The chloroplast 2-cysteine peroxiredoxin functions as thioredoxin oxidase in redox regulation of chloroplast metabolism

Vaseghi, Mohamad-Javad; Chibani, Kamel; Telman, Wilena; Liebthal, Michael; Gerken, Melanie; Schnitzer, Helena; Mueller, Sara Mareike; Dietz, Karl‐Josef

doi:10.7554/elife.38194

Cited by 118 publications

(118 citation statements)

References 63 publications

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“…FDX functions as hub for electron distribution at the donor site of photosystem I. The first mathematical model aimed to simulate electron distribution from TRX-f1 to FBPase and 2CysPRX in dependence on the H 2 O 2 concentration ( Fig 1A) and was built on the model presented by Vaseghi et al [12] which was expanded by including H 2 O 2 and reversibility of the reactions in Eqs 1 and 2. The question asked concerned the efficiency of oxidized 2CysPRX to compete with reduction of TRX-f1 by FDX-dependent TRX reductase (FTR).…”

Section: Resultsmentioning

confidence: 99%

“…Starting values of FTR and TRX-f1 were set to 80% reduced and 20% oxidized. 2CysPRX start values for reduced and oxidized form were 35% and 65% [12]. (B-E) Redox states of the network components FTR, TRX-f1, 2CysPRX and FBPase at varying H 2 O 2 concentrations as obtained after 3h of simulation in the presence of H 2 O 2 ranging between 0 and 10 μM.…”

Section: Fig 1 Simulated Redox State Of Ftr-network Components In Dementioning

confidence: 99%

“…Initial values of FNR red and FNR semired were set to 40%. All other oxidized forms were initially set to 20% apart from 2CysPRX at the starting point with 65% in the oxidized form [12]. The NADPH/NADP + couple was full reduced at t = 0.…”

Section: Fig 1 Simulated Redox State Of Ftr-network Components In Dementioning

confidence: 99%

“…This situation changes in darkness were the rate through the PET-driven FDX/TRX-pathway mostly ceases, or at lowered photosynthetic active radiation where intermediate flux conditions are established. This balance between oxidation and reduction is suggested to determine the rate of, e.g., the CBB [12].…”

Section: Introductionmentioning

confidence: 99%

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Computational simulation of the reactive oxygen species and redox network in the regulation of chloroplast metabolism

et al. 2020

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Cells contain a thiol redox regulatory network to coordinate metabolic and developmental activities with exogenous and endogenous cues. This network controls the redox state and activity of many target proteins. Electrons are fed into the network from metabolism and reach the target proteins via redox transmitters such as thioredoxin (TRX) and NADPHdependent thioredoxin reductases (NTR). Electrons are drained from the network by reactive oxygen species (ROS) through thiol peroxidases, e.g., peroxiredoxins (PRX). Mathematical modeling promises access to quantitative understanding of the network function and was implemented by using published kinetic parameters combined with fitting to known biochemical data. Two networks were assembled, namely the ferredoxin (FDX), FDX-dependent TRX reductase (FTR), TRX, fructose-1,6-bisphosphatase (FBPase) pathway with 2cysteine PRX/ROS as oxidant, and separately the FDX, FDX-dependent NADP reductase (FNR), NADPH, NTRC-pathway for 2-CysPRX reduction. Combining both modules allowed drawing several important conclusions of network performance. The resting H 2 O 2 concentration was estimated to be about 30 nM in the chloroplast stroma. The electron flow to metabolism exceeds that into thiol regulation of FBPase more than 7000-fold under physiological conditions. The electron flow from NTRC to 2-CysPRX is about 5.32-times more efficient than that from TRX-f1 to 2-CysPRX. Under severe stress (30 μM H 2 O 2) the ratio of electron flow to the thiol network relative to metabolism sinks to 1:251 whereas the ratio of eflow from NTRC to 2-CysPRX and TRX-f1 to 2-CysPRX rises up to 1:67. Thus, the simulation provides clues on experimentally inaccessible parameters and describes the functional state of the chloroplast thiol regulatory network.

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Section: Resultsmentioning

confidence: 99%

Section: Fig 1 Simulated Redox State Of Ftr-network Components In Dementioning

confidence: 99%

Section: Fig 1 Simulated Redox State Of Ftr-network Components In Dementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Computational simulation of the reactive oxygen species and redox network in the regulation of chloroplast metabolism

et al. 2020

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“…Compared to U, FL with the same average intensity often reduces plant growth [7][8][9][10], although exceptions exist [11]. There are at least two reasons for this reduction.…”

Section: Introductionmentioning

confidence: 99%

Growth under Fluctuating Light Reveals Large Trait Variation in a Panel of Arabidopsis Accessions

Kaiser

Walther

Armbruster

2020

Plants

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The capacity of photoautotrophs to fix carbon depends on the efficiency of the conversion of light energy into chemical potential by photosynthesis. In nature, light input into photosynthesis can change very rapidly and dramatically. To analyze how genetic variation in Arabidopsis thaliana affects photosynthesis and growth under dynamic light conditions, 36 randomly chosen natural accessions were grown under uniform and fluctuating light intensities. After 14 days of growth under uniform or fluctuating light regimes, maximum photosystem II quantum efficiency (Fv/Fm) was determined, photosystem II operating efficiency (ΦPSII) and non-photochemical quenching (NPQ) were measured in low light, and projected leaf area (PLA) as well as the number of visible leaves were estimated. Our data show that ΦPSII and PLA were decreased and NPQ was increased, while Fv/Fm and number of visible leaves were unaffected, in most accessions grown under fluctuating compared to uniform light. There were large changes between accessions for most of these parameters, which, however, were not correlated with genomic variation. Fast growing accessions under uniform light showed the largest growth reductions under fluctuating light, which correlated strongly with a reduction in ΦPSII, suggesting that, under fluctuating light, photosynthesis controls growth and not vice versa.

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CBSX2 is required for the efficient oxidation of chloroplast redox‐regulated enzymes in darkness

Li,

Zhang,

Shen

et al. 2023

Plant Direct

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Thiol/disulfide‐based redox regulation in plant chloroplasts is essential for controlling the activity of target proteins in response to light signals. One of the examples of such a role in chloroplasts is the activity of the chloroplast ATP synthase (CFoCF1), which is regulated by the redox state of the CF1γ subunit and involves two cysteines in its central domain. To investigate the mechanism underlying the oxidation of CF1γ and other chloroplast redox‐regulated enzymes in the dark, we characterized the Arabidopsis cbsx2 mutant, which was isolated based on its altered NPQ (non‐photochemical quenching) induction upon illumination. Whereas in dark‐adapted WT plants CF1γ was completely oxidized, a small amount of CF1γ remained in the reduced state in cbsx2 under the same conditions. In this mutant, reduction of CF1γ was not affected in the light, but its oxidation was less efficient during a transition from light to darkness. The redox states of the Calvin cycle enzymes FBPase and SBPase in cbsx2 were similar to those of CF1γ during light/dark transitions. Affinity purification and subsequent analysis by mass spectrometry showed that the components of the ferredoxin‐thioredoxin reductase/thioredoxin (FTR‐Trx) and NADPH‐dependent thioredoxin reductase (NTRC) systems as well as several 2‐Cys peroxiredoxins (Prxs) can be co‐purified with CBSX2. In addition to the thioredoxins, yeast two‐hybrid analysis showed that CBSX2 also interacts with NTRC. Taken together, our results suggest that CBSX2 participates in the oxidation of the chloroplast redox‐regulated enzymes in darkness, probably through regulation of the activity of chloroplast redox systems in vivo.

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The chloroplast 2-cysteine peroxiredoxin functions as thioredoxin oxidase in redox regulation of chloroplast metabolism

Cited by 118 publications

References 63 publications

Computational simulation of the reactive oxygen species and redox network in the regulation of chloroplast metabolism

Computational simulation of the reactive oxygen species and redox network in the regulation of chloroplast metabolism

Growth under Fluctuating Light Reveals Large Trait Variation in a Panel of Arabidopsis Accessions

CBSX2 is required for the efficient oxidation of chloroplast redox‐regulated enzymes in darkness

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