Post-translational Modification in Cardiac Muscle

心肌翻译后修饰

• 批准号: 7939634
• 负责人: Brandon J Biesiadecki
• 金额: $ 24.9万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-25 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7939634
• 关键词: Affect; Affinity; Binding; Ca(2+)-Transporting ATPase; Calcium; Cardiac; Cardiac Myocytes; Data; Development; Disease; Fiber; Functional disorder; Goals; Heart Diseases; Heart failure; Human; Modification; Molecular; Myocardial Infarction; Myocardium; Phosphorylation; Post-Translational Protein Processing; Protein Binding; Proteins; Reperfusion Therapy; Role; Signal Transduction; Stress; Thin Filament; Transgenic Mice; Tropomyosin; base; heart function; improved; insight; mortality; nitration; novel; overexpression; reconstitution; therapy development

Tropomyosin (Tm) is modified by both posphorylation and nitration post-translational modifications. To date tiie functional significance of Tm pfiospliorylation and nitration are not well understood. It is the goal of this proposal to identify the effect of Tm phosphorylation and nitration on its interactions with the sarcomeric proteins and on activation of the sarcomeric thin filament. Recent data has suggested the post-transiational modification of Tm may be regulated, therefore we further propose to investigate the effect of cardiac stress on the level of Tm post-translational modifications as a novel signaling mechanism to alter cardiac sarcomeric contraction. This application contains three specific aims to investigate these questions. 1) Does cardiac stress alter the post-tranlational modification of Tm to affect contractile function? 2) Does the posttranslational modification of Tm by phsophorylation or nitration alter its interactions within the thin filament protein network? 3) Do post-transiational modifications of Tm alter Ca2+ activation of the thin filament? These aims wiil be carried out by investigating the effect of Tm that has been modified by either phosphorylation or nitration on Tm binding affinity to the other sarcomeric thin filament proteins, the binding of Ca2+ and the ATPase activity of reconstituted thin filaments. We also propose to investigate the effect of cardiac stress on Tm post-translational modifications by treating cardiac myocytes with ischemic reperfusion followed by identification of Tm phosphorylation and nitration levels. We will investigate the significance of Tm phosphorylation by investigating calcium regulated force development in cardiac fibers from transgenic mice overexpressing pseudo-phosphorylated Tm. These studies will provide a much needed molecular understanding of how the post-translaitonal modification of Tm functions to affect cardiac contraction at the sarcomeric level and its role as a novel signaling mechanism to affect cardiac contraction in ischemic reperfusion. The findings from these studies are direclty relevant to understanding the molecular basis of cardiac dysfunction in human myocardial infarction. These studies wiil also provide new insight into potential pharmacotheriputic treatments to improve heart function in both myocardial infarction and disease.

原肌球蛋白 (Tm) 通过磷酸化和硝化翻译后修饰进行修饰。迄今为止，Tm 磷酸化和硝化的功能意义尚不清楚。本提案的目标是确定 Tm 磷酸化和硝化对其与肌节蛋白相互作用以及肌节细丝激活的影响。最近的数据表明 Tm 翻译后修饰可能受到调节，因此我们进一步建议研究心脏应激对 Tm 翻译后修饰水平的影响，作为改变心脏肌节收缩的新信号机制。该应用程序包含三个具体目标来调查这些问题。 1) 心脏应激是否会改变 Tm 的翻译后修饰从而影响收缩功能？ 2）通过磷酸化或硝化对Tm进行翻译后修饰是否会改变其在细丝蛋白网络内的相互作用？ 3) Tm 的翻译后修饰是否会改变细丝的 Ca2+ 激活？ 这些目标将通过研究 Tm 的影响来实现，Tm 已被以下任一方法修改： 磷酸化或硝化对 Tm 与其他肌节细丝蛋白的结合亲和力、Ca2+ 的结合以及重建细丝的 ATP 酶活性的影响。我们还建议通过缺血再灌注处理心肌细胞，然后鉴定 Tm 磷酸化和硝化水平，研究心脏应激对 Tm 翻译后修饰的影响。我们将通过研究过度表达假磷酸化 Tm 的转基因小鼠心肌纤维中钙调节力的发展来研究 Tm 磷酸化的重要性。这些研究将为 Tm 平移后修饰如何在肌节水平影响心脏收缩及其作为影响缺血再灌注中心脏收缩的新型信号机制的作用提供急需的分子理解。这些研究的结果与了解人类心肌梗死心脏功能障碍的分子基础直接相关。这些研究还将为改善心肌梗塞和疾病的心脏功能的潜在药物治疗提供新的见解。