Membrane-Bound NAD(P)H Dehydrogenases in Higher Plant Cells

Møller, Ian Max; Lin, Willy

doi:10.1146/annurev.pp.37.060186.001521

Cited by 222 publications

(103 citation statements)

References 46 publications

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“…In plants, there are no studies concerning the influence of Cr(VI) on mitochondrial bioenergetics. Higher plant mitochondria are similar to animal counterparts in several aspects, yet they possess unique feactures, namely, the presence of specific NAD(P)H dehydrogenases, the size and complexity of DNA, higher rates of O 2 consumption, oxidation of fatty acids, and an alternative oxidase [31,32].…”

Section: Introductionmentioning

confidence: 99%

Chromium(VI) interaction with plant and animal mitochondrial bioenergetics: A comparative study

Férnandes

Santos

Alpoím

et al. 2002

J Biochem & Molecular Tox

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The mechanism of Cr(VI)-induced toxicity in plants and animals has been assessed for mitochondrial bioenergetics and membrane damage in turnip root and rat liver mitochondria. By using succinate as the respiratory substrate, ADP/O and respiratory control ratio (RCR) were depressed as a function of Cr(VI) concentration. State 3 and uncoupled respiration were also depressed by Cr(VI). Rat mitochondria revealed a higher sensitivity to Cr(VI), as compared to turnip mitochondria. Rat mitochondrial state 4 respiration rate triplicated in contrast to negligible stimulation of turnip state 4 respiration. Chromium(VI) inhibited the activity of the NADH-ubiquinone oxidoreductase (complex I) from rat liver mitochondria and succinatedehydrogenases (complex II) from plant and animal mitochondria. In rat liver mitochondria, complex I was more sensitive to Cr(VI) than complex II. The activity of cytochrome c oxidase (complex IV) was not sensitive to Cr(VI). Unique for plant mitochondria, exogenous NADH uncoupled respiration was unaffected by Cr(VI), indicating that the NADH dehydrogenase of the outer leaflet of the plant inner membrane, in addition to complexes III and IV, were insensitive to Cr(VI). The ATPase activity (complex V) was stimulated in rat liver mitochondria, but inhibited in turnip root mitochondria. In both, turnip and rat mitochondria, Cr(VI) depressed mitochondrial succinate-dependent transmembrane potential (∆ψ) and phosphorylation efficiency, but it neither affected mitochondrial membrane permeabilization to protons (H + ) nor induced membrane lipid peroxidation. However, Cr(VI) induced mitochondrial membrane permeabilization to K + , an effect that was more pronounced in turnip root than in rat liver mitochondria. In conclusion, Cr(VI)-induced perturbations of mitochondrial bioenergetics compromises energy-dependent biochemical processes and, therefore, may contribute to the basal mechanism underlying its toxic effects in plant and animal cells.

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Section: Introductionmentioning

confidence: 99%

Chromium(VI) interaction with plant and animal mitochondrial bioenergetics: A comparative study

Férnandes

Santos

Alpoím

et al. 2002

J Biochem & Molecular Tox

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“…The resulting electrons enter he electron transport chain at ubiquinone bypassing Complex i, the site of rotenone inhibition [1][2][3][4][5]. Compared to NADH ~xidation, NADPH oxidation has a lower pH optimum [6][7][8], s more sensitive to thiol reagents [7,9] and appears to require nore Ca 2÷ for activity [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

“…Likewise, mitochondria rom suspension-cultured cells of sugar beet oxidize NADH, ~ut exhibit very low rates of NADPH oxidation [14]. On the )asis of this circumstantial evidence it has been concluded that t is most likely that two separate enzymes exist, one for each ,:oenzyme [2,4,14]. However, no direct evidence has ever been r~resented to support this conclusion.…”

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confidence: 99%

Direct evidence for the presence of two external NAD(P)H dehydrogenases coupled to the electron transport chain in plant mitochondria

1995

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Exogenous NADPH oxidation by purified mitochondria from both potato tuber and Arum maculatum spadix was completely and irreversibly inhibited by sub-micromolar diphen~leneiodonium (DPI), while exogenous NADH oxidation was inhibited to only a small degree. Addition of DPI caused the collapse of the membrane potential generated by NADPH oxidation, while the potential generated by NADH was unaffected. We conclude that there are two distinct enzymes on the outer surface of the inner membrane of plant mitochondria, one specific for NADH, the other relatively specific for NADPH, with both enzymes linked to the electron transport chain.Key words: Diphenyleneiodonium; Electron transport chain; Mitochondria, plant; NAD(P)H dehydrogenase |. IntroductionUnlike mammalian mitochondria, the electron transport hain of plant mitochondria contains at least two NAD(P)H ,tehydrogenases in addition to Complex I [1]. One of these ~otenone-insensitive dehydrogenases is located on the outer , urface of the inner mitochondrial membrane, the other on the inner, matrix surface, and in the following we will refer to them ;s NDex and NDin, respectively.Due to the presence of NDex, plant mitochondria oxidize ~xogenous NADH and NADPH. The resulting electrons enter he electron transport chain at ubiquinone bypassing Complex i, the site of rotenone inhibition [1][2][3][4][5]. Compared to NADH ~xidation, NADPH oxidation has a lower pH optimum [6][7][8], s more sensitive to thiol reagents [7,9] and appears to require nore Ca 2÷ for activity [9][10][11][12]. NADH oxidation has been re~orted to be induced in red beetroots without a concomitant nduction of NADPH oxidation [13]. Likewise, mitochondria rom suspension-cultured cells of sugar beet oxidize NADH, ~ut exhibit very low rates of NADPH oxidation [14]. On the )asis of this circumstantial evidence it has been concluded that t is most likely that two separate enzymes exist, one for each ,:oenzyme [2,4,14]. However, no direct evidence has ever been r~resented to support this conclusion.Diphenyleneiodonium ( Materials and methodsMitochondria were prepared from potato (Solanum tuberosum L.) tubers according to [16]. Crude mitochondria were isolated from Arum maculatum spadices according to [17] and purified according to [18].Oxygen consumption was measured in a medium containing 0.3 M sucrose, 5 mM MOPS (pH 7.2), 5 mM KH:PO4, 2.5 mM MgCI2, 1 mM CaC12 and 0.4 ¢tM FCCP using an oxygen electrode (Rank Bros.). The membrane of the oxygen electrode was washed with 70% (v/v) ethanol between assays to avoid carry-over of DPI.Membrane potential measurements using 16 ]zM safranine as the probe were made according to [19]. The medium used was the same as that above except that FCCP was omitted, CaCI2 was 0.1 mM and 20 ,ug.mg 1 BSA was included.NAD(P)H oxidation with oxygen as the electron acceptor was assayed spectrophotometrically at 340 nm in the same medium used for the oxygen electrode measurements. Activities were calculated using an extinction coefficient for NAD(P)H of 6.2 mM -1 .cm -~, All ...

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“…The correlation between the presence of LIAC and the plant PM was so high that LIAC was suggested to be one of the positive marker activities for the plant PM (Widell, Lundborg & Larsson 1982). By the end of the 1980s the presence of redox (or electron-transporting) constituents in the plant plasma membrane became well established and widely accepted (Møller & Lin 1986;Møller et al 1988;Møller & Crane 1990).…”

Section: Introductionmentioning

confidence: 99%