Intermediate state trapping of a voltage sensor.
Intermediate state trapping of a voltage sensor.
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DOI：
10.1085/jgp.201210827
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发表时间：
2012-12
期刊：
影响因子：
--
通讯作者：
Bezanilla F
中科院分区：
文献类型：
--
作者：
Lacroix JJ;Pless SA;Maragliano L;Campos FV;Galpin JD;Ahern CA;Roux B;Bezanilla F
电压传感器域（VSD）通过依赖于膜电信号经历构象变化来调节离子通道和酶。VSD转变的分子机制尚未完全了解。在这里，我们表明，一些突变的I241在S1段的振动Kv通道正移的VSD运动的电压依赖性和改变VSD和孔域之间的功能耦合。在I241突变体中，I241W在激活和失活过程中固定了VSD运动，大约在静息和激活状态之间的一半，并大幅改变了离子电导的电压激活。这种表型，这是一个稳定的中间VSD构象的I241W突变一致，减少了电荷保守的R2K突变，但不是由电荷中和R2Q突变。有趣的是，这些效应中的大多数是由位于I241上方一个螺旋转角的F244W突变再现的。使用非天然吲哚衍生物的电生理记录排除了阳离子-N-色氨酸相互作用对插入位置I241和F244的通道电导的影响，但表明吲哚氮对I241W表型很重要。洞察负责稳定的中间状态的分子机制进行了研究，通过创建在硅片中的突变I241W，I241W/R2K，和F244W的中间构象从计算VSD过渡途径使用弦方法确定。实验结果和计算分析表明，I241W的表型可能起源于吲哚氮原子与R2的骨架羰基之间形成氢键。这项工作提供了新的信息，在电压门控离子通道的中间状态的方法，产生最小的化学扰动。
Voltage sensor domains (VSDs) regulate ion channels and enzymes by undergoing conformational changes depending on membrane electrical signals. The molecular mechanisms underlying the VSD transitions are not fully understood. Here, we show that some mutations of I241 in the S1 segment of the Shaker Kv channel positively shift the voltage dependence of the VSD movement and alter the functional coupling between VSD and pore domains. Among the I241 mutants, I241W immobilized the VSD movement during activation and deactivation, approximately halfway between the resting and active states, and drastically shifted the voltage activation of the ionic conductance. This phenotype, which is consistent with a stabilization of an intermediate VSD conformation by the I241W mutation, was diminished by the charge-conserving R2K mutation but not by the charge-neutralizing R2Q mutation. Interestingly, most of these effects were reproduced by the F244W mutation located one helical turn above I241. Electrophysiology recordings using nonnatural indole derivatives ruled out the involvement of cation-Π interactions for the effects of the Trp inserted at positions I241 and F244 on the channel’s conductance, but showed that the indole nitrogen was important for the I241W phenotype. Insight into the molecular mechanisms responsible for the stabilization of the intermediate state were investigated by creating in silico the mutations I241W, I241W/R2K, and F244W in intermediate conformations obtained from a computational VSD transition pathway determined using the string method. The experimental results and computational analysis suggest that the phenotype of I241W may originate in the formation of a hydrogen bond between the indole nitrogen atom and the backbone carbonyl of R2. This work provides new information on intermediate states in voltage-gated ion channels with an approach that produces minimum chemical perturbation.
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影响因子：
16.2
作者：
Aggarwal, SK;MacKinnon, R
通讯作者：
MacKinnon, R
DOI：
10.1085/jgp.201010573
发表时间：
2011-05
期刊：
The Journal of general physiology
影响因子：
--
作者：
Haddad GA;Blunck R
通讯作者：
Blunck R
DOI：
10.1073/pnas.0806486105
发表时间：
2008-09-30
影响因子：
11.1
作者：
DeCaen, Paul G.;Yarov-Yarovoy, Vladimir;Catterall, William A.
通讯作者：
Catterall, William A.
影响因子：
5.5
作者：
Jacobson, David A.;Mendez, Felipe;Philipson, Louis H.
通讯作者：
Philipson, Louis H.
影响因子：
4.4
作者：
JORGENSEN, WL;CHANDRASEKHAR, J;KLEIN, ML
通讯作者：
KLEIN, ML