Heterotrimeric guanine nucleotide binding proteins function in the coupling of a diverse span of cell surface receptors to a variety of intracellular signaling pathways, some of which stimulate cellular proliferation. With the recent discovery that mutated forms of G proteins are present in specific tumors, there has been an increased interest in the determination of the role of specific subtypes of G proteins in the regulation of cellular growth. We have attempted to determine which subtypes of G proteins are directly involved in serum-stimulated DNA synthesis through microinjection of inhibitory antibodies into living cells. Inhibitory rabbit polyclonal antibodies directed against specific G(i) α subunits were introduced into living Balb/c 3T3 fibroblasts by microinjection, and the effect upon serum-stimulated DNA synthesis was examined. Results of these experiments indicate that G(i2) plays a direct role in serum-stimulated DNA synthesis in living cells and suggest that G proteins may function in a variety of mitogenic signaling pathways initiated by serum growth factors.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Biological Chemistry|
|State||Published - Jan 1 1992|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology