Functional characterization of NCAM fibronectin type III domains: demonstration of modulatory effects of the proline-rich sequence encoded by alternatively spliced exons a and AAG
| Autor: | Vladimir Berezin, Christina Kasper, Elisabeth Bock, Klaus Edvardsen, Vladislav Soroka, Vladislav V. Kiselyov, Martin Stahlhut, Thomas E. Maar |
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| Rok vydání: | 1996 |
| Předmět: |
Proline
Blotting Western Cell Communication Cell morphology Cellular and Molecular Neuroscience Immunoglobulin Fab Fragments Mice L Cells Cerebellum Neurites Animals Growth cone Neural Cell Adhesion Molecules chemistry.chemical_classification biology Exons Fusion protein Cell aggregation Transmembrane protein Cell biology Amino acid Fibronectins Rats Fibronectin nervous system chemistry biology.protein Neural cell adhesion molecule |
| Zdroj: | Journal of neuroscience research. 46(2) |
| ISSN: | 0360-4012 |
| Popis: | In order to characterize the functions of the two fibronectin type III (F3) homology domains of the neural cell adhesion molecule (NCAM), we investigated the effects of two variants, expressed as fusion proteins, of the NCAM-F3 domains on attachment and spreading of NCAM-expressing fibroblasts, cerebellar cell aggregation and fiber formation, and on growth cones. The two fusion proteins were different with regard to a short proline-rich insert of six amino acids between the two F3 domains. Immobilized NCAM-F3 fusion proteins were found to mediate attachment of both transmembrane and lipid-anchored NCAM expressing fibroblasts. Also NCAM-negative cells adhered to the NCAM-F3 substratum, although to a lesser extent, implying the possibility of a heterophilic ligand to NCAM-F3 domains on the surface of fibroblasts. Cellular spreading on NCAM-F3 substratum was selectively increased in fibroblasts expressing transmembrane NCAM, and only the NCAM-F3 fusion protein lacking the proline-rich insert was able to elicit this effect. Primary cultures of mouse cerebellum were strongly inhibited with regard to formation of cellular aggregates and fibers, when incubated in the presence of either of the two NCAM-F3 fusion proteins, the fusion protein with the proline-rich insert being the more effective one. Finally, the morphology of growth cones from rat cerebellar granule cells changed significantly when grown on NCAM-F3 substrata as revealed by computer-assisted image analysis. Thus, our data indicate that the NCAM-F3 domain are involved in cell-cell adhesion, and that insertion of the proline-rich sequence has a modulatory effect on NCAM-F3 domain functions. |
| Databáze: | OpenAIRE |
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