Calicum, MARCKS, and PIP2 regulation of ENaC

ENaC 的钙、MARCKS 和 PIP2 调节

基本信息

批准号：
9245699
负责人：
Abdel Ayube Alli
金额：
$ 13.94万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
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/9245699
关键词：
Actins Adaptor Signaling Protein Alveolar Amiloride Apical Binding Binding Proteins 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 Health Homeostasis Hypertension Hypotension Inherited Injection of therapeutic agent Kidney Knock-out Knockout Mice Laboratories Lead Learning Liquid substance LoxP-flanked allele Lung MARCKS gene 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 Kinase C Proteolysis Public Health Regulation Reporting Risk Factors Role Sodium Sodium Channel Stroke Testing apical membrane aquaporin-2 blood pressure regulation embryonic stem cell epithelial Na+ channel extracellular in vivo inorganic phosphate knock-down knockout animal promoter recombinase recombinase-mediated cassette exchange small hairpin RNA success tissue culture

项目摘要

DESCRIPTION (provided by applicant): 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.

描述（由申请人提供）：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的重要危险因素，包括充血性心力衰竭、中风和终末期肾病。上皮钠通道（ENaC）的组成性激活会导致严重高血压，而 ENaC 的微妙刺激可能会导致原发性高血压。因此，了解 ENaC 的调节对于了解高血压的病因非常重要。我们的实验室是最早证明 ENaC 活性需要磷脂酰肌醇二磷酸 (PIP2) 与 ENaC 亚基氨基末端结构域结合的实验室之一。我们使用远端肾单位钠转运的组织培养模型，结果表明 ENaC 的 PIP2 依赖性调节是由接头蛋白、肉豆蔻酰化富含丙氨酸的 C 激酶底物 (MARCKS) 介导的，该底物结合 PIP2 并增加近端 PIP2 的局部浓度。 ENaC，从而激活 ENaC。 MARCKS 的肉豆蔻酰化氨基末端结构域和基本效应结构域均有助于其在顶端质膜的功能。 MARCKS 的功能可以通过翻译后修饰、与钙/钙调蛋白的关联以及蛋白水解来调节，因此 MARCKS 的调节对于调节 ENaC 也很重要。该项目的目的是展示 MARCKS 如何在体内调节 ENaC，并确定调节肾上皮细胞顶膜 MARCKS 活性的分子机制。