Gbeta5-R7 Complex in Signaling and Hormone Secretion

Gbeta5-R7 复合物在信号传导和激素分泌中的作用

基本信息

批准号：
9137158
负责人：
Vladlen Z Slepak
金额：
$ 1.37万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-04-01 至 2019-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9137158
关键词：
Agonist Animals Area Arrestins Beta Cell Biochemical Pathway Biological Assay Body Weight Cell Line Cell membrane Cells Complex Data Development Diabetes Mellitus Diagnostic Disease Drug Regulations Drug effect disorder Employee Strikes Endocrine Glands Etiology Family Foundations Future G Protein-Coupled Receptor Signaling GTP-Binding Protein Regulators GTP-Binding Proteins Gene Expression Gene Expression Profile Gene Expression Regulation Gene Proteins Glucose Growth Guanosine Triphosphate Phosphohydrolases Health Hormones In Situ Hybridization Insulin Investigation Ion Channel Islets of Langerhans Knock-out Knockout Mice Laboratories Locomotion Measures Mediating Metabolic Diseases Metabolism Modeling Molecular Mus Muscarinic M3 Receptor Muscarinics Nerve Nervous system structure Neurons Nutrient Obesity Pancreas Pathway interactions Phosphotransferases Physiological Process Protein Family Proteins RGS Proteins RNA Reading Receptor Signaling Regulation Research Reverse Transcriptase Polymerase Chain Reaction Role Secretory Cell Signal Transduction Stress Structure of beta Cell of islet Testing Tissues Transplantation Weight maintenance regimen glucose metabolism hormone regulation in vitro Assay inhibitor/antagonist insight insulin secretion insulinoma islet knockout gene member neurotransmitter release next generation sequencing novel programs protein complex protein expression protein protein interaction receptor coupling research study response sensory system stem

项目摘要

DESCRIPTION (provided by applicant): Complexes of the G protein βsubunit Gβ5 with the R7 family of RGS proteins serve as GAPs for Gi family and are involved in many physiological functions. Both Gβ5 and R7 proteins were originally found in the nervous system, but recently detected in some other tissues, notably endocrine glands. The current study concentrates on the role of Gβ5-R7 in pancreatic β cells and advances an original line of research developed in this laboratory: regulation of M3 muscarinic receptor (M3R) by Gβ5-R7. The most recent study identified a novel pathway where Gβ5-R7 can potentiate M3R-induced Ca2+ influx across the plasma membrane. This effect on Ca2+ flux is consistent with the higher level of insulin secretion in the presence of Gβ5-R7. The positive effect is novel and exciting because RGS proteins are thought to be negative regulators of G protein signaling. Another puzzling detail is that M3R is a Gq-coupled receptor, and Gβ5-R7 members do not have GAP activity for Gq. The project will pursue three well-integrated aims. To determine specific β cell signaling mechanisms sensitive to Gβ5-R7, Aim 1 will target members of the M3R-to-insulin pathway with pharmacologic inhibitors or gene knockout and knockdown. Studies will be performed in pancreatic islets from WT and G 5 knockout mice and insulinoma cell line Min6. Experiments will measure insulin secretion, [Ca I] and other signaling responses to 2+ M3R agonists. Aim 2 will generate and analyze mice with β cell-specific knockout of Gβ5. Primary islets from these mice will be examined by signaling and secretion assays in vitro and long-term functionality of these islets will be studied after their intraocular transplantation into mice with induced diabete. Aim 3 will determine the effect of Gβ5-R7 complex on gene expression using a combination of RT-PCR, in situ hybridization and next generation sequencing of pancreatic islet RNA from Gβ5 KO mice. These studies will have a strong impact on understanding pancreatic β cell signaling, insulin secretion and adaptation to stress. The new mechanistic insights will provide a sustained flow of ideas for the broad area of GPCR signaling, regulation of hormone release and etiology such of metabolic disorders as diabetes and obesity.

描述（由适用提供）：G蛋白βSubunitGβ5与R7的RGS蛋白质的复合物是GI家族的间隙，并参与了许多物理功能。 Gβ5和R7蛋白最初都在神经系统中发现，但最近在其他一些组织中检测到，尤其是内分泌网格。当前的研究集中于Gβ5-R7在胰腺β细胞中的作用，并推进了该实验室中开发的原始研究：通过Gβ5-R7调节M3毒蕈碱受体（M3R）。最新的研究确定了一种新的途径，其中Gβ5-R7可以潜在M3R诱导的Ca2+影响整个质膜。在Gβ5-R7存在下，这种对Ca2+通量的影响与较高的胰岛素分泌水平一致。积极作用是新颖而令人兴奋的，因为RGS蛋白被认为是G蛋白信号传导的负调节剂。另一个难题的细节是M3R是GQ耦合受体，而Gβ5-R7成员对GQ没有间隙活性。该项目将追求三个整合的目标。为了确定对Gβ5-R7敏感的特定β细胞信号传导机制，AIM 1将用药物抑制剂或基因敲除和敲除靶向M3R到胰岛素途径的成员。研究将在WT和G 5基因敲除小鼠和胰岛素瘤细胞系MIN6的胰岛进行研究。实验将测量胰岛素分泌，[CA I]以及对2+ M3R激动剂的其他信号反应。 AIM 2将用Gβ5的β细胞特异性敲除产生和分析小鼠。这些小鼠的主要问题将通过体外的信号传导和分泌测定来检查，这些胰岛的长期功能将在其眼内移植到患有诱导的糖尿病的小鼠中后进行研究。 AIM 3将使用RT-PCR，原位杂交和从Gβ5KO小鼠的胰岛RNA进行原位杂交和下一代测序的组合来确定Gβ5-R7复合物对基因表达的影响。这些研究将对理解胰腺β细胞信号传导，胰岛素分泌和对应激的适应性产生强烈的影响。新的机械洞察力将为GPCR信号的广泛领域提供持续的思想，释放马酮的调节和病因，例如糖尿病和肥胖症等代谢性疾病。