THE CYTOLYTIC P-2Z RECEPTOR FOR EXTRACELLULAR ATP IDENTIFIED AS A P-2X RECEPTOR (P2X(7))

The P-2Z receptor is responsible for adenosine triphosphate (ATP)-depe ndent lysis of macrophages through the formation of membrane pores per meable to large molecules. Other ATP-gated channels, the P-2X receptor s, are permeable only to small cations. Here, an ATP receptor, the P2X (7) receptor, was cloned from rat brain and exhibited both these prope rties. This protein is homologous to other P-2X receptors but has a un ique carboxyl-terminal domain that was required for the lytic actions of ATP. Thus, the P2X(7) (or P-2Z) receptor is a bifunctional molecule that could function in both fast synaptic transmission and the ATP-me diated lysis of antigen-presenting cells.