Elucidation of a eukaryotic chemorepulsion mechanism

阐明真核化学排斥机制

基本信息

批准号：
9357616
负责人：
Richard H Gomer
金额：
$ 27.62万
依托单位：
TEXAS A&M UNIVERSITY
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：
2016-09-23 至 2020-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9357616
关键词：
1-Phosphatidylinositol 3-Kinase Actins Adult Respiratory Distress Syndrome Affinity Agonist Bacteria Binding Sites Biochemical Biochemistry Biological Assay Biological Models CT2584 HMS Cell membrane Cell surface Cells Cellular biology Chemotactic Factors Coupled Cyclic AMP Data Decubitus ulcer Development Diabetic ulcer Dictyostelium Dipeptidyl-Peptidase IV Disease Drug Targeting Eukaryotic Cell Face Foundations G-Protein-Coupled Receptors G-substrate GTP-Binding Protein alpha Subunits, Gs Genes Genetic Genetic Screening Heterotrimeric GTP-Binding Proteins Human Inflammation Knock-out Lead Learning Leukocytes Lipids Lung diseases Mediating Modeling Molecular Molecular Biology Morphogenesis Mus Muscle Cells Nomenclature PAR-2 Receptor Pathway interactions Peptide Hydrolases Play Process Proliferating Property Proteinase-Activated Receptors Proteins Recombinants Reporting Rheumatoid Arthritis Shotguns Signal Transduction Signal Transduction Pathway Techniques Testing Therapeutic Tissues Varicose Ulcer Vascular Proliferation Work cell motility cell type extracellular homologous recombination insight mouse model neutrophil polarized cell polymerization protein purification receptor small molecule tumor

项目摘要

There is good evidence that some cells secrete chemorepellents that cause specific cell types to move away from them. However, much remains to be understood about the identity of the chemorepellents, their receptors, and the mechanisms they use to direct cell motility. We found that proliferating Dictyostelium cells secrete a protein called AprA, and that AprA is an extracellular signal that functions as a chemorepellent. Although AprA has little sequence similarity to mammalian proteins, AprA has predicted structural similarity to the human secreted dipeptidyl protease DPPIV, and shares functional properties with DPPIV. We found that human DPPIV is a chemorepellent for human and mouse neutrophils, and when applied locally, DPPIV can induce neutrophils to leave a tissue in two mouse models of a lung disease called acute respiratory distress syndrome (ARDS), and a mouse model of rheumatoid arthritis. To gain insights into a fundamental mechanism used in morphogenesis, ways to induce neutrophils to leave a tissue, and how one could augment or diminish the effect of a chemorepellent, we propose three specific aims to elucidate the molecular mechanisms used by AprA and DPPIV to cause chemorepulsion. Aim 1 is to identify the AprA receptor, since this plays a key role in the Dictyostelium chemorepulsion mechanism. Our preliminary work has identified a predicted G protein- coupled receptor called GrlH as a possible AprA receptor. We will carefully test this, and if GrlH is not the receptor, we will use several approaches to identify the receptor. Aim 2 is to elucidate the AprA chemorepulsion signal transduction pathway. Our preliminary data indicate that some components of the chemorepulsion mechanism are different from components used by the chemoattraction mechanism that allows Dictyostelium cells to aggregate toward cAMP. We will determine the extent to which the chemorepulsion mechanism uses known components of the chemoattraction mechanism, as well as use the power of unbiased genetic screens in Dictyostelium to identify additional components of the chemorepulsion mechanism. Aim 3 is to test the hypothesis that DPPIV uses a G protein-coupled receptor called PAR2 to induce neutrophil chemorepulsion, and use what we learn about the Dictyostelium chemorepulsion mechanism to determine the similarities and differences between the Dictyostelium and the human neutrophil chemorepulsion mechanisms. Together, this work combining molecular biology, genetics, cell biology, and biochemistry will help to elucidate eukaryotic chemorepulsion mechanisms, and identify potential drug targets that could enhance or inhibit chemorepulsion.

有充分的证据表明，某些细胞分泌引起特定细胞类型的化学物种移动远离他们。但是，关于化学专业人士的身份，他们受体及其用于指导细胞运动的机制。我们发现增殖的dictyostelium细胞分泌一种称为APRA的蛋白质，该APRA是一个充当化学物质的细胞外信号。尽管APRA与哺乳动物蛋白几乎没有序列相似性，但APRA预测了与人分泌的二肽基蛋白酶DPPIV，并与DPPIV共享功能特性。我们发现人类DPPIV是人类和小鼠中性粒细胞的化学物质，当局部应用时，DPPIV可以诱导嗜中性粒细胞在两种称为急性呼吸窘迫的肺部疾病的小鼠模型中留下组织综合征（ARDS）和类风湿关节炎的小鼠模型。洞悉基本机制用于形态发生，诱导嗜中性粒细胞离开组织的方法以及如何增加或减少化学物质的效果，我们提出了三个特定目的，以阐明由 APRA和DPPIV引起化学脉冲。 AIM 1是识别APRA受体，因为这在 dictyostelium化学螺栓机制。我们的初步工作已经确定了一个预测的G蛋白称为GRLH的耦合受体是可能的APRA受体。我们将仔细测试一下，如果GrlH不是受体，我们将使用几种方法来识别受体。目标2是阐明APRA 化学螺栓信号转导途径。我们的初步数据表明化学螺栓机制与化学收集机制使用的组成部分不同，允许Dictyostelium细胞聚集在cAMP上。我们将确定化学螺栓机制使用趋化性机制的已知组成部分，并使用在Dictyostelium中无偏的遗传筛选的力量，以鉴定化学栓塞的其他成分机制。 AIM 3是测试DPPIV使用G蛋白偶联受体称为PAR2的假设诱导嗜中性粒细胞化学乳头，并使用我们了解的有关dictyostelium chemoreorpulsion机制的知识确定dictyostelium和人类中性粒细胞之间的相似性和差异化学螺栓机制。这项工作结合了分子生物学，遗传学，细胞生物学和生物化学将有助于阐明真核化学乳头机制，并确定潜在的药物靶标这可以增强或抑制化学脉冲。