Cryo-EM structures of cardiac thin filaments reveal the 3D architecture of troponin
Cryo-EM structures of cardiac thin filaments reveal the 3D architecture of troponin
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DOI：
10.1016/j.jsb.2020.107450
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发表时间：
2020-03-01
影响因子：
3
通讯作者：
Wakabayashi, Takeyuki
中科院分区：
文献类型：
--
作者：
Oda, Toshiyuki;Yanagisawa, Haruaki;Wakabayashi, Takeyuki
肌钙蛋白是横纹肌的重要成分，它以钙依赖的方式调节肌动球蛋白系统的滑动。尽管肌钙蛋白很重要，但由于其高度的结构异质性，其结构一直难以捉摸。在这项研究中，我们使用配备Volta相位板(VPP)的冷冻电子显微镜分析了小鼠心脏细丝的三维结构。VPP的对比度增强使我们能够重建细丝的整个重复。我们确定了肌钙蛋白相对于F-肌动蛋白和原肌球蛋白的方向，并表征了肌钙蛋白和原肌球蛋白之间的相互作用。本研究为了解肌动球蛋白系统的分子机制提供了结构基础。
Troponin is an essential component of striated muscle and it regulates the sliding of actomyosin system in a calcium-dependent manner. Despite its importance, the structure of troponin has been elusive due to its high structural heterogeneity. In this study, we analyzed the 3D structures of murine cardiac thin filaments using a cryo-electron microscope equipped with a Volta phase plate (VPP). Contrast enhancement by a VPP enabled us to reconstruct the entire repeat of the thin filament. We determined the orientation of troponin relative to F-actin and tropomyosin, and characterized the interactions between troponin and tropomyosin. This study provides a structural basis for understanding the molecular mechanism of actomyosin system.