Enables ATP-dependent diacylglycerol kinase activity. Predicted to be involved in diacylglycerol metabolic process; intracellular signal transduction; and phosphatidic acid biosynthetic process. Predicted to be active in plasma membrane. Is expressed in several structures, including epithelial tube; ganglia; indirect flight muscle cell; larval midline neurons; and sensory nervous system primordium. Used to study glucose metabolism disease. Orthologous to several human genes including DGKB (diacylglycerol kinase beta).