Regulation of carbohydrate metabolism

The primary carbohydrate metabolism is responsible for the major flux of photosynthetic products in the plant.  This metabolism is a network of reactions which is closely regulated by the plant. The regulation of individual reactions determines distribution of assimilates in the cells. Our research focus on characterizing specific enzymes which hold a key position in this network.

Much of our work has focused on the signal metabolite Fructose-2,6-bisphosphate (F26BP). F26BP  modifies the activity of specific enzymes in all eukaryotic organisms. These enzymes mediate the metabolism of hexose-phosphates, and in plants F26BP is important for carbon flux, especially in relation to sucrose and starch formation. F26BP is both formed and degraded by a specific bifunctional enzyme (Fru-6-P,2-kinase/ Fru-2,6-BPase). We have characterized the kinetic and molecular properties of the plant enzyme (called F2KP), and we have isolated knock-out mutants which cannot form any Fru-2,6-bisP. We plan to produce plants with new versions of F2KP, engineered to serve as tools for studying the molecular interactions with other cell components.

 

Selected reference:
Nielsen TH, Rung JH, Villadsen D, (2004) Fructose-2,6-bisphosphate: a traffic signal in plant metabolism. Trends in Plant Science, 9: 556-563.