Regulation of oxidative phosphorylation in plant mitochondria

Diolez, Philippe; Kesseler, A; Haraux, Francis; Valerio, Marie; Brinkmann, Klaus; Brand, Martin D.

doi:10.1042/bst0210769

Cited by 18 publications

(6 citation statements)

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“…Metabolic control measurements on isolated mitochondriaalso suggest that as the rate of flux increases towards the maximumpossible flux, i.e. state 3, the degree of control exerted by thephosphorylation reactions decreases, whereas control exerted bythe respiratory chain increases (Diolez et al .1993). Therefore, as temperature causes an increase in fluxthrough the pathway it is possible that adenylate control decreasesdue to a decrease in the proportion of control exerted by the phosphorylationreactions.…”

Section: Discussionmentioning

confidence: 99%

Regulation of root respiration in two species of Plantago that differ in relative growth rate: the effect of short‐ and long‐term changes in temperature

Covey-Crump

Attwood

Atkin

2002

Plant Cell & Environment

100

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This study investigates the effect of short-and long-term changes in temperature on the regulation of root respiratory O 2 uptake by substrate supply, adenylate restriction and/or the capacity of the respiratory system. The species investigated were the lowland Plantago lanceolata L. and alpine Plantago euryphylla Briggs , Carolin & Pulley, which are inherently fast-and slow-growing, respectively. The plants were grown hydroponically in a controlled environment (constant 23 ∞ ∞ ∞ ∞ C). The effect of long-term exposure to low temperature on regulation of respiration was also assessed in P. lanceolata using plants transferred to 15/ 10 ∞ ∞ ∞ ∞ C (day/night) for 7 d. Exogenous glucose and uncoupler (CCCP) were used to assess the extent to which respiration rates were limited by substrate supply and adenylates. The results suggest that adenylates and/or substrate supply exert the greatest control over respiration at moderate temperatures (e.g. 15-30 ∞ ∞ ∞ ∞ C) in both species. At low temperatures (5-15 ∞ ∞ ∞ ∞ C), CCCP and glucose had little effect on respiration, suggesting that respiration was limited by enzyme capacity alone. The Q 10 (proportional increase of respiration per 10 ∞ ∞ ∞ ∞ C) of respiration was increased following the addition of CCCP and/or exogenous glucose. The degree of stimulation by CCCP was considerably lower in P. euryphylla than P. lanceolata . This suggests that respiration rates operate much closer to the maximum capacity in P. euryphylla than P. lanceolata . When P. lanceolata was transferred to 15 ∞ ∞ ∞ ∞ C for 7 d, respiration acclimated to the lower growth temperature (as demonstrated by an increase in respiration rates measured at 25 ∞ ∞ ∞ ∞ C). In addition, the Q 10 was higher, and the stimulatory effect of exogenous glucose and CCCP lower, in the cold-acclimated roots in comparison with their warm-grown counterparts. Acclimation of P. lanceolata to different day/night-time temperature regimes was also investigated. The low nighttime temperature was found to be the most important factor influencing acclimation. The Q 10 values were also higher in plants exposed to the lowest night-time temperature. The results demonstrate that short-and long-term changes in temperature alter the importance of substrate supply, adenylates and capacity of respiratory enzymes in regulating respiratory flux.

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Section: Discussionmentioning

confidence: 99%

Regulation of root respiration in two species of Plantago that differ in relative growth rate: the effect of short‐ and long‐term changes in temperature

Covey-Crump

Attwood

Atkin

2002

Plant Cell & Environment

100

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“…The most interesting results concerning mitochondria presented here were collected from the top-down analysis of mitochondrial function [24,36]. Top-down analysis has already been used by different groups to study the effect of complex effectors on oxidative phosphorylation, as it gives an overview of the functioning of the integrated system and helps in the detection of dysfunctions [27,29,[37][38][39][40].…”

Section: Discussionmentioning

confidence: 99%

Mitochondrial permeability transition during hypothermic to normothermic reperfusion in rat liver demonstrated by the protective effect of cyclosporin A

Leducq

Delmas-Beauvieux

Bourdel-Marchasson

et al. 1998

Biochemical Journal

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The purpose of this study was to test the hypothesis that mitochondrial permeability transition might be implicated in mitochondrial and intact organ dysfunctions associated with damage induced by reperfusion after cold ischaemia. Energetic metabolism was assessed continuously by 31P-NMR on a model system of isolated perfused rat liver; mitochondria were extracted from the livers and studied by using top-down control analysis. During the temperature transition from hypothermic to normothermic perfusion (from 4 to 37 degrees C) the ATP content of the perfused organ fell rapidly, and top-down metabolic control analysis of damaged mitochondria revealed a specific control pattern characterized by a dysfunction of the phosphorylation subsystem leading to a decreased response to cellular ATP demand. Both dysfunctions were fully prevented by cyclosporin A, a specific inhibitor of the mitochondrial transition pore (MTP). These results strongly suggest the involvement of the opening of MTP in vivo during the transition to normothermia on rat liver mitochondrial function and organ energetics.

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“…This approach groups the system into two or three subsystems of reactions connected by a common intermediate [10]. It was first applied to determine the control of oxidative phosphorylation in animal [7,8,11,12] or plant mitochondria [13,14] under variable phosphorylating conditions. In those studies, the kinetic responses of substrate oxidation, the phosphorylation reactions and proton leakage to their common intermediate (the protonmotive force, ∆p) were measured under different ATP turnover conditions.…”

Section: Introductionmentioning

confidence: 99%

Top-down control analysis of temperature effect on oxidative phosphorylation

Dufour

Rousse

Canioni

et al. 1996

Biochemical Journal

101

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The effects of temperature on the control of respiration rate, phosphorylation rate, proton leakage rate, the protonmotive force and the effective ATP/O ratio were determined in isolated rat liver mitochondria over a range of respiratory conditions by applying top-down elasticity and control analyses. Simultaneous measurements of membrane potential, oxidation and phosphorylation rates were performed under various ATP turnover rates, ranging from state 4 to state 3. Although the activities of the three subsystems decreased with temperature (over 30-fold between 37 and 4 degrees C), the effective ATP/O ratio exhibited a maximum at 25 degrees C, far below the physiological value. Top-down elasticity analysis revealed that maximal membrane potential was maintained over the range of temperature studied, and that the proton leakage rate was considerably reduced at 4 degrees C. These results definitely rule out a possible uncoupling of mitochondria at low temperature. At 4 degrees C, the decrease in ATP/O ratio is explained by the relative decrease in phosphorylation processes revealed by the decrease in depolarization after ADP addition [Diolez and Moreau (1985) Biochim. Biophys. Acta 806, 56-63]. The change in depolarization between 37 and 25 degrees C was too small to explain the decrease in ATP/O ratio. This result is best explained by the changes in the elasticity of proton leakage to membrane potential between 37 and 25 degrees C, leading to a higher leak rate at 37 degrees C for the same value of membrane potential. Top-down control analysis showed that despite the important changes in activities of the three subsystems between 37 and 25 degrees C, the patterns of the control distribution are very similar. However, a different pattern was obtained at 4 degrees C under all phosphorylating conditions. Surprisingly, control by the proton leakage subsystem was almost unchanged, although both control patterns by substrate oxidation and phosphorylation subsystems were affected at 4 degrees C. In comparison with results for 25 and 37 degrees C, at 4 degrees C there was evidence for increased control by the phosphorylation subsystem over both fluxes of oxidation and phosphorylation as well as on the ATP/O ratio when the system is close to state 3. However, the pattern of control coefficients as a function of mitochondrial activity also showed enhanced control exerted by the substrate oxidation subsystem under all intermediate conditions. These results suggest that passive membrane permeability to protons is not involved in the effect of temperature on the control of oxidative phosphorylation.

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Regulation of oxidative phosphorylation in plant mitochondria

Cited by 18 publications

References 0 publications

Regulation of root respiration in two species of Plantago that differ in relative growth rate: the effect of short‐ and long‐term changes in temperature

Regulation of root respiration in two species of Plantago that differ in relative growth rate: the effect of short‐ and long‐term changes in temperature

Mitochondrial permeability transition during hypothermic to normothermic reperfusion in rat liver demonstrated by the protective effect of cyclosporin A

Top-down control analysis of temperature effect on oxidative phosphorylation

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