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Control of ion conduction in L-type Ca2+ channels by the concerted action of S5-6 regions.
Cibulsky SM
,
Sather WA
.
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Voltage-gated L-type Ca(2+) channels from cardiac (alpha(1C)) and skeletal (alpha(1S)) muscle differ from one another in ion selectivity and permeation properties, including unitary conductance. In 110 mM Ba(2+), unitary conductance of alpha(1S) is approximately half that of alpha(1C). As a step toward understanding the mechanism of rapid ion flux through these highly selective ion channels, we used chimeras constructed between alpha(1C) and alpha(1S) to identify structural features responsible for the difference in conductance. Combined replacement of the four pore-lining P-loops in alpha(1C) with P-loops from alpha(1S) reduced unitary conductance to a value intermediate between those of the two parent channels. Combined replacement of four larger regions that include sequences flanking the P-loops (S5 and S6 segments along with the P-loop-containing linker between these segments (S5-6)) conferred alpha(1S)-like conductance on alpha(1C). Likewise, substitution of the four S5-6 regions of alpha(1C) into alpha(1S) conferred alpha(1C)-like conductance on alpha(1S). These results indicate that, comparing alpha(1C) with alpha(1S), the differences in structure that are responsible for the difference in ion conduction are housed within the S5-6 regions. Moreover, the pattern of unitary conductance values obtained for chimeras in which a single P-loop or single S5-6 region was replaced suggest a concerted action of pore-lining regions in the control of ion conduction.
Aiyar,
The P-region and S6 of Kv3.1 contribute to the formation of the ion conduction pathway.
1994, Pubmed,
Xenbase
Aiyar,
The P-region and S6 of Kv3.1 contribute to the formation of the ion conduction pathway.
1994,
Pubmed
,
Xenbase
Almers,
Slow calcium and potassium currents across frog muscle membrane: measurements with a vaseline-gap technique.
1981,
Pubmed
Almers,
A non-selective cation conductance in frog muscle membrane blocked by micromolar external calcium ions.
1984,
Pubmed
Almers,
Non-selective conductance in calcium channels of frog muscle: calcium selectivity in a single-file pore.
1984,
Pubmed
Beam,
Function of a truncated dihydropyridine receptor as both voltage sensor and calcium channel.
1992,
Pubmed
Choe,
Permeation properties of inward-rectifier potassium channels and their molecular determinants.
2000,
Pubmed
,
Xenbase
Choi,
The internal quaternary ammonium receptor site of Shaker potassium channels.
1993,
Pubmed
,
Xenbase
Cibulsky,
The EEEE locus is the sole high-affinity Ca(2+) binding structure in the pore of a voltage-gated Ca(2+) channel: block by ca(2+) entering from the intracellular pore entrance.
2000,
Pubmed
,
Xenbase
De Jongh,
Characterization of the two size forms of the alpha 1 subunit of skeletal muscle L-type calcium channels.
1991,
Pubmed
Dirksen,
The S5-S6 linker of repeat I is a critical determinant of L-type Ca2+ channel conductance.
1997,
Pubmed
Doyle,
The structure of the potassium channel: molecular basis of K+ conduction and selectivity.
1998,
Pubmed
Ellinor,
Ca2+ channel selectivity at a single locus for high-affinity Ca2+ interactions.
1995,
Pubmed
,
Xenbase
Ertel,
Nomenclature of voltage-gated calcium channels.
2000,
Pubmed
Feng,
Amino acid residues outside of the pore region contribute to N-type calcium channel permeation.
2001,
Pubmed
Goulding,
Role of H5 domain in determining pore diameter and ion permeation through cyclic nucleotide-gated channels.
1993,
Pubmed
,
Xenbase
Hartmann,
Exchange of conduction pathways between two related K+ channels.
1991,
Pubmed
,
Xenbase
Hess,
Mechanism of ion permeation through calcium channels.
,
Pubmed
Hess,
Calcium channel selectivity for divalent and monovalent cations. Voltage and concentration dependence of single channel current in ventricular heart cells.
1986,
Pubmed
Hockerman,
Molecular determinants of high affinity phenylalkylamine block of L-type calcium channels in transmembrane segment IIIS6 and the pore region of the alpha1 subunit.
1997,
Pubmed
Hullin,
Calcium channel beta subunit heterogeneity: functional expression of cloned cDNA from heart, aorta and brain.
1992,
Pubmed
,
Xenbase
Immke,
Influence of non-P region domains on selectivity filter properties in voltage-gated K+ channels.
1998,
Pubmed
Isacoff,
Putative receptor for the cytoplasmic inactivation gate in the Shaker K+ channel.
1991,
Pubmed
,
Xenbase
Kim,
Studies on the structural requirements for the activity of the skeletal muscle dihydropyridine receptor/slow Ca2+ channel. Allosteric regulation of dihydropyridine binding in the absence of alpha 2 and beta components of the purified protein complex.
1990,
Pubmed
Koch,
Architecture of Ca(2+) channel pore-lining segments revealed by covalent modification of substituted cysteines.
2000,
Pubmed
,
Xenbase
Kuo,
A functional view of the entrances of L-type Ca2+ channels: estimates of the size and surface potential at the pore mouths.
1992,
Pubmed
Lansman,
Blockade of current through single calcium channels by Cd2+, Mg2+, and Ca2+. Voltage and concentration dependence of calcium entry into the pore.
1986,
Pubmed
Liman,
Subunit stoichiometry of a mammalian K+ channel determined by construction of multimeric cDNAs.
1992,
Pubmed
,
Xenbase
Liu,
Gated access to the pore of a voltage-dependent K+ channel.
1997,
Pubmed
Lopez,
Evidence that the S6 segment of the Shaker voltage-gated K+ channel comprises part of the pore.
1994,
Pubmed
,
Xenbase
MacKinnon,
Pore loops: an emerging theme in ion channel structure.
1995,
Pubmed
McCleskey,
The Ca channel in skeletal muscle is a large pore.
1985,
Pubmed
Meir,
Known calcium channel alpha1 subunits can form low threshold small conductance channels with similarities to native T-type channels.
1998,
Pubmed
Mikami,
Primary structure and functional expression of the cardiac dihydropyridine-sensitive calcium channel.
1989,
Pubmed
,
Xenbase
Morrill,
COOH-terminal truncated alpha(1S) subunits conduct current better than full-length dihydropyridine receptors.
2000,
Pubmed
,
Xenbase
Nakai,
Critical roles of the S3 segment and S3-S4 linker of repeat I in activation of L-type calcium channels.
1994,
Pubmed
Pragnell,
Cloning and tissue-specific expression of the brain calcium channel beta-subunit.
1991,
Pubmed
Ren,
Functional expression and characterization of skeletal muscle dihydropyridine receptors in Xenopus oocytes.
1997,
Pubmed
,
Xenbase
Repunte,
Extracellular links in Kir subunits control the unitary conductance of SUR/Kir6.0 ion channels.
1999,
Pubmed
Sather,
Distinctive biophysical and pharmacological properties of class A (BI) calcium channel alpha 1 subunits.
1993,
Pubmed
,
Xenbase
Seifert,
Molecular determinants of a Ca2+-binding site in the pore of cyclic nucleotide-gated channels: S5/S6 segments control affinity of intrapore glutamates.
1999,
Pubmed
,
Xenbase
Shieh,
Mutational analysis of ion conduction and drug binding sites in the inner mouth of voltage-gated K+ channels.
1994,
Pubmed
Slesinger,
The S4-S5 loop contributes to the ion-selective pore of potassium channels.
1993,
Pubmed
,
Xenbase
Striessnig,
Identification of a phenylalkylamine binding region within the alpha 1 subunit of skeletal muscle Ca2+ channels.
1990,
Pubmed
Taglialatela,
Comparison of H5, S6, and H5-S6 exchanges on pore properties of voltage-dependent K+ channels.
1994,
Pubmed
,
Xenbase
Tanabe,
Primary structure of the receptor for calcium channel blockers from skeletal muscle.
,
Pubmed
Tanabe,
Regions of the skeletal muscle dihydropyridine receptor critical for excitation-contraction coupling.
1990,
Pubmed
Tanabe,
Repeat I of the dihydropyridine receptor is critical in determining calcium channel activation kinetics.
1991,
Pubmed
Tang,
Molecular localization of ion selectivity sites within the pore of a human L-type cardiac calcium channel.
1993,
Pubmed
Williamson,
Nonglutamate pore residues in ion selection and conduction in voltage-gated Ca2+ channels.
1999,
Pubmed
Wu,
Side chain orientation in the selectivity filter of a voltage-gated Ca2+ channel.
2000,
Pubmed
,
Xenbase
Yang,
Molecular determinants of Ca2+ selectivity and ion permeation in L-type Ca2+ channels.
1993,
Pubmed
,
Xenbase
Yatani,
Alteration of channel characteristics by exchange of pore-forming regions between two structurally related Ca2+ channels.
1994,
Pubmed
Yellen,
Mutations affecting internal TEA blockade identify the probable pore-forming region of a K+ channel.
1991,
Pubmed
Yue,
Permeation in the dihydropyridine-sensitive calcium channel. Multi-ion occupancy but no anomalous mole-fraction effect between Ba2+ and Ca2+.
1990,
Pubmed
del Camino,
Blocker protection in the pore of a voltage-gated K+ channel and its structural implications.
2000,
Pubmed
