Fast inactivation in Shaker K+ channels. Properties of ionic and gating currents.
Fast inactivation in Shaker K+ channels. Properties of ionic and gating currents.
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在振动振动器K+通道中快速失活。离子和门控电流的性质。
DOI：
10.1085/jgp.111.5.625
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发表时间：
1998-05
影响因子：
3.8
通讯作者：
Stefani, E
中科院分区：
文献类型：
--
作者：
Roux, MJ;Olcese, R;Toro, L;Bezanilla, F;Stefani, E
快速失活 Shaker H4 钾通道和非传导孔突变体 Shaker H4 W434F 通道已被用于将离子电流快速失活的安装和恢复与称为“电荷固定”的门控电流动力学变化相关联（Armstrong，C.M. 和 F. Bezanilla. 1977. J. Gen. Physiol. 70:567–590.）。 Shaker H4 W434F 门控电流与无钾溶液中记录的导电克隆的门控电流非常相似。这种突变通道允许记录总门控电荷返回，即使是从很大程度上使传导通道失活的电位返回时也是如此。随着去极化电势的增加，-90 mV 返回电势下的关断选通电流衰减阶段从单个快速分量变为至少两个分量，较慢的需要约 200 ms 才能完全充电返回。电荷固定开始和离子电流衰减具有相同的时间过程。 2 mM 外部钾中的门控电流 (Shaker H4 W434F) 和离子电流 (Shaker H4) 的回收率至少有两个分量。两种恢复率在 -120 和 -90 mV 下相似。相反，在较高电势（-70 和 -50 mV）下，门控电荷的恢复速度明显慢于离子电流。具有单个失活状态的模型无法解释我们所有的数据，这有力地支持了“并行”失活状态的存在。在此模型中，当通道孔被 NH2 末端区域占据时，一部分电荷可以在复极化时恢复。
Fast inactivating Shaker H4 potassium channels and nonconducting pore mutant Shaker H4 W434F channels have been used to correlate the installation and recovery of the fast inactivation of ionic current with changes in the kinetics of gating current known as “charge immobilization” (Armstrong, C.M., and F. Bezanilla. 1977. J. Gen. Physiol. 70:567–590.). Shaker H4 W434F gating currents are very similar to those of the conducting clone recorded in potassium-free solutions. This mutant channel allows the recording of the total gating charge return, even when returning from potentials that would largely inactivate conducting channels. As the depolarizing potential increased, the OFF gating currents decay phase at −90 mV return potential changed from a single fast component to at least two components, the slower requiring ∼200 ms for a full charge return. The charge immobilization onset and the ionic current decay have an identical time course. The recoveries of gating current (Shaker H4 W434F) and ionic current (Shaker H4) in 2 mM external potassium have at least two components. Both recoveries are similar at −120 and −90 mV. In contrast, at higher potentials (−70 and −50 mV), the gating charge recovers significantly more slowly than the ionic current. A model with a single inactivated state cannot account for all our data, which strongly support the existence of “parallel” inactivated states. In this model, a fraction of the charge can be recovered upon repolarization while the channel pore is occupied by the NH2-terminus region.
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DOI：
10.1073/pnas.85.15.5723
发表时间：
1988-08-01
影响因子：
11.1
作者：
IVERSON, LE;TANOUYE, MA;RUDY, B
通讯作者：
RUDY, B
影响因子：
56.9
作者：
HOSHI, T;ZAGOTTA, WN;ALDRICH, RW
通讯作者：
ALDRICH, RW
影响因子：
56.9
作者：
SIGG, D;STEFANI, E;BEZANILLA, F
通讯作者：
BEZANILLA, F
影响因子：
3.4
作者：
VANDENBERG, CA;BEZANILLA, F
通讯作者：
BEZANILLA, F
振动钾通道中的W434F突变阻滞电流如何？
影响因子：
3.8
作者：
Yang, Y;Yan, Y;Sigworth, F J
通讯作者：
Sigworth, F J