Differential galactosylation of neuronal and haematopoietic signal regulatory protein-(α) determines its cellular binding-specificity
| Autor: | T K van den Berg, I. van Die, C. Renardel De Lavalette, N. Diaz, I. M. Van den Nieuwenhof |
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| Rok vydání: | 2001 |
| Předmět: |
Glycan
Glycosylation Recombinant Fusion Proteins Alpha (ethology) Neural Cell Adhesion Molecule L1 CHO Cells Biology PC12 Cells chemistry.chemical_compound Polysaccharides Cricetinae N-Acetyllactosamine Synthase Signal-regulatory protein alpha Animals Humans Receptors Immunologic Beta (finance) Neural Cell Adhesion Molecules Binding selectivity Neurons Membrane Glycoproteins CD47 Galactose Cell Biology Antigens Differentiation Molecular biology Immunoglobulin Fc Fragments Rats Haematopoiesis chemistry biology.protein |
| Zdroj: | Journal of Cell Science. 114:1321-1329 |
| ISSN: | 1477-9137 0021-9533 |
| DOI: | 10.1242/jcs.114.7.1321 |
| Popis: | Signal regulatory protein-alpha (SIRP alpha) is a member of the Ig superfamily selectively expressed by neuronal and myeloid cells. The molecule mediates functional interactions with CD47/integrin-associated protein. Here we provide evidence for the tissue-specific glycosylation of neuronal and haematopoietic SIRP alpha. We demonstrate a major difference in the galactosylation of N-linked glycans isolated from neuronal (i.e. brain-derived) SIRP alpha as compared to myeloid (i.e. spleen-derived) SIRP alpha, with neuronal SIRP alpha almost completely lacking galactose. beta 4-galactosyltransferase assays demonstrated that this is most likely due to a low galactosylation capacity of the brain. In order to investigate the role of galactosylation of SIRP alpha in cellular interactions, soluble recombinant SIRP alpha glycoforms containing galactose (SIRP alpha-Fc) or lacking galactose (SIRP alpha(Delta Gal)-Fc) were produced. Binding studies demonstrated superior binding of SIRP alpha(Delta Gal)-Fc to cerebellar neurons and isolated lymphocytes. In contrast, SIRP alpha-Fc bound relatively strong to macrophages. These data show that the galactosylation of SIRP alpha determines its cellular binding specificity. |
| Databáze: | OpenAIRE |
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