The debate over whether activated Ras can regulate phosphoinositide-specific phospholipase C (PLC) has been contentious and at times heated. The argument may be resolved by the recent identification of a novel Ras-regulated PLC, but some unexpected properties of this protein are sure to stimulate further controversy.

Addition of epidermal growth factor to A431 cells results in dramatic changes in cell morphology. Initially the cells form membrane ruffles accompanied by increased actin polymerization, followed by cell rounding. Activation of the tyrosine kinase of the receptor by binding epidermal growth factor leads also to phosphorylation and activation of phospholipase C-gamma 1, a key enzyme in the phosp...

In Dictyostelium discoideum extracellular cAMP induces chemotaxis via a transmembrane signal transduction cascade consisting of surface cAMP receptors, G-proteins and effector enzymes including adenylyl cyclase, guanylyl cyclase and phospholipase C. Previously it was demonstrated that some cAMP derivatives such as 3'-deoxy-3'-aminoadenosine 3':5'-monophosphate (3'NH-cAMP) bind to the receptor a...

1. Exposure of submitochondrial particles to phospholipases impaired the rate of oxidation as well as phosphorylation. Phospholipase A and phospholipase C were more inhibitory to phosphorylation and to NADH oxidation than to succinate oxidation. 2. At low concentrations of phospholipase A the inhibition of phosphorylation was prevented to a considerable extent by the presence of large amounts o...

Deoxycholate treatment of horse platelets previously labeled in their phospholipids with [“Clarachidonate produces selective conversion of [“Clphosphatidylinositol (PI) to [‘4C]1,2-diacylglycerol. This phospholipase C activity, which has a pH optimum of 7.5, is specific for phosphatidylinositol since other phospholipids or neutral lipids are not affected. Although exogenous Ca2+ is not required...