Dissipation of the proton electrochemical gradient in chloroplasts promotes the oxidation of ATP synthase by thioredoxin-like proteins

Sekiguchi, Takatoshi; Yoshida, Keisuke; Wakabayashi, Keiji; Hisabori, Toru

doi:10.1016/j.jbc.2022.102541

Cited by 6 publications

(4 citation statements)

References 57 publications

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“…CDSP32/Trx L1 mediates electron transfer from Fd to 2CP in chloroplasts, playing a role in assisting 2CP to clear H 2 O 2 (Broin & Rey, 2003). Recently, it has been shown that Trx f and two types of Trx‐like proteins, Trx‐L2 and ACHT (atypical Cys‐His‐rich Trx), are involved in the oxidation of different Trx‐targeted proteins, such as glyco‐1, 6‐diphosphatase, Rubisco activase, and the γ subunit of ATP synthase (Sekiguchi et al, 2022; Yokochi et al, 2021). In contrast to the FTR‐Trx system, NTRC appears to function primarily in the dark or under limited light, possibly because it derives its reducing potential from NADPH, which can be produced independently of photosynthesis through the pentose phosphate oxidation pathway (Carrillo et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

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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Section: Discussionmentioning

confidence: 99%

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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“…Additionally, previous studies suggest that the affinity between Trx and the γ subunit has a direct connection with the proton electrochemical potential across the thylakoid membrane (∆µH + ). ∆µH + likely induces conformational changes in the γ subunit, increasing the affinity of Trx to the γ subunit and promoting Trx-induced oxidation or reduction of the γ subunit [85,86].…”

Section: Redox Reaction Of the γ Subunitmentioning

confidence: 99%

“…Under dim-light conditions, nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) serves as an electron donor for Trx, mediated by NADPH-Trx reductase (NTrxR) [84]. Under dark conditions, the oxidation of the γ subunit is mediated by two Cys-containing proteins, Trx-like protein 2 (TrxL2) and noncanonical Trx (NCTrx, rich in histidine and Cys) [85]. Additionally, previous studies suggest that the affinity between Trx and the γ subunit has a direct connection with the proton electrochemical potential across the thylakoid membrane (ΔµH + ).…”

Section: Redox Reaction Of the γ Subunitmentioning

confidence: 99%

Structure, Regulation, and Significance of Cyanobacterial and Chloroplast Adenosine Triphosphate Synthase in the Adaptability of Oxygenic Photosynthetic Organisms

Yi,

Guo,

Lou

et al. 2024

Microorganisms

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In cyanobacteria and chloroplasts (in algae and plants), ATP synthase plays a pivotal role as a photosynthetic membrane complex responsible for producing ATP from adenosine diphosphate and inorganic phosphate, utilizing a proton motive force gradient induced by photosynthesis. These two ATP synthases exhibit similarities in gene organization, amino acid sequences of subunits, structure, and functional mechanisms, suggesting that cyanobacterial ATP synthase is probably the evolutionary precursor to chloroplast ATP synthase. In this review, we explore the precise synthesis and assembly of ATP synthase subunits to address the uneven stoichiometry within the complex during transcription, translation, and assembly processes. We also compare the regulatory strategies governing ATP synthase activity to meet varying energy demands in cyanobacteria and chloroplasts amid fluctuating natural environments. Furthermore, we delve into the role of ATP synthase in stress tolerance and photosynthetic carbon fixation efficiency in oxygenic photosynthetic organisms (OPsOs), along with the current researches on modifying ATP synthase to enhance carbon fixation efficiency under stress conditions. This review aims to offer theoretical insights and serve as a reference for understanding the functional mechanisms of ATP synthase, sparking innovative ideas for enhancing photosynthetic carbon fixation efficiency by utilizing ATP synthase as an effective module in OPsOs.

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“…This pathway is important not only for downregulating the Calvin–Benson cycle and ATP synthase ( Yoshida et al. 2018 , Sekiguchi et al. 2022 ) but also for upregulating OPPP and chloroplast glycolysis, which may be helpful for flexibly switching light/dark metabolism in the chloroplasts ( Yoshida et al.…”

Section: Identification Of Protein-oxidation Pathwaysmentioning

confidence: 99%

Current Insights into the Redox Regulation Network in Plant Chloroplasts

Yoshida

Hisabori

2023

Plant and Cell Physiology

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Thiol/disulfide-based redox regulation is a ubiquitous post-translational protein modification. In plant chloroplasts, this regulatory mechanism is tightly associated with the light-dependent activation of photosynthetic enzymes (e.g., Calvin–Benson cycle enzymes). A thioredoxin (Trx)-mediated pathway was discovered to transmit light signals as a reducing power about half a century ago; since then, it has been accepted as the basic machinery of chloroplast redox regulation. However, during the past two decades, it has been increasingly apparent that plants have acquired multiple Trx isoforms and Trx-like proteins in chloroplasts. Furthermore, proteomics-based analyses have identified various chloroplast enzymes as potential targets of redox regulation. These facts highlight the necessity to revisit the molecular basis and physiological importance of the redox regulation system in chloroplasts. Recent studies have revealed novel aspects of this system, including unprecedented redox-regulated processes in chloroplasts and the functional diversity of Trx family proteins. Of particular significance is the identification of protein-oxidizing pathways that turn off photosynthetic metabolism during light-to-dark transitions. In this review, we summarize current insights into the redox regulation network in chloroplasts.

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Dissipation of the proton electrochemical gradient in chloroplasts promotes the oxidation of ATP synthase by thioredoxin-like proteins

Cited by 6 publications

References 57 publications

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

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

Structure, Regulation, and Significance of Cyanobacterial and Chloroplast Adenosine Triphosphate Synthase in the Adaptability of Oxygenic Photosynthetic Organisms

Current Insights into the Redox Regulation Network in Plant Chloroplasts

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