Bhargava_2012_Br.J.Pharmacol_167_1301

Reference

Title : Allosteric nature of P2X receptor activation probed by photoaffinity labelling - Bhargava_2012_Br.J.Pharmacol_167_1301
Author(s) : Bhargava Y , Rettinger J , Mourot A
Ref : British Journal of Pharmacology , 167 :1301 , 2012
Abstract :

BACKGROUND AND PURPOSE: In P2X receptors, agonist binding at the interface between neighbouring subunits is efficiently transduced to ion channel gating. However, the relationship between binding and gating is difficult to study because agonists continuously bind and unbind. Here, we covalently incorporated agonists in the binding pocket of P2X receptors and examined how binding site occupancy affects the ability of the channel to gate. EXPERIMENTAL APPROACH: We used a strategy for tethering agonists to their ATP-binding pocket, while simultaneously probing ion channel gating using electrophysiology. The agonist 2',3'-O-(4-benzoylbenzoyl)-ATP (BzATP), a photoaffinity analogue of ATP, enabled us to trap rat homomeric P2X2 receptor and a P2X2/1 receptor chimera in different agonist-bound states. UV light was used to control the degree of covalent occupancy of the receptors. KEY
RESULTS: Irradiation of the P2X2/1 receptor chimera - BzATP complex resulted in a persistent current that lasted even after extensive washout, consistent with photochemical tethering of the agonist BzATP and trapping of the receptors in an open state. Partial labelling with BzATP primed subsequent agonist binding and modulated gating efficiency for both full and partial agonists. CONCLUSIONS AND IMPLICATIONS: Our photolabelling strategy provides new molecular insights into the activation mechanism of the P2X receptor. We show here that priming with full agonist molecules leads to an increase in gating efficiency after subsequent agonist binding.

PubMedSearch : Bhargava_2012_Br.J.Pharmacol_167_1301
PubMedID: 22725669

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Citations formats

Bhargava Y, Rettinger J, Mourot A (2012)
Allosteric nature of P2X receptor activation probed by photoaffinity labelling
British Journal of Pharmacology 167 :1301

Bhargava Y, Rettinger J, Mourot A (2012)
British Journal of Pharmacology 167 :1301