DISTRIBUTION AND STRUCTURE OF HERG POTASSIUM CHANNELS

HERG已被确定为一种形式的长QT综合征的基因座， LQT2，可导致心律失常，经常导致猝发 死亡。HERG的异源表达导致钾电流非常 与内源性钾电流Ikr相似(但不完全相同) 有助于人类心脏的复极。这样做的目的是 研究建议确定HERG基因在卵巢癌组织中的表达水平 并确定HERG是否与其他钾有关 人心室和心房肌细胞中的通道亚单位。具体的 目的如下：1)确定基因的相对表达水平 用核糖核酸酶保护人心室和心房的HERG基因和蛋白 和Western印迹分析；2)免疫沉淀人心房HERG 和脑室膜制剂，并确定任何共同组装 利用免疫印迹技术表达蛋白质；3)表达心肌细胞 从对生成的钾电流的表征和比较 对人的心脏和心房的IKR。分子的测定 功能性人心房和心室IKR的组成将使 建立稳定表达这些IKR通道的细胞系。这些遗嘱 有助于详细研究通道生物物理、生物合成、 装配和翻译后处理，重要的是用于测试 针对IKR通道的治疗剂。

HERG has been identified as the locus of one form of long QT syndrome, LQT2, which can result in cardiac arrhythmias often leading to sudden death. Heterologous expression of HERG results in potassium currents very similar (but not identical) to the endogenous potassium current IKr which contributes to repolarization in the human heart. The goal of this research proposal is to determine the expression levels of HERG in the human heart and to determine if HERG is associated with other potassium channels subunits in human ventricular and atrial myocytes. The specific aims are as follows: 1) to determine the relative expression levels of HERG mRNA and protein human ventricles and atria using RNase protection and Western blot analyses; 2) to immunoprecipitate HERG from human atrial and ventricular membrane preparations and to identify any coassembling proteins using immunoblots; and 3) to express ventricular cardiac myocytes from characterization for the resultant potassium currents and comparison to human ventricular and atrial IKr. Determination of the molecular composition of functional human atrial and ventricular IKr will enable the production of stable cell lines expressing these IKr channels. These will be useful for detailed studies of channel biophysics, biosynthesis, assembly and post translational processing and, importantly, for testing therapeutic agents targeted against IKr channels.