Phosphatidylinositol 4,5-bisphosphate

Phosphatidylinositol 4,5-bisphosphate (PIP₂) is a phospholipid that covers a small percentage of the cell membrane. Interaction with phospholipase C results in the production of inositol 1,4,5-trisphosphate (IP₃), which causes Ca²⁺ to be released from the endoplasmic reticulum, and diacylglycerol (DAG). Ca²⁺ and DAG activate protein kinase C, which regulates other proteins by phosphorylation. This interaction is part of the phosphoinositide pathway.