Spectroscopic mapping of voltage sensor movement in the Shaker potassium channel

@article{Glauner1999SpectroscopicMO,
  title={Spectroscopic mapping of voltage sensor movement in the Shaker potassium channel},
  author={Kathi S Glauner and Lidia M. Mannuzzu and Chris S. Gandhi and Ehud Y Isacoff},
  journal={Nature},
  year={1999},
  volume={402},
  pages={813-817}
}
Voltage-gated ion channels underlie the generation of action potentials and trigger neurosecretion and muscle contraction. These channels consist of an inner pore-forming domain, which contains the ion permeation pathway and elements of its gates, together with four voltage-sensing domains, which regulate the gates. To understand the mechanism of voltage sensing it is necessary to define the structure and motion of the S4 segment, the portion of each voltage-sensing domain that moves charged… Expand
Constraints on Voltage Sensor Movement in the Shaker K+ Channel
TLDR
This work used two methods to test for analogous motions in the Shaker K+ channel, and found that residues predicted to lie near the top of S3 did not exhibit any change in aqueous exposure during the gating cycle, arguing against large-scale movements of Shaker's S3–S4 voltage-sensor paddle. Expand
Atomic scale movement of the voltage-sensing region in a potassium channel measured via spectroscopy
TLDR
Measured distance changes suggest that the region associated with the S4 segment undergoes a rotation and possible tilt, rather than a large transmembrane movement, in response to voltage, the first in situ measurement of atomic scale movement in a trans Membrane protein. Expand
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The emerging structural model for voltage sensor function opens the way to development of a new generation of ion-channel drugs that act on voltage sensors rather than blocking the pore. Expand
Gating charge displacement in voltage-gated ion channels involves limited transmembrane movement
TLDR
A molecular model of voltage gating is proposed that can account for the observed 13e gating charge with limited transmembrane S4 movement and indicates that the S4 segment does not translocate across the lipid bilayer. Expand
Small vertical movement of a K+ channel voltage sensor measured with luminescence energy transfer
TLDR
This small movement of the voltage-sensor segments in functional Shaker K+ channels supports an alternative model in which the protein shapes the electric field profile, focusing it across a narrow region of S4 (ref. 6). Expand
The Cooperative Voltage Sensor Motion that Gates a Potassium Channel
TLDR
Using fluorescence to monitor structural rearrangements in a Shaker channel mutant, the ILT channel, it is found that opening is accompanied by a previously unknown and cooperative movement of S4 that appears to be coupled to the internal S6 gate and to two forms of slow inactivation. Expand
Structural basis for gating charge movement in the voltage sensor of a sodium channel
TLDR
High-resolution structural models of resting, intermediate, and activated states of the voltage-sensing domain of the bacterial sodium channel NaChBac are constructed using the Rosetta modeling method, crystal structures of related channels, and experimental data showing state-dependent interactions between the gating charge-carrying arginines in the S4 segment and negatively charged residues in neighboring transmembrane segments. Expand
Voltage Sensor of Kv1.2: Structural Basis of Electromechanical Coupling
TLDR
The x-ray crystal structure of a mammalian Shaker family potassium ion (K+) channel grew three-dimensional crystals, with an internal arrangement that left the voltage sensors in an apparently native conformation, allowing the investigation of the mechanism by which these channels sense cell membrane voltage. Expand
Structural mechanism of voltage-dependent gating in an isolated voltage-sensing domain
TLDR
Crystal structures of the Ciona intestinalis VSD (Ci-VSD) are determined in putatively active and resting conformations and provide an explicit mechanism for voltage sensing and set the basis for electromechanical coupling in voltage-dependent enzymes and ion channels. Expand
The twisted ion-permeation pathway of a resting voltage-sensing domain
TLDR
A structure-guided perturbation analysis of the omega conductance of the Shaker potassium channel is performed to map its VSD permeation pathway, finding that there are four omega pores per channel, which is consistent with one conduction path per VSD. Expand
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