Regulation of Tie2 activation by homo- and hetero-oligomerization

通过同源和异源寡聚调节 Tie2 激活

基本信息

批准号：
9287102
负责人：
KATHRYN M FERGUSON
金额：
$ 38.32万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-04-01 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9287102
关键词：
Address Affect Agonist Allosteric Regulation Angiogenesis Inhibitors Angiopoietin-2 Angiopoietins Antibodies Attention Automobile Driving Binding Binding Sites Biochemical Biological Biophysics Blood Vessels CSF1 gene Cell Proliferation Cells Complex Data Development Dimerization Disease Distal Endothelial Cells Epidermal Growth Factor Receptor Family Family member Fibroblast Growth Factor Receptors Fibronectins Funding Goals Growth Factor Heterodimerization Homeostasis Homo Homodimerization Human Immunoglobulin Domain In Vitro Inflammation Intervention Investigation Lead Learning Ligand Binding Ligand Binding Domain Ligands Malignant Neoplasms Mediating Membrane Molecular Molecular Conformation Mutation Nature Oncogenic Orphan Outcome PDGFRB gene Phage Display Pharmacology Play Protein Tyrosine Kinase Protein Tyrosine Phosphatase Reagent Receptor Activation Receptor Protein-Tyrosine Kinases Regulation Reporting Role Signal Transduction Site Somatic Mutation Structure Testing Therapeutic Therapeutic Intervention Therapeutic antibodies Tumor Angiogenesis angiogenesis antibody libraries base cell motility crosslink dimer extracellular insight novel strategies novel therapeutics prototype receptor receptor function receptor protein tyrosine phosphatase-beta synthetic antibodies targeted agent targeted treatment therapeutic development vascular endothelial protein tyrosine phosphatase

项目摘要

Abstract The Tie family of receptor tyrosine kinases (RTKs) are involved in both vascular homeostasis and in angiogenesis. Both the receptors and their angiopoietin (Ang) ligands are attractive targets for pharmacologic intervention in cancer, inflammation and other disease states. An impediment to development of therapeutic agents is the current incomplete understanding of the mechanisms of activation of Tie receptors. Whereas RTKs such as EGFR, Kit and FGFR are well known to be regulated by growth factor-induced dimerization, for the Tie receptors, studies to date have failed to reveal the mechanism of ligand-induced receptor activation. The activating, oligomeric Ang ligands all bind to Tie2, with signaling outcomes that are context dependent and are modulated by co-receptors including the orphan family member Tie1. We have shown that the extracellular region (ECR) of Tie2 forms a ligand-independent dimer that is mediated by its membrane-proximal fibronectin type III (FNIII) domains, and is essential for Tie2 activation in cells. The oligomeric Ang ligands are known to bind to the membrane distal domains of Tie2. The Tie receptors thus differ from most RTKs in that an oligomeric ligand regulates an already oligomeric receptor. Whether signaling arises through allosteric changes in a receptor dimer or the promotion of receptor crosslinking or clustering remains unclear (but is a focus of our proposal). For several RTKs with immunoglobulin domains in their membrane-proximal regions (KIT, PDGFR and Fms/CSF1-R), homotypic interactions between membrane-proximal regions are important for receptor dimerization and activation, and disruption of these interactions by antibody binding or mutation blocks receptor activation. We propose that interactions involving the membrane-proximal FNIII domains of Tie receptors can also be targeted therapeutically. Further, we suggest that Tie receptors may serve as a prototype for the 40% of human RTKs that have membrane-proximal FNIII domains. To gain insight into how the oligomeric Ang ligands bind and activated a dimeric RTK, we will use a combination of structural, biochemical and cellular approaches to address the consequences of binding of defined, oligomeric Ang ligands to the Tie2 ECR dimer. We will also determine how ligand binding and signaling are influenced by the presence of Tie1 and the RPTPβ, both of which interact directly with Tie2. Our overall goal is to build a detailed molecular understanding of how the interactions mediated by the ECR of Tie2 regulate receptor activity, and to exploit this information to develop antibody modulators of Tie receptor activation. Our specific aims ask three questions: 1. How do angiopoietin ligands regulate Tie2? 2. How do Tie1 and RPTPβ modulate the effects of Ang ligands on Tie2 activity? 3. Can specific antibodies selectively block subsets of Tie2 interactions?

抽象的受体酪氨酸激酶（RTK）的领带家族参与了血管稳态和血管生成。接收器及其血管生成素（ANG）配体都是药理学的有吸引力的靶标干预癌症，感染和其他疾病状态。障碍治疗的发展药物是当前对TIE受体激活机制的不完全理解。然而众所周知，诸如EGFR，KIT和FGFR之类的RTK受生长因子诱导的二聚化调节，因为迄今为止，TIE受体，研究未能揭示配体诱导的受体激活的机制。激活的低聚ANG配体均与TIE2结合，具有依赖上下文的信号传导结果由包括孤儿家庭成员TIE1在内的共受体调节。我们已经表明细胞外 TIE2的区域（ECR）形成了与配体无关的二聚体，该二聚体由其膜 - 纤维纤维蛋白介导 III型（FNIII）域，对于细胞中的TIE2激活至关重要。众所周知的寡聚ang配体结合TIE2的膜远端结构域。因此，领带受体与大多数RTK不同，因为寡聚配体调节已经是低聚的受体。是否通过变构产生信号受体二聚体的变化或受体交联或聚类的促进尚不清楚（但是是一个我们的提议的重点）。对于具有免疫球蛋白结构域中的几个RTK （KIT，PDGFR和FMS/CSF1-R），膜 - 透明区域之间的同型相互作用很重要用于受体二聚和激活，以及通过抗体结合或突变破坏这些相互作用阻断受体激活。我们提出相互作用涉及的系扎受体也可以治疗靶向。此外，我们建议绑带受体可以用作 40％具有膜含量FNIII结构域的人类RTK的原型。为了深入了解寡聚ang配体如何结合并激活二聚体RTK，我们将使用一个结构，生化和细胞方法的结合，以解决结合的后果定义为TIE2 ECR二聚体的低聚ANG配体。我们还将确定配体结合和信号传导受TIE1和RPTPβ的存在的影响，这两者都与TIE2直接相互作用。我们的总体目标是对TIE2的ECR介导的相互作用如何建立详细的分子理解。调节受体活性，并利用此信息来开发TIE受体的抗体调节剂激活。我们的具体目的提出了三个问题： 1。血管生成素配体如何调节TIE2？ 2. TIE1和RPTPβ如何调节ANG配体对TIE2活性的影响？ 3。特定的抗体可以选择性地阻断TIE2相互作用的子集吗？