Acyltransferase which catalyzes the transfert of an acyl group from an acyl-CoA to a lysophosphatidylinositol (1-acylglycerophosphatidylinositol or LPI) leading to the production of a phosphatidylinositol (1,2-diacyl-sn-glycero-3-phosphoinositol or PI) and participates in the reacylation step of the phospholipid remodeling pathway also known as the Lands cycle (PubMed:18772128, PubMed:18094042). Prefers arachidonoyl-CoA as the acyl donor, thus contributing to the regulation of free levels arachidonic acid in cell (PubMed:18772128, PubMed:18094042). In liver, participates in the regulation of triglyceride metabolism through the phosphatidylinositol acyl-chain remodeling regulation (PubMed:32253259). (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + a 1-acyl-sn-glycero-3-phospho-(1D-myo-inositol) = a 1-acyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycero-3-phospho-(1D-myo-inositol) + CoA (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + 1-hexadecanoyl-sn-glycero-3-phosphocholine = 1-hexadecanoyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycero-3-phosphocholine + CoA a 1-acyl-sn-glycero-3-phospho-(1D-myo-inositol) + an acyl-CoA = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol) + CoA (5Z,8Z,11Z,14Z)-eicosatetraenoyl-CoA + 1-octadecanoyl-sn-glycero-3-phospho-(1D-myo-inositol) = 1-octadecanoyl-2-(5Z,8Z,11Z,14Z-eicosatetraenoyl)-sn-glycero-3-phospho-(1D-myo-inositol) + CoA Activity is inhibited by thimerosal. Lipid metabolism; phospholipid metabolism. Interacts with SPTSSA; the interaction facilitates MBOAT7 location to mitochondria-associated membranes (MAMs). Localized in specific membrane structures termed mitochondria-associated membranes (MAMs) which connect the endoplasmic reticulum (ER) and the mitochondria. Overexpressed in metastatic breast and bladder carcinomas relative to normal breast epithelium and urothelium. The disease is caused by variants affecting the gene represented in this entry. Belongs to the membrane-bound acyltransferase family.