Molecular Mechanisms of Cell Adhesion

计划摘要 这项最大化调查人员研究奖(MIRA)的提议与长期 国家普通医学科学研究所(NIGMS)的计划。我们的实验室连续收到了 NIGMS自2004年以来的资助，使我们能够在我们对 相邻细胞之间(粘连连接)以及细胞之间动态接触的机制 细胞和细胞外基质(局灶性粘连结构)。这些细胞连接，除了保持 动物细胞在一起，传递信号，控制施加在细胞上的压力。 在过去的16年里，我们做出了重要的机械发现，以帮助理解 ·细胞-细胞连接如何将组织中的细胞连接起来，以调节组织动态平衡，这对 提供上皮细胞的组织屏障，以及细胞迁移和增殖；以及 ·细胞连接如何启动和维持细胞黏附，同时调节底层细胞的组织 肌动蛋白通过建立一个细胞信号和基因转录调控中心来调节细胞骨架。 这样的过程是高度动态的，受到严格监管。我们的实验室专注于定义激活 我们在生物化学和活细胞中研究的这些细胞连接的关键调节机制。我们的 我们开发的新技术克服了重大的结构性问题，加速了我们的发现 生物学障碍使该领域停滞不前，也适用于许多其他结构生物学研究。 我们发现了talin如何激活vinculin，这是两种普遍表达的肌动蛋白结合蛋白，以稳定 局灶性粘连，从而抑制细胞迁移。我们的高分辨率纽蛋白晶体结构， 我们在生化和活细胞中证实，显示了自动抑制的分子内相互作用 使纽蛋白失活，从而防止纽蛋白与肌动蛋白细胞骨架结合。 另一方面，我们的高分辨晶体结构的a-连环蛋白，一个重要的细胞间介质 黏附，揭示了它的四级结构在细胞-细胞黏附中所起的机制作用。 形成了与肌动蛋白细胞骨架的动态连接。值得注意的是，我们的发现导致了机械- 关于细胞如何感知和传递力的细胞-细胞和细胞-基质连接的转导研究。 最近，我们发现脂质如何与纽蛋白、其心脏异构体Metavinculin和talin结合 调节局部粘连翻转。这些知识和专业知识是进一步发现的基础。 这还将侧重于质膜在细胞黏附中所扮演的未被充分研究的角色。 从长远来看，我们希望通过获得接近原子的分子来全面了解细胞的粘附性。 “合成”细胞连接的结构。细胞连接的调节和失调是 许多生物过程，如发育和癌症，以及我们提议的研究因此 既有基本的，也有潜在的翻译意义。

Program Summary This Maximizing Investigators’ Research Award (MIRA) proposal is directly relevant to the long-range plans of the National Institute of General Medical Sciences (NIGMS). Our laboratory received continuous NIGMS funding since 2004 that allowed us to make substantial advances in our understanding of the mechanisms of the dynamic contacts between neighboring cells (adherens junctions), as well as between cells and the extracellular matrix (focal adhesions structures). These cell junctions, in addition of holding animal cells together, communicate signals and control the stress placed upon cells. Over the past 16 years, we contributed important mechanistic discoveries towards an understanding of · how the cell-cell junctions connect cells in tissues to regulate tissue homeostasis that are crucial to provide the tissue barrier of epithelia, as well as cell migration and proliferation; and · how cell junctions initiate and maintain cell adhesion while regulating the organization of the underlying actin cytoskeleton by establishing a center for cell signaling and gene transcript regulation. Such processes are highly dynamic and tightly regulated. Our laboratory focused on defining the activation mechanisms of key regulators of these cell junctions that we studied biochemically and in live cells. Our discoveries were accelerated by our development of new techniques that overcame significant structural biology hurdles that stalled the field and that are applicable to many other structural biology studies. We discovered how talin activates vinculin, two ubiquitously expressed, actin-binding proteins, to stabilizes focal adhesions and thereby suppressing cell migration. Our high-resolution vinculin crystal structures, that we confirmed biochemically and in live cells, showed the auto-inhibitory intramolecular interactions that inactivate vinculin and thereby prevent vinculin from binding to the actin cytoskeleton. On the other hand, our high-resolution crystal structures of a-catenin, a crucial mediator of intercellular adhesions, revealed the mechanistic roles that its quaternary structures play in cell-cell adhesion and in the formation of the dynamic link to the actin cytoskeleton. Significantly, our discoveries led to mechano- transduction studies of cell-cell and cell-matrix junctions on how cells sense and transmit forces. More recently, we discovered how lipid binding to vinculin, to its cardiac isoform metavinculin, and to talin regulates focal adhesion turnover. This knowledge and expertise are the foundation for further discoveries that will additionally focus on the understudied role that the plasma membrane plays in cell adhesion. In the long run, we hope to gain a complete understanding of cell adhesion by attaining a near atomic structure of a “synthetic” cell junction. The regulation and dysregulation of cell junctions are fundamental to many biological processes such as development and cancer, and our proposed studies have therefore both basic and potentially translational significance.