Group Leader:
Dr. Warren Wakarchuk
(613) 952-4299
Warren.Wakarchuk@nrc.gc.ca

Business Contact:
Scott Ferguson,
(613) 990-5948
Scott.Ferguson@nrc.gc.ca

Group Focus:
One of the goals of the Glycosyltransferases and Neuroglycomics Group is to explore the efficient production and use of the glycosyltransferase enzymes that make oligosaccharides to be exploited in the production of therapeutic agents. This involves the investigation of structure-function relationships in glycosyltransferases and accessory enzymes, by kinetic analysis, structure determination, and by site-directed mutagenesis. The development of new chemo-enzymatic strategies with glycosyltransferases and accessory enzymes for synthesis of a variety of potential therapeutics ensures that our work is always challenging and a great reason to come to work everyday.

A new direction was recently initiated to combine expertise in neurobiology with our previous work in glycobiology. Glycoconjugates contribute to cell-cell communication between pre-synaptic and post-synaptic neurons as well as between neurons and astrocytes. Currently we are focusing on the regulation of glycosyltransferase gene expression, identification of synaptic glycoconjugates in response to synaptic activities and their role in synaptic function under normal and pathological conditions.

The Team:
Dr. Stéphane Bernatchez, Marie-Claude Blanchard, Denis Brochu, Dr. Willard Costain Anna Cunningham, Dr. Hung Fang, Dr. Michel Gilbert, Marie-France Karwaski, Yan Li, Cathy Lorbetskie, Ingrid Rasquina, Melissa Schur, Lisa Willis, and Dr. Warren Wakarchuk

Ongoing Research Activities and Projects:
We have long had an interest in discovery of bacterial glycosyltransferases involved in biosynthesis of molecular mimics of human oligosaccharides. We have made major contributions to the understanding of glycosyltransferase enzyme structures, by characterizing in detail, including 3-dimensional structures, enzymes which make important carbohydrate linkages, as well as thoseinvolved in complex carbohydrate precursor biosynthetic pathways. We are continuing to examine structure/function activity of various glycosyltransferases, and to develop them for chemo-enzymatic synthesis of bioactive glycoconjugates.

Synapses are the fundamental functional units of the nervous system. Many synaptic proteins and lipids are glycosylated. Glycosylation status determines functional cell surface presentation of neurotransmitter receptors and regulates many ligand-receptor interactions. Currently, we are testing our hypothesis that synaptic signals, through transcription factor CREB, are capable of affecting the expression of certain glycosyltransferases causing changes in the glycosylation of synaptic components and consequently the properties of the synapse. In addition we are investigating molecular alterations at the CNS synapse as a result of ischemic brain injury or stroke. As a part of this, the relationship between structure and function is being investigated by evaluating the effect of cerebral ischemia on the expression of synaptic adhesion molecules and cytoskeleton associated proteins.

• Characterization of glycosyltransferases, including structure determination
• Understanding complex sugar biosynthesis and exploitation of the enzymes involved in the biosynthesis for in vitro carbohydrate synthesis
  
  
  

• Cloning and characterization of glycosyltransferases and related accessory enzymes
• Production, protein engineering and application of carbohydrate active enzymes for chemo-enzymatic synthesis
• Production of DNA libraries for activity screening of carbohydrate active enzymes
• Protein expression and purification, affinity chromatography, 1D and 2D gel separation and analysis, immunoblotting, immunohistochemistry.
• Gene profiling using cDNA microarray and Q-PCR.
• Characterization of transcription factors/gene promoter activities using chromatin-immunoprecipitation assay, reporter gene assays and electrophoretic mobility shift assays.
• In vitro primary cortical neuron model of ischemia-like (oxygen-glucose deprivation) or neurodegenerative injury.
• In vivo models of stroke.
• Isolation and biochemical characterization of synaptosomes.