Abstract
Diacylglycerol (DAG) is a bioactive lipid with diverse biological roles. DAG transiently accumulates in a membrane upon receipt of an appropriate stimulus that activates phospholipase C to cleave phospholipids. The resulting hydrolysis product DAG binds to proteins such as protein kinase C to initiate a variety of downstream cellular processes. DAG kinases attenuate such responses by converting DAG to phosphatidic acid. This protocol describes an assay designed to quantify cellular DAG levels. The assay exploits the enzymatic conversion of DAG (sn-1,2-diacylglycerol) to phosphatidic acid (1,2-diacyl- sn-glycerol-3-phosphate) in conjunction with the incorporation of a radiolabeled phosphate group by DAG kinase (Figure 1). This assay was described in (Strijbis et al., 2013).