| Research Abstract |
In this research, an extremely useful genome organism, C. elegans, was used for elucidation of physiological functions of galectins in this organism. For this purpose, two affinity approaches were taken : i.e., one is to identify endogenous glycoprotein ligands in the nematode, and the other is to clarify fine carbohydrate specificities of individual galectins. For the former approach, a recently developed "glyco-catch" method was utilized, and identification of genes that encode glycoproteins specifically recognized by representative nematode galectins, LEC-6 and LEC-10, was attempted starting with a solubilized membrane fraction. As a result, some 10 candidate genes were successfully identified. As expected, these genes encoded proteins having membrane-anchoring domain(s), and having potential glycosylation sites in presumed extracellular domains. Thus, the proposed glyco-catch method has proved to work properly. Further, it was shown that groups of glycoproteins that were captured by galectins and those captured by concanavalin A are totally different. This means that types of glycans, i.e., complex type (recognized by galectins) or high-mannose type (recognized by concanavalin A), are basically destined at the gene level in the nematode. Such a finding should never be expected by conventional approaches. By making maximal use of the above two affinity techniques even to more complex organisms, it will become possible to pioneer a new research field, i.e., "comparative glycomics".
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