Sequentially removes both fatty acyl groups from diacylglycerophospholipids and therefore has both phospholipase A and lysophospholipase activities. Substrate preference is phosphatidylserine > phosphatidylinositol. Does not cleave phosphatidylcholine, phosphatidylethanolamine, phosphatidic acid and phosphatidylinositol-bisphosphate (PubMed:10497163). Mainly responsible for the degradation of phosphatidylinositol in vivo (PubMed:15588231). a 1-acyl-sn-glycero-3-phosphocholine + H2O = a fatty acid + H(+) + sn-glycerol 3-phosphocholine Belongs to the lysophospholipase family.