Signal transduction by p21ras.

Experiments using the physical loading of purified recombinant p21 ras proteins into quiescent normal cells to analyze how the proteins stimulate DNA synthesis and morphological transformation are reviewed. The results indicate that oncogenic p21ras proteins rapidly activate a protein-kinase-C-dependent pathway and a protein-kinase-C-independent pathway. The activation of protein kinase C is absolutely required for p21ras to stimulate DNA synthesis but is not required for morphological transformation.