The phospholipase A2 superfamily and its group numbering system

The superfamily of phospholipase A2 (PLA2) enzymes currently consists of 15 Groups and many subgroups and includes five distinct types of enzymes, namely the secreted PLA2s (sPLA2), the cytosolic PLA2s (cPLA2), the Ca2+ independent PLA2s (iPLA2), the platelet-activating factor acetylhydrolases (PAF-AH), and the lysosomal PLA2s. In 1994, we established the systematic Group numbering system for these enzymes. Since then, the PLA2 superfamily has grown continuously and over the intervening years has required several updates of this Group numbering system. Since our last update, a number of new PLA2s have been discovered and are now included. Additionally, tools for the investigation of PLA2s and approaches for distinguishing between the different Groups are described.