Glycan analysis of olfactory and dorsal root ganglia neurons from wild type and beta3GnT1/2 knockout mice
CFG Member?
Yes subgroups :4 :Glycans in development and physiology
Request Details
Requester First Name:
Timothy
Requester Last Name:
Henion
Head of Lab. First Name:
Timothy
Head of Lab. Last Name:
Henion
Assigned First Name:
Timothy
Assigned Last Name:
Henion
Requester Email:
Timothy.Henion@umassmed.edu
Requester Interest:
Our laboratory focuses on glycan function during nervous system development. We primarily use the olfactory system as our model to investigate 1) the influence of Fringe glycosylation and Notch signaling on olfactory cell fate; 2) the role of protein-glycan interactions in patterning of sensory neuron projections to the CNS.
Request Date:
11/23/2005
Institution:
Eunice Kennedy Shriver Center/University of Massachusetts Medical School
Shipping Address:
Dr. Timothy Henion
Shriver Center
200 Trapelo Road
Waltham, MA 02452
Tel: (781)-642-0125
Comments:
This is a joint project currently being pursued with Dr. Gerald Schwarting, also of the Galectin subgroup of the CFG.
CFG Core:
C2
Amount Requested:
Experiment to be conducted:
Cell surface carbohydrates play an import role in axon guidance in the developing nervous system. Together with Dr. Gerald Schwarting, we are seeking to define specific glycan molecules and binding proteins that mediate patterning of sensory connections from peripheral to central targets in the brain. We have recently reported that knockout mice for the glycosyltransferase ?3GnT1/2 have severe olfactory axon guidance defects that are caused by the absence of a form of terminal lactosamine, which is a specific marker for many sensory neuron populations (J Neurosci. (2005) 25:1894-903). Recently, we've found by lectin analysis that wild-type but not ?3GnT1/2-deficient sensory neurons abundantly express polylactosamine glycans, suggesting that these structures may also function in axon guidance. It is likely that lactosamine interactions with Galectins that are abundantly expressed in the nasal mesenchyme play an important role in this system. We are currently examining this possibility using Galectin null mice obtained from the CFG Mouse Transgenic Core.
While the phenotype of ?3GnT1/2 null mice clearly implicates lactosamine and polylactosamine in axon pathfinding, our understanding of olfactory neuron glycosylation is limited to immunocytochemical and lectin analysis. There is clearly a pressing need to identify specific terminal glycans on wild-type sensory neurons that are lost from ?3GnT1/2 mice. Determining these structures at the molecular level is a critical step towards defining important molecular determinants for recognition by Galectins, and potentially other carbohydrate binding proteins. Our hope is that we can investigate this through MS analysis conducted as part of the Glycan Profiling mission of Core C. We can isolate olfactory and dorsal root ganglia neurons from wild-type and ?3GnT1/2 null mice for preparing material for comparative analysis of glycan structures. Depending on the starting material required, we should also be able to enrich for polylactosamine glycans from neuronal homogenates of wild-type mice using affinity chromatography. We look forward to your reply and further discussions regarding how this analysis might be best pursued.
Within Scope of Consortium:
Y
if yes, indicate the person responsible for inputing data into core B:
Timothy Henion
GBP being Addressed:
Galectin-1 and Galectin-9
Specific aims being addressed:
* 1. Define the specificity and affinity for carbohydrate ligands
* 3. Identify the ligand(s) that mediate GBP binding
* 4. Determine how GBP-ligand interactions mediate cell communication
* 6. Identify the glycosyltransferases that synthesize carbohydrate ligand(s)
Comments By Investigator
- Glycan analysis of olfactory epithelial tissues did not identify an unusually high proportion of poly-N-acetyllactosamine glycans in either wild-type or b3GnT1/2 mice.
- The resulting data will not be used in publication.
- All data generated is available on the CFG website for this request.