Journal article
Dynamics of starch granule biogenesis - the role of redox-regulated enzymes and low-affinity carbohydrate-binding modules
The deposition and degradation of starch in plants is subject to extensive post-translational regulation. To permit degradation of B-type crystallites present in tuberous and leaf starch these starch types are phosphorylated by glucan, water dikinase (GWD). At the level of post-translational redox regulation, ADPglucose pyrophosphorylase, beta-amylase (BAM1), limit dextrinase (LD), the starch phosphorylator GWD and the glucan phosphatase dual-specificity phosphatase 4 (DSP4), also named starch excess 4 (SEX4), are reductively activated in vitro.
Redox screens now suggest the presence of a substantially more extensive and coordinated redox regulation involving a larger number of enzymes. Noticeably several of these enzymes contain a new type of low-affinity carbohydrate-binding module that we term a low-affinity starch-binding domain or LA-SBD.
These are present in the CBM20, CBM45 and CBM53 families and can enable diurnal dynamics of starch-enzyme recognition. Such diurnal changes in starch binding have been indicated for the redox-regulated GWD and SEX4.
Language: | English |
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Year: | 2010 |
Pages: | 3-9 |
ISSN: | 10292446 and 10242422 |
Types: | Journal article |
DOI: | 10.3109/10242420903408211 |
ORCIDs: | Svensson, Birte and 0000-0001-6476-9546 |