Function
P2X receptors are ATP-gated ion channels that play a role in intracellular calcium signaling. Not required for the purinergic response to extracellular nucleotides. Not essential for osmoregulation. Inward currents evoked by intracellular ATP. ATP analog beta, gamma-imido-ATP is a weak partial agonist of p2xE. Exclusively selective for ATP over other nucleotides. Insensitive to copper and P2 receptor antagonists PPADS and suramin but strongly inhibited by sodium ions. More permeable to ammonium than either sodium or potassium ions and less permeable to choline. Permeable to calcium ions, but not chloride.
Sequence
MNFRNIDWDSLFSYSTIKIVRIRDKRLGILHFAFLIGIILYIIVGTIFLQKKYLVLESPIGSIRTSLMAPSVKPTDLPYCLKNGTDTSYDGYPNKPCQYWDEYLVLYPPSEESSMFITTRCTQETQSTVNGCNLSEPTCVYNTTSSSDFYIANVENFTILLDHTLSAPSLGIQYNGAQLNGQLLDTDGNPMSLPPPNIVGVKGSPDIMSLQGVLTAAGVESLDSQGLANKSRTIRDDGILILCFITYSNTYTYNTGNYHYTYQFKLVQNTKYKIVEPVFTKDVEDRYIFDRHGVRIIFIQTGQLGQFDFQTMLLTFVSGIGLVTAASLIVDIIATRIMPQRSRYQELKFQDSSINNTQKTPTNDHTPLLKDNEDTINENSYQNNSYEK