Understanding the role of phospholipids in integrin signaling

了解磷脂在整合素信号传导中的作用

基本信息

批准号：
8469530
负责人：
STEPHEN G. SLIGAR
金额：
$ 27.94万
依托单位：
UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-06-01 至 2016-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8469530
关键词：
Adhesions Affect Affinity Arthritis Binding Biological Assay Biological Process Blood Platelets Cell Adhesion Cell Communication Cell Proliferation Cell Surface Receptors Cells Collaborations Complex Coupled Development Disease Embryonic Development Environment Event Fluorescence Goals Head Health Heart Hemostatic function Human Immune response Integrins Laboratories Length Ligand Binding Light Link Lipids Malignant Neoplasms Mediating Membrane Membrane Proteins Modeling Molecular Molecular Conformation Myocardial Infarction Nature Phosphatidylinositol 4,5-Diphosphate Phospholipids Play Positioning Attribute Process Proteins Regulation Research Resolution Role Sampling Signal Transduction Site-Directed Mutagenesis Solutions Specificity Stroke Structural Models Sum Surface System Talin Techniques Time Wound Healing adapter protein adhesion receptor base cell motility human disease in vivo mimetics molecular dynamics nanodisk nanoscale novel novel strategies programs research study simulation

项目摘要

DESCRIPTION (provided by applicant): Integrins are heterodimeric cell surface receptors involved in the regulation of cellular adhesion and cell-cell interactions. As such they play a critical role in many biological processes of importance to human health. The goal of our proposed research effort is to provide the first quantitative understanding of role of the membrane and its lipid composition on the mechanism of integrin activation and signaling. We use a novel approach by employing Nanodiscs, homogeneous self- assembled nanometer scale discoidal bilayers to provide precise control of the membrane composition. We couple this experimental approach with molecular dynamic simulations employing a novel membrane mimetic that allows enhanced sampling at an atomic resolution, thereby a detailed description of the interactions occurring at the protein-membrane interface. By focusing our experimental and theoretical thrusts on talin, a key activator of integrin involved in inside-out signaling, we answr questions as to how talin engages the membrane and how the presence of anionic phospholipids, in particular PIP2, regulates this important interaction. In addition, we dissect th mechanism of talin activation from its auto-inhibited form separating the contributions from interactions with phospholipids, and that of the effectors Rap1, RIAM, and PIPKgamma. Through this integrated research plan we seek to understand how the sum of these interactions regulates the activation of integrin and control its affinity for ligand binding.

描述（由申请人提供）：整联蛋白是异二聚体细胞表面受体，参与细胞粘附和细胞间相互作用的调节。因此，它们在许多对人类健康重要的生物过程中发挥着关键作用。我们提出的研究工作的目标是首次定量了解膜及其脂质成分对整合素激活和信号传导机制的作用。我们采用了一种新颖的方法，即采用纳米圆盘（Nanodiscs），即均匀的自组装纳米级盘状双层，以提供对膜成分的精确控制。我们将这种实验方法与采用新型膜模拟物的分子动力学模拟结合起来，该模拟物允许以原子分辨率增强采样，从而详细描述蛋白质-膜界面处发生的相互作用。通过将我们的实验和理论重点集中在talin（参与由内而外信号传导的整合素的关键激活剂）上，我们回答了有关talin如何与膜结合以及阴离子磷脂（特别是PIP2）的存在如何调节这种重要相互作用的问题。此外，我们从其自动抑制形式中剖析了talin激活的机制，将其与磷脂相互作用的贡献分开，以及效应器Rap1、RIAM和PIPKgamma的贡献。通过这个综合研究计划，我们试图了解这些相互作用的总和如何调节整合素的激活并控制其与配体结合的亲和力。