Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Biophys J
2002 Jun 01;826:3022-36. doi: 10.1016/S0006-3495(02)75643-9.
Show Gene links
Show Anatomy links
Inactivation and pharmacological properties of sqKv1A homotetramers in Xenopus oocytes cannot account for behavior of the squid "delayed rectifier" K(+) conductance.
Jerng HH
,
Gilly WF
.
???displayArticle.abstract???
Considerable published evidence suggests that alpha-subunits of the cloned channel sqKv1A compose the "delayed rectifier" in the squid giant axon system, but discrepancies regarding inactivation properties of cloned versus native channels exist. In this paper we define the mechanism of inactivation for sqKv1A channels in Xenopus oocytes to investigate these and other discrepancies. Inactivation of sqKv1A in Xenopus oocytes was found to be unaffected by genetic truncation of the N-terminus, but highly sensitive to certain amino acid substitutions around the external mouth of the pore. External TEA and K(+) ions slowed inactivation of sqKv1A channels in oocytes, and chloramine T (Chl-T) accelerated inactivation. These features are all consistent with a C-type inactivation mechanism as defined for Shaker B channels. Treatment of native channels in giant fiber lobe neurons with TEA or high K(+) does not slow inactivation, nor does Chl-T accelerate it. Pharmacological differences between the two channel types were also found for 4-aminopyridine (4AP). SqKv1A's affinity for 4AP was poor at rest and increased after activation, whereas 4AP block occurred much more readily at rest with native channels than when they were activated. These results suggest that important structural differences between sqKv1A homotetramers and native squid channels are likely to exist around the external and internal mouths of the pore.
Armstrong,
A model for 4-aminopyridine action on K channels: similarities to tetraethylammonium ion action.
2001, Pubmed
Armstrong,
A model for 4-aminopyridine action on K channels: similarities to tetraethylammonium ion action.
2001,
Pubmed
Armstrong,
Inactivation of the potassium conductance and related phenomena caused by quaternary ammonium ion injection in squid axons.
1969,
Pubmed
Armstrong,
Currents related to movement of the gating particles of the sodium channels.
1973,
Pubmed
Baukrowitz,
Modulation of K+ current by frequency and external [K+]: a tale of two inactivation mechanisms.
1995,
Pubmed
Baukrowitz,
Use-dependent blockers and exit rate of the last ion from the multi-ion pore of a K+ channel.
1996,
Pubmed
Brock,
Temperature-dependent expression of a squid Kv1 channel in Sf9 cells and functional comparison with the native delayed rectifier.
2001,
Pubmed
Campbell,
The calcium-independent transient outward potassium current in isolated ferret right ventricular myocytes. II. Closed state reverse use-dependent block by 4-aminopyridine.
1993,
Pubmed
Choi,
Tetraethylammonium blockade distinguishes two inactivation mechanisms in voltage-activated K+ channels.
1991,
Pubmed
Choquet,
Mechanism of 4-aminopyridine action on voltage-gated potassium channels in lymphocytes.
1992,
Pubmed
Covarrubias,
Shaker, Shal, Shab, and Shaw express independent K+ current systems.
1991,
Pubmed
,
Xenbase
Doyle,
The structure of the potassium channel: molecular basis of K+ conduction and selectivity.
1998,
Pubmed
Ellis,
Interaction of a toxin from the scorpion Tityus serrulatus with a cloned K+ channel from squid (sqKv1A).
2001,
Pubmed
,
Xenbase
Gandhi,
Reconstructing voltage sensor-pore interaction from a fluorescence scan of a voltage-gated K+ channel.
2000,
Pubmed
Gilly,
Control of the spatial distribution of sodium channels in giant fiber lobe neurons of the squid.
1990,
Pubmed
Grissmer,
TEA prevents inactivation while blocking open K+ channels in human T lymphocytes.
1989,
Pubmed
HODGKIN,
A quantitative description of membrane current and its application to conduction and excitation in nerve.
1952,
Pubmed
Harris,
A permanent ion binding site located between two gates of the Shaker K+ channel.
1998,
Pubmed
,
Xenbase
Hoshi,
Biophysical and molecular mechanisms of Shaker potassium channel inactivation.
1990,
Pubmed
,
Xenbase
Isacoff,
Evidence for the formation of heteromultimeric potassium channels in Xenopus oocytes.
1990,
Pubmed
,
Xenbase
Iverson,
The role of the divergent amino and carboxyl domains on the inactivation properties of potassium channels derived from the Shaker gene of Drosophila.
1990,
Pubmed
,
Xenbase
Jerng,
K+ channel inactivation mediated by the concerted action of the cytoplasmic N- and C-terminal domains.
1997,
Pubmed
,
Xenbase
Jerng,
Inactivation gating of Kv4 potassium channels: molecular interactions involving the inner vestibule of the pore.
1999,
Pubmed
,
Xenbase
Kirsch,
Segmental exchanges define 4-aminopyridine binding and the inner mouth of K+ pores.
1993,
Pubmed
Kirsch,
Site of action and active form of aminopyridines in squid axon membranes.
1983,
Pubmed
Kirsch,
Modulation of aminopyridine block of potassium currents in squid axon.
1986,
Pubmed
Kirsch,
Gating-dependent mechanism of 4-aminopyridine block in two related potassium channels.
1993,
Pubmed
,
Xenbase
Larsson,
A conserved glutamate is important for slow inactivation in K+ channels.
2000,
Pubmed
,
Xenbase
Li,
Specification of subunit assembly by the hydrophilic amino-terminal domain of the Shaker potassium channel.
1992,
Pubmed
Liu,
Gated access to the pore of a voltage-dependent K+ channel.
1997,
Pubmed
Liu,
Natural substitutions at highly conserved T1-domain residues perturb processing and functional expression of squid Kv1 channels.
2001,
Pubmed
,
Xenbase
Llano,
Ionic conductances of squid giant fiber lobe neurons.
1986,
Pubmed
Llano,
Potassium conductance of the squid giant axon. Single-channel studies.
1988,
Pubmed
López-Barneo,
Effects of external cations and mutations in the pore region on C-type inactivation of Shaker potassium channels.
1993,
Pubmed
,
Xenbase
MacKinnon,
Functional stoichiometry of Shaker potassium channel inactivation.
1993,
Pubmed
,
Xenbase
MacKinnon,
Determination of the subunit stoichiometry of a voltage-activated potassium channel.
1991,
Pubmed
,
Xenbase
Mathes,
Fast inactivation of delayed rectifier K conductance in squid giant axon and its cell bodies.
1997,
Pubmed
McCormack,
A characterization of the activating structural rearrangements in voltage-dependent Shaker K+ channels.
1994,
Pubmed
McFarlane,
Spatial localization of calcium channels in giant fiber lobe neurons of the squid (Loligo opalescens).
1996,
Pubmed
Molina,
Pore mutations in Shaker K+ channels distinguish between the sites of tetraethylammonium blockade and C-type inactivation.
1997,
Pubmed
Nealey,
Potassium channels in squid neuron cell bodies: comparison to axonal channels.
1993,
Pubmed
Perez-Cornejo,
Proton probing of the charybdotoxin binding site of Shaker K+ channels.
1998,
Pubmed
,
Xenbase
Perozo,
Single channel studies of the phosphorylation of K+ channels in the squid giant axon. II. Nonstationary conditions.
1991,
Pubmed
Pérez-Cornejo,
H+ ion modulation of C-type inactivation of Shaker K+ channels.
1999,
Pubmed
Rosenthal,
Molecular identification of SqKv1A. A candidate for the delayed rectifier K channel in squid giant axon.
1996,
Pubmed
,
Xenbase
Rosenthal,
A family of delayed rectifier Kv1 cDNAs showing cell type-specific expression in the squid stellate ganglion/giant fiber lobe complex.
1997,
Pubmed
Ruppersberg,
Heteromultimeric channels formed by rat brain potassium-channel proteins.
1990,
Pubmed
,
Xenbase
Russell,
Block by 4-aminopyridine of a Kv1.2 delayed rectifier K+ current expressed in Xenopus oocytes.
1994,
Pubmed
,
Xenbase
Schlief,
Modification of C-type inactivating Shaker potassium channels by chloramine-T.
1996,
Pubmed
,
Xenbase
Stephens,
On the mechanism of 4-aminopyridine action on the cloned mouse brain potassium channel mKv1.1.
1994,
Pubmed
Thompson,
Electrostatic interaction between charybdotoxin and a tetrameric mutant of Shaker K(+) channels.
2000,
Pubmed
,
Xenbase
Tseng,
Reverse use dependence of Kv4.2 blockade by 4-aminopyridine.
1996,
Pubmed
,
Xenbase
Xu,
Assembly of voltage-gated potassium channels. Conserved hydrophilic motifs determine subfamily-specific interactions between the alpha-subunits.
1995,
Pubmed
Yamane,
4-Aminopyridine block of the noninactivating cloned K+ channel Kv1.5 expressed in Xenopus oocytes.
1995,
Pubmed
,
Xenbase
Yao,
Modulation of 4-AP block of a mammalian A-type K channel clone by channel gating and membrane voltage.
1994,
Pubmed
,
Xenbase
Yeh,
Dynamics of aminopyridine block of potassium channels in squid axon membrane.
1976,
Pubmed
Yellen,
The moving parts of voltage-gated ion channels.
1998,
Pubmed
