ABSTRACT
Axonal transport of glycoproteins has been documented after use of a variety of carbohydrate precursors including 3H-fucose, 3H-glucosamine, 3H-galactosamine, and 3H-galactose. The localization of specific glycoproteins to particular cells of the nervous system remains largely unexplored. The discovery of axonally transported proteoglycans in synaptic vesicles and their exposure upon nerve stimulation suggests a similar function for the transported proteoglycans. The widespread implication of glycoconjugates in processes of cell-cell and cell-substrate interaction raises a question as to whether axonally transported glycoproteins and proteoglycans play such a role in axonal ontogeny and regeneration. A binding have been noted in several developing axonal preparations and direct compositional analysis of glycoproteins transported into regenerating olfactory nerve axons has shown a major increase in the presence of Concanavalin A (Con A) binding polymannosyl chains. The relatively high axonal transport labeling of glycoproteins in synaptic plasma membrane and synaptic vesicles imply a role in some aspects of normal synaptic physiology.
