Regulation of the actin filament pointed end dynamics in health and disease

健康和疾病中肌动蛋白丝尖端动态的调节

• 批准号: 9310099
• 负责人: Carol C Gregorio
• 金额: $ 40.98万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9310099
• 关键词: Actins; Affect; Architecture; Arizona; Binding; Binding Proteins; Binding Sites; Biological Assay; Biophysics; Cardiac; Cardiac Myocytes; Cardiomyopathies; Cells; Cellular biology; Circular Dichroism; Complex; Consensus; Contractile Proteins; Data; Development; Developmental Biology; Diagnostic; Disease; Equilibrium; F-Actin; Family; Family member; Genetic; Goals; Health; Heart; In Vitro; Individual; Induced Mutation; Interdisciplinary Study; Investigation; Knockout Mice; Laboratories; Length; Light; Link; Literature; Maintenance; Microfilaments; Microscopy; Minus End of the Actin Filament; Modeling; Molecular; Molecular Biology; Muscle; Muscle Cells; Muscle Contraction; Muscle Fibers; Muscle function; Mutate; Mutation; Myofibrils; Myopathy; Nemaline Myopathies; Nuclear Magnetic Resonance; Pathogenesis; Physiological; Physiology; Positioning Attribute; Property; Protein Isoforms; Proteins; Public Health; Publishing; Regulation; Research; Resolution; Role; Sarcomeres; Skeletal Muscle; Striated Muscles; Structural Biochemistry; Structure; Testing; Thin Filament; Tropomyosin; Universities; Washington; base; biophysical properties; cell type; design; experimental study; genetic regulatory protein; human disease; improved; in vivo; member; monomer; mouse model; muscular structure; mutant; new therapeutic target; polymerization; prevent; protein complex; protein structure; structural biology; three dimensional structure; tropomodulin

Alterations in the thin filaments involved in cardiac/skeletal muscle contraction often produce cardiomyopathies/nemaline myopathies with fatal consequences. Our long-term goal is to identify the components and molecular mechanisms regulating actin architecture in muscle during normal development and disease. Our short-term goal is to determine the mechanisms of how thin filament lengths are regulated by the actin filament pointed end binding proteins, leiomodin (Lmod) and tropomoduin (Tmod). Polymerization at the pointed end determines thin filament length and is regulated directly by the binding of tropomodulin (Tmod) and leiomodin (Lmod). This binding is enhanced by the integral thin filament component, tropomyosin (Tpm). We hypothesize that maintenance of thin filament length requires the antagonistic action of Tmod and Lmod; that is, the role of Tmod is to prevent elongation at the pointed end while Lmod allows elongation. We also predict that Tmod and Lmod binding and action at the pointed end is determined by different arrangements of their Tpm- and actin-binding sites. To achieve our goals, a powerful, multidisciplinary collaboration has been established between the Kostyukova laboratory at Washington State University (with expertise in protein structure, structural biochemistry and biophysical properties of actin filaments and regulatory proteins) and the Gregorio laboratory at the University of Arizona (with expertise in the molecular, cellular and developmental biology of myofibril assembly). In this proposal we will combine a broad range of state-of-the-art approaches such as determination of high-resolution atomic structure of Lmod /Tpm binding interface, and use of advanced microscopy and physiological assessment of myocytes from Lmod2 or Lmod3 null mice to test our molecular designs. The proposed experiments will connect Lmod-related thin filament alterations with familial myopathies. A better understanding of thin filament function and of its regulation is critical to better understand muscle disease pathogenesis, to improve diagnostics and to potentially identify novel drug targets.

参与心肌/骨骼肌收缩的细丝的改变通常会产生 具有致命后果的心肌病/线虫性肌病。我们的长期目标是确定 在正常发育过程中调节肌肉肌动蛋白结构的组分和分子机制 和疾病我们的短期目标是确定细纤维长度是如何被调节的机制， 肌动蛋白丝尖端结合蛋白，leiomodin（Lmod）和tropomoduin（Tmod）。聚合反应 尖端决定细丝长度，并直接受原调节蛋白（Tmod）的结合调节 和leiomodin（Lmod）。这种结合通过完整的细丝组分原肌球蛋白（Tpm）增强。 我们推测，细丝长度的维持需要Tmod和Lmod的拮抗作用; 也就是说，Tmod的作用是防止尖端处的伸长，而Lmod允许伸长。我们也 预测Tmod和Lmod在尖端的结合和作用是由不同的排列决定的， 它们的Tpm和肌动蛋白结合位点。为了实现我们的目标，一个强大的，多学科的合作已经 由华盛顿州立大学的Kostyukova实验室（具有蛋白质方面的专业知识） 肌动蛋白丝和调节蛋白的结构、结构生物化学和生物物理特性）和 亚利桑那大学Gregorio实验室（具有分子、细胞和发育方面的专业知识） 肌原纤维组装生物学）。在本建议书中，我们将联合收割机与各种最先进的方法相结合 例如确定Lmod /Tpm结合界面高分辨率原子结构，以及使用高级 来自Lmod 2或Lmod 3缺失小鼠的肌细胞的显微镜和生理学评估，以测试我们的分子生物学特性。 的设计.拟议的实验将Lmod相关的细丝改变与家族性 肌病更好地理解细丝的功能及其调节对于更好地理解 肌肉疾病的发病机制，以改善诊断和潜在地确定新的药物靶点。