Plant Uncoupling Mitochondrial Protein and Alternative Oxidase: Energy Metabolism and Stress

Borecký, Jiřı́; Vercesi, Anı́bal E.

doi:10.1007/s10540-005-2889-2

Cited by 53 publications

(27 citation statements)

References 137 publications

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“…Alternative ubiquinol oxidases directly transfer electrons from ubiquinol to oxygen. AOXs have been documented to occur in plants (4,65,74), algae (71), yeasts (75), free-living amoebae (25), and protozoa (69) as well as in pathogenic fungi, such as Aspergillus fumigatus (72), H. capsulatum (27,38), and P. brasiliensis (17,39,40,42).…”

Section: Discussionmentioning

confidence: 99%

Involvement of an Alternative Oxidase in Oxidative Stress and Mycelium-to-Yeast Differentiation in Paracoccidioides brasiliensis

et al. 2011

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Paracoccidioides brasiliensis is a thermodimorphic human pathogenic fungus that causes paracoccidioidomycosis (PCM), which is the most prevalent systemic mycosis in Latin America. Differentiation from the mycelial to the yeast form (M-to-Y) is an essential step for the establishment of PCM. We evaluated the involvement of mitochondria and intracellular oxidative stress in M-to-Y differentiation. M-to-Y transition was delayed by the inhibition of mitochondrial complexes III and IV or alternative oxidase (AOX) and was blocked by the association of AOX with complex III or IV inhibitors. The expression of P. brasiliensis aox (Pbaox) was developmentally regulated through M-to-Y differentiation, wherein the highest levels were achieved in the first 24 h and during the yeast exponential growth phase; Pbaox was upregulated by oxidative stress. Pbaox was cloned, and its heterologous expression conferred cyanide-resistant respiration in Saccharomyces cerevisiae and Escherichia coli and reduced oxidative stress in S. cerevisiae cells. These results reinforce the role of PbAOX in intracellular redox balancing and demonstrate its involvement, as well as that of other components of the mitochondrial respiratory chain complexes, in the early stages of the M-to-Y differentiation of P. brasiliensis.Paracoccidioides brasiliensis, which is a thermally dimorphic fungus, is the etiological agent of paracoccidioidomycosis (PCM), which is the most prevalent human systemic mycosis in Latin America (5, 52) and affects almost 10 million individuals in Latin America (54). It is acquired by the inhalation of airborne microconidia, which reach the pulmonary alveolar epithelium and transform into the pathogenic yeast form (52,54,59). The human form of PCM that is caused by this fungus is characterized by a range of clinical manifestations, ranging from asymptomatic forms to severe, disseminated, and often fatal disease. Usually, fibrosis sequelae in the affected organs may interfere with the well-being of the patient (50).During infection, thermodimorphic fungi, such as Histoplasma capsulatum, Blastomyces dermatitidis, and P. brasiliensis, differentiate from a mycelial into a pathogenic yeast form, a transition that can also be induced (in vitro) by temperature changes from between 23 and 26°C to between 35 and 37°C. In addition, these pathogens are often subjected to significant environmental stresses, including exposure to the reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are produced by the host cells (6,27,45).Elevated sublethal temperatures (thermal stress or heat shock) increase ROS generation and oxidative damage in a variety of eukaryotic cells (16,49,60,73). Mitochondria are the primary intracellular sources of ROS, which are generated in respiratory chain complexes I and III and can damage biomolecules, such as nucleic acids, lipids, and proteins (20)(21)(22). In order to control ROS levels, cells employ diverse detoxification mechanisms, including superoxide dismutase, catalase, the glutathione/thioredoxin...

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Section: Discussionmentioning

confidence: 99%

Involvement of an Alternative Oxidase in Oxidative Stress and Mycelium-to-Yeast Differentiation in Paracoccidioides brasiliensis

et al. 2011

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“…On the other hand, cyanide is a byproduct of ethylene biosynthesis. Thus plants are able to sustain and detoxify cyanide produced under physiological conditions (Grossmann 1996, Borecký andVercesi 2005).…”

Section: Introductionmentioning

confidence: 99%

Cell death induced by sodium nitroprusside and hydrogen peroxide in tobacco BY-2 cell suspension

Víteček¹,

Wünschová²,

Petřek³

et al. 2007

Biol. plant.

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The interplay between nitric oxide (NO) and reactive oxygen species can lead to an induction of cell death in plants. The aim of our work was to find out if cyanide released from sodium nitroprusside (SNP; a donor of NO) could be involved in the cell death induction, which is triggered by SNP and H 2 O 2 . Cell suspension of Nicotiana tabacum L. (line BY-2) was treated with 0.5 mM SNP, 0.5 mM potassium ferricyanide (PFC; analogue of sodium nitroprusside which can not release NO) and/or by 0.5 mM glucose with 0.5 U cm -3 glucose oxidase (GGO; a donor system of H 2 O 2 ). The cell death was induced only by combination of SNP and GGO. Thus cyanide released was not involved in the induction of cell death. However, SNP showed toxic effect because of decrease in activities of intracellular oxidoreductases and esterases. The cell death caused by SNP and GGO occurred within 12 h. During cell death either length or width of the cell increased. Central vacuole was formed in 20 to 40 % of cells. Most of the dead cells showed a condensed cytoplasm. Two hallmarks of programmed cell death (PCD), chromatin condensation and blebbing of nuclear periphery, were observed. However, oligonucleosomal fragmentation of DNA, another hallmark of PCD, was not detected.Additional key words: Nicotiana tabacum, nitric oxide, potassium ferricyanide, programmed cell death.

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“…These include the alternative oxidases (AOX) and the NADH dehydrogenases of the Ndi and Nde families. Together these enzymes provide an alternative respiratory chain that potentially allows the maintenance of redox homeostasis and intermediary metabolism under conditions where flux through the "standard" respiratory chain is limited by high ATP levels, the action of toxins or other physiological restraints (6,7). AOX acts as a bypass of complexes III and IV, whereas Nde or Ndi can bypass complex I.…”

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confidence: 99%

Expression of the yeast NADH dehydrogenase Ndi1 in Drosophila confers increased lifespan independently of dietary restriction

Sanz

Soikkeli²,

Portero‐Otín³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

121

162

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Mutations in mitochondrial oxidative phosphorylation complex I are associated with multiple pathologies, and complex I has been proposed as a crucial regulator of animal longevity. In yeast, the single-subunit NADH dehydrogenase Ndi1 serves as a non-proton-translocating alternative enzyme that replaces complex I, bringing about the reoxidation of intramitochondrial NADH. We have created transgenic strains of Drosophila that express yeast NDI1 ubiquitously. Mitochondrial extracts from NDI1-expressing flies displayed a rotenone-insensitive NADH dehydrogenase activity, and functionality of the enzyme in vivo was confirmed by the rescue of lethality resulting from RNAi knockdown of complex I. NDI1 expression increased median, mean, and maximum lifespan independently of dietary restriction, and with no change in sirtuin activity. NDI1 expression mitigated the aging associated decline in respiratory capacity and the accompanying increase in mitochondrial reactive oxygen species production, and resulted in decreased accumulation of markers of oxidative damage in aged flies. Our results support a central role of mitochondrial oxidative phosphorylation complex I in influencing longevity via oxidative stress, independently of pathways connected to nutrition and growth signaling.aging | mitochondria | respiratory chain | free radicals M itochondria are key metabolic organelles whose oxidative phosphorylation (OXPHOS) system is considered to be one of the most efficient producers of bioenergy. When OX-PHOS function is compromized (e.g., by mutations or toxins), bioenergy supply and cellular homeostasis are seriously disrupted, which can be lethal.OXPHOS complex I plays a central role in the regulation of ATP production, intermediary metabolism, and apoptosis (1, 2), and mutations affecting it cause many human pathologies (3). It has also been proposed as a pacemaker of the aging process (4). Treatments inferred to decrease the production of reactive oxygen species (ROS) at the level of complex I can prolong lifespan in Drosophila (5). All these characteristics make it essential to understand better the role of complex I in vivo and its involvement in aging.Many organisms possess alternative enzymes that can bypass or replace the proton-translocating complexes of the mitochondrial respiratory chain. These include the alternative oxidases (AOX) and the NADH dehydrogenases of the Ndi and Nde families. Together these enzymes provide an alternative respiratory chain that potentially allows the maintenance of redox homeostasis and intermediary metabolism under conditions where flux through the "standard" respiratory chain is limited by high ATP levels, the action of toxins or other physiological restraints (6, 7). AOX acts as a bypass of complexes III and IV, whereas Nde or Ndi can bypass complex I.In previous studies these bypass enzymes were shown to be active when introduced into the mitochondria of higher metazoans such as mammals (8-12), arthropods (13), or nematodes (14), all of which lack endogenous alternative enzymes. Fu...

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Plant Uncoupling Mitochondrial Protein and Alternative Oxidase: Energy Metabolism and Stress

Cited by 53 publications

References 137 publications

Involvement of an Alternative Oxidase in Oxidative Stress and Mycelium-to-Yeast Differentiation in Paracoccidioides brasiliensis

Involvement of an Alternative Oxidase in Oxidative Stress and Mycelium-to-Yeast Differentiation in Paracoccidioides brasiliensis

Cell death induced by sodium nitroprusside and hydrogen peroxide in tobacco BY-2 cell suspension

Expression of the yeast NADH dehydrogenase Ndi1 in Drosophila confers increased lifespan independently of dietary restriction

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