Protein kinase C

The second messenger PIP3 formed by PI3K can be hydrolyzed to PIP2 by the phosphatase PTEN. PIP2 can be hydrolyzed to diacyl glycerol (DAG) and inositol trisphosphate (IP3) by phospholipase C (PLC). IP3 dissociates from the membrane into the cell, where it opens channels of intracellular vesicles, which store calcium. As a result, the intracellular intracellular calcium level rises. Calcium binds to protein kinase C (PKC) which is now able to bind to DAG, leading to the activation of the enzyme. Active PKC has many effects, e.g. phosphorylation and activation of the proto-oncoprotein Raf kinase.