The role of MscL amphipathic N terminus indicates a blueprint for bilayer-mediated gating of mechanosensitive channels.
The role of MscL amphipathic N terminus indicates a blueprint for bilayer-mediated gating of mechanosensitive channels.
复制标题
DOI：
10.1038/ncomms11984
复制
发表时间：
2016-06-22
影响因子：
16.6
通讯作者：
Martinac B
中科院分区：
文献类型：
--
作者：
Bavi N;Cortes DM;Cox CD;Rohde PR;Liu W;Deitmer JW;Bavi O;Strop P;Hill AP;Rees D;Corry B;Perozo E;Martinac B
由于机械力从脂质双层直接传递到通道，细菌机械敏感通道 MscL 响应膜张力而进行门控。 MscL 代表了研究机械感觉转导基本生物物理原理的优秀模型系统。然而，对将双层张力转换为通道门控的基本结构成分的理解仍然不完整。在这里，我们使用多种实验和计算方法，证明 MscL 的两亲性 N 端螺旋在张力诱导的门控过程中充当关键的结构元件，既稳定关闭状态，又将通道与膜耦合。我们认为这也可能代表了不相关的机械敏感离子通道的门控循环中的共同原理，允许通道构象与膜动力学的耦合。 细菌机械敏感通道的激活仍未完全了解。在这里，巴维等人。结果表明，MscL 的 N 末端螺旋动态地将膜张力与通道门控耦合，表明高等生物离子通道的机械敏感性背后存在保守机制。
The bacterial mechanosensitive channel MscL gates in response to membrane tension as a result of mechanical force transmitted directly to the channel from the lipid bilayer. MscL represents an excellent model system to study the basic biophysical principles of mechanosensory transduction. However, understanding of the essential structural components that transduce bilayer tension into channel gating remains incomplete. Here using multiple experimental and computational approaches, we demonstrate that the amphipathic N-terminal helix of MscL acts as a crucial structural element during tension-induced gating, both stabilizing the closed state and coupling the channel to the membrane. We propose that this may also represent a common principle in the gating cycle of unrelated mechanosensitive ion channels, allowing the coupling of channel conformation to membrane dynamics. The activation of bacterial mechanosensitive channels is still not fully understood. Here, Bavi et al. show that the N-terminal helix of MscL dynamically couples membrane tension to channel gating, suggesting a conserved mechanism underlying the mechanosensitivity of ion channels of higher organisms.