Role of interferon alpha/beta receptor chain 1 in the structure and transmembrane signaling of the interferon alpha/beta receptor complex
| Autor: | Chiang Wang, Lawrence M. Pfeffer, Aruna Murti, Leela Basu, Stefan N. Constantinescu, Jerald E. Mullersman, Croze Edward M |
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| Rok vydání: | 1994 |
| Předmět: |
Macromolecular Substances
Interleukin 5 receptor alpha subunit Alpha interferon Gene Expression Receptor Interferon alpha-beta Biology Transfection Interleukin 10 receptor alpha subunit Cell Line chemistry.chemical_compound Mice Tumor Cells Cultured Animals Humans Phosphorylation Phosphotyrosine Receptors Interferon Multidisciplinary Interferon-alpha/beta receptor Cell Membrane Antibodies Monoclonal Interferon-alpha Membrane Proteins Tyrosine phosphorylation Molecular biology chemistry Cell culture Tyrosine Signal transduction HeLa Cells Signal Transduction Research Article |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America. 91(20) |
| ISSN: | 0027-8424 |
| Popis: | A previously cloned cDNA encodes one subunit of the human interferon alpha/beta receptor (IFN alpha R), denoted IFN alpha R1. To study the expression and signaling of IFN alpha R1, we used monoclonal antibodies (mAbs) generated against the baculovirus-expressed ectodomain of IFN alpha R1. Immunoprecipitation and immunoblotting of lysates from a variety of human cell lines showed that IFN alpha R1 has an apparent molecular mass of 135 kDa. Binding analysis with 125I-labeled mAb demonstrated high levels of cell surface expression of IFN alpha R1 in human cells and in mouse cells transfected with IFN alpha R1 cDNA, whereas no cross-reactivity was observed in control mouse L929 cells expressing only the endogenous mouse receptor. The subunit was rapidly down-regulated by IFN alpha (80% decrease within 2 hr) and degraded upon internalization. The IFN alpha R1 chain appeared to be constitutively associated with the 115-kDa subunit of the IFN alpha/beta receptor, since the mAbs coprecipitated this protein. IFN alpha/beta treatment induced tyrosine phosphorylation of IFN alpha R1 within 1 min, with kinetics paralleling that of the IFN-activated protein-tyrosine kinases Jak1 and Tyk2. Ligand-induced tyrosine phosphorylation of IFN alpha R1 was blocked by the kinase inhibitors genistein or staurosporine. Although IFN alpha R1 cDNA-transfected mouse cells expressed high levels of this subunit when compared with empty vector-transfected cells the number of binding sites for human IFN alpha (50-75 sites per cell) was not increased. Human IFN alpha induced the expression of a mouse IFN alpha/beta-responsive gene (the 204 gene) in mouse L929 cells transfected with the IFN alpha R1 cDNA, but not in mock-transfected cells. These results suggest that the IFN alpha R1 subunit acts as a species-specific signal transduction component of the IFN alpha/beta receptor complex. |
| Databáze: | OpenAIRE |
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