The role of phosphorylation in regulating the antidiabetic effects of O3FAR-1

磷酸化在调节 O3FAR-1 抗糖尿病作用中的作用

基本信息

批准号：
8495521
负责人：
Nader H Moniri
金额：
$ 40.98万
依托单位：
MERCER UNIVERSITY MACON
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-03-01 至 2017-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8495521
关键词：
Affect Affinity Agonist Amino Acids Anti-Inflammatory Agents Anti-inflammatory Antidiabetic Drugs Arrestins Binding Biomedical Research Blood Glucose Body Weight decreased Cell surface Coupling Cyclic AMP-Dependent Protein Kinases Cytoplasmic Tail Data Dietary Fats Doctor of Pharmacy Doctor of Philosophy Environment Equilibrium Family Funding Mechanisms G Protein-Coupled Receptor Kinase Family G protein coupled receptor kinase G-Protein-Coupled Receptors GTP-Binding Proteins Goals Grant Health Sciences Hormones Human Inflammatory Insulin Insulin Resistance Intestinal Secretions Intestines Knowledge L Cells Laboratories Lead Light MAPK8 gene Mediating Messenger RNA Molecular Nature Neurotransmitters Non-Insulin-Dependent Diabetes Mellitus Omega-3 Fatty Acids Pain Pathway interactions Pharmacy facility Phospholipase C Phosphorylation Phosphotransferases Physiological Play Process Protein Isoforms Protein Kinase C Proteins Proteomics RNA Splicing Receptor Activation Recruitment Activity Regulation Reporting Research Research Activity Research Project Grants Role Scaffolding Protein Second Messenger Systems Signal Pathway Signal Transduction Signaling Protein Site Smell Perception Structure of beta Cell of islet Students Taste Perception Universities Unsaturated Fatty Acids Weight Gain arrestin 2 citrate carrier college glucagon-like peptide glucagon-like peptide 1 guanine nucleotide binding protein human GRK6 protein incretin hormone insight insulin secretion interest macrophage protein activation public health relevance receptor receptor expression response scaffold second messenger undergraduate student

项目摘要

DESCRIPTION (provided by applicant): The omega-3 fatty acid receptor (O3FAR1), also commonly referred to as GPR120, is a G protein-coupled receptor (GPCR) that has been shown to be agonized by long chained unsaturated fatty acids, specifically, those belonging to the omega-3 fatty acid (O3FA) family. This receptor has generated considerable interest due to its ability to stimulate intestinal secretion of the incretin hormone glucagon-like-peptide-1 (GLP-1), which stimulates pancreatic b-cells leading to insulin secretion and subsequently, decreases in blood glucose. In addition to this effect, it has recently been demonstrated that agonism of O3FAR1 leads to profound anti- inflammatory effects via inhibition of the NF-KB and JNK proinflammatory pathways, which when otherwise activated in macrophages, lead to insulin resistance, weight gain, and type 2 diabetes. Our laboratory has revealed that two human O3FAR1 isoforms, O3FAR1-long and short, exist as a consequence of alternative mRNA splicing and our results suggest that these isoforms are differentially regulated by receptor phosphorylation. Our preliminary data also show that G protein-coupled receptor kinase-6 (GRK6) is responsible for homologous (agonist-induced) phosphorylation of O3FAR1 isoforms. Importantly, the antidiabetic effects of O3FAR1 have been shown to be dependent on b-arrestin-2 partner proteins, which are recruited only to GRK-phosphorylated receptors, suggesting that receptor phosphorylation drives O3FAR1 antidiabetic activity. Additionally, our results demonstrate that basal phosphorylation of O3FAR1, which regulates receptor expression and agonist sensitivity, is mediated by protein kinase C (PKC), and that there are differential affects of PKC on the two O3FAR1 isoforms. We propose two specific aims that will provide structural guidance on mechanisms of O3FAR1 activation and signal regulation, and will also provide a better understanding of signaling differences between the two O3FAR1 isoforms. In specific aim one, we will localize the specific sites of GRK and PKC mediated phosphorylation of O3FAR1 isoforms using a proteomic- driven approach. In specific aim two, we will assess the functional significance of these phosphorylation mechanisms with respect to their ability to regulate receptor interactions with b-arrestin-2, activate the Gaq/11- phospholipase C/Ca+2 signaling pathway, secrete GLP-1, and produce anti-inflammatory effects via inhibition of JNK and NF-KB pathways. Collectively, these results will provide structural insight into mechanisms of phospho-regulation of all known O3FAR1 functions. Since research activities at Mercer University's College of Pharmacy and Health Sciences are fully dependent on student integration, this project will allow for incorporation of graduate (PhD), professional (PharmD), and undergraduate students within an established and significant research project, and will greatly strengthen the research environment, consistent with the goals of the AREA funding mechanism.

描述（由申请人提供）：omega-3 脂肪酸受体 (O3FAR1)，通常也称为 GPR120，是一种 G 蛋白偶联受体 (GPCR)，已被证明可被长链不饱和脂肪酸激动，特别是，属于 omega-3 脂肪酸 (O3FA) 家族。该受体因其能够刺激肠道分泌肠促胰岛素激素胰高血糖素样肽-1 (GLP-1) 而引起了极大的兴趣，GLP-1 会刺激胰腺 b 细胞，导致胰岛素分泌，从而降低血糖。除了这种作用之外，最近还证明 O3FAR1 的激动作用通过抑制 NF-KB 和 JNK 促炎途径产生深远的抗炎作用，而这些途径在巨噬细胞中被激活时，会导致胰岛素抵抗、体重增加和体重增加。 2型糖尿病。我们的实验室发现，两种人类 O3FAR1 亚型（O3FAR1 长和短）是由于选择性 mRNA 剪接而存在，我们的结果表明这些亚型受到受体磷酸化的差异调节。我们的初步数据还表明，G 蛋白偶联受体激酶 6 (GRK6) 负责 O3FAR1 亚型的同源（激动剂诱导）磷酸化。重要的是，O3FAR1 的抗糖尿病作用已被证明依赖于 b-arrestin-2 伴侣蛋白，该蛋白仅被招募到 GRK 磷酸化受体，这表明受体磷酸化驱动 O3FAR1 抗糖尿病活性。此外，我们的结果表明，调节受体表达和激动剂敏感性的 O3FAR1 基础磷酸化是由蛋白激酶 C (PKC) 介导的，并且 PKC 对两种 O3FAR1 亚型存在不同的影响。我们提出了两个具体目标，将为 O3FAR1 激活和信号调节机制提供结构指导，并将更好地理解两种 O3FAR1 亚型之间的信号差异。在具体目标一中，我们将使用蛋白质组驱动的方法定位 GRK 和 PKC 介导的 O3FAR1 同工型磷酸化的特定位点。在具体目标二中，我们将评估这些磷酸化机制在调节受体与 b-arrestin-2 相互作用、激活 Gaq/11- 磷脂酶 C/Ca+2 信号通路、分泌 GLP-1 方面的功能意义。，并通过抑制 JNK 和 NF-KB 通路产生抗炎作用。总的来说，这些结果将为所有已知 O3FAR1 功能的磷酸化调节机制提供结构见解。由于美世大学药学与健康科学学院的研究活动完全依赖于学生的整合，因此该项目将允许研究生（博士）、专业人士（药学博士）和本科生纳入一个既定且重要的研究项目，并将极大地促进学生的参与。加强研究环境，与 AREA 资助机制的目标保持一致。