Acts as a magnesium-dependent phosphatidate phosphatase enzyme which catalyzes the conversion of phosphatidic acid to diacylglycerol during triglyceride, phosphatidylcholine and phosphatidylethanolamine biosynthesis in the reticulum endoplasmic membrane. Plays important roles in controlling the metabolism of fatty acids at different levels. Acts also as a nuclear transcriptional coactivator for PPARGC1A to modulate lipid metabolism. a 1,2-diacyl-sn-glycero-3-phosphate + H2O = a 1,2-diacyl-sn-glycerol + phosphate Inhibited by N-ethylmaleimide. Translocates to endoplasmic reticulum membrane with increasing levels of oleate. Expressed in liver, lung, kidney, placenta, spleen, thymus, lymph node, prostate, testes, small intestine, and colon. Contains 1 Asp-Xaa-Asp-Xaa-Thr (DXDXT) motif, a catalytic motif known to be essential for phosphatidate phosphatase activity. Contains one Leu-Xaa-Xaa-Ile-Leu (LXXIL) motif, a motif known to be a transcriptional binding motif. The disease is caused by variants affecting the gene represented in this entry. Belongs to the lipin family. Repertory of FMF and hereditary autoinflammatory disorders mutations