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.

心脏/骨骼肌收缩涉及的细丝的改变通常会产生 心肌病/肾上腺素肌病和致命后果。我们的长期目标是确定 正常发育过程中调节肌肉肌动蛋白结构的组成部分和分子机制 和疾病。我们的短期目标是确定细丝长度如何受到的机制。 肌动蛋白丝指向末端结合蛋白，Leiomodin（LMOD）和Tropomoduin（TMOD）。聚合在 尖端确定细丝长度，并通过托托瘤蛋白（TMOD）的结合直接调节 和Leiomodin（LMOD）。积分细丝组件Tropomyosin（TPM）增强了这种结合。 我们假设维持薄丝长度需要TMOD和LMOD的拮抗作用。 也就是说，TMOD的作用是防止在尖端端伸长，而LMOD允许伸长。我们也是 预测尖端端的TMOD和LMOD结合和动作由不同的安排决定 他们的TPM和肌动蛋白结合位置。为了实现我们的目标，有力的多学科合作已经 在华盛顿州立大学的Kostyukova实验室之间建立（具有蛋白质专业知识 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 亚利桑那大学的Gregorio实验室（具有分子，细胞和发育方面的专业知识 肌原纤维组件的生物学）。在此提案中，我们将结合广泛的最新方法 例如确定LMOD /TPM结合界面的高分辨率原子结构，并使用高级 LMOD2或LMOD3无效小鼠的肌细胞的显微镜和生理评估以测试我们的分子 设计。提出的实验将将与LMOD相关的细丝改变与家族性联系起来 肌病。更好地了解细丝功能及其法规对于更好地理解至关重要 肌肉疾病的发病机理，改善诊断和潜在地识别新的药物靶标。