ATP-SENSITIVE POTASSIUM CHANNELS IN THE HEART

在心脏中，代谢状态的主要传感器，因此是缺血的潜在主要参与者，是ATP敏感性钾（KATP）通道，其将代谢状态与电兴奋性联系起来。该项目旨在了解心脏KATP通道代谢控制的分子基础，以及这些通道在缺血反应中的病理生理作用。以前已经表明，磺酰脲受体（SUR）亚型，特别是核苷酸结合折叠（NBFs）是组织特异性KATP功能的关键决定因素。它还表明，SUR 1和SUR 2A差异调节KATP通道，SUR 1在生理条件下产生更活跃的通道。开发了在心脏中过表达KATP通道亚基的新型转基因小鼠，包括过表达SUR 1和SUR 2A的小鼠。SUR 1的过度表达仅引起猝死。为了扩展这些初步的数据实验提出解决以下问题：（1）NBF-核苷酸相互作用如何调节KATP通道？为了实现这一目标，已经开发了一系列新的工具，包括SUR 1的荧光报告构建体和一种新的特异性抗SUR 1抗体。这些将用于一系列旨在解决该问题的生化和重组蛋白水平方法的实验。所提出的实验的结果将带来详细的洞察KATP通道功能的结构和机制的基础上，心脏功能的差异SUR异构体的作用。

In the heart, a major sensor of the metabolic state, and hence a potentially major player in ischemia, is the ATP-sensitive potassium (KATP) channel, which links metabolic state to electrical excitability. This project seeks to understand the molecular basis for metabolic control of KATP channels in the heart, and the pathophysiological role of these channels in the response to ischemia. Previously it has been shown that sulfonylurea receptor (SUR) isoforms, and in particular the nucleotide binding folds (NBFs) are critical determinants of tissue-specific KATP function. It has also been shown that SUR1 and SUR2A differentially regulate KATP channels, with SUR1 generating more active channels under physiological conditions. Novel transgenic mice overexpressing KATP channels subunits in the heart were developed, including mice overexpressing SUR1 and SUR2A. Overexpression of SUR1 only caused sudden death. In order to extend these preliminary data experiments are proposed to address the following question: (1) How do NBF-nucleotide interactions regulate KATP channels? In order to achieve this aim, a series of novel tools have been developed, including fluorescent reporter constructs of SUR1 and a novel specific anti-SUR1 antibody. These will be used in a series of experiments aimed at a biochemical and recombinant protein level approach to the problem. The results of the proposed experiments will bring detailed insight to the structural and mechanistic basis of KATP channel function and the role of differential SUR isoforms in cardiac function.