Cleaves glycosylphosphatidylinositol (GPI) and phosphatidylinositol (PI) anchors but not PI phosphates. Important factor in pathogenesis, PI-PLC activity is present only in virulent listeria species. It may participate in the lysis of the phagolysosomal membrane. a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol) = 1D-myo-inositol 1,2-cyclic phosphate + a 1,2-diacyl-sn-glycerol Monomer. Secreted and, to a lesser extent, cytoplasmic.