A New Family of Voltage-gated Potassium Channel Regulaory Subunits

描述(申请人提供)：一个新的电压门控钾通道调节亚基家族，在活体内实现电压门控钾(Kv)通道的正常功能需要辅助亚基和调节修饰。原因是显而易见的。辅助亚基和调节修饰(如磷酸化)改变形成孔的亚基，以决定混合复合体的组织特异性蛋白质表达、门控动力学、单位电导、离子选择性、调节和药理学。因此，与疾病相关的辅助亚单位和调控基序的突变被认为会导致危及生命的心律失常、癫痫等神经肌肉疾病和周期性瘫痪。这一应用是基于我们最近的工作，证明了普遍存在的小的泛素相关修饰蛋白(SUMOS，-100氨基酸)是一类未知的辅助亚基，通过质膜上的可逆共价修饰来调节钾通道。这一应用是基于初步数据表明，相扑通过修改和调节Kv2.1、Kv4.3和KChlP2直接影响激发。这些研究试图描述这些Kv通道的机制细节，并通过实验细胞的克隆通道和大鼠大脑原代细胞的自然电流来阐明对生理学的影响。我们认为，通过总合作用调节Kv通道值得这样仔细研究，因为(A)它似乎对正常生理很重要；(B)离子通道调节的新机制将被阐明；以及(C)对辅助亚基/调节修饰的研究一直是诊断和治疗干预以改善人类健康的基础。这项经修订的申请旨在解决第一个审查周期中提出的关切。

DESCRIPTION (provided by applicant): A New Family of Voltage-gated Potassium Channel Regulatory Subunits Accessory subunits and regulatory modifications are required to achieve normal function of voltage-gated potassium (Kv) channels in vivo. The reasons are clear. Accessory subunits and regulatory modifications (such as phosphorylation) alter pore-forming subunits to determine tissue specific protein expression, gating kinetics, unitary conductance, ion selectivity, regulation and pharmacology of mixed complexes. Thus, disease-associated mutations in accessory subunits and regulatory motifs have been seen to cause life- threatening cardiac arrhythmias, neuromuscular diseases like epilepsy and periodic paralysis. This application is based on our recent work demonstrating that the ubiquitous, small, ubiquitin-related modifier proteins (SUMOs, -100 amino acids) are an unrecognized class of accessory subunits that regulate potassium channels by reversible covalent modification in the plasma membrane. This application is based on preliminary data indicating that SUMOs directly influence excitation by modification and regulation of the Kv2.1, Kv4.3 and KChlP2. The proposed studies seek to describe regulation of these Kv channels by the SUMO pathway in mechanistic detail and to elucidate effects on physiology through experiments of cloned channels in experimental cells and native currents in primary cells from rat brain. We argue Kv channel regulation by sumoylation merits such scrutiny because (a) it appears to be important to normal physiology; (b) a new mechanism of ion channel regulation will be elucidated; and, (c) studies of accessory subunits/regulatory modifications have been the basis for diagnostic and therapeutic interventions to improve human health. This revised application seeks to address concerns raised in the first review cycle.