Related Experiment Video
Updated: Jul 19, 2026

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
Published on: March 9, 2012
The lipid second messenger diacylglycerol as a negative regulator of Rac signalling
1Department of Pharmacology, University of Pennsylvania School of Medicine, 816 BRB II/III, 421 Curie Blvd, Philadelphia, PA 19104-6160, USA.
Abstract:
We have established a novel role for the second messenger DAG (diacylglycerol), a product of PtdIns(4,5)P2 hydrolysis by PLC (phospholipase C). In addition to its well-known function as a protein kinase C activator, DAG produced by stimulation of the epidermal growth factor receptor causes the redistribution of the Rac-GAP (GTPase-activating protein) beta2-chimaerin to the plasma membrane, where it associates with the active form of Rac1 and promotes the inactivation of this small G-protein. This represents the first example of a Rac-GAP regulated directly by DAG in response to the activation of a tyrosine kinase receptor, and suggests a previously unappreciated role for this lipid as a negative modulator of Rac signalling.
Related Concept Videos
IP3/DAG Signaling Pathway
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Cell Polarization by Rho Proteins
Amplifying Signals via Enzymatic Cascade
Amplifying Signals via Second Messengers
What are Second Messengers?
