The role of the P2X7 receptor in the retina: Cell signalling and dysfunction

Abstract

Adenosine 5′-triphosphate (ATP) acts as a signalling molecule within the retina. It can be released like a traditional neurotransmitter via exocytosis, but non-classical mechanisms for release have also been demonstrated. ATP and its breakdown products act at a range of purine receptor subclasses, P1, P2X and P2Y, which are expressed by all cell types of the retina. The P2X-receptors are ligand-gated ion channels and seven subclasses (P2X1-7) have been identified. In particular, the P2X7 receptor subclass is unique; it is relatively insensitive to ATP and it has a long intracellular C-terminus, which is not only critical for ion channel function, but also allows the formation of a pore in th..