HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Baldwin, T. A. Articles by Ostergaard, H. L. Search for Related Content PubMed PubMed Citation Articles by Baldwin, T. A. Articles by Ostergaard, H. L. Pubmed/NCBI databases Gene GEO Profiles HomoloGene UniGene Substance via MeSH

Developmentally Regulated Changes in Glucosidase II Association with, and Carbohydrate Content of, the Protein Tyrosine Phosphatase CD45¹

Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada

Glucosidase II (GII) stably interacts with the external domain of CD45 in a carbohydrate-dependent manner. We have found that the association occurs in immature cells, but is significantly reduced in mature T cells. Using mannose-binding protein (MBP), in both FACS analysis and pull-down assays, we find that MBP can specifically recognize cell surface CD45 from immature, but not mature T cells. Analysis of thymocytes reveals increased MBP binding and GII association with CD45 in double-positive thymocytes compared with either double-negative or single-positive thymocytes. As well, the same pool of CD45 recognized by MBP can also associate with GII. Initial analysis of the basis of the interaction between CD45 and MBP suggests MBP binds two different glycoforms of CD45 based on the differential competition with glucose. Finally, inhibition of GII activity in cells that do not normally express MBP ligands results in significant increases in cell surface MBP ligands, including CD45. Taken together, these data suggest that the glucose content of the cell surface CD45 changes as thymocytes undergo maturation to mature T cells, and may be regulated by GII interactions. Such changes in the cell surface carbohydrate on CD45 may affect the development of thymocytes, perhaps via binding of CD45 on thymocytes to lectins on stromal cells.

This article has been cited by other articles:

				R. Dawes, S. Petrova, Z. Liu, D. Wraith, P. C. L. Beverley, and E. Z. Tchilian Combinations of CD45 Isoforms Are Crucial for Immune Function and Disease J. Immunol., March 15, 2006; 176(6): 3417 - 3425. [Abstract] [Full Text] [PDF]

				E. Z. Tchilian, R. Dawes, L. Hyland, M. Montoya, A. Le Bon, P. Borrow, S. Hou, D. Tough, and P. C. L. Beverley Altered CD45 isoform expression affects lymphocyte function in CD45 Tg mice Int. Immunol., September 1, 2004; 16(9): 1323 - 1332. [Abstract] [Full Text] [PDF]

				T. Stanton, S. Boxall, K. Hirai, R. Dawes, S. Tonks, T. Yasui, Y. Kanaoka, N. Yuldasheva, O. Ishiko, W. Bodmer, et al. A high-frequency polymorphism in exon 6 of the CD45 tyrosine phosphatase gene (PTPRC) resulting in altered isoform expression PNAS, May 13, 2003; 100(10): 5997 - 6002. [Abstract] [Full Text] [PDF]

				T. A. Baldwin and H. L. Ostergaard The Protein-tyrosine Phosphatase CD45 Reaches the Cell Surface via Golgi-dependent and -independent Pathways J. Biol. Chem., December 20, 2002; 277(52): 50333 - 50340. [Abstract] [Full Text] [PDF]