Catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides (PubMed:3356705). Thought to participate in the regulation of phospholipid metabolism in biomembranes including eicosanoid biosynthesis. Acts as a ligand for integrins. Binds to and activates integrins ITGAV:ITGB3, ITGA4:ITGB1 and ITGA5:ITGB1. Independent of its catalytic activity, activates integrins by binding to a site (site 2) which is distinct from the classical ligand-binding site (site 1) and inducing integrin conformational changes and enhanced ligand binding to site 1. Induces cell proliferation in an integrin-dependent manner (By similarity).