Diacylglycerol kinase that converts diacylglycerol/DAG into phosphatidic acid/phosphatidate/PA and regulates the respective levels of these two bioactive lipids (PubMed:27643686). 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). Plays a key role in promoting cell growth. Activates the Ras/B-Raf/C-Raf/MEK/ERK signaling pathway induced by EGF. Regulates the recruitment of RAF1 and BRAF from cytoplasm to membranes and their heterodimerization (By similarity). 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. Heterooligomers. Oligomerization through the SAM domain inhibits the diacylglycerol kinase activity. Heterooligomerizes with SAM domain-containing isoforms of DGKD. Does not form homooligomers. Translocated from the cytoplasm to endosomes in response to stress stimuli. Isoform 2 is rapidly relocated back to the cytoplasm upon removal of stress stimuli, whereas isoform 1 exhibits sustained endosomal association. Translocates from the cytoplasm to the cell membrane in the presence of active GTP-bound form of HRAS. Widely expressed (PubMed:27643686). Detected in the granulosa cells of the primary and secondary follicles (PubMed:25613821). Expressed in mature follicles and corpus lutea (PubMed:25613821). Expressed in the oviductal epithelium (PubMed:25613821). In the uterus, strongly expressed in the luminal epithelium (PubMed:25613821). Detected in the uterine glands (PubMed:25613821). Detected in ovary and uterus (at protein level). Specifically expressed in testis (PubMed:25613821, PubMed:27643686). Detected in the inner area of the testis (PubMed:25613821). Strongly expressed in the secondary spermatocytes and the round spermatids and weakly detected in the primary spermatocytes (PubMed:25613821). The SAM domain mediates homooligomerization. Phosphorylated. Phosphorylation does not inhibit catalytic activity. Belongs to the eukaryotic diacylglycerol kinase family.