Examples of Signaling intermediates (participate in transmitting signal)?

Phosphatidylinositol 4,5-bisphosphate in the cytoplasmic (inner) face of plasma membranes serves as a reservoir of messenger molecules that are released inside the cell in response to extracellular signals interacting with specific surface receptors inositol 1,4,5-trisphosphate (IP3), which is water-soluble, and diacylglycerol, which remains associated with the plasma membrane. IP3 triggers release of Ca2+ from the endoplasmic reticulum, and the combination of diacylglycerol and elevated cytosolic Ca2+ activates the enzyme protein kinase C. phosphatidylinositol 3,4,5-trisphosphate is a product of PI3K that serves as binding site for PH domain in several signal transduction molecules that propagate signal downstream of PI3K.