Exhibits both phospholipase A1/2 and acyltransferase activities (PubMed:19615464, PubMed:22605381, PubMed:22825852, PubMed:26503625). Shows phospholipase A1 (PLA1) and A2 (PLA2), catalyzing the calcium-independent release of fatty acids from the sn-1 or sn-2 position of glycerophospholipids (PubMed:19615464, PubMed:22605381, PubMed:22825852). For most substrates, PLA1 activity is much higher than PLA2 activity (PubMed:19615464). Shows O- acyltransferase activity, catalyzing the transfer of a fatty acyl group from glycerophospholipid to the hydroxyl group of lysophospholipid (PubMed:19615464). Shows N-acyltransferase activity, catalyzing the calcium-independent transfer of a fatty acyl group at the sn-1 position of phosphatidylcholine (PC) and other glycerophospholipids to the primary amine of phosphatidylethanolamine (PE), forming N- acylphosphatidylethanolamine (NAPE), which serves as precursor for N- acylethanolamines (NAEs) (PubMed:19615464, PubMed:22605381, PubMed:22825852). {ECO:0000269|PubMed:19615464, ECO:0000269|PubMed:22605381, ECO:0000269|PubMed:22825852, ECO:0000303|PubMed:26503625}. This is the function of PLAAT4 (phospholipase A and acyltransferase 4, ENSG00000133321).