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Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts
Thiol-based redox regulation ensures light-responsive control of chloroplast functions. Light-derived signal is transferred in the form of reducing power from the photosynthetic electron transport chain to several redox-sensitive target proteins. Two types of protein, ferredoxin-thioredoxin reductas...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6262275/ https://www.ncbi.nlm.nih.gov/pubmed/30384474 http://dx.doi.org/10.3390/antiox7110153 |
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author | Yoshida, Keisuke Hisabori, Toru |
author_facet | Yoshida, Keisuke Hisabori, Toru |
author_sort | Yoshida, Keisuke |
collection | PubMed |
description | Thiol-based redox regulation ensures light-responsive control of chloroplast functions. Light-derived signal is transferred in the form of reducing power from the photosynthetic electron transport chain to several redox-sensitive target proteins. Two types of protein, ferredoxin-thioredoxin reductase (FTR) and thioredoxin (Trx), are well recognized as the mediators of reducing power. However, it remains unclear which step in a series of redox-relay reactions is the critical bottleneck for determining the rate of target protein reduction. To address this, the redox behaviors of FTR, Trx, and target proteins were extensively characterized in vitro and in vivo. The FTR/Trx redox cascade was reconstituted in vitro using recombinant proteins from Arabidopsis. On the basis of this assay, we found that the FTR catalytic subunit and f-type Trx are rapidly reduced after the drive of reducing power transfer, irrespective of the presence or absence of their downstream target proteins. By contrast, three target proteins, fructose 1,6-bisphosphatase (FBPase), sedoheptulose 1,7-bisphosphatase (SBPase), and Rubisco activase (RCA) showed different reduction patterns; in particular, SBPase was reduced at a low rate. The in vivo study using Arabidopsis plants showed that the Trx family is commonly and rapidly reduced upon high light irradiation, whereas FBPase, SBPase, and RCA are differentially and slowly reduced. Both of these biochemical and physiological findings suggest that reducing power transfer from Trx to its target proteins is a rate-limiting step for chloroplast redox regulation, conferring distinct light-responsive redox behaviors on each of the targets. |
format | Online Article Text |
id | pubmed-6262275 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-62622752018-11-29 Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts Yoshida, Keisuke Hisabori, Toru Antioxidants (Basel) Article Thiol-based redox regulation ensures light-responsive control of chloroplast functions. Light-derived signal is transferred in the form of reducing power from the photosynthetic electron transport chain to several redox-sensitive target proteins. Two types of protein, ferredoxin-thioredoxin reductase (FTR) and thioredoxin (Trx), are well recognized as the mediators of reducing power. However, it remains unclear which step in a series of redox-relay reactions is the critical bottleneck for determining the rate of target protein reduction. To address this, the redox behaviors of FTR, Trx, and target proteins were extensively characterized in vitro and in vivo. The FTR/Trx redox cascade was reconstituted in vitro using recombinant proteins from Arabidopsis. On the basis of this assay, we found that the FTR catalytic subunit and f-type Trx are rapidly reduced after the drive of reducing power transfer, irrespective of the presence or absence of their downstream target proteins. By contrast, three target proteins, fructose 1,6-bisphosphatase (FBPase), sedoheptulose 1,7-bisphosphatase (SBPase), and Rubisco activase (RCA) showed different reduction patterns; in particular, SBPase was reduced at a low rate. The in vivo study using Arabidopsis plants showed that the Trx family is commonly and rapidly reduced upon high light irradiation, whereas FBPase, SBPase, and RCA are differentially and slowly reduced. Both of these biochemical and physiological findings suggest that reducing power transfer from Trx to its target proteins is a rate-limiting step for chloroplast redox regulation, conferring distinct light-responsive redox behaviors on each of the targets. MDPI 2018-10-31 /pmc/articles/PMC6262275/ /pubmed/30384474 http://dx.doi.org/10.3390/antiox7110153 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Yoshida, Keisuke Hisabori, Toru Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts |
title | Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts |
title_full | Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts |
title_fullStr | Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts |
title_full_unstemmed | Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts |
title_short | Determining the Rate-Limiting Step for Light-Responsive Redox Regulation in Chloroplasts |
title_sort | determining the rate-limiting step for light-responsive redox regulation in chloroplasts |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6262275/ https://www.ncbi.nlm.nih.gov/pubmed/30384474 http://dx.doi.org/10.3390/antiox7110153 |
work_keys_str_mv | AT yoshidakeisuke determiningtheratelimitingstepforlightresponsiveredoxregulationinchloroplasts AT hisaboritoru determiningtheratelimitingstepforlightresponsiveredoxregulationinchloroplasts |