Background:Converts phosphatidylinositol 3,4,5-trisphosphate(PtdIns 3,4,5-P3) to PtdIns-P2, and phosphatidylinositol 4,5-bisphosphate to phosphatidylinositol 4-phosphate. Specific for lipid substrates, inactive towards water soluble inositol phosphates.