Characterization of plant nucleoside diphosphate kinase: expression, regulation and function
My main research project concerns the characterization of plant nucleoside diphosphate kinase (NDP Kinase). This enzyme is implicated in nucleoside triphosphate metabolism. We have set up a specific assay to measure the activity of this enzyme. We have demonstrated that cytosolic NDP Kinase is associated with plant growth and preferentially expressed in meristematic tissues. We have also identified and characterized a mechanism of autophosphorylation for NDP Kinase. This autophosphorylation on a conserved Serine residue is involved in the regulation of NDP Kinase activity. We have characterized the role of this enzyme using transgenic roots. Our results demonstrate that the level of expression of cytosolic NDP Kinase influences growth, respiration and the balance between carbon fluxes to the starch and cellulose biosynthetic pathways.
Characterization of plant cytosolic triosephosphate isomerase
I also work on triosephosphate isomerase (TPI). We have determined that the cytosolic isoform of this enzyme is more abundant than the plastidic isoform in all potato tissues. We have also shown that cytosolic TPI is differentially expressed in leaves during development. In order to better understand the role of cytosolic TPI in plants, we have characterized transgenic roots modified with an antisense construct for this enzyme. This study revealed that a decrease in the activity of cytosolic TPI results in a partial redirection of the carbon flow from glycolysis to the pentose phosphate pathway.
Ph.D. in cellular and molecular biology, (2001) University of Laval
Research project: Mechanisms of activation and desensitization of the p38 pathway by heat shock.
M.Sc. in biology, option: Plant Physiology, (1996) University of Montreal
Research project: Drought-induced male sterility in wheat (Triticum aestivum L.): effect of meiotic-stage stress on carbohydrate metabolism in anthers.