Obscurin & Myofibrils in Cardiac & Skeletal Muscle

暗色素

• 批准号: 7822220
• 负责人: ROBERT J BLOCH
• 金额: $ 1.06万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7822220
• 关键词: Actins; Address; Adenovirus Vector; Adult; Affect; Affinity; Ankyrins; Antibodies; Binding; Binding Sites; Biochemical; Biological Assay; C-terminal; Cardiac; Collaborations; Contractile Proteins; Coupled; Cytoskeleton; Elements; Epitopes; Gene Expression; Hand; Head; Hybrids; Hypertrophic Cardiomyopathy; Immunologic Techniques; Indium; Integral Membrane Protein; Label; Learning; Length; Link; Maps; Measurement; Membrane; Molecular Cloning; Morphogenesis; Morphology; Muscle Fibers; Muscular Dystrophies; Mutation; Myofibrillogenesis; Myofibrils; Myosin ATPase; PH Domain; Play; Proteins; Reaction; Reporting; Research Personnel; Rest; Role; Sarcomeres; Sarcoplasmic Reticulum; Signal Transduction; Site; Skeletal Muscle; Small Interfering RNA; Striated Muscles; Structure; Surface Plasmon Resonance; Testing; Thick; Thick Filament; Thin Filament; Transfection; Yeasts; connectin; knock-down; nebulin; obscurin; overexpression; programs; research study; scaffold; skeletal; uptake

DESCRIPTION (provided by applicant): In recent years, we have learned a great deal about the assembly of thick and thin filaments in striated muscle, and about the proteins that regulate the release and re-uptake of Ca2+ essential for the contractile cycle. We know much less, however, about the mechanisms that integrate thick and thin filaments into myofibrils, and about the proteins that organize the sarcoplasmic reticulum (SR) and transverse (t-) tubules so regularly around sarcomere. The recent discovery of obscurin offers new ways to address these questions. Obscurin is an approximately 800 kDa protein with structural homology to titin. It is the only protein of the titin superfamily that is concentrated, at least in part, at the periphery of sarcomeres, primarily around M-lines and Z-disks. Obscurin is composed largely of tandem Ig domains but also has signaling domains and, at its extreme COOH-terminus, a binding site for a small, integral membrane form of ankyrin 1 that is concentrated in the network SR. Given its apparent ability to concentrate at the periphery of the myofibril around M-lines and Z-disks and its high affinity for an integral protein of the SR membrane, obscurin is ideally suited to play key roles in assembling and organizing both the sarcomere and the SR. We propose to test this general hypothesis through 4 specific aims: (1) to learn how obscurin is organized with respect to key structures within sarcomeres; (2) to learn how obscurin binds to elements in the contractile apparatus; (3) to assess the effect on morphogenesis of the myofibrils and associated membranes of altering the activity of obscurin with siRNA and thru adenoviral overexpression of particular binding domains; and (4) to investigate the role of obscurin's binding to small ankyrin 1 in the assembly, organization and function of the SR. Mutations in proteins of the contractile apparatus, including some that affect the assembly or stability of contractile elements, have been implicated in hypertrophic cardiomyopathies and muscular dystrophies. The results of our experiments should reveal some of the key mechanisms involved in assembling contractile proteins into sarcomeres and in determining their association with the SR.

描述（由申请人提供）：近年来，我们对横纹肌中粗细丝的组装以及调节收缩周期必需的 Ca2+ 释放和再摄取的蛋白质了解了很多。然而，我们对将粗丝和细丝整合到肌原纤维中的机制，以及在肌节周围规则地组织肌浆网 (SR) 和横管 (t-) 的蛋白质知之甚少。最近发现的暗色蛋白为解决这些问题提供了新的方法。 Obscurin 是一种大约 800 kDa 的蛋白质，与肌联蛋白具有结构同源性。它是肌联蛋白超家族中唯一一种至少部分集中在肌节外围的蛋白质，主要集中在 M 线和 Z 盘周围。暗蛋白主要由串联 Ig 结构域组成，但也具有信号传导结构域，并且在其末端 COOH 末端有一个小完整膜形式的锚蛋白 1 的结合位点，该锚蛋白 1 集中在网络 SR 中。鉴于其明显能够集中在 M 线和 Z 盘周围的肌原纤维外围，并且其对 SR 膜的整合蛋白具有高亲和力，Obcurin 非常适合在肌节和肌节的组装和组织中发挥关键作用。 SR。我们建议通过 4 个具体目标来检验这一一般假设：（1）了解 obscurin 是如何根据肌节内的关键结构进行组织的； (2) 了解暗蛋白如何与收缩装置中的元件结合； (3) 评估用 siRNA 和通过特定结合域的腺病毒过表达改变暗蛋白活性对肌原纤维和相关膜形态发生的影响； (4)研究obscurin与小锚蛋白1的结合在SR的组装、组织和功能中的作用。 收缩器官的蛋白质突变，包括一些影响收缩元件的组装或稳定性的突变，与肥厚性心肌病和肌营养不良症有关。我们的实验结果应该揭示一些涉及将收缩蛋白组装成肌节并确定它们与 SR 关联的关键机制。

项目成果

Na,K-ATPase in skeletal muscle: two populations of beta-spectrin control localization in the sarcolemma but not partitioning between the sarcolemma and the transverse tubules.

骨骼肌中的 Na,K-ATP 酶：β-血影蛋白的两个群体控制肌膜中的定位，但不控制肌膜和横管之间的分配。

• DOI: 10.1242/jcs.114.4.751
• 发表时间: 2001
• 期刊: Journal of cell science
• 影响因子: 4
• 作者: Williams,MW;Resneck,WG;Kaysser,T;Ursitti,JA;Birkenmeier,CS;Barker,JE;Bloch,RJ
• 通讯作者: Bloch,RJ