Stereocilia Membrane Deformation: Implications for the Gating Spring and Mechanotransduction Channel
Stereocilia Membrane Deformation: Implications for the Gating Spring and Mechanotransduction Channel
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DOI：
10.1016/j.bpj.2011.12.022
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发表时间：
2012-01-18
影响因子：
3.4
通讯作者：
Spector, Alexander A.
中科院分区：
文献类型：
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作者：
Powers, Richard J.;Roy, Sitikantha;Spector, Alexander A.
在毛细胞中，虽然机械转导通道已被定位于机械敏感的毛束的较短静纤毛的尖端，但对力如何传递到通道知之甚少。在这里，我们使用的膜通道复合物的生物物理模型来分析门控弹簧的顺应性和通道安排的性质。我们使用一个三角形的表面模型和蒙特卡罗模拟计算下的尖端链接力的作用下的膜的变形。我们表明，根据门控弹簧的刚度，门控弹簧的顺应性组件产生的膜单独或膜和连接通道的肌动蛋白细胞骨架的系绳的组合。如果束的特征在于相对软的门控弹簧，例如牛蛙球囊的门控弹簧，则通过通道栓系对膜增强的需要取决于膜参数。对于更硬的门控弹簧，例如来自大鼠外毛细胞的门控弹簧，通道必须被束缚用于膜的所有生物病理学现实参数。我们计算膜力（合力）。其取决于膜张力、弯曲模量和曲率，并且表明它们可以决定通道的命运。
In hair cells, although mechanotransduction channels have been localized to tips of shorter stereocilia of the mechanically sensitive hair bundle, little is known about how force is transmitted to the channel. Here, we use a biophysical model of the membrane-channel complex to analyze the nature of the gating spring compliance and channel arrangement. We use a triangulated surface model and Monte Carlo simulation to compute the deformation of the membrane under the action of tip link force. We show that depending on the gating spring stiffness, the compliant component of the gating spring arises from either the membrane alone or a combination of the membrane and a tether that connects the channel to the actin cytoskeleton. If a bundle is characterized by relatively soft gating springs, such as those of the bullfrog sacculus, the need for membrane reinforcement by channel tethering then depends on membrane parameters. With stiffer gating springs, such as those from rat outer hair cells, the channel must be tethered for all biophysically realistic parameters of the membrane. We compute the membrane forces (resultants),. which depend on membrane tension, bending modulus, and curvature, and show that they can determine the fate of the channel.