Calicum, MARCKS, and PIP2 regulation of ENaC

ENaC 的钙、MARCKS 和 PIP2 调节

• 批准号: 8700958
• 负责人: Abdel Ayube Alli
• 金额: $ 13.37万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8700958
• 关键词: Actins; Adaptor Signaling Protein; Alveolar; Amiloride; Animals; Apical; Binding; Calcium; Calcium Binding; Calmodulin; Calpain; Carrier Proteins; Cell membrane; Cells; Cleaved cell; Colon; Congestive Heart Failure; Cytoplasm; Cytoskeleton; Disease; Distal; Embryo; End stage renal failure; Epithelial; Epithelial Cells; Essential Hypertension; Etiology; F-Actin; Fluid Balance; Homeostasis; Hypertension; Hypotension; Inherited; Injection of therapeutic agent; Kidney; Knock-out; Knockout Mice; Laboratories; Lead; Learning; Liquid substance; Lung; Mediating; Membrane; Membrane Lipids; Membrane Proteins; Methods; Modeling; Molecular; Mus; Mutation; Names; Nephrons; PKC Phosphorylation Site; Peptide Hydrolases; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phosphorylation; Post-Translational Protein Processing; Probability; Protein Binding; Protein Kinase C; Proteolysis; Public Health; Regulation; Reporting; Risk Factors; Role; Sodium; Sodium Channel; Stroke; System; Testing; apical membrane; aquaporin-2; blood pressure regulation; embryonic stem cell; epithelial Na+ channel; epithelial amiloride-sensitive sodium channel; extracellular; in vivo; inorganic phosphate; knock-down; myristoylated alanine-rich C kinase substrate; promoter; public health relevance; recombinase; small hairpin RNA; success; tissue culture

Abstract Hypertension is a major public health concern because it is an important risk factor for many other diseases including congestive heart failure, stroke, and end-stage renal disease. The constitutive activation of epithelial sodium channels (ENaC) leads to severe hypertension, while subtle stimulation of ENaC may contribute to essential hypertension. Therefore, understanding the regulation of ENaC is important to understand the etiology of hypertension. Our laboratory was among the first to show that ENaC activity requires binding of phosphatidylinositol bis-phosphate (PIP2) to the amino terminal domain of ENaC subunits. We used a tissue culture model of distal nephron sodium transport and we showed that the PIP2 dependent regulation of ENaC is mediated by an adaptor protein, myristoylated alanine-rich C kinase substrate (MARCKS), that binds PIP2 and increases the local concentration of PIP2 near ENaC and, thereby, activates ENaC. The myristoylated amino terminal domain and the basic effector domain of MARCKS both contribute to its function at the apical plasma membrane. The function of MARCKS can be regulated by posttranslational modifications, association with calcium/calmodulin, and proteolysis so that regulation of MARCKS is also important for regulating ENaC. The aims of this project are to show how MARCKS regulates ENaC in vivo and identify the molecular mechanisms that regulate MARCKS activity at the apical membrane of renal epithelial cells.

抽象的 高血压是一个主要的公共卫生问题，因为它是 许多其他疾病，包括充血性心力衰竭，中风和终点肾脏 疾病。上皮钠通道（ENAC）的组成型激活导致 严重的高血压，而微妙的ENAC刺激可能有助于必不可少 高血压。因此，了解ENAC的调节对于 了解高血压的病因。我们的实验室是第一个展示的 ENAC活性需要结合磷脂酰肌醇双磷酸（PIP2）与 ENAC亚基的氨基终端域。我们使用了远端的组织培养模型 肾脏钠转运，我们表明PIP2依赖ENAC的调节 由适配蛋白介导的，富含丙氨酸的C激酶底物介导 （Marcks），结合PIP2并增加了ENAC附近的PIP2的局部浓度 并且，激活ENAC。肉豆蔻酰氨基的氨基终端域和基本 Marcks的效应域都有助于其在顶端等离子体的功能 膜。 Marcks的功能可以通过翻译后调节 修饰，与钙/钙调蛋白的关联和蛋白水解，以便调节 马克克斯对于调节ENAC也很重要。该项目的目的是显示 Marcks如何调节体内ENAC并确定分子机制 调节MARCKS在肾上皮细胞的顶膜上的活性。