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Pflugers Arch
2006 Mar 01;4516:776-92. doi: 10.1007/s00424-005-1515-2.
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Allosteric effects of external K+ ions mediated by the aspartate of the GYGD signature sequence in the Kv2.1 K+ channel.
Chapman ML, Blanke ML, Krovetz HS, VanDongen AM.
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K+ channels achieve exquisite ion selectivity without jeopardizing efficient permeation by employing multiple, interacting K+-binding sites. Introduction ofa cadmium (Cd2+)-binding site in the external vestibule of Kv2.1 (drk1), allowed us to functionally characterize a binding site for external monovalent cations. Permeant ions displayed higher affinity for this site than non-permeant monovalent cations, although the selectivity profile was different from that of the channel. Point mutations identified the highly conserved aspartate residue immediately following the selectivity filter as a critical determinant of the antagonism between external K+ and Cd2+ ions. A conservative mutation at this position (D378E) significantly affected the open-state stability. Moreover, the mean open time was found to be modulated by external K+ concentration, suggesting a coupling between channel closing and the permeation process. Reducing the Rb+ conductance by mutating the selectivity filter to the sequence found inKv4.1, also significantly reduced the effectiveness ofRb+ ions to antagonize Cd2+ inhibition, thereby implicating the selectivity filter as the site at which K+ions exert their antagonistic effect on Cd2+ block. The equivalent of D378 in KcsA, D80, takes part in an inter-subunit hydrogen-bond network that allows D80to functionally interact with the selectivity filter. The results suggest that external K+ ions antagonize Cd2+inhibition (in I379C) and modulate the mean open time(in the wild-type Kv2.1) by altering the occupancy profile of the K+-binding sites in the selectivity filter.
Andalib,
Control of outer vestibule dynamics and current magnitude in the Kv2.1 potassium channel.
2002, Pubmed
Andalib,
Control of outer vestibule dynamics and current magnitude in the Kv2.1 potassium channel.
2002,
Pubmed Baukrowitz,
Modulation of K+ current by frequency and external [K+]: a tale of two inactivation mechanisms.
1995,
Pubmed Bezanilla,
The voltage sensor in voltage-dependent ion channels.
2000,
Pubmed Capener,
Filter flexibility in a mammalian K channel: models and simulations of Kir6.2 mutants.
2003,
Pubmed Capener,
Homology modeling and molecular dynamics simulation studies of an inward rectifier potassium channel.
2000,
Pubmed Chapman,
Activation-dependent subconductance levels in the drk1 K channel suggest a subunit basis for ion permeation and gating.
1997,
Pubmed
,
Xenbase Chapman,
GYGD pore motifs in neighbouring potassium channel subunits interact to determine ion selectivity.
2001,
Pubmed Chen,
Allosteric effects of permeating cations on gating currents during K+ channel deactivation.
1997,
Pubmed Choi,
Tetraethylammonium blockade distinguishes two inactivation mechanisms in voltage-activated K+ channels.
1991,
Pubmed Clay,
Effects of permeant cations on K+ channel gating in nerve axons revisited.
1996,
Pubmed Consiglio,
Influence of pore residues on permeation properties in the Kv2.1 potassium channel. Evidence for a selective functional interaction of K+ with the outer vestibule.
2003,
Pubmed del Camino,
Blocker protection in the pore of a voltage-gated K+ channel and its structural implications.
2000,
Pubmed Demo,
Ion effects on gating of the Ca(2+)-activated K+ channel correlate with occupancy of the pore.
1992,
Pubmed Doyle,
The structure of the potassium channel: molecular basis of K+ conduction and selectivity.
1998,
Pubmed Doyle,
Crystal structures of a complexed and peptide-free membrane protein-binding domain: molecular basis of peptide recognition by PDZ.
1996,
Pubmed Ehlert,
Estimation of the affinities of allosteric ligands using radioligand binding and pharmacological null methods.
1988,
Pubmed Ferguson,
Opening and closing transitions for BK channels often occur in two steps via sojourns through a brief lifetime subconductance state.
1993,
Pubmed Friedman,
The role of small intraprotein cavities in the catalytic cycle of bacteriorhodopsin.
2003,
Pubmed Gómez-Lagunas,
The relation between ion permeation and recovery from inactivation of ShakerB K+ channels.
1994,
Pubmed Harris,
A permanent ion binding site located between two gates of the Shaker K+ channel.
1998,
Pubmed
,
Xenbase Hartmann,
Exchange of conduction pathways between two related K+ channels.
1991,
Pubmed
,
Xenbase HODGKIN,
A quantitative description of membrane current and its application to conduction and excitation in nerve.
1952,
Pubmed Holmgren,
The activation gate of a voltage-gated K+ channel can be trapped in the open state by an intersubunit metal bridge.
1998,
Pubmed Hurst,
Molecular determinants of external barium block in Shaker potassium channels.
1996,
Pubmed
,
Xenbase Hurst,
External barium influences the gating charge movement of Shaker potassium channels.
1997,
Pubmed
,
Xenbase Ikeda,
Influence of permeating ions on potassium channel block by external tetraethylammonium.
1995,
Pubmed Immke,
Potassium-dependent changes in the conformation of the Kv2.1 potassium channel pore.
1999,
Pubmed Immke,
Ion-Ion interactions at the selectivity filter. Evidence from K(+)-dependent modulation of tetraethylammonium efficacy in Kv2.1 potassium channels.
2000,
Pubmed Jarolimek,
The selectivity of different external binding sites for quaternary ammonium ions in cloned potassium channels.
1995,
Pubmed
,
Xenbase Jiang,
X-ray structure of a voltage-dependent K+ channel.
2003,
Pubmed Jiang,
Crystal structure and mechanism of a calcium-gated potassium channel.
2002,
Pubmed Kiss,
Contribution of the selectivity filter to inactivation in potassium channels.
1999,
Pubmed Kiss,
Modulation of C-type inactivation by K+ at the potassium channel selectivity filter.
1998,
Pubmed Krovetz,
Atomic distance estimates from disulfides and high-affinity metal-binding sites in a K+ channel pore.
1997,
Pubmed Kuo,
Crystal structure of the potassium channel KirBac1.1 in the closed state.
2003,
Pubmed Larsson,
Transmembrane movement of the shaker K+ channel S4.
1996,
Pubmed
,
Xenbase Levy,
Recovery from C-type inactivation is modulated by extracellular potassium.
1996,
Pubmed Liu,
Gated access to the pore of a voltage-dependent K+ channel.
1997,
Pubmed Logothetis,
Incremental reductions of positive charge within the S4 region of a voltage-gated K+ channel result in corresponding decreases in gating charge.
1992,
Pubmed
,
Xenbase López-Barneo,
Effects of external cations and mutations in the pore region on C-type inactivation of Shaker potassium channels.
1993,
Pubmed
,
Xenbase Lu,
Probing ion permeation and gating in a K+ channel with backbone mutations in the selectivity filter.
2001,
Pubmed
,
Xenbase MacKinnon,
New insights into the structure and function of potassium channels.
1991,
Pubmed MacKinnon,
Mutations affecting TEA blockade and ion permeation in voltage-activated K+ channels.
1990,
Pubmed Molina,
Pore mutations in Shaker K+ channels distinguish between the sites of tetraethylammonium blockade and C-type inactivation.
1997,
Pubmed Papazian,
Alteration of voltage-dependence of Shaker potassium channel by mutations in the S4 sequence.
1991,
Pubmed
,
Xenbase Pardo,
Extracellular K+ specifically modulates a rat brain K+ channel.
1992,
Pubmed
,
Xenbase Pennefather,
A scheme to account for the effects of Rb+ and K+ on inward rectifier K channels of bovine artery endothelial cells.
1994,
Pubmed Perozo,
Structural rearrangements underlying K+-channel activation gating.
1999,
Pubmed Perozo,
Three-dimensional architecture and gating mechanism of a K+ channel studied by EPR spectroscopy.
1998,
Pubmed Rosenmund,
The tetrameric structure of a glutamate receptor channel.
1998,
Pubmed Sarkar,
The "megaprimer" method of site-directed mutagenesis.
1990,
Pubmed Schneggenburger,
Coupling of permeation and gating in an NMDA-channel pore mutant.
1997,
Pubmed
,
Xenbase Shapiro,
Permeant ion effects on the gating kinetics of the type L potassium channel in mouse lymphocytes.
1991,
Pubmed Sigworth,
Data transformations for improved display and fitting of single-channel dwell time histograms.
1987,
Pubmed Spassova,
Tuning the voltage dependence of tetraethylammonium block with permeant ions in an inward-rectifier K+ channel.
1999,
Pubmed
,
Xenbase Starkus,
Ion conduction through C-type inactivated Shaker channels.
1997,
Pubmed
,
Xenbase Swenson,
K+ channels close more slowly in the presence of external K+ and Rb+.
1981,
Pubmed Taylor,
Conductance and kinetics of single cGMP-activated channels in salamander rod outer segments.
1995,
Pubmed Thompson,
External TEA block of shaker K+ channels is coupled to the movement of K+ ions within the selectivity filter.
2003,
Pubmed
,
Xenbase Valiyaveetil,
Glycine as a D-amino acid surrogate in the K(+)-selectivity filter.
2004,
Pubmed VanDongen,
K channel gating by an affinity-switching selectivity filter.
2004,
Pubmed VanDongen,
A new algorithm for idealizing single ion channel data containing multiple unknown conductance levels.
1996,
Pubmed VanDongen,
Alteration and restoration of K+ channel function by deletions at the N- and C-termini.
1990,
Pubmed Woodhull,
Ionic blockage of sodium channels in nerve.
1973,
Pubmed Yang,
Molecular basis of charge movement in voltage-gated sodium channels.
1996,
Pubmed Yang,
How does the W434F mutation block current in Shaker potassium channels?
1997,
Pubmed
,
Xenbase Yellen,
Premonitions of ion channel gating.
1998,
Pubmed Yellen,
Mutations affecting internal TEA blockade identify the probable pore-forming region of a K+ channel.
1991,
Pubmed Yool,
Alteration of ionic selectivity of a K+ channel by mutation of the H5 region.
1991,
Pubmed
,
Xenbase Zheng,
Intermediate conductances during deactivation of heteromultimeric Shaker potassium channels.
1998,
Pubmed
,
Xenbase Zheng,
Selectivity changes during activation of mutant Shaker potassium channels.
1997,
Pubmed
,
Xenbase Zhou,
The occupancy of ions in the K+ selectivity filter: charge balance and coupling of ion binding to a protein conformational change underlie high conduction rates.
2003,
Pubmed Zhou,
Chemistry of ion coordination and hydration revealed by a K+ channel-Fab complex at 2.0 A resolution.
2001,
Pubmed
