FEBS Letters · 1997 · 92 citations · 11 references
Life SciencesMolecular BiologyPharmacologyCell SignalingElectrophysiologySignal TransductionIon Channel PhysiologyIon ChannelsIon PermeationMembrane ElectrophysiologyMembrane ReceptorsReceptor PhysiologyCellular Membrane PermeabilizationCurrentsHeterologous Expression SystemsMembrane PermeabilizationP2x7 Receptor SignalingPore Forming MechanismsPurinergic Receptor SignalingReceptors
The purinergic rP2X7 receptor expressed in a number of heterologous systems not only functions as a cation channel but also gives rise to a P2Z-like response, i.e. a reversible membrane permeabilization that allows the passage of molecules with molecular masses of > or = 300 Da. We investigated the properties of rP2X7 receptors expressed in Xenopus oocytes. In two-electrode voltage-clamp experiments, ATP or BzATP caused inward currents that were abolished or greatly diminished when NMDG+ or choline replaced Na+ as the principal external cation. In fluorescent dye experiments, BzATP application did not result in entry of the fluorophore YO-PRO-1(2+). Thus, rP2X7 expression in Xenopus oocytes does not by itself give rise to the pore-forming P2Z phenotype, suggesting that ancillary factors are involved.
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