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J Physiol
2009 Dec 15;587Pt 24:5801-18. doi: 10.1113/jphysiol.2009.182824.
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Functional and structural identification of amino acid residues of the P2X2 receptor channel critical for the voltage- and [ATP]-dependent gating.
Keceli B
,
Kubo Y
.
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The extracellular ATP-gated cation channel P2X(2) is known to show voltage-dependent gating in spite of the absence of a canonical voltage sensor domain. We previously observed that the hyperpolarization-evoked activation of P2X(2) at the steady state in the presence of ATP varied depending on [ATP]. With increasing [ATP], the conductance-voltage (G-V) relationship shifted to more depolarized potentials and the activation kinetics were accelerated. Using a three-state model consisting of an ATP binding step and a rate limiting gating step, we successfully reproduced the voltage-dependent gating including its [ATP] dependence. In this study, in order to identify the structural basis of voltage and ATP dependence, we analysed various mutants in the Xenopus oocyte expression system under two-electrode voltage clamp. In the ATP binding region mutant K308R, the G-V relationship was shifted towards more hyperpolarized potentials, there was no clear [ATP] dependence, and activation was faster than in wild-type (WT). These results could be simulated by assuming an increase in the off rate of the gating step, in addition to changes in the ATP binding step. With F44C mutation in the 1st transmembrane (TM) region (TM1) or T339S in TM2, activation in low [ATP] was slow and the channel was constitutively active at all membrane potentials in high [ATP]. These results could be simulated by reducing the off rate of the gating step. Phenotypes of the double mutants, K308R/F44C and K308R/T339S, were similar to WT, suggesting that TM and ATP binding region mutants offset the effect of each other. Analysis of the effects on WT of two other agonists, ADP and AP(4)A, revealed that the electrostatic charge is not the sole critical factor. Taking these results together with the recently reported crystal structure, it was suggested that upon binding of ATP, the occupied binding site indirectly interacts with the extracellular end of the TM regions to trigger conformational changes for gating in a voltage-dependent manner.
Arnold,
The SWISS-MODEL workspace: a web-based environment for protein structure homology modelling.
2006, Pubmed
Arnold,
The SWISS-MODEL workspace: a web-based environment for protein structure homology modelling.
2006,
Pubmed
Aschrafi,
Trimeric architecture of homomeric P2X2 and heteromeric P2X1+2 receptor subtypes.
2004,
Pubmed
,
Xenbase
Barrera,
Atomic force microscopy imaging demonstrates that P2X2 receptors are trimers but that P2X6 receptor subunits do not oligomerize.
2005,
Pubmed
Ben-Chaim,
Movement of 'gating charge' is coupled to ligand binding in a G-protein-coupled receptor.
2006,
Pubmed
,
Xenbase
Bordoli,
Protein structure homology modeling using SWISS-MODEL workspace.
2009,
Pubmed
Brake,
New structural motif for ligand-gated ion channels defined by an ionotropic ATP receptor.
1994,
Pubmed
,
Xenbase
Burnstock,
Purine and pyrimidine receptors.
2007,
Pubmed
Cao,
Thr339-to-serine substitution in rat P2X2 receptor second transmembrane domain causes constitutive opening and indicates a gating role for Lys308.
2007,
Pubmed
Charnet,
Pharmacological and kinetic properties of alpha 4 beta 2 neuronal nicotinic acetylcholine receptors expressed in Xenopus oocytes.
1992,
Pubmed
,
Xenbase
Ding,
Single channel properties of P2X2 purinoceptors.
1999,
Pubmed
,
Xenbase
Domene,
Role of aromatic localization in the gating process of a potassium channel.
2006,
Pubmed
Egan,
A domain contributing to the ion channel of ATP-gated P2X2 receptors identified by the substituted cysteine accessibility method.
1998,
Pubmed
Ennion,
The role of positively charged amino acids in ATP recognition by human P2X(1) receptors.
2000,
Pubmed
,
Xenbase
Figl,
Voltage-jump relaxation kinetics for wild-type and chimeric beta subunits of neuronal nicotinic receptors.
1996,
Pubmed
,
Xenbase
Fujiwara,
Density-dependent changes of the pore properties of the P2X2 receptor channel.
2004,
Pubmed
,
Xenbase
Fujiwara,
Voltage- and [ATP]-dependent gating of the P2X(2) ATP receptor channel.
2009,
Pubmed
,
Xenbase
Fujiwara,
Regulation of the desensitization and ion selectivity of ATP-gated P2X2 channels by phosphoinositides.
2006,
Pubmed
,
Xenbase
Gever,
Pharmacology of P2X channels.
2006,
Pubmed
Jiang,
Amino acid residues involved in gating identified in the first membrane-spanning domain of the rat P2X(2) receptor.
2001,
Pubmed
Jiang,
Identification of amino acid residues contributing to the ATP-binding site of a purinergic P2X receptor.
2000,
Pubmed
Jiang,
Subunit arrangement in P2X receptors.
2003,
Pubmed
Jindrichova,
Functional relevance of aromatic residues in the first transmembrane domain of P2X receptors.
2009,
Pubmed
Kawate,
Crystal structure of the ATP-gated P2X(4) ion channel in the closed state.
2009,
Pubmed
Khakh,
Molecular physiology of P2X receptors and ATP signalling at synapses.
2001,
Pubmed
Khakh,
Contribution of transmembrane regions to ATP-gated P2X2 channel permeability dynamics.
2005,
Pubmed
Koizumi,
Regulation of cell-to-cell communication mediated by astrocytic ATP in the CNS.
2005,
Pubmed
Lester,
Cys-loop receptors: new twists and turns.
2004,
Pubmed
Li,
Gain and loss of channel function by alanine substitutions in the transmembrane segments of the rat ATP-gated P2X2 receptor.
2004,
Pubmed
Li,
Interaction of the aromatics Tyr-72/Trp-288 in the interface of the extracellular and transmembrane domains is essential for proton gating of acid-sensing ion channels.
2009,
Pubmed
,
Xenbase
Marquez-Klaka,
Identification of an intersubunit cross-link between substituted cysteine residues located in the putative ATP binding site of the P2X1 receptor.
2007,
Pubmed
,
Xenbase
Mio,
Reconstruction of the P2X(2) receptor reveals a vase-shaped structure with lateral tunnels above the membrane.
2009,
Pubmed
Miyazawa,
Structure and gating mechanism of the acetylcholine receptor pore.
2003,
Pubmed
Nakazawa,
Voltage-dependent gating of ATP-activated channels in PC12 cells.
1997,
Pubmed
Nakazawa,
Characterization of voltage-dependent gating of P2X2 receptor/channel.
2005,
Pubmed
,
Xenbase
Nicke,
P2X1 and P2X3 receptors form stable trimers: a novel structural motif of ligand-gated ion channels.
1998,
Pubmed
,
Xenbase
North,
Molecular physiology of P2X receptors.
2002,
Pubmed
Ohana,
The metabotropic glutamate G-protein-coupled receptors mGluR3 and mGluR1a are voltage-sensitive.
2006,
Pubmed
,
Xenbase
Rassendren,
Identification of amino acid residues contributing to the pore of a P2X receptor.
1997,
Pubmed
Roberts,
Molecular properties of P2X receptors.
2006,
Pubmed
Roberts,
Cysteine substitution mutants give structural insight and identify ATP binding and activation sites at P2X receptors.
2007,
Pubmed
,
Xenbase
Samways,
On the role of the first transmembrane domain in cation permeability and flux of the ATP-gated P2X2 receptor.
2008,
Pubmed
Silberberg,
Secondary structure and gating rearrangements of transmembrane segments in rat P2X4 receptor channels.
2005,
Pubmed
,
Xenbase
Silberberg,
Ivermectin Interaction with transmembrane helices reveals widespread rearrangements during opening of P2X receptor channels.
2007,
Pubmed
,
Xenbase
Stoop,
Contribution of individual subunits to the multimeric P2X(2) receptor: estimates based on methanethiosulfonate block at T336C.
1999,
Pubmed
,
Xenbase
Surprenant,
Signaling at purinergic P2X receptors.
2009,
Pubmed
Torres,
Topological analysis of the ATP-gated ionotropic [correction of ionotrophic] P2X2 receptor subunit.
1998,
Pubmed
Valera,
A new class of ligand-gated ion channel defined by P2x receptor for extracellular ATP.
1994,
Pubmed
,
Xenbase
Wildman,
Selectivity of diadenosine polyphosphates for rat P2X receptor subunits.
1999,
Pubmed
,
Xenbase
Yan,
Participation of the Lys313-Ile333 sequence of the purinergic P2X4 receptor in agonist binding and transduction of signals to the channel gate.
2006,
Pubmed
Zhou,
Yeast screens show aromatic residues at the end of the sixth helix anchor transient receptor potential channel gate.
2007,
Pubmed
Zhou,
Two mechanisms for inward rectification of current flow through the purinoceptor P2X2 class of ATP-gated channels.
1998,
Pubmed
,
Xenbase
