Selective activation of phospholipase D-2 by unsaturated fatty acid

Although oleate has been implicated in the regulation of phospholipase D (P LD) activity, the molecular identity of the oleate-stimulated PLD is still poorly understood. We now report that oleate selectively stimulates the enz ymatic activity of PLD2 but not of PLD1, with an optimal concentration of 2 0 mu M in vitro. Intriguingly, phosphatidylinositol 4,5-bisphosphate (PIP2) synergistically stimulates the oleate-dependent PLD2 activity with an opti mal concentration of 2.5 mu M. These results provide the first evidence tha t oleate is a PLD2-specific activating factor and PLD2 activity is synergis tically stimulated by oleate and PIP2, (C) 1999 Federation of European Bioc hemical Societies.