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: 8235954
• 负责人: JUN QIN
• 金额: $ 38.86万
• 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 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8235954
• 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; 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; cardiac repair; 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; research study; spatiotemporal; three dimensional structure; thymosin beta(4)

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 ¿ 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.

细胞与细胞外基质(ECM)的附着在多种生理和病理过程中起着至关重要的作用 流程。这种相互作用(细胞黏附)主要由整合素介导，整合素是一组异二聚体 通过细胞外域与ECM蛋白结合的跨膜受体。在ECM接洽后， 整合素聚集并将信号传递到细胞内，导致大蛋白的形成 将整合素细胞质尾巴(CT)连接到肌动蛋白细胞骨架的复合体称为焦点粘连(FA)。 后一步，即FAs的形成及其与肌动蛋白的连接，促进了细胞的牢固黏附。此外，它还 允许调节动态粘合过程，如细胞扩散和迁移。我们的长期目标是 为了获得对FAs的详细分子理解，并阐明它们是如何与肌动蛋白和 在不同的粘合过程中进行调制。为此，我们一直专注于以下主要组成部分 Fas整合素连接的激酶(ILK)。最初被发现是一种与整合素结合的整合素连接蛋白 CTS、ILK是一种多功能蛋白质，传递多种机械和生化反应。 整合素和肌动蛋白之间的信号。ILK功能的一个关键初始步骤是它与Pinch-a LIM-的紧密绑定 包含转接器。这种相互作用不仅促进了ILK定位到整合素黏附位点，而且还 创建一个稳定的平台，其中包含许多蛋白质来调节动态的FA组装和不同的信号 小路。在过去的几年里，我们在构建分子 ILK/PINCH网络的情况，并展示了它如何以时空的方式在不同的 细胞过程。在与临床科学家的合作中，我们还表明ILK/PINCH复合体是 在衰竭的心脏中异常升高，表明它直接参与了心脏功能不全。 巧合的是，最近对小鼠的一项研究表明，一种G-肌动蛋白隔离肽，胸腺素β-4(TB4)，可能 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 广泛的随访调查和启动了一项以TB4为基础的治疗心脏的1期临床试验 对于受伤患者，其潜在的分子机制仍不清楚。在初步调查中，我们有 发现了一种新的ILK/Pinch介导的整合素-肌动蛋白连接，它可能对细胞迁移和 生死存亡。这种连锁似乎受Tb4的动态调节。在我们的下一阶段研究中，我们将使用 多学科结构/功能方法，大力研究这种联系及其调控。 这些研究将为理解ILK/Pinch介导的细胞黏附提供一个新的范式。他们会 也对基于TB4的心脏疾病和可能的其他疾病的治疗产生影响。