Diglyceride

A diglyceride, or diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages.

Although inositol trisphosphate diffuses into the cytosol, diacylglycerol remains within the plasma membrane, due to its hydrophobic properties.

IP3 stimulates the release of calcium ions from the smooth endoplasmic reticulum, whereas DAG is a physiological activator of protein kinase C (PKC).

Diacylglycerol has been shown to exert some of its excitatory actions on vesicle release through interactions with the presynaptic priming protein family Munc13.

Binding of DAG to the C1 domain of Munc13 increases the fusion competence of synaptic vesicles resulting in potentiated release.