scholarly journals The Lipid Activation Mechanism of a Transmembrane Potassium Channel

2020 ◽  
Vol 142 (33) ◽  
pp. 14102-14116
Author(s):  
Collin G. Borcik ◽  
Derek B. Versteeg ◽  
Reza Amani ◽  
Maryam Yekefallah ◽  
Nazmul H. Khan ◽  
...  
Keyword(s):  
Potassium Channel ◽  
Activation Mechanism ◽  
Lipid Activation

scholarly journals Voltage-dependent gating and gating charge measurements in the Kv1.2 potassium channel

2015 ◽  
Vol 145 (4) ◽  
pp. 345-358 ◽  
Author(s):  
Itzel G. Ishida ◽  
Gisela E. Rangel-Yescas ◽  
Julia Carrasco-Zanini ◽  
León D. Islas
Keyword(s):  
Ion Channels ◽  
Potassium Channel ◽  
Structural Data ◽  
Activation Mechanism ◽  
Voltage Sensitivity ◽  
Structural Interpretation ◽  
Kv Channel ◽  
Gating Charge ◽  
Voltage Dependent ◽  
Electrophysiological Findings

Much has been learned about the voltage sensors of ion channels since the x-ray structure of the mammalian voltage-gated potassium channel Kv1.2 was published in 2005. High resolution structural data of a Kv channel enabled the structural interpretation of numerous electrophysiological findings collected in various ion channels, most notably Shaker, and permitted the development of meticulous computational simulations of the activation mechanism. The fundamental premise for the structural interpretation of functional measurements from Shaker is that this channel and Kv1.2 have the same characteristics, such that correlation of data from both channels would be a trivial task. We tested these assumptions by measuring Kv1.2 voltage-dependent gating and charge per channel. We found that the Kv1.2 gating charge is near 10 elementary charges (eo), ∼25% less than the well-established 13–14 eo in Shaker. Next, we neutralized positive residues in the Kv1.2 S4 transmembrane segment to investigate the cause of the reduction of the gating charge and found that, whereas replacing R1 with glutamine decreased voltage sensitivity to ∼50% of the wild-type channel value, mutation of the subsequent arginines had a much smaller effect. These data are in marked contrast to the effects of charge neutralization in Shaker, where removal of the first four basic residues reduces the gating charge by roughly the same amount. In light of these differences, we propose that the voltage-sensing domains (VSDs) of Kv1.2 and Shaker might undergo the same physical movement, but the septum that separates the aqueous crevices in the VSD of Kv1.2 might be thicker than Shaker’s, accounting for the smaller Kv1.2 gating charge.

Characterization of Mammalian Potassium Channel Genes

1991 ◽  
Author(s):  
James O. Douglass ◽  
◽  
Macdonald Christie ◽  
John P. Adelman ◽  
R. Alan North
Keyword(s):  
Potassium Channel

Successful therapy with glibenclamid in a patient with a muation of KIR 6.2 subunit of the ATP-sensitive potassium channel

2006 ◽  
Vol 37 (03) ◽  
Author(s):  
F Hörster ◽  
AT Hattersley ◽  
FM Ashcroft ◽  
J Grulich-Henn ◽  
T Bast ◽  
...  
Keyword(s):  
Potassium Channel ◽  
Successful Therapy

Limbic encephalitis with voltage gated potassium channel antibodies in a child

2008 ◽  
Vol 39 (01) ◽  
Author(s):  
E Haberlandt ◽  
CG Bien ◽  
A Reiter ◽  
B Simma ◽  
R Crazzolara ◽  
...  
Keyword(s):  
Potassium Channel ◽  
Limbic Encephalitis ◽  
Voltage Gated
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