Molecular Basis of ILK/PINCH Function in Cell Adhesion

ILK/PINCH 细胞粘附功能的分子基础

基本信息

批准号：
7669735
负责人：
JUN QIN
金额：
$ 39.25万
依托单位：
CLEVELAND CLINIC LERNER COM-CWRU
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-04-01 至 2013-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7669735
关键词：
Actins Adhesions Adhesives Binding Biochemical Blood Circulation C-terminal Cardiac Cell Adhesion Cell Adhesion Molecules Cell Shape Cell Survival Cell physiology Cell-Matrix Junction Cells Cellular biology Clinical Clinical Trials Collaborations Complex Cytoplasmic Tail Cytoskeleton Data Dilated Cardiomyopathy Disease Dynamic pinch Extracellular Domain Extracellular Matrix Extracellular Matrix Proteins Family Focal Adhesions Functional disorder G Actin Genetic Goals Heart Heart Diseases Heart Injuries Heart failure Human Integrin Binding Integrins Investigation Knowledge LIM Domain LIMS1 gene Lead Learning Life Link Mechanics Mediating Methods Microfilaments Modeling Molecular Mus Mutate Mutation Myocardial Infarction NMR Spectroscopy Nature Pathologic Processes Pathway interactions Patients Peptides Phase Physiological Physiological Processes Play Process Protein Array Protein Binding Protein Dynamics Proteins Recruitment Activity Regulation Reporting Role Scientist Sequence Alignment Series Signal Pathway Signal Transduction Site Site-Directed Mutagenesis Specificity Stress Fibers Structure Tail Testing Therapeutic Effect Time adhesion process base cell assembly cell motility design extracellular follow-up human disease in vivo insight integrin-linked kinase link protein migration mouse model multidisciplinary mutant novel polymerization protective effect protein complex public health relevance receptor binding repaired research study spatiotemporal three dimensional structure thymosin beta(4)

项目摘要

DESCRIPTION (provided by applicant): The attachment of cells to extracellular matrix (ECM) is crucial for a variety of physiological and pathological processes. This interaction (cell adhesion) is mediated primarily by integrins, a group of heterodimeric transmembrane receptors that bind to ECM proteins via their extracellular domains. Upon ECM engagement, integrins cluster and transduce signals into intracellular compartment leading to the formation of large protein complexes called focal adhesions (FAs) that connect integrin cytoplasmic tails (CTs) to the actin cytoskeleton. This latter step, i.e., the formation of FAs and their linkage to actin, promotes firm cell adhesion. Furthermore, it allows regulation of dynamic adhesive processes such as cell spreading and migration. Our long term goal is to obtain a detailed molecular understanding of FAs and to elucidate how they are connected to actin and modulated during various adhesive processes. To this end, we have been focusing on a major component of FAs - integrin-linked kinase (ILK). Originally discovered as an integrin linking protein that binds to integrin 2 CTs, ILK has been established as a multifunctional protein that transmits diverse mechanical and biochemical signals between integrins and actin. A key initial step for ILK function is its tight binding to PINCH - a LIM- containing adaptor. This interaction not only promotes the localization of ILK to integrin adhesion sites but also creates a stable platform that harbors many proteins to regulate dynamic FA assembly and diverse signaling pathways. Over the past several years, we have made a major progress towards building a molecular landscape of the ILK/PINCH network and showed how it functions in a spatiotemporal manner in various cellular processes. In collaboration with clinical scientists, we have also shown that the ILK/PINCH complex is abnormally elevated in failing human hearts, suggesting its direct involvement in cardiac dysfunction. Coincidently, a recent study in mice has shown that a G-actin sequestering peptide, thymosin beta-4 (tb4), may repair cardiac damage by modulating the ILK/PINCH-mediated cell migration and survival. While this has led to widespread follow-up investigations and the launching of a tb4-based phase1A clinical trial on treating heart injury patients, the underlying molecular mechanism remains obscure. In preliminary investigation, we have discovered a novel ILK/PINCH-mediated integrin-actin linkage that may be crucial for cell migration and survival. This linkage appears to be dynamically regulated by tb4. In the next phase of our study, we will use multidisciplinary structural/functional approach to vigorously investigate this linkage and its regulation by tb4. The studies will lead to a new paradigm for understanding the ILK/PINCH-mediated cell adhesion. They will also impact on the tb4-based therapy of cardiac disorder and possibly other diseases. PUBLIC HEALTH RELEVANCE: The heterocomplex between integrin-linked kinase (ILK) and LIM-only adaptor PINCH plays a central role in transmitting information between extracellular matrix and actin cytoskeleton. Dysregulation of this complex has been recently linked to heart attack and its regulation by a naturally occurring human peptide, thymosin beta-4, has been shown to exert therapeutic effect in mouse models. Our proposal will elucidate the molecular basis of the ILK/PINCH-mediated ECM/actin linkage and how it is regulated by tb4, which may lead to fundamental understanding of the ILK/PINCH function and also impact on tb4-based therapy of heart disease.

描述（由申请人提供）：细胞与细胞外基质（ECM）的附着对于多种生理和病理过程至关重要。这种相互作用（细胞粘附）主要由整联蛋白介导，整联蛋白是一组异二聚体跨膜受体，通过其胞外结构域与 ECM 蛋白结合。 ECM 参与后，整合素聚集并将信号转导至细胞内区室，从而形成称为粘着斑 (FA) 的大型蛋白质复合物，将整合素细胞质尾部 (CT) 连接到肌动蛋白细胞骨架。后一步，即 FA 的形成及其与肌动蛋白的连接，促进牢固的细胞粘附。此外，它还可以调节动态粘附过程，例如细胞扩散和迁移。我们的长期目标是获得对 FA 的详细分子理解，并阐明它们如何与肌动蛋白连接并在各种粘合过程中进行调节。为此，我们一直关注FAs的一个主要成分——整合素连接激酶（ILK）。 ILK 最初被发现是一种与整合素 2 CT 结合的整合素连接蛋白，现已被确定为一种多功能蛋白，可在整合素和肌动蛋白之间传递多种机械和生化信号。 ILK 功能的关键初始步骤是其与 PINCH（一种包含 LIM 的适配器）的紧密结合。这种相互作用不仅促进 ILK 定位于整合素粘附位点，而且还创建了一个稳定的平台，其中包含许多蛋白质来调节动态 FA 组装和多种信号通路。在过去的几年里，我们在构建 ILK/PINCH 网络的分子景观方面取得了重大进展，并展示了它如何在各种细胞过程中以时空方式发挥作用。我们与临床科学家合作，还发现 ILK/PINCH 复合物在衰竭的人类心脏中异常升高，表明其直接参与心脏功能障碍。巧合的是，最近的一项小鼠研究表明，G 肌动蛋白隔离肽胸腺素 beta-4 (tb4) 可以通过调节 ILK/PINCH 介导的细胞迁移和存活来修复心脏损伤。虽然这导致了广泛的后续研究并启动了基于 tb4 的治疗心脏损伤患者的 1A 期临床试验，但潜在的分子机制仍然不清楚。在初步研究中，我们发现了一种新的 ILK/PINCH 介导的整合素-肌动蛋白连接，该连接可能对细胞迁移和存活至关重要。这种联系似乎是由 tb4 动态调节的。在我们下一阶段的研究中，我们将使用多学科结构/功能方法来大力研究这种联系及其受tb4的调节。这些研究将为理解 ILK/PINCH 介导的细胞粘附带来新的范例。它们还将影响基于 tb4 的心脏病和可能的其他疾病的治疗。公共卫生相关性：整合素连接激酶 (ILK) 和仅 LIM 接头 PINCH 之间的异质复合物在细胞外基质和肌动蛋白细胞骨架之间传递信息中发挥着核心作用。最近，这种复合物的失调与心脏病有关，而天然存在的人类肽胸腺肽β-4对其的调节已被证明可以在小鼠模型中发挥治疗作用。我们的建议将阐明 ILK/PINCH 介导的 ECM/肌动蛋白连接的分子基础以及它如何受 tb4 调节，这可能会导致对 ILK/PINCH 功能的基本了解，并对基于 tb4 的心脏病治疗产生影响。