Role of UNC-89 (obscurin) in sarcomere assembly and maintenance.

UNC-89（obscurin）在肌节组装和维护中的作用。

基本信息

批准号：
8836489
负责人：
GUY Martin BENIAN
金额：
$ 34.17万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-08 至 2019-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8836489
关键词：
Adaptor Signaling Protein Animal Model Ankyrins Antibodies Binding Biochemical Biochemistry Biological Process Caenorhabditis elegans Calcium Calcium Signaling Cardiomyopathies Characteristics Chronic Disease Complex Coupling Cullin 1 Cullin Proteins Development Diabetes Mellitus Elasticity Elderly Embryo Enzymes Family member Filament Genetic Models Grant Health Heart Homologous Gene Human Immobilization Kidney Failure Knockout Mice Lead Link Locomotion MEL Gene Maintenance Malignant Neoplasms Mediating Medical Microtubules Molecular Molecular Genetics Mus Muscle Muscle Contraction Muscular Atrophy Muscular Dystrophies Myofibrils Myopathy Myosin ATPase Nematoda PH Domain Pathogenesis Phosphotransferases Physiological Play Protein Kinase Protein phosphatase Proteins Regulation Reporting Role SH3 Domains Sarcomeres Sarcoplasmic Reticulum Scaffolding Protein Signal Pathway Signal Transduction Signaling Protein Stretching Striated Muscles Structure Tertiary Protein Structure Ubiquitin Ubiquitination base connectin copine cullin-3 genetic approach human disease insight katanin loss of function mouse model mutant novel obscurin polypeptide protein degradation scaffold titin kinase ubiquitin-protein ligase

项目摘要

DESCRIPTION (provided by applicant): Muscle sarcomeres contain a number of giant polypeptides (0.7-4 MDa). Much is currently known about the function of the largest of these polypeptides, vertebrate titin. Much less is known about the newest vertebrate member of this family, obscurin. The pathogenesis of one form of muscular dystrophy may involve obscurin. Obscurin is the homolog of UNC-89 in C. elegans. Essential features of UNC-89 as a signaling / scaffolding protein crucial for A-band/M-line assembly were discovered before obscurin was reported. To understand how UNC-89 is localized, and how it functions, we are taking a systematic approach for identifying and studying the function of its binding partners. We discovered that the Ig1-3 segment of UNC-89 interacts with CPNA-1, a copine domain protein. Although CPNA-1 is not required for initial assembly of UNC-89 at the M-line, it is required for it retention. CPNA-1 is located at both M-lines and dense bodies, whereas UNC-89 is located only at M-lines. Therefore, we hypothesize that there are proteins which direct assembly of UNC-89 solely to the M-line. UNC-89 Ig9-11 interacts with CUL-1 (cullin 1), and UNC-89 Ig2-3 interacts with MEL-26, a substrate recognition protein for CUL-3 (cullin 3). Cullins are scaffolds for assembly of the ubiquitination machinery. One function of the CUL-3/MEL-26 complex is to promote degradation of MEI-1 (katanin). Independently, the coI of this proposal, Stephan Lange, found that in mouse heart, degradation of sAnk1.5 is promoted by a cullin 3 substrate recognition protein, KCTD6, and this is dependent upon obscurin. We hypothesize that UNC-89 (obscurin) negatively regulates the activity of cullin complexes in muscle. We further hypothesize that UNC-89 interacts with other cullins or cullin 3 adaptor proteins, and there are substrates in addition to MEI-1. In humans, muscle atrophy is associated with immobilization, chronic diseases and advanced age. Since in muscle atrophy, degradation of sarcomeric proteins is upregulated, our studies have medical relevance. Also, our collaborator and coI of this grant, Ken Norman, has found that a key function of obscurin for organization of the SR, is conserved for UNC-89. In addition, UNC-89 was found to have a physiological role in EC coupling, and this involves the conserved RacGEF, VAV-1. We hypothesize that UNC-89 and VAV-1 interact, and that VAV-1 localization and function is dependent on UNC-89. Finally, we hypothesize that the binding partners and functional mechanisms discovered for UNC-89 in C. elegans are biologically relevant for mammalian striated muscle. Specific aims are: (1) determine mechanisms which direct assembly of UNC-89 solely to the M-line; (2) determine if other cullins interact with UNC-89, if there are additional substrates for MEL-26, and determine the biochemical effects of the UNC-89 to MEL-26 interaction; (3) define the biochemistry and functional consequence of interaction between UNC-89 and myosin; (4) investigate the molecular mechanism underlying UNC-89's role in calcium regulation; and (5) determine if functional interactions and molecular mechanisms identified for nematode UNC-89 are conserved for mammalian obscurin.

描述（由申请人提供）：肌肉肉瘤包含许多巨型多肽（0.7-4 MDA）。目前对这些多肽最大的脊椎动物滴定的功能有很多了解。对于这个家庭的最新脊椎动物，Imbisturin知之甚少。一种肌肉营养不良的一种形式的发病机理可能涉及掩盖蛋白。 Sigburin是秀丽隐杆线虫中UNC-89的同源物。在据报道，在据报道，在据报道，在据报道，在据报道，在据报道，unc-89作为A-band / M线组件至关重要的信号传导 /脚手架蛋白质的基本特征。为了了解UNC-89如何局部化以及它的功能，我们正在采用一种系统的方法来识别和研究其结合伙伴的功能。我们发现UNC-89的Ig1-3段与CPNA-1（一种cpna-1）相互作用，CPNA-1是一种蛋白质蛋白。尽管在M线上初始组装UNC-89的初始组装不需要CPNA-1，但保留它是必需的。 CPNA-1位于M线和致密体，而UNC-89仅位于M线。因此，我们假设有一些蛋白质将UNC-89直接组装的蛋白完全直接归为M线。 UNC-89 IG9-11与CUL-1（CULLIN 1）相互作用，UNC-89 IG2-3与CUL-3的底物识别蛋白MEL-26相互作用（Cullin 3）。库林是用于泛素化机制组装的脚手架。 CUL-3/MEL-26复合物的一个功能是促进MEI-1（Katanin）的降解。独立地，该提案的COI斯蒂芬·兰格（Stephan Lange）发现，在小鼠心脏中，sank1.5的降解是由cullin 3底物识别蛋白KCTD6促进的，这取决于易见的。我们假设UNC-89（胶蛋白）负调节肌肉中Cullin复合物的活性。我们进一步假设UNC-89与其他Cullins或Cullin 3适配器蛋白相互作用，并且除了MEI-1外，还有底物。在人类中，肌肉萎缩与固定，慢性疾病和高龄有关。由于在肌肉萎缩中，肌肉蛋白的降解被上调，我们的研究具有医学意义。此外，我们的合作者和COI肯·诺曼（Ken Norman）发现，SROBSURIN用于组织SR的关键功能是为UNC-89保留的。此外，发现UNC-89在EC耦合中具有生理作用，这涉及保守的RACGEF VAV-1。我们假设UNC-89和VAV-1相互作用，并且VAV-1的定位和功能取决于UNC-89。最后，我们假设在秀丽隐杆线虫中发现的UNC-89的结合伴侣和功能机制与哺乳动物横纹的肌肉具有生物学相关。具体目的是：（1）确定仅将UNC-89直接组装到M线上的机制；（2）确定其他Cullins是否与UNC-89相互作用，是否还有MEL-26的其他底物，并确定UNC-89与MEL-26相互作用的生化效应；（3）定义了UNC-89和肌球蛋白之间相互作用的生物化学和功能后果；（4）研究UNC-89在钙调节中的作用的分子机制；（5）确定针对线虫UNC-89鉴定的功能相互作用和分子机制是否为哺乳动物掩盖蛋白保守。