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）的附着对于多种生理和病理至关重要 流程。这种相互作用（细胞粘附）主要由整合素介导，整合素是一组异二聚体 通过细胞外结构域与 ECM 蛋白结合的跨膜受体。在 ECM 参与后， 整合素聚集并将信号转导至细胞内区室，从而形成大蛋白质 称为粘着斑 (FA) 的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 允许调节动态粘附过程，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和 在各种粘合过程中进行调节。为此，我们一直关注一个主要组成部分 FAs - 整合素连接激酶 (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 已被确定为一种多功能蛋白质，可传递多种机械和生化信息 整合素和肌动蛋白之间的信号。 ILK 功能的关键初始步骤是其与 PINCH（LIM-）的紧密结合 包含适配器。这种相互作用不仅促进 ILK 定位于整合素粘附位点，而且 创建一个稳定的平台，包含许多蛋白质来调节动态 FA 组装和多样化的信号传导 途径。在过去的几年里，我们在构建分子生物学方面取得了重大进展。 ILK/PINCH 网络的景观，并展示了它如何在各种情况下以时空方式发挥作用 细胞过程。通过与临床科学家的合作，我们还证明了 ILK/PINCH 复合物是 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 广泛的后续调查并启动基于 tb4 的治疗心脏的 1A 期临床试验 损伤患者中，潜在的分子机制仍然不清楚。在初步调查中，我们已 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至关重要 生存。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 tb4 的调节。 这些研究将为理解 ILK/PINCH 介导的细胞粘附提供新的范例。他们会 也对基于 tb4 的心脏病和可能的其他疾病的治疗产生影响。