Molecular Determinants of Inactivation and Dofetilide Block inether a-go-go (EAG) Channels and EAG-Related K+ Channels

2001 ◽  
Vol 60 (6) ◽  
pp. 1343-1348 ◽  
Author(s):  
Eckhard Ficker ◽  
Wolfgang Jarolimek ◽  
Arthur M. Brown
Keyword(s):  
K Channels ◽  
Molecular Determinants ◽  
Eag Channels

scholarly journals Molecular Determinants of the Slow Off-Gating Component in Shaker K+ Channels

2010 ◽  
Vol 98 (3) ◽  
pp. 522a
Author(s):  
Zarah Batulan ◽  
Georges A. Haddad ◽  
Rikard Blunck
Keyword(s):  
K Channels ◽  
Molecular Determinants

scholarly journals Molecular Determinants for Assembly of G-protein-activated Inwardly Rectifying K+Channels

1997 ◽  
Vol 272 (16) ◽  
pp. 10823-10830 ◽  
Author(s):  
Robert Woodward ◽  
Edward B. Stevens ◽  
Ruth D. Murrell-Lagnado
Keyword(s):  
G Protein ◽  
K Channels ◽  
Molecular Determinants ◽  
Inwardly Rectifying

scholarly journals Molecular Determinants of Dofetilide Block of HERG K + Channels

1998 ◽  
Vol 82 (3) ◽  
pp. 386-395 ◽  
Author(s):  
Eckhard Ficker ◽  
Wolfgang Jarolimek ◽  
Johann Kiehn ◽  
Arnd Baumann ◽  
Arthur M. Brown
Keyword(s):  
K Channels ◽  
Molecular Determinants

Molecular determinants of ion conduction and inactivation in K+ channels

1995 ◽  
Vol 268 (3) ◽  
pp. C535-C556 ◽  
Author(s):  
M. Kukuljan ◽  
P. Labarca ◽  
R. Latorre
Keyword(s):  
K Channel ◽  
Amino Acid Residues ◽  
Fast Inactivation ◽  
Transmembrane Segment ◽  
Ion Conduction ◽  
K Channels ◽  
Type K ◽  
Molecular Determinants ◽  
Inward Rectifiers ◽  
Membrane Spanning

K+ channel-forming proteins can be grouped into three families that differ by the number of potential membrane-spanning segments. The largest of these families is composed of tetrameric channels with subunits containing six putative membrane-spanning segments (S1-S6). Inward rectifiers comprise a second family of K+ channels with subunits having two transmembrane domains (M1, M2). Monomers in the third family are proteins containing only one membrane-spanning segment, and they give origin to minK+ channels. Joining together segments S5 and S6 in the case of voltage-gated K+ channels and M1 and M2 in inward rectifiers, there is a highly conserved region with a hairpin shape called the H5 or P region. The P region, the loop connecting the S4 and S5 domains and the S6 transmembrane segment in Shaker-type K+ channels and the COOH-terminal in inward rectifiers, appears to play crucial roles in ion conduction. In Shaker K+ channels the NH2-terminal has been identified as responsible for fast inactivation (N-type inactivation). If the fast-inactivation gate is removed, a slower inactivation process persists, and its rate can be altered by mutations of amino acid residues forming part of the region in the neighborhood of the COOH-terminal (C-type inactivation). In this review we discuss the strategies followed to identify the different structures of K+ channels involved in ion conduction and inactivation processes and how they interplay.

scholarly journals Molecular Determinants of Structural Coupling between C-Type Inactivation and Inner Gate Opening in K + Channels

2017 ◽  
Vol 112 (3) ◽  
pp. 544a
Author(s):  
Jing Li ◽  
Jared Ostmeyer ◽  
Eduardo Perozo ◽  
Benoit Roux
Keyword(s):  
Structural Coupling ◽  
K Channels ◽  
Gate Opening ◽  
Molecular Determinants

scholarly journals Localization and Molecular Determinants of the Hanatoxin Receptors on the Voltage-Sensing Domains of a K+ Channel

2000 ◽  
Vol 115 (6) ◽  
pp. 673-684 ◽  
Author(s):  
Yingying Li-Smerin ◽  
Kenton J. Swartz
Keyword(s):  
K Channel ◽  
Alanine Scanning Mutagenesis ◽  
Voltage Sensing ◽  
Alanine Scanning ◽  
K Channels ◽  
Voltage Gated ◽  
Physical Location ◽  
Molecular Determinants ◽  
Central Pore ◽  
Pore Domain

Hanatoxin inhibits voltage-gated K+ channels by modifying the energetics of activation. We studied the molecular determinants and physical location of the Hanatoxin receptors on the drk1 voltage-gated K+ channel. First, we made multiple substitutions at three previously identified positions in the COOH terminus of S3 to examine whether these residues interact intimately with the toxin. We also examined a region encompassing S1–S3 using alanine-scanning mutagenesis to identify additional determinants of the toxin receptors. Finally, guided by the structure of the KcsA K+ channel, we explored whether the toxin interacts with the peripheral extracellular surface of the pore domain in the drk1 K+ channel. Our results argue for an intimate interaction between the toxin and the COOH terminus of S3 and suggest that the Hanatoxin receptors are confined within the voltage-sensing domains of the channel, at least 20–25 Å away from the central pore axis.

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