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：使能技术和特定的挑战主题神经科学突破技术（06-NS-103）。该提案的标题是“离子通道跨膜辅助亚基的全基因组筛选”。器官中的离子稳态（例如，脑、心脏、肾脏、胃肠道等）在人类中起着重要作用，其失调会导致致命或严重的疾病。离子稳态由离子调节剂控制，离子调节剂包括离子通道、转运蛋白和泵。由于这些蛋白质可能代表治疗疾病和病症的药物靶标，因此已经使用基因组方法进行了大量工作，以通过使用活性或同源性搜索的表达克隆在分子水平上鉴定离子调节剂的成孔或催化亚基。在异源细胞中过表达的克隆的成孔通道亚基表现出通道活性。然而，对于许多通道，已经报道了重组和天然通道之间观察到的通道特性的差异，这通过最近鉴定辅助亚基来解释（杰克逊和Nicoll，2009; Tigaret和Choquet，2009）。辅助亚基的存在使离子调节剂的研究严重复杂化，因为具有辅助亚基的离子调节剂的性质和药理学不同。此外，新的辅助亚基的鉴定负担的研究人员与繁琐和耗时的任务，通过表达孔形成或催化亚基单独在异源细胞中的离子调节剂的特征。为了克服这一局限性，在离子调节剂的研究，我们想提出一个系统的和全基因组的筛选方法，以确定跨膜调节剂/辅助亚基的离子通道。由于人类基因组编码超过1，500种离子调节剂，我们相信所提出的筛选方法的成功开发将影响与各种器官系统和由离子稳态失调引起的疾病有关的广泛研究领域。此外，这种识别通道辅助亚基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会导致人类疾病，称为通道病，我们可以确定这些疾病的新药物靶点。此外，通道病不仅影响大脑，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剂有关的广泛研究领域。 公共卫生相关性：在这里，我们提出了一个简单的，但新颖的，方法来确定新的通道亚基系统地使用全基因组筛选方法。由于许多离子通道的改变会导致人类疾病，称为通道病，我们可以确定这些疾病的新药物靶点。此外，通道病不仅影响大脑，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.