Membrane-bound diacylglycerol kinase that converts diacylglycerol/DAG into phosphatidic acid/phosphatidate/PA and regulates the respective levels of these two bioactive lipids (PubMed:11287665). Thereby, acts as a central switch between the signaling pathways activated by these second messengers with different cellular targets and opposite effects in numerous biological processes (PubMed:11287665). Also plays an important role in the biosynthesis of complex lipids (By similarity). Displays specificity for diacylglycerol substrates with an arachidonoyl acyl chain at the sn-2 position, with the highest activity toward 1-octadecanoyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycerol the main diacylglycerol intermediate within the phosphatidylinositol turnover cycle (PubMed:11287665, PubMed:19744926). Can also phosphorylate diacylglycerol substrates with a linoleoyl acyl chain at the sn-2 position but much less efficiently (By similarity). a 1,2-diacyl-sn-glycerol + ATP = a 1,2-diacyl-sn-glycero-3-phosphate + ADP + H(+) 1-hexadecanoyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycerol + ATP = 1-hexadecanoyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycero-3-phosphate + ADP + H(+) 1-octadecanoyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycerol + ATP = 1-octadecanoyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycero-3-phosphate + ADP + H(+) 1-eicosanoyl-2-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-sn-glycerol + ATP = 1-eicosanoyl-2-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-sn-glycero-3-phosphate + ADP + H(+) 1,2-di-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-sn-glycerol + ATP = 1,2-di-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-sn-glycero-3-phosphate + ADP + H(+) 1-octadecanoyl-2-(9Z,12Z)-octadecadienoyl-sn-glycerol + ATP = 1-octadecanoyl-2-(9Z,12Z-octadecadienoyl)-sn-glycero-3-phosphate + ADP + H(+) 1,2-di-(9Z,12Z-octadecadienoyl)-sn-glycerol + ATP = 1,2-di-(9Z,12Z-octadecadienoyl)-sn-glycero-3-phosphate + ADP + H(+) 1,2-di-(9Z-octadecenoyl)-sn-glycerol + ATP = 1,2-di-(9Z-octadecenoyl)-sn-glycero-3-phosphate + ADP + H(+) Lipid metabolism; glycerolipid metabolism. Highly expressed in brain and heart (PubMed:11287665). In brain, highly expressed in Purkinje cells of the cerebellum, pyramidal cells of the hippocampus, mitral cells of the olfactory bulb, and neurons of the substantia nigra (PubMed:11287665). Lower expression in neurons of the thalamus, superior olive, and lateral reticular nucleus is also detected (PubMed:11287665). Expressed in platelets (PubMed:23542698). Homozygous knockout mice are normal, reproduce and behave normally. No gross or histological abnormalities in major organs, including the brain are observed (PubMed:11287665). The phosphatidylinositol 4,5- bisphosphate-signaling pathway in cerebral cortex and long-term potentiation are affected (PubMed:11287665). Belongs to the eukaryotic diacylglycerol kinase family.