Rectification of voltage-gated plant K+ channels

植物电压门控K+通道家族在植物对土壤钾的吸收及其在整个植物中的分布中起着重要作用。有趣的是，该家族的成员在结构上非常相似，但在功能上它们分为允许植物细胞积累K+的内向整流（Kin）通道和介导K+外排的外向整流（Kout）通道。这种分歧的原因尚不清楚。我们生成了一个合成Kin通道（SKIN）和一个合成Kout通道（SKOUT），它们具有很高的同源率（在蛋白质水平上为82.5%，在DNA水平上为90%）。合成SKIN和SKOUT克隆的设计使我们能够进一步生成一个含有100 000 000 000个不同的SKIN/SKOUT嵌合体的cDNA文库。这个文库将被用来识别向内或向外校正的嵌合体，以便进一步增加这两种通道类型之间的识别程度。实验工作伴随着硅分子模型和动力学模拟。这种结合的方法是新颖的，将允许对植物K+通道的调节进行详细的结构和功能研究。此外，它将为尝试在计算机上设计具有定义特征的膜蛋白提供翔实的数据。

The family of voltage-gated K+ channels in plants plays an important role in the uptake of potassium from the soil and its distribution throughout the plant. Interestingly, members of this family are structurally very similar but functionally they segregate into inward-rectifying (Kin) channels that allow plant cells to accumulate K+ and outward-rectifying (Kout) channels that mediate K+ efflux. The reason for this divergence is unknown. We generated a synthetic Kin channel (SKIN) and a synthetic Kout channel (SKOUT) that share a high rate of identity (82.5% at the protein level, 90% at the DNA level). The design of the synthetic SKIN and SKOUT clones allowed us further to generate a cDNA library with >30.000.000 different SKIN/SKOUT chimeras. This library will be used to identify chimeras that are inward- or outward-rectifying in order to further increase the degree of identity between these two channel types. The experimental work is accompanied by in silico molecular modeling and dynamics simulations. This combined approach is novel and will allow detailed structural and functional insights into the regulation of plant K+ channels. Furthermore, it will provide informative data for the attempt to design membrane proteins with defined features at the computer.