Molecular mechanisms of Tie2/Angiopoietin signaling initiation

Tie2/血管生成素信号传导启动的分子机制

基本信息

批准号：
9159077
负责人：
DIMITAR B NIKOLOV
金额：
$ 44.81万
依托单位：
SLOAN-KETTERING INST CAN RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-01 至 2020-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9159077
关键词：
Agonist Angiopoietin-2 Angiopoietins Binding Biochemical Biological Biological Assay Cell Line Cell surface Cells Characteristics Chemicals Complement Complex Data Engineering Event Fluorescence Resonance Energy Transfer Glycoproteins Goals Individual Insecta Integrins Kinetics Length Life Ligands Ligation Lymphatic System Maintenance Mediating Mediator of activation protein Methods Molecular Monitor Phosphotransferases Play Production Property Proteins Receptor Protein-Tyrosine Kinases Role Signal Transduction Spectrum Analysis Structure Surface System TIE-2 Receptor Techniques Thermodynamics Transmembrane Domain Vascular System Work X-Ray Crystallography abstracting analytical ultracentrifugation angiogenesis base biological systems biophysical analysis extracellular in vivo microcalorimetry milligram overexpression receptor research study

项目摘要

Abstract The angiopoietins are a small class of secreted glycoproteins that play key roles in the maturation and maintenance of the mammalian vascular and lymphatic systems. They exert their effects through the Tie receptor tyrosine kinases. All four angiopoietins (Ang1-4) directly bind Tie2, while none of them binds the related Tie1, although the latter has been shown to modulate the Ang/Tie2 signaling. Integrins, and in particular a5b1, are involved in regulating Ang1-dependent angiogenesis and were shown to directly interact with Tie2. The Ang/Tie signaling is unique among receptor kinase-ligand systems in that distinct angiopoietin ligands, although all highly homologous, may function as agonist or antagonist in a context dependent manner. A detailed understanding of the mechanisms of Angiopoietin/Tie signaling and their precise function during angiogenesis requires a comprehensive structural and biophysical analysis of the angiopoietins, of the Tie receptors and their co-receptors, as well as of their interactions. We will use X-ray crystallography, combined with other biophysical, biochemical and cell-biological techniques, to study these molecules. We have previously determined the structures of Tie2, Ang1, Ang2, as well as of the Tie2/Ang1 and Tie2/Ang2 complexes, revealing important and unique characteristics of Tie2 signaling initiation. We also performed FRET-based studies on live cells to monitor the Tie1/Tie2 interactions on the cell surface. An important conclusion of our experiments is that the distinct signaling properties of the individual angiopoietins are likely the result of Tie2 co-receptors that respond differently to the different ligands. Therefore, we now propose to study the molecular mechanisms by which co-receptors modulate, in a regulated and cell/context-dependent manner, the Ang/Tie2 signaling events. We specifically propose to investigate the roles of Tie1 and intergrin a5b1. Finally, our ultimate goal is to determine crystal structures of the complete Tie2 receptor, including its transmembrane region, alone and in complex with ligands and co- receptors, and we will work on the production and structural characterization of functional full-length Tie proteins. + PHS 398/2590 (Rev. 05/01)

抽象的血管生成素是一小部分分泌的糖蛋白，在成熟中起关键作用并维持哺乳动物血管和淋巴系统。他们通过绑带受体酪氨酸激酶。所有四个血管生成素（Ang1-4）直接结合TIE2，而它们都没有结合相关的TIE1，尽管已显示后者调节ANG/TIE2信号传导。整合素，以及特定的A5B1参与调节Ang1依赖性血管生成，并被证明直接与TIE2互动。 ANG/TIE信号在受体激酶 - 配体系统中是独一无二的血管生成素配体虽然所有高度同源，但在某种程度上可能是激动剂或拮抗剂依赖方式。对血管生成素/TIE信号的机制的详细理解及其血管生成期间的精确功能需要对血管生成蛋白，TIE受体及其共受体以及它们的相互作用。我们将使用X射线晶体学结合其他生物物理，生化和细胞生物学技术，以研究这些技术分子。我们以前已经确定了TIE2，ANG1，ANG2以及TIE2/ANG1的结构和TIE2/ANG2复合物，揭示了TIE2信号启动的重要和独特的特征。我们还对活细胞进行了基于FRET的研究，以监测细胞表面上的TIE1/TIE2相互作用。我们实验的一个重要结论是，个体的不同信号传导特性血管生成素可能是TIE2共受体对不同配体反应不同的结果。因此，我们现在建议研究共受体调节的分子机制受调节和细胞/上下文依赖性方式，ANG/TIE2信号事件。我们特别建议研究TIE1和Intergrin A5B1的作用。最后，我们的最终目标是确定完整的TIE2受体，包括其跨膜区域，单独并与配体和共同体复杂化受体，我们将致力于功能性全长领带的生产和结构表征蛋白质。 + PHS 398/2590（修订版05/01）