A vesicle-trafficking protein commandeers Kv channel voltage sensors for voltage-dependent secretion
A vesicle-trafficking protein commandeers Kv channel voltage sensors for voltage-dependent secretion
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DOI：
10.1038/nplants.2015.108
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发表时间：
2015-08-03
期刊：
影响因子：
18
通讯作者：
Blatt, Michael R.
中科院分区：
文献类型：
--
作者：
Grefen, Christopher;Karnik, Rucha;Blatt, Michael R.
植物的生长取决于渗透溶质吸收的离子转运和分泌膜运输，以输送细胞壁重塑和细胞扩张的物质。这些过程的协调是植物如何调节细胞体积和膨压的问题的核心，这个问题已经解决了世纪。在这里，我们报告的陷阱蛋白SYP 121（SYR 1/PEN 1），介导的囊泡融合在拟南芥质膜，结合电压传感器域（VSD）的K+通道，赋予电压依赖性的分泌交通与K+摄取平行。VSD结合增强了受电压影响的体内分泌，并且影响VSD构象的突变与通道门控、净K+浓度、渗透含量和生长平行地改变结合和分泌。这些结果表明，一个新的和意想不到的机制，分泌控制，其中一个子集的植物SNARE征用K+通道VSD协调膜运输与K+吸收的增长。
Growth in plants depends on ion transport for osmotic solute uptake and secretory membrane trafficking to deliver material for wall remodelling and cell expansion. The coordination of these processes lies at the heart of the question, unresolved for more than a century, of how plants regulate cell volume and turgor. Here we report that the SNARE protein SYP121 (SYR1/PEN1), which mediates vesicle fusion at the Arabidopsis plasma membrane, binds the voltage sensor domains (VSDs) of K+ channels to confer a voltage dependence on secretory traffic in parallel with K+ uptake. VSD binding enhances secretion in vivo subject to voltage, and mutations affecting VSD conformation alter binding and secretion in parallel with channel gating, net K+ concentration, osmotic content and growth. These results demonstrate a new and unexpected mechanism for secretory control, in which a subset of plant SNAREs commandeer K+ channel VSDs to coordinate membrane trafficking with K+ uptake for growth.