type I PIP kinases
Phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) occupies an essential position in the phosphoinositide signal transduction cascades as the precursor to second messengers.
Its functions include regulation of secretion, cell proliferation, differentiation, and motility.
The final step in the synthesis of PtdIns(4,5)P2 is the phosphorylation of PtdIns(4)P (also known as PIP ) by type I PIP kinases, or the phosphorylation of PtdIns(5)P by type II PIP kinases, such as PIP5K2A.