Starch phosphorylation: a new front line in starch research

• Published in: Trends in Plant Science Vol. 7; no. 10; pp. 445 - 450
• Main Authors: Blennow, Andreas, Nielsen, Tom H, Baunsgaard, Lone, Mikkelsen, René, Engelsen, Søren B
• Format: Book Review Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-10-2002; Elsevier
• Subjects: Amylopectin - metabolism; Amylose - metabolism; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological and medical sciences; carbohydrate regulation; crystallinity; Fundamental and applied biological sciences. Psychology; Glucose-1-Phosphate Adenylyltransferase; Metabolism; Models, Molecular; molecular model; Monosaccharide Transport Proteins - genetics; Monosaccharide Transport Proteins - metabolism; Nucleotidyltransferases - metabolism; Phosphorylation; Photosynthesis, respiration. Anabolism, catabolism; Plant physiology and development; Plants - genetics; Plants - metabolism; Research - trends; sex1; Starch; Starch - biosynthesis; Starch - chemistry; Starch - metabolism; starch branching enzyme; starch excess; starch phosphate; starch synthase; starch phosphate; Plant Science; Biotechnology; molecular model; Starch; carbohydrate regulation; starch synthase; crystallinity; Biochemistry; starch excess; starch branching enzyme; Physiology; phosphorylation; sex1; Phosphorylation; Enzyme; Transferases; Cellulose; Review; Metabolism; Arabidopsis thaliana; Enzymatic activity; Cruciferae; Kinase; Dicotyledones; Angiospermae; Spermatophyta; Carbohydrate; Models; Experimental plant; Mechanism of action
• ISSN: 1360-1385; 1878-4372
• DOI: 10.1016/S1360-1385(02)02332-4

Starch is the primary energy reserve in higher plants and is, after cellulose, the second most abundant carbohydrate in the biosphere. It is also the most important energy source in the human diet and, being a biodegradable polymer with well-defined chemical properties, has an enormous potential as a versatile renewable resource. The only naturally occurring covalent modification of starch is phosphorylation. Starch phosphate esters were discovered a century ago but were long regarded as a curiosity, receiving little attention. Indeed, the mechanism for starch phosphorylation remained completely unknown until recently. The starch-phosphorylating enzyme is an α-glucan water dikinase. It is now known that starch phosphorylation plays a central role in starch metabolism.
The starch-phosphorylating enzyme has been discovered a century after phosphate monoesters were found in potato starch. sex1 mutants are being re-evaluated and a physiological role of starch phosphorylation is slowly emerging.