Tyrosine phosphorylation of I kappa B-alpha activates NF-kappa B without proteolytic degradation of I kappa B-alpha
| Autor: | V, Imbert, R A, Rupec, A, Livolsi, H L, Pahl, E B, Traenckner, C, Mueller-Dieckmann, D, Farahifar, B, Rossi, P, Auberger, P A, Baeuerle, J F, Peyron |
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| Rok vydání: | 1996 |
| Předmět: |
Transcriptional Activation
T-Lymphocytes Molecular Sequence Data Alkaloids NF-KappaB Inhibitor alpha Tumor Cells Cultured Humans Enzyme Inhibitors Phosphorylation Calcimycin Protein Kinase C Base Sequence Ionophores NF-kappa B DNA Staurosporine Genistein Isoflavones Cell Hypoxia DNA-Binding Proteins src-Family Kinases Lymphocyte Specific Protein Tyrosine Kinase p56(lck) Leukocyte Common Antigens Tetradecanoylphorbol Acetate Tyrosine I-kappa B Proteins Protein Tyrosine Phosphatases Vanadates Protein Binding |
| Zdroj: | Cell. 86(5) |
| ISSN: | 0092-8674 |
| Popis: | The transcription factor NF-kappa B regulates genes participating in immune and inflammatory responses. In T lymphocytes, NF-kappa B is sequestered in the cytosol by the inhibitor I kappa B-alpha and released after serine phosphorylation of I kappa B-alpha that regulates its ubiquitin-dependent degradation. We report an alternative mechanism of NF-kappa B activation. Stimulation of Jurkat T cells with the protein tyrosine phosphatase inhibitor and T cell activator pervanadate led to NF-kappa B activation through tyrosine phosphorylation but not degradation of I kappa B-alpha. Pervanadate-induced I kappa B-alpha phosphorylation and NF-kappa B activation required expression of the T cell tyrosine kinase p56ick. Reoxygenation of hypoxic cells appeared as a physiological effector of I kappa B-alpha tyrosine phosphorylation. Tyrosine phosphorylation of I kappa B-alpha represents a proteolysis-independent mechanism of NF-kappa B activation that directly couples NF-kappa B to cellular tyrosine kinase. |
| Databáze: | OpenAIRE |
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