Allele-Specific Effects of Single Amino Acid Exchange in cTnT

cTnT 中单个氨基酸交换的等位基因特异性效应

基本信息

批准号：
7588844
负责人：
Jil C Tardiff
金额：
$ 41.94万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-04-01 至 2012-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7588844
关键词：
Actins Actomyosin Address Adrenergic Agents Adrenergic Antagonists Alleles Amino Acid Substitution Amino Acids Animal Model Animals Binding Biological Assay Biophysics Cardiac Cardiomyopathies Cardiovascular system Cell physiology Clinical Complex Computer Simulation Cost Measures Development Disease Dobutamine Evaluation Exhibits Familial Hypertrophic Cardiomyopathy Funding Genes Genotype Goals Grant Head Heart Heart Diseases Homeostasis In Vitro Individual Infusion procedures Isoproterenol Lead Link Malignant - descriptor Measures Mechanics Mediating Methodology Microfilaments Modeling Molecular Motion Mus Muscle Contraction Mutation Myosin ATPase Organ Pathogenesis Pattern Peptides Phenotype Phosphorylation Physiological Physiology Property Protein Dynamics Protein Isoforms Proteins Regulation Research Research Design Research Project Grants Resolution Sarcomeres Signal Pathway Structure Therapeutic Thin Filament Transgenic Model Tropomyosin Troponin Troponin T Work adapter protein adrenergic base cell motility clinical phenotype cost disease-causing mutation flexibility in vivo insight malignant phenotype model development molecular dynamics molecular phenotype mouse model mutant programs response sudden cardiac death tool

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of the research program outlined in this application is to establish the mechanisms that link structural mutations in thin filament proteins to the development of Familial Hypertrophic Cardiomyopathy (FHC). During the original granting period we established that independent disease mutations at Residue 92 of cTnT (R92Q, R92W and R92L) result in discrete, mutation-specific alterations in cTnT structure and protein dynamics, energetics and contractile reserve, -adrenergic responsiveness and myocellular Ca2+ homeostasis. Moreover, many of these downstream cellular processes exhibit mutation-specific temporal changes that determine the progression of the resultant cardiomyopathy. Independent amino acid substitutions at a single residue of cTnT are thus sufficient to cause disparate physiologic phenotypes, and these phenotypes are the eventual result of specific changes in biophysical properties of the cTnT molecule. We have now developed the molecular, computational, cellular and whole-heart based tools to directly address this hypothesis and they define an integrative approach to establishing and eventually modifying the mechanistic link between mutations in cTnT and the malignant clinical course of FHC. These proposed studies are designed to both further our understanding of the pathogenesis of FHC and to provide new insights into the fundamental physiology and biophysics of the thin filament. In order to complete this research program we will implement the following three Specific Aims: Aim 1: To identify, evaluate and functionally }rank} the effects of known TNT1 mutations on the flexibility and structure of the 70-170 peptide around the critical }hinge} residue 104. Aim 2: To determine whether reducing the cost of contraction rescues the mutation-specific energetic-mechanical phenotypes of R92Q, R92L and R92W cTnT mutant hearts. Aim 3: To determine the mechanism(s) underlying the observed alterations in -adrenergic responsiveness in the R92 cTnT mutant hearts at the myofilament level. The completion of the studies will extend our understanding of how mutations in cTnT are mechanistically linked to their complex, malignant phenotype at the level of protein dynamics, cost of contraction, and energy reserve and the crucial myofilament response to -adrenergic stimulation. Moreover, we believe that these studies will both establish a new computational-functional paradigm for the study of thin filament cardiomyopathies and further expand our understanding of myofilament activation at the level of the cardiac sarcomere. Familial Hypertrophic Cardiomyopathy is one of the most common causes of sudden cardiac death in young people and the form of the disease caused by mutations in the thin filament protein cardiac Troponin T comprises a particularly malignant subset. The goal of this research project is to develop a integrated approach that utilizes computational modeling, development of rigorous genotype-molecular phenotype correlations and eventual whole-heart studies in animal models. The end result will be a better understanding of how these individual mutations in sarcomere proteins lead to severe cardiac disease and eventually lead to genotype-specific therapeutics for this currently untreatable disorder.

描述（由申请人提供）：本申请中概述的研究计划的长期目标是建立将薄丝蛋白质中的结构突变与家族性肥厚性心肌病（FHC）联系起来的机制。在最初的授予期内，我们确定CTNT 92（R92Q，R92W和R92L）的独立疾病突变会导致CTNT结构和蛋白质动力学，能量储备， - 肾上腺素能反应性和心肌细胞CAC2+稳态的离散，突变特异性变化。此外，这些下游细胞过程中的许多表现出突变特异性的时间变化，这些变化决定了所得心肌病的进展。因此，在CTNT的单个残基处的独立氨基酸取代足以引起不同的生理表型，并且这些表型最终是CTNT分子生物物理特性的特定变化的结果。现在，我们已经开发了分子，计算，细胞和全心脏的工具，以直接解决这一假设，并定义了一种综合方法来建立并最终改变CTNT中的突变与FHC的恶性临床过程之间的机械联系。这些提出的研究旨在进一步了解FHC的发病机理，并为薄丝的基本生理学和生物物理学提供新的见解。 In order to complete this research program we will implement the following three Specific Aims: Aim 1: To identify, evaluate and functionally }rank} the effects of known TNT1 mutations on the flexibility and structure of the 70-170 peptide around the critical }hinge} residue 104. Aim 2: To determine whether reducing the cost of contraction rescues the mutation-specific energetic-mechanical phenotypes of R92Q, R92L and R92W CTNT突变心。目标3：确定在肌丝水平上R92 CTNT突变心脏中观察到的肾上腺素能反应性改变的基础机制。研究的完成将扩展我们对CTNT中的突变如何在机械上与它们在蛋白质动力学，收缩成本和能量储备以及对肾上腺素能刺激的关键肌无丝反应的水平上的复杂，恶性表型联系在一起的理解。此外，我们认为这些研究都将建立一个新的计算功能范式来研究薄细丝心肌病，并进一步扩展我们对心脏肌肌膜激活的理解。家族性肥厚性心肌病是年轻人突然心脏死亡的最常见原因之一，也是由薄丝蛋白心脏肌钙蛋白T中突变引起的疾病形式，包括特别恶性的子集。该研究项目的目的是开发一种利用计算建模，严格基因型 - 分子表型相关性的开发以及动物模型中最终全心研究的综合方法。最终结果将更好地理解肌动蛋白中的这些个体突变如何导致严重的心脏病，并最终导致这种目前无法治疗的疾病的基因型特异性疗法。