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Entry URI http://metadb.riken.jp/db/SciNetS_ria224i/cria224u4ria224u15686522i
Entry name Baunsgaard Lone et al. 2005 Feb. Plant J. 41(4):595-605.
Title A novel isoform of glucan, water dikinase phosphorylates pre-phosphorylated alpha-glucans and is involved in starch degradation in Arabidopsis.
Authors Baunsgaard Lone|Blennow Andreas|Glaring Mikkel A|L端tken Henrik|Mikkelsen Ren辿|Pham Tam T
Abstract An Arabidopsis thaliana gene encoding a homologue of the potato alpha-glucan, water dikinase GWD, previously known as R1, was identified by screening the Arabidopsis genome and named AtGWD3. The AtGWD3 cDNA was isolated, heterologously expressed and the protein was purified to apparent homogeneity to determine the enzymatic function. In contrast to the potato GWD protein, the AtGWD3 primarily catalysed phosphorylation at the C-3 position of the glucose unit of preferably pre-phosphorylated amylopectin substrate with long side chains. An Arabidopsis mutant, termed Atgwd3, with downregulated expression of the AtGWD3 gene was analysed. In Atgwd3 the amount of leaf starch was constantly higher than wild type during the diurnal cycle. Compared with wild-type leaf starch, the level of C-3 phosphorylation of the glucosyl moiety of starch in this mutant was reduced. Taken together, these data indicate that the C-3 linked phospho-ester in starch plays a so far unnoticed specific role in the degradation of transitory starch.
Pubmed ID 15686522
Journal The Plant journal
Volume 41
Issue 4
Pages 595-605
Publication date 2005 Feb
Num of phenotype gene 0