RRC ID |
15327
|
著者 |
Santelia D, Kötting O, Seung D, Schubert M, Thalmann M, Bischof S, Meekins DA, Lutz A, Patron N, Gentry MS, Allain FH, Zeeman SC.
|
タイトル |
The phosphoglucan phosphatase like sex Four2 dephosphorylates starch at the C3-position in Arabidopsis.
|
ジャーナル |
Plant Cell
|
Abstract |
Starch contains phosphate covalently bound to the C6-position (70 to 80% of total bound phosphate) and the C3-position (20 to 30%) of the glucosyl residues of the amylopectin fraction. In plants, the transient phosphorylation of starch renders the granule surface more accessible to glucan hydrolyzing enzymes and is required for proper starch degradation. Phosphate also confers desired properties to starch-derived pastes for industrial applications. In Arabidopsis thaliana, the removal of phosphate by the glucan phosphatase Starch Excess4 (SEX4) is essential for starch breakdown. We identified a homolog of SEX4, LSF2 (Like Sex Four2), as a novel enzyme involved in starch metabolism in Arabidopsis chloroplasts. Unlike SEX4, LSF2 does not have a carbohydrate binding module. Nevertheless, it binds to starch and specifically hydrolyzes phosphate from the C3-position. As a consequence, lsf2 mutant starch has elevated levels of C3-bound phosphate. SEX4 can release phosphate from both the C6- and the C3-positions, resulting in partial functional overlap with LSF2. However, compared with sex4 single mutants, the lsf2 sex4 double mutants have a more severe starch-excess phenotype, impaired growth, and a further change in the proportion of C3- and C6-bound phosphate. These findings significantly advance our understanding of the metabolism of phosphate in starch and provide innovative options for tailoring novel starches with improved functionality for industry.
|
巻・号 |
23(11)
|
ページ |
4096-111
|
公開日 |
2011-11-1
|
DOI |
10.1105/tpc.111.092155
|
PII |
tpc.111.092155
|
PMID |
22100529
|
PMC |
PMC3246334
|
MeSH |
Amylopectin / metabolism
Arabidopsis / genetics
Arabidopsis / growth & development
Arabidopsis / metabolism*
Arabidopsis Proteins / chemistry
Arabidopsis Proteins / genetics
Arabidopsis Proteins / metabolism*
Chloroplasts / metabolism
Dual-Specificity Phosphatases / genetics
Dual-Specificity Phosphatases / metabolism*
Glucans / metabolism
Models, Molecular
Mutation
Phenotype
Phosphates / metabolism
Protein Conformation
Sequence Homology, Amino Acid
Starch / chemistry
Starch / metabolism*
Substrate Specificity
|
IF |
9.618
|
引用数 |
70
|
WOS 分野
|
PLANT SCIENCES
BIOCHEMISTRY & MOLECULAR BIOLOGY
CELL BIOLOGY
|
リソース情報 |
シロイヌナズナ / 植物培養細胞・遺伝子 |
pdx93940
pdy29091
pdy30584
pdz29685
pdz82152 |