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Stretch-activation and stretch-inactivation of Shaker-IR, a voltage-gated K+ channel.
Gu CX, Juranka PF, Morris CE.
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Mechanosensitive (MS) ion channels are ubiquitous in eukaryotic cell types but baffling because of their contentious physiologies and diverse molecular identities. In some cellular contexts mechanically responsive ion channels are undoubtedly mechanosensory transducers, but it does not follow that all MS channels are mechanotransducers. Here we demonstrate, for an archetypical voltage-gated channel (Shaker-IR; inactivation-removed), robust MS channel behavior. In oocyte patches subjected to stretch, Shaker-IR exhibits both stretch-activation (SA) and stretch-inactivation (SI). SA is seen when prestretch P(open) (set by voltage) is low, and SI is seen when it is high. The stretch effects occur in cell-attached and excised patches at both macroscopic and single-channel levels. Were one ignorant of this particular MS channel's identity, one might propose it had been designed as a sophisticated reporter of bilayer tension. Knowing Shaker-IR's provenance and biology, however, such a suggestion would be absurd. We argue that the MS responses of Shaker-IR reflect not overlooked "mechano-gating" specializations of Shaker, but a common property of multiconformation membrane proteins: inherent susceptibility to bilayer tension. The molecular diversity of MS channels indicates that susceptibility to bilayer tension is hard to design out of dynamic membrane proteins. Presumably the cost of being insusceptible to bilayer tension often outweighs the benefits, especially where the in situ milieu of channels can provide mechanoprotection.
Bezanilla,
The voltage sensor in voltage-dependent ion channels.
2000, Pubmed
Bezanilla,
The voltage sensor in voltage-dependent ion channels.
2000,
Pubmed Conti,
Pressure dependence of sodium gating currents in the squid giant axon.
1984,
Pubmed Elinder,
Effects of gadolinium on ion channels in the myelinated axon of Xenopus laevis: four sites of action.
1994,
Pubmed
,
Xenbase Franco-Obregón,
Mechanosensitive ion channels in skeletal muscle from normal and dystrophic mice.
1994,
Pubmed García-Añoveros,
The nematode degenerin UNC-105 forms ion channels that are activated by degeneration- or hypercontraction-causing mutations.
1998,
Pubmed
,
Xenbase Guharay,
Stretch-activated single ion channel currents in tissue-cultured embryonic chick skeletal muscle.
1984,
Pubmed Gustin,
A mechanosensitive ion channel in the yeast plasma membrane.
1988,
Pubmed Hamill,
Induced membrane hypo/hyper-mechanosensitivity: a limitation of patch-clamp recording.
1997,
Pubmed Hoshi,
Shaker potassium channel gating. I: Transitions near the open state.
1994,
Pubmed
,
Xenbase Hoshi,
Two types of inactivation in Shaker K+ channels: effects of alterations in the carboxy-terminal region.
1991,
Pubmed
,
Xenbase Hudspeth,
How hearing happens.
1997,
Pubmed Ismailov,
Mechanosensitivity of an epithelial Na+ channel in planar lipid bilayers: release from Ca2+ block.
1997,
Pubmed Ji,
Mechanosensitivity of the cardiac muscarinic potassium channel. A novel property conferred by Kir3.4 subunit.
1998,
Pubmed
,
Xenbase Langton,
Calcium channel currents recorded from isolated myocytes of rat basilar artery are stretch sensitive.
1993,
Pubmed Lee,
Membrane stretch increases the activity of Ca(2+)-activated K+ channels in rabbit coronary vascular smooth muscles.
2000,
Pubmed Loots,
Molecular coupling of S4 to a K(+) channel's slow inactivation gate.
2000,
Pubmed Martens,
Differential targeting of Shaker-like potassium channels to lipid rafts.
2000,
Pubmed Meyer,
Temperature and pressure dependence of Shaker K+ channel N- and C-type inactivation.
1997,
Pubmed
,
Xenbase Morris,
Are stretch-sensitive channels in molluscan cells and elsewhere physiological mechanotransducers?
1992,
Pubmed
,
Xenbase Morris,
Stretch-inactivated ion channels coexist with stretch-activated ion channels.
1989,
Pubmed Morris,
Failure to elicit neuronal macroscopic mechanosensitive currents anticipated by single-channel studies.
1991,
Pubmed Morris,
Cell surface area regulation and membrane tension.
2001,
Pubmed Paoletti,
Mechanosensitivity of NMDA receptors in cultured mouse central neurons.
1994,
Pubmed Patel,
A mammalian two pore domain mechano-gated S-like K+ channel.
1998,
Pubmed Perozo,
Three-dimensional architecture and gating mechanism of a K+ channel studied by EPR spectroscopy.
1998,
Pubmed Pleumsamran,
Membrane stretch augments the cardiac muscarinic K+ channel activity.
1995,
Pubmed Sachs,
Mechanosensitive ion channels in nonspecialized cells.
1998,
Pubmed Sachs,
Does a stretch-inactivated cation channel integrate osmotic and peptidergic signals?
2000,
Pubmed Small,
Pharmacology of stretch-activated K channels in Lymnaea neurones.
1995,
Pubmed Small,
Delayed activation of single mechanosensitive channels in Lymnaea neurons.
1994,
Pubmed
,
Xenbase Sukharev,
The gating mechanism of the large mechanosensitive channel MscL.
2001,
Pubmed Tabarean,
Membrane stretch affects gating modes of a skeletal muscle sodium channel.
1999,
Pubmed
,
Xenbase Terakawa,
Are axoplasmic microtubules necessary for membrane excitation?
1985,
Pubmed Tytgat,
Effect of lanthanum on voltage-dependent gating of a cloned mammalian neuronal potassium channel.
1997,
Pubmed
,
Xenbase Vandorpe,
FMRFamide and membrane stretch as activators of the Aplysia S-channel.
1994,
Pubmed Wan,
Activation of mechanosensitive currents in traumatized membrane.
1999,
Pubmed Wilkinson,
Effects of mechano-gated cation channel blockers on Xenopus oocyte growth and development.
1998,
Pubmed
,
Xenbase Yang,
Block of stretch-activated ion channels in Xenopus oocytes by gadolinium and calcium ions.
1989,
Pubmed
,
Xenbase Yao,
Auxiliary Hyperkinetic beta subunit of K+ channels: regulation of firing properties and K+ currents in Drosophila neurons.
1999,
Pubmed Zaccai,
How soft is a protein? A protein dynamics force constant measured by neutron scattering.
2000,
Pubmed Zhang,
On the discrepancy between whole-cell and membrane patch mechanosensitivity in Xenopus oocytes.
2000,
Pubmed
,
Xenbase
