Diacylglycerol kinase that converts diacylglycerol/DAG into phosphatidic acid/phosphatidate/PA and regulates the respective levels of these two bioactive lipids (PubMed:12810723, PubMed:23949095). 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 (Probable) (PubMed:12810723, PubMed:23949095). Plays a key role in promoting cell growth (PubMed:19710016). Activates the Ras/B-Raf/C-Raf/MEK/ERK signaling pathway induced by EGF (PubMed:19710016). Regulates the recruitment of RAF1 and BRAF from cytoplasm to membranes and their heterodimerization (PubMed:19710016). a 1,2-diacyl-sn-glycerol + ATP = a 1,2-diacyl-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. Interacts with RAF1 and BRAF. Homooligomers (PubMed:12810723). Heterooligomers (PubMed:12810723). Oligomerization through the SAM domain inhibits the diacylglycerol kinase activity (PubMed:12810723). Heterooligomerizes with SAM domain-containing isoforms of DGKD (PubMed:12810723). Does not form homooligomers. Translocated from the cytoplasm to endosomes in response to stress stimuli (PubMed:12810723). Isoform 2 is rapidly relocated back to the cytoplasm upon removal of stress stimuli, whereas isoform 1 exhibits sustained endosomal association (PubMed:12810723). Translocates from the cytoplasm to the cell membrane in the presence of active GTP-bound form of HRAS (PubMed:19710016). Expressed only in testis, kidney and colon. Ubiquitously expressed. Down-regulated by glucocorticoid. Up-regulated by glucocorticoid. The SAM domain mediates homooligomerization. Phosphorylated. Phosphorylation does not inhibit catalytic activity. Belongs to the eukaryotic diacylglycerol kinase family. Truncated N-terminus.