Thioredoxin selectivity for thiol-based redox regulation of target proteins in chloroplasts.

摘要: Redox regulation based on the thioredoxin (Trx) system is believed to ensure light-responsive control of various functions in chloroplasts. Five Trx subtypes have been reported reside chloroplasts, but their functional diversity redox target proteins remains poorly clarified. To directly address this issue, we studied Trx-dependent shifts several chloroplast thiol-modulated enzymes vitro and vivo. In assays using a series Arabidopsis recombinant provided new insights into selectivity for as well underpinning previous suggestions. Most notably, by combining discrimination thiol status with mass spectrometry activity measurement, identified an uncharacterized aspect reductive activation NADP-malate dehydrogenase; two redox-active Cys pairs harbored enzyme were reduced via distinct utilization Trxs even within single polypeptide. our assays, Trx-f was effective reducing all analyzed here. We then investigated vivo physiological relevance these findings, wild-type Trx-f-deficient plants. Photoreduction fructose-1,6-bisphosphatase partially impaired plants, global impact deficiency behaviors not striking expected from data. Our results provide support functionality also highlight complexity plasticity network. Background: Thioredoxin plays pivotal role proteins. Results: Functional determined observing Conclusion: Novel network provided. Significance: shed light molecular basis adjustment functions.