Ag stimulation of mast cells via the IgE receptor (Fc∈RI) elicits production and release of numerous cytokines. This activation of Fc∈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 a subunit of the heterotrimeric G protein, Gz, can regulate production of the cytokine, TNF-α. The α subunit was overexpressed in a cultured mast cell line (RBL-2H3) known to contain Gαz. In stimulated cells, overexpression of Gαz significantly enhanced the production of TNF-α. This effect of Gαz appeared to be restricted in that constitutive synthesis of the cytokine, TGF-β, and Ag-stimulation of the phosphoinositide-dependent secretory pathway were not significantly affected. Thus, Gaz, a heterotrimeric G protein, appeared to modulate the stimulatory pathways for induction of TNF-α synthesis in RBL-2H3 cells.
|Number of pages||5|
|Journal||Journal of Immunology|
|Publication status||Published - 1996 Aug 15|
ASJC Scopus subject areas
- Immunology and Allergy