Ras Proteins as Potential Activators of Protein Kinase C Function

摘要: The structural and functional relationships of the products ras genes with known G proteins have suggested that ras-p21 s may be important mediators signal transduction pathways involved in cellular proliferation differentiation. One best characterized constitutes activation Ca++sensitive, phospholipid dependent protein kinase C (PKC), following receptor mediated hydrolysis inositol phospholipids by phospholipase (PLC). We investigated putative involvement modulation PLC, responsible for generation 1,2-diacylglycerol (DAG) phosphates (IPs), as well consequent PKC generated DAG. Utilizing Xenopus laevis oocytes we detected a rapid increase DAG after microinjection transforming H-ras p21 protein. Elevated basal levels were also observed NIH-3T3 cells transformed variety mutated without increased corresponding IPs. These results suggest novel source other than phosphatidyl phosphates. into previously devoided endogenous chronic treatment phorbol esters, lacked its otherwise potent mitogenic activity. function was regenerated under identical conditions co-microinjection . requirement activity ras. Finally, our previous findings 3T3 induces intracellular pH 0.15–0.2 units (Hagag et al. 1987) demonstrate can induce normal conditions. Taken together, all these imply regulators