Mechanosensitive pore opening of a prokaryotic voltage-gated sodium channel.
Mechanosensitive pore opening of a prokaryotic voltage-gated sodium channel.
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DOI：
10.7554/elife.79271
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发表时间：
2023-03-13
期刊：
影响因子：
7.7
通讯作者：
Beyder A
中科院分区：
文献类型：
--
作者：
Strege PR;Cowan LM;Alcaino C;Mazzone A;Ahern CA;Milescu LS;Farrugia G;Beyder A
电压门控离子通道（VGIC）协调电活动，驱动心脏和肠道等收缩组织的机械功能。反过来，收缩改变膜张力并影响离子通道。VGIC是机械敏感的，但机械敏感性的机制仍然知之甚少。在这里，我们利用相对简单的NaChBac，原核细胞的电压门控钠通道从耐盐芽孢杆菌，调查机械敏感性。在异源转染HEK293细胞的全细胞实验中，剪切应力可逆地改变了NaChBac的动力学特性，并增加了其最大电流，与机械敏感性真核钠通道NaV1.5相反。在单通道实验中，贴片抽吸可逆地增加了一个NaChBac突变体的开放概率与失活删除。一个简单的动力学机制，机械敏感的孔开放过渡解释了整体响应力，而另一种模型与机械敏感的电压传感器激活偏离的数据。NaChBac的结构分析确定了铰链细胞内门的大位移，铰链附近的诱变减少了NaChBac的机械敏感性，进一步支持了所提出的机制。我们的研究结果表明，NaChBac是整体mechanosensitive由于mechanosensitivity的电压不敏感的门控步骤与孔开放。这种机制可能适用于真核VGIC，包括NaV1.5。
Voltage-gated ion channels (VGICs) orchestrate electrical activities that drive mechanical functions in contractile tissues such as the heart and gut. In turn, contractions change membrane tension and impact ion channels. VGICs are mechanosensitive, but the mechanisms of mechanosensitivity remain poorly understood. Here, we leverage the relative simplicity of NaChBac, a prokaryotic voltage-gated sodium channel from Bacillus halodurans, to investigate mechanosensitivity. In whole-cell experiments on heterologously transfected HEK293 cells, shear stress reversibly altered the kinetic properties of NaChBac and increased its maximum current, comparably to the mechanosensitive eukaryotic sodium channel NaV1.5. In single-channel experiments, patch suction reversibly increased the open probability of a NaChBac mutant with inactivation removed. A simple kinetic mechanism featuring a mechanosensitive pore opening transition explained the overall response to force, whereas an alternative model with mechanosensitive voltage sensor activation diverged from the data. Structural analysis of NaChBac identified a large displacement of the hinged intracellular gate, and mutagenesis near the hinge diminished NaChBac mechanosensitivity, further supporting the proposed mechanism. Our results suggest that NaChBac is overall mechanosensitive due to the mechanosensitivity of a voltage-insensitive gating step associated with the pore opening. This mechanism may apply to eukaryotic VGICs, including NaV1.5.
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DOI：
10.1085/jgp.201210779
发表时间：
2012-06
期刊：
The Journal of general physiology
影响因子：
--
作者：
Lee S;Goodchild SJ;Ahern CA
通讯作者：
Ahern CA
DOI：
10.4161/chan.21202
发表时间：
2012-07
期刊：
Channels (Austin, Tex.)
影响因子：
--
作者：
Beyder A;Strege PR;Bernard C;Farrugia G
通讯作者：
Farrugia G
影响因子：
3.3
作者：
Cowan, Luke M.;Strege, Peter R.;Rusinova, Radda;Andersen, Olaf S.;Farrugia, Gianrico;Beyder, Arthur
通讯作者：
Beyder, Arthur
DOI：
10.1085/jgp.201711911
发表时间：
2018-02-05
期刊：
The Journal of general physiology
影响因子：
--
作者：
Salari A;Navarro MA;Milescu M;Milescu LS
通讯作者：
Milescu LS
影响因子：
16.6
作者：
通讯作者：
--