Removal of the mechanoprotective influence of the cytoskeleton reveals PIEZO1 is gated by bilayer tension.
Removal of the mechanoprotective influence of the cytoskeleton reveals PIEZO1 is gated by bilayer tension.
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DOI：
10.1038/ncomms10366
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发表时间：
2016-01-20
影响因子：
16.6
通讯作者：
Martinac B
中科院分区：
文献类型：
--
作者：
Cox CD;Bae C;Ziegler L;Hartley S;Nikolova-Krstevski V;Rohde PR;Ng CA;Sachs F;Gottlieb PA;Martinac B
机械敏感性离子通道是将机械刺激与离子通量耦合的力转导酶。理解机械敏感通道的门控机制是具有挑战性的，因为通道所看到的刺激反映了膜、细胞骨架和细胞外基质之间共享的力。在这里，我们检查是否机械敏感通道PIEZO 1被激活的力通过双层传输。为了实现这一点，我们产生了基本上不含细胞骨架的HEK 293细胞膜泡。使用细菌通道MscL，我们校准双层张力，证明MscL在水泡中的激活与在重构双层中的激活相同。利用一种新的PIEZO 1-GFP融合，我们然后显示PIEZO 1被激活的气泡膜中的双层张力，门控在较低的压力指示皮质细胞骨架的去除和它提供的mechanoprotection。因此，PIEZO 1通道必须感知直接通过双层传递的力。 PIEZO 1是一种机械敏感性离子通道，但力传递的机制尚不清楚。在这里，考克斯和Bae等人破坏了HEK 293细胞中的皮质细胞骨架，以表明PIEZO 1直接通过膜张力门控。
Mechanosensitive ion channels are force-transducing enzymes that couple mechanical stimuli to ion flux. Understanding the gating mechanism of mechanosensitive channels is challenging because the stimulus seen by the channel reflects forces shared between the membrane, cytoskeleton and extracellular matrix. Here we examine whether the mechanosensitive channel PIEZO1 is activated by force-transmission through the bilayer. To achieve this, we generate HEK293 cell membrane blebs largely free of cytoskeleton. Using the bacterial channel MscL, we calibrate the bilayer tension demonstrating that activation of MscL in blebs is identical to that in reconstituted bilayers. Utilizing a novel PIEZO1–GFP fusion, we then show PIEZO1 is activated by bilayer tension in bleb membranes, gating at lower pressures indicative of removal of the cortical cytoskeleton and the mechanoprotection it provides. Thus, PIEZO1 channels must sense force directly transmitted through the bilayer. PIEZO1 is a mechanosensitive ion channel, but the mechanism of force transduction is unknown. Here Cox and Bae et al. disrupt the cortical cytoskeleton in HEK293 cells to show that PIEZO1 is gated directly by membrane tension.