust assay for detection of S-phase cell cycle progression in plant cells and tissues by using ethynyl deoxyuridine

    Directory of Open Access Journals (Sweden)

    Horváth Gábor V

    2010-01-01

    Full Text Available Abstract Background Progress in plant cell cycle research is highly dependent on reliable methods for detection of cells replicating DNA. Frequency of S-phase cells (cells in DNA synthesis phase is a basic parameter in studies on the control of cell division cycle and the developmental events of plant cells. Here we extend the microscopy and flow cytometry applications of the recently developed EdU (5-ethynyl-2'-deoxyuridine-based S-phase assay to various plant species and tissues. We demonstrate that the presented protocols insure the improved preservation of cell and tissue structure and allow significant reduction in assay duration. In comparison with the frequently used detection of bromodeoxyuridine (BrdU and tritiated-thymidine incorporation, this new methodology offers several advantages as we discuss here. Results Applications of EdU-based S-phase assay in microscopy and flow cytometry are presented by using cultured cells of alfalfa, Arabidopsis, grape, maize, rice and tobacco. We present the advantages of EdU assay as compared to BrdU-based replication assay and demonstrate that EdU assay -which does not require plant cell wall digestion or DNA denaturation steps, offers reduced assay duration and better preservation of cellular, nuclear and chromosomal morphologies. We have also shown that fast and efficient EdU assay can also be an efficient tool for dual parameter flow cytometry analysis and for quantitative assessment of replication in thick root samples of rice. Conclusions In plant cell cycle studies, EdU-based S-phase detection offers a superior alternative to the existing S-phase assays. EdU method is reliable, versatile, fast, simple and non-radioactive and it can be readily applied to many different plant systems.

  19. Jurassic PARK2: You eat your mitochondria, and you are what your mitochondria eat.

    Science.gov (United States)

    Dorn, Gerald W

    2016-01-01

    Park2/Parkin is a central mediator of selective mitochondrial autophagy for mitochondrial quality control. We showed in mouse hearts that PINK1/Mfn2/Park2 mediated generalized mitophagy is essential to the normal perinatal transition from fetal mitochondria that prefer carbohydrates as metabolic substrates to adult fatty-acid metabolizing mitochondria. Our findings demonstrate how functional interactions between mitophagic mitochondrial removal and biogenic mitochondrial replacement facilitate metabolic maturation of the heart.

  20. Intermembrane space proteome of yeast mitochondria.

    Science.gov (United States)

    Vögtle, F-Nora; Burkhart, Julia M; Rao, Sanjana; Gerbeth, Carolin; Hinrichs, Jens; Martinou, Jean-Claude; Chacinska, Agnieszka; Sickmann, Albert; Zahedi, René P; Meisinger, Chris

    2012-12-01

    The intermembrane space (IMS) represents the smallest subcompartment of mitochondria. Nevertheless, it plays important roles in the transport and modification of proteins, lipids, and metal ions and in the regulation and assembly of the respiratory chain complexes. Moreover, it is involved in many redox processes and coordinates key steps in programmed cell death. A comprehensive profiling of IMS proteins has not been performed so far. We have established a method that uses the proapoptotic protein Bax to release IMS proteins from isolated mitochondria, and we profiled the protein composition of this compartment. Using stable isotope-labeled mitochondria from Saccharomyces cerevisiae, we were able to measure specific Bax-dependent protein release and distinguish between quantitatively released IMS proteins and the background efflux of matrix proteins. From the known 31 soluble IMS proteins, 29 proteins were reproducibly identified, corresponding to a coverage of >90%. In addition, we found 20 novel intermembrane space proteins, out of which 10 had not been localized to mitochondria before. Many of these novel IMS proteins have unknown functions or have been reported to play a role in redox regulation. We confirmed IMS localization for 15 proteins using in organello import, protease accessibility upon osmotic swelling, and Bax-release assays. Moreover, we identified two novel mitochondrial proteins, Ymr244c-a (Coa6) and Ybl107c (Mic23), as substrates of the MIA import pathway that have unusual cysteine motifs and found the protein phosphatase Ptc5 to be a novel substrate of the inner membrane protease (IMP). For Coa6 we discovered a role as a novel assembly factor of the cytochrome c oxidase complex. We present here the first and comprehensive proteome of IMS proteins of yeast mitochondria with 51 proteins in total. The IMS proteome will serve as a valuable source for further studies on the role of the IMS in cell life and death.

  1. Research Progress on Waterlogging Resistance of Plants%植物抗涝性研究进展

    Institute of Scientific and Technical Information of China (English)

    王丽; 李瑞莲; 周仲华; 周文新; 孙红梅; 王峰

    2013-01-01

    In this article,effects of waterlogging stress on growth and morphology,and physiology and biochemical changes of plants were summarized,the waterlogging tolerance mechanism of plants was discussed,and the research methods on waterlogging stress were sunnarized.Moreover,the existing problems on waterlogging stress researches of plants were described,and then the effective ways on improving the waterlogging resistance of plants were put forward,such as cloning waterlogging resistance genes by biotechnology,breeding new varieties with waterlogging resistance by transgenic technology and strengthening field management of plants,and so on.%综述了涝渍胁迫对植物的生长形态、生理生化变化等方面的影响,论述了植物抗涝的机制,总结了植物涝渍胁迫研究的方法,阐述了植物涝渍胁迫研究方面存在的问题,提出了利用生物技术克隆耐涝基因,通过转基因技术培育抗涝性植物新品种,同时加强植物的田间管理等提高植物抗涝性的途径.

  2. 植物表皮蜡质及相关基因研究进展%Research progress of plant cuticular wax and related genes

    Institute of Scientific and Technical Information of China (English)

    陈伟; 刘德春; 杨莉; 刘山蓓; 刘勇

    2016-01-01

    植物表皮蜡质是覆盖在所有陆生植物与空气接触部位的一层疏水性的保护屏障,具有调节植物非气孔性失水、抵抗紫外线伤害、维持植物表面的清洁、抵御病虫害侵袭等功能,对植物的生长发育以及适应外界环境起到了非常重要的作用。植物表皮蜡质分为内表皮蜡质和外表皮蜡质,内表皮蜡质一般为无定型状态,外表皮蜡质多自我组装成各种形态的蜡质晶体。植物表皮蜡质成分复杂,一般由脂肪族化合物包括脂肪酸、烷烃、醛、醇、酮、酯以及萜类和一些小分子次级代谢物组成。目前关于植物表皮蜡质合成及运输机理的研究取得了重要的进展。研究者们从植物突变体中鉴定出了大量蜡质合成、运输及调控相关基因,完善了植物蜡质合成调控网络,为后续研究奠定了坚实的基础。本文对近年来植物表皮蜡质的合成与运输途径及其相关基因的研究进行了综述,并对植物蜡质研究的前景进行探讨与展望。%Plant cuticular wax is a hydrophobic barrier that covers the aerial surfaces of all terrestrial plants. It has the function of regulating the plant non-stomatal water loss, protecting against UV damage, maintaining the plant surface clean, resistance to insects and pathogens, and so on. It plays an important role in plant growth and adaptation to environment. Plant cuticular wax is divided into intracuticular wax and epicuticular wax, the intracuticular wax is generally amorphous state, and the epicuticular wax is always self-assembled into various forms of wax crystal. The chemical composition of plant cuticular wax is complex, and it is generally composed of aliphatic compounds including fatty acids, alkanes, aldehydes, alcohols, ketones, esters, terpenes and small molecular secondary metabolites. At present, it has made great progress about plant cuticular wax synthesis and transport mechanism. Researchers

  3. Mitochondria-driven assembly of a cortical anchor for mitochondria and dynein.

    Science.gov (United States)

    Kraft, Lauren M; Lackner, Laura L

    2017-10-02

    Interorganelle contacts facilitate communication between organelles and impact fundamental cellular functions. In this study, we examine the assembly of the MECA (mitochondria-endoplasmic reticulum [ER]-cortex anchor), which tethers mitochondria to the ER and plasma membrane. We find that the assembly of Num1, the core component of MECA, requires mitochondria. Once assembled, Num1 clusters persistently anchor mitochondria to the cell cortex. Num1 clusters also function to anchor dynein to the plasma membrane, where dynein captures and walks along astral microtubules to help orient the mitotic spindle. We find that dynein is anchored by Num1 clusters that have been assembled by mitochondria. When mitochondrial inheritance is inhibited, Num1 clusters are not assembled in the bud, and defects in dynein-mediated spindle positioning are observed. The mitochondria-dependent assembly of a dual-function cortical anchor provides a mechanism to integrate the positioning and inheritance of the two essential organelles and expands the function of organelle contact sites. © 2017 Kraft and Lackner.

  4. [Signal transduction in plant development: Chemical and biochemical approaches to receptor identification]. Progress report, [May 15, 1993--May 14, 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    Progress is reported on studies concerning NAD(P)H-2,6-DMBQ oxidoreductase of Striga asiatica aimed at elucidating basic biochemical parameters of Striga. Reported studies include characterization of the enzyme, development of Striga molecular genetics, and development of a redox model for germination control.

  5. 植物油基塑料的研究进展%Progress on Plant Oil based Plastics

    Institute of Scientific and Technical Information of China (English)

    魏薇; 张星; 王朝; 张立群

    2013-01-01

    利用植物油为原料,通过各种方法制备得到了许多具有应用价值的植物油基塑料,这些植物油基塑料部分可替代石油基塑料,缓解石油危机,符合可持续发展的要求;同时,由于植物油来源广泛,且其产物具有内在的生物可降解性能,在日常生活和医学领域中有着广阔的应用潜力.通过对不同合成方法制备植物油基塑料的工作进行综述,并对部分材料的适用范围、局限以及可行性进行简单的分析,对今后在植物油基塑料上的研究具有一定的意义.%Plant oil has become to be one of the most important bio-feedstock,and many plant-oil-based plastics with wide applications are synthesized via various methods.These plant-oil-based plastics can partly replace petroleum-based plastics,ease the oil crisis,and meet the demand for sustainable development;meanwhile,plant oil has plentiful resources,and its products are inherently biodegradable,so it has a broad potential application in daily life and the medical field.Through the review of the synthesis of plant-oil-based plastics,and several simple analyses of scope,limitations and the feasibility of the materials,those will contribute to the research of plant-oil-based plastics in the future.

  6. 转基因植物疫苗的最新研究进展%The Latest Research Progress on Transgenic Plant Vaccines

    Institute of Scientific and Technical Information of China (English)

    周岩; 赵茜; 何男男; 袁重要

    2013-01-01

    随着分子生物学技术与重组DNA技术的不断发展、基因工程疫苗研究的不断深入,传统疫苗体现出诸多缺陷.因此,利用植物基因工程方法开发新疫苗逐渐成为疫苗研究的重点.目前,在转基因植物中表达的主要有大肠杆菌热敏肠毒素B亚单位、乙型肝炎病毒表面抗原、诺沃克病毒外壳蛋白、口蹄疫病毒、狂犬病病毒糖蛋白、变异链球菌表面蛋白和艾滋病病毒抗原等10多种疫苗.与传统疫苗相比,转基因植物疫苗具有价廉、安全、有效、易于运输与保存等优点,因而成为现代疫苗学研究的一个热点.文章综述了国内外植物基因工程疫苗的现状及最新研究进展,对其存在的问题及对策进行讨论,对其发展前景进行展望.%Along with the development of molecular biology technology and the recombinant DNA technology, and with the deepening research of genetic engineering vaccine, traditional vaccine has already reflected many defects, using the technology of plant genetic engineering to develop new vaccine has become the focus of vaccine research gradually. This paper introduced the definition of transgenic plant vaccine firstly, and summarized its advantages. Compared with traditional vaccine, the transgenic plant vaccine was cheaper, safer, more efficient, easier to be transported and stored. Therefore, transgenic plant vaccine was becoming a hot issue in vaccinology. At present, the number of transgenic plant vaccine found in foreign countries more than 10 kinds. Also the paper reviewed transgenic plant vaccine's present situation and mainly introduced the latest research progress, including its immune protection effect. Some issues and countermeasures were discussed with regard to the further development of plant-based on vaccine, as well as prospect of studies on plant-based vaccine were also introduced.

  7. Refurbish power supply/distribution system, Phase 2, Y-12 Plant, Oak Ridge. Progress status report number 51

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-30

    This is a report on the phase 2 of refurbishing power supply/distribution system at Y-12 Plant, Oak Ridge, TN. The report topics include accomplishments by work breakdown structure (WBS) identifier, identification of items issued and items received, past due items, items requested, a milestone schedule by WBS and including a drawing list showing percent complete, and conference summaries.

  8. Structural studies of complex carbohydrates of plant cell walls. Progress report, June 15, 1992--June 14, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, A.G.

    1994-10-01

    This report contains the abstracts of fourteen papers published, in press, or in preparation reporting on research activities to investigate the structure, as well as the function of cell walls in plants. This document also contains research on methods to determine the structure of complex carbohydrates of the cell walls.

  9. Mitochondria: energy converters for organization of life; Mitochondrien: Energiewandler fuer die Organisation des Lebendigen

    Energy Technology Data Exchange (ETDEWEB)

    Neupert, W. [Universitaet Muenchen (Germany). Inst. fuer Physiologische Chemie

    2004-07-01

    Maintenance and reproduction of life needs permanent supply of energy. Plants are able to convert the energy of sunlight into chemical energy. Other organisms have to take up and digest nutrients in order to generate usable forms of energy. Many types of bacteria and virtually all higher organisms use oxidation of compounds derived from nutrients as the major pathway for energy transduction. In this way, two forms of energy are produced which promote virtually all activities of animal life: First, a concentration gradient of protons across biological membranes is generated, which represents a proton motive force (PMF). In a second reaction, the energy of the PMF is stored in the molecule adenosine triphosphate (ATP), the >>universal energy coin<< for a myriad of chemical reactions within the cell. The two processes, generation of PMF powered by oxidation, and synthesis of ATP are usually coupled to each other, only for a few cellular processes PMF can be used directly. The overall reaction is called oxidative phosphorylation. It takes place in special cell organelles, the mitochondria. These small bodies are often referred to as the >>power plants of the cell<<. The term is entirely appropriate as e.g. the mitochondria of mankind generate energy of several hundred gigawatt per year. The mitochondria provide this energy to the rest of the cell. During evolution mitochondria have arisen by endosymbiosis of {alpha}-proteobacteria in precursors of the current eukaryotic cells. The bacteria brought along the enzymatic machinery of oxidative phosphorylation. The generation of the proton gradient across the inner membrane of mitochondria and the conversion of energy contained therein into energy stored in ATP are performed by a series of >>molecular machines<<. Such molecular machines are composed of a large number of different proteins and cofactors. They display amazing similarities to machines constructed by engineers in our technical world. (orig.)

  10. Selective superoxide generation within mitochondria by the targeted redox cycler MitoParaquat.

    Science.gov (United States)

    Robb, Ellen L; Gawel, Justyna M; Aksentijević, Dunja; Cochemé, Helena M; Stewart, Tessa S; Shchepinova, Maria M; Qiang, He; Prime, Tracy A; Bright, Thomas P; James, Andrew M; Shattock, Michael J; Senn, Hans M; Hartley, Richard C; Murphy, Michael P

    2015-12-01

    Superoxide is the proximal reactive oxygen species (ROS) produced by the mitochondrial respiratory chain and plays a major role in pathological oxidative stress and redox signaling. While there are tools to detect or decrease mitochondrial superoxide, none can rapidly and specifically increase superoxide production within the mitochondrial matrix. This lack impedes progress, making it challenging to assess accurately the roles of mitochondrial superoxide in cells and in vivo. To address this unmet need, we synthesized and characterized a mitochondria-targeted redox cycler, MitoParaquat (MitoPQ) that comprises a triphenylphosphonium lipophilic cation conjugated to the redox cycler paraquat. MitoPQ accumulates selectively in the mitochondrial matrix driven by the membrane potential. Within the matrix, MitoPQ produces superoxide by redox cycling at the flavin site of complex I, selectively increasing superoxide production within mitochondria. MitoPQ increased mitochondrial superoxide in isolated mitochondria and cells in culture ~a thousand-fold more effectively than untargeted paraquat. MitoPQ was also more toxic than paraquat in the isolated perfused heart and in Drosophila in vivo. MitoPQ enables the selective generation of superoxide within mitochondria and is a useful tool to investigate the many roles of mitochondrial superoxide in pathology and redox signaling in cells and in vivo.

  11. Morphological abnormalities in mitochondria of the skin of patients with sporadic amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Gabriel E. Rodríguez

    2012-01-01

    Full Text Available OBJECTIVES: Mitochondrial dysfunction has been reported in the central nervous system, hepatocytes and peripheral blood lymphocytes from patients with sporadic amyotrophic lateral sclerosis (SALS. However, the status of skin mitochondria has not been reported, in spite of the fact that SALS patients present skin abnormalities. The objective of the present study was to compare mitochondrial ultrastructural parameters in keratinocytes from patients with SALS and healthy controls. METHODS: Our study was based on the analysis of 112 skin mitochondria from 5 SALS patients and 99 organelles from 4 control subjects by electron microscopy. RESULTS: Computerized image analysis showed that mitochondrial major axis length, area and perimeter of the organelle were significantly smaller in SALS respect of healthy control subjects. Morphologically, SALS mitochondria presented cristolysis and breakage of the outer membrane. CONCLUSIONS: Mitochondrial dysfunction in the skin may possibly reflect changes occurring in mitochondria of the central nervous system. The analysis of mitochondrial morphology in this tissue may be of value to follow disease progression and, eventually, the effectiveness of current therapies for SALS.

  12. Mitochondrial translocation of EGFR regulates mitochondria dynamics and promotes metastasis in NSCLC.

    Science.gov (United States)

    Che, Ting-Fang; Lin, Ching-Wen; Wu, Yi-Ying; Chen, Yu-Ju; Han, Chia-Li; Chang, Yih-leong; Wu, Chen-Tu; Hsiao, Tzu-Hung; Hong, Tse-Ming; Yang, Pan-Chyr

    2015-11-10

    Dysfunction of the mitochondria is well-known for being associated with cancer progression. In the present study, we analyzed the mitochondria proteomics of lung cancer cell lines with different invasion abilities and found that EGFR is highly expressed in the mitochondria of highly invasive non-small-cell lung cancer (NSCLC) cells. EGF induces the mitochondrial translocation of EGFR; further, it leads to mitochondrial fission and redistribution in the lamellipodia, upregulates cellular ATP production, and enhances motility in vitro and in vivo. Moreover, EGFR can regulate mitochondrial dynamics by interacting with Mfn1 and disturbing Mfn1 polymerization. Overexpression of Mfn1 reverses the phenotypes resulting from EGFR mitochondrial translocation. We show that the mitochondrial EGFR expressions are higher in paired samples of the metastatic lymph node as compared with primary lung tumor and are inversely correlated with the overall survival in NSCLC patients. Therefore, our results demonstrate that besides the canonical role of EGFR as a receptor tyrosine, the mitochondrial translocation of EGFR may enhance cancer invasion and metastasis through regulating mitochondria dynamics.

  13. Biased inheritance of mitochondria during asymmetric cell division in the mouse oocyte

    Science.gov (United States)

    Dalton, Caroline M.; Carroll, John

    2013-01-01

    Summary A fundamental rule of cell division is that daughter cells inherit half the DNA complement and an appropriate proportion of cellular organelles. The highly asymmetric cell divisions of female meiosis present a different challenge because one of the daughters, the polar body, is destined to degenerate, putting at risk essential maternally inherited organelles such as mitochondria. We have therefore investigated mitochondrial inheritance during the meiotic divisions of the mouse oocyte. We find that mitochondria are aggregated around the spindle by a dynein-mediated mechanism during meiosis I, and migrate together with the spindle towards the oocyte cortex. However, at cell division they are not equally segregated and move instead towards the oocyte-directed spindle pole and are excluded from the polar body. We show that this asymmetrical inheritance in favour of the oocyte is not caused by bias in the spindle itself but is dependent on an intact actin cytoskeleton, spindle–cortex proximity, and cell cycle progression. Thus, oocyte-biased inheritance of mitochondria is a variation on rules that normally govern organelle segregation at cell division, and ensures that essential maternally inherited mitochondria are retained to provide ATP for early mammalian development. PMID:23659999

  14. Mitochondria-Targeted Antioxidants: Future Perspectives in Kidney Ischemia Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Aleksandra Kezic

    2016-01-01

    Full Text Available Kidney ischemia/reperfusion injury emerges in various clinical settings as a great problem complicating the course and outcome. Ischemia/reperfusion injury is still an unsolved puzzle with a great diversity of investigational approaches, putting the focus on oxidative stress and mitochondria. Mitochondria are both sources and targets of ROS. They participate in initiation and progression of kidney ischemia/reperfusion injury linking oxidative stress, inflammation, and cell death. The dependence of kidney proximal tubule cells on oxidative mitochondrial metabolism makes them particularly prone to harmful effects of mitochondrial damage. The administration of antioxidants has been used as a way to prevent and treat kidney ischemia/reperfusion injury for a long time. Recently a new method based on mitochondria-targeted antioxidants has become the focus of interest. Here we review the current status of results achieved in numerous studies investigating these novel compounds in ischemia/reperfusion injury which specifically target mitochondria such as MitoQ, Szeto-Schiller (SS peptides (Bendavia, SkQ1 and SkQR1, and superoxide dismutase mimics. Based on the favorable results obtained in the studies that have examined myocardial ischemia/reperfusion injury, ongoing clinical trials investigate the efficacy of some novel therapeutics in preventing myocardial infarct. This also implies future strategies in preventing kidney ischemia/reperfusion injury.

  15. Dendritic mitochondria reach stable positions during circuit development.

    Science.gov (United States)

    Faits, Michelle C; Zhang, Chunmeng; Soto, Florentina; Kerschensteiner, Daniel

    2016-01-07

    Mitochondria move throughout neuronal dendrites and localize to sites of energy demand. The prevailing view of dendritic mitochondria as highly motile organelles whose distribution is continually adjusted by neuronal activity via Ca(2+)-dependent arrests is based on observations in cultured neurons exposed to artificial stimuli. Here, we analyze the movements of mitochondria in ganglion cell dendrites in the intact retina. We find that whereas during development 30% of mitochondria are motile at any time, as dendrites mature, mitochondria all but stop moving and localize stably to synapses and branch points. Neither spontaneous nor sensory-evoked activity and Ca(2+) transients alter motility of dendritic mitochondria; and pathological hyperactivity in a mouse model of retinal degeneration elevates rather than reduces motility. Thus, our findings indicate that dendritic mitochondria reach stable positions during a critical developmental period of high motility, and challenge current views about the role of activity in regulating mitochondrial transport in dendrites.

  16. An Overview on the Progress of Chemical Constituents and Bioactivities of Plants in Urticaceae during 2000-2010

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; YANG Hong-xing; TENG Yong-zhen; YUAN Pei; TIAN Rui; LIAO Chun-bi

    2011-01-01

    Utticaceae includes about 1300 species in 47 genera which largely spread in wet tropical regions,and 341 species in 25 genera are in China.Some species are used in Chinese folk medicine.So far,studies on chemistry and pharmacology of Urticaceous plants are mainly focused on nettle of Urtica L.In this review,the chemical researches on 35 new compounds and related pharmacological effects of the plants in Urticaceae reported during2000-2010 are described.The 35 new compounds belong to the classes of lignan,secolignan,norlignan,flavonoid,alkaloid,sesquiterpenoid,triterpenoid,sterol,and sphingolipid.The main bioactivities include cytotoxic,antitumor,antimicrobial,antifungal,anti-BPH,anti-HIV,antidiabetic,hypolipidemic,5α-reductase inhibitory,hair regrowth promotion,and anti-oxidative activities.

  17. Import of proteins into isolated yeast mitochondria.

    Science.gov (United States)

    Peleh, Valentina; Ramesh, Ajay; Herrmann, Johannes M

    2015-01-01

    Mitochondria are essential organelles of eukaryotic cells. The vast majority of mitochondrial proteins is encoded within the nuclear genome and translocated into various mitochondrial compartments after translation in the cytosol as preproteins. Even in rather primitive eukaryotes like yeasts, there are 700-1,000 different proteins that need to be recognized in the cytosol, directed to the protein translocases in the two mitochondrial membranes and sorted to their appropriate mitochondrial subcompartment. In vitro reconstituted import systems have proved to be important tools to study these processes in detail. Using isolated mitochondria and radioactively labeled precursor proteins, it was possible to identify several import machineries and pathways consisting of a large number of components during the last few decades.

  18. Cardiovascular Disease, Mitochondria, and Traditional Chinese Medicine

    Directory of Open Access Journals (Sweden)

    Jie Wang

    2015-01-01

    Full Text Available Recent studies demonstrated that mitochondria play an important role in the cardiovascular system and mutations of mitochondrial DNA affect coronary artery disease, resulting in hypertension, atherosclerosis, and cardiomyopathy. Traditional Chinese medicine (TCM has been used for thousands of years to treat cardiovascular disease, but it is not yet clear how TCM affects mitochondrial function. By reviewing the interactions between the cardiovascular system, mitochondrial DNA, and TCM, we show that cardiovascular disease is negatively affected by mutations in mitochondrial DNA and that TCM can be used to treat cardiovascular disease by regulating the structure and function of mitochondria via increases in mitochondrial electron transport and oxidative phosphorylation, modulation of mitochondrial-mediated apoptosis, and decreases in mitochondrial ROS. However further research is still required to identify the mechanism by which TCM affects CVD and modifies mitochondrial DNA.

  19. Nuclear apoptosis induced by isolated mitochondria

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    We isolated and purified mitochondria from mouse livers and spinach leaves. When added into egg extracts of Xenopus laevis, they caused nuclei of mouse liver to undergo apoptotic changes. Chromatin condensation, margination and DNA ladder were observed. After incubating isolated mitochondria in some hypotonic solutions, and centrifuging these mixtures at high speed, we got mitochondrial supernatants. It was found that in the absence of cytosolic factor, the supernatant alone was able to induce apoptotic changes in nuclei. The effective components were partly of protein. DNA fragmentation was partly inhibited by caspase inhibitors AC-DEVD-CHO and AC-YVADCHO. Meanwhile, caspase inhibitors fully blocked chromatin condensation. Primary characterization of the nuclear endonuclease(s) induced by mitochondrial supernatants was also conducted. It was found that this endonuclease is different from endonuclease G, cytochrome c-induced nuclease, or Ca2+-activated endonuclease.

  20. The curious case of vanishing mitochondria

    Directory of Open Access Journals (Sweden)

    Anna Karnkowska

    2016-09-01

    Full Text Available Due to their involvement in the energy metabolism, mitochondria are essential for most eukaryotic cells. Microbial eukaryotes living in low oxygen environments possess reduced forms of mitochondria, namely mitochondrion-related organelles (MROs. These do not produce ATP by oxidative phosphorylation on their membranes and some do not produce ATP at all. Still, they are indispensable because of other essential functions such as iron-sulphur (Fe-S cluster assembly. Recently, the first microbial eukaryote with neither mitochondrion nor MRO was characterized – Monocercomonoides sp. Genome and transcriptome sequencing of Monocercomonoides revealed that it lacks all hallmark mitochondrial proteins. Crucially, the essential mitochondrial pathway for the Fe-S cluster assembly (ISC was replaced by a bacterial sulphur mobilization (SUF system. The discovery of such bona fide amitochondriate eukaryote broadens our knowledge about the diversity and plasticity of eukaryotic cells and provides a substantial contribution to our understanding of eukaryotic cell evolution.

  1. The curious case of vanishing mitochondria

    Science.gov (United States)

    Karnkowska, Anna; Hampl, Vladimír

    2016-01-01

    Due to their involvement in the energy metabolism, mitochondria are essential for most eukaryotic cells. Microbial eukaryotes living in low oxygen environments possess reduced forms of mitochondria, namely mitochondrion-related organelles (MROs). These do not produce ATP by oxidative phosphorylation on their membranes and some do not produce ATP at all. Still, they are indispensable because of other essential functions such as iron-sulphur (Fe-S) cluster assembly. Recently, the first microbial eukaryote with neither mitochondrion nor MRO was characterized - Monocercomonoides sp. Genome and transcriptome sequencing of Monocercomonoides revealed that it lacks all hallmark mitochondrial proteins. Crucially, the essential mitochondrial pathway for the Fe-S cluster assembly (ISC) was replaced by a bacterial sulphur mobilization (SUF) system. The discovery of such bona fide amitochondriate eukaryote broadens our knowledge about the diversity and plasticity of eukaryotic cells and provides a substantial contribution to our understanding of eukaryotic cell evolution. PMID:28357316

  2. Insulin signaling meets mitochondria in metabolism.

    Science.gov (United States)

    Cheng, Zhiyong; Tseng, Yolanda; White, Morris F

    2010-10-01

    Insulin controls nutrient and metabolic homeostasis via the IRS-PI3K-AKT signaling cascade that targets FOXO1 and mTOR. Mitochondria, as the prime metabolic platform, malfunction during insulin resistance in metabolic diseases. However, the molecular link between insulin resistance and mitochondrial dysfunction remains undefined. Here we review recent studies on insulin action and the mechanistic association with mitochondrial metabolism. These studies suggest that insulin signaling underpins mitochondrial electron transport chain integrity and activity by suppressing FOXO1/HMOX1 and maintaining the NAD(+)/NADH ratio, the mediator of the SIRT1/PGC1α pathway for mitochondrial biogenesis and function. Mitochondria generate moderately reactive oxygen species (ROS) and enhance insulin sensitivity upon redox regulation of protein tyrosine phosphatase and insulin receptor. However, chronic exposure to high ROS levels could alter mitochondrial function and thereby cause insulin resistance.

  3. Fluoroacetylcarnitine: metabolism and metabolic effects in mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Bremer, J.; Davis, E.J.

    1973-01-01

    The metabolism and metabolic effects of fluoroacetylcarnitine have been investigated. Carnitineacetyltransferase transfers the fluoro-acetyl group of fluoroacetylcarnitine nearly as rapidly to CoA as the acetyl group of acetylcarnitine. Fluorocitrate is then formed by citrate synthase, but this second reaction is relatively slow. The fluorocitrate formed intramitochondrially inhibits the metabolism of citrate. In heart and skeletal muscle mitochondria the accumulated citrate inhibits citrate synthesis and the ..beta..-oxidation of fatty acids. Free acetate is formed, presumably because accumulated acetyl-CoA is hydrolyzed. In liver mitochondria the accumulation of citrate leads to a relatively increased rate of ketogenesis. Increased ketogenesis is obtained also upon the addition of citrate to the reaction mixture.

  4. Toxic effects of carvacrol, caryophyllene oxide, and ascaridole from essential oil of Chenopodium ambrosioides on mitochondria.

    Science.gov (United States)

    Monzote, Lianet; Stamberg, Werner; Staniek, Katrin; Gille, Lars

    2009-11-01

    Chenopodium ambrosioides have been used for centuries in the Americas as a popular remedy for parasitic diseases. The essential oil of this plant possesses anthelmintic activity and is still used in some regions to treat parasitosis and leishmaniasis. However, the Chenopodium oil caused also some fatalities, leading to its commercial disuse. In this work, we studied the mechanism of toxicity of the essential oil and its major pure ingredients (carvacrol, caryophyllene oxide, and ascaridole, which was synthesized from alpha-terpinene) with respect to mammalian cells and mitochondria. We observed that all products, but especially caryophyllene oxide, inhibited the mitochondrial electron transport chain. This effect for carvacrol and caryophyllene oxide was mediated via direct complex I inhibition. Without Fe2+, ascaridole was less toxic to mammalian mitochondria than other major ingredients. However, evidence on the formation of carbon-centered radicals in the presence of Fe2+ was obtained by ESR spin-trapping. Furthermore, it was shown that Fe2+ potentiated the toxicity of ascaridole on oxidative phosphorylation of rat liver mitochondria. The increase of the alpha-tocopherol quinone/alpha-tocopherol ratio under these conditions indicated the initiation of lipid peroxidation by Fe2+-mediated ascaridole cleavage. Further ESR spin-trapping experiments demonstrated that in addition to Fe2+, reduced hemin, but not mitochondrial cytochrome c can activate ascaridole, explaining why ascaridole in peritoneal macrophages from BALB/c mice exhibited a higher toxicity than in isolated mitochondria.

  5. Recent progress in the understanding of tissue culture-induced genome level changes in plants and potential applications.

    Science.gov (United States)

    Neelakandan, Anjanasree K; Wang, Kan

    2012-04-01

    In vitro cell and tissue-based systems have tremendous potential in fundamental research and for commercial applications such as clonal propagation, genetic engineering and production of valuable metabolites. Since the invention of plant cell and tissue culture techniques more than half a century ago, scientists have been trying to understand the morphological, physiological, biochemical and molecular changes associated with tissue culture responses. Establishment of de novo developmental cell fate in vitro is governed by factors such as genetic make-up, stress and plant growth regulators. In vitro culture is believed to destabilize the genetic and epigenetic program of intact plant tissue and can lead to chromosomal and DNA sequence variations, methylation changes, transposon activation, and generation of somaclonal variants. In this review, we discuss the current status of understanding the genomic and epigenomic changes that take place under in vitro conditions. It is hoped that a precise and comprehensive knowledge of the molecular basis of these variations and acquisition of developmental cell fate would help to devise strategies to improve the totipotency and embryogenic capability in recalcitrant species and genotypes, and to address bottlenecks associated with clonal propagation.

  6. Acid rain research program. Annual progress report, July 1976--September 1977. [Effects on plants and soil microbiological processes

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L.S.; Francis, A.J.; Raynor, G.S.

    1977-12-01

    Experiments were carried out and chemical aspects of ambient precipitation were determined using a sequential precipitation collector for the period July 1976 through September 1977. A related report provides experimental details. In experiments with plants, experiments were aimed to document: the foliar response of six clones of hybrid poplar to simulated acid rain; effects of buffered solutions and various anions on vegetative and sexual development of gametophytes of the fern (Pteridium aquilinum) and the acid-sensitive steps of symbiotic nitrogen fixation of the garden pea (Pisum sativum). After five 6 min daily exposures to simulated rain of pH 2.7, up to 10 percent of the leaf area of some poplar clones was injured. Lesions developed mostly near stomata and vascular tissue as shown with other plant species. Acidic solutions have a marked effect on sperm motility and fertilization (sexual reproduction) of bracken fern. Since sexual reproduction of ferns is very sensitive to mildly acidic conditions under laboratory conditions, experiments are planned to view the response of sexual stages of other plant species. Nodulation and symbiotic nitrogen fixation in Pisum is very sensitive to nutrient solution acidity. Specific isolates of Rhizobium bacteria are used and the medium pH can be maintained rigidly. In experiments to determine the effects of excess acidity on soil microbiological processes, the rate of denitrification may be slowed so drastically that increases of N/sub 2/O in the atmosphere may result with a subsequent reduction in soil nitrogen levels.

  7. Novel cell-penetrating peptide targeting mitochondria.

    Science.gov (United States)

    Cerrato, Carmine Pasquale; Pirisinu, Marco; Vlachos, Efstathios Nikolaos; Langel, Ülo

    2015-11-01

    Cell-penetrating peptides (CPPs) are short, nontoxic peptides with cationic and/or amphipathic properties able to cross the cellular membrane. CPPs are used for the delivery of a wide variety of cargoes, such as proteins, oligonucleotides, and therapeutic molecules. The aim of the present study was to synthesize unusually small novel CPPs targeting mitochondria based on the Szeto-Schiller peptide (SS-31) to influence intramitochondrial processes and to improve the biologic effects. All the peptides used were synthesized manually using 9-fluorenylmethyloxycarbonyl chemistry. In the first part of the study, HeLa 705, U87, and bEnd.3 cells were used as in vitro delivery model. Cells were incubated for 24 h at 37°C and 5% CO2 with different concentrations of our peptides. Cell proliferation assay was performed to evaluate cell viability. Biologic effects such as mitochondrial membrane potential and antioxidant activity were evaluated. H2O2 was used as positive control. Uptake studies were performed using peptides conjugated with 5(6)-carboxyfluorescein (FAM). Fluorescent microscopy was used to determine presence and localization of peptides into the cells. Isolated mitochondria from pretreated cells and mitochondria treated after isolation were used to confirm the targeting ability of the peptide. Uptake of FAM alone was used as negative control. Microscopy studies confirmed the ability of peptides to penetrate cell. Localization analysis showed increase in uptake by 35% compared with SS-31. Mitochondrial CPP 1 (mtCPP-1) had no effect on mitochondrial membrane potential and prevented reactive oxygen species formation in bEnd.3 cells by 2-fold compared with SS-31. No cytotoxicity was observed even at high concentration (100 µM). These data suggest that mtCPP-1 is a mitochondrial CPP and protect mitochondria from oxidative damage due to its own antioxidant activities. © FASEB.

  8. Cardiac mitochondria exhibit dynamic functional clustering

    Directory of Open Access Journals (Sweden)

    Felix Tobias Kurz

    2014-09-01

    Full Text Available Multi-oscillatory behavior of mitochondrial inner membrane potential ΔΨm in self-organized cardiac mitochondrial networks can be triggered by metabolic or oxidative stress. Spatio-temporal analyses of cardiac mitochondrial networks have shown that mitochondria are heterogeneously organized in synchronously oscillating clusters in which the mean cluster frequency and size are inversely correlated, thus suggesting a modulation of cluster frequency through local inter-mitochondrial coupling. In this study, we propose a method to examine the mitochondrial network's topology through quantification of its dynamic local clustering coefficients. Individual mitochondrial ΔΨm oscillation signals were identified for each cardiac myocyte and cross-correlated with all network mitochondria using previously described methods (Kurz et al., 2010. Time-varying inter-mitochondrial connectivity, defined for mitochondria in the whole network whose signals are at least 90% correlated at any given time point, allowed considering functional local clustering coefficients. It is shown that mitochondrial clustering in isolated cardiac myocytes changes dynamically and is significantly higher than for random mitochondrial networks that are constructed using the Erdös-Rényi model based on the same sets of vertices. The network's time-averaged clustering coefficient for cardiac myocytes was found to be 0.500 ± 0.051 (N=9 versus 0.061 ± 0.020 for random networks, respectively. Our results demonstrate that cardiac mitochondria constitute a network with dynamically connected constituents whose topological organization is prone to clustering. Cluster partitioning in networks of coupled oscillators has been observed in scale-free and chaotic systems and is therefore in good agreement with previous models of cardiac mitochondrial networks (Aon et al., 2008.

  9. Insulin signaling meets mitochondria in metabolism

    OpenAIRE

    Cheng, Zhiyong; Tseng, Yolanda; White, Morris F.

    2010-01-01

    Insulin controls nutrient and metabolic homeostasis via the IRS–PI3K–AKT signaling cascade that targets FOXO1 and mTOR. Mitochondria, as the prime metabolic platform, malfunction during insulin resistance in metabolic diseases. However, the molecular link between insulin resistance and mitochondrial dysfunction remains undefined. Here we review recent studies on insulin action and the mechanistic association with mitochondrial metabolism. These studies suggest that insulin signaling underpins...

  10. Possible in-vessel corium progression way in the Unit 1 of Fukushima Dai-ichi nuclear power plant using a phenomenological analysis

    Directory of Open Access Journals (Sweden)

    Payot Frédéric

    2015-01-01

    Full Text Available In the field of severe accident, the description of corium progression events is mainly carried out by using integral calculation codes. However, these tools are usually based on bounding assumptions because of high complexity of phenomena. The limitations associated with bounding situations ([J.M. Seiler, B. Tourniaire, A phenomenological analysis of melt progression in the lower head of a pressurized water reactor, Nucl. Eng. Des. 268, 87 (2014] e.g. steady state situations and instantaneous whole core relocation in the lower head led CEA to develop an alternative approach in order to improve the phenomenological description of melt progression. The methodology used to describe the corium progression was designed to cover the accidental situations from the core meltdown to the molten core concrete interaction. This phenomenological approach is based on available data (including learnings from TMI2, on physical models and knowledge about the corium behavior. It provides emerging trends and best estimated intermediate situations. As different phenomena are unknown, but strongly coupled, uncertainties at large scale for the reactor application must be taken into account. Furthermore, the analysis is complicated by the fact that these configurations are most probably three dimensional, all the more so because 3D effects are expected to have significant consequences for the corium progression and the resulting vessel failure. Such an analysis of the in-vessel melt progression was carried out for the Unit 1 of the Fukushima Dai-ichi nuclear power plant. The core uncovering kinetics governs the core degradation and impacts the appearance of the first molten corium inside the core. The initial conditions used to carry out this analysis are based on available results derived from codes like MELCOR calculation code [R. Ganntt, D. Kalinich, J. Cardoni, J. Phillips, A. Goldmann, S. Pickering, M. Francis, K. Robb, L. Ott, D. Wang, C. Smith, S. St. Germain

  11. Vps13-Mcp1 interact at vacuole-mitochondria interfaces and bypass ER-mitochondria contact sites.

    Science.gov (United States)

    John Peter, Arun T; Herrmann, Beatrice; Antunes, Diana; Rapaport, Doron; Dimmer, Kai Stefan; Kornmann, Benoît

    2017-10-02

    Membrane contact sites between endoplasmic reticulum (ER) and mitochondria, mediated by the ER-mitochondria encounter structure (ERMES) complex, are critical for mitochondrial homeostasis and cell growth. Defects in ERMES can, however, be bypassed by point mutations in the endosomal protein Vps13 or by overexpression of the mitochondrial protein Mcp1. How this bypass operates remains unclear. Here we show that the mitochondrial outer membrane protein Mcp1 functions in the same pathway as Vps13 by recruiting it to mitochondria and promoting its association to vacuole-mitochondria contacts. Our findings support a model in which Mcp1 and Vps13 work as functional effectors of vacuole-mitochondria contact sites, while tethering is mediated by other factors, including Vps39. Tethered and functionally active vacuole-mitochondria interfaces then compensate for the loss of ERMES-mediated ER-mitochondria contact sites. © 2017 John Peter et al.

  12. Molecular studies of functional aspects of plant mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Siedow, J.N.

    1992-03-03

    The goal of this research is to characterize the mechanism by which a protein encoded by mitochondrial genome of cms-T maize (URF13) interacts with a family of the compounds produced by certain fungi (T-toxins) to permeabilize biological membranes. The research carried out during the current funding period has focused on the structure of URF13, and the results support the validity of the three-helix model of URF13 and provide direct evidence for the oligomeric nature of at least some of the URF13 molecules in the membrane. In addition, the toxin binding studies have provided insight into the dynamic nature of the T-toxin:URF13 interaction and the extent to which Asp-39 is crucial to the interaction that leads to membrane pore formation. Additional knowledge of the structure of URF13 is needed if the nature of the interaction between URF13 and T-toxin to produce a hydrophilic pore within the membrane is to ultimately be understood.

  13. Role of mitochondria in parvovirus pathology.

    Directory of Open Access Journals (Sweden)

    Jonna Nykky

    Full Text Available Proper functioning of the mitochondria is crucial for the survival of the cell. Viruses are able to interfere with mitochondrial functions as they infect the host cell. Parvoviruses are known to induce apoptosis in infected cells, but the role of the mitochondria in parvovirus induced cytopathy is only partially known. Here we demonstrate with confocal and electron microscopy that canine parvovirus (CPV associated with the mitochondrial outer membrane from the onset of infection. During viral entry a transient depolarization of the mitochondrial transmembrane potential and increase in ROS level was detected. Subsequently, mitochondrial homeostasis was normalized shortly, as detected by repolarization of the mitochondrial membrane and decrease of ROS. Indeed, activation of cell survival signalling through ERK1/2 cascade was observed early in CPV infected cells. At 12 hours post infection, concurrent with the expression of viral non-structural protein 1, damage to the mitochondrial structure and depolarization of its membrane were apparent. Results of this study provide additional insight of parvovirus pathology and also more general information of virus-mitochondria association.

  14. Connecting Mitochondria, Metabolism, and Stem Cell Fate.

    Science.gov (United States)

    Wanet, Anaïs; Arnould, Thierry; Najimi, Mustapha; Renard, Patricia

    2015-09-01

    As sites of cellular respiration and energy production, mitochondria play a central role in cell metabolism. Cell differentiation is associated with an increase in mitochondrial content and activity and with a metabolic shift toward increased oxidative phosphorylation activity. The opposite occurs during reprogramming of somatic cells into induced pluripotent stem cells. Studies have provided evidence of mitochondrial and metabolic changes during the differentiation of both embryonic and somatic (or adult) stem cells (SSCs), such as hematopoietic stem cells, mesenchymal stem cells, and tissue-specific progenitor cells. We thus propose to consider those mitochondrial and metabolic changes as hallmarks of differentiation processes. We review how mitochondrial biogenesis, dynamics, and function are directly involved in embryonic and SSC differentiation and how metabolic and sensing pathways connect mitochondria and metabolism with cell fate and pluripotency. Understanding the basis of the crosstalk between mitochondria and cell fate is of critical importance, given the promising application of stem cells in regenerative medicine. In addition to the development of novel strategies to improve the in vitro lineage-directed differentiation of stem cells, understanding the molecular basis of this interplay could lead to the identification of novel targets to improve the treatment of degenerative diseases.

  15. Mitochondria and the evolutionary roots of cancer

    Science.gov (United States)

    Davila, Alfonso F.; Zamorano, Pedro

    2013-04-01

    Cancer disease is inherent to, and widespread among, metazoans. Yet, some of the hallmarks of cancer such as uncontrolled cell proliferation, lack of apoptosis, hypoxia, fermentative metabolism and free cell motility (metastasis) are akin to a prokaryotic lifestyle, suggesting a link between cancer disease and evolution. In this hypothesis paper, we propose that cancer cells represent a phenotypic reversion to the earliest stage of eukaryotic evolution. This reversion is triggered by the dysregulation of the mitochondria due to cumulative oxidative damage to mitochondrial and nuclear DNA. As a result, the phenotype of normal, differentiated cells gradually reverts to the phenotype of a facultative anaerobic, heterotrophic cell optimized for survival and proliferation in hypoxic environments. This phenotype matches the phenotype of the last eukaryotic common ancestor (LECA) that resulted from the endosymbiosis between an α-proteobacteria (which later became the mitochondria) and an archaebacteria. As such, the evolution of cancer within one individual can be viewed as a recapitulation of the evolution of the eukaryotic cell from fully differentiated cells to LECA. This evolutionary model of cancer is compatible with the current understanding of the disease, and explains the evolutionary basis for most of the hallmarks of cancer, as well as the link between the disease and aging. It could also open new avenues for treatment directed at reestablishing the synergy between the mitochondria and the cancerous cell.

  16. A cannabinoid link between mitochondria and memory.

    Science.gov (United States)

    Hebert-Chatelain, Etienne; Desprez, Tifany; Serrat, Román; Bellocchio, Luigi; Soria-Gomez, Edgar; Busquets-Garcia, Arnau; Pagano Zottola, Antonio Christian; Delamarre, Anna; Cannich, Astrid; Vincent, Peggy; Varilh, Marjorie; Robin, Laurie M; Terral, Geoffrey; García-Fernández, M Dolores; Colavita, Michelangelo; Mazier, Wilfrid; Drago, Filippo; Puente, Nagore; Reguero, Leire; Elezgarai, Izaskun; Dupuy, Jean-William; Cota, Daniela; Lopez-Rodriguez, Maria-Luz; Barreda-Gómez, Gabriel; Massa, Federico; Grandes, Pedro; Bénard, Giovanni; Marsicano, Giovanni

    2016-11-24

    Cellular activity in the brain depends on the high energetic support provided by mitochondria, the cell organelles which use energy sources to generate ATP. Acute cannabinoid intoxication induces amnesia in humans and animals, and the activation of type-1 cannabinoid receptors present at brain mitochondria membranes (mtCB1) can directly alter mitochondrial energetic activity. Although the pathological impact of chronic mitochondrial dysfunctions in the brain is well established, the involvement of acute modulation of mitochondrial activity in high brain functions, including learning and memory, is unknown. Here, we show that acute cannabinoid-induced memory impairment in mice requires activation of hippocampal mtCB1 receptors. Genetic exclusion of CB1 receptors from hippocampal mitochondria prevents cannabinoid-induced reduction of mitochondrial mobility, synaptic transmission and memory formation. mtCB1 receptors signal through intra-mitochondrial Gαi protein activation and consequent inhibition of soluble-adenylyl cyclase (sAC). The resulting inhibition of protein kinase A (PKA)-dependent phosphorylation of specific subunits of the mitochondrial electron transport system eventually leads to decreased cellular respiration. Hippocampal inhibition of sAC activity or manipulation of intra-mitochondrial PKA signalling or phosphorylation of the Complex I subunit NDUFS2 inhibit bioenergetic and amnesic effects of cannabinoids. Thus, the G protein-coupled mtCB1 receptors regulate memory processes via modulation of mitochondrial energy metabolism. By directly linking mitochondrial activity to memory formation, these data reveal that bioenergetic processes are primary acute regulators of cognitive functions.

  17. Role of mitochondria in parvovirus pathology.

    Science.gov (United States)

    Nykky, Jonna; Vuento, Matti; Gilbert, Leona

    2014-01-01

    Proper functioning of the mitochondria is crucial for the survival of the cell. Viruses are able to interfere with mitochondrial functions as they infect the host cell. Parvoviruses are known to induce apoptosis in infected cells, but the role of the mitochondria in parvovirus induced cytopathy is only partially known. Here we demonstrate with confocal and electron microscopy that canine parvovirus (CPV) associated with the mitochondrial outer membrane from the onset of infection. During viral entry a transient depolarization of the mitochondrial transmembrane potential and increase in ROS level was detected. Subsequently, mitochondrial homeostasis was normalized shortly, as detected by repolarization of the mitochondrial membrane and decrease of ROS. Indeed, activation of cell survival signalling through ERK1/2 cascade was observed early in CPV infected cells. At 12 hours post infection, concurrent with the expression of viral non-structural protein 1, damage to the mitochondrial structure and depolarization of its membrane were apparent. Results of this study provide additional insight of parvovirus pathology and also more general information of virus-mitochondria association.

  18. Analysis of mitochondria isolated from single cells.

    Science.gov (United States)

    Johnson, Ryan D; Navratil, Marian; Poe, Bobby G; Xiong, Guohua; Olson, Karen J; Ahmadzadeh, Hossein; Andreyev, Dmitry; Duffy, Ciarán F; Arriaga, Edgar A

    2007-01-01

    Bulk studies are not suitable to describe and study cell-to-cell variation, which is of high importance in biological processes such as embryogenesis, tissue differentiation, and disease. Previously, capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) was used to measure the properties of organelles isolated from millions of cells. As such, these bulk measurements reported average properties for the organelles of cell populations. Similar measurements for organelles released from single cells would be highly relevant to describe the subcellular variations among cells. Toward this goal, here we introduce an approach to analyze the mitochondria released from single mammalian cells. Osteosarcoma 143B cells are labeled with either the fluorescent mitochondrion-specific 10-N-nonyl acridine orange (NAO) or via expression of the fluorescent protein DsRed2. Subsequently, a single cell is introduced into the CE-LIF capillary where the organelles are released by a combined treatment of digitonin and trypsin. After this treatment, an electric field is applied and the released organelles electromigrate toward the LIF detector. From an electropherogram, the number of detected events per cell, their individual electrophoretic mobilities, and their individual fluorescence intensities are calculated. The results obtained from DsRed2 labeling, which is retained in intact mitochondria, and NAO labeling, which labels all mitochondria, are the basis for discussion of the strengths and limitations of this single-cell approach.

  19. Mitochondria in anthropology and forensic medicine.

    Science.gov (United States)

    Grzybowski, Tomasz; Rogalla, Urszula

    2012-01-01

    Mitochondria's role in crucial metabolic pathways is probably the first answer which comes to our minds for the question: what do these tiny organelles serve for? However, specific features of their DNA made them extremely useful also in the field of anthropology and forensics. MtDNA analyses became a milestone in the complex task of unraveling earliest human migrations. Evidence provided by these experiments left no doubts on modern humans origins pointing to Africa being our cradle. It also contributed to interpretation of putative ways of our dispersal around Asia and Americas thousands years ago. On the other hand, analysis of mtDNA is well established and valuable tool in forensic genetics. When other definitely more popular markers give no answer on identity, it is the time to employ information carried by mitochondria. This chapter summarizes not only current reports on the role of mitochondria in forensics and reconstruction of modern humans phylogeny, but also calls one's attention to a broad range of difficulties and constraints associated with mtDNA analyses.

  20. Biology of Mitochondria in Neurodegenerative Diseases

    Science.gov (United States)

    Martin, Lee J.

    2012-01-01

    Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS) are the most common human adult-onset neurodegenerative diseases. They are characterized by prominent age-related neurodegeneration in selectively vulnerable neural systems. Some forms of AD, PD, and ALS are inherited, and genes causing these diseases have been identified. Nevertheless, the mechanisms of the neuronal degeneration in these familial diseases, and in the more common idiopathic (sporadic) diseases, are unresolved. Genetic, biochemical, and morphological analyses of human AD, PD, and ALS, as well as their cell and animal models, reveal that mitochondria could have roles in this neurodegeneration. The varied functions and properties of mitochondria might render subsets of selectively vulnerable neurons intrinsically susceptible to cellular aging and stress and the overlying genetic variations. In AD, alterations in enzymes involved in oxidative phosphorylation, oxidative damage, and mitochondrial binding of Aβ and amyloid precursor protein have been reported. In PD, mutations in mitochondrial proteins have been identified and mitochondrial DNA mutations have been found in neurons in the substantia nigra. In ALS, changes occur in mitochondrial respiratory chain enzymes and mitochondrial programmed cell death proteins. Transgenic mouse models of human neurodegenerative disease are beginning to reveal possible principles governing the biology of selective neuronal vulnerability that implicate mitochondria and the mitochondrial permeability transition pore. This chapter reviews several aspects of mitochondrial biology and how mitochondrial pathobiology might contribute to the mechanisms of neurodegeneration in AD, PD, and ALS. PMID:22482456

  1. Research progress of plant monitoring for indoor chemical pollution gases%室内化学污染气体的植物监测研究进展

    Institute of Scientific and Technical Information of China (English)

    鲁敏; 刘顺腾; 赵洁

    2013-01-01

    随着室内装修装饰的大量涌现,室内化学污染物超标现象日趋严重,现代人类已经继第一污染时期—煤烟型污染和第二污染时期—光化学烟雾污染后,进入以室内化学污染为标志的第三污染时期.利用植物监测室内化学污染气体已成为安全有效的监测、控制室内化学污染的重要途径.文章阐述了室内化学污染物的特点、危害及植物监测的作用;从外部数量性状、生理生化指标、综合指标三方面综述了植物对室内化学污染监测的相关研究进展,并对植物监测研究和应用前景做出展望.%With the proliferation of the interior decoration, the phenomenon of exceeding standard of the indoor chemical pollutants is becoming more and more serious, modern human has come into the third pollution period- "indoor chemical pollution" from the first pollution period- "soot pollution" and the second pollution period- "photochemical smoke pollution". Using plants to monitor indoor chemical pollution gases has become a safe and effective way to monitor and control indoor chemical pollution. The paper expounds the characteristics and harm of indoor chemical pollution and the role of plant monitoring, summarizes the research progress of plant monitoring for indoor chemical pollution from external quantitative traits, physiological and biochemical index and comprehensive index, and makes prospect of plant monitoring research and application.

  2. 植物超氧化物歧化酶的研究进展%Research Progress on Plant Superoxide Dismutase

    Institute of Scientific and Technical Information of China (English)

    张宇婷; 高建民; 张琼琳; 张爱东; 王海霞; 孙杰

    2016-01-01

    Plants are always suffered from physiological or non-physiological stress with different degrees in growth and development, which results in the production of numerous ROS affecting normal growth and metabolism of plants and even causing senescence and death. Numerous studies have shown that the superoxide dismutase of plants can exert its unique effect to remove a serious of ROS effectively so as to maintain plant′s ordinary life activities, and it has been widely applied in agriculture, medicine, food and chemical industry. We introduced the distribution, category, physical and chemical properties, physiological functions and progress on research and application of one of the most import members in antioxidant enzyme systems of plants-superoxide dismutase.%植物在生长发育的过程中会受到不同程度的生理或非生理胁迫,导致植物细胞内产生大量活性氧,影响植物正常生长代谢,甚至引起植物衰老死亡。大量研究显示,植物中的超氧化物歧化酶能发挥其独特的功能有效地清除多种活性氧,维持植物正常生命活动,并已经在农业、医疗、食品和化工多个领域得到了应用。就抗氧化酶系统中极其重要的成员———超氧化物歧化酶的分布类别、理化性质、生理功能及相关的研究应用情况进行了概述。

  3. Installation of a stoker-coal preparation plant in Krakow, Poland. Quarterly technical progress report No. 3, November--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Rozelle, P.

    1996-01-01

    This report describes the progress made during this reporting period of a two year project to demonstrate that the air pollution from a traveling grate stoker being used to heat water at a central heating plant in Krakow, Poland can be reduced significantly by (1) substituting the unwashed, unsized coal currently being used with a mechanically cleaned, double-sized stoker fuel and by (2) optimizing the operating parameters of the stoker. It is anticipated that these improvements will prove to be cost effective and hence be adopted by the other central heating plants in Krakow and indeed, throughout Eastern European cities where coal continues to be the primary source of fuel. EFH Coal Company has formed a partnership with two Polish institutions -- MPEC, a central heating company in Krakow, and Naftokrak-Naftobudowa, preparation plant designers and fabricators, for the execution of this effort. The washability data from a 20mm x 0.5mm size fraction of raw coal from the Nikwa Modrejow Mine were evaluated. The data show that the ash content of this coal can be reduced from 34.0 percent to 9.0 percent by washing in a heavy-media cyclone at 1.725 sp.gr.; the actual yield of clean coal would be 63.1 percent. This product would meet compliance limitations of 500 a of SO{sub 2}/GJ. An evaluation of the predicted results that can be expected when washing five different candidate Polish coals shows that compliance products containing less than 640 a SO{sub 2}/GJ and 10 percent ash at attractive yields can be produced by washing the raw coals in a heavy-media cyclone. Discussions with financial institutions regarding the cost of producing a quality stoker coal in Poland and for identifying sources of private capital to help cost share the project continued. The search for markets for utilizing surplus production from the new plant continued.

  4. 植物基质栽培的研究进展%Research Progress of Substrate Culture of Plant

    Institute of Scientific and Technical Information of China (English)

    徐强; 张沛东; 涂忠

    2015-01-01

    基质栽培作为无土栽培的一种,具有病虫害少、节水节肥、栽种灵活、可控性较高等优点,近几十年来在国内外得到了广泛的发展和应用。本文系统总结了栽培基质的材料分类和性状类型,重点论述了陆生植物和水生植物栽培基质的类型和研究现状,比较分析了不同栽培基质的栽培效果,探讨了基质栽培存在的一些问题和局限性,并对今后的研究方向进行了展望,以期为进一步开展海洋高等植物栽培基质的研究提供科学依据。%Substrate culture as one kind of soilless cultures has the advantages such as less disease and pests, saving water and fertilizer, planting flexibly and higher controllability .In the recent decades, it ob-tained wide development and application at home and abroad .In this paper , the material classification and trait type of culture substrates were summerized;the substrate types for terrestrial and aquatic plants and their reseach status were discussed;the culture effects of different substrates were compared and analyzed;some ex-isting problems and boundedness were also discussed .Based on these , the research direction of substrate cul-ture was prospect .It was expected to provide scientific basis for further research on substrates for culture of advanced marine plant .

  5. Extensive fusion of mitochondria in spinal cord motor neurons.

    Directory of Open Access Journals (Sweden)

    Geoffrey C Owens

    Full Text Available The relative roles played by trafficking, fission and fusion in the dynamics of mitochondria in neurons have not been fully elucidated. In the present study, a slow widespread redistribution of mitochondria within cultured spinal cord motor neurons was observed as a result of extensive organelle fusion. Mitochondria were labeled with a photoconvertible fluorescent protein (mitoKaede that is red-shifted following brief irradiation with blue light. The behavior of these selectively labeled mitochondria was followed by live fluorescence imaging. Marking mitochondria within the cell soma revealed a complete mixing, within 18 hours, of these organelles with mitochondria coming from the surrounding neurites. Fusion of juxtaposed mitochondria was directly observed in neuritic processes at least 200 microns from the cell body. Within 24 hours, photoconverted mitoKaede was dispersed to all of the mitochondria in the portion of neurite under observation. When time lapse imaging over minutes was combined with long-term observation of marked mitochondria, moving organelles that traversed the field of view did not initially contain photoconverted protein, but after several hours organelles in motion contained both fluorescent proteins, coincident with widespread fusion of all of the mitochondria within the length of neurite under observation. These observations suggest that there is a widespread exchange of mitochondrial components throughout a neuron as a result of organelle fusion.

  6. Effects of doxorubicin on cardiac muscle subsarcolemmal and intermyofibrillar mitochondria

    Science.gov (United States)

    Kavazis, Andreas N.; Morton, Aaron B.; Hall, Stephanie E.; Smuder, Ashley J.

    2017-01-01

    Doxorubicin (DOX) is a highly effective chemotherapeutic used in the treatment of a broad spectrum of malignancies. However, clinical use of DOX is highly limited by cumulative and irreversible cardiomyopathy that occurs following DOX treatment. The pathogenesis of DOX-induced cardiac muscle dysfunction is complex. However, it has been proposed that the etiology of this myopathy is related to mitochondrial dysfunction, as a result of the dose-dependent increase in the mitochondrial accumulation of DOX. In this regard, cardiac muscle possesses two morphologically distinct populations of mitochondria. Subsarcolemmal (SS) mitochondria are localized just below the sarcolemma, whereas intermyofibrillar (IMF) mitochondria are found between myofibrils. Mitochondria in both regions exhibit subtle differences in biochemical properties, giving rise to differences in respiration, lipid composition, enzyme activities and protein synthesis rates. Based on the heterogeneity of SS and IMF mitochondria, we hypothesized that acute DOX administration would have distinct effects on each cardiac mitochondrial subfraction. Therefore, we isolated SS and IMF mitochondria from the hearts of female Sprague-Dawley rats 48 h after administration of DOX. Our results demonstrate that while SS mitochondria appear to accumulate greater amounts of DOX, IMF mitochondria demonstrate a greater apoptotic and autophagic response to DOX exposure. Thus, the divergent protein composition and function of the SS and IMF cardiac mitochondria result in differential responses to DOX, with IMF mitochondria appearing more susceptible to damage after DOX treatment. PMID:27832997

  7. Modeling RNA polymerase interaction in mitochondria of chordates

    Directory of Open Access Journals (Sweden)

    Lyubetsky Vassily A

    2012-08-01

    Full Text Available Abstract Background In previous work, we introduced a concept, a mathematical model and its computer realization that describe the interaction between bacterial and phage type RNA polymerases, protein factors, DNA and RNA secondary structures during transcription, including transcription initiation and termination. The model accurately reproduces changes of gene transcription level observed in polymerase sigma-subunit knockout and heat shock experiments in plant plastids. The corresponding computer program and a user guide are available at http://lab6.iitp.ru/en/rivals. Here we apply the model to the analysis of transcription and (partially translation processes in the mitochondria of frog, rat and human. Notably, mitochondria possess only phage-type polymerases. We consider the entire mitochondrial genome so that our model allows RNA polymerases to complete more than one circle on the DNA strand. Results Our model of RNA polymerase interaction during transcription initiation and elongation accurately reproduces experimental data obtained for plastids. Moreover, it also reproduces evidence on bulk RNA concentrations and RNA half-lives in the mitochondria of frog, human with or without the MELAS mutation, and rat with normal (euthyroid or hyposecretion of thyroid hormone (hypothyroid. The transcription characteristics predicted by the model include: (i the fraction of polymerases terminating at a protein-dependent terminator in both directions (the terminator polarization, (ii the binding intensities of the regulatory protein factor (mTERF with the termination site and, (iii the transcription initiation intensities (initiation frequencies of all promoters in all five conditions (frog, healthy human, human with MELAS syndrome, healthy rat, and hypothyroid rat with aberrant mtDNA methylation. Using the model, absolute levels of all gene transcription can be inferred from an arbitrary array of the three transcription characteristics, whereas, for

  8. A year (2014-2015) of plants in Proteomics journal. Progress in wet and dry methodologies, moving from protein catalogs, and the view of classic plant biochemists.

    Science.gov (United States)

    Sanchez-Lucas, Rosa; Mehta, Angela; Valledor, Luis; Cabello-Hurtado, Francisco; Romero-Rodrıguez, M Cristina; Simova-Stoilova, Lyudmila; Demir, Sekvan; Rodriguez-de-Francisco, Luis E; Maldonado-Alconada, Ana M; Jorrin-Prieto, Ana L; Jorrín-Novo, Jesus V

    2016-03-01

    The present review is an update of the previous one published in Proteomics 2015 Reviews special issue [Jorrin-Novo, J. V. et al., Proteomics 2015, 15, 1089-1112] covering the July 2014-2015 period. It has been written on the bases of the publications that appeared in Proteomics journal during that period and the most relevant ones that have been published in other high-impact journals. Methodological advances and the contribution of the field to the knowledge of plant biology processes and its translation to agroforestry and environmental sectors will be discussed. This review has been organized in four blocks, with a starting general introduction (literature survey) followed by sections focusing on the methodology (in vitro, in vivo, wet, and dry), proteomics integration with other approaches (systems biology and proteogenomics), biological information, and knowledge (cell communication, receptors, and signaling), ending with a brief mention of some other biological and translational topics to which proteomics has made some contribution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. MitoCeption as a new tool to assess the effects of mesenchymal stem/stromal cell mitochondria on cancer cell metabolism and function.

    Science.gov (United States)

    Caicedo, Andrés; Fritz, Vanessa; Brondello, Jean-Marc; Ayala, Mickaël; Dennemont, Indira; Abdellaoui, Naoill; de Fraipont, Florence; Moisan, Anaïck; Prouteau, Claire Angebault; Boukhaddaoui, Hassan; Jorgensen, Christian; Vignais, Marie-Luce

    2015-03-13

    Mitochondrial activity is central to tissue homeostasis. Mitochondria dysfunction constitutes a hallmark of many genetic diseases and plays a key role in tumor progression. The essential role of mitochondria, added to their recently documented capacity to transfer from cell to cell, obviously contributes to their current interest. However, determining the proper role of mitochondria in defined biological contexts was hampered by the lack of suitable experimental tools. We designed a protocol (MitoCeption) to directly and quantitatively transfer mitochondria, isolated from cell type A, to recipient cell type B. We validated and quantified the effective mitochondria transfer by imaging, fluorescence-activated cell sorting (FACS) and mitochondrial DNA analysis. We show that the transfer of minute amounts of mesenchymal stem/stromal cell (MSC) mitochondria to cancer cells, a process otherwise occurring naturally in coculture, results in cancer cell enhanced oxidative phosphorylation (OXPHOS) activity and favors cancer cell proliferation and invasion. The MitoCeption technique, which can be applied to different cell systems, will therefore be a method of choice to analyze the metabolic modifications induced by exogenous mitochondria in host cells.

  10. MitoCeption as a new tool to assess the effects of mesenchymal stem/stromal cell mitochondria on cancer cell metabolism and function

    Science.gov (United States)

    Caicedo, Andrés; Fritz, Vanessa; Brondello, Jean-Marc; Ayala, Mickaël; Dennemont, Indira; Abdellaoui, Naoill; de Fraipont, Florence; Moisan, Anaïck; Prouteau, Claire Angebault; Boukhaddaoui, Hassan; Jorgensen, Christian; Vignais, Marie-Luce

    2015-01-01

    Mitochondrial activity is central to tissue homeostasis. Mitochondria dysfunction constitutes a hallmark of many genetic diseases and plays a key role in tumor progression. The essential role of mitochondria, added to their recently documented capacity to transfer from cell to cell, obviously contributes to their current interest. However, determining the proper role of mitochondria in defined biological contexts was hampered by the lack of suitable experimental tools. We designed a protocol (MitoCeption) to directly and quantitatively transfer mitochondria, isolated from cell type A, to recipient cell type B. We validated and quantified the effective mitochondria transfer by imaging, fluorescence-activated cell sorting (FACS) and mitochondrial DNA analysis. We show that the transfer of minute amounts of mesenchymal stem/stromal cell (MSC) mitochondria to cancer cells, a process otherwise occurring naturally in coculture, results in cancer cell enhanced oxidative phosphorylation (OXPHOS) activity and favors cancer cell proliferation and invasion. The MitoCeption technique, which can be applied to different cell systems, will therefore be a method of choice to analyze the metabolic modifications induced by exogenous mitochondria in host cells. PMID:25766410

  11. Targeting microbiota-mitochondria inter-talk: Microbiota control mitochondria metabolism.

    Science.gov (United States)

    Saint-Georges-Chaumet, Y; Attaf, D; Pelletier, E; Edeas, M

    2015-09-26

    Our aim is to highlight the subtle relationship that exists between microbiota and mitochondria. Microbiota targets mitochondria by modulating the Reactive Oxygen Species (ROS) production and the mitochondrial activity through interactions with toxins, proteins or other metabolites released by gut microbiota. The intriguing relationship that exists between mitochondria and microbiota is strengthened by the probable prokaryotic origin of mitochondria. Emerging data implicates a role for ROS, nitric oxide, Short Chain Fatty Acids and hydrogen sulfide in the cross-talk between microbiota - mitochondria and REDOX signaling. Several studies have shown that microbiota act and modulate mitochondrial activity, and use it as a relay to strengthen host-microbiotal interaction. This modulation depends on the gut bacterial strain quality and diversity to increase its pathogenic versus beneficial effects. Furthermore, based on conclusions from new studies, it is possible that microbiota can directly interact with the host cell gene expression by favoring bacterial and mitochondrial DNA insertion in the nuclear genome. The emerging knowledge of mitochondria-microbiota interaction may be of great importance to better understand the mechanism of mitochondrial and metabolic diseases, and the syndromes associated with change in quality and quantity of microbiotal species. We suggest that microbiota via mitochondrial modulation influence cell homeostasis and metabolism. The challenge will be to find strategies to modulate the quality and diversity of microbiota rather than acting on microbiota metabolites and microbiota related factors. The medicine of tomorrow will be completely personalized. Firstly there will be a test to show the quality, quantity and diversity of microbiota, and secondly a preventive or therapeutic strategy will be administrated (probiotics, diet, prodrug or fecal transplantation). The era of digital medicine is here.

  12. Progression Produced Pharmaceutical Protein in Transgenic Plants%植物医药基因工程研究进程

    Institute of Scientific and Technical Information of China (English)

    王关林

    2001-01-01

    转基因植物是现代生产药用蛋白的一个廉价表达的系统,称为分子药田(molecular medicine farming)或医药工厂化农业(medicine factory farming).它已成为目前植物基因工程的研究热点。综述其研究进展及其独特的优势,提出进一步所要解决的问题,以利于该研究领域的深化。%Plant Genetic Engineering is a inexpensive productive system to generate pharmaceutical protein, its name is molecular medicine farming or medicine factory farming and the research view of pharmaceutical protein preduction. The paper reviews research progession and special advantage in the field and shows the questions settled futher for the development of research.

  13. Development of molten carbonate fuel cell power plant. Quarterly technical progress report, February 1-April 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J. R.

    1980-01-01

    Work has been initiated during this first quarter under all four program tasks and by all major participants as described. Task 1.0 activity (establish power plant reference design) concentrated upon definition of user requirements and establishment of power plant subsystem alternatives and characteristics. Task 2.0 work (stack and cell design development and verification) was initiated with a heavy emphasis upon test facilities preparation. A total of 27 laboratory cells were operated during this reporting period and a total of nine cells continued on test at the end of the quarter. Investigation of alternative anode and cathode materials proceeded; a dual-porosity anode was fabricated and tested. Over 10,000 endurance hours on a state-of-the-art cell carried-over from a previous program has been achieved and 1500 hours endurance has been obtained with sheet metal cells. Results presented for electrolyte structure development include comparative data for spray-dried and modified aqueous slurry process powders. Shake-down tests with a rotating disc electrode apparatus for fundamental measurements are described. Concept designs for both prototype and subscale stacks have been identified. Task 3.0 effort (development capability for full-scale stack tests) included preparation of an overall test plan to commercialization for molten carbonate fuel cells and of a functional specification for the tenth-scale stack test facility; drafts of both documents were completed for internal review. Cost-effective manufacturing assessment of available designs and processes was initiated. Task 4.0 work (develop capabilities for operation of stacks on coal-derived gas) included gathering of available contaminants concentration and effects information and preparation of initial projections of contaminant ranges and concentrations. Accomplishments to date and activities planned for the next quarter are described.

  14. Targeting cancer cell mitochondria as a therapeutic approach: recent updates.

    Science.gov (United States)

    Cui, Qingbin; Wen, Shijun; Huang, Peng

    2017-06-01

    Mitochondria play a key role in ATP generation, redox homeostasis and regulation of apoptosis. Due to the essential role of mitochondria in metabolism and cell survival, targeting mitochondria in cancer cells is considered as an attractive therapeutic strategy. However, metabolic flexibility in cancer cells may enable the upregulation of compensatory pathways, such as glycolysis to support cancer cell survival when mitochondrial metabolism is inhibited. Thus, compounds capable of both targeting mitochondria and inhibiting glycolysis may be particularly useful to overcome such drug-resistant mechanism. This review provides an update on recent development in the field of targeting mitochondria and novel compounds that impact mitochondria, glycolysis or both. Key challenges in this research area and potential solutions are also discussed.

  15. Transfer of mitochondria from astrocytes to neurons after stroke

    Science.gov (United States)

    Hayakawa, Kazuhide; Esposito, Elga; Wang, Xiaohua; Terasaki, Yasukazu; Liu, Yi; Xing, Changhong; Ji, Xunming; Lo, Eng H.

    2016-01-01

    Recently, it was suggested that neurons can release and transfer damaged mitochondria to astrocytes for disposal and recycling 1. This ability to exchange mitochondria may represent a potential mode of cell-cell signaling in the central nervous system (CNS). Here, we show that astrocytes can also release functional mitochondria that enter into neurons. Astrocytic release of extracellular mitochondria particles was mediated by a calcium-dependent mechanism involving CD38/cyclic ADP ribose signaling. Transient focal cerebral ischemia in mice induced astrocytic mitochondria entry to adjacent neurons that amplified cell survival signals. Suppression of CD38 signaling with siRNA reduced extracellular mitochondria transfer and worsened neurological outcomes. These findings suggest a new mitochondrial mechanism of neuroglial crosstalk that may contribute to endogenous neuroprotective and neurorecovery mechanisms after stroke. PMID:27466127

  16. Microtubule-Dependent Mitochondria Alignment Regulates Calcium Release in Response to Nanomechanical Stimulus in Heart Myocytes

    Directory of Open Access Journals (Sweden)

    Michele Miragoli

    2016-01-01

    Full Text Available Arrhythmogenesis during heart failure is a major clinical problem. Regional electrical gradients produce arrhythmias, and cellular ionic transmembrane gradients are its originators. We investigated whether the nanoscale mechanosensitive properties of cardiomyocytes from failing hearts have a bearing upon the initiation of abnormal electrical activity. Hydrojets through a nanopipette indent specific locations on the sarcolemma and initiate intracellular calcium release in both healthy and heart failure cardiomyocytes, as well as in human failing cardiomyocytes. In healthy cells, calcium is locally confined, whereas in failing cardiomyocytes, calcium propagates. Heart failure progressively stiffens the membrane and displaces sub-sarcolemmal mitochondria. Colchicine in healthy cells mimics the failing condition by stiffening the cells, disrupting microtubules, shifting mitochondria, and causing calcium release. Uncoupling the mitochondrial proton gradient abolished calcium initiation in both failing and colchicine-treated cells. We propose the disruption of microtubule-dependent mitochondrial mechanosensor microdomains as a mechanism for abnormal calcium release in failing heart.

  17. Respiratory properties and malate metabolism in Percoll-purified mitochondria isolated from pineapple, Ananas comosus (L.) Merr. cv. smooth cayenne.

    Science.gov (United States)

    Hong, Hoang Thi Kim; Nose, Akihiro; Agarie, Sakae

    2004-10-01

    An investigation was made of the respiratory properties and the role of the mitochondria isolated from one phosphoenolpyruvate carboxykinase (PCK)-CAM plant Ananas comosus (pineapple) in malate metabolism during CAM phase III. Pineapple mitochondria showed very high malate dehydrogenase (MDH), and low malic enzyme (ME) and glutamate-oxaloacetate transaminase (GOT) activities. The mitochondria readily oxidized succinate and NADH with high rates and coupling, while they only oxidized NADPH in the presence of Ca(2+). Pineapple mitochondria oxidized malate with low rates under most assay conditions, despite increasing malate concentrations, optimizing pH, providing cofactors such as coenzyme A, thiamine pyrophosphate, and NAD(+), and supplying individually external glutamate or GOT. However, providing glutamate and GOT simultaneously strongly increased the rates of malate oxidation. The OAA easily permeated the mitochondrial membranes to import into or export out of pineapple mitochondria during malate oxidation, but the mitochondria did not consume external Asp or alpha-KG. These results suggest that OAA played a significant role in the mitochondrial malate metabolism of pineapple, in which malate was mainly oxidized by active mMDH to produce OAA which could be exported outside the mitochondria via a malate-OAA shuttle. Cytosolic GOT then consumed OAA by transamination in the presence of glutamate, leading to a large increase in respiration rates. The malate-OAA shuttle might operate as a supporting system for decarboxylation in phase III of PCK-CAM pineapple. This shuttle system may be important in pineapple to provide a source of energy and substrate OAA for cytosolic PCK activity during the day when cytosolic OAA and ATP was limited for the overall decarboxylation process.

  18. Misfolded SOD1 associated with motor neuron mitochondria alters mitochondrial shape and distribution prior to clinical onset.

    Directory of Open Access Journals (Sweden)

    Christine Vande Velde

    Full Text Available Mutations in superoxide dismutase (SOD1 are causative for inherited amyotrophic lateral sclerosis. A proportion of SOD1 mutant protein is misfolded onto the cytoplasmic face of mitochondria in one or more spinal cord cell types. By construction of mice in which mitochondrially targeted enhanced green fluorescent protein is selectively expressed in motor neurons, we demonstrate that axonal mitochondria of motor neurons are primary in vivo targets for misfolded SOD1. Mutant SOD1 alters axonal mitochondrial morphology and distribution, with dismutase active SOD1 causing mitochondrial clustering at the proximal side of Schmidt-Lanterman incisures within motor axons and dismutase inactive SOD1 producing aberrantly elongated axonal mitochondria beginning pre-symptomatically and increasing in severity as disease progresses. Somal mitochondria are altered by mutant SOD1, with loss of the characteristic cylindrical, networked morphology and its replacement by a less elongated, more spherical shape. These data indicate that mutant SOD1 binding to mitochondria disrupts normal mitochondrial distribution and size homeostasis as early pathogenic features of SOD1 mutant-mediated ALS.

  19. 植物多糖干预细胞黏附研究进展%Research progresses of plant polysaccharides on cell adhesion

    Institute of Scientific and Technical Information of China (English)

    徐先祥; 刁勇; 许瑞安; 孙爱静

    2012-01-01

    黏附分子介导的细胞黏附是最基本的生命现象,也是炎症、免疫、感染、血栓形成、肿瘤转移、伤口愈合等生理病理过程的细胞学基础,干预黏附己成为疾病防治的重要策略.植物多糖特别是中草药中的多糖具有抗炎、抗肿瘤、抗感染、调节免疫、保护心血管等多样的药理作用,本文综述了植物多糖对疾病过程中细胞黏附的干预作用.%Cell adhesion mediated by cell adhesion molecules (CAMs) constitutes essential life phenomenon. In inflammation, immunity, infection, thrombosis, tumor metastasis and wound healing, cell adhesion comes into being the basic physiological and pathological process. Intervening with cell adhesion has been the important therapeutic and prophylactic strategies for diseases. Accumulated evidence has indicated that plant polysaccharides especially those exacted from Chinese traditional and herbal drugs displayed various pharmacological effects such as anti-inflammation, anti-cancer, anti-infection, immunomodulation, cardiovascular protective effects and so on. In this paper, the research progress of plant polysaccharides on cell adhesion is reviewed.

  20. Progress in Research onSTAY-GREEN Genes in Plants%植物滞绿基因STAY-GREEN的研究进展

    Institute of Scientific and Technical Information of China (English)

    孙佩光; 吴琼; 徐碧玉; 常胜合; 苗红霞; 金志强

    2015-01-01

    滞绿基因STAY-GREEN (SGR)是绿色器官衰老/成熟的关键调控因子,通过系统进化分析将其分为SGR和SGR-LIKE (SGRL)两大亚家族。在不同物种中SGR和SGRL基因的序列特征、表达模式及功能均存在一定差异,且同源基因之间的功能也不尽一致。本文概述了近年来国内外SGR/SGRL基因的最新研究进展,主要包括SGR/SGRL基因的染色体定位、分类和表达模式及可能具有的功能等。%STAY-GREEN (SGR) genes are key regulatory factors involved in senescence and ripening process in plant green organs. Based on phylogenetic analysis,STAY-GREEN genes were divided into two groups,SGR andSGR-LIKE (SGRL) subfamilies. However, there are some differences betweenSGR andSGRL in sequence features, expression patterns and functional characters among different plant species, while the functions for SGR/SGRL homolog genes are not the same. In this article, we summarize the research progress inSGR/SGRL genes in recent years including the chromosome location, classiifcation and expression, and possible functions ofSGR/SGRL genes.

  1. 气体信号分子H2S在植物中的研究进展%Research Progress in the Gasotransmitter Hydrogen Sulifde in Plants

    Institute of Scientific and Technical Information of China (English)

    李顺; 景举伟; 严金平; 陈宣钦; 徐慧妮

    2015-01-01

    硫化氢(hydrogen sulifde, H2S)是继一氧化氮(nitric oxide, NO)和一氧化碳(carbon monoxide, CO)之后的第三个气体信号分子。近年来,人们对动物中H2S的内源性生成、生物学效应及其分子机制等方面进行了广泛研究,但H2S在植物中的研究相对较少。本文综述了植物体内H2S的性质及存在方式、产生途径、在植物生长发育及非生物胁迫下的作用、与其他信号分子的互作等的最新研究进展。%Hydrogen sulifde (H2S) is considered as the third new member of gasotransmitter family, following nitric oxide (NO) and carbon monoxide (CO). Recently, many researches have been done about the production, biological effect, and molecular mechanisms of H2S in animals, but the researches of H2S in plants are relatively few. This paper summarized the new research progress in the characteristics, production pathway, functions in plant growth and development and under abiotic stresses, as well as the cross talk with the other signaling molecules of endogenous H2S.

  2. Structure of cristae in cardiac mitochondria of aged rat

    OpenAIRE

    Riva, Alessandro; Tandler, Bernard; Lesnefsky, Edward J.; Conti, Gabriele; Loffredo, Felice; Vazquez, Edwin; Charles L Hoppel

    2006-01-01

    Interfibrillar mitochondria (IFM) of the heart in aged Fischer 344 rats show a biochemical defect which might be reflected in their morphology. We examined by high resolution scanning electron microscopy over 5,500 mitochondria to determine if a concomitant structural alteration existed. This methodology provides a means of examining mitochondrial cristae in three dimensions. Cristae of in situ subsarcolemmal mitochondria (SSM) and of IFM in both 6 and 24 month old Fischer rats are predominan...

  3. Intracoronary Delivery of Mitochondria to the Ischemic Heart for Cardioprotection.

    Science.gov (United States)

    Cowan, Douglas B; Yao, Rouan; Akurathi, Vamsidhar; Snay, Erin R; Thedsanamoorthy, Jerusha K; Zurakowski, David; Ericsson, Maria; Friehs, Ingeborg; Wu, Yaotang; Levitsky, Sidney; Del Nido, Pedro J; Packard, Alan B; McCully, James D

    2016-01-01

    We have previously shown that transplantation of autologously derived, respiration-competent mitochondria by direct injection into the heart following transient ischemia and reperfusion enhances cell viability and contractile function. To increase the therapeutic potential of this approach, we investigated whether exogenous mitochondria can be effectively delivered through the coronary vasculature to protect the ischemic myocardium and studied the fate of these transplanted organelles in the heart. Langendorff-perfused rabbit hearts were subjected to 30 minutes of ischemia and then reperfused for 10 minutes. Mitochondria were labeled with 18F-rhodamine 6G and iron oxide nanoparticles. The labeled mitochondria were either directly injected into the ischemic region or delivered by vascular perfusion through the coronary arteries at the onset of reperfusion. These hearts were used for positron emission tomography, microcomputed tomography, and magnetic resonance imaging with subsequent microscopic analyses of tissue sections to confirm the uptake and distribution of exogenous mitochondria. Injected mitochondria were localized near the site of delivery; while, vascular perfusion of mitochondria resulted in rapid and extensive dispersal throughout the heart. Both injected and perfused mitochondria were observed in interstitial spaces and were associated with blood vessels and cardiomyocytes. To determine the efficacy of vascular perfusion of mitochondria, an additional group of rabbit hearts were subjected to 30 minutes of regional ischemia and reperfused for 120 minutes. Immediately following regional ischemia, the hearts received unlabeled, autologous mitochondria delivered through the coronary arteries. Autologous mitochondria perfused through the coronary vasculature significantly decreased infarct size and significantly enhanced post-ischemic myocardial function. In conclusion, the delivery of mitochondria through the coronary arteries resulted in their rapid

  4. 植物着丝粒结构及进化的研究进展%Research Progress on Structure and Evolution of Plant Centromeres

    Institute of Scientific and Technical Information of China (English)

    刘青

    2015-01-01

    植物着丝粒是染色体重要结构域,介导动粒装配。不同物种间着丝粒重复序列快速趋异进化,着丝粒功能保守,确保有丝分裂和减数分裂过程中染色体正确分离和准确传递。伴随染色质免疫共沉淀技术(Chromatin immunoprecipitation, ChIP)、ChIP与高密度芯片相结合技术(ChIP-chip)、ChIP与高通量测序相结合技术(ChIP-seq)的应用,植物着丝粒研究获得里程碑式进展:某些模式植物着丝粒DNA序列、蛋白质结构、功能获得大量新认识;着丝粒基本蛋白质组蛋白H3被用来界定着丝粒大小和边界;某些非着丝粒区域被激活为新着丝粒,在世代传递中保持稳定性。本文对植物着丝粒结构、功能、进化研究进行了综述,并探讨了植物着丝粒研究存在的问题。%The plant centromere is the most important chromosome domain mediating the assembly of kinetochore. The rapid divergent evolution of centromeric repeat sequences and function conservation of centromeres among different species ensure correct segregation and faithful transmission of chromosome in mitosis and meiosis. Along with the development of chromatin immunoprecipitation (ChIP), ChIP-chip, and ChIP-sequencing (ChIP-seq) technologies, three milestone discoveries have achieved in plant centromere research since the last 20 years, such as a lot of new knowledge on the structure, function, and evolution of centromeres from model plants, the fundamental kinetochore protein CENH3 used to delimiting the size and boundaries of centromere, the neocentromeres activated from non-centromeric regions stably transmitted to subsequent generations. The research progress on structure, function, and evolution of plant centromeres are reviewed and the remaining questions of plant centromere studies are discussed.

  5. 天然植物精油提取方法研究进展%Research Progress of Natural Plant Essential Oil Extraction Methods

    Institute of Scientific and Technical Information of China (English)

    杨君; 张献忠; 高宏建; 尹洁; 叶兴乾

    2012-01-01

    Plant essential oils are formed by secondary metabolites of aromatic plants.They are valuable natural products and are used as raw materials in many fields,including spices,cosmetics,industries,pharmaceutical and agriculture as they have many biological activities.There are several methods for extracting essential oils.This paper introduced the extraction methods of plant essential oil and the principles.Meanwhile,advantages and disadvantages,application scope,and research progress of these methods were summarized.%植物精油是一类天然植物次生代谢物,由于其具有增香、杀菌、抗病毒和抗氧化等生物活性,在香料、化妆品、食品工业、制药、医疗及农业害虫等方面得到了广泛应用。植物精油的提取方法多种多样,且不同用途的精油产品需要用不同的提取方法来生产。就植物精油传统提取方法及新兴提取方法进行综述,并且总结了这些方法的原理、优缺点以及适用范围,对未来植物精油提取方法的发展进行展望。

  6. Research progress of plant receptor like kinase CR4%植物受体样激酶CR4家族

    Institute of Scientific and Technical Information of China (English)

    姚清国; 肖颖; 魏青; 崔文广; 于宏伟

    2011-01-01

    Receptor like kinases play important roles in the development of plants.CRINKLY4 (CR4) is a growth factor-like plant receptor kinase including ZmCR4 in Zea mays, ACR4 in Arabidopsis and OsCR4 in rice.They exert a great influence on a wide array of developmental processes including plant cell proliferation and differentiation, cell fate and pattern.ZmCR4 affects the pattern leaf epidermis and in the aleurone of the endosperm.ACR4 promots formative cell divisions in the pericycle and controls in the number of the division cells when organogenesis has been started.This paper summarized the research progress of CR4 family.%受体样激酶在植物的生长发肯中发挥着重要的功能.CRINKLY4(简称CR4)属于生长因子类的受体激酶,包括玉米中的ZmCR4、拟南芥中的ACR4和水稻中的OsCR4,参与了植物细胞的增殖和分化,包括细胞分化命运和发育方向.ZmCR4影响了玉米表皮细胞的形态和糊粉层的发育,ACR4启动拟南芥根中形成层细胞的分化,而且器官发生开始后可以控制细胞分化的数目.本文对植物受体样激酶CR4家族近年的研究进展进行了总结.

  7. Inner membrane fusion mediates spatial distribution of axonal mitochondria

    Science.gov (United States)

    Yu, Yiyi; Lee, Hao-Chih; Chen, Kuan-Chieh; Suhan, Joseph; Qiu, Minhua; Ba, Qinle; Yang, Ge

    2016-01-01

    In eukaryotic cells, mitochondria form a dynamic interconnected network to respond to changing needs at different subcellular locations. A fundamental yet unanswered question regarding this network is whether, and if so how, local fusion and fission of individual mitochondria affect their global distribution. To address this question, we developed high-resolution computational image analysis techniques to examine the relations between mitochondrial fusion/fission and spatial distribution within the axon of Drosophila larval neurons. We found that stationary and moving mitochondria underwent fusion and fission regularly but followed different spatial distribution patterns and exhibited different morphology. Disruption of inner membrane fusion by knockdown of dOpa1, Drosophila Optic Atrophy 1, not only increased the spatial density of stationary and moving mitochondria but also changed their spatial distributions and morphology differentially. Knockdown of dOpa1 also impaired axonal transport of mitochondria. But the changed spatial distributions of mitochondria resulted primarily from disruption of inner membrane fusion because knockdown of Milton, a mitochondrial kinesin-1 adapter, caused similar transport velocity impairment but different spatial distributions. Together, our data reveals that stationary mitochondria within the axon interconnect with moving mitochondria through fusion and fission and that local inner membrane fusion between individual mitochondria mediates their global distribution. PMID:26742817

  8. A BID on mitochondria with MTCH2

    Institute of Scientific and Technical Information of China (English)

    Sara Cogliati; Luca Scorrano

    2010-01-01

    @@ Apoptosis is a key process for tissue homeostasis and renewal. Its dysregulation is implicated in most human diseases, from cancer to neurodegeneration. Apoptosis is triggered by stimuli that damage the internal structures of the cell, or by specialized "death"receptors on its surface. In certain cell types, Bid, a "BH3-only" member of the Bcl-2 family of death regulators integrates these two pathways at the mitochondrial level. Despite years of intense research, the mechanisms by which Bid translocates to mitochondria remain unclear. A recent study by Gross and colleagues sheds new light on this process.

  9. BioMEMS for mitochondria medicine

    Science.gov (United States)

    Padmaraj, Divya

    A BioMEMS device to study cell-mitochondrial physiological functionalities was developed. The pathogenesis of many diseases including obesity, diabetes and heart failure as well as aging has been linked to functional defects of mitochondria. The synthesis of Adenosine Tri Phosphate (ATP) is determined by the electrical potential across the inner mitochondrial membrane and by the pH difference due to proton flux across it. Therefore, electrical characterization by E-fields with complementary chemical testing was used here. The BioMEMS device was fabricated as an SU-8 based microfluidic system with gold electrodes on SiO2/Si wafers for electromagnetic interrogation. Ion Sensitive Field Effect Transistors (ISFETs) were incorporated for proton studies important in the electron transport chain, together with monitoring Na+, K+ and Ca++ ions for ion channel studies. ISFETs are chemically sensitive Metal Oxide Semiconductor Field Effect Transistor (MOSFET) devices and their threshold voltage is directly proportional to the electrolytic H+ ion variation. These ISFETs (sensitivity ˜55 mV/pH for H+) were further realized as specific ion sensitive Chemical Field Effect Transistors (CHEMFETs) by depositing a specific ion sensitive membrane on the gate. Electrodes for dielectric spectroscopy studies of mitochondria were designed as 2- and 4-probe structures for optimized operation over a wide frequency range. In addition, to limit polarization effects, a 4-electrode set-up with unique meshed pickup electrodes (7.5x7.5 mum2 loops with 4 mum wires) was fabricated. Sensitivity of impedance spectroscopy to membrane potential changes was confirmed by studying the influence of uncouplers and glucose on mitochondria. An electrical model was developed for the mitochondrial sample, and its frequency response correlated with impedance spectroscopy experiments of sarcolemmal mitochondria. Using the mesh electrode structure, we obtained a reduction of 83.28% in impedance at 200 Hz. COMSOL

  10. Isolation of mitochondria from animal tissue.

    Science.gov (United States)

    Clayton, David A; Shadel, Gerald S

    2014-10-01

    Rat or mouse liver is the most frequently used tissue for mitochondrial preparations because it is readily available, easy to homogenize, and replete with mitochondria. A motor-driven Teflon and glass Potter-Elvehjem homogenizer is the best choice for homogenizing liver, but if one is not available, this tissue is soft enough that a Dounce homogenizer with a loose (A) pestle can also be used. The yield and purity of the mitochondrial preparation will be influenced by the method and speed of preparation and the age and physiological condition of the animal. © 2014 Cold Spring Harbor Laboratory Press.

  11. Isozymes of Superoxide Dismutase in Mitochondria and Peroxisomes Isolated from Petals of Carnation (Dianthus caryophyllus) during Senescence.

    Science.gov (United States)

    Droillard, M J; Paulin, A

    1990-11-01

    The balance between reactions involving free radicals and processes which ameliorate their effect plays an important role in the regulation of plant senescence. In this study a method was developed to isolate peroxisomes and mitochondria from carnation (Dianthus caryophyllus L. cv Ember) petals. Based on electron microscopy and marker enzyme levels, the proportion of peroxisomes to mitochondria increases during senescence. The superoxide dismutase (SOD) content of these fractions was examined. Mitochondria and peroxisomes were shown to contain two electrophoretically distinct SODs, a manganese-, and an ironcontaining SOD. The Mn- and Fe-SOD were found to have relative molecular weights of 75,000 and 48,000 and isoelectric points of 4.85 and 5.00, respectively. The presence of a Fe-SOD in mitochondria and peroxisomes is unique because this enzyme is usually located in chloroplasts. The activity of these two isoenzymes decreased during senescence in mitochondria but remained high in peroxisomes from senescent tissue. It is suggested that peroxisomes play a particular role in the process of senescence.

  12. The progressive and ancestral traits of the secondary xylem within Magnolia clad – the early diverging lineage of flowering plants

    Directory of Open Access Journals (Sweden)

    Magdalena Marta Wróblewska

    2015-01-01

    Full Text Available The qualitative and quantitative studies, presented in this article, on wood anatomy of various species belonging to ancient Magnolia genus reveal new aspects of phylogenetic relationships between the species and show evolutionary trends, known to increase fitness of conductive tissues in angiosperms. They also provide new examples of phenotypic plasticity in plants. The type of perforation plate in vessel members is one of the most relevant features for taxonomic studies. In Magnolia, until now, two types of perforation plates have been reported: the conservative, scalariform and the specialized, simple one. In this paper, are presented some findings, new to magnolia wood science, like exclusively simple perforation plates in some species or mixed perforation plates – simple and scalariform in one vessel member. Intravascular pitting is another taxonomically important trait of vascular tissue. Interesting transient states between different patterns of pitting in one cell only have been found. This proves great flexibility of mechanisms, which elaborate cell wall structure in maturing tracheary element. The comparison of this data with phylogenetic trees, based on the fossil records and plastid gene expression, clearly shows that there is a link between the type of perforation plate and the degree of evolutionary specialization within Magnolia genus.

  13. Construction of a bacterial artificial chromosome library of S-type CMS maize mitochondria

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to isolate mitochondrial genes easily, we have developed a new method to construct S-type CMS maize mitochondrial gene library by means of embedding mitochondria and enzymatic digesting mitochondria in situ, preparing mtDNA by electrophoresis, digesting LMP agarose with β-agarase, using BAC vector and electroporation. About 2 500 white clones of Mo17 CMS-J mitochondrial gene library were obtained with the average size of 18.24 kb, ranging from 5 to 40 kb, 63.6% inserts came from mitochondrial genome and represented 48 ′ mitochondrial genome equivalents. All the probes had detected the positive clones in the gene library. It is helpful to elucidating the maize mitochondrial genome structure and mechanism of S-type CMS, and may give some valuable reference to the construction of other plant mitochondrial genome library.

  14. Distribution of the Respiratory Pathways in the Isolated Mitochondria from Etiolated Leaves of Winter Wheat and Rye after the Action of Low Temperature

    Directory of Open Access Journals (Sweden)

    Olga A. Borovik

    2016-11-01

    Full Text Available The effect of low temperature (2 °С, 7 days on the content of soluble carbohydrates in the leaves and oxidative activity of isolated mitochondria from the etiolated plants of winter wheat (Triticum aestivum L. and winter rye (Secale cereale L. has been studied. This paper describes the effect of low temperature on the distribution of the respiratory pathways in the isolated mitochondria from etiolated leaves of winter wheat and rye that are different by resistance to cold. With using the different oxidation substrates (malate, malate + rotenone, succinate, NADH and NADPH, we identified changes in the oxidative activity of winter wheat and rye mitochondria. In this work, the dependence of the functioning of cyanide-insensitive oxidase and rotenone-insensitive NAD(PH dehydrogenases in the isolated mitochondria of winter cereals from content of the soluble carbohydrates is discussed.

  15. The Influence of Carbohydrate Status and Low Temperature on the Respiratory Metabolism of Mitochondria from Etiolated Leaves of Winter Wheat

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    Olga A. Borovik

    2014-12-01

    Full Text Available The separate and combined effect of sucrose (12%, 7 days and low temperature (2 °С, 7 days on the growth of plants, the content of carbohydrates in the leaves and oxidative activity of mitochondria isolated from them has been studied on the etiolated plants of winter wheat (Triticum aestivum L.. It has been shown that sucrose and low temperature cause inhibition of the growth and increasing of the carbohydrates content. Using the different oxidation substrates (malate, malate + rotenone, succinate, NADH and NADPH have been identified changes in the mitochondrial oxidative activity and the functioning of alternative oxidase and rotenone-insensitive NAD(PH dehydrogenases. It has been determined that activity of the alternative oxidase and “external” rotenone-insensitive NAD(PH dehydrogenases in the mitochondria of etiolated leaves depends on the carbohydrate status of the plant, regardless of the growth temperature.

  16. 植物DNA条形码技术的发展及应用%Progress and application of DNA barcoding technique in plants

    Institute of Scientific and Technical Information of China (English)

    刘宇婧; 刘越; 黄耀江; 龙春林

    2011-01-01

    Based on summarization and analysis of development process of DNA barcoding technique,research progress of DNA barcoding technique in plants, its working process and analysis method,influencing factors on its identification accuracy, its application status and dispute existing in plant taxonomic study were comprehensively analyzed and described, and further development trend and application prospect of DNA barcoding technique in plants were proposed. By means of some research examples, it was indicated that combining method of DNA barcoding technique in plants and traditional botanical knowledge could be taken as one of studying ways for ethnobotany. And also, it was suggested that common DNA barcoding in plants mainly were two modes of single fragment and multiple fragments combining, and both of them had their respective advantages and disadvantages. Common DNA sequences included matK, trnH-psbA, rbcL and ITS, etc, but they all had a certain limitation. Different standards of DNA barcoding in plants should be selected in order to different application aims.Influencing factors on its identification accuracy included type and number of species, construction method of phylogenetic tree, hybridization and gene introgression, variance of species origin time and variance of molecular evolution rate. Current focus on DNA barcoding in plants is how to select suitable DNA fragments and to evaluate their values.%在对DNA条形码技术的发展过程进行归纳分析的基础上,对植物DNA条形码技术的研究进展、工作流程及分析方法、影响其鉴定准确性的因素及其在植物分类学研究中的应用现状及存在的争议进行了综合分析和阐述,并展望了植物DNA条形码技术的发展趋势及应用前景.通过具体实例说明将植物DNA条形码技术与传统植物学知识相结合可作为民族植物学的研究手段之一.认为:目前常用的植物DNA条形码主要有单一片段和多片段组合2种方式,这2种

  17. Mitochondria: Target organelles for estrogen action

    Directory of Open Access Journals (Sweden)

    Małgorzata Chmielewska

    2017-06-01

    Full Text Available Estrogens belong to a group of sex hormones, which have been shown to act in multidirectional way. Estrogenic effects are mediated by two types of intracellular receptors: estrogen receptor 1 (ESR1 and estrogen receptor 2 (ESR2. There are two basic mechanisms of estrogen action: 1 classical-genomic, in which the ligand-receptor complex acts as a transcriptional factor and 2 a nongenomic one, which is still not fully understood, but has been seen to lead to distinct biological effects, depending on tissue and ligand type. It is postulated that nongenomic effects may be associated with membrane signaling and the presence of classical nuclear receptors within the cell membrane. Estrogens act in a multidirectional way also within cell organelles. It is assumed that there is a mechanism which manages the migration of ESR into the mitochondrial membrane, wherein the exogenous estrogen affect the morphology of mitochondria. Estrogen, through its receptor, can directly modulate mitochondrial gene expression. Moreover, by regulating the level of reactive oxygen species, estrogens affect the biology of mitochondria. The considerations presented in this paper indicate the pleiotropic effects of estrogens, which represent a multidirectional pathway of signal transduction.

  18. Vesicular transport of a ribonucleoprotein to mitochondria

    Directory of Open Access Journals (Sweden)

    Joyita Mukherjee

    2014-10-01

    Full Text Available Intracellular trafficking of viruses and proteins commonly occurs via the early endosome in a process involving Rab5. The RNA Import Complex (RIC-RNA complex is taken up by mammalian cells and targeted to mitochondria. Through RNA interference, it was shown that mito-targeting of the ribonucleoprotein (RNP was dependent on caveolin 1 (Cav1, dynamin 2, Filamin A and NSF. Although a minor fraction of the RNP was transported to endosomes in a Rab5-dependent manner, mito-targeting was independent of Rab5 or other endosomal proteins, suggesting that endosomal uptake and mito-targeting occur independently. Sequential immunoprecipitation of the cytosolic vesicles showed the sorting of the RNP away from Cav1 in a process that was independent of the endosomal effector EEA1 but sensitive to nocodazole. However, the RNP was in two types of vesicle with or without Cav1, with membrane-bound, asymmetrically orientated RIC and entrapped RNA, but no endosomal components, suggesting vesicular sorting rather than escape of free RNP from endosomes. In vitro, RNP was directly transferred from the Type 2 vesicles to mitochondria. Live-cell imaging captured spherical Cav1− RNP vesicles emerging from the fission of large Cav+ particles. Thus, RNP appears to traffic by a different route than the classical Rab5-dependent pathway of viral transport.

  19. Mitochondria-targeting for improved photodynamic therapy

    Science.gov (United States)

    Ngen, Ethel J.

    Photodynamic therapy (PDT) is an emerging cancer therapeutic modality, with great potential to selectively treat surface cancers, thus minimizing systemic side effects. In this dissertation, two approaches to deliver photosensitizers to mitochondria were investigated: 1) Reducing photosensitizer sizes to improve endocytosis and lysosomal localization. Upon irradiation the photosensitizers would then produce singlet oxygen which could rupture the lysosomal membrane releasing the lysosomally trapped photosensitizers to the cytosol, from where they could relocalize to mitochondria by passive diffusion (photochemical internalization). 2) Using delocalized lipophilic cationic dyes (DLCs) to exploit membrane potential differences between the cytoplasm and mitochondria in delivering photosensitizers to mitochondria. To investigate the effects of steric hindrance on mitochondrial localization and photodynamic response, a series of eight thiaporphyrins were studied. Two new thiaporphyrin analogues 6 and 8 with reduced steric hindrance at the 10- and 15- meso positions were studied in comparison to 5,20-diphenyl-10,15-bis[4 (carboxymethyleneoxy)-phenyl]-21,23-dithiaporphyrin 1, previously validated as a potential second generation photosensitizer. Although 6 showed an extraordinarily high uptake (7.6 times higher than 1), it was less potent than 1 (IC 50 = 0.18 muM versus 0.13 muM) even though they both showed similar sub-cellular localization patterns. This low potency was attributed to its high aggregation tendency in aqueous media (4 times higher than 1), which might have affected its ability to generate singlet oxygen in vitro . 8 on the other hand showed an even lower potency than 6 (2.28 vs 0.18 muM). However this was attributed to its low cellular uptake (20 times less than 6) and inefficient generation of singlet oxygen. Overall, although the structural modifications did improve the cellular uptake of 6, 6 was still less potent than the lead photosensitizers 1. Thus

  20. MITOCHONDRIA QUALITY CONTROL AND MUSCLE MASS MAINTENANCE

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    Vanina eRomanello

    2016-01-01

    Full Text Available Loss of muscle mass and force occurs in many diseases such as disuse/inactivity, diabetes, cancer, renal and cardiac failure and in aging-sarcopenia. In these catabolic conditions the mitochondrial content, morphology and function are greatly affected. The changes of mitochondrial network influence the production of reactive oxygen species (ROS that play an important role in muscle function. Moreover, dysfunctional mitochondria trigger catabolic signaling pathways which feed-forward to the nucleus to promote the activation of muscle atrophy. Exercise, on the other hand, improves mitochondrial function by activating mitochondrial biogenesis and mitophagy, possibly playing an important part in the beneficial effects of physical activity in several diseases. Optimised mitochondrial function is strictly maintained by the coordinated activation of different mitochondrial quality control pathways. In this review we outline the current knowledge linking mitochondria-dependent signaling pathways to muscle homeostasis in aging and disease and the resulting implications for the development of novel therapeutic approaches to prevent muscle loss.

  1. 室内植物对甲醛净化性能的研究进展%Progress of Research on the Purification of Formaldehyde by Plants

    Institute of Scientific and Technical Information of China (English)

    蔡宝珍; 金荷仙; 熊伟

    2011-01-01

    随着人们生活水平的提高,室内空气净化已成为人们普遍关心的问题,而甲醛作为室内空气污染的头号杀手,引起了人们的巨大关注.笔者简述室内甲醛污染的来源、危害以及净化甲醛的重要性.与物理吸附、化学吸收、光催化和生物降解等技术相比,植物净化甲醛技术具有自然、环保、操作简单的特点,已经成为室内甲醛净化和室内植物景观研究的热点和前沿科学之一.综述植物净化甲醛的国内外研究进展,着重从吸附净化、代谢净化及根际微生物的降解净化等3方面阐述植物净化甲醛的机理,介绍植物净化甲醛的毒理研究进展,同时指出目前研究中存在的主要问题,并进一步提出未来的研究发展方向.%Purification of indoor polluted air becomes a common concern topic along with living standards'enhancement.As the top killer of indoor polluted air, the formaldehyde pollution was of special concern.The origin of formaldehyde and its enormous pollution in indoor air were inevitable, so it was very import to purify indoor air formaldehyde.Compared with technology of physical absorption, chemical absorption, photocatalytic biodegradable, the purification of formaldehyde by plant was natural, environmental and easy operate, which became the hot topic and advanced science in the research of purification of indoor formaldehyde and houseplant landscape.The domestic and abroad research progress of aerobic granular sludge was summerized.The theory of purification of formaldehyde was the absorption by the stem and foliage, the metabolism and transformation by the plant, and the degradation by the rhizosphere microorganism.Toxicological purification of formaldehyde by indoor plants was viewed.Advantages and disadvantages in research were reported, too.Finally, the foreground of the purification of formaldehyde by indoor plants was prospected.

  2. Research Progress on Plant Physiological Processes in Response to Climate Change%植物对气候变化生理响应研究进展

    Institute of Scientific and Technical Information of China (English)

    冯彩云; 许新桥; 马月萍; 孙振元; 冯世强

    2012-01-01

    Since the industrial revolution, human activities, especially in the developed countries, have consumed a great amount of resources and energy in the process of industrialization, which have resulted in the increased concentration of greenhouse gases in the air and triggered the global climate change. The change has not only brought severe challenges to human survival and development, but also imposed impacts on the physiological processes of plants. The influences on plant physiological processes by enriching CO2, changing climate factors and environmental stress factors have attracted wide concerns of scientists. This paper attempted to classify and analyze the national and international research on the influence of climate change on plant physiological processes carried out in recent years, and described the research progress of plant physiological response to CO2, temperature and moisture. Finally, the future research directions were prospected.%自工业革命以来,人类活动尤其是发达国家在工业化过程中消耗大量资源、能源,造成大气中温室气体浓度增加,引起全球范围内的气候变化,给人类的生存和发展带来严峻挑战,也对植物的生理过程产生了影响。关于CO2浓度升高及其与气候因子和环境胁迫因子对植物生理过程的影响已引起各国科学家广泛关注。文中就近年来气候变化对植物生理过程的影响国内外研究进行归类和分析,介绍了植物对CO2、温度、水分等因素变化的响应过程研究进展,并提出对进一步研究的展望。

  3. Progresso da ferrugem do cafeeiro irrigado em diferentes densidades de plantio pós-poda Progress of rust in coffee plants in various densities of cultivation in irrigated planting after pruning

    Directory of Open Access Journals (Sweden)

    Bernardo Reis Teixeira Lacerda Paiva

    2011-02-01

    Full Text Available Objetivou-se, no presente trabalho, avaliar o efeito de diferentes critérios para manejo da irrigação em quatro densidades de plantio, sob sistema de gotejamento na incidência e severidade da ferrugem do cafeeiro e avaliar a influência do enfolhamento na curva de progresso dessa doença. Conduziu-se, o experimento, em área experimental da Universidade Federal de Lavras MG, utilizando a cultivar Rubi MG-1192 com seis anos. O delineamento experimental foi em blocos ao acaso com quatro repetições. Os tratamentos foram constituídos por quatro parcelas representadas pelas densidades de plantio (convencionais e adensados: 2500 (4,0x1,0 m, 3333 (3,0x1,0 m, 5000 (2,0x1,0 m, 10000 (2,0x0,5 m plantas ha-1, quatro subparcelas sendo: irrigações quando a tensão da água no solo atingiu valores de 20 e 60kPa; irrigações utilizando o manejo do balanço hídrico (calculado através do software IRRIPLUS, com turnos de irrigação fixos de três dias por semana e uma testemunha sem irrigação, perfazendo um total de 16 tratamentos. Cada subparcela foi constituída por 10 plantas, sendo consideradas como plantas úteis as seis centrais. Foram avaliadas a incidência e severidade da ferrugem e a porcentagem de enfolhamento das plantas de cafeeiros. Após análise estatística, os dados foram convertidos em área abaixo da curva de progresso da doença e do crescimento. Verificou-se que os critérios para manejo da irrigação influenciaram a curva de progresso do crescimento, porém, não interferiu na curva de progresso da incidência e da severidade da ferrugem. Os sistemas de plantios adensados favoreceram a incidência da ferrugem. Mas as densidades de plantio não interferiram no enfolhamento.The objective of this study was to evaluate the effect of different irrigation controls implemented in four planting densities on a system of drip on the incidence and severity of rust and to assess the influence of leaf growth on the progress curve of this

  4. Subcellular immunocytochemical analysis detects the highest concentrations of glutathione in mitochondria and not in plastids.

    Science.gov (United States)

    Zechmann, B; Mauch, F; Sticher, L; Müller, M

    2008-01-01

    The tripeptide glutathione is a major antioxidant and redox buffer with multiple roles in plant metabolism. Glutathione biosynthesis is restricted to the cytosol and the plastids and the product is distributed to the various organelles by unknown mechanisms. In the present study immunogold cytochemistry based on anti-glutathione antisera and transmission electron microscopy was used to determine the relative concentration of glutathione in different organelles of Arabidopsis thaliana leaf and root cells. Glutathione-specific labelling was detected in all cellular compartments except the apoplast and the vacuole. The highest glutathione content was surprisingly not found in plastids, which have been described before as a major site of glutathione accumulation, but in mitochondria which lack the capacity for glutathione biosynthesis. Mitochondria of both leaf and root cells contained 7-fold and 4-fold, respectively, higher glutathione levels than plastids while the density of glutathione labelling in the cytosol, nuclei, and peroxisomes was intermediate. The accuracy of the glutathione labelling is supported by two observations. First, pre-adsorption of the anti-glutathione antisera with glutathione reduced the density of the gold particles in all organelles to background levels. Second, the overall glutathione-labelling density was reduced by about 90% in leaves of the glutathione-deficient Arabidopsis mutant pad2-1 and increased in transgenic plants with enhanced glutathione accumulation. Hence, there was a strong correlation between immunocytochemical and biochemical data of glutathione accumulation. Interestingly, the glutathione labelling of mitochondria in pad2-1 remained very similar to wild-type plants thus suggesting that the high mitochondrial glutathione content is maintained in a situation of permanent glutathione-deficiency at the expense of other glutathione pools. High and constant levels of glutathione in mitochondria appear to be particularly

  5. Neuroprotection and Anti-Epileptogenesis with Mitochondria-Targeted Antioxidant

    Science.gov (United States)

    2016-06-01

    Award Number: W81XWH-12-1-0258 TITLE: Neuroprotection and Anti-Epileptogenesis with Mitochondria -Targeted Antioxidant PRINCIPAL INVESTIGATOR...SUBTITLE Neuroprotection and Anti-Epileptogenesis with Mitochondria -Targeted Antioxidant 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-12-1-0258 5c

  6. Traveling Bax and Forth from Mitochondria to Control Apoptosis

    Science.gov (United States)

    Soriano, Maria Eugenia; Scorrano, Luca

    2011-01-01

    Antiapoptotic Bcl-2 proteins on mitochondria inhibit prodeath proteins, such as Bax, which are found primarily in the cytosol. In this issue, Edlich et al., (2011) show that Bax and Bcl-xL interact on the mitochondrial surface and then retrotranslocate to the cytosol, effectively preventing Bax-induced permeabilization of mitochondria. PMID:21458662

  7. Activity and functional interaction of alternative oxidase and uncoupling protein in mitochondria from tomato fruit

    Directory of Open Access Journals (Sweden)

    F.E. Sluse

    2000-03-01

    Full Text Available Cyanide-resistant alternative oxidase (AOX is not limited to plant mitochondria and is widespread among several types of protists. The uncoupling protein (UCP is much more widespread than previously believed, not only in tissues of higher animals but also in plants and in an amoeboid protozoan. The redox energy-dissipating pathway (AOX and the proton electrochemical gradient energy-dissipating pathway (UCP lead to the same final effect, i.e., a decrease in ATP synthesis and an increase in heat production. Studies with green tomato fruit mitochondria show that both proteins are present simultaneously in the membrane. This raises the question of a specific physiological role for each energy-dissipating system and of a possible functional connection between them (shared regulation. Linoleic acid, an abundant free fatty acid in plants which activates UCP, strongly inhibits cyanide-resistant respiration mediated by AOX. Moreover, studies of the evolution of AOX and UCP protein expression and of their activities during post-harvest ripening of tomato fruit show that AOX and plant UCP work sequentially: AOX activity decreases in early post-growing stages and UCP activity is decreased in late ripening stages. Electron partitioning between the alternative oxidase and the cytochrome pathway as well as H+ gradient partitioning between ATP synthase and UCP can be evaluated by the ADP/O method. This method facilitates description of the kinetics of energy-dissipating pathways and of ATP synthase when state 3 respiration is decreased by limitation of oxidizable substrate.

  8. The circular F-actin bundles provide a track for turnaround and bidirectional movement of mitochondria in Arabidopsis root hair.

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    Full Text Available The movement of organelles in root hairs primarily occurs along the actin cytoskeleton. Circulation and "reverse fountain" cytoplasmic streaming constitute the typical forms by which most organelles (such as mitochondria and the Golgi apparatus in plant root hair cells engage in bidirectional movement. However, there remains a lack of in-depth research regarding the relationship between the distribution of the actin cytoskeleton and turnaround organelle movement in plant root hair cells.In this paper, Arabidopsis seedlings that had been stably transformed with a GFP-ABD2-GFP (green fluorescent protein-actin-binding domain 2-green fluorescent protein construct were utilized to study the distribution of bundles of filamentous (F-actin and the directed motion of mitochondria along these bundles in root hairs. Observations with a confocal laser scanning microscope revealed that there were widespread circular F-actin bundles in the epidermal cells and root hairs of Arabidopsis roots. In root hairs, these circular bundles primarily start at the sub-apical region, which is the location where the turnaround movement of organelles occurs. MitoTracker probes were used to label mitochondria, and the dynamic observation of root hair cells with a confocal laser scanning microscope indicated that turnaround mitochondrial movement occurred along circular F-actin bundles.Relevant experimental results demonstrated that the circular F-actin bundles provide a track for the turnaround and bidirectional movement of mitochondria.

  9. Mitochondria in health, aging and diseases: the epigenetic perspective.

    Science.gov (United States)

    D'Aquila, Patrizia; Bellizzi, Dina; Passarino, Giuseppe

    2015-10-01

    The rate/quality of human aging and the development/progression of diseases depend on a complex interplay among genetics, epigenetics and environment. In this scenario, mitochondrial function (or dysfunction) and mitochondrial DNA have emerged as major players. This is mainly due to their crucial role in energetic balance, in modulating epigenetic programs and in influencing cell stress response. Moreover, it is also emerging the existence of epigenetic changes in mitochondrial DNA and of non coding mitochondrial RNAs which, together with the nuclear ones, play regulatory roles in numerous human phenotypes. In this review we will provide an overview on "mitochondrial epigenetics" state of the art, by summarizing the involvement of mitochondrial function and of mitochondria-nucleus communication in regulating nuclear epigenome, as well as the key aspects of the epigenetic marks related to mitochondrial DNA. Despite the limited data available in the literature to date, mainly due to the novelty of the topic, the intriguing interplay of the mitochondrial epigenetic changes in both physiological and pathological conditions will also be presented.

  10. Research Progress on Application and Extraction Method of Plant Volatile Oils%植物挥发油提取方法及应用研究进展

    Institute of Scientific and Technical Information of China (English)

    张志军; 刘西亮; 李会珍; 刘培培; 张鑫

    2011-01-01

    The extraction of essential oils from plants not only is of practical use for industrial production of perfume, food and cosmetic product, but also is quite significant for human healthcare.In this paper, traditional extraction methods, such as steam distillation, solvent extraction, oil adsorption and mechanical pressing, were summarized,and the research progresses on several modern technologies, applied recently in plant essential oil extraction, were also reviewed, including enzymatic, CO2 supercritical fluid, sub - critical water, ultrasound - assisted, microwave accelerated distillation, simultaneous distillation, microcapsule aqueous two- phase and solid phase micro- extraction.%提取植物挥发油不仅对香料、食品、日用化妆品工业生产具有实用价值,而且对人类保健也有重要意义.本文总结回顾了水蒸气蒸馏,溶剂萃取,油脂吸收,压榨法等植物挥发油传统提取方法,并综述了多种现代分离技术在植物油提取中的应用研究进展,主要包括酶法、C02超临界流体萃取、亚临界水萃取、超声波辅助提取、微波辐射、微胶囊一双水相萃取、同时蒸馏萃取及固相萃取等技术.

  11. The Progress of Molecular Mechanisms of Photorespiration in Plants%植物光呼吸分子机制研究进展

    Institute of Scientific and Technical Information of China (English)

    金怡; 刘合芹; 汪得凯; 陶跃之

    2011-01-01

    光呼吸是植物的绿色细胞在光照下吸收O2释放CO2的反应,光呼吸强弱是影响C3和C4植物光合效率高低的重要因素.对光呼吸的分子机理研究是光合作用研究的热点之一.本文就光呼吸的代谢途径、光呼吸基因表达调控及光呼吸突变体的筛选等方面的研究进展进行了阐述.对光呼吸的生物学功能进行了探讨,并对光呼吸领域的发展进行了展望.%Photorespiration is known as the light-dependent absorption of the O2 and release of CO2 response by plant green cells, whose strength is an important factor affect the level of the photosynthetic efficiency of C3 and C4 plants. The study of the molecular mechanism of photorespiration is one of the hot-topics of research on photosynthesis. In the article, the research on photorespiratory metabolic pathways, the expression and regulation of photorespiratory genes and the progress of screen of photorespiration mutants were summarized.The biological function of photorespiration was discussed and the prospect of photorespiration was also provided.

  12. Lipid droplets interact with mitochondria using SNAP23

    DEFF Research Database (Denmark)

    Jägerström, Sara; Polesie, Sam; Wickström, Ylva

    2009-01-01

    factors are involved. Moreover, the presence of LD markers in mitochondria isolated by subcellular fractionations is demonstrated. Finally, ablation of SNAP23 using siRNA reduced complex formation and beta oxidation, which suggests that the LD-mitochondria complex is functional in the cell.......Triglyceride-containing lipid droplets (LD) are dynamic organelles stored on demand in all cells. These droplets grow through a fusion process mediated by SNARE proteins, including SNAP23. The droplets have also been shown to be highly motile and interact with other cell organelles, including...... peroxisomes and the endoplasmic reticulum. We have used electron and confocal microscopy to demonstrate that LD form complexes with mitochondria in NIH 3T3 fibroblasts. Using an in vitro system of purified LD and mitochondria, we also show the formation of the LD-mitochondria complex, in which cytosolic...

  13. Mitochondrial endonuclease G mediates breakdown of paternal mitochondria upon fertilization.

    Science.gov (United States)

    Zhou, Qinghua; Li, Haimin; Li, Hanzeng; Nakagawa, Akihisa; Lin, Jason L J; Lee, Eui-Seung; Harry, Brian L; Skeen-Gaar, Riley Robert; Suehiro, Yuji; William, Donna; Mitani, Shohei; Yuan, Hanna S; Kang, Byung-Ho; Xue, Ding

    2016-07-22

    Mitochondria are inherited maternally in most animals, but the mechanisms of selective paternal mitochondrial elimination (PME) are unknown. While examining fertilization in Caenorhabditis elegans, we observed that paternal mitochondria rapidly lose their inner membrane integrity. CPS-6, a mitochondrial endonuclease G, serves as a paternal mitochondrial factor that is critical for PME. We found that CPS-6 relocates from the intermembrane space of paternal mitochondria to the matrix after fertilization to degrade mitochondrial DNA. It acts with maternal autophagy and proteasome machineries to promote PME. Loss of cps-6 delays breakdown of mitochondrial inner membranes, autophagosome enclosure of paternal mitochondria, and PME. Delayed removal of paternal mitochondria causes increased embryonic lethality, demonstrating that PME is important for normal animal development. Thus, CPS-6 functions as a paternal mitochondrial degradation factor during animal development.

  14. BCL-2 family proteins as regulators of mitochondria metabolism.

    Science.gov (United States)

    Gross, Atan

    2016-08-01

    The BCL-2 family proteins are major regulators of apoptosis, and one of their major sites of action are the mitochondria. Mitochondria are the cellular hubs for metabolism and indeed selected BCL-2 family proteins also possess roles related to mitochondria metabolism and dynamics. Here we discuss the link between mitochondrial metabolism/dynamics and the fate of stem cells, with an emphasis on the role of the BID-MTCH2 pair in regulating this link. We also discuss the possibility that BCL-2 family proteins act as metabolic sensors/messengers coming on and off of mitochondria to "sample" the cytosol and provide the mitochondria with up-to-date metabolic information. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Three Toxic Gases Meet in the Mitochondria

    Directory of Open Access Journals (Sweden)

    Richard A Decreau

    2015-08-01

    Full Text Available The rationale of the study was two-fold : (i develop a functional synthetic model of the Cytochrome c oxidase (CcO active site, (ii use it as a convenient tool to understand or predict the outcome of the reaction of CcO with ligands (physiologically relevant gases and other ligands. At physiological pH and potential, the model catalyzes the 4-electron reduction of oxygen. This model was immobilized on self-assembled-monolayer (SAM modified electrode. During catalytic oxygen reduction, electron delivery through SAMs is rate limiting, similar to the situation in CcO. This model contains all three redox-active components in CcO’s active site, which are required to minimize the production of partially-reduced-oxygen-species (PROS: Fe¬-heme (heme a3 in a myoglobin-like model fitted with a proximal imidazole ligand, and a distal tris-imidazole Copper (CuB complex, where one imidazole is cross-linked to a phenol (mimicking Tyr244. This functional CcO model demonstrates how CcO itself might tolerate the hormone NO (which diffuses through the mitochondria. It is proposed that CuB delivers superoxide to NO bound to Fe-heme forming peroxynitrite, then nitrate that diffuses away. Another toxic gas, H2S, has exceptional biological effects: at ~80 ppm, H2S induces a state similar to hibernation in mice, lowering the animal's temperature and slowing respiration. Using our functional CcO model, we have demonstrated that at the same concentration range H2S can reversibly inhibit catalytic oxygen reduction. Such a reversible catalytic process on the model was also demonstrated with an organic compound, tetrazole (TZ. Following studies showed that TZ reversibly inhibits respiration in isolated mitochondria, and induces deactivation of platelets, a mitochondria-rich key component of blood coagulation. Hence, this program is a rare example illustrating the use of a functional model to understand and predict physiologically important reactions at the active site

  16. SIRT3 deacetylates FOXO3 to protect mitochondria against oxidative damage.

    Science.gov (United States)

    Tseng, Anne H H; Shieh, Shyan-Shu; Wang, Danny Ling

    2013-10-01

    Progressive accumulation of defective mitochondria is a common feature of aged cells. SIRT3 is a NAD(+)-dependent protein deacetylase that regulates mitochondrial function and metabolism in response to caloric restriction and stress. FOXO3 is a direct target of SIRT3 and functions as a forkhead transcription factor to govern diverse cellular responses to stress. Here we show that hydrogen peroxide induces SIRT3 to deacetylate FOXO3 at K271 and K290, followed by the upregulation of a set of genes that are essential for mitochondrial homeostasis (mitochondrial biogenesis, fission/fusion, and mitophagy). Consequently, SIRT3-mediated deacetylation of FOXO3 modulates mitochondrial mass, ATP production, and clearance of defective mitochondria. Thus, mitochondrial quantity and quality are ensured to maintain mitochondrial reserve capacity in response to oxidative damage. Maladaptation to oxidative stress is a major risk factor underlying aging and many aging-related diseases. Hence, our finding that SIRT3 deacetylates FOXO3 to protect mitochondria against oxidative stress provides a possible direction for aging-delaying therapies and disease intervention.

  17. Mitochondria: A crossroads for lipid metabolism defect in neurodegeneration with brain iron accumulation diseases.

    Science.gov (United States)

    Aoun, Manar; Tiranti, Valeria

    2015-06-01

    Neurodegeneration with brain iron accumulation (NBIA) comprises a group of brain iron deposition syndromes that lead to mixed extrapyramidal features and progressive dementia. Exact pathologic mechanism of iron deposition in NBIA remains unknown. However, it is becoming increasingly evident that many neurodegenerative diseases are hallmarked by metabolic dysfunction that often involves altered lipid profile. Among the identified disease genes, four encode for proteins localized in mitochondria, which are directly or indirectly implicated in lipid metabolism: PANK2, CoASY, PLA2G6 and C19orf12. Mutations in PANK2 and CoASY, both implicated in CoA biosynthesis that acts as a fatty acyl carrier, lead, respectively, to PKAN and CoPAN forms of NBIA. Mutations in PLA2G6, which plays a key role in the biosynthesis and remodeling of membrane phospholipids including cardiolipin, lead to PLAN. Mutations in C19orf12 lead to MPAN, a syndrome similar to that caused by mutations in PANK2 and PLA2G6. Although the function of C19orf12 is largely unknown, experimental data suggest its implication in mitochondrial homeostasis and lipid metabolism. Altogether, the identified mutated proteins localized in mitochondria and associated with different NBIA forms support the concept that dysfunctions in mitochondria and lipid metabolism play a crucial role in the pathogenesis of NBIA. This article is part of a Directed Issue entitled: Energy Metabolism Disorders and Therapies.

  18. Mitochondria are linked to calcium stores in striated muscle by developmentally regulated tethering structures.

    Science.gov (United States)

    Boncompagni, Simona; Rossi, Ann E; Micaroni, Massimo; Beznoussenko, Galina V; Polishchuk, Roman S; Dirksen, Robert T; Protasi, Feliciano

    2009-02-01

    Bi-directional calcium (Ca(2+)) signaling between mitochondria and intracellular stores (endoplasmic/sarcoplasmic reticulum) underlies important cellular functions, including oxidative ATP production. In striated muscle, this coupling is achieved by mitochondria being located adjacent to Ca(2+) stores (sarcoplasmic reticulum [SR]) and in proximity of release sites (Ca(2+) release units [CRUs]). However, limited information is available with regard to the mechanisms of mitochondrial-SR coupling. Using electron microscopy and electron tomography, we identified small bridges, or tethers, that link the outer mitochondrial membrane to the intracellular Ca(2+) stores of muscle. This association is sufficiently strong that treatment with hypotonic solution results in stretching of the SR membrane in correspondence of tethers. We also show that the association of mitochondria to the SR is 1) developmentally regulated, 2) involves a progressive shift from a longitudinal clustering at birth to a specific CRU-coupled transversal orientation in adult, and 3) results in a change in the mitochondrial polarization state, as shown by confocal imaging after JC1 staining. Our results suggest that tethers 1) establish and maintain SR-mitochondrial association during postnatal maturation and in adult muscle and 2) likely provide a structural framework for bi-directional signaling between the two organelles in striated muscle.

  19. 植物抗病机制的研究进展%Research Progress on the Mechanism of Plant Disease Resistance

    Institute of Scientific and Technical Information of China (English)

    杨银; 高志勇

    2016-01-01

    ), it can directly or indirectly to the identification of pathogenic bacteria release effect factor and effector triggered immunity in-duced by plant cell active death, namely hypersensitive response (Hypersensitive response HR), thereby inhibiting pathogenic bac-teria infection. Through genomic analysis, there are about 125 plant disease resistance genes in Arabidopsis, but only RPM1 and rps2 and a few other resistance gene function get reported, and the study of plant disease resistance signaling pathways is not very clear. This is because of the traditional genetics analysis method to study plant disease resistance genes of functional limitations, causing the main reason for this limitation is killed because of plant disease resistance genes are functionally redundant and involved in plant disease resistance signal transduction through the upstream and downstream gene deletion. The research progress of plant disease re-sistance mechanism in recent years is reviewed, and the main problems in this field are also introduced.

  20. Mitochondria as a target for neuroprotection: implications for Alzheimer´s disease.

    Science.gov (United States)

    Cardoso, Susana; Seiça, Raquel M; Moreira, Paula I

    2017-01-01

    Alzheimer's disease (AD), the most common form of dementia, is marked by progressive loss of memory and impairment of cognitive ability. Despite decades of intensive research and scientific advances, the intricate pathogenic mechanisms of AD are still not fully understood and, consequently, an effective treatment is yet to be developed. As widely accepted, the alterations of mitochondrial function are actively engaged in a plethora of neurodegenerative diseases, including AD. With growing interest in the mitochondria as a potential target for understanding AD, it has even been hypothesized that deficits in these organelles may be at the heart of the progression of AD itself. Areas covered: The purpose of this review is to summarize relevant studies that suggest a role for mitochondrial (dys)function in AD and to provide a survey on latest developments regarding AD-related mitochondrial therapeutics. Expert commentary: As outlined in a plethora of studies, there is no doubt that mitochondria play a major role in several stages of AD progression. Even though more in-depth studies are needed before pharmaceutical industry can apply such knowledge to human medicine, the continuous advances in AD research field will certainly facilitate and accelerate the development of more effective preventive or therapeutic strategies to fight this devastating disease.

  1. Origins of prokaryotes, eukaryotes, mitochondria, and chloroplasts

    Science.gov (United States)

    Schwartz, R. M.; Dayhoff, M. O.

    1978-01-01

    A computer branching model is used to analyze cellular evolution. Attention is given to certain key amino acids and nucleotide residues (ferredoxin, 5s ribosomal RNA, and c-type cytochromes) because of their commonality over a wide variety of cell types. Each amino acid or nucleotide residue is a sequence in an inherited biological trait; and the branching method is employed to align sequences so that changes reflect substitution of one residue for another. Based on the computer analysis, the symbiotic theory of cellular evolution is considered the most probable. This theory holds that organelles, e.g., mitochondria and chloroplasts invaded larger bodies, e.g., bacteria, and combined functions to form eucaryotic cells.

  2. Modelling the ATP production in mitochondria

    CERN Document Server

    Saa, Alberto

    2012-01-01

    We revisit here the mathematical model for ATP production in mitochondria introduced recently by Bertram, Pedersen, Luciani, and Sherman (BPLS) as a simplification of the more complete but intricate Magnus and Keizer's model. We correct some inaccuracies in the BPLS original approximations and then analyze some of the dynamical properties of the model. We infer from exhaustive numerical explorations that the enhanced BPLS equations have a unique attractor fixed point for physiologically acceptable ranges of mitochondrial variables and respiration inputs. We determine, in the stationary regime, the dependence of the mitochondrial variables on the respiration inputs, namely the cytosolic concentration of calcium ${\\rm Ca}_{\\rm c}$ and the substrate fructose 1,6-bisphosphate FBP. The same effect of calcium saturation reported for the original BPLS model is observed here. We find out, however, an interesting non-stationary effect: the inertia of the model tends to increase considerably for high concentrations of ...

  3. Lactate oxidation in human skeletal muscle mitochondria

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Meinild, Anne-Kristine; Nordsborg, Nikolai B

    2013-01-01

    Lactate is an important intermediate metabolite in human bioenergetics and is oxidized in many different tissues including the heart, brain, kidney, adipose tissue, liver, and skeletal muscle. The mechanism(s) explaining the metabolism of lactate in these tissues, however, remains unclear. Here, we...... analyze the ability of skeletal muscle to respire lactate by using an in situ mitochondrial preparation that leaves the native tubular reticulum and subcellular interactions of the organelle unaltered. Skeletal muscle biopsies were obtained from vastus lateralis muscle in 16 human subjects. Samples were...... of exogenous LDH failed to increase lactate-stimulated respiration (P = 1.0). The results further demonstrate that human skeletal muscle mitochondria cannot directly oxidize lactate within the mitochondrial matrix. Alternately, these data support previous claims that lactate is converted to pyruvate within...

  4. Apoptosis in Drosophila: which role for mitochondria?

    Science.gov (United States)

    Clavier, Amandine; Rincheval-Arnold, Aurore; Colin, Jessie; Mignotte, Bernard; Guénal, Isabelle

    2016-03-01

    It is now well established that the mitochondrion is a central regulator of mammalian cell apoptosis. However, the importance of this organelle in non-mammalian apoptosis has long been regarded as minor, mainly because of the absence of a crucial role for cytochrome c in caspase activation. Recent results indicate that the control of caspase activation and cell death in Drosophila occurs at the mitochondrial level. Numerous proteins, including RHG proteins and proteins of the Bcl-2 family that are key regulators of Drosophila apoptosis, constitutively or transiently localize in mitochondria. These proteins participate in the cell death process at different levels such as degradation of Diap1, a Drosophila IAP, production of mitochondrial reactive oxygen species or stimulation of the mitochondrial fission machinery. Here, we review these mitochondrial events that might have their counterpart in human.

  5. [Thiamine triphosphatase activity in mammalian mitochondria].

    Science.gov (United States)

    Rusina, I M; Makarchikov, A F

    2003-01-01

    Mitochondrial preparations isolated from bovine kidney and brain as well as the liver and the brain of rat show thiamine triphosphatase (ThTPase) activity. The activity was determined from the particles by freezing-thawing suggesting that a soluble enzyme is involved. The liberation patterns of ThTPase and marker enzyme activities from mitochondria under osmotic shock or treatment with increasing Triton X-100 concentrations indicate the presence of ThTPase both in the matrix and intermembrane space. It was found, basing on gel filtration behavior, that the mitochondrial ThTPase has the same molecular mass as specific cytosolic ThTPase (EC 3.6.1.28). The enzymes, however, were clearly distinguishable in Km values, the mitochondrial one showing a higher apparent affinity for substrate. These results imply the existence of ThTPase multiple forms in mammalian cells.

  6. Fetal programming of atherosclerosis: possible role of the mitochondria.

    Science.gov (United States)

    Leduc, Line; Levy, Emile; Bouity-Voubou, Maurice; Delvin, Edgard

    2010-04-01

    Growing evidence indicates that being small size at birth from malnutrition is associated with an increased risk of developing type 2 diabetes (T2D), metabolic syndrome and cardiovascular disease in adulthood. Atherosclerosis is common to these aforementioned disorders, and oxidative stress and chronic inflammation are now considered as initiating events in its development, with endothelial cell dysfunction being an early, fundamental step. According to the fetal programming hypothesis, growth-restricted neonates exposed to placental insufficiency exhibit endothelial cell dysfunction very early in life that later on predisposes them to atherosclerosis. Although many investigations have reported early alterations in vascular function in children and adolescents with low birth weight, the mechanisms of such fetal programming of atherosclerosis remain largely unknown. Experimental studies have demonstrated that low birth weight infants are prenatally subjected to conditions of oxidative stress and inflammation that might be involved in the later occurrence of atherosclerosis. Arterial endothelial dysfunction has been encountered in term infants, children and young adults with low birth weight. The loss of appropriate endothelium function with decreased nitric oxide production or activity, manifested as impaired vasodilatation, is considered a basic step in atherosclerosis development and progression. Several lines of evidence indicate that mitochondrial damage is central to this process and that reactive oxygen species (ROS) may act as a double-edged sword. On the one hand, it is well-accepted that the mitochondria are a major source of chronic ROS production under physiological conditions. On the other hand, it is known that ROS generation damages lipids, proteins and mitochondrial DNA, leading to dysregulated mitochondrial function. Elevated mitochondrial ROS production is associated with endothelial cell dysfunction as well as vascular smooth muscle cell

  7. Progresses of Molecular Markers Application in Invasive Plant Research%分子标记在入侵植物研究中的应用

    Institute of Scientific and Technical Information of China (English)

    王从彦; 刘雪艳; 杜道林

    2013-01-01

    入侵植物给入侵地的生态系统造成了多重影响,而入侵生态学研究对探析入侵植物成功入侵的机制及其可持续控制具有重要的理论和实际意义.分子标记作为一种基于DNA水平的遗传分析技术,为解决入侵生态学研究的许多基本问题提供了很好的手段与平台.基于此,简要综述了分子标记技术在入侵植物遗传多样性分析、入侵机制及入侵模式探究等方面的应用研究进展.%Invasive species can cause multiple effects on national ecosystems. The research of invasion ecology is of significance in understanding the invasion mechanisms of invasive species and in developing corresponding sustainable control methods. Molecular marker has been used to approach some essential issues in the research of invasion ecology as a useful tool base at DNA level. In this paper,the research progresses of molecular marker application in genetic diversities, invasion mechanisms,and spread pattern of invasive plants were reviewed to provide the relevant theoretical base for the further study.

  8. The involvement of PUMP from mitochondria of Araucaria angustifolia embryogenic cells in response to cold stress.

    Science.gov (United States)

    Valente, Caroline; Pasqualim, Patrícia; Jacomasso, Thiago; Maurer, Juliana Bello Baron; Souza, Emanuel Maltempi de; Martinez, Glaucia Regina; Rocha, Maria Eliane Merlin; Carnieri, Eva Gunilla Skare; Cadena, Sílvia Maria Suter Correia

    2012-12-01

    In this study, the responses of plant uncoupling mitochondrial protein (PUMP) and alternative oxidase (AOX) in mitochondria from embryogenic cells of A. angustifolia subjected to cold stress (4°C for 24 h or 48 h) is reported. In the mitochondria of stressed cells, PUMP activity increased by approximately 45% (at 24h and 48 h), which was determined by measuring the oxygen consumption after the addition of linoleic acid and the inhibition by BSA and ATP. PUMP activation was confirmed using transmembrane electrical potential (Δψ) assays. Immunoblot assays showed an increase of PUMP expression by 40% and 150% after 24h and 48 h of cold stress, respectively. AOX activity, measured under conditions similar to those of the PUMP assays, was only slightly increased in the mitochondria from stressed cells (at 24h and 48 h), as demonstrated by oxygen consumption experiments. Cell viability was unaffected by cold stress, indicating that the effects on PUMP and AOX were not caused by cell death. These results show that the main response of this gymnosperm to cold stress is the activation of PUMP, which suggests that this protein may be involved in the control of reactive oxygen species generation, which has been previously associated with this condition.

  9. Damage of oxidative stress on mitochondria during microspores development in Honglian CMS line of rice.

    Science.gov (United States)

    Wan, Cuixiang; Li, Shaoqing; Wen, Li; Kong, Jin; Wang, Kun; Zhu, Yingguo

    2007-03-01

    One of the cytoplasmic male sterility (CMS) types used for hybrid rice (Oryza sativa L.) production in China is the Honglian (HL)-CMS. Previous studies suggested that pollen abortion of the sterile plants was resulted from a special programmed cell death (PCD) program started at meiosis in the microspores. To elucidate the molecular basis of the pollen abortion, we compared the biochemical and physiological properties such as content of reactive oxygen species (ROS), ATP, NADH, total glutathione and ascorbate acid, the activities of dehydroascrbate reductase, glutathione reductase, ascorbate peroxides and superoxide dismutase, and the integrity of mitochondrial genome DNA isolated from an HL-CMS line, Yuetai A and its maintainer line, Yuetai B. Our results indicated that the mitochondria of the HL-CMS line suffered from a serious oxidative stress during microspores development. Oxidative stress induced by abnormal increased ROS at meiosis stage resulted in the depletion of ATP and NADH, and the degradation of mitochondrial genomic DNA. This suggests that the presence of redox signal originated in mitochondria affects the rest of the cell. Therefore, it is possible that the abortion of premature microspores in HL-CMS line is induced by the chronic oxidative stress in mitochondria in the early stage of pollen development.

  10. Research Progress in Aggregation Structure of Recycled Plant Fiber%二次纤维聚集态结构的研究进展

    Institute of Scientific and Technical Information of China (English)

    马邕文; 吕惠琳; 王艳; 万金泉

    2012-01-01

    为了研究二次纤维的角质化机理并提出抑制方法,实现二次纤维的高效绿色循环利用,综述了基于共结晶角质化机理的纤维素聚集态结构的研究现状和进展,介绍了纤维素聚集态结构模型和氢键链接方式,着重介绍了目前纤维素聚集态结构研究和氢键研究的进展,综述了目前纤维素聚集态研究手段的多样化:计算机分子模拟、广角X衍射衍射(XRD)、交叉极化/魔角旋转固体核磁共振13C(CP/MAS13C NMR),同步辐射XRD衍射、中子衍射和傅里叶红外(FT-IR)。研究内容从对天然纤维素的基本建模深入到分子链水平的原子链接、氢键模式的研究,研究手段经历了从使用单一仪器发展到多种仪器手段辅助表征的过程。纤维素聚集态结构的研究将是二次纤维角质化机理研究以及纤维素化学研究的重要课题。%In order to elaborate the mechanisms and reasons of hornification which affects the properties of recycled plant fibers,then to realize efficient utilization of recycled plant fibers,this article reviews: research status and progress of the cellulose aggregation structure based on the mechanism of cocrystallization;the aggregation structure model and hydrogen bond linkage,especially natural cellulose crystal structure and the research progress of hydrogen bond;diversity in the research methods of cellulose supermolecules: computer molecular simulation,wide angle X-ray diffraction(XRD),solid-state cross polarisation magic angle spinning carbon-13 nuclear magnetic resonance(CP/MAS 13C NMR),synchrotron radiation X-ray diffraction(XRD),neutron diffraction and Fourier transform infra-red spectroscopy(FT-IR).The study goes deep into the molecular chain modeling of hydrogen atoms links in content and the application of auxiliary characterization in instrument means.Research of cellulose aggregation structure is an important subject of honification in recycled plant fibers and

  11. Mitochondrial drug delivery and mitochondrial disease therapy--an approach to liposome-based delivery targeted to mitochondria.

    OpenAIRE

    Yamada, Yuma; Akita, Hidetaka; Kogure, Kentaro; Kamiya, Hiroyuki; Harashima, Hideyoshi

    2007-01-01

    Recent progress in genetics and molecular biology has provided useful information regarding the molecular mechanisms associated with the mitochondrial diseases. Genetic approaches were initiated in the late 1980s to clarify the gene responsible for various mitochondrial diseases, and information concerning genetic mutations is currently used in the diagnosis of mitochondrial diseases. Moreover, it was also revealed that mitochondria play a central role in apoptosis, or programmed cell death, ...

  12. Improved method for isolation of coupled mitochondria of Araucaria angustifolia (Bert. O. Kuntze

    Directory of Open Access Journals (Sweden)

    André Bellin Mariano

    2004-11-01

    Full Text Available A method for the isolation of coupled mitochondria from the callus of Araucaria angustifolia is described for the first time. Mitochondria were isolated from embryogenic callus of A. angustifolia. They were metabolically active, able to sustain oxidative phosphorylation as shown by respiratory control ratio values, which were about 2.4 when respiring on succinate as substrate. Oxygen uptake experiments, using freeze-thawed disrupted mitochondria, showed the presence of alternative rotenone-insensitive NAD(PH dehydrogenases, which were stimulated by Ca2+. The procedure now described for the isolation of A. angustifolia mitochondria is an important new tool, allowing the investigation of mitochondrial bioenergetics and metabolism and physiology of plants.Um procedimento de isolamento de mitocôndrias funcionalmente intactas de calos embriogênicos de Araucaria angustifolia foi desenvolvido pela primeira vez em nosso laboratório. Mitocôndrias isoladas por este método são metabolicamente ativas, capazes de sustentar fosforilação oxidativa como mostrado pelo controle respiratório de aproximadamente 2,4, respirando na presença de succinato como substrato. Através de experimentos de consumo de oxigênio com mitocôndrias rompidas em nitrogênio líquido foi demonstrada a presença de NAD(PH desidrogenases alternativas, insensíveis à rotenona e estimuladas por Ca2+. O isolamento de mitocôndrias de A. angustifolia é um novo e importante instrumento para estudar plantas, permitindo a execução de múltiplas investigações a respeito da bioenergética mitocondrial e fisiologia vegetal.

  13. Metabolic integration during the evolutionary origin of mitochondria

    Institute of Scientific and Technical Information of China (English)

    DENNIS G SEARCY

    2003-01-01

    Although mitochondria provide eukaryotic cells with certain metabolic advantages, in other ways they may be disadvantageous. For example, mitochondria produce reactive oxygen species that damage both nucleocytoplasm and mitochondria, resulting in mutations, diseases, and aging. The relationship of mitochondria to the cytoplasm is best understood in the context of evolutionary history. Although it is clear that mitochondria evolved from symbiotic bacteria, the exact nature of the initial symbiosis is a matter of continuing debate. The exchange of nutrients between host and symbiont may have differed from that between the cytoplasm and mitochondria in modern cells. Speculations about the initial relationships include the following. (1) The pre-mitochondrion may have been an invasive, parasitic bacterium. The host did not benefit. (2) The relationship was a nutritional syntrophy based upon transfer of organic acids from host to symbiont. (3) The relationship was a syntrophy based upon H2 transfer from symbiont to host, where the host was a methanogen. (4) There was a syntrophy based upon reciprocal exchange of sulfur compounds.The last conjecture receives support from our detection in eukaryotic cells of substantial H2S-oxidizing activity in mitochondria, and sulfur-reducing activity in the cytoplasm.

  14. Reactive oxygen species and mitochondria: A nexus of cellular homeostasis.

    Science.gov (United States)

    Dan Dunn, Joe; Alvarez, Luis Aj; Zhang, Xuezhi; Soldati, Thierry

    2015-12-01

    Reactive oxygen species (ROS) are integral components of multiple cellular pathways even though excessive or inappropriately localized ROS damage cells. ROS function as anti-microbial effector molecules and as signaling molecules that regulate such processes as NF-kB transcriptional activity, the production of DNA-based neutrophil extracellular traps (NETs), and autophagy. The main sources of cellular ROS are mitochondria and NADPH oxidases (NOXs). In contrast to NOX-generated ROS, ROS produced in the mitochondria (mtROS) were initially considered to be unwanted by-products of oxidative metabolism. Increasing evidence indicates that mtROS have been incorporated into signaling pathways including those regulating immune responses and autophagy. As metabolic hubs, mitochondria facilitate crosstalk between the metabolic state of the cell with these pathways. Mitochondria and ROS are thus a nexus of multiple pathways that determine the response of cells to disruptions in cellular homeostasis such as infection, sterile damage, and metabolic imbalance. In this review, we discuss the roles of mitochondria in the generation of ROS-derived anti-microbial effectors, the interplay of mitochondria and ROS with autophagy and the formation of DNA extracellular traps, and activation of the NLRP3 inflammasome by ROS and mitochondria. Copyright © 2015. Published by Elsevier B.V.

  15. Mitochondria localize to the cleavage furrow in mammalian cytokinesis.

    Science.gov (United States)

    Lawrence, Elizabeth J; Mandato, Craig A

    2013-01-01

    Mitochondria are dynamic organelles with multiple cellular functions, including ATP production, calcium buffering, and lipid biosynthesis. Several studies have shown that mitochondrial positioning is regulated by the cytoskeleton during cell division in several eukaryotic systems. However, the distribution of mitochondria during mammalian cytokinesis and whether the distribution is regulated by the cytoskeleton has not been examined. Using live spinning disk confocal microscopy and quantitative analysis of mitochondrial fluorescence intensity, we demonstrate that mitochondria are recruited to the cleavage furrow during cytokinesis in HeLa cells. After anaphase onset, the mitochondria are recruited towards the site of cleavage furrow formation, where they remain enriched as the furrow ingresses and until cytokinesis completion. Furthermore, we show that recruitment of mitochondria to the furrow occurs in multiple mammalian cells lines as well as in monopolar, bipolar, and multipolar divisions, suggesting that the mechanism of recruitment is conserved and robust. Using inhibitors of cytoskeleton dynamics, we show that the microtubule cytoskeleton, but not actin, is required to transport mitochondria to the cleavage furrow. Thus, mitochondria are specifically recruited to the cleavage furrow in a microtubule-dependent manner during mammalian cytokinesis. Two possible reasons for this could be to localize mitochondrial function to the furrow to facilitate cytokinesis and / or ensure accurate mitochondrial inheritance.

  16. Stable Isotope Tracer Analysis in Isolated Mitochondria from Mammalian Systems

    Directory of Open Access Journals (Sweden)

    Simon-Pierre Gravel

    2014-04-01

    Full Text Available Mitochondria are a focal point in metabolism, given that they play fundamental roles in catabolic, as well as anabolic reactions. Alterations in mitochondrial functions are often studied in whole cells, and metabolomics experiments using 13C-labeled substrates, coupled with mass isotopomer distribution analyses, represent a powerful approach to study global changes in cellular metabolic activities. However, little is known regarding the assessment of metabolic activities in isolated mitochondria using this technology. Studies on isolated mitochondria permit the evaluation of whether changes in cellular metabolic activities are due to modifications in the intrinsic properties of the mitochondria. Here, we present a streamlined approach to accurately determine 13C, as well as 12C enrichments in isolated mitochondria from mammalian tissues or cultured cells by GC/MS. We demonstrate the relevance of this experimental approach by assessing the effects of drugs perturbing mitochondrial functions on the mass isotopomer enrichment of metabolic intermediates. Furthermore, we investigate 13C and 12C enrichments in mitochondria isolated from cancer cells given the emerging role of metabolic alterations in supporting tumor growth. This original method will provide a very sensitive tool to perform metabolomics studies on isolated mitochondria.

  17. Polyamines and WOX genes in the recalcitrance to plant conversion ...

    African Journals Online (AJOL)

    Raul Valle

    2015-02-18

    Feb 18, 2015 ... apparent that the induction of the embryogenic pathway ... 1.5 atm for 15 min. Once the seeds .... vacuoles, mitochondria and chloroplasts (Slocum, 1991). Borrell et al. ..... Shoot architecture in higher plants is highly dependent.

  18. 硝基芳香化合物的植物作用研究进展%Research progress in nitro-aromatic compounds in plants

    Institute of Scientific and Technical Information of China (English)

    张有贤; 刘振龙; 田鹏伟

    2013-01-01

    Nitro-aromatic compounds is one of the difficult biodegradable pollutants in the environment, due to its wide range of uses, large amounts of residues in the soil, water and atmosphere, caused increasingly serious environmental pollution. The pollutants can be absorbed or accumulated by various plants, as well as a metabolic degradation, using the vegetation to control its environmental pollution is an effective method. This paper reviewed recent studies nitro-aromatic compounds in plants, the uptake, transport and metabolism progress by plant are described, and the uptake and metabolism mechanism as well as effects of absorption;Nitro-arom-atic compounds physical and chemical properties, concentration and plant characteristics, in addition to other external conditions will affect the absorption of the plant, the plants decompose these compounds through the degradation of plants, joint metabolism in vitro, enzyme catalysis mechanism release by roots. Most of researches regarding the mechanism of nitro-aromatic compounds into the plant cell membrane are lack of in-depth understanding while the application of simulation model is lack of strong data for validation;environmental characteristics of enzymes and compounds involved in the reaction system mechanisms is still not clear, otherwise the reaction products, the feasibility of phytoremediation is lack of strong evidence too. In the future, we will make a further explore in the construction of model predictions, the depth of degradation mechanism research and practical application of the restoration project, forming a unified cognition, which will provide a theoretical basis for nitro-aromatic compounds contaminated soil and agricultural ecological risk assessment, and the phytoremediation.%  硝基芳香化合物是环境中难以降解的污染物之一。因其用途广泛,大量残留于土壤,水体和大气中,造成的环境污染日趋严重。多种植物对该类污染物具

  19. Beet yellow stunt virus in cells of Sonchus oleraceus L. and its relation to host mitochondria.

    Science.gov (United States)

    Esau, K

    1979-10-15

    In Sonchus oleraceus L. (Asteraceae) infected with the beet yellow stunt virus (BYSV) the virions are found in phloem cells, including the sieve elements. In parenchymatous phloem cells, the virus is present mainly in the cytoplasm. In some parenchymatous cells, containing massive accumulations of virus, the flexuous rodlike virus particles are found partly inserted into mitochondrial cristae. The mitochondrial envelope is absent where virus is present in the cristae. A similar relation between virus and host mitochondria apparently has not been recorded for any other plant virus.

  20. Mitochondria-endoplasmic reticulum choreography: structure and signaling dynamics.

    Science.gov (United States)

    Pizzo, Paola; Pozzan, Tullio

    2007-10-01

    Mitochondria and endoplasmic reticulum (ER) have different roles in living cells but they interact both physically and functionally. A key aspect of the mitochondria-ER relationship is the modulation of Ca(2+) signaling during cell activation, which thus affects a variety of physiological processes. We focus here on the molecular aspects that control the dynamics of the organelle-organelle interaction and their relationship with Ca(2+) signals, also discussing the consequences that these phenomena have, not only for cell physiology but also in the control of cell death.

  1. Mature Erythrocytes of Iguana iguana (Squamata, Iguanidae Possess Functional Mitochondria.

    Directory of Open Access Journals (Sweden)

    Giuseppina Di Giacomo

    Full Text Available Electron microscopy analyses of Iguana iguana blood preparations revealed the presence of mitochondria within erythrocytes with well-structured cristae. Fluorescence microscopy analyses upon incubation with phalloidin-FITC, Hoechst 33342 and mitochondrial transmembrane potential (Δψm-sensitive probe MitoTracker Red indicated that mitochondria i widely occur in erythrocytes, ii are polarized, and iii seem to be preferentially confined at a "perinuclear" region, as confirmed by electron microscopy. The analysis of NADH-dependent oxygen consumption showed that red blood cells retain the capability to consume oxygen, thereby providing compelling evidence that mitochondria of Iguana erythrocytes are functional and capable to perform oxidative phosphorylation.

  2. GENE TRANSFER IN TOBACCO MITOCHONDRIA IN VITRO AND IN VIVO

    Directory of Open Access Journals (Sweden)

    Katyshev A.I.

    2012-08-01

    Full Text Available Earlier, we had showed that isolated mitochondria from different organisms can import DNA. Exploiting this mechanism, we assessed the possibility of genes transfer in tobacco mitochondria in vitro and in vivo. Whereas homologous recombination is a rare occasion in higher plant nuclei, recombination between the large direct repeats in plant mitochondrial genome generates its multipartite structure. Following transfection of isolated organelles with constructs composed of a partial gfp gene flanked by mitochondrial DNA fragments, we showed the homologous recombination of imported DNA with the resident DNA and the integration of the reporter gene. The recombination yielded an insertion of a continuous exogenous DNA fragment including the gfp sequence and at least the 0.5 kb of the flanking sequence on each side. Using of transfection constructs carrying multiple sequences homologous to mitochondrial DNA could be suitable for insertion of a target gene into any region of the mitochondrial genome, which turns this approach to be of a general and methodical importance. Usually mitochondrial reactive oxygen species (ROS level is under strict control of the antioxidant system including the Mn-containing superoxide dismutase (MnSOD. MnSOD is presented in multiple forms encoded by several genes in plants. Possibly, this enzyme, beside its catalytic function, fulfills as well some unknown biochemical functions. Thus, one of maize SOD enzymes (SOD3.4 could bind with mitochondrial DNA. Another SOD form (SOD3.1 is located in close proximity to mitochondrial respiratory complexes, where ROS are generated. To study possible physiological functions of this enzyme, we cloned the maize SOD3.1 gene. Compared to the SOD3.4, this enzyme didn't demonstrate DNA-binding activity. At the same time, SOD3.1 didn't show non-specific DNA-hydrolyzing activity as Cu/ZnSOD does. It means that this enzyme might have some DNA protective function. We made NtPcob-sod3.1-IGR

  3. The Role of Mitochondria in the Activation/Maintenance of SOCE: Store-Operated Ca(2+) Entry and Mitochondria.

    Science.gov (United States)

    Spät, András; Szanda, Gergö

    2017-01-01

    Mitochondria extensively modify virtually all cellular Ca(2+) transport processes, and store-operated Ca(2+) entry (SOCE) is no exception to this rule. The interaction between SOCE and mitochondria is complex and reciprocal, substantially altering and, ultimately, fine-tuning both capacitative Ca(2+) influx and mitochondrial function. Mitochondria, owing to their considerable Ca(2+) accumulation ability, extensively buffer the cytosolic Ca(2+) in their vicinity. In turn, the accumulated ion is released back into the neighboring cytosol during net Ca(2+) efflux. Since store depletion itself and the successive SOCE are both Ca(2+)-regulated phenomena, mitochondrial Ca(2+) handling may have wide-ranging effects on capacitative Ca(2+) influx at any given time. In addition, mitochondria may also produce or consume soluble factors known to affect store-operated channels. On the other hand, Ca(2+) entering the cell during SOCE is sensed by mitochondria, and the ensuing mitochondrial Ca(2+) uptake boosts mitochondrial energy metabolism and, if Ca(2+) overload occurs, may even lead to apoptosis or cell death. In several cell types, mitochondria seem to be sterically excluded from the confined space that forms between the plasma membrane (PM) and endoplasmic reticulum (ER) during SOCE. This implies that high-Ca(2+) microdomains comparable to those observed between the ER and mitochondria do not form here. In the following chapter, the above aspects of the many-sided SOCE-mitochondrion interplay will be discussed in greater detail.

  4. The Rice Dynamin-Related Protein OsDRP1E Negatively Regulates Programmed Cell Death by Controlling the Release of Cytochrome c from Mitochondria

    Science.gov (United States)

    Zhou, Xueping

    2017-01-01

    Programmed cell death (PCD) mediated by mitochondrial processes has emerged as an important mechanism for plant development and responses to abiotic and biotic stresses. However, the role of translocation of cytochrome c from the mitochondria to the cytosol during PCD remains unclear. Here, we demonstrate that the rice dynamin-related protein 1E (OsDRP1E) negatively regulates PCD by controlling mitochondrial structure and cytochrome c release. We used a map-based cloning strategy to isolate OsDRP1E from the lesion mimic mutant dj-lm and confirmed that the E409V mutation in OsDRP1E causes spontaneous cell death in rice. Pathogen inoculation showed that dj-lm significantly enhances resistance to fungal and bacterial pathogens. Functional analysis of the E409V mutation showed that the mutant protein impairs OsDRP1E self-association and formation of a higher-order complex; this in turn reduces the GTPase activity of OsDRP1E. Furthermore, confocal microscopy showed that the E409V mutation impairs localization of OsDRP1E to the mitochondria. The E409V mutation significantly affects the morphogenesis of cristae in mitochondria and causes the abnormal release of cytochrome c from mitochondria into cytoplasm. Taken together, our results demonstrate that the mitochondria-localized protein OsDRP1E functions as a negative regulator of cytochrome c release and PCD in plants. PMID:28081268

  5. What do we know more than 2012 on the accident progression in Fukushima? What is the actual state of the plant?; Was wissen wir heute mehr als 2012 ueber den Unfallablauf in Fukushima? Wie ist der heutige Zustand der Anlage?

    Energy Technology Data Exchange (ETDEWEB)

    Maqua, Michael [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Koeln (Germany)

    2015-06-01

    The contribution includes the official statistics on the accident following the earthquake and tsunami on March 11, 2011 on the Japanese island Honshu and the nuclear power plant Fukushima Daiichi. The plant was automatically shutdown as consequence of the earthquake. New calculations allow the reconstruction of the accident progress and the meltdown. Estimations of the released radioactivity, esp. the radionuclides I-131 and Cs-137 into the atmosphere and the ocean are summarized. The construction of water cleaning facilities for the contaminated waste water in the leaking tanks, water-tight barriers and the planning for the enclosure for the destroyed reactor buildings are described.

  6. Changes in Plastid and Mitochondria Protein Expression in Arabidopsis Thaliana Callus on Board Chinese Spacecraft SZ-8

    Science.gov (United States)

    Zhang, Yue; Zheng, Hui Qiong

    2015-11-01

    Microgravity represents an adverse abiotic environment, which causes rearrangements in cellular organelles and changes in the energy metabolism of cells. Plastids and mitochondria are two subcellular energy organelles that are responsible for major metabolic processes, including photosynthesis, oxidative phosphorylation, ß-oxidation, and the tricarboxylic acid cycle. In our previous study performed on board the Chinese spacecraft SZ-8, we evaluated the global changes exerted by microgravity on the proteome of Arabidopsis thaliana cell cultures by comparing the microgravity-exposed samples with the controls either under 1 g centrifugation in space or 1 g ground conditions. Here, we report additional data from this space experiment that highlights the plastid and mitochondria proteins that responded to space flight conditions. We observed that 43 plastidial proteins and 50 mitochondrial proteins changed their abundances under microgravity in space. The major changes in both plastids and mitochondria involved proteins that functions in a suite of redox antioxidant and metabolic pathways. These results suggested that these antioxidant and metabolic changes in plastids and mitochondria could be important components of the adaptive strategy in plants subjected to microgravity in space.

  7. Mitochondria: An intriguing target for killing tumour-initiating cells.

    Science.gov (United States)

    Yan, Bing; Dong, Lanfeng; Neuzil, Jiri

    2016-01-01

    Tumour-initiating cells (TICs) play a pivotal role in cancer initiation, metastasis and recurrence, as well as in resistance to therapy. Therefore, development of drugs targeting TICs has become a focus of contemporary research. Mitochondria have emerged as a promising target of anti-cancer therapies due to their specific role in cancer metabolism and modulation of apoptotic pathways. Mitochondria of TICs possess special characteristics, some of which can be utilised to design drugs specifically targeting these cells. In this paper, we will review recent research on TICs and their mitochondria, and introduce drugs that kill these cells by way of mitochondrial targeting. Copyright © 2015 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

  8. Mitochondrial aging and age-related dysfunction of mitochondria.

    Science.gov (United States)

    Chistiakov, Dimitry A; Sobenin, Igor A; Revin, Victor V; Orekhov, Alexander N; Bobryshev, Yuri V

    2014-01-01

    Age-related changes in mitochondria are associated with decline in mitochondrial function. With advanced age, mitochondrial DNA volume, integrity and functionality decrease due to accumulation of mutations and oxidative damage induced by reactive oxygen species (ROS). In aged subjects, mitochondria are characterized by impaired function such as lowered oxidative capacity, reduced oxidative phosphorylation, decreased ATP production, significant increase in ROS generation, and diminished antioxidant defense. Mitochondrial biogenesis declines with age due to alterations in mitochondrial dynamics and inhibition of mitophagy, an autophagy process that removes dysfunctional mitochondria. Age-dependent abnormalities in mitochondrial quality control further weaken and impair mitochondrial function. In aged tissues, enhanced mitochondria-mediated apoptosis contributes to an increase in the percentage of apoptotic cells. However, implementation of strategies such as caloric restriction and regular physical training may delay mitochondrial aging and attenuate the age-related phenotype in humans.

  9. Mitochondria as Pharmacological Targets: The Discovery of Novel ...

    African Journals Online (AJOL)

    Obesity results from prolonged positive imbalance between energy in take and expenditure. When food intake chronically exceeds the body's energy need, an efficient metabolism results in the storage of the excess energy as fat. Mitochondria ...

  10. Enhanced oxidative capacity of ground squirrel brain mitochondria during hibernation.

    Science.gov (United States)

    Ballinger, Mallory A; Schwartz, Christine; Andrews, Matthew T

    2017-03-01

    During hibernation, thirteen-lined ground squirrels (Ictidomys tridecemlineatus) regularly cycle between bouts of torpor and interbout arousal (IBA). Most of the brain is electrically quiescent during torpor but regains activity quickly upon arousal to IBA, resulting in extreme oscillations in energy demand during hibernation. We predicted increased functional capacity of brain mitochondria during hibernation compared with spring to accommodate the variable energy demands of hibernation. To address this hypothesis, we examined mitochondrial bioenergetics in the ground squirrel brain across three time points: spring (SP), torpor (TOR), and IBA. Respiration rates of isolated brain mitochondria through complex I of the electron transport chain were more than twofold higher in TOR and IBA than in SP (P mitochondria compared with TOR and IBA (P mitochondria function more effectively during the hibernation season, allowing for rapid production of energy to meet demand when extreme physiological changes are occurring. Copyright © 2017 the American Physiological Society.

  11. Lipid Transport between the Endoplasmic Reticulum and Mitochondria

    Science.gov (United States)

    Flis, Vid V.

    2013-01-01

    Mitochondria are partially autonomous organelles that depend on the import of certain proteins and lipids to maintain cell survival and membrane formation. Although phosphatidylglycerol, cardiolipin, and phosphatidylethanolamine are synthesized by mitochondrial enzymes, phosphatidylcholine, phosphatidylinositol, phosphatidylserine, and sterols need to be imported from other organelles. The origin of most lipids imported into mitochondria is the endoplasmic reticulum, which requires interaction of these two subcellular compartments. Recently, protein complexes that are involved in membrane contact between endoplasmic reticulum and mitochondria were identified, but their role in lipid transport is still unclear. In the present review, we describe components involved in lipid translocation between the endoplasmic reticulum and mitochondria and discuss functional as well as regulatory aspects that are important for lipid homeostasis. PMID:23732475

  12. Parkinson's Disease: The Mitochondria-Iron Link.

    Science.gov (United States)

    Muñoz, Yorka; Carrasco, Carlos M; Campos, Joaquín D; Aguirre, Pabla; Núñez, Marco T

    2016-01-01

    Mitochondrial dysfunction, iron accumulation, and oxidative damage are conditions often found in damaged brain areas of Parkinson's disease. We propose that a causal link exists between these three events. Mitochondrial dysfunction results not only in increased reactive oxygen species production but also in decreased iron-sulfur cluster synthesis and unorthodox activation of Iron Regulatory Protein 1 (IRP1), a key regulator of cell iron homeostasis. In turn, IRP1 activation results in iron accumulation and hydroxyl radical-mediated damage. These three occurrences-mitochondrial dysfunction, iron accumulation, and oxidative damage-generate a positive feedback loop of increased iron accumulation and oxidative stress. Here, we review the evidence that points to a link between mitochondrial dysfunction and iron accumulation as early events in the development of sporadic and genetic cases of Parkinson's disease. Finally, an attempt is done to contextualize the possible relationship between mitochondria dysfunction and iron dyshomeostasis. Based on published evidence, we propose that iron chelation-by decreasing iron-associated oxidative damage and by inducing cell survival and cell-rescue pathways-is a viable therapy for retarding this cycle.

  13. Giant crystals inside mitochondria of equine chondrocytes.

    Science.gov (United States)

    Nürnberger, S; Rentenberger, C; Thiel, K; Schädl, B; Grunwald, I; Ponomarev, I; Marlovits, St; Meyer, Ch; Barnewitz, D

    2017-05-01

    The present study reports for the first time the presence of giant crystals in mitochondria of equine chondrocytes. These structures show dark contrast in TEM images as well as a granular substructure of regularly aligned 1-2 nm small units. Different zone axes of the crystalline structure were analysed by means of Fourier transformation of lattice-resolution TEM images proving the crystalline nature of the structure. Elemental analysis reveals a high content of nitrogen referring to protein. The outer shape of the crystals is geometrical with an up to hexagonal profile in cross sections. It is elongated, spanning a length of several micrometres through the whole cell. In some chondrocytes, several crystals were found, sometimes combined in a single mitochondrion. Crystals were preferentially aligned along the long axis of the cells, thus appearing in the same orientation as the chondrocytes in the tissue. Although no similar structures have been found in the cartilage of any other species investigated, they have been found in cartilage repair tissue formed within a mechanically stimulated equine chondrocyte construct. Crystals were mainly located in superficial regions of cartilage, especially in joint regions of well-developed superficial layers, more often in yearlings than in adult horses. These results indicate that intramitochondrial crystals are related to the high mechanical stress in the horse joint and potentially also to the increased metabolic activity of immature individuals.

  14. Biogenesis and dynamics of mitochondria during the cell cycle: significance of 3'UTRs.

    Directory of Open Access Journals (Sweden)

    Marta Martínez-Diez

    Full Text Available Nowadays, we are facing a renaissance of mitochondria in cancer biology. However, our knowledge of the basic cell biology and on the timing and mechanisms that control the biosynthesis of mitochondrial constituents during progression through the cell cycle of mammalian cells remain largely unknown. Herein, we document the in vivo changes on mitochondrial morphology and dynamics that accompany cellular mitosis, and illustrate the following key points of the biogenesis of mitochondria during progression of liver cells through the cycle: (i the replication of nuclear and mitochondrial genomes is synchronized during cellular proliferation, (ii the accretion of OXPHOS proteins is asynchronously regulated during proliferation being the synthesis of beta-F1-ATPase and Hsp60 carried out also at G2/M and, (iii the biosynthesis of cardiolipin is achieved during the S phase, although full development of the mitochondrial membrane potential (DeltaPsim is attained at G2/M. Furthermore, we demonstrate using reporter constructs that the mechanism regulating the accretion of beta-F1-ATPase during cellular proliferation is controlled at the level of mRNA translation by the 3'UTR of the transcript. The 3'UTR-driven synthesis of the protein at G2/M is essential for conferring to the daughter cells the original phenotype of the parental cell. Our findings suggest that alterations on this process may promote deregulated beta-F1-ATPase expression in human cancer.

  15. A common evolutionary origin for mitochondria and hydrogenosomes.

    OpenAIRE

    Bui, E T; Bradley, P J; Johnson, P J

    1996-01-01

    Trichomonads are among the earliest eukaryotes to diverge from the main line of eukaryotic descent. Keeping with their ancient nature, these facultative anaerobic protists lack two "hallmark" organelles found in most eukaryotes: mitochondria and peroxisomes. Trichomonads do, however, contain an unusual organelle involved in carbohydrate metabolism called the hydrogenosome. Like mitochondria, hydrogenosomes are double-membrane bounded organelles that produce ATP using pyruvate as the primary s...

  16. Mitochondria Maintain Distinct Ca(2+) Pools in Cone Photoreceptors.

    Science.gov (United States)

    Giarmarco, Michelle M; Cleghorn, Whitney M; Sloat, Stephanie R; Hurley, James B; Brockerhoff, Susan E

    2017-02-22

    Ca(2+) ions have distinct roles in the outer segment, cell body, and synaptic terminal of photoreceptors. We tested the hypothesis that distinct Ca(2+) domains are maintained by Ca(2+) uptake into mitochondria. Serial block face scanning electron microscopy of zebrafish cones revealed that nearly 100 mitochondria cluster at the apical side of the inner segment, directly below the outer segment. The endoplasmic reticulum surrounds the basal and lateral surfaces of this cluster, but does not reach the apical surface or penetrate into the cluster. Using genetically encoded Ca(2+) sensors, we found that mitochondria take up Ca(2+) when it accumulates either in the cone cell body or outer segment. Blocking mitochondrial Ca(2+) uniporter activity compromises the ability of mitochondria to maintain distinct Ca(2+) domains. Together, our findings indicate that mitochondria can modulate subcellular functional specialization in photoreceptors.SIGNIFICANCE STATEMENT Ca(2+) homeostasis is essential for the survival and function of retinal photoreceptors. Separate pools of Ca(2+) regulate phototransduction in the outer segment, metabolism in the cell body, and neurotransmitter release at the synaptic terminal. We investigated the role of mitochondria in compartmentalization of Ca(2+) We found that mitochondria form a dense cluster that acts as a diffusion barrier between the outer segment and cell body. The cluster is surprisingly only partially surrounded by the endoplasmic reticulum, a key mediator of mitochondrial Ca(2+) uptake. Blocking the uptake of Ca(2+) by mitochondria causes redistribution of Ca(2+) throughout the cell. Our results show that mitochondrial Ca(2+) uptake in photoreceptors is complex and plays an essential role in normal function. Copyright © 2017 the authors 0270-6474/17/372061-12$15.00/0.

  17. Sequence evidence for the symbiotic origins of chloroplasts and mitochondria

    Science.gov (United States)

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

    1983-01-01

    The origin of mitochondria and chloroplasts is investigated on the basis of prokaryotic and early-eukaryotic evolutionary trees derived from protein and nucleic-acid sequences by the method of Dayhoff (1979). Trees for bacterial ferrodoxins, 5S ribosomal RNA, c-type cytochromes, the lipid-binding subunit of ATPase, and dihydrofolate reductase are presented and discussed. Good agreement among the trees is found, and it is argued that the mitochondria and chloroplasts evolved by multiple symbiotic events.

  18. Depletion of mitochondria in mammalian cells through enforced mitophagy.

    Science.gov (United States)

    Correia-Melo, Clara; Ichim, Gabriel; Tait, Stephen W G; Passos, João F

    2017-01-01

    Mitochondria are not only the 'powerhouse' of the cell; they are also involved in a multitude of processes that include calcium storage, the cell cycle and cell death. Traditional means of investigating mitochondrial importance in a given cellular process have centered upon depletion of mtDNA through chemical or genetic means. Although these methods severely disrupt the mitochondrial electron transport chain, mtDNA-depleted cells still maintain mitochondria and many mitochondrial functions. Here we describe a straightforward protocol to generate mammalian cell populations with low to nondetectable levels of mitochondria. Ectopic expression of the ubiquitin E3 ligase Parkin, combined with short-term mitochondrial uncoupler treatment, stimulates widespread mitophagy and effectively eliminates mitochondria. In this protocol, we explain how to generate Parkin-expressing, mitochondria-depleted cells from scratch in 23 d, as well as offer a variety of methods for confirming mitochondrial clearance. Furthermore, we describe culture conditions to maintain mitochondrial-depleted cells for up to 30 d with minimal loss of viability, for longitudinal studies. This method should prove useful for investigating the importance of mitochondria in a variety of biological processes.

  19. Internalization of isolated functional mitochondria: involvement of macropinocytosis

    Science.gov (United States)

    Kitani, Tomoya; Kami, Daisuke; Matoba, Satoaki; Gojo, Satoshi

    2014-01-01

    In eukaryotic cells, mitochondrial dysfunction is associated with a variety of human diseases. Delivery of exogenous functional mitochondria into damaged cells has been proposed as a mechanism of cell transplant and physiological repair for damaged tissue. We here demonstrated that isolated mitochondria can be transferred into homogeneic and xenogeneic cells by simple co-incubation using genetically labelled mitochondria, and elucidated the mechanism and the effect of direct mitochondrial transfer. Intracellular localization of exogenous mitochondria was confirmed by PCR, real-time PCR, live fluorescence imaging, three-dimensional reconstruction imaging, continuous time-lapse microscopic observation, flow cytometric analysis and immunoelectron microscopy. Isolated homogeneic mitochondria were transferred into human uterine endometrial gland-derived mesenchymal cells in a dose-dependent manner. Moreover, mitochondrial transfer rescued the mitochondrial respiratory function and improved the cellular viability in mitochondrial DNA-depleted cells and these effects lasted several days. Finally, we discovered that mitochondrial internalization involves macropinocytosis. In conclusion, these data support direct transfer of exogenous mitochondria as a promising approach for the treatment of various diseases. PMID:24912369

  20. Cytosolic proteostasis through importing of misfolded proteins into mitochondria.

    Science.gov (United States)

    Ruan, Linhao; Zhou, Chuankai; Jin, Erli; Kucharavy, Andrei; Zhang, Ying; Wen, Zhihui; Florens, Laurence; Li, Rong

    2017-03-16

    Loss of proteostasis underlies ageing and neurodegeneration characterized by the accumulation of protein aggregates and mitochondrial dysfunction. Although many neurodegenerative-disease-associated proteins can be found in mitochondria, it remains unclear how mitochondrial dysfunction and protein aggregation could be related. In dividing yeast cells, protein aggregates that form under stress or during ageing are preferentially retained by the mother cell, in part through tethering to mitochondria, while the disaggregase Hsp104 helps to dissociate aggregates and thereby enables refolding or degradation of misfolded proteins. Here we show that, in yeast, cytosolic proteins prone to aggregation are imported into mitochondria for degradation. Protein aggregates that form under heat shock contain both cytosolic and mitochondrial proteins and interact with the mitochondrial import complex. Many aggregation-prone proteins enter the mitochondrial intermembrane space and matrix after heat shock, and some do so even without stress. Timely dissolution of cytosolic aggregates requires the mitochondrial import machinery and proteases. Blocking mitochondrial import but not proteasome activity causes a marked delay in the degradation of aggregated proteins. Defects in cytosolic Hsp70s leads to enhanced entry of misfolded proteins into mitochondria and elevated mitochondrial stress. We term this mitochondria-mediated proteostasis mechanism MAGIC (mitochondria as guardian in cytosol) and provide evidence that it may exist in human cells.

  1. Mitochondria and endoplasmic reticulum crosstalk in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Manfredi, Giovanni; Kawamata, Hibiki

    2016-06-01

    Physical and functional interactions between mitochondria and the endoplasmic reticulum (ER) are crucial for cell life. These two organelles are intimately connected and collaborate to essential processes, such as calcium homeostasis and phospholipid biosynthesis. The connections between mitochondria and endoplasmic reticulum occur through structures named mitochondria associated membranes (MAMs), which contain lipid rafts and a large number of proteins, many of which serve multiple functions at different cellular sites. Growing evidence strongly suggests that alterations of ER-mitochondria interactions are involved in neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS), a devastating and rapidly fatal motor neuron disease. Mutations in proteins that participate in ER-mitochondria interactions and MAM functions are increasingly being associated with genetic forms of ALS and other neurodegenerative diseases. This evidence strongly suggests that, rather than considering the two organelles separately, a better understanding of the disease process can derive from studying the alterations in their crosstalk. In this review we discuss normal and pathological ER-mitochondria interactions and the evidence that link them to ALS. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Mitochondria-targeted Antioxidants as a Prospective Therapeutic Strategy for Multiple Sclerosis.

    Science.gov (United States)

    Fetisova, Elena; Chernyak, Boris; Korshunova, Galina; Muntyan, Maria; Skulachev, Vladimir

    2017-01-01

    Multiple sclerosis (MS) is one of the most widespread chronic neurological diseases that manifests itself by progressive demyelination in the central nervous system. The study of MS pathogenesis begins with the onset of the relapsing-remitting phase of the disease, which becomes apparent due to microglia activation, neuroinflammation and demyelination/ remyelination in the white matter. The following progressive phase is accompanied by severe neurological symptoms when demyelination and neurodegeneration are spread to both gray and white matter. In this review, we discuss a possible role of mitochondrial reactive oxygen species (mtROS) in MS pathogenesis, mechanisms of mtROS generation and effects of some mitochondria-targeted antioxidants as potential components of MS therapy. In the early phase of MS, mtROS stimulate NLRP3 inflammasomes, which is critical for the formation of local inflammatory lesions. Later, mtROS contribute to blood-brain barrier disruption induced by mediators of inflammation, followed by infiltration of leukocytes. ROS generated by leukocytes and activated microglia promote mitochondrial dysfunction and oligodendrocyte cell death. In the progressive phase, neurodegeneration also depends on excessive mtROS generation. Currently, only a few immunomodulatory drugs are approved for treatment of MS. These drugs mainly reduce the number of relapses but do not stop MS progression. Certain dietary and synthetic antioxidants have demonstrated encouraging results in animal models of MS but were ineffective in the completed clinical trials. Novel mitochondria-targeted antioxidants could be promising components of combined programs for MS therapy considering that they can be applied at extremely low doses and concurrently demonstrate anti-inflammatory and neuroprotective activities. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. 2012 Gordon Research Conference, Mitochondria and Chloroplasts, July 29 - Aug 3 2012

    Energy Technology Data Exchange (ETDEWEB)

    Barkan, Alice [Univ. of Oregon, Eugene, OR (United States)

    2012-08-03

    The 2012 Gordon Research Conference on Mitochondria and Chloroplasts will assemble an international group of scientists investigating fundamental properties of these organelles, and their integration into broader physiological processes. The conference will emphasize the many commonalities between mitochondria and chloroplasts: their evolution from bacterial endosymbionts, their genomes and gene expression systems, their energy transducing membranes whose proteins derive from both nuclear and organellar genes, the challenge of maintaining organelle integrity in the presence of the reactive oxygen species that are generated during energy transduction, their incorporation into organismal signaling pathways, and more. The conference will bring together investigators working in animal, plant, fungal and protozoan systems who specialize in cell biology, genetics, biochemistry, physiology, proteomics, genomics, and structural biology. As such, this conference will provide a unique forum that engenders cross-disciplinary discussions concerning the biogenesis, dynamics, and regulation of these key cellular structures. By fostering interactions among mammalian, fungal and plant organellar biologists, this conference also provides a conduit for the transmission of mechanistic insights obtained in model organisms to applications in medicine and agriculture. The 2012 conference will highlight areas that are moving rapidly and emerging themes. These include new insights into the ultrastructure and organization of the energy transducing membranes, the coupling of organellar gene expression with the assembly of photosynthetic and respiratory complexes, the regulatory networks that couple organelle biogenesis with developmental and physiological signals, the signaling events through which organellar physiology influences nuclear gene expression, and the roles of organelles in disease and development.

  4. Mitochondria and Mitochondrial ROS in Cancer: Novel Targets for Anticancer Therapy.

    Science.gov (United States)

    Yang, Yuhui; Karakhanova, Svetlana; Hartwig, Werner; D'Haese, Jan G; Philippov, Pavel P; Werner, Jens; Bazhin, Alexandr V

    2016-12-01

    Mitochondria are indispensable for energy metabolism, apoptosis regulation, and cell signaling. Mitochondria in malignant cells differ structurally and functionally from those in normal cells and participate actively in metabolic reprogramming. Mitochondria in cancer cells are characterized by reactive oxygen species (ROS) overproduction, which promotes cancer development by inducing genomic instability, modifying gene expression, and participating in signaling pathways. Mitochondrial and nuclear DNA mutations caused by oxidative damage that impair the oxidative phosphorylation process will result in further mitochondrial ROS production, completing the "vicious cycle" between mitochondria, ROS, genomic instability, and cancer development. The multiple essential roles of mitochondria have been utilized for designing novel mitochondria-targeted anticancer agents. Selective drug delivery to mitochondria helps to increase specificity and reduce toxicity of these agents. In order to reduce mitochondrial ROS production, mitochondria-targeted antioxidants can specifically accumulate in mitochondria by affiliating to a lipophilic penetrating cation and prevent mitochondria from oxidative damage. In consistence with the oncogenic role of ROS, mitochondria-targeted antioxidants are found to be effective in cancer prevention and anticancer therapy. A better understanding of the role played by mitochondria in cancer development will help to reveal more therapeutic targets, and will help to increase the activity and selectivity of mitochondria-targeted anticancer drugs. In this review we summarized the impact of mitochondria on cancer and gave summary about the possibilities to target mitochondria for anticancer therapies. J. Cell. Physiol. 231: 2570-2581, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Fis1 and Bap31 bridge the mitochondria-ER interface to establish a platform for apoptosis induction.

    Science.gov (United States)

    Iwasawa, Ryota; Mahul-Mellier, Anne-Laure; Datler, Christoph; Pazarentzos, Evangelos; Grimm, Stefan

    2011-02-02

    The mitochondria and the endoplasmic reticulum (ER) are two organelles that critically contribute to apoptosis induction. While it is established that they communicate, how cell death signals are transmitted from the mitochondria to the ER is unknown. Here, we show that the mitochondrial fission protein Fission 1 homologue (Fis1) conveys an apoptosis signal from the mitochondria to the ER by interacting with Bap31 at the ER and facilitating its cleavage into the pro-apoptotic p20Bap31. Exogenous apoptosis inducers likewise use this signalling route and induce the procession of Bap31. Moreover, we show that the recruitment of procaspase-8 to the Fis1-Bap31 platform is an early event during apoptosis induction. The association of procaspase-8 with the Fis1-Bap31 complex is dependent on the variant of death effector domain (vDED) in Bap31 and is required for the activation of procaspase-8. This signalling pathway establishes a feedback loop by releasing Ca(2+) from the ER that activates the mitochondria for apoptosis. Hence, the Fis1-Bap31 complex (ARCosome) that spans the mitochondria-ER interface serves as a platform to activate the initiator procaspase-8, and thereby bridges two critical organelles for apoptosis signalling.

  6. Incidence of ripening and chilling injury on the oxidative activities and Fatty Acid compositions of the mitochondria from mango fruits.

    Science.gov (United States)

    Kane, O; Marcellin, P

    1978-04-01

    The succinate oxidation capacities of mitochondria isolated from mango fruits (Mangifera indica L.) stored at 4, 8, 12, and 20 C were investigated during storage. In normally ripening fruits (at 12 and 20 C) the oxidative capacities increased during the first 10 days and then decreased slowly. At lower temperatures (4 and 8 C), the fruits showed chilling injury symptoms, after about 10 days of storage and the succinate oxidation capacities of mitochondria decreased progressively. Plots of succinate oxidation capacities as against storage temperature showed a marked discontinuity between 12 and 8 C, only when chilling injury was observed on fruits stored at low temperature.The variations of mitochondrial fatty acid composition during the storage of fruits at different temperatures were also investigated. A marked decrease of the molar ratio palmitoleic acid/palmitic acid, the predominant fatty acids in mitochondrial lipids, was observed to accompany both the succinate oxidation decrease and the induction of chilling injury.

  7. Intracellular position of mitochondria and chloroplasts in bundle sheath and mesophyll cells of C3 grasses in relation to photorespiratory CO2 loss

    Directory of Open Access Journals (Sweden)

    Yuto Hatakeyama

    2016-10-01

    Full Text Available In C3 plants, photosynthetic efficiency is reduced by photorespiration. A part of CO2 fixed during photosynthesis in chloroplasts is lost from mitochondria during photorespiration by decarboxylation of glycine by glycine decarboxylase (GDC. Thus, the intracellular position of mitochondria in photosynthetic cells is critical to the rate of photorespiratory CO2 loss. We investigated the intracellular position of mitochondria in parenchyma sheath (PS and mesophyll cells of 10 C3 grasses from 3 subfamilies (Ehrhartoideae, Panicoideae, and Pooideae by immunostaining for GDC and light and electron microscopic observation. Immunostaining suggested that many mitochondria were located in the inner half of PS cells and on the vacuole side of chloroplasts in mesophyll cells. Organelle quantification showed that 62–75% of PS mitochondria were located in the inner half of cells, and 62–78% of PS chloroplasts were in the outer half. In mesophyll cells, 61–92% of mitochondria were positioned on the vacuole side of chloroplasts and stromules. In PS cells, such location would reduce the loss of photorespiratory CO2 by lengthening the path of CO2 diffusion and allow more efficient fixation of CO2 from intercellular spaces. In mesophyll cells, it would facilitate scavenging by chloroplasts of photorespiratory CO2 released from mitochondria. Our data suggest that the PS cells of C3 grasses have already acquired an initial structure leading to proto-Kranz and further C3–C4 intermediate anatomy. We also found that in the Pooideae, organelle positioning in PS cells on the phloem side resembles that in mesophyll cells.

  8. Calcium signaling in plant endosymbiotic organelles: mechanism and role in physiology.

    Science.gov (United States)

    Nomura, Hironari; Shiina, Takashi

    2014-07-01

    Recent studies have demonstrated that chloroplasts and mitochondria evoke specific Ca(2+) signals in response to biotic and abiotic stresses in a stress-dependent manner. The identification of Ca(2+) transporters and Ca(2+) signaling molecules in chloroplasts and mitochondria implies that they play roles in controlling not only intra-organellar functions, but also extra-organellar processes such as plant immunity and stress responses. It appears that organellar Ca(2+) signaling might be more important to plant cell functions than previously thought. This review briefly summarizes what is known about the molecular basis of Ca(2+) signaling in plant mitochondria and chloroplasts.

  9. Lack of FTSH4 Protease Affects Protein Carbonylation, Mitochondrial Morphology, and Phospholipid Content in Mitochondria of Arabidopsis: New Insights into a Complex Interplay.

    Science.gov (United States)

    Smakowska, Elwira; Skibior-Blaszczyk, Renata; Czarna, Malgorzata; Kolodziejczak, Marta; Kwasniak-Owczarek, Malgorzata; Parys, Katarzyna; Funk, Christiane; Janska, Hanna

    2016-08-01

    FTSH4 is one of the inner membrane-embedded ATP-dependent metalloproteases in mitochondria of Arabidopsis (Arabidopsis thaliana). In mutants impaired to express FTSH4, carbonylated proteins accumulated and leaf morphology was altered when grown under a short-day photoperiod, at 22°C, and a long-day photoperiod, at 30°C. To provide better insight into the function of FTSH4, we compared the mitochondrial proteomes and oxyproteomes of two ftsh4 mutants and wild-type plants grown under conditions inducing the phenotypic alterations. Numerous proteins from various submitochondrial compartments were observed to be carbonylated in the ftsh4 mutants, indicating a widespread oxidative stress. One of the reasons for the accumulation of carbonylated proteins in ftsh4 was the limited ATP-dependent proteolytic capacity of ftsh4 mitochondria, arising from insufficient ATP amount, probably as a result of an impaired oxidative phosphorylation (OXPHOS), especially complex V. In ftsh4, we further observed giant, spherical mitochondria coexisting among normal ones. Both effects, the increased number of abnormal mitochondria and the decreased stability/activity of the OXPHOS complexes, were probably caused by the lower amount of the mitochondrial membrane phospholipid cardiolipin. We postulate that the reduced cardiolipin content in ftsh4 mitochondria leads to perturbations within the OXPHOS complexes, generating more reactive oxygen species and less ATP, and to the deregulation of mitochondrial dynamics, causing in consequence the accumulation of oxidative damage.

  10. Synthetic mitochondria as therapeutics against systemic aging: a hypothesis.

    Science.gov (United States)

    Tang, Bor Luen

    2015-02-01

    We hypothesize herein that synthetic mitochondria, engineered, or reprogrammed to be more energetically efficient and to have mildly elevated levels of reactive oxygen species (ROS) production, would be an effective form of therapeutics against systemic aging. The free radical and mitochondria theories of aging hold that mitochondria-generated ROS underlies chronic organelle, cell and tissues damages that contribute to systemic aging. More recent findings, however, collectively suggest that while acute and massive ROS generation during events such as tissue injury is indeed detrimental, subacute stresses, and chronic elevation in ROS production may instead induce a state of mitochondrial hormesis (or "mitohormesis") that could extend lifespan. Mitohormesis appears to be a convergent mechanism for several known anti-aging signaling pathways. Importantly, mitohormetic signaling could also occur in a non-cell autonomous manner, with its induction in neurons affecting gut cells, for example. Technologies are outlined that could lead towards testing of the hypothesis, which include genetic and epigenetic engineering of the mitochondria, as well as intercellular transfer of mitochondria from transplanted helper cells to target tissues. © 2014 International Federation for Cell Biology.

  11. The cellular energy crisis: mitochondria and cell death.

    Science.gov (United States)

    Waterhouse, Nigel J

    2003-01-01

    Exploding nuclear reactors, environmental destruction, and global warming; the danger of energy production is clear. It is quite remarkable that in this modern age, where power usage is at a premium, we find that even on a cellular level, generation of large quantities of power comes at a cost. Mitochondria, which produce the majority of cellular energy in the form of ATP, have recently been shown to play an essential role in the death of a cell by a process known as apoptosis. During apoptosis, the integrity of mitochondria is compromised and various pro-apoptotic proteins are released into the cytoplasm. This results in activation of caspases, proteases that orchestrate the death of the cell. Cells in which apoptosis is inhibited upstream of mitochondria generally maintain the potential to proliferate, whereas inhibition of caspases downstream of mitochondria generally only delays cell death. Although breaches of the mitochondrial outer membrane result in the release of proteins that are important for respiration, mitochondria appear capable of maintaining at least some of their functions, including ATP production, even after this event. This has important implications both for the mechanism of outer-membrane permeabilization and the mechanism by which the cells eventually die in the absence of caspase activity. The events surrounding the breach of the mitochondrial outer membrane during apoptosis have therefore received much interest over the past few years.

  12. Effects of melatonin on mitochondria after cerebral isehemic reperfusion

    Institute of Scientific and Technical Information of China (English)

    Wang Hongyu

    2000-01-01

    Melatonin has been regarded as a free radical scavenger and antioxidant. In both in vitro and in vivo experiments. Melatonin was found to protect cells, tissues and organs against oxidative damage induced by a variety of free radical generating agents and processes, e.g., ischemic reperfusion. The mechanisms underlying these interactions have not been defined. The goal of the present study was to observe the effects of melatonin on rnitochondria after cerebral ischemic reperfusion and the mechanisms of neuroprotection of melatonin by gerbil ischemic model. Male Mongolian gerbils were subjected to 10 min of forebrain ischemia by occlusion of both common carotid arteries under anesthesia. Melatonin(0.8 mg/kg) was administrated intraperitoneum 30 min befbre arteries occlusion. We measured the respiratory function of mitochondria, the activities of ATPase, the free mitochondrial calcium contents and the GSH level of mitochondria. The results show that oxidative phosphorylation function of mitochondria was damaged after cerebral ischemic reperfusion. And mitochondrial calcium was overloaded after cerebral ischemic reperfusion. And the level of GSH in mitochondria decreased after cerebral ischemic reperfision. It is concluded that melatonin have neuroprotection effects after cerebral ischemic repertusion and this effects probably related to the protection mitochondria.

  13. Mitochondria Localize to Injured Axons to Support Regeneration.

    Science.gov (United States)

    Han, Sung Min; Baig, Huma S; Hammarlund, Marc

    2016-12-21

    Axon regeneration is essential to restore the nervous system after axon injury. However, the neuronal cell biology that underlies axon regeneration is incompletely understood. Here we use in vivo, single-neuron analysis to investigate the relationship between nerve injury, mitochondrial localization, and axon regeneration. Mitochondria translocate into injured axons so that average mitochondria density increases after injury. Moreover, single-neuron analysis reveals that axons that fail to increase mitochondria have poor regeneration. Experimental alterations to axonal mitochondrial distribution or mitochondrial respiratory chain function result in corresponding changes to regeneration outcomes. Axonal mitochondria are specifically required for growth-cone migration, identifying a key energy challenge for injured neurons. Finally, mitochondrial localization to the axon after injury is regulated in part by dual-leucine zipper kinase 1 (DLK-1), a conserved regulator of axon regeneration. These data identify regulation of axonal mitochondria as a new cell-biological mechanism that helps determine the regenerative response of injured neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Methods to Study PTEN in Mitochondria and Endoplasmic Reticulum.

    Science.gov (United States)

    Missiroli, Sonia; Morganti, Claudia; Giorgi, Carlotta; Pinton, Paolo

    2016-01-01

    Although PTEN has been widely described as a nuclear and cytosolic protein, in the last 2 years, alternative organelles, such as the endoplasmic reticulum (ER), pure mitochondria, and mitochondria-associated membranes (MAMs), have been recognized as pivotal targets of PTEN activity.Here, we describe different methods that have been used to highlight PTEN subcellular localization.First, a protocol to extract nuclear and cytosolic fractions has been described to assess the "canonical" PTEN localization. Moreover, we describe a protocol for mitochondria isolation with proteinase K (PK) to further discriminate whether PTEN associates with the outer mitochondrial membrane (OMM) or resides within the mitochondria. Finally, we focus our attention on a subcellular fractionation protocol of cells that permits the isolation of MAMs containing unique regions of ER membranes attached to the outer mitochondrial membrane (OMM) and mitochondria without contamination from other organelles. In addition to biochemical fractionations, immunostaining can be used to determine the subcellular localization of proteins; thus, a detailed protocol to obtain good immunofluorescence (IF) is described. The employment of these methodological approaches could facilitate the identification of different PTEN localizations in several physiopathological contexts.

  15. Endoplasmic reticulum-mitochondria calcium signaling in hepatic metabolic diseases.

    Science.gov (United States)

    Rieusset, Jennifer

    2017-06-01

    The liver plays a central role in glucose homeostasis, and both metabolic inflexibility and insulin resistance predispose to the development of hepatic metabolic diseases. Mitochondria and endoplasmic reticulum (ER), which play a key role in the control of hepatic metabolism, also interact at contact points defined as mitochondria-associated membranes (MAM), in order to exchange metabolites and calcium (Ca(2+)) and regulate cellular homeostasis and signaling. Here, we overview the role of the liver in the control of glucose homeostasis, mainly focusing on the independent involvement of mitochondria, ER and Ca(2+) signaling in both healthy and pathological contexts. Then we focus on recent data highlighting MAM as important hubs for hormone and nutrient signaling in the liver, thus adapting mitochondria physiology and cellular metabolism to energy availability. Lastly, we discuss how chronic ER-mitochondria miscommunication could participate to hepatic metabolic diseases, pointing MAM interface as a potential therapeutic target for metabolic disorders. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Proteomic approaches to the study of renal mitochondria.

    Science.gov (United States)

    Tuma, Zdenek; Kuncova, Jitka; Mares, Jan; Grundmanova, Martina; Matejovic, Martin

    2016-06-01

    Dysfunction of kidney mitochondria plays a critical role in the pathogenesis of a number of renal diseases. Proteomics represents an untargeted attempt to reveal the remodeling of mitochondrial proteins during disease. Combination of separation methods and mass spectrometry allows identification and quantitative analysis of mitochondrial proteins including protein complexes. The aim of this review is to summarize the methods and applications of proteomics to renal mitochondria. Using keywords "mitochondria", "kidney", "proteomics", scientific databases (PubMed and Web of knowledge) were searched from 2000 to August 2015 for articles describing methods and applications of proteomics to analysis of mitochondrial proteins in kidney. Included were publications on mitochondrial proteins in kidneys of humans and animal model in health and disease. Proteomics of renal mitochondria has been/is mostly used in diabetes, hypertension, acidosis, nephrotoxicity and renal cancer. Integration of proteomics with other methods for examining protein activity is promising for insight into the role of renal mitochondria in pathological states. Several challenges were identified: selection of appropriate model organism, sensitivity of analytical methods and analysis of mitochondrial proteome in different renal zones/biopsies in the course of various kidney disorders.

  17. Fluoxetine and the mitochondria: A review of the toxicological aspects.

    Science.gov (United States)

    de Oliveira, Marcos Roberto

    2016-09-06

    Fluoxetine (a selective serotonin reuptake inhibitor (SSRI)) is used as an antidepressant by modulating the levels of serotonin in the synaptic cleft. Nevertheless, fluoxetine also induces undesirable effects, such as anxiety, sexual dysfunction, sleep disturbances, and gastrointestinal impairments. Fluoxetine has been viewed as an agent that may interfere with cell fate by triggering apoptosis. On the other hand, fluoxetine intake has been associated with increased cancer risk. Nonetheless, data remain contradictory and no conclusions were taken. Several studies demonstrated that fluoxetine interacts with mitochondria triggering apoptosis and/or altering mitochondrial function by modulating the activity of respiratory chain components and enzymes of the Krebs cycle. Furthermore, fluoxetine affects mitochondria-related redox parameters in different experimental models. In this review, data demonstrating the effects of fluoxetine upon mammalian mitochondria are described and discussed, as well as several unsolved questions in this field of research are addressed. A separate section deals with future needs regarding the research involving the impact of fluoxetine treatment upon mitochondria and mitochondria-related signaling. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Mitochondria: 3-bromopyruvate vs. mitochondria? A small molecule that attacks tumors by targeting their bioenergetic diversity.

    Science.gov (United States)

    Galina, Antonio

    2014-09-01

    Enhanced glycolysis, the classic bioenergetic phenotype of cancer cells was described by Otto Warburg approximately 90 years ago. However, the Warburg hypothesis does not necessarily imply mitochondrial dysfunction. The alkyl-halogen, 3-bromopyruvate (3BP), would not be expected to have selective targets for cancer therapy due to its high potential reactivity toward many SH side groups. Contrary to predictions, 3BP interferes with glycolysis and oxidative phosphorylation in cancer cells without side effects in normal tissues. The mitochondrial hexokinase II has been claimed as the main target. This "Organelle in focus" article presents a historical view of the use of 3BP in biochemistry and its effects on ATP-producing pathways of cancer cells. I will discuss how the alkylated enzymes contribute to the cooperative collapse of mitochondria and apoptosis. Perspectives for targeting 3BP to bioenergetics enzymes for cancer treatment will be considered.

  19. Hydrogen Sulfide as an Endogenous Modulator in Mitochondria and Mitochondria Dysfunction

    Directory of Open Access Journals (Sweden)

    Wei Guo

    2012-01-01

    Full Text Available Hydrogen sulfide (H2S has historically been considered to be a toxic gas, an environmental and occupational hazard. However, with the discovery of its presence and enzymatic production through precursors of L-cysteine and homocysteine in mammalian tissues, H2S has recently received much interest as a physiological signaling molecule. H2S is a gaseous messenger molecule that has been implicated in various physiological and pathological processes in mammals, including vascular relaxation, angiogenesis, and the function of ion channels, ischemia/reperfusion (I/R, and heart injury. H2S is an endogenous neuromodulator and present studies show that physiological concentrations of H2S enhance NMDA receptor-mediated responses and aid in the induction of hippocampal long-term potentiation. Moreover, in the field of neuronal protection, physiological concentrations of H2S in mitochondria have many favorable effects on cytoprotection.

  20. Industrial Fuel Gas Demonstration Plant Program. Monthly and quarterly progress report, 1 April 1978-30 June 1978 (Deliverable No. 12)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-07-01

    The design of the commercial plant was completed and a cost estimate prepared. Most work remaining on Task I relates to: Demonstration Plant recommendations and includes a configuration study, at DOE's request, to evaluate alternatives for the Demo Plant Configuration to achieve the required reliability. The specific alternatives being considered are: A base U-Gas Plant designed to produce 50 MMM Btu/day 365 days per year (the High Reliability case); a base U-Gas Plant plus product storage; and a base U-Gas Plant, plus a small methanation facility to upgrade a small portion of the product to obtain credits. Other studies in support of the demonstration plant recommendations include: economic study of U-Gas versus coal-fired boilers for internal steam generation; an assessment of the cost/benefit of designing the Demo Plant for an operating pressure higher than the current data allows; and evaluation of the costs of providing a zero discharge wastewater treatment system.

  1. Research Progress of Natural Therapy for Disposition of Healthful Plants%自然疗法用于植物景观配置的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘丽

    2012-01-01

    文章介绍了自然疗法的定义、植物的保健功效及其在景观设计中的三种应用方式。并从视觉、听觉、嗅觉、触觉四方面功效选择保健型植物来构建康复疗养型景观的问题进行了研究和论述。%Be based on the introduction of nature therapy's definition and connotation, the health care function of plant and three kinds' applications of the healthful plants within landscape design have been introduced. In convalescing health care landscape, how to select plant species and deploy plant community from visual, audible, smelling and touch four aspects. Also introduces some harmful plants and flowers.

  2. 外来入侵植物小飞蓬化感作用机理研究的进展%The Progress of Studies on the Allelopathy Mechanism of Alien Invasive Plant Conyza Canadensis ( L. ) Cronq.

    Institute of Scientific and Technical Information of China (English)

    张海燕; 罗鑫; 张敏

    2015-01-01

    入侵植物会损害环境生态系统,影响生物的多样性,给农业生产带来严重的经济损失.目前,虽然入侵植物的化感作用研究较多,但是很多缺乏对化感作用的深入研究.结合国内外入侵植物的研究进展,该研究阐述了小飞蓬的研究现状、化感物质的分离鉴定方法以及入侵机理研究的进展.参24.%Alien invasive plants can damage the ecological environment system,have influence on the biological diversity and bring serious economic losses to the agricultural production. At present,there are many studies on the allelopathic effect of the invasive plants,but lack of deep research on the mechanism of allelopathy. Combined with the research progress of invasive plants at home and abroad,this paper in-troduce research actuality, methods of isolation, identification allelochemicals and the progress in the mechanism research of Conyza Canadensis. 24refs.

  3. ING1 induces apoptosis through direct effects at the mitochondria

    DEFF Research Database (Denmark)

    Bose, P; Thakur, S; Thalappilly, S

    2013-01-01

    translocates to the mitochondria of primary fibroblasts and established epithelial cell lines in response to apoptosis inducing stimuli, independent of the cellular p53 status. The ability of ING1 to induce apoptosis in various breast cancer cell lines correlates well with its degree of translocation......The ING family of tumor suppressors acts as readers and writers of the histone epigenetic code, affecting DNA repair, chromatin remodeling, cellular senescence, cell cycle regulation and apoptosis. The best characterized member of the ING family, ING1,interacts with the proliferating cell nuclear...... to the mitochondria after UV treatment. Endogenous ING1 protein specifically interacts with the pro-apoptotic BCL2 family member BAX, and colocalizes with BAX in a UV-inducible manner. Ectopic expression of a mitochondria-targeted ING1 construct is more proficient in inducing apoptosis than the wild type ING1 protein...

  4. Enzyme activities in mitochondria isolated from ripening tomato fruit.

    Science.gov (United States)

    Jeffery, D; Goodenough, P W; Weitzman, P D

    1986-09-01

    Mitochondria were isolated from tomato (Lycopersicon esculentum L.) fruit at the mature green, orange-green and red stages and from fruit artificially suspended in their ripening stage. The specific activities of citrate synthase (EC 4.1.3.7), malate dehydrogenase (EC 1.1.1.37), NAD-linked isocitrate dehydrogenase (EC 1.1.1.41) and NAD-linked malic enzyme (EC 1.1.1.38) were determined. The specific activities of all these enzymes fell during ipening, although the mitochondria were fully functional as demonstrated by the uptake of oxygen. The fall in activity of mitochondrial malate dehydrogenase was accompanied by a similar fall in the activity of the cytosolic isoenzyme. Percoll-purified mitochondria isolated from mature green fruit remained intact for more than one week and at least one enzyme, citrate synthase, did not exhibit the fall in specific activity found in normal ripening fruit.

  5. Assuming the role of mitochondria in mycobacterial infection.

    Science.gov (United States)

    Dubey, Rikesh K

    2016-12-01

    Tuberculosis is one of the leading causes of death by Mycobacterium tuberculosis (Mtb) affecting millions of people worldwide. Mycobacterium species enter host macrophages during infection and target various cellular organelles and their function for their own benefit. Mitochondria appear to be among the important targets for bacterial pathogens. Mtb and other pathogenic bacteria secrete various proteins that initiate structural changes in mitochondria to modulate its function. Additionally, virulent mycobacteria interfere with the balance between pro- and anti-apoptotic factors to inhibit apoptosis and, in later stages, promote necrosis. Furthermore, mitochondria perform multiple biological functions in the cell, and the inhibition of these functions by bacterial proteins promotes Mtb survival, growth, and successful infection. Copyright © 2016 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

  6. Statins lower calcium-induced oxidative stress in isolated mitochondria.

    Science.gov (United States)

    Parihar, A; Parihar, M S; Zenebe, W J; Ghafourifar, P

    2012-04-01

    Statins are widely used cholesterol-lowering agents that exert cholesterol-independent effects including antioxidative. The present study delineates the effects of statins, atorvastatin, and simvastatin on oxidative stress and functions of mitochondria that are the primary cellular sources of oxidative stress. In isolated rat liver mitochondria, both the statins prevented calcium-induced cytochrome c release, lipid peroxidation, and opening of the mitochondrial membrane permeability transition (MPT). Both the statins decreased the activity of mitochondrial nitric oxide synthase (mtNOS), lowered the intramitochondrial ionized calcium, and increased the mitochondrial transmembrane potential. Our findings suggest that statins lower intramitochondrial ionized calcium that decreases mtNOS activity, lowers oxidative stress, prevents MPT opening, and prevents the release of cytochrome c from the mitochondria. These results provide a novel framework for understanding the antioxidative properties of statins and their effects on mitochondrial functions.

  7. Exploiting mitochondria as targets for the development of new antifungals.

    Science.gov (United States)

    Li, Dongmei; Calderone, Richard

    2017-02-17

    Mitochondria are essential for cell growth and survival of most fungal pathogens. Energy (ATP) produced during oxidation/reduction reactions of the electron transport chain (ETC) Complexes I, III and IV (CI, CIII, CIV) fuel cell synthesis. The mitochondria of fungal pathogens are understudied even though more recent published data suggest critical functional assignments to fungal-specific proteins. Proteins of mammalian mitochondria are grouped into 16 functional categories. In this review, we focus upon 11 proteins from 5 of these categories in fungal pathogens, OXPHOS, protein import, stress response, carbon source metabolism, and fission/fusion morphology. As these proteins also are fungal-specific, we hypothesize that they may be exploited as targets in antifungal drug discovery. We also discuss published transcriptional profiling data of mitochondrial CI subunit protein mutants, in which we advance a novel concept those CI subunit proteins have both shared as well as specific responsibilities for providing ATP to cell processes.

  8. What cost mitochondria? The maintenance of functional mitochondrial DNA within and across generations.

    Science.gov (United States)

    Aanen, Duur K; Spelbrink, Johannes N; Beekman, Madeleine

    2014-07-05

    The peculiar biology of mitochondrial DNA (mtDNA) potentially has detrimental consequences for organismal health and lifespan. Typically, eukaryotic cells contain multiple mitochondria, each with multiple mtDNA genomes. The high copy number of mtDNA implies that selection on mtDNA functionality is relaxed. Furthermore, because mtDNA replication is not strictly regulated, within-cell selection may favour mtDNA variants with a replication advantage, but a deleterious effect on cell fitness. The opportunities for selfish mtDNA mutations to spread are restricted by various organism-level adaptations, such as uniparental transmission, germline mtDNA bottlenecks, germline selection and, during somatic growth, regular alternation between fusion and fission of mitochondria. These mechanisms are all hypothesized to maintain functional mtDNA. However, the strength of selection for maintenance of functional mtDNA progressively declines with age, resulting in age-related diseases. Furthermore, organismal adaptations that most probably evolved to restrict the opportunities for selfish mtDNA create secondary problems. Owing to predominantly maternal mtDNA transmission, recombination among mtDNA from different individuals is highly restricted or absent, reducing the scope for repair. Moreover, maternal inheritance precludes selection against mtDNA variants with male-specific effects. We finish by discussing the consequences of life-history differences among taxa with respect to mtDNA evolution and make a case for the use of microorganisms to experimentally manipulate levels of selection.

  9. Heme Binding Biguanides Target Cytochrome P450-Dependent Cancer Cell Mitochondria.

    Science.gov (United States)

    Guo, Zhijun; Sevrioukova, Irina F; Denisov, Ilia G; Zhang, Xia; Chiu, Ting-Lan; Thomas, Dafydd G; Hanse, Eric A; Cuellar, Rebecca A D; Grinkova, Yelena V; Langenfeld, Vanessa Wankhede; Swedien, Daniel S; Stamschror, Justin D; Alvarez, Juan; Luna, Fernando; Galván, Adela; Bae, Young Kyung; Wulfkuhle, Julia D; Gallagher, Rosa I; Petricoin, Emanuel F; Norris, Beverly; Flory, Craig M; Schumacher, Robert J; O'Sullivan, M Gerard; Cao, Qing; Chu, Haitao; Lipscomb, John D; Atkins, William M; Gupta, Kalpna; Kelekar, Ameeta; Blair, Ian A; Capdevila, Jorge H; Falck, John R; Sligar, Stephen G; Poulos, Thomas L; Georg, Gunda I; Ambrose, Elizabeth; Potter, David A

    2017-09-14

    The mechanisms by which cancer cell-intrinsic CYP monooxygenases promote tumor progression are largely unknown. CYP3A4 was unexpectedly associated with breast cancer mitochondria and synthesized arachidonic acid (AA)-derived epoxyeicosatrienoic acids (EETs), which promoted the electron transport chain/respiration and inhibited AMPKα. CYP3A4 knockdown activated AMPKα, promoted autophagy, and prevented mammary tumor formation. The diabetes drug metformin inhibited CYP3A4-mediated EET biosynthesis and depleted cancer cell-intrinsic EETs. Metformin bound to the active-site heme of CYP3A4 in a co-crystal structure, establishing CYP3A4 as a biguanide target. Structure-based design led to discovery of N1-hexyl-N5-benzyl-biguanide (HBB), which bound to the CYP3A4 heme with higher affinity than metformin. HBB potently and specifically inhibited CYP3A4 AA epoxygenase activity. HBB also inhibited growth of established ER(+) mammary tumors and suppressed intratumoral mTOR. CYP3A4 AA epoxygenase inhibition by biguanides thus demonstrates convergence between eicosanoid activity in mitochondria and biguanide action in cancer, opening a new avenue for cancer drug discovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Fe-S Cluster Biogenesis in Isolated Mammalian Mitochondria

    Science.gov (United States)

    Pandey, Alok; Pain, Jayashree; Ghosh, Arnab K.; Dancis, Andrew; Pain, Debkumar

    2015-01-01

    Iron-sulfur (Fe-S) clusters are essential cofactors, and mitochondria contain several Fe-S proteins, including the [4Fe-4S] protein aconitase and the [2Fe-2S] protein ferredoxin. Fe-S cluster assembly of these proteins occurs within mitochondria. Although considerable data exist for yeast mitochondria, this biosynthetic process has never been directly demonstrated in mammalian mitochondria. Using [35S]cysteine as the source of sulfur, here we show that mitochondria isolated from Cath.A-derived cells, a murine neuronal cell line, can synthesize and insert new Fe-35S clusters into aconitase and ferredoxins. The process requires GTP, NADH, ATP, and iron, and hydrolysis of both GTP and ATP is necessary. Importantly, we have identified the 35S-labeled persulfide on the NFS1 cysteine desulfurase as a genuine intermediate en route to Fe-S cluster synthesis. In physiological settings, the persulfide sulfur is released from NFS1 and transferred to a scaffold protein, where it combines with iron to form an Fe-S cluster intermediate. We found that the release of persulfide sulfur from NFS1 requires iron, showing that the use of iron and sulfur for the synthesis of Fe-S cluster intermediates is a highly coordinated process. The release of persulfide sulfur also requires GTP and NADH, probably mediated by a GTPase and a reductase, respectively. ATP, a cofactor for a multifunctional Hsp70 chaperone, is not required at this step. The experimental system described here may help to define the biochemical basis of diseases that are associated with impaired Fe-S cluster biogenesis in mitochondria, such as Friedreich ataxia. PMID:25398879

  11. Research Progress of Plant Non-host Resistance%植物非寄主抗性的研究进展

    Institute of Scientific and Technical Information of China (English)

    于建水; 封立波

    2012-01-01

    综述了植物非寄主抗性的类型和抗病机理,阐明了植物非寄主抗性在植物抗病中的作用,以期为培育稳定持久的抗性新品种提供理论和实践依据。%The article reviewed the type and the disease-resistant mechanism of plant non-host resistance,clarified the effect of plant non-host resistance in plant disease resistant,in order to provide theoretical and practical basis for breeding new stable and sustainable resistant breed.

  12. Identification and validation of heavy metal and radionuclide accumulating terrestrial plant species. Quarterly technical progress report, June 21, 1995--September 20, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Kochian, L.

    1995-12-31

    This quarterly report describes experiments on uptake of a variety of heavy metals by plants. Titles of report sections are (1) Alleviation of heavy-metal induced micronutrient deficiency through foliar fertilization, (2) Second screen for Zn, Cu, and Cd accumulation, (3) Characterization of the root Zn hyperaccumulation by Thlaspi caerulescens, (4) Comparison of commercial Brassica accessions obtained from the Iowa seed bank, (5) Second screening experiment for the accumulation of Cs and Sr by plants, (6) Effect of Ca on Cs and Sr accumulation by selected dicot species, and (7) Preliminary investigations into the forms of uranium taken up by plants.

  13. New nanocomposites for SERS studies of living cells and mitochondria

    DEFF Research Database (Denmark)

    Sarycheva, A. S.; Brazhe, N. A.; Baizhumanov, A. A.

    2016-01-01

    molecules. The SERS spectra of functional mitochondria are sensitive to the activity of the mitochondrial electron transport chain, thus making the method a novel label-free approach to monitor the redox state and conformation of cytochromes in their natural cell environment. The developed nanocomposites......A great enhancement in Raman scattering (SERS) from heme-containing submembrane biomolecules inside intact erythrocytes and functional mitochondria is demonstrated for the first time using silver–silica beads prepared using a new method involving aerosol pyrolysis with aqueous diamminesilver...

  14. The genome and transcriptome of perennial ryegrass mitochondria

    DEFF Research Database (Denmark)

    Islam, Md. Shofiqul; Studer, Bruno; Byrne, Stephen

    2013-01-01

    and annotation of the complete mitochondrial genome from perennial ryegrass. Results: Intact mitochondria from perennial ryegrass leaves were isolated and used for mtDNA extraction. The mitochondrial genome was sequenced to a 167-fold coverage using the Roche 454 GS-FLX Titanium platform, and assembled...... of the mitochondrial genome from perennial ryegrass presented here constitutes an important tool for future attempts to compare mitochondrial genomes within and between grass species. Our results also demonstrate that mitochondria of perennial ryegrass contain genes crucial for energy production that are well...

  15. Scavenging of H2O2 by mouse brain mitochondria.

    Science.gov (United States)

    Starkov, Anatoly A; Andreyev, Alexander Yu; Zhang, Steven F; Starkova, Natalia N; Korneeva, Maria; Syromyatnikov, Mikhail; Popov, Vasily N

    2014-12-01

    Mitochondrial reactive oxygen species (ROS) metabolism is unique in that mitochondria both generate and scavenge ROS. Recent estimates of ROS scavenging capacity of brain mitochondria are surprisingly high, ca. 9-12 nmol H2O2/min/mg, which is ~100 times higher than the rate of ROS generation. This raises a question whether brain mitochondria are a source or a sink of ROS. We studied the interaction between ROS generation and scavenging in mouse brain mitochondria by measuring the rate of removal of H2O2 added at a concentration of 0.4 μM, which is close to the reported physiological H2O2 concentrations in tissues, under conditions of low and high levels of mitochondrial H2O2 generation. With NAD-linked substrates, the rate of H2O2 generation by mitochondria was ~50-70 pmol/min/mg. The H2O2 scavenging dynamics was best approximated by the first order reaction equation. H2O2 scavenging was not affected by the uncoupling of mitochondria, phosphorylation of added ADP, or the genetic ablation of glutathione peroxidase 1, but decreased in the absence of respiratory substrates, in the presence of thioredoxin reductase inhibitor auranofin, or in partially disrupted mitochondria. With succinate, the rate of H2O2 generation was ~2,200-2,900 pmol/min/mg; the scavenging of added H2O2 was masked by a significant accumulation of generated H2O2 in the assay medium. The obtained data were fitted into a simple model that reasonably well described the interaction between H2O2 scavenging and production. It showed that mitochondria are neither a sink nor a source of H2O2, but can function as both at the same time, efficiently stabilizing exogenous H2O2 concentration at a level directly proportional to the ratio of the H2O2 generation rate to the rate constant of the first order scavenging reaction.

  16. Identification and validation of heavy metal and radionuclide hyperaccumulating terrestrial plant species. Quarterly technical progress report, March 20, 1995--June 20, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Kochian, L.

    1995-12-01

    The biological accumulation of heavy metals and cesium, strontium, and uranium in plants is discussed. The role of nutrient deficiencies and foliar treatments of manganese and iron compounds is described.

  17. Erythroid precursors from patients with low-risk myelodysplasia demonstrate ultrastructural features of enhanced autophagy of mitochondria

    NARCIS (Netherlands)

    Houwerzijl, E. J.; Pol, H-W D.; Blom, N. R.; van der Want, J. J. L.; de Wolf, J. Thm; Vellenga, E.

    Recent studies in erythroid cells have shown that autophagy is an important process for the physiological clearance of mitochondria during terminal differentiation. However, autophagy also plays an important role in removing damaged and dysfunctional mitochondria. Defective mitochondria and impaired

  18. Interagency partnering for weed prevention--progress on development of a National Early Detection and Rapid Response System for Invasive Plants in the United States

    Science.gov (United States)

    Westbrooks, R.; Westbrooks, R.

    2011-01-01

    Over the past 50 years, experience has shown that interagency groups provide an effective forum for addressing various invasive species issues and challenges on multiple land units. However, more importantly, they can also provide a coordinated framework for early detection, reporting, identification and vouchering, rapid assessment, and rapid response to new and emerging invasive plants in the United States. Interagency collaboration maximizes the use of available expertise, resources, and authority for promoting early detection and rapid response (EDRR) as the preferred management option for addressing new and emerging invasive plants. Currently, an interagency effort is underway to develop a National EDRR System for Invasive Plants in the United States. The proposed system will include structural and informational elements. Structural elements of the system include a network of interagency partner groups to facilitate early detection and rapid response to new invasive plants, including the Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW), State Invasive Species Councils, State Early Detection and Rapid Response Coordinating Committees, State Volunteer Detection and Reporting Networks, Invasive Plant Task Forces, and Cooperative Weed Management Areas. Informational elements and products being developed include Regional Invasive Plant Atlases, and EDRR Guidelines for EDRR Volunteer Network Training, Rapid Assessment and Rapid Response, and Criteria for Selection of EDRR Species. System science and technical support elements which are provided by cooperating state and federal scientists, include EDRR guidelines, training curriculum for EDRR volunteers and agency field personnel, plant identification and vouchering, rapid assessments, as well as predictive modeling and ecological range studies for invasive plant species.

  19. Progress of study on the relationship between sulfur nutrition and plant diseases%硫素营养与植物病害关系研究进展

    Institute of Scientific and Technical Information of China (English)

    王梅; 尹显慧; 龙友华; 田雪莲; 朱流红

    2015-01-01

    Sulfur is one of the important nutritional elements for the plant growth and development, and is the structural ingredient of many physiological active substances. Sulfur involves in important physiological and biological process, including in the expression of the plant cellular membrane structure, the protein metabo-lism and regulating enzyme activity. It directly or indirectly affects the ability of plant resistance to diseases in many ways. This article further explains the impact of sulfur nutrition on the ability of plant resistance to dis-eases from the aspects of absorbing, assimilation and redistribution of the sulfur in plants and the influence of sulfur nutrition on plant growth. The review provides useful references for further study on the relationship be-tween sulfur and plant diseases, so that sulfur nutrition would play more important role in controlling plant diseases.%硫是植物生长发育过程中重要的营养元素之一,是许多生理活性物质的组成成分,参与了植物细胞质膜结构的表达、蛋白质代谢和酶活性调节等重要生理生化过程,以多种方式直接或间接地影响植物的抗病性。本文从硫在植物体内的吸收、同化和再分配,硫素营养对植物生长的影响,进一步阐述硫素对植物抗病性的影响,为硫素营养与植物病害关系的深入研究提供借鉴,以期硫素在控制病害方面发挥更大的作用。

  20. Peeping at TOMs-Diverse Entry Gates to Mitochondria Provide Insights into the Evolution of Eukaryotes.

    Science.gov (United States)

    Mani, Jan; Meisinger, Chris; Schneider, André

    2016-02-01

    Mitochondria are essential for eukaryotic life and more than 95% of their proteins are imported as precursors from the cytosol. The targeting signals for this posttranslational import are conserved in all eukaryotes. However, this conservation does not hold true for the protein translocase of the mitochondrial outer membrane that serves as entry gate for essentially all precursor proteins. Only two of its subunits, Tom40 and Tom22, are conserved and thus likely were present in the last eukaryotic common ancestor. Tom7 is found in representatives of all supergroups except the Excavates. This suggests that it was added to the core of the translocase after the Excavates segregated from all other eukaryotes. A comparative analysis of the biochemically and functionally characterized outer membrane translocases of yeast, plants, and trypanosomes, which represent three eukaryotic supergroups, shows that the receptors that recognize the conserved import signals differ strongly between the different systems. They present a remarkable example of convergent evolution at the molecular level. The structural diversity of the functionally conserved import receptors therefore provides insight into the early evolutionary history of mitochondria. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. AtKP1, a kinesin-like protein, mainly localizes to mitochondria in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Kinesins and kinesin-like proteins (KLPs) constitute a large family of microtubule-based motors that play important roles in many fundamental cellular and developmental processes. To date, a number of kinesins or KLPs have been identified in plants including Arabidopsis thaliana. Here, a polyclonal antibody against AtKP1 (kinesin-like protein 1 in A.thaliana) was raised by injection the expressed AtKP1 specific C-terminal polypeptides in rabbits, and immunoblot analysis was conducted with the affinity-purified anti-AtKP1 antibody. The results indicated that this antibody recognized the AtKP1 fusion proteins expressed in E. coli and proteins of ~125 kDa in the soluble fractions of Arabidopsis extracts. The molecular weight was consistent with the calculated molecular weight based on deduced amino acids sequence of AtKP1. To acquire the subcellular localization of the protein, AtKP1 in Arabidopsis root cells was observed by indirect immunofluorescence microscopy. AtKP1 was localized to particle-like organelles in interphase or dividing cells, but not to mitotic microtubule arrays. Relatively more AtKP1 was found in isolated mitochondria fraction on immunoblot of the subcellular fractions. The AtKP1 protein could not be released following a 0.6 M KI washing,indicating that AtKP1 is tightly bind to mitochondria and might function associated with this kind of organelles.

  2. Roles of Protein Synthesis Elongation Factor EF-Tu in Heat Tolerance in Plants

    Directory of Open Access Journals (Sweden)

    Jianming Fu

    2012-01-01

    Full Text Available EF-Tu proteins of plastids, mitochondria, and the cytosolic counterpart EF-1α in plants, as well as EF-Tu proteins of bacteria, are highly conserved and multifunctional. The functions of EF-Tu include transporting the aminoacyl-tRNA complex to the A site of the ribosome during protein biosynthesis; chaperone activity in protecting other proteins from aggregation caused by environmental stresses, facilitating renaturation of proteins when conditions return to normal; displaying a protein disulfide isomerase activity; participating in the degradation of N-terminally blocked proteins by the proteasome; eliciting innate immunity and triggering resistance to pathogenic bacteria in plants; participating in transcription when an E. coli host is infected with phages. EF-Tu genes are upregulated by abiotic stresses in plants, and EF-Tu plays important role in stress responses. Expression of a plant EF-Tu gene confers heat tolerance in E. coli, maize knock-out EF-Tu null mutants are heat susceptible, and over-expression of an EF-Tu gene improves heat tolerance in crop plants. This review paper summarizes the current knowledge of EF-Tu proteins in stress responses in plants and progress on application of EF-Tu for developing crop varieties tolerant to abiotic stresses, such as high temperatures.

  3. Mitochondrial biogenesis in plants during seed germination.

    Science.gov (United States)

    Law, Simon R; Narsai, Reena; Whelan, James

    2014-11-01

    Mitochondria occupy a central role in the eukaryotic cell. In addition to being major sources of cellular energy, mitochondria are also involved in a diverse range of functions including signalling, the synthesis of many essential organic compounds and a role in programmed cell death. The active proliferation and differentiation of mitochondria is termed mitochondrial biogenesis and necessitates the coordinated communication of mitochondrial status within an integrated cellular network. Two models of mitochondrial biogenesis have been defined previously, the growth and division model and the maturation model. The former describes the growth and division of pre-existing mature organelles through a form of binary fission, while the latter describes the propagation of mitochondria from structurally and biochemically simple promitochondrial structures that upon appropriate stimuli, mature into fully functional mitochondria. In the last decade, a number of studies have utilised seed germination in plants as a platform for the examination of the processes occurring during mitochondrial biogenesis. These studies have revealed many new aspects of the tightly regulated procession of events that define mitochondrial biogenesis during this period of rapid development. A model for mitochondrial biogenesis that supports the maturation of mitochondria from promitochondrial structures has emerged, where mitochondrial signalling plays a crucial role in the early steps of seed germination.

  4. Research Progress of the Influence of Plant Functional Components on Bread Processing Quality%植物功能成分对面包加工品质影响的研究进展

    Institute of Scientific and Technical Information of China (English)

    章斌

    2015-01-01

    综述植物源功能性成分(功能性糖类、多酚类、其它功能性提取物等)对面团加工性能及面包品质影响的研究概况,并对一些研究方向进行展望.%Recent research situation and progress of effects on processing properties of dough and bread quality by functional components and extracts from plants such as functional carbohydrates and polyphenols etc. were summarized in this paper. Meanwhile, future development prospects and research directions are forecasted.

  5. TRAP1 ameliorates renal tubulointerstitial fibrosis in mice with unilateral ureteral obstruction by protecting renal tubular epithelial cell mitochondria.

    Science.gov (United States)

    Chen, Jun-Feng; Wu, Qi-Shun; Xie, Yu-Xian; Si, Bo-Lin; Yang, Ping-Ping; Wang, Wen-Yan; Hua, Qin; He, Qing

    2017-10-01

    Mitochondrial dysfunction causes renal tubular epithelial cell injury and promotes cell apoptosis and renal tubulointerstitial fibrosis (TIF) progression. TNF receptor-associated protein 1 (TRAP1) is a molecular chaperone protein that is localized in mitochondria. It plays an important role in cell apoptosis; however, its functional mechanism in TIF remains unclear. In this study, we observed the effects of TRAP1 in renal tubular epithelial cell mitochondria in mice with unilateral ureteral obstruction and its function in cell apoptosis and TIF. Results show that TRAP1 could protect the mitochondrial structure in renal tubular epithelial cells; maintain the levels of mitochondrial membrane potential, ATP, and mitochondrial DNA copy number; inhibit reactive oxygen species production; stabilize the expression of the mitochondrial inner membrane protein mitofilin; reduce renal tubular epithelial cell apoptosis; and inhibit TIF. These results provide new theoretical foundations for additional understanding of the antifibrotic mechanism of TRAP1 in the kidney.-Chen, J.-F., Wu, Q.-S., Xie, Y.-X., Si, B.-L., Yang, P.-P., Wang, W.-Y., Hua, Q., He, Q. TRAP1 ameliorates renal tubulointerstitial fibrosis in mice with unilateral ureteral obstruction by protecting renal tubular epithelial cell mitochondria. © FASEB.

  6. 植物与微生物互作的研究进展%Research Progress of Interaction between Plant and Microorganism

    Institute of Scientific and Technical Information of China (English)

    国辉; 毛志泉; 刘训理

    2011-01-01

    Plants and the microorganisms in their growth environment have close relationships, which form the plant-microorganism symbiont system and interact mutually. Plants affect microbial community composition in the surroundings and the microorganisms also have an influence on plant growth. It is of great importance for agricultural production to understand and recognize the interaction between plants and microorganisms. This paper reviewed the effects of plant types and root exudates on the microbial community composition and diversity, stated the influences of rhizosphere microbes, phyllosphere microbe and endophyte (including the endophytic fungus, the endophytic bacteria and the endophytic actinomycete) on plant growth, and prospected the related research interests in the future.%植物与其生长环境中的微生物关系密切,两者形成了植物一微生物共生体系统.植物影响着其周围及体内的微生物的群落结构,这些微生物又通过其生命活动影响植物的生长发育.了解与认识植物与微生物的相互作用对于农业生产具有重要意义.笔者就植物类型及植物根系分泌物对微生物群落结构及多样性的影响,植物根际微生物、叶围微生物和内生菌(包括内生真菌、内生细菌以及内生放线茵)对植物生长发育的影响等进行综述,并就其将来的研究方向做了展望.

  7. Progress on the Stress-resistant Ecological Function of Plant Polyphenols%植物多酚抗逆生态作用研究进展

    Institute of Scientific and Technical Information of China (English)

    徐国前; 张振文; 郭安鹊; 栾丽英

    2011-01-01

    Plant polyphenols are the important secondary metabolites of plants,not only responsible for absorbing excessive solar irradiation, screening solar ultra-violet radiation, scavenging free radicals, but also contributing to attracting pollinators, fertilization and seed dispersal. This paper reviewed the advanced research about the stress ecological function of plant polyphenols,mainly including that they play important agents as defense against the biotic or abiotic stressors, such as nutrient deficiency, drought, temperature variations, salt injury, atmosphere pollution, herbivores and pathogen infection stress, as well as information substance between plants and plants or plant with the living environment. Meanwhile, the application prospect of plant polyphenols was discussed.%植物多酚是一类重要的植物次生代谢物质,具有吸收过多的太阳辐射、过滤UV(ultra-violet)和清除体内自由基等多种生理功能,有利于传播花粉、受精及传播种子,并在植物逆境生理生态上也具有重要的作用.该文对近年来国内外有关植物多酚在逆境生态中抗生物或非生物胁迫中的作用--主要包括作为缓解营养缺乏、抵抗干旱、温度变化、盐害、大气污染、食草动物和病原菌浸染等逆境胁迫时的防御物质,以及作为植物与植物之间以及植物与环境之间信息交流物质等方面的研究进展进行综述,并展望了植物多酚的应用前景.

  8. Progress of Effects of Leaf Anthocyanins on Plant Photosynthesis%叶片花色素苷对植物光合作用影响的研究进展

    Institute of Scientific and Technical Information of China (English)

    谢智华; 姜卫兵; 韩键; 翁忙玲

    2011-01-01

    近年来,花色素苷在彩叶植物呈色机制的研究中备受关注,但目前有关其对彩叶植物光合特性影响的机制仍缺乏系统的评述.本文简单介绍了花色素苷的基本特性,并基于国内外相关研究进展,综述了叶片花色素苷对植物光合特性的影响机制及其对叶片光合机构的保护意义,对彩叶植物光合作用的研究方向提出了建议.%The studies on roles of anthocyanins in the coloration of colored-leaf plants have been popularly reported. However, the mechanism about the influence of anthocyanins on plant photosynthesis has not been thoroughly introduced. Based on the progress in the related studies, this paper briefly introduces the characteristics of anthocyanins, and further reviews the influences of anthocyanins on plant photosynthesis. The important roles of anthocyanins in protecting photosynthetic apparatus are also presented. At last, some suggestions about further key researches on the photosynthesis of colored-leaf plants are put forward.

  9. Microscopic neural image registration based on the structure of mitochondria

    Science.gov (United States)

    Cao, Huiwen; Han, Hua; Rao, Qiang; Xiao, Chi; Chen, Xi

    2017-02-01

    Microscopic image registration is a key component of the neural structure reconstruction with serial sections of neural tissue. The goal of microscopic neural image registration is to recover the 3D continuity and geometrical properties of specimen. During image registration, various distortions need to be corrected, including image rotation, translation, tissue deformation et.al, which come from the procedure of sample cutting, staining and imaging. Furthermore, there is only certain similarity between adjacent sections, and the degree of similarity depends on local structure of the tissue and the thickness of the sections. These factors make the microscopic neural image registration a challenging problem. To tackle the difficulty of corresponding landmarks extraction, we introduce a novel image registration method for Scanning Electron Microscopy (SEM) images of serial neural tissue sections based on the structure of mitochondria. The ellipsoidal shape of mitochondria ensures that the same mitochondria has similar shape between adjacent sections, and its characteristic of broad distribution in the neural tissue guarantees that landmarks based on the mitochondria distributed widely in the image. The proposed image registration method contains three parts: landmarks extraction between adjacent sections, corresponding landmarks matching and image deformation based on the correspondences. We demonstrate the performance of our method with SEM images of drosophila brain.

  10. Phosphorylation of formate dehydrogenase in potato tuber mitochondria

    DEFF Research Database (Denmark)

    Bykova, N.V.; Stensballe, A.; Egsgaard, H.

    2003-01-01

    Two highly phosphorylated proteins were detected after two-dimensional (blue native/SDS-PAGE) gel electrophoretic separation of the matrix fraction isolated from potato tuber mitochondria. These two phosphoproteins were identified by mass spectrometry as formate dehydrogenase (FDH) and the E1alpha...

  11. Accumulation of pyruvate by isolated rat liver mitochondria

    NARCIS (Netherlands)

    Vaartjes, W.J.; Geelen, M.J.H.; Bergh, S.G. van den

    1979-01-01

    1. 1. Various methods to measure the rate of accumulation of [3-14C]pyruvate in the sucrose-impermeable space of isolated rat liver mitochondria are tested and compared with respect to their ability to distinguish between carrier-linked pyruvate transport and non-carrier-linked processes (adsorption

  12. Rejuvenating cellular respiration for optimizing respiratory function: targeting mitochondria.

    Science.gov (United States)

    Agrawal, Anurag; Mabalirajan, Ulaganathan

    2016-01-15

    Altered bioenergetics with increased mitochondrial reactive oxygen species production and degradation of epithelial function are key aspects of pathogenesis in asthma and chronic obstructive pulmonary disease (COPD). This motif is not unique to obstructive airway disease, reported in related airway diseases such as bronchopulmonary dysplasia and parenchymal diseases such as pulmonary fibrosis. Similarly, mitochondrial dysfunction in vascular endothelium or skeletal muscles contributes to the development of pulmonary hypertension and systemic manifestations of lung disease. In experimental models of COPD or asthma, the use of mitochondria-targeted antioxidants, such as MitoQ, has substantially improved mitochondrial health and restored respiratory function. Modulation of noncoding RNA or protein regulators of mitochondrial biogenesis, dynamics, or degradation has been found to be effective in models of fibrosis, emphysema, asthma, and pulmonary hypertension. Transfer of healthy mitochondria to epithelial cells has been associated with remarkable therapeutic efficacy in models of acute lung injury and asthma. Together, these form a 3R model--repair, reprogramming, and replacement--for mitochondria-targeted therapies in lung disease. This review highlights the key role of mitochondrial function in lung health and disease, with a focus on asthma and COPD, and provides an overview of mitochondria-targeted strategies for rejuvenating cellular respiration and optimizing respiratory function in lung diseases. Copyright © 2016 the American Physiological Society.

  13. Mitochondria mediate septin cage assembly to promote autophagy of Shigella.

    Science.gov (United States)

    Sirianni, Andrea; Krokowski, Sina; Lobato-Márquez, Damián; Buranyi, Stephen; Pfanzelter, Julia; Galea, Dieter; Willis, Alexandra; Culley, Siân; Henriques, Ricardo; Larrouy-Maumus, Gerald; Hollinshead, Michael; Sancho-Shimizu, Vanessa; Way, Michael; Mostowy, Serge

    2016-07-01

    Septins, cytoskeletal proteins with well-characterised roles in cytokinesis, form cage-like structures around cytosolic Shigella flexneri and promote their targeting to autophagosomes. However, the processes underlying septin cage assembly, and whether they influence S. flexneri proliferation, remain to be established. Using single-cell analysis, we show that the septin cages inhibit S. flexneri proliferation. To study mechanisms of septin cage assembly, we used proteomics and found mitochondrial proteins associate with septins in S. flexneri-infected cells. Strikingly, mitochondria associated with S. flexneri promote septin assembly into cages that entrap bacteria for autophagy. We demonstrate that the cytosolic GTPase dynamin-related protein 1 (Drp1) interacts with septins to enhance mitochondrial fission. To avoid autophagy, actin-polymerising Shigella fragment mitochondria to escape from septin caging. Our results demonstrate a role for mitochondria in anti-Shigella autophagy and uncover a fundamental link between septin assembly and mitochondria. © 2016 The Authors. Published under the terms of the CC BY 4.0 license.

  14. Endoplasmic reticulum-mitochondria junction is required for iron homeostasis.

    Science.gov (United States)

    Xue, Yong; Schmollinger, Stefan; Attar, Narsis; Campos, Oscar A; Vogelauer, Maria; Carey, Michael F; Merchant, Sabeeha S; Kurdistani, Siavash K

    2017-08-11

    The endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) is a protein complex that physically tethers the two organelles to each other and creates the physical basis for communication between them. ERMES functions in lipid exchange between the ER and mitochondria, protein import into mitochondria, and maintenance of mitochondrial morphology and genome. Here, we report that ERMES is also required for iron homeostasis. Loss of ERMES components activates an Aft1-dependent iron deficiency response even in iron-replete conditions, leading to accumulation of excess iron inside the cell. This function is independent of known ERMES roles in calcium regulation, phospholipid biosynthesis, or effects on mitochondrial morphology. A mutation in the vacuolar protein sorting 13 (VPS13) gene that rescues the glycolytic phenotype of ERMES mutants suppresses the iron deficiency response and iron accumulation. Our findings reveal that proper communication between the ER and mitochondria is required for appropriate maintenance of cellular iron levels. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. [Metabolic changes in pulmonary mitochondria of rats with experimental hyperhomocysteinemia].

    Science.gov (United States)

    Medvedev, D V; Zvyagina, V I; Uryasev, O M; Belskikh, E S; Bulatetskiy, S V; Ryabkov, A N

    2017-05-01

    Hyperhomocysteinemia is a risk factor for many human diseases, including pulmonary pathologies. In this context much interest attracts secondary mitochondrial dysfunction, which is an important link in pathogenesis of diseases associated with hyperhomocysteinemia. The study was conducted using male Wistar rats. It was found that under conditions of severe hyperhomocysteinemia caused by administration of methionine, homocysteine was accumulated in lung mitochondria thus suggesting a direct toxic effect on these organelles. However, we have not observed any significant changes in the activity of mitochondrial enzymes involved in tissue respiration (succinate dehydrogenase) and oxidative phosphorylation (H+-ATPase) and of cytoplasmic lactate dehydrogenase. Also there was no accumulation of lactic acid in the cytoplasm. Animals with severe hyperhomocysteinemia had higher levels of lung mitochondrial protein carbonylation, decreased reserve-adaptive capacity, and increased superoxide dismutase activity. These results indicate that severe hyperhomocysteinemia causes development of oxidative stress in lung mitochondria, which is compensated by activation of antioxidant protection. These changes were accompanied by a decrease in the concentration of mitochondrial nitric oxide metabolites. Introduction to animals a nonselective NO-synthase inhibitor L-NAME caused similar enhancement of mitochondrial protein carbonylation. It demonstrates importance of reducing bioavailability of nitric oxide, which is an antioxidant in physiological concentrations, in the development of oxidative stress in lung mitochondria during hyperhomocysteinemia. Key words: hyperhomocysteinemia, nitric oxide, lung, oxidative stress, mitochondria.

  16. Connection of Protein Transport and Organelle Contact Sites in Mitochondria.

    Science.gov (United States)

    Ellenrieder, Lars; Rampelt, Heike; Becker, Thomas

    2017-07-07

    Mitochondrial biogenesis and function depend on the intensive exchange of molecules with other cellular compartments. The mitochondrial outer membrane plays a central role in this communication process. It is equipped with a number of specific protein machineries that enable the transport of proteins and metabolites. Furthermore, the outer membrane forms molecular contact sites with other cell organelles like the endoplasmic reticulum (ER), thus integrating mitochondrial function in cellular physiology. The best-studied mitochondrial organelle contact site, the ER-mitochondria encounter structure (ERMES) has been linked to many vital processes including mitochondrial division, inheritance, mitophagy, and phospholipid transport. Strikingly, ER-mitochondria contact sites are closely connected to outer membrane protein translocases. The translocase of the outer mitochondrial membrane (TOM) represents the general mitochondrial entry gate for precursor proteins that are synthesized on cytosolic ribosomes. The outer membrane also harbors the sorting and assembly machinery (SAM) that mediates membrane insertion of β-barrel proteins. Both of these essential protein translocases are functionally linked to ER-mitochondria contact sites. First, the SAM complex associates with an ERMES core component to promote assembly of the TOM complex. Second, several TOM components have been co-opted as ER-mitochondria tethers. We propose that protein import and organelle contact sites are linked to coordinate processes important for mitochondrial biogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Detection of heteroplasmic mitochondrial DNA in single mitochondria.

    Directory of Open Access Journals (Sweden)

    Joseph E Reiner

    Full Text Available BACKGROUND: Mitochondrial DNA (mtDNA genome mutations can lead to energy and respiratory-related disorders like myoclonic epilepsy with ragged red fiber disease (MERRF, mitochondrial myopathy, encephalopathy, lactic acidosis and stroke (MELAS syndrome, and Leber's hereditary optic neuropathy (LHON. It is not well understood what effect the distribution of mutated mtDNA throughout the mitochondrial matrix has on the development of mitochondrial-based disorders. Insight into this complex sub-cellular heterogeneity may further our understanding of the development of mitochondria-related diseases. METHODOLOGY: This work describes a method for isolating individual mitochondria from single cells and performing molecular analysis on that single mitochondrion's DNA. An optical tweezer extracts a single mitochondrion from a lysed human HL-60 cell. Then a micron-sized femtopipette tip captures the mitochondrion for subsequent analysis. Multiple rounds of conventional DNA amplification and standard sequencing methods enable the detection of a heteroplasmic mixture in the mtDNA from a single mitochondrion. SIGNIFICANCE: Molecular analysis of mtDNA from the individually extracted mitochondrion demonstrates that a heteroplasmy is present in single mitochondria at various ratios consistent with the 50/50 heteroplasmy ratio found in single cells that contain multiple mitochondria.

  18. Mitochondria in metabolic disease: getting clues from proteomic studies.

    Science.gov (United States)

    Peinado, Juan R; Diaz-Ruiz, Alberto; Frühbeck, Gema; Malagon, Maria M

    2014-03-01

    Mitochondria play a key role as major regulators of cellular energy homeostasis, but in the context of mitochondrial dysfunction, mitochondria may generate reactive oxidative species and induce cellular apoptosis. Indeed, altered mitochondrial status has been linked to the pathogenesis of several metabolic disorders and specially disorders related to insulin resistance, such as obesity, type 2 diabetes, and other comorbidities comprising the metabolic syndrome. In the present review, we summarize information from various mitochondrial proteomic studies of insulin-sensitive tissues under different metabolic states. To that end, we first focus our attention on the pancreas, as mitochondrial malfunction has been shown to contribute to beta cell failure and impaired insulin release. Furthermore, proteomic studies of mitochondria obtained from liver, muscle, and adipose tissue are summarized, as these tissues constitute the primary insulin target metabolic tissues. Since recent advances in proteomic techniques have exposed the importance of PTMs in the development of metabolic disease, we also present information on specific PTMs that may directly affect mitochondria during the pathogenesis of metabolic disease. Specifically, mitochondrial protein acetylation, phosphorylation, and other PTMs related to oxidative damage, such as nitrosylation and carbonylation, are discussed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Method for functional study of mitochondria in rat hypothalamus.

    Science.gov (United States)

    Benani, Alexandre; Barquissau, Valentin; Carneiro, Lionel; Salin, Bénédicte; Colombani, Anne-Laure; Leloup, Corinne; Casteilla, Louis; Rigoulet, Michel; Pénicaud, Luc

    2009-04-15

    Different roles of mitochondria in brain function according to brain area are now clearly emerging. Unfortunately, no technique is yet described to investigate mitochondria function in specific brain area. In this article, we provide a complete description of a procedure to analyze the mitochondrial function in rat brain biopsies. Our two-step method consists in a saponin permeabilization of fresh brain tissues in combination with high-resolution respirometry to acquire the integrated respiratory rate of the biopsy. In the first part, we carefully checked the mitochondria integrity after permeabilization, defined experimental conditions to determine the respiratory control ratio (RCR), and tested the reproducibility of this technique. In the second part, we applied our method to test its sensitivity. As a result, this method was sensitive enough to reveal region specificity of mitochondrial respiration within the brain. Moreover, we detected physiopathological modulation of the mitochondrial function in the hypothalamus. Thus this new technique that takes all cell types into account, and does not discard or select any mitochondria sub-population is very suitable to analyze the integrated mitochondrial respiration of brain biopsies.

  20. Impacts of high ATP supply from chloroplasts and mitochondria on the leaf metabolism of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Chao eLiang

    2015-10-01

    Full Text Available Chloroplasts and mitochondria are the major ATP producing organelles in plant leaves. Arabidopsis thaliana purple acid phosphatase 2 (AtPAP2 is a phosphatase dually targeted to the outer membranes of both organelles and it plays a role in the import of selected nuclear-encoded proteins into these two organelles. Overexpression (OE of AtPAP2 in Arabidopsis thaliana accelerates plant growth and promotes flowering, seed yield and biomass at maturity. Measurement of ADP/ATP/NADP+/NADPH contents in the leaves of 20-day-old OE and wild-type lines at the end of night and at 1 and 8 h following illumination in a 16/8 h photoperiod revealed that the ATP levels and ATP/NADPH ratios were significantly increased in the OE line at all three time points. The AtPAP2 OE line is therefore a good model to investigate the impact of high energy on the global molecular status of Arabidopsis. In this study, transcriptome, proteome and metabolome profiles of the high ATP transgenic line were examined and compared with those of wild-type plants. A comparison of OE and WT at the end of the night provide valuable information on the impact of higher ATP output from mitochondria on plant physiology, as mitochondrial respiration is the major source of ATP in the dark in leaves. Similarly, comparison of OE and WT following illumination will provide information on the impact of higher energy output from chloroplasts on plant physiology. Overexpression of AtPAP2 was found to significantly affect the transcript and protein abundances of genes encoded by the two organellar genomes. For example, the protein abundances of many ribosomal proteins encoded by the chloroplast genome were higher in the AtPAP2 OE line under both light and dark conditions, while the protein abundances of multiple components of the photosynthetic complexes were lower. RNA-seq data also showed that the transcription of the mitochondrial genome is greatly affected by the availability of energy. These data