Thioredoxin targets of developing wheat seeds identified by complementary proteomic approaches

Wong, Joshua; Cai, Nick; Balmer, Yves; Tanaka, Charlene K.; Vensel, William H.; Hurkman, William J.; Buchanan, Bob B.

doi:10.1016/j.phytochem.2004.05.010

Cited by 150 publications

(161 citation statements)

References 39 publications

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“…Comparison of the 29 previously reported Trx target proteins identified in isolated amyloplasts (Table 2) with recent proteomic studies reveals that 10 were identified in the related chloroplast organelle (1,5), and 3 were identified in the parent endosperm fraction (3,7,8). The remaining 16 were identified in other plant systems (10).…”

Section: Identification Of Members Of the Ferredoxin͞trx System And Smentioning

confidence: 84%

“…Isolation of potential Trx target proteins using fluorescence labeling was achieved with monobromobimane (6,8). Soluble amyloplast proteins were incubated with a mixture of 10 mM iodoacetamide and 10 mM N-ethylmaleimide for 20 min at 25°C to block free thiol groups (6,61).…”

Section: Methodsmentioning

confidence: 99%

“…After a 20-min incubation, 2 mM monobromobimane was added to the reduced sample and a nonreduced (control) sample. The fluorescence was recorded after a parallel separation of the two samples by 2D gel electrophoresis (8).…”

Section: Methodsmentioning

confidence: 99%

“…The finding of a complete ferredoxin͞Trx system prompted us to look for Trx-regulated proteins in amyloplasts. To this end, we applied recently devised proteomic approaches based on fluorescent labeling (2,8) and affinity chromatography (1,5). As observed previously (8), the two techniques were complementary.…”

Section: Identification Of Members Of the Ferredoxin͞trx System And Smentioning

confidence: 99%

“…Recent approaches make it possible to identify proteins linked to Trx by combining proteomics with affinity chromatography (1) or thiol probes (2)(3)(4). These capabilities have defined an extended role of Trx in chloroplasts (1,5) and helped elucidate its function in other plant systems: mitochondria (6), seeds (2,3,7,8), and seedlings (4,9). Currently almost 200 proteins appear to be linked to Trx in plants (10).…”

mentioning

confidence: 99%

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A complete ferredoxin/thioredoxin system regulates fundamental processes in amyloplasts

Balmer

Vensel

Cai

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

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158

133

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A growing number of processes throughout biology are regulated by redox via thiol-disulfide exchange. This mechanism is particularly widespread in plants, where almost 200 proteins have been linked to thioredoxin (Trx), a widely distributed small regulatory disulfide protein. The current study extends regulation by Trx to amyloplasts, organelles prevalent in heterotrophic plant tissues that, among other biosynthetic activities, catalyze the synthesis and storage of copious amounts of starch. Using proteomics and immunological methods, we identified the components of the ferredoxin͞Trx system (ferredoxin, ferredoxin-Trx reductase, and Trx), originally described for chloroplasts, in amyloplasts isolated from wheat starchy endosperm. Ferredoxin is reduced not by light, as in chloroplasts, but by metabolically generated NADPH via ferredoxin-NADP reductase. However, once reduced, ferredoxin appears to act as established for chloroplasts, i.e., via ferredoxinTrx reductase and a Trx (m-type). A proteomics approach in combination with affinity chromatography and a fluorescent thiol probe led to the identification of 42 potential Trx target proteins, 13 not previously recognized, including a major membrane transporter (Brittle-1 or ADP-glucose transporter). The proteins function in a range of processes in addition to starch metabolism: biosynthesis of lipids, amino acids, and nucleotides; protein folding; and several miscellaneous reactions. The results suggest a mechanism whereby light is initially recognized as a thiol signal in chloroplasts, then as a sugar during transit to the sink, where it is converted again to a thiol signal. In this way, amyloplast reactions in the grain can be coordinated with photosynthesis taking place in leaves.redox regulation ͉ target proteins ͉ ferredoxin-thioredoxin reductase O ur understanding of the function of the regulatory disulfide protein thioredoxin (Trx) has increased dramatically in the past few years, with the advent of new methodologies. Recent approaches make it possible to identify proteins linked to Trx by combining proteomics with affinity chromatography (1) or thiol probes (2-4). These capabilities have defined an extended role of Trx in chloroplasts (1, 5) and helped elucidate its function in other plant systems: mitochondria (6), seeds (2,3,7,8), and seedlings (4, 9). Currently almost 200 proteins appear to be linked to Trx in plants (10). One major organelle that has been neglected, however, is the amyloplast, a plastid of heterotrophic tissues that performs a wide range of biosynthetic reactions, including the synthesis and storage of abundant quantities of starch.To help fill this gap, we have applied proteomic and immunological approaches to investigate the occurrence and function of Trx in amyloplasts. We now report evidence that amyloplasts isolated from wheat starchy endosperm resemble chloroplasts in containing a complete ferredoxin͞Trx system composed of ferredoxin, ferredoxin-Trx reductase (FTR), and Trx (m-type). Application of affinity chromatography and fl...

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Section: Identification Of Members Of the Ferredoxin͞trx System And Smentioning

confidence: 84%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Identification Of Members Of the Ferredoxin͞trx System And Smentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

A complete ferredoxin/thioredoxin system regulates fundamental processes in amyloplasts

Balmer

Vensel

Cai

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

158

133

View full text Add to dashboard Cite

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Mass Spectrometry Approaches for the Molecular Characterization of Oxidatively/Nitrosatively Modified Proteins

Scaloni

2006

Redox Proteomics

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Characterization of thiol‐based redox modifications of Brassica napusSNF1‐related protein kinase 2.6‐2C

Yoo

Zhang

et al. 2018

FEBS Open Bio

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Sucrose nonfermenting 1‐related protein kinase 2.6 (SnRK2.6), also known as Open Stomata 1 (OST1) in Arabidopsis thaliana, plays a pivotal role in abscisic acid (ABA)‐mediated stomatal closure. Four SnRK2.6 paralogs were identified in the Brassica napus genome in our previous work. Here we studied one of the paralogs, BnSnRK2.6‐2C, which was transcriptionally induced by ABA in guard cells. Recombinant BnSnRK2.6‐2C exhibited autophosphorylation activity and its phosphorylation sites were mapped. The autophosphorylation activity was inhibited by S‐nitrosoglutathione (GSNO) and by oxidized glutathione (GSSG), and the inhibition was reversed by reductants. Using monobromobimane (mBBr) labeling, we demonstrated a dose‐dependent modification of BnSnRK2.6‐2C by GSNO. Furthermore, mass spectrometry analysis revealed previously uncharacterized thiol‐based modifications including glutathionylation and sulfonic acid formation. Of the six cysteine residues in BnSnRK2.6‐2C, C159 was found to have different types of thiol modifications, suggesting its high redox sensitivity and versatility. In addition, mBBr labeling on tyrosine residues was identified. Collectively, these data provide detailed biochemical characterization of redox‐induced modifications and changes of the BnSnRK2.6‐2C activity.

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Thioredoxin targets of developing wheat seeds identified by complementary proteomic approaches

Cited by 150 publications

References 39 publications

A complete ferredoxin/thioredoxin system regulates fundamental processes in amyloplasts

A complete ferredoxin/thioredoxin system regulates fundamental processes in amyloplasts

Mass Spectrometry Approaches for the Molecular Characterization of Oxidatively/Nitrosatively Modified Proteins

Characterization of thiol‐based redox modifications of Brassica napusSNF1‐related protein kinase 2.6‐2C

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