Graduate College of Biomedical Sciences, Western University of Health Sciences, 309 E. Second St, Pomona, CA, 91766, USA.
College of Pharmacy, Western University of Health Sciences, 309 E. Second St, Pomona, CA, 91766, USA.
Nat Commun. 2018 May 23;9(1):2029. doi: 10.1038/s41467-018-04405-3.
Piezo proteins are transmembrane ion channels which transduce many forms of mechanical stimuli into electrochemical signals. Their pore, formed by the assembly of three identical subunits, opens by an unknown mechanism. Here, to probe this mechanism, we investigate the interaction of Piezo1 with the small molecule agonist Yoda1. By engineering chimeras between mouse Piezo1 and its Yoda1-insensitive paralog Piezo2, we first identify a minimal protein region required for Yoda1 sensitivity. We next study the effect of Yoda1 on heterotrimeric Piezo1 channels harboring wild type subunits and Yoda1-insensitive mutant subunits. Using calcium imaging and patch-clamp electrophysiology, we show that hybrid channels harboring as few as one Yoda1-sensitive subunit exhibit Yoda1 sensitivity undistinguishable from homotrimeric wild type channels. Our results show that the Piezo1 pore remains fully open if only one subunit remains activated. This study sheds light on the gating and pharmacological mechanisms of a member of the Piezo channel family.
压电蛋白是跨膜离子通道，可将多种形式的机械刺激转化为电化学信号。其由三个相同亚基组装而成的孔通过未知机制打开。在这里，为了探究这一机制，我们研究了 Piezo1 与小分子激动剂 Yoda1 的相互作用。通过在小鼠 Piezo1 和其对 Yoda1 不敏感的同源物 Piezo2 之间构建嵌合体，我们首先确定了 Piezo1 对 Yoda1 敏感所需的最小蛋白区域。然后，我们研究了 Yoda1 对含有野生型亚基和 Yoda1 不敏感突变体亚基的异三聚体 Piezo1 通道的影响。通过钙成像和膜片钳电生理学，我们表明，即使只有一个 Yoda1 敏感亚基，嵌合通道也表现出与同三聚体野生型通道几乎相同的 Yoda1 敏感性。我们的结果表明，如果只有一个亚基保持激活，Piezo1 孔仍然完全打开。这项研究揭示了 Piezo 通道家族成员的门控和药理学机制。
