Characterization of a 23-kDa protein associated with CD40
| Autor: | Tomohiro Morio, Raif S. Geha, Silva H. Hanissian |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1995 |
| Předmět: |
Plasma protein binding
CD40 receptor complex Protein A/G Humans Electrophoresis Gel Two-Dimensional CD40 Antigens Cells Cultured B-Lymphocytes Multidisciplinary CD40 biology Sequence Homology Amino Acid Kinase Carcinoma Membrane Proteins hemic and immune systems Molecular biology Immunoglobulin Class Switching Precipitin Tests Protein kinase domain Immunoglobulin class switching Urinary Bladder Neoplasms biology.protein Signal transduction Sequence Analysis Research Article Protein Binding Signal Transduction |
| Popis: | CD40 is a 45-kDa glycoprotein member of the tumor necrosis factor receptor (TNFR) family expressed on B cells, thymic epithelial cells, dendritic cells, and some carcinoma cells. The unique capacity of CD40 to trigger immunoglobulin isotype switching is dependent on the activation of protein-tyrosine kinases, yet CD40 possesses no kinase domain and no known consensus sequences for binding to protein-tyrosine kinases. Recently, an intracellular protein (CD40bp/LAP-1/CRAF-1) which belongs to the family of TNFR-associated proteins was reported to associate with CD40. We describe a 23-kDa cell surface protein (p23) which is specifically associated with CD40 on B cells and on urinary bladder transitional carcinoma cells. Protein microsequencing revealed that p23 shows no homology to any known protein. A rabbit antibody raised against a peptide derived from p23 recognized a 23-kDa protein in CD40 immunoprecipitates. In contrast to CD40bp/LAP-1/CRAF-1, p23 was not associated with TNFR p80 (CD120b). These findings suggest that p23 is a novel member of the CD40 receptor complex. |
| Databáze: | OpenAIRE |
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