Alpha-catenin function in cardiomyocyte adhesion and cytoskeletal organization

α-连环蛋白在心肌细胞粘附和细胞骨架组织中的功能

• 批准号: 10470291
• 负责人: Adam Vincent Kwiatkowski
• 金额: $ 38.93万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10470291
• 关键词: Actin-Binding Protein; Actins; Adaptor Signaling Protein; Adherens Junction; Adhesions; Adhesives; Affect; Allosteric Regulation; Architecture; Binding; Biochemical; Biochemistry; Biological; Cadherins; Cardiac Myocytes; Cardiomyopathies; Cell Adhesion; Cell Communication; Cell-Cell Adhesion; Cells; Cellular biology; Collection; Complex; Coupling; Cues; Cytoskeletal Modeling; Cytoskeletal Proteins; Cytoskeleton; Data; Desmosomes; Development; Epithelial; Equilibrium; Extracellular Matrix; Foundations; Goals; Grant; Health; Heart; Heart Diseases; Homeostasis; Human; In Situ; Individual; Intercalated disc; Intermediate Filaments; Knowledge; Lead; Ligand Binding; Ligands; Link; Maintenance; Mechanics; Mediating; Membrane; Microfilaments; Molecular; Mutation; Myofibrils; Outcome; Output; Peripheral; Property; Proteins; Proteomics; Publishing; Research; Role; Series; Signal Transduction; System; Testis; Thermodynamics; Tissues; Vinculin; Work; alpha catenin; cardiogenesis; design; experimental study; heart function; insight; link protein; mechanical force; mechanical signal; operation; protein complex; reconstitution; recruit; response; tool; treatment strategy

Project Summary With every heartbeat, the junctional complexes that couple cardiomyocytes must transmit the mechanical forces of contraction while maintaining adhesive homeostasis. Cardiomyocytes are linked end-to-end by the intercalated disc (ICD), a specialized junction that coordinates cell signaling, electrical and mechanical operations. The ICD comprises adherens junctions (AJs) and desmosomes that connect the actin and intermediate filament cytoskeletons, respectively, of adjoining cells. ICD function requires multiple adhesion and cytoskeletal proteins and mutations in these proteins are linked to cardiomyopathies. However, relatively little is known about how adhesion complexes are regulated to establish and maintain heart tissue integrity. The core of the adherens junction is the cadherin-catenin complex, which is connected to the actin cytoskeleton through a-catenin. a-Catenin is a multifunctional, mechanoresponsive actin-binding protein that localizes to the cardiomyocyte ICD. However, a-catenin functions in cell-cell adhesion in cardiomyocytes are poorly understood. Our objective in this application is to determine how mechanical and molecular inputs are transduced through the two a-catenins expressed in the human heart – aE(Epithelial)-catenin and aT(Testes)- catenin – to regulate cardiomyocyte adhesion. Our rationale is that defining the individual and collective roles of a-catenin at cardiomyocyte AJs will provide fundamental insight into how cardiomyocyte AJs balance mechanical and signaling functions. We hypothesize that aE-catenin and aT-catenin form unique cadherin- catenin complexes in response to cellular cues to function as mechanical checkpoints for ICD assembly and cardiomyocyte organization. In this proposal, we seek to: 1) define the allosteric mechanisms that regulate a- catenin ligand binding at the cardiomyocyte AJ; 2) determine how ligand recruitment to a-catenin promotes AJ assembly and cytoskeletal attachment; and 3) identify how external mechanical cues regulate AJ organization. Knowledge to be gained through our studies include a detailed, mechanistic understanding of how a-catenin molecular properties are tuned for adhesion in cardiomyocytes; how unique molecular complexes are built along the cardiomyocyte AJ to establish and maintain adhesion; and how external mechanical cues feed into the cardiomyocyte AJ to drive organization. This comprehensive, multiscale analysis will develop new tools and acquire new knowledge about the molecular mechanisms of cell adhesion in cardiomyocytes. Understanding the fundamental mechanisms of cell adhesion in cardiomyocytes is necessary for determining how mutations in ICD proteins lead to heart disease and inform the development of new strategies for the treatment of cardiomyopathies.

项目摘要 每一个心跳，夫妇心肌细胞的连接络合物都必须传输机械 在保持粘合剂稳态的同时，收缩力。心肌细胞由 Intercalated Disc（ICD），一种专门的连接，可协调细胞信号，电气和机械 运营。 ICD包括连接肌动蛋白和 相邻细胞的中间细胞细胞骨架。 ICD功能需要多个广告 这些蛋白质中的细胞骨架蛋白和突变与心肌病有关。但是，相对 关于如何调节粘合剂复合物以建立和维持心脏组织完整性，知之甚少。 粘附连接的核心是钙粘蛋白 - 钙蛋白复合物，该复合物连接到肌动蛋白 通过A-catenin的细胞骨架。 A-catenin是一种多功能的机械呼吸肌动蛋白结合蛋白， 定位于心肌细胞ICD。但是，A-catenin在心肌细胞中细胞细胞粘附中的功能是 理解不佳。我们在此应用中的目标是确定机械和分子输入的方式 通过在人心脏中表达的两个A-catenins- AE（上皮） - 蛋白酶和（睾丸） - （睾丸） - Catenin - 调节心肌细胞粘合剂。我们的理由是定义个人和集体角色 心肌细胞AJS的A-catenin将提供有关心肌细胞AJS平衡的基本见解 机械和信号功能。我们假设Ae-catenin和at-Catenin形成独特的cadherin- Catenin复合物响应细胞提示，作为ICD组装机械检查点的功能 心肌细胞组织。在此提案中，我们寻求：1）定义调节A-的变构机制 catenin配体在心肌细胞AJ处结合； 2）确定配体募集到A-catenin如何促进AJ 组装和细胞骨架附着； 3）确定外部机械提示如何调节AJ组织。 通过我们的研究获得的知识包括对A-catenin的详细机械理解 分子特性用于心肌细胞中的广告；独特的分子络合物的建造方式 沿着心肌细胞AJ建立和维持粘附；以及外部机械线索如何进食 心肌细胞AJ驱动组织。这种全面的多尺度分析将开发新工具 并获得有关心肌细胞细胞粘附的分子机制的新知识。 了解心肌细胞中细胞粘附的基本机制对于确定是必要的 ICD蛋白中的突变如何导致心脏病并为发展新策略的发展 心肌病的治疗。