Nucleotides, the structural subunits of the nucleic acids, are also important extracellular signaling molecules. P2 receptors are a family of cell surface receptors that mediate a wide variety of physiologic effects in response to extracellular nucleotides. P2RX7 functions as a ligand-gated ion channel and is responsible for ATP-dependent lysis of macrophages through the formation of membrane pores permeable to large molecules.
