The contribution of individual subunits to the coupling of the voltage sensor to pore opening in Shaker K channels: effect of ILT mutations in heterotetramers.
The contribution of individual subunits to the coupling of the voltage sensor to pore opening in Shaker K channels: effect of ILT mutations in heterotetramers.
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DOI：
10.1085/jgp.201010487
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发表时间：
2010-11
期刊：
影响因子：
--
通讯作者：
Bezanilla F
中科院分区：
文献类型：
--
作者：
Gagnon DG;Bezanilla F
电压门控离子通道将电压敏感结构域的构象变化与细胞内门的打开的构象变化偶联以允许离子传导。需要大得多的正电位来将这些构象变化与在S4片段的N-末端处具有并发突变V369 I、I372 L和S376 T（ILT）的Shaker K+通道的门的打开偶联。我们使用切开的卵母细胞电压钳研究了具有不同化学计量的ILT突变的异源四聚体串联通道的生物物理和化学性质。ILT突变体通道的电压敏感结构域需要较小的去极化来激活，但它们的细胞内门不立即跟随电压敏感结构域的运动，需要较大的去极化来打开。我们的研究结果表明，每个亚基的贡献相等的电导-电压的关系，一个单一的ILT-含有亚基是足以诱导一个大的介电和熵的障碍，限制打开细胞内的门。
Voltage-gated ion channels couple conformational change(s) of the voltage-sensing domain to those of the opening of an intracellular gate to allow ionic conduction. Much larger positive potentials are required to couple these conformational changes to the opening of the gate of Shaker K+ channels with the concurrent mutations V369I, I372L, and S376T (ILT) at the N-terminal end of the S4 segment. We used cut-open oocyte voltage clamp to study the biophysical and thermodynamical properties of heterotetrameric concatemerized channels with different stoichiometries of ILT mutations. The voltage-sensing domains of ILT mutant channels require smaller depolarization to activate but their intracellular gate does not immediately follow the movement of the voltage-sensing domain, requiring larger depolarization to open. Our results demonstrate that each subunit contributes equally to the rightward shift of the conductance–voltage relationship and that a single ILT-containing subunit is sufficient to induce a large enthalpic and entropic barrier, limiting opening of the intracellular gate.
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影响因子：
3.8
作者：
Ledwell, JL;Aldrich, RW
通讯作者：
Aldrich, RW
DOI：
10.1085/jgp.112.4.391
发表时间：
1998-10
期刊：
The Journal of general physiology
影响因子：
--
作者：
Cha A;Bezanilla F
通讯作者：
Bezanilla F
影响因子：
16.2
作者：
Aggarwal, SK;MacKinnon, R
通讯作者：
MacKinnon, R
影响因子：
3.4
作者：
HEGINBOTHAM, L;MACKINNON, R
通讯作者：
MACKINNON, R
影响因子：
2.7
作者：
Fisher, CL;Pei, GK
通讯作者：
Pei, GK