Glycosylation of Caenorhabditis elegans II

The model organism, Caenorhabditis elegans, is much studied at the genetic level; however, its glycosylation – a set of key modifications of all cell surfaces – is still poorly understood. Recent data from this and other laboratories suggest that the carbohydrates covalently-bound to nematode glycoproteins share some basic features with those found in mammals, but have some novel decorations. In particular, the presence of asparagine-linked glycan structures with up to four fucose residues and two O-methyl substitutions, as well as phosphorylcholine, is highly intriguing. O-methylated residues have also been found on the nematode’s O-linked oligosaccharides and phosphorylcholine-modified glycolipids are also known. Some of these features are shared, at least in part, by parasitic nematodes and so Caenorhabditis elegans is potentially a useful model for developing novel strategies in the study of these types of oligosaccharides with potential benefits in combatting nematode parasites. In our work to date, we have identified two of the putative four fucosyltransferases involved in N-glycan biosynthesis in the worm and determined the basis of anti-horseradish peroxidase staining in Caenorhabditis. In the proposed study, it is intended to extend our studies on the fucosylation of of the N-glycans of Caenorhabditis. In particular, the activity of natural and recombinant fucosyltransferases of Caenorhabditis and parasitic nematodes will be examined, with particular emphasis on assaying fucosyltransferase activities and examining the glycan structures of wild-type and mutant Caenorhabditis extracts. The expression pattern of various fucosyltransferases in the worm will be also studied. By these approaches we will gain insight into which fucosyltransferases are required for the biosynthesis of nematode-specific features, with the longer-term aim of determining which types of glycans may have a role in the immune response to parasitic nematodes.