Modulation of Cytochrome c-Mediated Extramitochondrial NADH Oxidation by Contact Site Density

Marzulli, Domenico; Piana, Gianluigi La; Fransvea, Emilia; Lofrumento, N.E.

doi:10.1006/bbrc.1999.0787

Cited by 25 publications

(24 citation statements)

References 22 publications

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“…It was assumed that under some conditions, when the concentration of cytoplasmic cytochrome c is increased, the external NADH oxidation by intact mitochondria might be significantly activated due to a bi-trans-membrane electron transport catalyzed by external cytochrome c (25), and it could play an essential role in mechanisms of apoptosis. However, it cannot be excluded that the stimulation of the external NADH oxidation by exogenous cytochrome c, observed by the authors (24,25), relates to only damaged mitochondria that represent nearly 10% of the total population of isolated mitochondria (11,13,14). Whatever the mechanism of rotenone-insensitive oxidation of cytoplasmic NADH, activation of this process is likely to be important in redox signaling in apoptosis.…”

Section: Resultsmentioning

confidence: 95%

“…On the other hand, the external NADH oxidation was also suggested to be realized through the contact sites between the OMM and the inner mitochondrial membrane (IMM) in the intact mitochondria (24). It was assumed that under some conditions, when the concentration of cytoplasmic cytochrome c is increased, the external NADH oxidation by intact mitochondria might be significantly activated due to a bi-trans-membrane electron transport catalyzed by external cytochrome c (25), and it could play an essential role in mechanisms of apoptosis.…”

Section: Resultsmentioning

confidence: 99%

“…These authors suggested that extramitochondrial cytochrome c, reduced on the OMM by external NADH, might be directly oxidized by cytochrome c oxidase of mitochondria, transferring electrons through the intact OMM. It was suggested that "intact (but not damaged) mitochondria are able to promote the oxidation of exogenous cytochrome c" (24). The data obtained by Bodrova et al (10) and our own results (9,11) do not support this concept, because the OMM rupture was shown to be an obligatory factor for the rotenone-insensitive oxidation of external NADH by rat liver mitochondria (9 -12).…”

mentioning

confidence: 79%

“…According to some data, the rate of external NADH oxidation by rat liver mitochondria may be stimulated by extramitochondrial cytochrome c (22). The concept of "bi-trans-membrane" electron transport was developed to explain this phenomenon (22)(23)(24), assuming its possible relation to the mechanisms of apoptosis (25). These authors suggested that extramitochondrial cytochrome c, reduced on the OMM by external NADH, might be directly oxidized by cytochrome c oxidase of mitochondria, transferring electrons through the intact OMM.…”

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confidence: 99%

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Cytochrome c Sorption-Desorption Effects on the External NADH Oxidation by Mitochondria

Lemeshko

2002

Journal of Biological Chemistry

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The rupture of the outer mitochondrial membrane is known to be critical for cell death, but the mechanism, specifically its redox-signaling aspects, still needs to be studied in more detail. In this work, the external NADH oxidation by rat liver mitochondria was studied under the outer membrane rupture induced by the mitochondria hypotonic treatment or the inner membrane permeability transition. The saturation of the oxidation rate was observed as a function of mitochondrial protein concentration. This effect was shown to result from cytochrome c binding to the mitochondrial membranes. At a relatively high concentration of mitochondria, the oxidation rate was strongly activated by 4 mM Mg 2؉ due to cytochrome c desorption from the membranes. A minimal kinetic model was developed to explain the main phenomena of the external NADH oxidation modulated by cytochrome c and Mg 2؉ in mitochondria with the ruptured outer membrane. The computational behavior of the model closely agreed with the experimental data. We suggest that the redox state of the released cytochrome c, considered by other authors to be important for apoptosis, may strongly depend on its oxidation by the fraction of mitochondria with the ruptured outer membrane and on the cytoplasmic cytochrome c reductase activity.

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Section: Resultsmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 79%

mentioning

confidence: 99%

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Cytochrome c Sorption-Desorption Effects on the External NADH Oxidation by Mitochondria

Lemeshko

2002

Journal of Biological Chemistry

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“…To get a possible answer to this, we first have to consider the physiological significance of contact sites. It has to be stressed that contact sites are dynamic structures of variable composition and serve different functions, such as protein import into mitochondria [55][56][57], translocation of phospholipids and phospholipid precursors [58][59][60][61], transport of cholesterol for steroidogenesis [62], and oxidation of cytosolic NADH [63]. Here, mitochondrial contact sites are discussed only in the context of metabolite channelling and permeability transition, where in both cases, MtCK serves a functional as well as structural role.…”

Section: Interaction Of Mtck With Outer and Inner Membrane Componentsmentioning

confidence: 99%

Mitochondrial Creatine Kinase in Contact Sites: Interaction with Porin and Adenine Nucleotide Translocase, Role in Permeability Transition and Sensitivity to Oxidative Damage

Dolder¹,

Wendt²,

Wallimann³

2001

Biol Signals Recept

109

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The creatine/phosphocreatine circuit provides an efficient energy buffering and transport system in a variety of cells with high and fluctuating energy requirements. It connects sites of energy production (mitochondria, glycolysis) with sites of energy consumption (various cellular ATPases). The cellular creatine/phosphocreatine pool is linked to the ATP/ADP pool by the action of different isoforms of creatine kinase located at distinct subcellular compartments. Octameric mitochondrial creatine kinase (MtCK), together with porin and adenine nucleotide translocase, forms a microcompartment at contact sites between inner and outer mitochondrial membranes and facilitates the production and export into the cytosol of phosphocreatine. MtCK is probably in direct protein-protein contact with outer membrane porin, whereas interaction with inner membrane adenine nucleotide translocase is rather mediated by acidic phopholipids (like cardiolipin) present in significant amounts in the inner membrane. Octamer-dimer transitions of MtCK as well as different creatine kinase substrates have a profound influence on controlling mitochondrial permeability transition (MPT). Inactivation by reactive oxygen species of MtCK and destabilization of its octameric structure are factors that contribute to impairment of energy homeostasis and facilitated opening of the MPT pore, which eventually lead to tissue damage during periods of ischemia/reperfusion.

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Mitochondrial VDAC and Its Complexes

Brdiczka

2007

Molecular System Bioenergetics

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Modulation of Cytochrome c-Mediated Extramitochondrial NADH Oxidation by Contact Site Density

Cited by 25 publications

References 22 publications

Cytochrome c Sorption-Desorption Effects on the External NADH Oxidation by Mitochondria

Cytochrome c Sorption-Desorption Effects on the External NADH Oxidation by Mitochondria

Mitochondrial Creatine Kinase in Contact Sites: Interaction with Porin and Adenine Nucleotide Translocase, Role in Permeability Transition and Sensitivity to Oxidative Damage

Mitochondrial VDAC and Its Complexes

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