Enhancement of TNF-alpha synthesis by overexpression of G alpha z in a mast cell line
| Autor: | R A Baumgartner, N Hirasawa, K Ozawa, F Gusovsky, M A Beaven |
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| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 157:1625-1629 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.157.4.1625 |
| Popis: | Ag stimulation of mast cells via the IgE receptor (Fc epsilon RI) elicits production and release of numerous cytokines. This activation of Fc epsilon RI initiates various tyrosine kinase-dependent signaling cascades, which ultimately result in the de novo synthesis of cytokines. To date, no heterotrimeric G proteins have been implicated in this process. Here we report that the alpha subunit of the heterotrimeric G protein, Gz, can regulate production of the cytokine, TNF-alpha. The alpha subunit was overexpressed in a cultured mast cell line (RBL-2H3) known to contain G alpha z. In stimulated cells, overexpression of G alpha z significantly enhanced the production of TNF-alpha. This effect of G alpha z appeared to be restricted in that constitutive synthesis of the cytokine, TGF-beta, and Ag-stimulation of the phosphoinositide-dependent secretory pathway were not significantly affected. Thus, G alpha z, a heterotrimeric G protein, appeared to modulate the stimulatory pathways for induction of TNF-alpha synthesis in RBL-2H3 cells. |
| Databáze: | OpenAIRE |
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