Comprehensive survey of redox sensitive starch metabolising enzymes in Arabidopsis thaliana
pmid: 22789914
Comprehensive survey of redox sensitive starch metabolising enzymes in Arabidopsis thaliana
In chloroplasts, the ferredoxin/thioredoxin pathway regulates enzyme activity in response to light by reduction of regulatory disulfides in target enzymes, ensuring coordination between photosynthesis and diurnal metabolism. Although earlier studies have suggested that many starch metabolic enzymes are similarly regulated, redox regulation has only been verified for a few of these in vitro. Using zymograms and enzyme assays, we performed a comprehensive analysis of the redox sensitivity of known starch metabolising enzymes in extracts of Arabidopsis thaliana. Manipulation of redox potentials revealed that several enzymatic activities where activated by reduction at physiologically relevant potentials. Among these where the isoamylase complex AtISA1/AtISA2, the limit dextrinase AtLDA, starch synthases AtSS1 and AtSS3, and the starch branching enzyme AtBE2. The reversibility of the redox reaction was confirmed by enzyme assays for AtLDA, AtSS1 and AtSS3. Analysis of an AtBAM1 knock-out mutant identified an additional redox sensitive β-amylase activity, which was most likely AtBAM3. A similar requirement for reducing conditions was observed for recombinant chloroplastic α-amylase (AtAMY3) activity. This study adds further candidates to the list of reductively activated starch metabolising enzymes and supports the view that redox regulation plays a role in starch metabolism.
- University of Copenhagen Denmark
- ETH Zurich Switzerland
- University of Copenhagen Denmark
Enzyme Activation, Chloroplasts, Arabidopsis Proteins, Amylases, Arabidopsis, Starch, Oxidation-Reduction
Enzyme Activation, Chloroplasts, Arabidopsis Proteins, Amylases, Arabidopsis, Starch, Oxidation-Reduction
10 Research products, page 1 of 1
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
- 2017IsRelatedTo
citations This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).61 popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.Top 10% influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).Top 10% impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.Top 10%
