Research School of Biology, Australian National University, Acton, Canberra, Australia.
Victor Chang Cardiac Research Institute, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, Darlinghurst, New South Wales, Australia.
Biophys J. 2020 Oct 20;119(8):1683-1697. doi: 10.1016/j.bpj.2020.07.043. Epub 2020 Sep 2.
Touch, hearing, and blood pressure regulation require mechanically gated ion channels that convert mechanical stimuli into electrical currents. One such channel is Piezo1, which plays a key role in the transduction of mechanical stimuli in humans and is implicated in diseases, such as xerocytosis and lymphatic dysplasia. There is building evidence that suggests Piezo1 can be regulated by the membrane environment, with the activity of the channel determined by the local concentration of lipids, such as cholesterol and phosphoinositides. To better understand the interaction of Piezo1 with its environment, we conduct simulations of the protein in a complex mammalian bilayer containing more than 60 different lipid types together with electrophysiology and mutagenesis experiments. We find that the protein alters its local membrane composition, enriching specific lipids and forming essential binding sites for phosphoinositides and cholesterol that are functionally relevant and often related to Piezo1-mediated pathologies. We also identify a number of key structural connections between the propeller and pore domains located close to lipid-binding sites.
触摸、听觉和血压调节都需要机械门控离子通道,将机械刺激转化为电流。其中一种通道是 Piezo1,它在人类机械刺激转导中起着关键作用,并与疾病有关,如干血球症和淋巴管发育不良。越来越多的证据表明 Piezo1 可以受到膜环境的调节,通道的活性取决于胆固醇和磷脂酰肌醇等脂质的局部浓度。为了更好地了解 Piezo1 与其环境的相互作用,我们在含有 60 多种不同脂质类型的复杂哺乳动物双层膜中对该蛋白进行模拟,并结合电生理学和突变实验。我们发现该蛋白改变了其局部膜组成,使特定脂质富集,并形成了对磷脂酰肌醇和胆固醇的必需结合位点,这些结合位点具有功能相关性,并且常常与 Piezo1 介导的病理学有关。我们还确定了靠近脂质结合位点的螺旋桨和孔域之间的一些关键结构连接。