Moody, A M and Chui, D and Reche, Pedro A and Priatel, J J and Marth, J D and Reinherz, Ellis L (2001) Developmentally regulated glycosylation of the CD8alphabeta coreceptor stalk modulates ligand binding. Cell, 107 (4). pp. 501-12. ISSN 0092-8674
Official URL: http://www.cell.com/home
The functional consequences of glycan structural changes associated with cellular differentiation are ill defined. Herein, we investigate the role of glycan adducts to the O-glycosylated polypeptide stalk tethering the CD8alphabeta coreceptor to the thymocyte surface. We show that immature CD4(+)CD8(+) double-positive thymocytes bind MHCI tetramers more avidly than mature CD8 single-positive thymocytes, and that this differential binding is governed by developmentally programmed O-glycan modification controlled by the ST3Gal-I sialyltransferase. ST3Gal-I induction and attendant core 1 sialic acid addition to CD8beta on mature thymocytes decreases CD8alphabeta-MHCI avidity by altering CD8alphabeta domain-domain association and/or orientation. Hence, glycans on the CD8beta stalk appear to modulate the ability of the distal binding surface of the dimeric CD8 globular head domains to clamp MHCI.
|Subjects:||Medical sciences > Medicine > Immunology|
Medical sciences > Biology > Molecular biology
|Deposited On:||14 Aug 2009 12:06|
|Last Modified:||25 Aug 2010 10:24|
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