Ion channel regulation by macromolecular complexes

大分子复合物对离子通道的调节

基本信息

批准号：
7822261
负责人：
Steven O Marx
金额：
$ 1.45万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-06-01 至 2010-10-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7822261
关键词：
1,2-diacylglycerol Action Potentials Address Adrenergic Receptor Agonist Angiotensin II Animal Model Antibodies Arrhythmia Biochemical Biological Calcium Canis familiaris Cardiac Cardiac Myocytes Cardiomyopathies Cardiovascular Diseases Cell physiology Cells Complex Congestive Heart Failure Coupling Data Development Diglycerides Dihydropyridines Disease Endothelin Event Family Gene Expression Heart Heart Hypertrophy Heart failure Homeostasis Hormones Human Hypertension Hypertrophy In Vitro Ion Channel Knock-in Mouse Lead Macromolecular Complexes Maps Mediating Modeling Molecular Morphology Mus Neurotransmitters Nodal Pacemakers Pathway interactions Peptides Pharmaceutical Preparations Phase Phorbol Esters Phosphoric Monoester Hydrolases Phosphorylation Phosphorylation Site Phosphotransferases Physiology Play Property Protein Isoforms Protein Kinase Protein Kinase C Pump Rattus Reagent Regulation Relaxation Renin-Angiotensin System Research Personnel Role Sarcolemma Signal Pathway Signal Transduction Site Sympathetic Nervous System System Tachycardia Techniques Testing Therapeutic Agents Time Tissues Transfection Upper arm analog animal tissue base depressed design dihydropyridine insight mutant novel novel therapeutics pressure programs research study response translational study voltage

项目摘要

DESCRIPTION (provided by applicant): Modulation of ion channels by macromolecular signaling complexes and phosphorylation plays an important role in the regulation of excitation-contraction (E-C) coupling. In cardiac myocytes, the L-type Ca2+ channel (Cav1.2) current (ICa), the major depolarizing current contributing to the plateau of the action potential and E-C coupling, is highly regulated by hormones, in large part through the activation of protein kinases and phosphatases. It is well established that Cav1.2 plays a key role in modulating cardiac function in response to classical signaling pathways, such as the renin-angiotensin system (RAS) and sympathetic nervous system (SNS). Treatment of several major cardiovascular diseases is dependent, in part, upon the modulation of these pathways by drugs. This proposal focuses on gaining a better understanding of the mechanisms by which a major cardiac protein kinase, protein kinase C (PKC), which is activated by the RAS and SNS, modulates the function of Cav1.2. We have mapped critical PKC phosphorylation sites on the Cav1.2 alpha1c and beta2 subunits and have prepared phospho-peptide specific antibodies; each uniquely designed to recognize only a single phosphorylated Cav1.2 channel site. Our preliminary data suggest that the different cardiac PKC isoforms can phosphorylate distinct Cav1.2 sites in vitro. Utilizing the phospho-peptide and site specific antibodies, the applicant proposes to study the role of different PKC isoforms in the modulation of Cav1.2 in normal and pathological hearts. Three specific aims are proposed: (1) To characterize biochemically and pharmacologically the phosphorylation of Cav1.2 in cells, tissues and animals; (2) To characterize electrophysiologically PKC modulation of cardiac Cav1.2; (3) To characterize the PKC modulation of Cav1.2 in heart failure and hypertrophy. Utilizing biochemical, molecular biological, and electrophysiological techniques, we will explore the molecular mechanisms and cellular signaling pathways impinging upon Cav1.2 regulation in normal and diseased hearts. Electrophysiological characterization of the effects of PKC phosphorylation of specific Cav1.2 residues will be carried out in heterologous expression systems and cardiomyocytes. Since heart failure and hypertrophy are associated with alterations in PKC activity and Ca2+ homeostasis, understanding the PKC modulation of Cav1.2 may contribute to the development of novel therapeutic agents to treat these disorders.

描述（由申请人提供）：通过大分子信号传导复合物和磷酸化对离子通道的调节在调节激发诱导（E-C）耦合中起重要作用。在心肌细胞中，L型Ca2+通道（CAV1.2）电流（ICA），这是对动作电位和E-C偶联高原的主要去极化电流，由激素高度调节，这在很大程度上是通过蛋白激酶和磷酸酶的激活而大部分。众所周知，CAV1.2在响应经典信号通路（例如肾素 - 血管紧张素系统（RAS）和交感神经系统（SNS））中调节心脏功能方面起着关键作用。几种主要的心血管疾病的治疗部分取决于药物对这些途径的调节。该建议着重于更好地了解主要心脏蛋白激酶蛋白激酶C（PKC）的机制，该机制被RAS和SNS激活，调节CAV1.2的功能。我们已经绘制了CAV1.2α1c和beta2亚基上的临界PKC磷酸化位点，并制备了磷酸肽特异性抗体。每个唯一设计的旨在仅识别单个磷酸化的CAV1.2通道位点。我们的初步数据表明，不同的心PKC同工型可以在体外磷酸化不同的CAV1.2位点。利用磷酸肽和特定于位点的抗体，申请人提议研究不同PKC同工型在正常和病理心脏中CAV1.2调节中的作用。提出了三个具体目的：（1）在细胞，组织和动物中在生化和药理学上表征Cav1.2的磷酸化；（2）表征心脏CAV1.2的电生理学调节；（3）表征心力衰竭和肥大中CAV1.2的PKC调节。利用生化，分子生物学和电生理技术，我们将探索撞击正常心脏和患病心脏调节CAV1.2调节的分子机制和细胞信号通路。特异性CAV1.2残基的PKC磷酸化作用的电生理表征将在异源表达系统和心肌细胞中进行。由于心力衰竭和肥大与PKC活性和Ca2+稳态的改变有关，因此了解CAV1.2的PKC调节可能有助于发展新型治疗剂以治疗这些疾病。