Structure Analysis of Integrin Activation

整合素激活的结构分析

基本信息

批准号：
7496522
负责人：
Mark Jay Yeager
金额：
$ 34.42万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-09-21 至 2011-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7496522
关键词：
Address Affinity Agreement Algorithms Antibodies Apoptosis Arterial Fatty Streak Binding Biological Biological Process Blood Platelets Cardiovascular Diseases Cell Adhesion Cell Adhesion Molecules Cell physiology Cells Complex Computer software Coronary artery Cryoelectron Microscopy Cytoplasmic Tail DNA Sequence Rearrangement Data Disintegrins Docking Environment Event Extracellular Domain Family Fibrinogen Frequencies Goals Head Homology Modeling Human Image Image Analysis Individual Integrins Label Laboratories Length Ligand Binding Ligands Light Localized Location Macromolecular Complexes Manuals Maps Mechanics Mediating Membrane Proteins Methods Modeling Molecular Molecular Conformation Movement Myocardial Infarction Nature Neoplastic Cell Transformation Numbers Pathologic Processes Pathway interactions Peptides Phosphotransferases Physiological Platelet aggregation Population Price Proteins Reporting Research Personnel Resolution Roentgen Rays Rotavirus Rupture Signal Transduction Site Snake Venoms Staging Structural Models Structure Techniques Testing Therapeutic Agents Thrombosis Thrombus Time United States Wound Healing angiogenesis base cell motility design echistatin extracellular image processing image reconstruction improved insight migration molecular modeling mortality novel therapeutics particle polypeptide programs protein protein interaction receptor reconstruction research study success three dimensional structure

项目摘要

DESCRIPTION (provided by applicant): Cardiovascular disease is the major cause of mortality in the United States, primarily due to myocardial infarction resulting from rupture of an atherosclerotic plaque and subsequent thrombosis within a coronary artery. A key event that stimulates thrombus formation is platelet aggregation, which is mediated by the prototypical integrin aIIb¿3. Integrins are a family of heterodimeric transmembrane receptors which modulate cell adhesion, such as platelet aggregation, as well as other important biological processes such as cell migration, differentiation, proliferation and programmed cell death. Integrins accomplish these diverse functions by mediating dynamic linkages between extracellular adhesion molecules and the intracellular environment. Integrin functions are regulated by transmembrane signaling, which can occur as a consequence of binding extracellular ligands ("outside-in" signaling), as well as the binding of molecules to the cytoplasmic domains ("inside-out" signaling). We propose to use electron cryo-microscopy, image reconstruction and molecular modeling to examine the structure of the human platelet integrin aIIb¿3. Electron cryo-microscopy (cryo-EM) is a powerful technique by which macromolecular complexes such as membrane proteins can be examined in a native, physiological state. We have completed a 3D structure of the full-length, human platelet integrin aIIb¿3 in the low-affinity, inactive conformation. The X-ray structure of the aV¿3 ectodomain was then docked into the low resolution cryo-EM map. This combined approach allowed us to propose a model for the structural rearrangements associated with integrin activation. The overall goal of this project is to test this model for integrin activation, and our experiments are organized according to the following specific aims: Aim 1: Image analysis will be continued in order to improve the resolution of the 3D reconstruction of aIIb¿3 in the low-affinity state; Aim 2: A 3D map of the high-affinity state will be derived by analysis of aIIb¿3 with bound ligands; Aim 3: Antibody labeling will be used to localize specific sites within the high- and low-affinity states; Aim 4: Molecular models of the high- and low- affinity states will be derived by combining the cryo-EM maps, site-specific antibody labeling data, and homology models for individual integrin domains. The structural details revealed by these studies will provide insight into the molecular basis of integrin activation, relevant for the design of new therapeutic agents.

描述（由申请人提供）：心血管疾病是美国死亡的主要原因，主要是由于动脉粥样硬化斑块破裂和随后冠状动脉内血栓形成引起的心肌梗塞。刺激血栓形成的一个关键事件是血小板聚集。，这是由原型整合素 aIIb 介导的3. 整合素是异二聚跨膜受体家族，可调节细胞粘附，例如血小板聚集，以及其他重要的生物过程，例如细胞迁移、分化、增殖和程序性细胞死亡。整合素通过介导之间的动态联系来实现这些不同的功能。细胞外粘附分子和细胞内环境通过跨膜信号传导进行调节，跨膜信号传导是结合细胞外配体（“从外向内”信号传导）的结果。我们建议使用电子冷冻显微镜、图像重建和分子建模来检查人血小板整合素 aIIb 的结构。 3. 冷冻电子显微镜 (cryo-EM) 是一种强大的技术，可以在天然生理状态下检查膜蛋白等大分子复合物，我们已经完成了全长人血小板整合素 aIIb 的 3D 结构。 3 的低亲和力、非活性构象 aV¿然后将 3 胞外域对接到低分辨率冷冻电镜图中。这种组合方法使我们能够提出与整合素激活相关的结构重排模型。该项目的总体目标是测试该模型的整合素激活和我们的实验。根据以下具体目标进行组织：目标 1：将继续进行图像分析，以提高 aIIb 3D 重建的分辨率3 处于低亲和力状态；目标 2：通过分析 aIIb¿ 得出高亲和力状态的 3D 图。 3 结合配体；目标 3：将使用抗体标记来定位高亲和力状态和低亲和力状态内的特定位点；目标 4：将通过结合冷冻电镜导出高亲和力状态和低亲和力状态的分子模型这些研究揭示的结构细节将提供对整合素激活的分子基础的深入了解，与新治疗药物的设计相关。