Selectivity filter gating in homomeric and heteromeric K+ channels

在第一个资助期内，我们发现了一种新的药理学激活机制，为不同类型的K+通道（K2 P通道，BK通道和hERG通道）中的选择性过滤器（SF）门控机制提供了新的见解。我们还描述了TWIK通道中不寻常的离子通量门控机制，并有助于识别ASK-1/3通道中的变构抑制剂位点。所产生的洞察力展示了功能研究和MD模拟相结合的力量，作为该研究单元的中心目的。在这里，我们建议调查的药理学和生理机制，控制（SF）门在各种K+通道。具体目标包括：（1）表征异聚体K2 P通道以及（2）Slo 2、TOK-1和MthK通道中目前未探索的药理学和SF门控特性，（3）TREK-1通道中更全局的门控转换，（4）近端C末端在K2 P通道门控中的作用;（5）SF与螺旋束交叉门控在各种K+通道中的耦合。这些研究包括电生理学（膜片钳和双层），诱变（经典和非天然氨基酸）和荧光测量在我们这边，将全面补充MD模拟由H。Sun（P3）和B. de Groot/W.克努特（P5）。

During the first funding period we discovered a novel pharmacological activation mechanism that provided new insight into the mechanism of selectivity filter (SF) gating in different classes of K+ channels (K2P channels, BK channels and hERG channels). We also characterized the unusual ion flux gating mechanism in TWIK channels and contributed to the identification of an allosteric inhibitor site in TASK-1/3 channels. The generated insight showcases the power of combining functional studies and MD simulations as the central purpose of this Research Unit. Here we propose to investigate the pharmacological and physiological mechanisms that control the (SF) gate in various K+ channels. The specific aims include (1) the characterization of the currently unexplored pharmacological and SF gating properties in heteromeric K2P channels as well as (2) in Slo2, TOK-1 and MthK channels, (3) the more global gating transitions in TREK-1 channels, (4) the role of the proximal C-terminus in K2P channel gating and (5) the coupling between SF and helix bundle crossing gate in various K+ channels. These investigations include electrophysiology (patch clamp and bilayer), mutagenesis (classical and unnatural amino acid) and fluorescence measurements on our side that will be comprehensively complemented by MD simulations performed by H. Sun (P3) and B. de Groot/W. Kopec (P5).