Title : Human
transferrin receptor contains O-linked oligosaccharides
Abstract :
- We have investigated the oligosaccharides in the human transferrin receptor from three different cell lines
- During our studies on the structures of the N-linked oligosaccharides of the receptor , we discovered that the receptor contains O-linked oligosaccharides
- This report describes the isolation and characterization of these O-linked oligosaccharides
- Three different human cell lines--K562, A431, and BeWo--were grown in media containing either [2-3H] mannose or [6-3H]glucosamine
- The newly synthesized and radiolabeled transferrin receptors were purified by immunoprecipitation from cell extracts and sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- The receptor was proteolytically digested or treated directly with mild base/borohydride
- The released radiolabeled glycopeptides and oligosaccharides were separated by a variety of chromatographic techniques, and their structures were analyzed
- The transferrin receptor from all three cell types contains O-linked oligosaccharides that are released from peptide by mild base/borohydride treatment
- The receptor from K562 cells contains at least one O-linked oligosaccharide having two sialic acid residues and a core structure of the disaccharide galactose-N-acetyl-galactosamine
- In contrast, the O-linked oligosaccharides in the transferring receptors from both A431 and BeWo cell lines are not as highly sialylated and were identified as both the neutral disaccharide galactose-N-acetylgalactosamine and the neutral monosaccharide N-acetylgalactosamine
- In addition, the receptors from all three cell lines contain both complex-type and high mannose-type N-linked oligosaccharides
- The complex-type chains in the receptor from A431 cells have properties of blood group A antigens, whereas oligosaccharides in receptors from both BeWo and K562 cells lack these properties
- These results are interesting since both A431 and BeWo cells, but not K562 cells, are positive for blood group A antigens
- Thus, our results demonstrate that the human transferrin receptor contains O-linked oligosaccharides and that there are differences in the structures of both the O-linked and complex-type N-linked oligosaccharides on the receptors synthesized by different cell types
Output (sent_index, trigger,
protein,
sugar,
site):
- 0. contains, , transferrin receptor, O-linked oligosaccharides, -
- 1. oligosaccharides, , transferrin receptor, oligosaccharides, -
- 10. oligosaccharides, , receptors, oligosaccharides, -
- 10. sialylated, , -, the O-linked oligosaccharides, -
- 10. sialylated, , -, the neutral disaccharide galactose-N-acetylgalactosamine, -
- 10. sialylated, , -, the neutral monosaccharide N-acetylgalactosamine, -
- 11. contain, , receptors, both complex-type and high mannose-type N-linked oligosaccharides, -
- 11. lines, , receptors, lines, -
- 12. chains, , receptor, chains, -
- 12. oligosaccharides, , receptors, oligosaccharides, -
- 14. contains, , transferrin receptor, O-linked oligosaccharides, -
- 14. oligosaccharides, , receptors, oligosaccharides, -
- 2. contains, , receptor, O-linked oligosaccharides, -
- 2. receptor, , receptor, the N-linked oligosaccharides, -
- 7. glycopeptides, , -, -, glycopeptides
- 8. contains, , transferrin receptor, O-linked oligosaccharides, -
- 8. released, , -, O-linked oligosaccharides, peptide
- 8. types, , transferrin receptor, types, -
- 9. contains, , receptor, at least one O-linked oligosaccharide, -
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):