Mechanisms of the inhibition of Shaker potassium channels by protons

2003 ◽  
Vol 447 (1) ◽  
pp. 44-54 ◽  
Author(s):  
John G. Starkus ◽  
Zoltan Varga ◽  
Roland Sch�nherr ◽  
Stefan H. Heinemann
Keyword(s):  
Potassium Channels ◽  
Shaker Potassium Channels

scholarly journals Probing the Cavity of the Slow Inactivated Conformation of Shaker Potassium Channels

2007 ◽  
Vol 129 (5) ◽  
pp. 403-418 ◽  
Author(s):  
Gyorgy Panyi ◽  
Carol Deutsch
Keyword(s):  
Potassium Channels ◽  
Binding Site ◽  
Conformational Change ◽  
Marked Decrease ◽  
Selectivity Filter ◽  
Slow Inactivation ◽  
Voltage Gated ◽  
Activation Gate ◽  
Shaker Potassium Channels

Slow inactivation involves a local rearrangement of the outer mouth of voltage-gated potassium channels, but nothing is known regarding rearrangements in the cavity between the activation gate and the selectivity filter. We now report that the cavity undergoes a conformational change in the slow-inactivated state. This change is manifest as altered accessibility of residues facing the aqueous cavity and as a marked decrease in the affinity of tetraethylammonium for its internal binding site. These findings have implications for global alterations of the channel during slow inactivation and putative coupling between activation and slow-inactivation gates.

scholarly journals Key Residues in the Interface between Voltage Sensor and Pore Domain in Shaker Potassium Channels

2018 ◽  
Vol 114 (3) ◽  
pp. 476a
Author(s):  
João L. Carvalho-de-Souza ◽  
Francisco Bezanilla
Keyword(s):  
Potassium Channels ◽  
Voltage Sensor ◽  
Key Residues ◽  
Pore Domain ◽  
Shaker Potassium Channels

scholarly journals Cross Talk between Activation and Slow Inactivation Gates of Shaker Potassium Channels

2006 ◽  
Vol 128 (5) ◽  
pp. 547-559 ◽  
Author(s):  
Gyorgy Panyi ◽  
Carol Deutsch
Keyword(s):  
Potassium Channels ◽  
Cross Talk ◽  
Cysteine Residue ◽  
Slow Inactivation ◽  
Fundamental Factor ◽  
Functional Assays ◽  
Activation Gate ◽  
The Status ◽  
Shaker Potassium Channels ◽  
Rate Of Activation

This study addresses the energetic coupling between the activation and slow inactivation gates of Shaker potassium channels. To track the status of the activation gate in inactivated channels that are nonconducting, we used two functional assays: the accessibility of a cysteine residue engineered into the protein lining the pore cavity (V474C) and the liberation by depolarization of a Cs+ ion trapped behind the closed activation gate. We determined that the rate of activation gate movement depends on the state of the inactivation gate. A closed inactivation gate favors faster opening and slower closing of the activation gate. We also show that hyperpolarization closes the activation gate long before a channel recovers from inactivation. Because activation and slow inactivation are ubiquitous gating processes in potassium channels, the cross talk between them is likely to be a fundamental factor in controlling ion flux across membranes.

scholarly journals External barium influences the gating charge movement of Shaker potassium channels

1997 ◽  
Vol 72 (1) ◽  
pp. 77-84 ◽  
Author(s):  
R.S. Hurst ◽  
M.J. Roux ◽  
L. Toro ◽  
E. Stefani
Keyword(s):  
Potassium Channels ◽  
Charge Movement ◽  
Gating Charge ◽  
Shaker Potassium Channels

scholarly journals Generalized Interaction Energy Analysis of Intersubunit Linkage in Shaker Potassium Channels

2014 ◽  
Vol 106 (2) ◽  
pp. 742a
Author(s):  
Sandipan Chowdhury ◽  
Benjamin M. Haehnel ◽  
Baron Chanda
Keyword(s):  
Potassium Channels ◽  
Interaction Energy ◽  
Energy Analysis ◽  
Shaker Potassium Channels

scholarly journals Function of Shaker Potassium Channels Produced by Cell-Free Translation Upon Injection into Xenopus Oocytes

2013 ◽  
Vol 104 (2) ◽  
pp. 197a
Author(s):  
Brian W. Jarecki ◽  
Shin-ichi Makino ◽  
Emily T. Beebe ◽  
Brian G. Fox ◽  
Baron Chanda
Keyword(s):  
Potassium Channels ◽  
Xenopus Oocytes ◽  
Free Translation ◽  
Shaker Potassium Channels

Modification of C-type inactivating Shaker potassium channels by chloramine-T

1996 ◽  
Vol 431 (4) ◽  
pp. 483-493 ◽  
Author(s):  
Thomas Schlief ◽  
Roland Schönherr ◽  
S. H. Heinemann
Keyword(s):  
Potassium Channels ◽  
Chloramine T ◽  
Shaker Potassium Channels

Use of voltage clamp fluorimetry in understanding potassium channel gating: a review of Shaker fluorescence data

2009 ◽  
Vol 87 (6) ◽  
pp. 411-418 ◽  
Author(s):  
A.J. Horne ◽  
D. Fedida
Keyword(s):  
Potassium Channels ◽  
Potassium Channel ◽  
Voltage Clamp ◽  
Channel Gating ◽  
Specific Protein ◽  
Channel Activation ◽  
Shaker Potassium Channel ◽  
Inactivation Gating ◽  
Nanosecond Time Resolution ◽  
Shaker Potassium Channels

Voltage clamp fluorimetry (VCF) utilizes fluorescent probes that covalently bind to cysteine residues introduced into proteins and emit light as a function of their environment. Measurement of this emitted light during membrane depolarization reveals changes in the emission level as the environment of the labelled residue changes. This allows for the correlation of channel gating events with movement of specific protein moieties, at nanosecond time resolution. Since the pioneering use of this technique to investigate Shaker potassium channel activation movements, VCF has become an invaluable technique used to understand ion channel gating. This review summarizes the theory and some of the data on the application of the VCF technique. Although its usage has expanded beyond voltage-gated potassium channels and VCF is now used in a number of other voltage- and ligand-gated channels, we will focus on studies conducted in Shaker potassium channels, and what they have told us about channel activation and inactivation gating.

Sign in / Sign up

Export Citation Format

Share Document