Role of Kir6.1 subunits of K+ channels in heart

K 通道 Kir6.1 亚基在心脏中的作用

• 批准号: 6530737
• 负责人: William A Coetzee
• 金额: $ 41.25万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6530737
• 关键词: adenosine triphosphate; bioenergetics; blood flow measurement; cardiac myocytes; cytoprotection; genetically modified animals; heart circulation; heart metabolism; isolation perfusion; laboratory mouse; myocardial ischemia /hypoxia; potassium channel; protein structure function; voltage /patch clamp

DESCRIPTION (the applicant's description verbatim): ATP-sensitive (KATP) channels couple energy metabolism and stress to membrane excitability and are highly expressed in heart. Their function in the heart and coronary vasculature has been studied extensively by the use of pharmacological agents that open or block KATP channels. The molecular cloning of subunits of KATP channel revealed that KATP channels consist of pore-forming Kir6 subunits in association with regulatory SUR subunits. There are two Kir6 members (Kir6.1 and Kir6.2) - both are highly expressed in heart. Cardiac KATP channels are believed to consist of Kir6.2/SUR2 complexes. However, the role of Kir6.1 is unknown. The overall goal of this application is to examine the function of Kir6.1 subunits in the cardiovascular system. Since the localization of a protein can be indicative of its function, we will examine the regional, cellular and subcellular distribution patterns of Kir6.1 subunits in cardiac myocytes, the conduction system, in the coronary vasculature and in endothelial cells using immunohistochemistry techniques (we have developed excellent antibodies for this purpose). We show biochemically and electrophysiologically that Kir6.1 and Kir6.2 subunits can co-assemble in heterologous expression systems, suggesting that this may also occur in heart. We will examine whether such co-assembly takes place for native Kir6 proteins. We will also investigate the functional characteristics of heteromeric Kir6 channels using patch clamp techniques. We will generate mice with targeted disruption of the Kir6.1 gene. LoxP sites will be introduced in the Kir6.1 locus and these mice will be crossed with others overexpressing Cre in the heart. We will utilize these mice directly to examine the role of Kir6.1 subunits in the function of heart and vasculature using isolated, Langendorff-perfused heart techniques. Coronary blood flow and -reserve will be measured along with heart function during ischemia, reperfusion and ischemic preconditioning. These studies will provide a framework in which to understand the complexity of KATP channels in the cardiovascular system, in particular the role of Kir6.1 subunits, and will provide molecular insights into the function of KATP channels in animals during normal and pathophysiological conditions.

描述（申请人的描述逐字描述）：ATP敏感（KATP） 渠道将能量代谢和膜兴奋性的压力夫妇融合，并且是 高度表达内心。它们在心脏和冠状动脉血管中的功能 通过使用开放或 阻止KATP通道。 Katp通道亚基的分子克隆显示 KATP通道由形成孔的Kir6亚基与 监管SUR亚基。有两个Kir6成员（Kir6.1和Kir6.2） - 两者都 在内心高度表达。心脏KATP频道被认为包括 Kir6.2/sur2复合物。但是，Kir6.1的作用尚不清楚。总体目标 此应用程序是检查Kir6.1亚基的功能 心血管系统。由于蛋白质的定位可以指示 它的功能，我们将检查区域，细胞和亚细胞 心肌细胞中Kir6.1亚基的分布模式，传导 系统，在冠状动脉脉管系统和内皮细胞中使用 免疫组织化学技术（我们开发了出色的抗体 这个目的）。我们在生化和电生理上表明Kir6.1和 Kir6.2亚基可以在异源表达系统中共组装，这表明 这也可能发生在心中。我们将研究这种共同组装 用于天然KIR6蛋白。我们还将研究功能 使用斑块夹技术的异元KIR6通道的特征。我们 将产生靶向破坏Kir6.1基因的小鼠。 LOXP站点将 在Kir6.1基因座中引入，这些小鼠将与其他小鼠交叉 过表达的CRE在心脏中。我们将直接利用这些小鼠检查 Kir6.1亚基在心脏和脉管系统功能中的作用 孤立的，Langendorff的心脏技术。冠状动脉流动和 - 在缺血期间将与心脏功能一起测量， 再灌注和缺血性预处理。这些研究将提供 在其中了解KATP通道复杂性的框架 心血管系统，特别是Kir6.1亚基的作用，将 提供分子见解，以了解动物在动物中的功能 正常和病理生理状况。