Sonia Dorion

Research assistant with Jean Rivoal.

dorionsonia@hotmail.com

“Characterization of plant NDP Kinase: expression, regulation and function. Characterization of plant cytosolic triosephosphate isomerase.”

Sonia DorionMy main research project concerns the characterization of plant 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 autophosphorylaton for NDP Kinase. This autophosphorylation on a conserved Serine residue is involved in the regulation of NDP Kinase activity.

I also work on triosephosphate isomerase (TPI). We have determined that the cytosolic isoform of this enzyme is more aboundant than the plstidic 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 function of Cytosolic TPI in plants, we are currently characterizing transgenic roots modified to underexpress cytosolic TPI.

Background

  • Ph.D in Cellular and Molecular Biology, (2001) Université Laval
    Research project: Mechanisms of activation and desensitization of the p38 pathway by heat shock.
  • M.Sc. in Biology, option: Plant Physiology, (1996) Université de Montréal
    Research project: Drought-induced male sterility in wheat (Triticum aestivum L.): effect of meiotic-stage stress on carbohydrate metabolism in anthers.

Fellowships and awards

  • NSERC Postdoctoral fellowship
  • MRC PhD scholarship
  • NSERC Graduate scholaship

Publications

  • Dorion S., Dumas F., Rivoal J. (2006) Autophosphorylation of Solanum chacoense cytosolic nucleoside diphosphate kinase on Ser117: Identification, mutational analysis and potential regulatory mechanism. Journal of Experimental Botany 57: 4079-4088
  • Dorion S., Matton D.P., Rivoal J. (2006) Cloning and characterization of a cytosolic nucleoside diphosphate kinase associated with cell division and growth in potato. Planta 224 :108-124
  • Dorion S., Parveen, Jeukens J., Rivoal J. (2005) Characterization and expression of potato triosephosphate isomerase isoforms. In Photosynthesis: Fundamental Aspects to Global Perspectives, Vol 2 (A. van der Est, D. Bruce eds.), Allen Press. pp 903-905
  • Dorion S., Parveen, Jeukens J., Matton D.P., Rivoal J. (2005) Cloning and characterization of a cytosolic triosephosphate isomerase developmentally regulated in potato leaves. Plant Science 168: 183-194
  • Rivoal J., Dorion S., Claeyssen E., Zhang H. (2004) Organization of the plant cytosolic glycolytic pathway and its regulation by abiotic stresses in nonphotosynthetic tissues. In Recent Research Developments in Environmental Biology, Vol 1. (S.G. Pandalai ed.), Research Signpost. pp 77-100
  • Dorion S., Rivoal J. (2003) Quantification of uridine-diphosphate (UDP)-glucose by high-performance liquid chromatography and its application to a non radioactive assay for nucleoside diphosphate kinase using UDP-glucose pyrophosphorylase as coupling enzyme. Anal. Biochem., 323:188-196
  • Dorion S., Lambert H. et Landry J. (2002) Activation of the p38 signaling pathway by heat shock involves the dissociation of glutathione-S-transferase mu from Ask1. J. Biol. Chem. 277: 30792-30797
  • Dorion S. et Landry J. (2002) Activation of the MAP kinases by heat shock. Cell Stress & Chaperones 7:200-206
  • Dorion S., Bérubé J., Huot J., Landry, J. (1999) A short lived protein involved in the heat shock sensing mechanism responsible for stress-activated protein kinase 2 (SAPK2/p38) activation. J. Biol. Chem. 274:37591-37597
  • Dufresne C., Cormier F., Dorion S., Niggli U., Pfister S., Pfander H. (1999) Glycosylation of encapsulated crocetin by a Crocus sativus L. cell culture. Enzyme and Microbial Technology 24: 453-462
  • Dufresne C., Cormier F., Dorion S. (1997) In vitro formation of crocetin glucosyl esters by Crocus sativus L. callus extract. Planta Med. 1997 63:150-3
  • Dorion S., Lalonde S., Saini H.S. (1996) Induction of male sterility in wheat by meiotic-stage water deficit is preceded by a decline in invertase activity and changes in carbohydrate metabolism in anthers. Plant Physiol. 111: 137-145
  • Cormier F., Dufresne C., Dorion S. (1995) Enhanced crocetin glucosylation by means of maltosyl-b-cyclodextrin encapsulation. Biotechnology Techniques 9(8): 553-556

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