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.
Characterization of stretch-activated ion channels in Xenopus oocytes.
Yang XC
,
Sachs F
.
???displayArticle.abstract???
1. The gating and permeation properties of endogenous stretch-activated (SA) ion channels in Xenopus oocytes have been studied using the patch-clamp single channel recording technique. 2. As estimated from the probability of being open (Po), SA channels were equally sensitive to suction or pressure. The Po was also weakly sensitive to voltage, increasing with depolarization. Channel activation did not require Ca2+. 3. Kinetic analysis of single-channel records indicated that there are three closed states and one open state. Among three closed-time distributions, the longest was the most sensitive to both pipette pressure and membrane voltage. The open time was independent of both pressure and voltage under a wide variety of ionic conditions, but was sensitive to the species of extracellular ion as follows: Na+ greater than Cs+ greater than K+ greater than Rb+ greater than Li+. The open time had a monotonic mole fraction relationship in mixtures of Li+ and K+. 4. The SA channels were cation-selective inward rectifiers. The selectivity for permeation, based on slope conductance, was: K+ greater than NH4+ greater than Cs+ greater than Rb+ greater than Na+ greater than Li+ greater than Ca2+. 5. Tetraethylammonium (TEA+) was impermeable but was not a channel blocker. 6.Open-channel current amplitude saturated with increasing extracellular K+, and was a monotonic function of the mole fraction of Li+ and K+ in mixtures of the two ions. 7. The channel has at least two separate ion binding sites: an intra-channel site suggested by the permeation data, and an allosteric site suggested by the voltage-independent effects of permeant ions on open time. A symmetric two-barrier, one-site model can quantitatively describe the permeation data. A kinetic model is proposed to quantify the gating kinetics and the effect of ion binding at the allosteric site.
Bezanilla,
Negative conductance caused by entry of sodium and cesium ions into the potassium channels of squid axons.
1972, Pubmed
Bezanilla,
Negative conductance caused by entry of sodium and cesium ions into the potassium channels of squid axons.
1972,
Pubmed
Cavalié,
Elementary currents through Ca2+ channels in guinea pig myocytes.
1983,
Pubmed
Colquhoun,
On the stochastic properties of single ion channels.
1981,
Pubmed
Cooper,
A cation channel in frog lens epithelia responsive to pressure and calcium.
1986,
Pubmed
,
Xenbase
FATT,
The ionic requirements for the production of action potentials in crustacean muscle fibres.
1958,
Pubmed
Gage,
Effects of permeant monovalent cations on end-plate channels.
1979,
Pubmed
Guharay,
Stretch-activated single ion channel currents in tissue-cultured embryonic chick skeletal muscle.
1984,
Pubmed
Guharay,
Mechanotransducer ion channels in chick skeletal muscle: the effects of extracellular pH.
1985,
Pubmed
Gustin,
A mechanosensitive ion channel in the yeast plasma membrane.
1988,
Pubmed
Hamill,
Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
1981,
Pubmed
HODGKIN,
The components of membrane conductance in the giant axon of Loligo.
1952,
Pubmed
Kirber,
Stretch-activated ion channels in smooth muscle: a mechanism for the initiation of stretch-induced contraction.
1988,
Pubmed
Marchais,
Interaction of permeant ions with channels activated by acetylcholine in Aplysia neurones.
1979,
Pubmed
Methfessel,
Patch clamp measurements on Xenopus laevis oocytes: currents through endogenous channels and implanted acetylcholine receptor and sodium channels.
1986,
Pubmed
,
Xenbase
MONOD,
ON THE NATURE OF ALLOSTERIC TRANSITIONS: A PLAUSIBLE MODEL.
1965,
Pubmed
Moody,
A nonselective cation channel activated by membrane deformation in oocytes of the ascidian Boltenia villosa.
1989,
Pubmed
Morris,
Mechanosensitive ion channels.
1990,
Pubmed
Neher,
The charge carried by single-channel currents of rat cultured muscle cells in the presence of local anaesthetics.
1983,
Pubmed
Nelson,
Effects of permeant ions and blockers on properties of single calcium channels from brains.
1987,
Pubmed
Pietrobon,
Conformational changes associated with ion permeation in L-type calcium channels.
1988,
Pubmed
Sachs,
The automated analysis of data from single ionic channels.
1982,
Pubmed
Sachs,
Single-channel electrophysiology: use of the patch clamp.
1983,
Pubmed
Sachs,
Mechanical transduction in biological systems.
1988,
Pubmed
Sakmann,
Role of acetylcholine receptor subunits in gating of the channel.
,
Pubmed
,
Xenbase
Sivasubramanian,
Mutational analysis of the signal-anchor domain of influenza virus neuraminidase.
1987,
Pubmed
Stinnakre,
Cyclic adenosine monophosphate, calcium, acetylcholine and the current induced by adenosine in the Xenopus oocyte.
1986,
Pubmed
,
Xenbase
Xiang,
LPROC: a software tool for analysing single-channel data.
1988,
Pubmed
Yang,
Block of stretch-activated ion channels in Xenopus oocytes by gadolinium and calcium ions.
1989,
Pubmed
,
Xenbase
