Structure and function of P2X receptors activated by extracellular ATP

ATP plays and important role in cellular signaling in many eukaryotic tissues. P2X receptors belong to a family of ligand-gated ion channels with ATP as naturally occurring ligand. They are responsible for many different physiological functions in organisms. There are several studies published in last 11 years about crystalization and structure of P2X receptors. These studies shed light on many phenomena regarding P2X receptors such as ligand binding, several types of modulation, characterization of P2X ion channel and mainly the overall structure of P2X receptors and unique structural elements of different P2X subtypes. These studies also help to explain reasons of P2X receptor desenzitization, mechanism of ion channel opening and conformational changes induced by ligand binding, a prerequisite of channel opening. The aim of this work is to summarize current knowledge about structures of P2X receptors. Key words: P2X receptor, purinergic signaling, ATP, ion channel, crystal structur