ER-to-cell surface transport and signal regulation of GPCRs

GPCR 的 ER 至细胞表面转运和信号调节

• 批准号: 8067914
• 负责人: GUANGYU WU
• 金额: $ 30.07万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8067914
• 关键词: ADP-Ribosylation Factors; Adrenergic Receptor; Agonist; Arginine; Binding; Binding Proteins; Cell Line; Cell Surface Receptors; Cell membrane; Cell physiology; Cell surface; Cells; Disease; Drug Delivery Systems; Drug Design; Ear; Embryo; Endoplasmic Reticulum; Functional disorder; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; Glioma; Golgi Apparatus; Hormones; Human; Kidney; MAPK3 gene; MEKs; Mediating; Mitogen-Activated Protein Kinases; Modeling; Molecular; Monomeric GTP-Binding Proteins; Neuroblastoma; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Physiological; Protein Isoforms; Regulation; Role; Signal Pathway; Signal Transduction; Specificity; Transport Vesicles; Tryptophan; Vesicle; adrenergic receptor alpha-2b; human disease; in vivo; novel; public health relevance; receptor; response; spatiotemporal; trafficking; trans-Golgi Network

DESCRIPTION (provided by applicant): The spatiotemporal regulation of intracellular trafficking and signaling of G protein-coupled receptors (GPCRs) is a critical aspect of integrated responses of the cell to hormones. Indeed, defective transport and dysfunction of GPCRs are associated with the pathogenesis of many human diseases. Our overall objective is to define the molecular mechanisms underlying the maturation and signal propagation of GPCRs and their roles in modulating cellular responses to hormones and drugs. Under this broad objective, the focus of the current proposal is to elucidate the mechanisms of nascent GPCR export from the endoplasmic reticulum (ER) to the cell surface and GPCR-mediated activation of the mitogen-activated protein kinase pathway in neuroblastoma-glioma NG108 and human embryonic kidney HEK293 cell lines by using alpha2B-adrenergic receptor (alpha2B-AR) as a model GPCR. We have demonstrated that alpha2B-AR export from the ER is modulated by a highly conserved triple arginine (3R) motif. The 3R motif mediates receptor interaction with selective Sec24 isoforms, components of COPII-coated transport vesicles. Our studies have also revealed a novel function for GGAs [monomeric Golgi-localizing, 3-adaptin ear domain homology, ADP ribosylation factor (ARF)-binding proteins]. GGAs associate with alpha2B-AR and are required for alpha2B-AR transport from the trans-Golgi network (TGN) to the plasma membrane. Furthermore, we have identified a novel signaling pathway in which the di-tryptophan motif-mediated, agonist-dependent interaction of alpha2B-AR with the small GTPase ARF1 dictates the activation of the conventional Raf1-MEK-ERK1/2 cascade by the receptor. The Specific Aims are: 1) to elucidate the mechanism of COPII vesicle-mediated alpha2B-AR export from the ER, 2) to determine the function of GGAs in alpha2B-AR transport from the TGN to the cell surface, and 3) to define the function and mechanism of alpha2B-AR- and ARF1-mediated activation of the Raf1-MEK-ERK1/2 pathway. Overall, these studies will reveal novel molecular mechanisms underlying export trafficking and signal regulation of GPCRs. The information generated from these studies may open new directions for designing drugs to treat diseases involving abnormal trafficking and functioning of GPCRs. PUBLIC HEALTH RELEVANCE: This proposal will study the intracellular trafficking and functional regulation of G protein-coupled receptors. These receptors regulate a variety of cell functions under physiological and pathological conditions and are the targets for drugs to treat many diseases. The successful completion of these studies will open a new direction for designing drugs to treat human diseases involving abnormal trafficking and functioning of G protein-coupled receptors.

描述（由申请人提供）：G蛋白偶联受体（GPCR）的细胞内运输和信号传导的时空调节是细胞对激素综合响应的关键方面。实际上，GPCR的有缺陷的运输和功能障碍与许多人类疾病的发病机理有关。我们的总体目标是定义GPCR成熟和信号传播的基础机制及其在调节细胞对激素和药物的作用中的作用。在这个广泛的目标下，目前的提案的重点是阐明新生GPCR从内质网（ER）出口到细胞表面到细胞表面，并使用神经母细胞瘤ngglagrastoma ngy-embryon-embryon-heky Hek293细胞蛋白蛋白酶途径的GPCR介导的促分裂原激活蛋白激酶途径的激活，该蛋白质激酶途径使用ALHEM-HUMEN-HERMEN-HEK293 CILLPHANEK 293。 （alpha2b-ar）作为型号GPCR。我们已经证明，来自ER的α2B-AR导出是由高度保守的三重精氨酸（3R）基序调节的。 3R基序与选择性SEC24同工型（Copii涂层囊泡的成分）介导受体相互作用。我们的研究还揭示了GGAS [单体高尔基体定位，3-适应性耳朵域同源性，ADP核糖基化因子（ARF）结合蛋白]的新功能。 GGA与alpha2b-ar相关，是从反式高尔基网络（TGN）到质膜的α2B-AR运输所必需的。此外，我们已经确定了一种新型的信号通路，其中二键trifan序列介导的，依赖性依赖性的Alpha2b-AR与小GTPase ARF1的激动剂依赖性相互作用决定了受体传统的RAF1-MEK-ERK1/2级联的激活。具体目的是：1）阐明从ER的Copi囊泡介导的Alpha2b-AR导出的机制，2）确定GGA在Alpha2b-AR在TGN中的运输功能，以及定义Alpha2b-AR-AR-和ARF1介导的Alpha2b-AR-AR-AR-AR-AR-AR-AR-AR-AR FATERACTACTIAN ARFAID EXTICTACTION AIRKINACTION ALPHA2B-AR-AR-AR-AR-AR-AR-AR-AR-ARF的功能和机制。总体而言，这些研究将揭示出出口运输和GPCR的信号调节的新分子机制。从这些研究中产生的信息可能会为设计用于治疗涉及异常贩运和GPCR功能的疾病的新方向。 公共卫生相关性：该提案将研究G蛋白偶联受体的细胞内贩运和功能调节。这些受体在生理和病理条件下调节各种细胞功能，并且是治疗许多疾病的药物的靶标。这些研究的成功完成将为设计药物治疗涉及异常运输和G蛋白偶联受体功能的人类疾病的新方向。