Localization and Regulation of Shal (Kv4) Potassium Channels

描述（由申请人提供）：我们的长期兴趣是了解离子通道如何定位于特定的亚细胞位点并受到特定蛋白质相互作用物的调节。在这项资助提案中，我们重点关注电压门控 K 通道 Shal (Kv4)，它与设置中枢模式发生器的节律性放电、学习和记忆以及塑造心脏动作电位有关。因此，了解 Shal K 通道定位和调节的机制对于心脏和中枢神经系统的生命过程具有重要意义。我们的初步研究重点是果蝇 Shal 通道的两个新发现的相互作用因子 K30 和 K29。两种相互作用因子主要在神经系统中表达，与 Shal 通道共定位，并与 Shal 通道的 C 末端表现出强而特异性的结合。有趣的是，K29 与哺乳动物 Shal 通道树突靶向所需的高度保守基序结合，表明 K29 是 Shal 通道定位的关键调节因子。我们将表征 Shal-K30 和 Shal-K29 相互作用，并检查 K30 和 K29 在体内 Shal 通道的亚细胞定位和调节中的功能。使用果蝇作为模型系统将使我们能够结合遗传、电生理学、细胞和分子生物学方法来研究所有已识别的相互作用因子如何在 Shal 通道的调节和亚细胞定位中发挥作用。由于确定的策略和蛋白质可能在哺乳动物中保守，因此我们的研究结果预计不仅对于了解果蝇离子通道具有重要意义，而且对于哺乳动物系统也具有重要意义。与公共卫生的相关性：离子通道是形成神经系统中电和化学通讯的基本组成部分，离子通道的功能高度依赖于其亚细胞定位和调节。当离子通道定位错误或调节不当时，后果往往很严重，导致癫痫、阵发性共济失调、周期性麻痹、肌强直和长 QT 综合征等病症。因此，了解离子通道如何调节和定位于亚细胞区室可能会对这些疾病的预防和治疗提供重要的见解。

DESCRIPTION (provided by applicant): Our long-term interest is to understand how ion channels are localized to particular sub-cellular sites and regulated by specific protein interactors. In this grant proposal, we focus on the voltage-gated K+ channel, Shal (Kv4), which has been implicated in setting the rhythmic firing of central pattern generators, learning and memory, and shaping the cardiac action potential. Therefore, understanding the mechanisms of Shal K+ channel localization and regulation has important implications for vital processes in the heart and central nervous system. We focus our initial studies on two newly identified interactors, K30 and K29, of Drosophila Shal channels. Both interactors are expressed primarily in the nervous system, co-localize with Shal channels, and exhibit strong and specific binding to the C-terminus of Shal channels. Interestingly, K29 binds to a highly conserved motif required for dendritic targeting of mammalian Shal channels, implicating K29 as a key regulator of Shal channel localization. We will characterize Shal-K30 and Shal-K29 interactions and examine the function of K30 and K29 in the subcellular localization and regulation of Shal channels in vivo. Using Drosophila as a model system will allow us to combine genetic, electrophysiological, cell and molecular biological approaches to study how all identified interactors function in the regulation and subcellular localization of Shal channels. Since strategies and proteins identified are likely to be conserved in mammals, our findings are expected to be significant not only for understanding Drosophila ion channels, but also for mammalian systems. Relevance to public health: Ion channels are the basic components that shape electrical and chemical communication in the nervous system, and the function of ion channels is highly dependent on their subcellular localization and regulation. When ion channels are mis-localized or mis-regulated, consequences are often severe, resulting in conditions such as epilepsy, episodic ataxia, periodic paralysis, myotonia, and Long QT syndrome. Therefore, understanding how ion channels are regulated and localized to subcellular compartments is likely to give important insights into the prevention and treatment of these conditions.