RGS14 Regulation of Hormone-sensitive NPT2A-mediated Phosphate Transport

RGS14 激素敏感 NPT2A 介导的磷酸盐转运的调节

基本信息

批准号：
10618970
负责人：
Peter A Friedman
金额：
$ 45.69万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-08-01 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10618970
关键词：
Affect Attenuated Back Binding Biotin Brain C-terminal Cells Chronic Kidney Failure Code Complex Cyclic AMP Data Disease Dissociation Elements Epithelial Cells Equilibrium Exhibits FGFR1 gene G-Protein-Coupled Receptors GTP-Binding Proteins Goals Guanosine Triphosphate Heart Hippocampus Hormones Human Human Cell Line Kidney Kidney Diseases Learning Ligands Ligase Link MAP Kinase Gene MAPK Signaling Pathway Pathway Mediating Metabolism Modeling Molecular Mus Mutation Osteopenia Outcome PDZ protein PTH gene Patients Phosphorylation Phosphotransferases Prevalence Proteins Proteomics Proximal Kidney Tubules Regulation Rodent Role Scaffolding Protein Secondary Hyperparathyroidism Serum Signal Pathway Signal Transduction Site Small Interfering RNA Synaptic plasticity Tertiary Protein Structure Testing Tissues Ventricular Remodeling clinically relevant genome wide association study hormone regulation inorganic phosphate insight knock-down novel response scaffold sodium-hydrogen exchanger regulatory factor uptake

项目摘要

PROJECT SUMMARY: PTH and FGF23 initiate signaling pathways in renal proximal tubule cells that converge on the [NPT2A:NHERF1] complex to inhibit phosphate uptake. Mice lacking the PDZ protein NHERF1 and humans harboring NHERF1 mutations are hypophosphatemic. Important gaps exist in understanding the elements involved in these actions due to unidentified factors. Numerous GWAS studies of patients with chronic kidney disease implicate RGS14, which harbors a PDZ-recognition motif. We propose that RGS14 is a novel regulator of hormone-sensitive phosphate transport, and provide preliminary data to support this idea. RGS14 is scaffold that integrates G protein, MAPK, and Ca++/CaM signaling pathways. Its actions are best understood in rodent brain, where RGS14 suppresses synaptic plasticity and hippocampal-based learning. Nothing is known about RGS14 effects on hormone action or in kidney. Our preliminary findings show that RGS14 suppresses both PTH- and FGF23-regulated phosphate transport. RGS14 persistently attenuates PTH-regulated phosphate transport in primary human proximal tubule cells. RGS14 knock-down by siRNA reverses this action to reveal full PTH activity. RGS14 add-back to cells lacking the protein blocks PTH actions. Human RGS14 contains a C- terminal PDZ ligand (-DSAL) that directly binds NHERF1. Mutations in the PDZ-ligand disrupt RGS14 binding to NHERF1 and interfere with RGS14 regulation of hormone actions. These findings identify RGS14 as an entirely new element regulating hormone action on a vital homeostatic activity, and raise the hypothesis that RGS14 is a novel regulator of hormone-sensitive [NPT2A:NHERF1]-mediated phosphate transport in renal proximal tubule cells. Three Aims will test this premise. AIM 1 will define how RGS14 regulates assembly, disassembly of [NPT2A:NHERF1], its internalization and hormone-sensitive phosphate uptake. AIM 2 will define the locus of RGS14 effects on PTH and FGF23 signaling and the impact of hormone-directed NHERF1 phosphorylation on RGS14 regulation of the [NPT2A:NHERF1] complex. AIM 3: will define how PTH- and FGF23-directed signaling affect RGS14 interactions with NHERF1 and the [NHERF1:NPT2A] complex. These studies will identify novel roles and molecular mechanisms by which RGS14 regulates NPT2A function and hormone-sensitive phosphate transport in kidney as related to kidney disease.

项目摘要：PTH和FGF23在收敛的肾近端小管细胞中启动信号通路在[NPT2A：NHERF1]复合物上以抑制磷酸盐的摄取。缺乏PDZ蛋白NHERF1和携带NHERF1突变的人类是低磷酸化的。重要的差距在理解由于身份不明的因素，这些行动涉及的要素。慢性患者的大量GWAS研究肾脏疾病暗示了RGS14，该疾病具有PDZ-RECKNICTION主题。我们建议RGS14是一部小说激素敏感磷酸盐转运的调节剂，并提供初步数据以支持这一想法。 RGS14 是整合G蛋白，MAPK和CA ++/CAM信号通路的脚手架。最好理解其行为在啮齿动物大脑中，RGS14抑制突触可塑性和基于海马的学习。什么都不知道关于RGS14对激素作用或肾脏的影响。我们的初步发现表明RGS14抑制 PTH-和FGF23调节的磷酸盐转运。 RGS14持续减弱PTH调节的磷酸盐原代人小管细胞中的转运。 sirna击倒RGS14逆转此动作以揭示完整的PTH活动。 RGS14为缺乏蛋白质阻断PTH作用的细胞增添了背部。人RGS14包含一个c- 末端PDZ配体（-dsal）直接结合NHERF1。 PDZ-配体中的突变破坏RGS14结合到NHERF1并干扰RGS14激素作用的调节。这些发现将RGS14确定为全新的元素调节激素对重要的稳态活动的作用，并提出以下假设 RGS14是激素敏感[NPT2A：NHERF1]介导的肾脏近端磷酸转运的新型调节剂小管细胞。三个目标将测试这个前提。 AIM 1将定义RGS14如何调节组装，拆卸 [NPT2A：NHERF1]，其内在化和激素敏感的磷酸盐摄取。 AIM 2将定义 RGS14对PTH和FGF23信号的影响以及激素指导的NHERF1磷酸化对PTH和FGF23信号的影响 RGS14 [NPT2A：NHERF1]复合物的调节。 AIM 3：将定义PTH-和FGF23指导的信号传导影响RGS14与NHERF1和[NHERF1：NPT2A]复合物的相互作用。这些研究将确定新颖 RGS14调节NPT2A功能和激素敏感磷酸盐的作用和分子机制与肾脏疾病有关的肾脏运输。