Role of the Tail Domain in Vinculin Function

尾部结构域在纽蛋白功能中的作用

• 批准号: 7933650
• 负责人: Sharon L Campbell
• 金额: $ 11.1万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-16 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7933650
• 关键词: Actinin; Actins; Adherens Junction; Adhesions; Binding; Binding Sites; Biochemical; Biological; Biological Process; Body part; C-terminal; Cadherins; Cell Adhesion Molecules; Cell Line; Cell Shape; Cell Survival; Cells; Complex; Cytoskeletal Proteins; Cytoskeleton; Data; Defect; Embryo; Embryonic Development; Exhibits; Extracellular Matrix; F-Actin; Focal Adhesions; Goals; Head; Inositol; Integrins; Ligand Binding; Ligands; Lipids; Location; Mechanics; Mediating; Membrane; Modeling; Molecular; Molecular Conformation; Movement; Mus; N-terminal; Nature; PTK2 gene; Phenotype; Phosphatidylinositol 4,5-Diphosphate; Phospholipid Interaction; Phospholipids; Phosphorylation; Phosphorylation Site; Play; Polymers; Process; Property; Proteins; Regulation; Regulatory Element; Reporting; Role; Scaffolding Protein; Signal Transduction; Site; Structure; Tail; Talin; Testing; Tumor Suppressor Proteins; Variant; Vinculin; abstracting; base; cancer cell; cell motility; design; gene function; human disease; insight; migration; mutant; novel therapeutic intervention; numb protein; paxillin; receptor; scaffold; tumorigenic

DESCRIPTION (provided by applicant): This proposal is focused on vinculin, a cytoskeletal protein that is a prominent component of focal adhesions and adherens junctions. Vinculin is critical for cell migration, cell survival and embryogenesis and disruption of vinculin expression in mice results in an embryonic lethal phenotype. Vinculin functions as a mechanical linker between transmembrane integrin receptors and the actin cytoskeleton through association with cell adhesion molecules. Release of autoinhibitory head/tail interactions is believed to activate vinculin's function as a scaffold protein to facilitate assembly of multi-protein networks important for modulation of cytoskeleton structure and for downstream signaling. Although vinculin binds to a large number of cytoskeletal proteins, in many cases, we do not understand the nature of the interaction or functional significance. For example, the role of paxillin interactions and with the vinculin tail (Vt) domain in vinculin function is not known. In addition, several functional roles for acidic phospholipids (PL) have been proposed, including the involvement of acidic PLs in the activation process as well in regulating vinculin function once vinculin is activated. While recent studies suggest that vinculin/PL interactions promote uncoupling of adhesion sites from the actin cytoskeleton, our preliminary data indicates that these studies were conducted with mutants that are likely to multiple defects, including PL binding. Thus, while acidic PLs, specifically inositol 4, 5 bisphosphate, is believed to play an important role in vinculin regulation and function, its role remains unclear. Our efforts will focus on NMR, biophysical, biochemical and cell biological studies of vinculin, with the primarily focus on the role of ligand interactions with Vt. We will investigate the structural features of Vt, interactions of wt Vt with acidic PLs and paxillin, and explore the importance of these interactions in the biological function of vinculin. The specific aims of this proposal are to investigate the: 1) Regulation of vinculin through PL binding. 2) Structural basis for Vt/paxillin complex formation and the role of these interactions in controlling vinculin function. PUBLIC HEALTH RELEVANCE Vinculin is an essential protein involved controlling cell shape and motility, in part by anchoring actin polymers to the membrane. This function also extends to cancer cells, by regulating their movement and proliferation to other parts of the body. Hence, not too surprising, vinculin exhibits properties of a tumor suppressor protein. The activity of vinculin is controlled by regulating auto-inhibitory or `self' interactions between its head and tail domain. The goal of this effort is to characterize tail domain interactions with select proteins and lipids, to better understand how these binding interactions regulate vinculin activity and function. Results obtained from these studies may aid in developing novel therapeutic approaches for counteracting aberrant vinculin activity in human disease.

描述（由申请人提供）：该提案的重点是纽蛋白，一种细胞骨架蛋白，是粘着斑和粘附连接的重要组成部分。纽蛋白对于细胞迁移、细胞存活和胚胎发生至关重要，小鼠中纽蛋白表达的破坏会导致胚胎致死表型。纽蛋白通过与细胞粘附分子结合，充当跨膜整合素受体和肌动蛋白细胞骨架之间的机械连接器。自抑制头/尾相互作用的释放被认为可以激活纽蛋白作为支架蛋白的功能，以促进多蛋白网络的组装，这对于细胞骨架结构的调节和下游信号传导很重要。尽管纽蛋白与大量细胞骨架蛋白结合，但在许多情况下，我们并不了解相互作用的本质或功能意义。例如，桩蛋白相互作用以及与纽蛋白尾部 (Vt) 结构域在纽蛋白功能中的作用尚不清楚。此外，还提出了酸性磷脂 (PL) 的多种功能作用，包括酸性 PL 参与激活过程以及在纽蛋白激活后调节纽蛋白功能。虽然最近的研究表明纽蛋白/PL 相互作用促进粘附位点与肌动蛋白细胞骨架的解偶联，但我们的初步数据表明这些研究是针对可能存在多种缺陷（包括 PL 结合）的突变体进行的。因此，虽然酸性 PL，特别是肌醇 4、5 二磷酸，被认为在纽蛋白调节和功能中发挥重要作用，但其作用仍不清楚。我们的工作将集中于纽蛋白的核磁共振、生物物理、生物化学和细胞生物学研究，主要关注配体与 Vt 相互作用的作用。我们将研究 Vt 的结构特征、wt Vt 与酸性 PL 和桩蛋白的相互作用，以及探索这些相互作用在纽蛋白生物学功能中的重要性。该提案的具体目的是研究：1) 通过 PL 结合调节纽蛋白。 2) Vt/桩蛋白复合物形成的结构基础以及这些相互作用在控制纽蛋白功能中的作用。公共卫生相关性 粘蛋白是一种重要的蛋白质，参与控制细胞形状和运动，部分通过将肌动蛋白聚合物锚定在细胞膜上。通过调节癌细胞向身体其他部位的运动和增殖，这种功能也延伸到癌细胞。因此，纽蛋白表现出肿瘤抑制蛋白的特性也就不足为奇了。纽蛋白的活性是通过调节其头部和尾部结构域之间的自抑制或“自我”相互作用来控制的。这项工作的目标是表征尾部结构域与选定蛋白质和脂质的相互作用，以更好地了解这些结合相互作用如何调节纽蛋白活性和功能。从这些研究中获得的结果可能有助于开发新的治疗方法来对抗人类疾病中异常的纽蛋白活性。