Calcium sensing receptor and scaffolds

钙敏感受体和支架

基本信息

批准号：
7609169
负责人：
GERDA E BREITWIESER
金额：
$ 28.74万
依托单位：
GEISINGER CLINIC
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-04-01 至 2011-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7609169
关键词：
Acids Acute Address Affect Affinity Agonist Amino Acids Arrestins Attenuated Attenuation of GPCR Signaling Pathway Binding Biochemical Calcium Calcium-Sensing Receptors Cell Proliferation Cell physiology Cells Clinical Complex Cytoskeletal Proteins Data Disease Dissection Endoplasmic Reticulum Degradation Pathway Epidermal Growth Factor Receptor Equilibrium Excretory function Exhibits Human Image Intervention Kidney Kidney Diseases Link MAP Kinase Gene Maintenance Malignant Neoplasms Mediating Metabolism Molecular Mutation Osteoporosis Parathyroid gland Pathway interactions Phosphorylation Point Mutation Polyamines Receptor Activation Receptor Gene Receptor Signaling Research Personnel Role Scaffolding Protein Serum Signal Pathway Signal Transduction Site Small Interfering RNA Specificity Testing Transact Transactivation Ubiquitination Yeasts arrestin 1 arrestin 2 extracellular filamin human disease multicatalytic endopeptidase complex mutant novel overexpression parathyroid hormone-related protein programs protein expression receptor expression receptor function receptor-mediated signaling research study response scaffold trafficking ubiquitin-protein ligase yeast two hybrid system

项目摘要

DESCRIPTION (provided by applicant): The calcium sensing receptor (CaR) transduces local changes in extracellular calcium and metabolites (anrtino acids, polyamines) into intracellular signals, which include acute alterations in cell metabolism and secretion, and long term changes in cell proliferation and differentiation. CaR is critical to maintenance of systemic calcium levels, by controlling parathyroid PTH secretion and the balance of renal calcium excretion/resorption. Cell-specific variability in CaR signaling may in part be due to interaction(s) of CaR with scaffold proteins and the formation of cell-specific signaling complexes. The cytoskeletal protein filamin A is a scaffold for CaR, required for CaR-mediated activation of MARK signaling, and slowing CaR degradation. Preliminary data suggests CaR interactions with arrestins-1 and -2 modulate intracellular calcium responses and MARK signaling. To understand how protein scaffolds regulate CaR-mediated signaling, we will test the following hypotheses: (1) Does state-dependent arrestin-1 binding regulate CaR responsiveness? (2) Is CaR-mediated MARK signaling organized by filamin A and arrestin-2, and does the signaling pathway include transactivation of the EGF receptor? (3) Does filamin A act as a molecular escort to stabilize cellular CaR levels by protecting CaR from proteasome-mediated degradation? We will combine biochemical approaches with intracellular calcium and/or confocal imaging, using human CaR and mutant and deletion constructs. The proposed experiments will increase our understanding of the role of the protein scaffolds arrestin-1 and -2 and filamin A in enhancing the specificity of CaR signaling. More than 40 mutations in human CaR have been linked to disease, revolutionizing the clinical dissection of parathyroidisms. Allosteric modulators of CaR have clinical utility for treatment of primary hyper- and hypo- parathyroidism, secondary changes in parathyroid function resulting from renal disease, and osteoporosis. CaR stimulates cell proliferation as well as PTHrP secretion, suggesting role for CaR in potentiating the pathophysiological consequences of malignancies. Dysregulation of CaR expression and/or acute or long term signaling may, in part, be the result of altered interactions with scaffold proteins which serve to enhance CaR signaling specificity and to regulate CaR stability. Understand the role of scaffolds in CaR function may provide novel, specific sites for pharmacological intervention in treatment of calcium handling diseases.

描述（申请人提供）：钙敏感受体（CaR）将细胞外钙和代谢物（氨基酸、多胺）的局部变化转导为细胞内信号，包括细胞代谢和分泌的急性改变，以及细胞增殖和代谢的长期变化。差异化。 CaR 通过控制甲状旁腺 PTH 分泌和肾钙排泄/再吸收的平衡，对于维持全身钙水平至关重要。 CaR 信号传导的细胞特异性变异性可能部分归因于 CaR 与支架蛋白的相互作用以及细胞特异性信号传导复合物的形成。细胞骨架蛋白细丝蛋白 A 是 CaR 的支架，是 CaR 介导的 MARK 信号传导激活和减缓 CaR 降解所必需的。初步数据表明 CaR 与抑制蛋白-1 和 -2 的相互作用可调节细胞内钙反应和 MARK 信号传导。为了了解蛋白质支架如何调节 CaR 介导的信号传导，我们将测试以下假设：（1）状态依赖性抑制蛋白-1 结合是否调节 CaR 反应？ (2) CaR 介导的 MARK 信号传导是否由细丝蛋白 A 和抑制蛋白-2 组织，信号通路是否包括 EGF 受体的反式激活？ (3) 细丝蛋白 A 是否可以充当分子护卫者，通过保护 CaR 免受蛋白酶体介导的降解来稳定细胞 CaR 水平？我们将使用人类 CaR 以及突变和缺失构建体，将生化方法与细胞内钙和/或共聚焦成像相结合。拟议的实验将加深我们对蛋白质支架抑制蛋白-1和-2以及纤丝蛋白A在增强CaR信号传导特异性方面的作用的理解。人类 CaR 中有 40 多种突变与疾病有关，彻底改变了甲状旁腺功能的临床分析。 CaR 变构调节剂具有治疗原发性甲状旁腺功能亢进和甲状旁腺功能减退症、肾病引起的甲状旁腺功能继发性变化以及骨质疏松症的临床实用性。 CaR 刺激细胞增殖以及 PTHrP 分泌，表明 CaR 在增强恶性肿瘤的病理生理学后果中发挥作用。 CaR 表达和/或急性或长期信号传导失调可能部分是由于与支架蛋白相互作用改变的结果，支架蛋白有助于增强 CaR 信号传导特异性并调节 CaR 稳定性。了解支架在 CaR 功能中的作用可能为治疗钙代谢疾病的药物干预提供新的、特定的位点。