Specifically catalyzes coenzyme A (CoA)-dependent acylation of 1-acyl-sn-glycerol 3-phosphate (2-lysophosphatidic acid/LPA) to generate phosphatidic acid (PA), an important metabolic intermediate and precursor for both triglycerides and glycerophospholipids. Does not esterify other lysophospholipids. Acyl donors are long chain (at least C16) fatty acyl-CoAs: arachidonoyl-CoA, linoleoyl-CoA, oleoyl-CoA and at a lesser extent palmitoyl-CoA (PubMed:22560221). Additionally possesses low triacylglycerol lipase and CoA-independent acylglycerol transacylase activities and thus may play a role in acyl-chain remodeling of triglycerides (PubMed:15364929, PubMed:20034933, PubMed:22560221). Has hydrolytic activity against glycerolipids triacylglycerol, diacylglycerol and monoacylglycerol, with a strong preference for oleic acid as the acyl moiety (PubMed:21878620). Possesses phospholipase A2 activity (PubMed:15364929). a 1-acyl-sn-glycero-3-phosphate + an acyl-CoA = a 1,2-diacyl-sn-glycero-3-phosphate + CoA a triacylglycerol + H2O = a diacylglycerol + a fatty acid + H(+) a 1,3-diacylglycerol + a 1-acylglycerol = a triacylglycerol + glycerol a 1,2-diacylglycerol + a 1-acylglycerol = a triacylglycerol + glycerol 2 a 1-acylglycerol = a 1,2-diacylglycerol + glycerol (9Z)-octadecenoyl-CoA + 1-(9Z-octadecenoyl)-sn-glycero-3-phosphate = 1,2-di-(9Z-octadecenoyl)-sn-glycero-3-phosphate + CoA 1-(9Z-octadecenoyl)-sn-glycero-3-phosphate + hexadecanoyl-CoA = 1-(9Z)-octadecenoyl-2-hexadecanoyl-sn-glycero-3-phosphate + CoA (9Z,12Z)-octadecadienoyl-CoA + 1-(9Z-octadecenoyl)-sn-glycero-3-phosphate = 1-(9Z)-octadecenoyl-2-(9Z,12Z)-octadecadienoyl-sn-glycero-3-phosphate + CoA (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + 1-(9Z-octadecenoyl)-sn-glycero-3-phosphate = 1-(9Z)-octadecenoyl-2-(5Z,8Z,11Z,14Z)-eicosatetraenoyl-sn-glycero-3-phosphate + CoA 2 1-(9Z-octadecenoyl)-glycerol = 1,2-di-(9Z-octadecenoyl)-glycerol + glycerol 1,2-di-(9Z-octadecenoyl)-glycerol + 1-(9Z-octadecenoyl)-glycerol = 1,2,3-tri-(9Z-octadecenoyl)-glycerol + glycerol 1,3-di-(9Z-octadecenoyl)-glycerol + 1-(9Z-octadecenoyl)-glycerol = 1,2,3-tri-(9Z-octadecenoyl)-glycerol + glycerol 1,2,3-tri-(9Z-octadecenoyl)-glycerol + H2O = (9Z)-octadecenoate + 1,3-di-(9Z-octadecenoyl)-glycerol + H(+) a 1,2-diacyl-sn-glycero-3-phosphocholine + H2O = a 1-acyl-sn-glycero-3-phosphocholine + a fatty acid + H(+) The triglyceride lipase activity is inhibited by BEL ((E)-6-(bromomethylene)-3-(1-naphthalenyl)-2H-tetrahydropyran-2-one), a suicide substrate inhibitor. Phospholipid metabolism. Glycerolipid metabolism. By changes in energy balance: down-regulated following very low-calorie diet, whereas refeeding elevates the mRNA level. Polymorphic variation at position 148 influences insulin secretion levels and obesity. In obese subjects the body mass index and waist are higher in carriers of the Ile-148 allele. The Ile-148 carriers also display decreased insulin secretion in response to oral glucose tolerance test. Met-148 allele carriers are seemingly more insulin resistant at a lower body mass index. Disease susceptibility is associated with variants affecting the gene represented in this entry. Variant Met-148 was initially reported to reduce triglyceride hydrolysis activity in vitro (PubMed:20034933, PubMed:21878620). However further in vitro and in vivo data demonstrated that it actually does not affect triglyceride hydrolysis activity, but rather increases 1-acylglycerol-3-phosphate O-acyltransferase activity (PubMed:22560221).