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：
8864017
负责人：
Vladlen Z Slepak
金额：
$ 42.21万
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/8864017
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 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 public health relevance 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（由申请人提供）：G蛋白β亚基Gβ5与RGS蛋白R7家族的复合物充当Gi家族的GAP并且参与许多生理功能Gβ5和R7蛋白最初都在神经系统中发现，但最近发现。在一些其他组织中检测到，特别是内分泌腺。当前的研究集中于 Gβ5-R7 在胰腺 β 细胞中的作用，并推进了本实验室开发的原创研究：M3 的调节。最近的研究发现，Gβ5-R7 可以增强 M3R 诱导的 Ca2+ 跨质膜流入，这种对 Ca2+ 通量的影响与胰岛素分泌水平较高是一致的。 Gβ5-R7 的存在带来的积极影响是新颖且令人兴奋的，因为 RGS 蛋白被认为是 G 蛋白信号传导的负调节因子。 Gq 偶联受体和 Gβ5-R7 成员不具有 Gq 的 GAP 活性。为了确定对 Gβ5-R7 敏感的特定 β 细胞信号传导机制，目标 1 将针对 M3R- 成员。将在 WT 和 G 5 敲除小鼠的胰岛以及胰岛素瘤细胞系 Min6 中进行研究。 Aim 2 将生成并分析具有 β 细胞特异性敲除 Gβ5 的小鼠的胰岛素分泌、[Ca I] 和其他信号传导反应，并通过体外和长期的信号传导和分泌测定来检查这些小鼠的原代胰岛。将这些胰岛移植到患有诱导糖尿病的小鼠体内后，将研究这些胰岛的长期功能。目标 3 将使用 RT-PCR 组合原位确定 Gβ5-R7 复合物对基因表达的影响。 Gβ5 KO 小鼠胰岛 RNA 的杂交和下一代测序将对理解胰腺 β 细胞信号传导、胰岛素分泌和应激适应产生重大影响。新的机制见解将为广泛领域提供持续的思路。 GPCR 信号传导、激素释放调节以及糖尿病和肥胖等代谢性疾病等病因学。