The UNC-45 Chaperone as a Modulator of Myosin Biogenesis and Function

UNC-45 伴侣作为肌球蛋白生物发生和功能的调节剂

基本信息

批准号：
9267166
负责人：
GUY Martin BENIAN
金额：
$ 30.69万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-05-01 至 2020-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9267166
关键词：
Address Amino Acids Animals Binding Biochemical Biogenesis Biological Biological Assay Biological Models Biology Biophysics CRISPR/Cas technology Caenorhabditis elegans Cardiomyopathies Cell division Clustered Regularly Interspaced Short Palindromic Repeats Collaborations Data Development Drosophila genus Equilibrium Exposure to Functional disorder Genes Head Heat Stress Disorders Heat-Shock Proteins 90 Heat-Shock Response Hydrogen Peroxide In Vitro Investigation Knowledge Lead Length Mediating Microfilaments Molecular Molecular Chaperones Molecular Conformation Motor Muscle Muscle Cells Muscle Development Muscle function Mutagenesis Mutation Myofibrils Myopathy Myosin ATPase Myosin Type II Phenotype Physiological Process Protein Isoforms Proteins Publishing Recovery Recruitment Activity Regulation Research Research Personnel Role Sarcomeres Series Site Skeletal Muscle Stress Striated Muscles Structure System Techniques Testing Thick Filament Up-Regulation Vertebrates Work cell motility cell type crystallinity developmental disease experimental study human disease in vivo inhibitor/antagonist insight member multidisciplinary mutant non-muscle myosin novel novel therapeutic intervention novel therapeutics premature prevent protein complex protein folding public health relevance repaired response skeletal stem temperature sensitive mutant tumor tumor progression

项目摘要

DESCRIPTION (provided by applicant): In this proposal we aim to elucidate the precise molecular mechanisms by which the chaperones UNC-45 and Hsp90 assist in the folding of the myosin head which is critical for sarcomere assembly during development and repair of stress-induced damage to sarcomeres in mature muscle. Developing an understanding of these mechanisms is a problem at the core of muscle development and function. It is also highly relevant to the folding and repair of the many classes of myosin molecules that are expressed in non-muscle tissues. Our recent discovery that myosin attains a novel conformation, which hydrolyzes ATP at the normal rate but with a greatly reduced ability to translocate actin filaments, in the presence of UNC-45 and is reversed by Hsp90, raises important questions as to the exact roles of these chaperones in myosin folding and repair and myofilament assembly. Guided by our recent published and preliminary studies, we hypothesize that during myosin assembly or repair, UNC-45 assists the myosin head to attain its native conformation and subsequently locks it in a state that prevents premature powerstrokes; this state is relieved by Hsp90 upon successful assembly into the sarcomere or repair of myosin heads. This hypothesis will be tested by using a combination of in vitro and in vivo analyses through a unique collaboration between two expert research labs. In Aim 1 we will use mutagenesis, biochemical and biophysical assays, including myosin-dependent actin filament gliding assays, to establish the UNC-45 domains and key amino acid regions that mediate the different unique functions of UNC-45. In Aims 2 and 3 we will use the power of C. elegans as a model system to examine the functional relationships between mutant UNC-45 proteins and sarcomere assembly (Aim 2), and the dynamics of association of UNC-45 and Hsp90 with themselves and with myosin during repair of damaged myosin heads (Aim 3). Our hypothesis, if confirmed, will represent a new paradigm in the biology of myosins, with potential novel therapeutic approaches not only for striated muscle disorders stemming from mutations in sarcomeric proteins (skeletal myopathies and cardiomyopathies), but also for the problem of tumor invasiveness.

描述（由申请人提供）：在本提案中，我们旨在阐明分子伴侣 UNC-45 和 Hsp90 协助肌球蛋白头部折叠的精确分子机制，这对于应力诱导损伤的发育和修复过程中的肌小节组装至关重要了解这些机制是肌肉发育和功能的核心问题，它也与许多类别的折叠和修复高度相关。我们最近发现肌球蛋白获得了一种新的构象，它以正常速率水解 ATP，但在 UNC-45 存在的情况下，肌动蛋白丝易位的能力大大降低，并且被逆转。由 Hsp90 引起的，提出了关于这些伴侣在肌球蛋白折叠和修复以及肌丝组装中的确切作用的重要问题，在我们最近发表的初步研究的指导下，我们在期间捕获了这一点。在肌球蛋白组装或修复过程中，UNC-45 帮助肌球蛋白头达到其天然构象，并随后将其锁定在防止过早动力冲程的状态；在成功组装到肌节或肌球蛋白头修复后，这种状态会被 Hsp90 缓解。通过两个专家研究实验室之间的独特合作，结合体外和体内分析进行测试。在目标 1 中，我们将使用诱变、生化和生物物理测定，包括。肌球蛋白依赖性肌动蛋白丝滑动测定，建立介导 UNC-45 不同独特功能的 UNC-45 结构域和关键氨基酸区域。在目标 2 和 3 中，我们将使用秀丽隐杆线虫作为模型系统的力量。检查突变 UNC-45 蛋白和肌节组装之间的功能关系（目标 2），以及 UNC-45 和 Hsp90 自身以及与肌球蛋白关联的动态在修复受损的肌球蛋白头期间（目标 3），我们的假设如果得到证实，将代表肌球蛋白生物学的新范式，不仅可以用于治疗因肌节蛋白突变引起的横纹肌疾病（骨骼肌病和心肌病）。），同时也是针对肿瘤侵袭性的问题。