Investigation of Adhesion GPCR and Ric-8 protein control of heterotrimeric G proteins

异三聚体 G 蛋白粘附 GPCR 和 Ric-8 蛋白控制的研究

基本信息

批准号：
10622696
负责人：
Gregory Gordon Tall
金额：
$ 19.73万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-04-01 至 2028-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10622696
关键词：
ADGR1 gene Adhesions Agonist Biochemical Biological Blood Blood Platelets Cell Adhesion Cell membrane Cells Cellular biology Complex Disease Dissociation Drosophila genus Elements Event Extracellular Matrix Family Family member G-Protein-Coupled Receptors GTP-Binding Protein alpha Subunits GTP-Binding Proteins Genetic Goals Guanine Nucleotides Heterotrimeric GTP-Binding Proteins Investigation Ligands Molecular Chaperones Protein Biochemistry Proteins Series Signal Transduction Specificity Structure Substrate Specificity Sum System Techniques Transmembrane Domain Work cell type experimental study extracellular in vivo member mouse model protein complex receptor response

ADGR1 gene Adhesions Agonist Biochemical Biological Blood Blood Platelets Cell Adhesion Cell membrane Cells Cellular biology Complex Disease Dissociation Drosophila genus Elements Event Extracellular Matrix Family Family member G-Protein-Coupled Receptors GTP-Binding Protein alpha Subunits GTP-Binding Proteins Genetic Goals Guanine Nucleotides Heterotrimeric GTP-Binding Proteins Investigation Ligands Molecular Chaperones Protein Biochemistry Proteins Series Signal Transduction Specificity Structure Substrate Specificity Sum System Techniques Transmembrane Domain Work cell type experimental study extracellular in vivo member mouse model protein complex receptor response

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项目摘要

Project Summary: This MIRA proposal will combine work from our longstanding projects on the structure and function of adhesion G protein coupled receptors (or Family B2 GPCRs) and the molecular chaperones for G protein alpha subunits, Ric-8 proteins. Adhesion GPCRs are a large, 33-member family of receptors that transduce signals from cell to cell or cell to extracellular matrix adhesion events across the cell membrane to awaiting G proteins in order to elicit responses within the cell. Our work has advanced a mechanism for adhesion GPCR activation in which the extracellular adhesion domains become anchored to protein ligands and the cell that contains the GPCR or seven transmembrane domain (7TM) moves, by any number of means, in relation to this fixed anchor to dissociate the two halves of the adhesion GPCR. This dissociation event reveals a previously hidden tethered agonist of the GPCR/7TM domain that self-activates the receptor. This mode of activation seems common to most members of the adhesion GPCR family, but alternative modes of adhesion GPCR activation have also come to the fore of the field. Our goal in this proposal is to expand upon our mechanistic and structural work to decipher varied adhesion GPCR activation modes using biochemical, cell biological, and in vivo approaches, including work with two mouse models newly created for this proposal. We will focus on adhesion GPCRs that are present in cells that circulate in the blood, for example ADGRG1/GPR56 on platelets, as well as additional ADGRG subfamily members present on other circulating cell types. Circulating cells offer an advantage for interrogating adhesion GPCR action because the shear force component that dissociates the two fragments of the receptors, for the purpose of tethered-agonist-activation, is readily tractable. The sum of our work will be to distinguish tethered agonist -dependent and -independent modes of adhesion GPCR activation, which we argue is perhaps the most important contemporary question in the adhesion GPCR field. In parallel, we have assigned the function of Ric-8A and Ric-8B proteins as molecular chaperones that are required to collectively fold all G protein alpha subunits. This is a mature project for our lab, yet we have made recent breakthroughs in solving the structures of Ric-8/G protein guanine nucleotide-free complexes. We present preliminary evidence of a new Ric-8/G protein complex structure that will enable us to finally tackle a major outstanding question; What are the structural elements of mammalian Ric-8A and Ric-8B that define their specificities for different G protein subtypes? Combined with analysis of the single copy of an ancestral Ric-8 (Drosophila Ric-8) that seemingly crosses the lines and appears to fold all G protein subtypes, our work will provide new understanding of the substrate specificity rules, thereby providing a rationale for potentially targeting the Ric-8 chaperone system in contexts of G protein-driven disease.

项目摘要：该MIRA提案将结合我们长期以来在结构上的项目的工作 G蛋白耦合受体（或家族B2 GPCR）和G的分子伴侣的粘附G蛋白偶联受体的功能蛋白α亚基，RIC-8蛋白。粘附GPCR是一个由33个成员的受体家族，从细胞到细胞或细胞到整个细胞膜跨细胞外基质粘附事件的转导信号等待G蛋白以引起细胞内的反应。我们的工作提高了粘附的机制 GPCR激活细胞外粘附域锚定在蛋白质配体和细胞上其中包含GPCR或七个跨膜域（7TM）移动，任何均值该固定锚以分离粘附GPCR的两半。此解离事件揭示了以前的自我激活受体的GPCR/7TM结构域的隐藏的束缚激动剂。这种激活方式 GPCR家族的大多数成员似乎很常见，但是GPCR的替代模式激活也已经浮出水面。我们在此提案中的目标是扩展我们的机械以及使用生化，细胞生物学和体内方法，包括与新为该建议新创建的两种鼠标模型一起工作。我们将重点关注在血液中循环的细胞中存在的粘附GPCR，例如血小板上的ADGRG1/GPR56，以及其他循环细胞类型上存在的其他ADGRG亚家族成员。循环细胞提供询问粘附GPCR作用的优势，因为分离的剪切力成分为束缚 - 激活激活的目的，受体的两个片段很容易拖延。总和我们的工作将是区分绑扎激动剂 - 依赖性和 - 独立的粘附模式GPCR 激活，我们认为这也许是GPCR粘附领域中最重要的当代问题。同时，我们将RIC-8A和RIC-8B蛋白的功能分配为分子伴侣需要共同折叠所有G蛋白α亚基。这是我们实验室的一个成熟项目，但我们已经做了在解决RIC-8/G蛋白鸟嘌呤无核苷酸复合物的结构方面的最新突破。我们当前新的RIC-8/G蛋白复合结构的初步证据，该结构将使我们最终解决主要的杰出问题；哺乳动物RIC-8A和RIC-8B的结构元素是什么定义它们的不同G蛋白亚型的特异性？结合对祖先RIC-8的单个副本的分析（果蝇RIC-8）看似越过线条并似乎折叠了所有G蛋白质亚型，我们的工作将会提供对底物特异性规则的新了解，从而提供了潜在目标的理由 RIC-8伴侣系统在G蛋白驱动疾病的情况下。