In biochemical signaling, diacylglycerol (DAG) functions as a second messenger signaling lipid, and is a product of the hydrolysis of the phospholipid PIP2 (phosphatidylinositolbisphosphate) by the enzyme phospholipase C (PLC) (a membrane-bound enzyme) that, through the same reaction, produces inositol trisphosphate (IP3). Although inositol trisphosphate (IP3) diffuses into the cytosol, DAG 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). The production of DAG in the membrane facilitates translocation of PKC from the cytosol to the plasma membrane. (See References)
Diacylglycerol mimicks the effects of the tumor-promoting compounds phorbol esters.
Since short chain Diacylglycerols mimic effects of the tumor-promoting phorbol diesters in a number of biological systems, extra care should be employed in their handling. Treatment of solutions, vessels and other articles with 1N NaOH before washing or discarding will destroy diacylglycerols.
Diacylglycerols are conveniently stored in chloroform solutions in glass vials with teflon-lined caps at -20°C. Under these conditions acyl migration is minimal. Avoid plastic when handling chloroform solutions.
Delivery to cells:
Dry samples of diacylglycerol in chloroform, using a stream of nitrogen. Dissolve the residue in an appropriate volume of ethanol or DMSO, then dilute to the desired aqueous medium.
Most biological responses saturate at 20 to 250 µM sn-1,2-dioctanoylglycerol. Only sn-1,2 isomers appear to be active.
Ebeling, J.G., Vandenbark, G.R., Kuhn, L., Ganong, B., Bell, R.M. & Niedel, J.E. (1985) Diacylglycerols and Phorbol Diesters Induce Leukemic Cell Differentiation via a Common Mechanism. Proc. Natl. Acad. Sci. USA 82:815-819.
Davis, R.J., Ganong, B.R., Bell, R.M. & Czech, M.P. (1985) sn-1,2-dioctanoylglycerol: a Cell Permeable Diacylglycerol That Mimics Phorbol Diester Action on the Epidermal Growth Factor Receptor and Mitogenesis. J. Biol. Chem. 260:1562-1566.
Lapetina, E.G., Reep, B., Ganong, B.R. & Bell, R.M. (1985) Exogenous sn-1,2-diacylglycerols Containing Saturated Fatty Acids Functions as Bioregulators of Protein Kinase C in Human Platelets. J. Biol. Chem. 260:1358-1361.
Ganong, B.R., Loomis, C.R., Hannun, Y.A. & Bell, R.M. (1986) Specificity and Mechanism of Protein Kinase C Activation by sn-1,2-diacylglycerols. Proc. Natl. Acad. Sci. USA 83:1184-1188.