Adrenergic Regulation of HERG Protein

HERG 蛋白的肾上腺素调节

• 批准号: 6812144
• 负责人: THOMAS V MCDONALD
• 金额: $ 41.75万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6812144
• 关键词: A kinase anchoring protein; G protein; SDS polyacrylamide gel electrophoresis; adrenergic receptor; biological signal transduction; electrophysiology; gene expression; genetic regulation; green fluorescent proteins; heart function; immunocytochemistry; immunoprecipitation; laboratory mouse; laboratory rabbit; membrane channels; phosphorylation; protein kinase A; protein protein interaction; protein quantitation /detection; protein structure function; protein transport; receptor expression; second messengers; voltage /patch clamp; western blottings; yeast two hybrid system

DESCRIPTION (provided by applicant): Regulation of ion channel function plays a pivotal role in controlling heart rate and contractility via changes in cardiac myocyte excitability. Humoral mediators and receptors are involved in determining channel responses to changing cardiovascular demands. The dynamic beat-to-beat regulation of ion channels is precisely controlled by autonomic stimulation through complex interplay of second messengers, kinases, G-proteins, and protein-protein interactions. The rapidly activating delayed rectifier current (IKr) produced by the HERG gene is uniquely qualified for an integrative transduction of cellular/hormonal signals due to its unusual biophysical properties and the growing number of second-messenger and protein interactions ascribed to the channel. We have begun mapping alpha- and beta-adrenergic signaling pathways to modulation of HERG/IKr. Beta-adrenergic stimulation leads to a complex series of events that includes; direct binding of cAMP to HERG, interactions with AKAPs, PKA-mediated phosphorylation of the channel, and binding of 14-3-3 to HERG. Thus, an evolving picture of adrenergic regulation of HERG is emerging. It will be essential to understand the mechanisms by which acute and chronic stress adaptation leads to arrhythmia and sudden death in both acquired and hereditary cardiac disease. Accordingly, we propose to explore the effects and mechanisms of each of these interactions in a multidisciplinary approach combining protein biochemistry, immunochemistry, and patch clamp electrophysiology on heterologously expressed proteins and endogenous cardiac tissue. Specifically, we aim to: 1. Determine the significance of 14-3-3e and PKA regulation of HERG 2. Examine PKA targeting to HERG channels by AKAPs. 3. Examine PKA-mediated control of trafficking of HERG protein.

描述（由申请人提供）：离子通道功能的调节在通过心肌细胞兴奋性的变化控制心率和收缩性中起关键作用。体液介质和受体参与决定对变化的心血管需求的通道反应。离子通道的动态逐拍调节通过第二信使、激酶、G蛋白和蛋白质-蛋白质相互作用的复杂相互作用由自主刺激精确控制。由HERG基因产生的快速激活的延迟整流电流（IKr）由于其不寻常的生物物理性质和归因于该通道的越来越多的第二信使和蛋白质相互作用而唯一地有资格用于细胞/激素信号的整合转导。我们已经开始绘制α-和β-肾上腺素能信号通路对HERG/IKr的调节。β-肾上腺素能刺激导致一系列复杂的事件，包括：cAMP与HERG的直接结合、与AKAP的相互作用、PKA介导的通道磷酸化以及14-3-3与HERG的结合。因此，一个不断发展的图片肾上腺素能调节HERG正在出现。了解急性和慢性应激适应导致获得性和遗传性心脏病中心律失常和猝死的机制至关重要。因此，我们建议探索这些相互作用的影响和机制，在一个多学科的方法相结合的蛋白质生物化学，免疫化学和膜片钳电生理学对异源表达的蛋白质和内源性心脏组织。具体而言，我们的目标是：1。确定14-3-3e和PKA调节HERG 2的意义。通过AKAP检查PKA靶向HERG通道。3.检查PKA介导的HERG蛋白运输控制。