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: 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
• 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)

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）主要是由整合素介导的，整联蛋白是一组通过其细胞外结构域与ECM蛋白结合的杂型跨膜受体。在ECM互动后，整联蛋白群集和转导信号转移到细胞内室中，从而形成了称为局灶性粘连（FAS）的大蛋白质复合物（FAS），将整联蛋白细胞质尾巴（CTS）连接到肌动蛋白细胞骨架。后一个步骤，即FAS的形成及其与肌动蛋白的联系，促进了牢固的细胞粘附。此外，它允许调节动态粘合过程，例如细胞扩散和迁移。我们的长期目标是获得对FAS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，我们一直专注于FAS-整联蛋白连接激酶（ILK）的主要组成部分。最初被发现是一种结合整合素2 CTS的整合蛋白连接的蛋白质，它已被确定为一种多功能蛋白，该蛋白质可以在整联蛋白和肌动蛋白之间传播各种机械和生化信号。 ILK函数的关键初始步骤是其与Pinch的紧密结合 - 包含LIM的适配器。这种相互作用不仅促进了小说对整联蛋白粘附位点的定位，而且还创建了一个稳定的平台，该平台可以容纳许多蛋白质，以调节动态FA组装和不同的信号通路。在过去的几年中，我们在建立ILK/PINCH网络的分子景观方面取得了重大进展，并在各种细胞过程中表明了它如何以时空方式发挥作用。与临床科学家合作，我们还表明，在人类心脏失败的人心脏中，幼虫/捏合综合体异常升高，这表明它直接参与心脏功能障碍。巧合的是，最近在小鼠中的一项研究表明，G-肌动蛋白隔离肽Thymosin beta-4（TB4）可能通过调节ILK/PINCH介导的细胞迁移和生存率来修复心脏损伤。尽管这导致了广泛的随访调查，并且针对治疗心脏损伤患者的基于TB4的第1A期临床试验启动，但潜在的分子机制仍然晦涩难懂。在初步研究中，我们发现了一种新型的ILK/PINCH介导的整联蛋白 - 肌动蛋白链接，这对于细胞迁移和生存至关重要。该链接似乎由TB4动态调节。在下一阶段，我们将使用多学科的结构/功能方法来大力研究这种联系及其对TB4的调节。这些研究将导致一个新的范式来理解ILK/捏合介导的细胞粘附。它们还将影响基于TB4的心脏障碍疗法以及其他疾病。公共卫生相关性：整联蛋白连接激酶（ILK）和lim型适配器之间的异质复合物在传输细胞外基质和肌动蛋白细胞骨架之间传输信息方面起着核心作用。该复合物的失调最近已与心脏病发作有关，其自然存在的人肽Thymosin beta-4的调节已被证明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/肌动蛋白链接的分子基础，以及如何通过TB4调节，这可能会导致对ILK/PINCH功能的基本了解，并影响基于TB4的心脏病治疗。