Porin and cytochrome oxidase containing contact sites involved in the oxidation of cytosolic NADH

Piana, Gianluigi La; Marzulli, Domenico; Gorgoglione, Vincenza; Lofrumento, N.E.

doi:10.1016/j.abb.2004.12.029

Cited by 27 publications

(33 citation statements)

References 25 publications

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“…Data published in 1999 provided evidence that the activity of the NADH/cyto-c system can be modulated by increasing or decreasing the frequency of contact sites between the two mitochondrial membranes [31]. Based on previously published data [14,18,19,30,31] and that presented in this report, we maintain that the increased oxidation rate of exogenous NADH, observed in both hypotonic-and ceramide-treated mitochondria (characterized by an increase in the matrix volume), can be ascribed to an increased frequency of ''respiratory contact sites'' [14,18]. As a result of the much greater area of MIM than MOM, the increase in the matrix volume, observed in the two above mentioned conditions as well as in valinomycintreated mitochondria (Figs.…”

Section: Commentmentioning

confidence: 98%

“…Incubations were carried out at 25°C in a standard sucrose medium at pH 7.4 consisting of 220 mM sucrose, 20 mM KCl, 1 mM EDTA and 20 mM HEPES-Tris. The oxidative phosphorylation efficiency was assayed by measuring the respiratory control index expressed by the ratio state 3/state 4 respiration determined following the rate of oxygen consumption with a Clark-type electrode [14]. The values obtained were always higher than 5 with succinate and ADP and not lower than 9 with succinate ?…”

Section: Isolation and Incubation Of Mitochondriamentioning

confidence: 99%

“…We are interested in characterizing and delineating, in dissimilar metabolic states, the functional activity of the cytosolic NADH/cyto-c electron transport pathway, a system involved in the direct oxidation of NADH present outside the mitochondria [11][12][13][14]. This is a reducing equivalent transport system independent and distinct from both the shuttle system and the respiratory chain.…”

Section: Introductionmentioning

confidence: 99%

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Valinomycin induced energy-dependent mitochondrial swelling, cytochrome c release, cytosolic NADH/cytochrome c oxidation and apoptosis

et al. 2011

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In valinomycin induced stimulation of mitochondrial energy dependent reversible swelling, supported by succinate oxidation, cytochrome c (cyto-c) and sulfite oxidase (Sox) [both present in the mitochondrial intermembrane space (MIS)] are released outside. This effect can be observed at a valinomycin concentration as low as 1 nM. The rate of cytosolic NADH/cyto-c electron transport pathway is also greatly stimulated. The test on the permeability of mitochondrial outer membrane to exogenous cyto-c rules out the possibility that the increased rate of exogenous NADH oxidation could be ascribed either to extensively damaged or broken mitochondria. Accumulation of potassium inside the mitochondria, mediated by the highly specific ionophore valinomycin, promotes an increase in the volume of matrix (evidenced by swelling) and the interaction points between the two mitochondrial membranes are expected to increase. The data reported and those previously published are consistent with the view that "respiratory contact sites" are involved in the transfer of reducing equivalents from cytosol to inside the mitochondria both in the absence and the presence of valinomycin. Magnesium ions prevent at least in part the valinomycin effects. Rather than to the dissipation of membrane potential, the pro-apoptotic property of valinomycin can be ascribed to both the release of cyto-c from mitochondria to cytosol and the increased rate of cytosolic NADH coupled with an increased availability of energy in the form of glycolytic ATP, useful for the correct execution of apoptotic program.

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Section: Commentmentioning

confidence: 98%

Section: Isolation and Incubation Of Mitochondriamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Valinomycin induced energy-dependent mitochondrial swelling, cytochrome c release, cytosolic NADH/cytochrome c oxidation and apoptosis

et al. 2011

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“…2). At present, we do not know whether, as in cerebellar neurons, the cyt c released in plants can work both as a ROS scavenger and as a respiratory substrate for energy production by oxidative phosphorylation (Atlante et al, 2003a(Atlante et al, , 2003bBobba et al, 2004;La Piana et al, 2005) or whether cyt c can transfer electrons from the respiratory chain to the redox enzymes that generate mitochondrial ROS as signaling molecules for apoptosis to occur (Giorgio et al, 2005). Nonetheless, this point is under investigation.…”

Section: The Role Of Ros In Cyt C Releasementioning

confidence: 99%

Cytochrome c Is Released in a Reactive Oxygen Species-Dependent Manner and Is Degraded via Caspase-Like Proteases in Tobacco Bright-Yellow 2 Cells en Route to Heat Shock-Induced Cell Death

et al. 2006

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To gain some insight into the mechanism of plant programmed cell death, certain features of cytochrome c (cyt c) release were investigated in heat-shocked tobacco (Nicotiana tabacum) Bright-Yellow 2 cells in the 2-to 6-h time range. We found that 2 h after heat shock, cyt c is released from intact mitochondria into the cytoplasm as a functionally active protein. Such a release did not occur in the presence of superoxide anion dismutase and catalase, thus showing that it depends on reactive oxygen species (ROS). Interestingly, ROS production due to xanthine plus xanthine oxidase results in cyt c release in sister control cultures. Maximal cyt c release was found 2 h after heat shock; later, activation of caspase-3-like protease was found to increase with time. Activation of this protease did not occur in the presence of ROS scavenger enzymes. The released cyt c was found to be progressively degraded in a manner prevented by either the broad-range caspase inhibitor (zVAD-fmk) or the specific inhibitor of caspase-3 (AC-DEVD-CHO), which have no effect on cyt c release. In the presence of these inhibitors, a significant increase in survival of the cells undergoing programmed cell death was found. We conclude that ROS can trigger release of cyt c, but do not cause cell death, which requires caspase-like activation.

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“…We previously found that the maximum rate of oxygen consumption of myocardial trabecula dissected from the right ventricular wall of MCT4 rats is not different from control, whereas the rate of oxygen consumption at rest is much higher than control. It is a possibility that the high rate of oxygen consumption of quiescent hypertrophied trabeculae is due to cytochrome c release because cytosolic cytochrome c can oxidize cytosolic NADH (La Piana et al, 2005). This will reduce the efficiency of metabolic recovery, i.e.…”

Section: Oxygen Consumption and Cytochrome C Releasementioning

confidence: 99%

Inadequate Myocardial Oxygen Supply/Demand in Experimental Pulmonary Hypertension

Beek-Harmsen¹,

Feenstra²,

Laarse³

2011

Pulmonary Hypertension - From Bench Research to Clinical Challenges

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Porin and cytochrome oxidase containing contact sites involved in the oxidation of cytosolic NADH

Cited by 27 publications

References 25 publications

Valinomycin induced energy-dependent mitochondrial swelling, cytochrome c release, cytosolic NADH/cytochrome c oxidation and apoptosis

Valinomycin induced energy-dependent mitochondrial swelling, cytochrome c release, cytosolic NADH/cytochrome c oxidation and apoptosis

Cytochrome c Is Released in a Reactive Oxygen Species-Dependent Manner and Is Degraded via Caspase-Like Proteases in Tobacco Bright-Yellow 2 Cells en Route to Heat Shock-Induced Cell Death

Inadequate Myocardial Oxygen Supply/Demand in Experimental Pulmonary Hypertension

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