An endogenous Drosophila receptor for glycans bearing alpha 1,3-linked core fucose residues.
The genome of Drosophila melanogaster encodes several proteins that are predicted to contain Ca(2+)-dependent, C-type carbohydrate-recognition domains. The CG2958 gene encodes a protein containing 359 amino acid residues. Analysis of the CG2958 sequence suggests that it consists of an N-terminal domain found in other Drosophila proteins, a middle segment that is unique, and a C-terminal C-type carbohydrate-recognition domain. Expression studies show that the full-length protein is a tetramer formed by noncovalent association of disulfide-linked dimers that are linked through cysteine residues in the N-terminal domain. The expressed protein binds to immobilized yeast invertase through the C-terminal carbohydrate-recognition domain. Competition binding studies using monosaccharides demonstrate that CG2958 interacts specifically with fucose and mannose. Fucose binds approximately 5-fold better than mannose. Blotting studies reveal that the best glycoprotein ligands are those that contain N-linked glycans bearing alpha1,3-linked fucose residues. Binding is enhanced by the additional presence of alpha1,6-linked fucose. It has previously been proposed that labeling of the Drosophila neural system by anti-horseradish peroxidase antibodies is a result of the presence of difucosylated N-linked glycans. CG2958 is a potential endogenous receptor for such neural-specific carbohydrate epitopes.
Bouyain
Samuel
S
Glycobiology Institute, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom.
Silk
Nicholas J
NJ
Fabini
Gustáv
G
Drickamer
Kurt
K
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000737:chemistry; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D029721:Drosophila Proteins / Q000737:chemistry* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes; D005643:Fucose / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000737:chemistry; D009474:Neurons / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
D002241:Carbohydrates; D018076:DNA, Complementary; D029721:Drosophila Proteins; D000939:Epitopes; D009005:Monosaccharides; D011134:Polysaccharides; C459805:lectin-24Db protein, Drosophila; D005643:Fucose