Genome wide screening of transmembrane accessory subunits of ion channels

描述(由申请人提供)：本申请涉及广泛的挑战领域06：使能技术和特定挑战主题神经科学的突破技术(06-NS-103)。这项建议的标题是“跨膜离子通道辅助亚基的全基因组筛选”。器官(如脑、心脏、肾脏、胃肠道等)的离子动态平衡在人类中起着至关重要的作用，其失调会导致致命性或严重的疾病。离子动态平衡是由离子调节器控制的，离子调节器包括离子通道、转运体和泵。由于这些蛋白质可能代表治疗疾病和紊乱的药物靶点，人们已经开展了广泛的工作，利用基因组学方法，通过使用活性或同源性搜索进行表达克隆，在分子水平上鉴定离子调节蛋白的孔道形成或催化亚基。在异源细胞中过度表达的克隆的造孔通道亚基具有通道活性。然而，已有报道在许多通道中观察到重组通道和天然通道之间的通道特性差异，这可以通过最近确定的附属亚基来解释(Jackson和Nicoll，2009；Tigaret和Choket，2009)。辅助亚单位的存在使离子调节剂的研究变得非常复杂，因为辅助亚单位与离子调节剂的性质和药理作用不同。此外，识别新的辅助亚基给研究人员带来了繁琐和耗时的任务，即通过在异源细胞中单独表达造孔或催化亚基来表征离子调节因子。为了克服离子调节剂研究中的这一局限，我们提出了一种系统的、全基因组的筛选方法来鉴定离子通道的跨膜调节剂/附属亚基。由于人类基因组编码1,500多种离子调节因子，我们相信，拟议中的筛选方法的成功开发将影响与各种器官系统和离子稳态失调引起的疾病相关的广泛研究领域。此外，这种识别通道辅助亚单位的创新方法为理解离子通道的功能和调节提供了新的工具。由于许多离子通道的改变导致人类疾病，这被称为通道病，我们可能会为这些疾病确定新的药物靶点。此外，经络病不仅影响大脑，还影响其他组织，包括肾脏、肌肉和心脏。因此，这种方法的建立将影响和刺激与离子调节器有关的广泛领域的研究。 公共卫生相关性：我们在这里提出了一种简单但新颖的方法，利用全基因组筛查方法系统地识别新的通道亚基。由于许多离子通道的改变导致人类疾病，这被称为通道病，我们可能会为这些疾病确定新的药物靶点。此外，经络病不仅影响大脑，还影响其他组织，包括肾脏、肌肉和心脏。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area 06: Enabling technologies and specific Challenge Topic Breakthrough technologies for neuroscience (06-NS-103). The title of this proposal is "Genomewide screening of transmembrane accessory subunits of ion channels". Ion homeostasis in organs (e.g., brain, heart, kidney, gastrointestinal tract, etc.) plays critical roles in human and its dysregulation causes lethality or serious disorders. Ion homeostasis is controlled by ion regulators, which include ion channels, transporters, and pumps. Because these proteins may represent drug targets to treat disease and disorders, extensive work has been carried out using genomic approaches to identify pore-forming or catalytic subunits of ion regulators at the molecular level via expression cloning using activity or homology searches. Cloned pore-forming channel subunits overexpressed in heterologous cells exhibit channel activity. However, differences in channel properties observed between recombinant and native channels have been reported for many channels, which were explained by the identification of accessory subunits recently (Jackson and Nicoll, 2009; Tigaret and Choquet, 2009). The existence of accessory subunits severely complicates the study of ion regulators, as the properties and pharmacology of ion regulators with accessory subunits are different. Furthermore, identification of novel accessory subunits burdens researchers with the cumbersome and time-consuming task of characterizing ion regulators by expressing pore-forming or catalytic subunits alone in heterologous cells. To overcome this limitation in the study of ion regulators, we would like to propose a systematic and genome wide screening method to identify transmembrane regulators/accessory subunits of ion channels. Because the human genome encodes more than 1,500 ion regulators, we believe that the successful development of the proposed screening method will impact a broad field of research pertaining to various organ systems and diseases caused by the dysregulation of ion homeostasis. Furthermore, this innovative approach to identify channel accessory subunits provides a new tool to understand the functioning and regulation of ion channels. Because alterations in many ion channels cause human disorders, which are termed channelopathies, we may identify new drug targets for these diseases. Furthermore, channelopathies affect not only the brain but also other tissues, which include the kidney, muscle, and heart. Therefore, the establishment of this approach will impact and stimulate a broad area of research pertaining to ion regulators. PUBLIC HEALTH RELEVANCE: We here propose a simple, but novel, approach to identify novel channel subunits systematically using a genome-wide screening approach. Because alterations in many ion channels cause human disorders, which are termed channelopathies, we may identify new drug targets for these diseases. Furthermore, channelopathies affect not only the brain but also other tissues, which include the kidney, muscle, and heart.