溶酶体透通道TRPML3的冷电子显微镜结构
Marscha Hirschi1, Mark A Herzik2, Jinhong Wie3
1Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, USA.
Nature
|October 12, 2017
概括
TRPML3通道的结构揭示了粘脂蛋白域如何与酸-3,5-双酸盐 (PtdIns(3,5) P2结合,以激活 (Ca2+) 流动. 这一发现澄清了依赖脂质的TRPML通道封闭的机制.
科学领域:
- 细胞信号传输
- 离子通道功能
- 脂质与蛋白质的相互作用
背景情况:
- 暂时受体潜在粘脂蛋白 (TRPML) 道是晚期内分体和溶解体上的关键Ca2+透道.
- TRPMLs调节器官功能,并与IV型粘脂症等疾病有关.
- 脂质调节,特别是酸丁-3,5-双酸盐 (PtdIns(3,5) P2),对于TRPML通道活性至关重要.
研究的目的:
- 阐明PtdIns的结构基础{3,5) P2介导的TRPML通道激活.
- 通过TRPML通道了解Ca2+导电性的机制.
- 研究N端区域在脂质结合和道结合中的作用.
主要方法:
- 用冷电子显微镜 (cryo-EM) 确定TRPML3通道的结构.
- 功能性研究以评估道活性和脂质相互作用.
- 对参与脂质结合和道封闭的保存残留物进行分析.
主要成果:
- 确定了普通鱼TRPML3通道的2. 9 Å冷电磁结构.
- 一个称为粘脂蛋白域的新细胞域被确定并与孔隙联系在一起.
- 粘脂蛋白域被提议是PtdIns ((3,5) P2结合和激活的主要部位,作为一个"轮".
结论:
- 该结构为离子导电和TRPML通道的独特架构提供了分子基础.
- 粘脂蛋白域在感知PtdIns ((3,5) P2和关闭通道方面发挥着关键作用.
- 这项工作促进了我们对依赖脂质的离子通道调节及其生理相关性的理解.
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