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.
Gating currents of inactivating and non-inactivating potassium channels expressed in Xenopus oocytes.
Stühmer W
,
Conti F
,
Stocker M
,
Pongs O
,
Heinemann SH
.
???displayArticle.abstract???
The Xenopus oocyte expression system in combination with patch-clamp techniques allows the measurement of ionic currents from a single class of genetically engineered ion channels. Ionic currents in the nanoampere range from oocytes injected with cRNA, corresponding to potassium channels, can be recorded in the inside-out patch configuration. These recordings have a high time resolution at low background noise. Substitution of impermeant ions for potassium and blocking of the channel conductance with tetraethylammonium allows the recording of potassium gating currents, Ig, which is hampered in natural excitable cells by the simultaneous presence of sodium channels and a variety of different potassium channels. The "on" transients, Ig(on), are fast and can have amplitudes of up to several tens of pA. Upon repolarization to -100 mV after small depolarizations, "off" gating currents, Ig(off)g, which reverse most of the "on" charge displacement, Q(on), within 1 ms, are readily observed. However, this fast recovery of the gating charge is drastically reduced upon increasing the amplitude of the depolarizing pulse. In contrast to sodium channels, this temporary charge immobilization is complete within a few milliseconds at positive membrane potentials. Furthermore, there seems to be no direct correlation between charge immobilization and inactivation because the same phenomenon occurs for channels that do not inactivate.
Almers,
Survival of K+ permeability and gating currents in squid axons perfused with K+-free media.
1980, Pubmed
Almers,
Survival of K+ permeability and gating currents in squid axons perfused with K+-free media.
1980,
Pubmed
Armstrong,
Inactivation of the sodium channel. II. Gating current experiments.
1977,
Pubmed
Armstrong,
Currents related to movement of the gating particles of the sodium channels.
1973,
Pubmed
Augustine,
Phosphorylation modulates potassium conductance and gating current of perfused giant axons of squid.
1990,
Pubmed
Baumann,
Structure of the voltage-dependent potassium channel is highly conserved from Drosophila to vertebrate central nervous systems.
1988,
Pubmed
Begenisich,
Conditioning hyperpolarization-induced delays in the potassium channels of myelinated nerve.
1979,
Pubmed
Bezanilla,
Gating currents associated with potassium channel activation.
1982,
Pubmed
Conti,
Quantal charge redistributions accompanying the structural transitions of sodium channels.
1989,
Pubmed
,
Xenbase
Conti,
Pressure dependence of sodium gating currents in the squid giant axon.
1984,
Pubmed
Gundersen,
Voltage-operated channels induced by foreign messenger RNA in Xenopus oocytes.
1983,
Pubmed
,
Xenbase
HODGKIN,
A quantitative description of membrane current and its application to conduction and excitation in nerve.
1952,
Pubmed
Keynes,
Kinetics and steady-state properties of the charged system controlling sodium conductance in the squid giant axon.
1974,
Pubmed
Kramer,
The gapped duplex DNA approach to oligonucleotide-directed mutation construction.
1984,
Pubmed
Lichtinghagen,
Molecular basis of altered excitability in Shaker mutants of Drosophila melanogaster.
1990,
Pubmed
,
Xenbase
Methfessel,
Patch clamp measurements on Xenopus laevis oocytes: currents through endogenous channels and implanted acetylcholine receptor and sodium channels.
1986,
Pubmed
,
Xenbase
Meves,
The effect of holding potential on the asymmetry currents in squid gaint axons.
1974,
Pubmed
Nonner,
Asymmetrical displacement currents in the membrane of frog myelinated nerve: early time course and effects of membrane potential.
1978,
Pubmed
Pongs,
Shaker encodes a family of putative potassium channel proteins in the nervous system of Drosophila.
1988,
Pubmed
Schauf,
Modifications of sodium channel gating in Myxicola giant axons by deuterium oxide, temperature, and internal cations.
1979,
Pubmed
Spires,
Pharmacological and kinetic analysis of K channel gating currents.
1989,
Pubmed
Stocker,
Alternative Shaker transcripts express either rapidly inactivating or noninactivating K+ channels.
1990,
Pubmed
,
Xenbase
Stühmer,
Patch clamp characterization of sodium channels expressed from rat brain cDNA.
1987,
Pubmed
,
Xenbase
Stühmer,
Structural parts involved in activation and inactivation of the sodium channel.
1989,
Pubmed
,
Xenbase
Stühmer,
Potassium channels expressed from rat brain cDNA have delayed rectifier properties.
1988,
Pubmed
,
Xenbase
White,
Activation of squid axon K+ channels. Ionic and gating current studies.
1985,
Pubmed
Zagotta,
Voltage-dependent gating of Shaker A-type potassium channels in Drosophila muscle.
1990,
Pubmed
