Molecular Basis of ILK/PINCH Function in Cell Adhesion

ILK/PINCH 细胞粘附功能的分子基础

• 批准号: 8048076
• 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
• 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/8048076
• 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; Extracellular Domain; Extracellular Matrix; Extracellular Matrix Proteins; Family; Focal Adhesions; Functional disorder; G Actin; Genetic; Goals; Health; Heart; Heart Diseases; Heart Injuries; Heart failure; Human; Integrin Binding; Integrins; Investigation; 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 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; follow-up; human disease; in vivo; insight; integrin-linked kinase; link protein; migration; mouse model; multidisciplinary; mutant; novel; polymerization; protective effect; protein complex; receptor binding; repaired; research study; spatiotemporal; three dimensional structure; thymosin beta(4)

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）的附着对于各种生理和病理过程至关重要。这种相互作用（细胞粘附）主要由整合素介导，整合素是一组通过其细胞外结构域与ECM蛋白结合的异二聚体跨膜受体。在ECM接合后，整合素聚集并将信号传递到细胞内区室中，导致形成称为粘着斑（FA）的大蛋白质复合物，其将整合素胞质尾（CT）连接到肌动蛋白细胞骨架。这后一步骤，即，FA的形成及其与肌动蛋白的连接促进了牢固的细胞粘附。此外，它允许调节动态粘附过程，如细胞扩散和迁移。我们的长期目标是获得一个详细的分子理解的脂肪酸，并阐明它们是如何连接到肌动蛋白和调制过程中的各种粘合剂。为此，我们一直专注于FA的主要组成部分-整合素连接激酶（ILK）。ILK最初被发现为与整联蛋白2 CT结合的整联蛋白连接蛋白，现已被确立为在整联蛋白和肌动蛋白之间传递多种机械和生化信号的多功能蛋白。ILK功能的关键初始步骤是其与PINCH（一种含有LIM的接头）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，而且还产生了一个稳定的平台，该平台包含许多蛋白质以调节动态FA组装和多种信号传导途径。在过去的几年里，我们已经取得了重大进展，建立了ILK/PINCH网络的分子景观，并展示了它如何在各种细胞过程中以时空方式发挥作用。在与临床科学家的合作中，我们还发现ILK/PINCH复合物在衰竭的人类心脏中异常升高，表明其直接参与心功能障碍。巧合的是，最近在小鼠中的一项研究表明，G-肌动蛋白螯合肽，胸腺素β-4（tb 4），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调查和启动tb 4为基础的1A期临床试验治疗心脏损伤患者，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，可能是至关重要的细胞迁移和生存。这种联系似乎是由tb 4动态调节的。在下一阶段的研究中，我们将使用多学科的结构/功能的方法，大力调查这种联系和它的调节tb 4。这些研究将为理解ILK/PINCH介导的细胞粘附提供新的范式。它们也将影响以结核为基础的心脏疾病和其他疾病的治疗。公共卫生相关性：整合素连接激酶（ILK）和仅含LIM的接头PINCH之间的异源复合物在细胞外基质和肌动蛋白细胞骨架之间的信息传递中起着重要作用。这种复合物的调节异常最近与心脏病发作有关，并且其通过天然存在的人肽胸腺素β-4的调节已显示在小鼠模型中发挥治疗作用。我们的提案将阐明ILK/PINCH介导的ECM/肌动蛋白连接的分子基础以及它如何受到tb 4的调节，这可能会导致对ILK/PINCH功能的基本理解，并对基于tb 4的心脏病治疗产生影响。