Proteolytic Regulation of Troponin T & Cardiac Function

肌钙蛋白 T 的蛋白水解调节

基本信息

批准号：
8520384
负责人：
Jian-Ping Jin
金额：
$ 49.42万
依托单位：
WAYNE STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-01 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8520384
关键词：
ATP phosphohydrolase Actomyosin Adenosinetriphosphatase Acute Affect Alternative Splicing Animals Binding Binding Sites Biochemical Biochemistry C-terminal Calcium Calmodulin Calpain Cardiac Cardiac Muscle Contraction Cardiac Myocytes Cessation of life Chronic Complex Congestive Heart Failure Development Dose Excision Exercise Family Financial compensation Foundations Functional disorder Future Genes Heart Heart failure Immunoglobulin Variable Region Infarction Injury Ischemia Knowledge Lead Life Link Mechanics Microfilaments Modeling Modification Molecular Conformation Motor Mus Muscle Muscle Cells Myocardial Myocardial Contraction Myocardial Ischemia Myocardial dysfunction Myocardium Myofibrils Myosin ATPase Myosin Light Chains N-terminal Nature Phase Phenotype Physiologic intraventricular pressure Physiological Plant Roots Post-Translational Protein Processing Post-Translational Regulation Preparation Prevention approach Production Protein Binding Protein Subunits Proteolysis Pump Rattus Regulation Regulation of Proteolysis Reperfusion Injury Reperfusion Therapy Reporting Research Project Grants Role Skin Stress Stretching Striated Muscles Structure Structure-Activity Relationship System Testing Thin Filament Time Transgenic Mice Transgenic Organisms Translating Tropomyosin Troponin Troponin C Troponin I Troponin T Variant Ventricular Work base cardiogenesis clinical application connectin coping functional loss genetic regulatory protein heart function improved in vivo novel postnatal pressure protein complex public health relevance receptor reconstitution research study response therapeutic development

项目摘要

DESCRIPTION (provided by applicant): Cardiac muscle contraction is regulated by Ca2+ through the troponin complex that consists of three protein subunits: troponin C, troponin I, and troponin T (TnT). This research project investigates the role of a novel posttranslational modification of cardiac TnT (cTnT) in myocardial adaptation to energetic crisis. We recently reported a restricted N-terminal proteolysis of cTnT in myocardial ischemia-reperfusion (Zhang et al., Biochemistry 45:11681-94, 2006) and pressure overload (Feng et al., J. Physiol. 586:3537-50, 2008). This modification selectively removes the N-terminal variable region of cTnT but keeps the conserved middle and C-terminal regions intact. Initial studies in transgenic mouse hearts showed that the N-terminal truncated cTnT (cTnT-ND) remains functional in the myofilaments and alters myocardial contractility. This finding has lead to a hypothesis that the proteolytic removal of the N-terminal variable region of cTnT produces a functional state in cardiac muscle thin filaments as acute adaptation to energetic crisis. To test this hypothesis and understand the physiological and pathophysiological significance of cTnT- ND, three Specific Aims are proposed in this research project: Aim I will characterize the effects of the selective deletion of the N-terminal variable region on the function of cTnT. We will examine the interactions of cTnT-ND with other thin filament regulatory proteins and its functional impacts on the Ca2+ activation of myofibril ATPase and the contractility of cardiac muscle. Aim II will study the role of N-terminal truncated cTnT in compensating cardiac function and providing myocardial protection against ischemia-reperfusion injury. The acute and chronic effects of cTnT-ND on heart function and its role in overcoming energetic crisis will be investigated in ex vivo working hearts and in vivo. Aim III will investigate the role of mechanical stretch of the cardiac muscle in inducing the restricted proteolytic cleavage of cTnT N-terminal segment in order to understand the mechanisms that regulates this posttranslational regulation. Using integrated experimental systems, this study will gain new knowledge for the structure-function relationships of TnT and lay a foundation for future development of new treatment of ischemic heart disease and heart failure.

描述（由申请人提供）：心肌收缩由Ca2+通过肌钙蛋白复合物调节，由三种蛋白质亚基组成：肌钙蛋白C，肌钙蛋白I和肌钙蛋白T（TNT）。该研究项目研究了心肌TNT（CTNT）在心肌适应充满活力危机中的新型翻译后修饰的作用。我们最近报道了CTNT在心肌缺血 - 重新灌注中的N端蛋白水解受限（Zhang等，生物化学45：11681-94，2006）和压力超负荷（Feng等人，J。Physiol。586：3537-50-50，586：3537-50，，， 2008）。这种修饰选择性地去除了CTNT的N末端变量区域，但保持保守的中间和C末端区域完整。在转基因小鼠心脏中的初步研究表明，N末端截短的CTNT（CTNT-ND）在肌膜中保持功能，并改变心肌收缩力。这一发现导致了一个假设，即CTNT的N末端变量区域的蛋白水解去除会在心脏肌肉薄细丝中产生功能状态，因为急性适应能量危机。为了检验这一假设并了解CTNT的生理和病理生理学意义，在本研究项目中提出了三个具体目的：目的我将表征N端变量区域选择性缺失对CTNT功能的影响。我们将检查CTNT-ND与其他薄丝调节蛋白的相互作用及其对肌纤维ATPase Ca2+激活的功能影响和心脏肌肉的收缩力。 AIM II将研究N末端截断CTNT在补偿心脏功能方面的作用，并提供针对缺血再灌注损伤的心肌保护。 CTNT-ND对心脏功能的急性和慢性作用将在离体工作心脏和体内研究。 AIM III将研究心肌的机械拉伸在诱导CTNT N末端段的蛋白水解裂解中的作用，以了解调节这种翻译后调节的机制。使用综合实验系统，本研究将获得TNT结构功能关系的新知识，并为未来的缺血性心脏病和心力衰竭的新治疗奠定了基础。