Diacylglycerol (DAG)

Definition

Diacylglycerol (DAG) is a lipid-derived molecule that acts as a second messenger in cellular signal transduction pathways. It is produced by the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) and activates protein kinase C (PKC).

5 Must Know Facts For Your Next Test

1. DAG is generated from the cleavage of PIP2 by the enzyme phospholipase C (PLC).
2. It remains in the plasma membrane due to its hydrophobic nature.
3. DAG activates protein kinase C (PKC), which phosphorylates target proteins to propagate cellular signals.
4. It works in conjunction with another second messenger, inositol trisphosphate (IP3), to regulate intracellular calcium levels.
5. DAG plays a crucial role in various cellular processes, including cell growth, differentiation, and metabolism.

Review Questions

• How is diacylglycerol (DAG) produced during cell signaling?
• What is the primary function of DAG in signal transduction pathways?
• Which enzyme does DAG activate to propagate cellular signals?

Related terms

Phosphatidylinositol 4,5-bisphosphate (PIP2): A phospholipid found in the plasma membrane that is cleaved by PLC to produce DAG and IP3.

Protein Kinase C (PKC): An enzyme activated by DAG that phosphorylates specific target proteins involved in signal transduction.

Inositol trisphosphate (IP3): A second messenger produced alongside DAG from PIP2 cleavage that helps release calcium ions from intracellular stores.