ATP, the intracellular energy source, is also an extremely important cell-cell signalling molecule for a wide variety of cells across evolutionarily diverse organisms. The extracellular biochemistry of ATP and its derivatives is complex, and the multiple membrane receptors that it activates are linked to many intracellular signalling systems. Purinergic signalling affects a diverse range of cellular phenomena, including ion channel function, cytoskeletal dynamics, gene expression, secretion, cell proliferation, differentiation and cell death. Recently, this class of signalling molecules and |