Phosphatidylinositol Bisphosphate (PIP2)

Phosphatidylinositol (3,4)-bisphosphate is a minor phospholipid component of cell membranes, yet an important second messenger. The generation of PtdIns(3,4)P2 at the plasma membrane activates a number of important cell signaling pathways. Phosphatidylinositol (3,5)-bisphosphate is a minor phospholipid component of cell membranes, yet important in distinguishing cell compartments. PtdIns(3,5)P2 in internal membranes by the lipid kinase PIKfyve recruits a number of important proteins involved in regulating intracellular trafficking.Phosphatidylinositol 4,5-bisphosphate is a minor phospholipid component of cell membranes. PtdIns(4,5)P2 is enriched at the plasma membrane where it is an important substrate for a number of important signaling proteins.