Unbiased proteomic and forward genetic screens reveal that mechanosensitive ion channel MSL10 functions at ER-plasma membrane contact sites in Arabidopsis thaliana.
Unbiased proteomic and forward genetic screens reveal that mechanosensitive ion channel MSL10 functions at ER-plasma membrane contact sites in Arabidopsis thaliana.
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DOI：
10.7554/elife.80501
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发表时间：
2022-10-07
期刊：
影响因子：
7.7
通讯作者：
Haswell ES
中科院分区：
文献类型：
--
作者：
Codjoe JM;Richardson RA;McLoughlin F;Vierstra RD;Haswell ES
机械敏感（MS）离子通道是细胞感知机械力并将其转化为离子信号的进化保守方式。拟南芥 MScS-Like (MSL)10 的通道特性已得到充分研究，但 MSL10 信号如何发出仍然很大程度上未知。为了发现 MSL10 的信号传导伙伴，我们采用了蛋白质组筛选和正向遗传筛选；两者都出乎意料地涉及 MSL10 功能中的内质网-质膜接触位点 (EPCS)。蛋白质组筛选显示 MSL10 与多种与 EPCS 相关的蛋白质相关。其中，只有 VAMP 相关蛋白 (VAP)27-1 和 VAP27-3 直接与 MSL10 相互作用。针对功能获得性 MSL10 等位基因（msl10-3G、MSL10S640L）抑制子的正向遗传筛选，鉴定出突触结合蛋白 (SYT)5 和 SYT7 基因的突变。我们还发现，与野生型相比，msl10-3G 植物的叶子中 EPCS 有所扩展。总而言之，这些结果表明 MSL10 与 EPCS 蛋白相关并发挥作用，为理解 MSL10 信号传导提供了新的细胞水平框架。此外，将机械感觉蛋白放置在 EPCS 上可以为这种类型的亚细胞区室的功能和调节提供新的见解。
Mechanosensitive (MS) ion channels are an evolutionarily conserved way for cells to sense mechanical forces and transduce them into ionic signals. The channel properties of Arabidopsis thaliana MscS-Like (MSL)10 have been well studied, but how MSL10 signals remains largely unknown. To uncover signaling partners of MSL10, we employed a proteomic screen and a forward genetic screen; both unexpectedly implicated endoplasmic reticulum–plasma membrane contact sites (EPCSs) in MSL10 function. The proteomic screen revealed that MSL10 associates with multiple proteins associated with EPCSs. Of these, only VAMP-associated proteins (VAP)27-1 and VAP27-3 interacted directly with MSL10. The forward genetic screen, for suppressors of a gain-of-function MSL10 allele (msl10-3G, MSL10S640L), identified mutations in the synaptotagmin (SYT)5 and SYT7 genes. We also found that EPCSs were expanded in leaves of msl10-3G plants compared to the wild type. Taken together, these results indicate that MSL10 associates and functions with EPCS proteins, providing a new cell-level framework for understanding MSL10 signaling. In addition, placing a mechanosensory protein at EPCSs provides new insight into the function and regulation of this type of subcellular compartment.