Regulation of NKCC2 and renal NaCl transport by protein-protein interactions

通过蛋白质-蛋白质相互作用调节 NKCC2 和肾脏 NaCl 转运

基本信息

批准号：
10585141
负责人：
Pablo A. Ortiz
金额：
$ 60.22万
依托单位：
WAYNE STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-01-20 至 2026-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10585141
关键词：
Acetazolamide Affect Alstrom syndrome Animal Model Apical Binding Biological Biology Biotinylation Blood Pressure Bumetanide Carrier Proteins Cells Complex Data Distal Duct (organ) structure Endocytosis Epithelium Excretory function Feedback Focal and Segmental Glomerulosclerosis Functional disorder Gene Deletion Genes Genetic Goals Homeostasis Human Hypertension Image Ions Kidney Kidney Diseases Knock-out Limb structure Macula densa Mass Spectrum Analysis Measures Mediating Membrane Microscopy Molecular Monitor Mutation Natriuresis Nephrons Non-Insulin-Dependent Diabetes Mellitus Obesity Physiology Proteins Proteomics Rattus Recycling Regional Perfusion Regulation Renal function Retrieval Role Single Nucleotide Polymorphism Sodium Chloride Structure of ascending limb of Henle&apos s loop Surface Thick absorption alpha Actinin apical membrane benzamil blood pressure regulation epithelial Na+ channel human disease human model novel patch clamp podocyte prevent protein protein interaction renal damage salt balance salt sensitive hypertension symporter thiazide

项目摘要

Abstract In the kidney, the thick ascending limb (TAL) of the loop of Henle is critical for NaCl homeostasis and blood pressure regulation. In humans and animal models of salt-sensitive hypertension, NaCl absorption is abnormally increased in the TAL, where NaCl absorption depends on the renal transporter NKCC2, an apical Na+/K+/2Cl- co-transporter. We showed that the presence of NKCC2 at the TAL apical membrane controls NaCl absorption in this epithelium. The molecular mechanisms that control apical membrane NKCC2 levels involve endocytosis, recycling and exocytic insertion. Inhibition of endocytic retrieval causes NKCC2 accumulation at the membrane and increased NaCl absorption. Any gene or protein affecting NKCC2 endocytosis could potentially influence NKCC2 activity and renal salt transport but only few proteins are known to bind NKCC2. Using a targeted proteomics screen, we identified ALMS1 (Alström Syndrome 1) and ACTN4 (alpha-actinin 4) as interacting partners of NKCC2. We also found that ALMS1 and ACTN4 interact with each other, raising the possibility that these proteins form a complex. Single nucleotide polymorphisms in ALMS1 and ACTN4 are associated with hypertension and decreased kidney function. We found that ALMS1 knockout rats have higher surface NKCC2 and high blood pressure. We found that ACTN4, a protein involved in podocyte biology, is also expressed throughout the nephron, including the TAL. The roles of ALMS1 and ACTN4 in renal NaCl handling by the TAL and their role in blood pressure regulation are unknown. We hypothesize that ALMS1 controls surface NKCC2 levels and NKCC2-mediated NaCl absorption by binding the carboxyl-terminus of NKCC2 and ACTN4 to mediate NKCC2 endocytosis from the apical membrane. A decrease in ALMS1 or ACTN4 expression in the TAL increases surface NKCC2, NKCC2-mediated NaCl reabsorption, tubulo-glomerular feedback (TGF) sensitivity and leads to salt-sensitive hypertension. Our long-term goal is to increase our understanding of the role of ALMS1 and ACTN4 in kidney NaCl transport.

抽象的在肾脏中，亨尔环路的较长的升高（tal）对于NaCl稳态和血液至关重要压力调节。在人类和盐敏感高血压的动物模型中，NaCl滥用症异常是在TAL中增加了NaCl滥用依赖肾脏转运蛋白NKCC2，一个顶端Na+/K+/2cl- 共同转运者。我们表明，在TAL顶部膜上存在NKCC2控制NaCl滥用在这个上皮中。控制顶膜NKCC2水平的分子机制涉及内吞作用，回收和外旋转插入。抑制内吞检测会导致NKCC2在膜上积累并增加了NACL滥用。任何影响NKCC2内吞作用的基因或蛋白质都可能影响 NKCC2活性和肾脏盐的转运，但只有很少的蛋白质结合NKCC2。使用目标蛋白质组学筛选，我们将ALMS1（Alström综合征1）和ACTN4（α-肌动蛋白4）鉴定为相互作用 NKCC2的合作伙伴。我们还发现，ALMS1和ACTN4相互互动，提高了可能性这些蛋白质形成复合物。 ALMS1和ACTN4中的单个核苷酸多态性与高血压和改善的肾功能。我们发现ALMS1敲除大鼠具有较高的表面NKCC2 和高血压。我们发现ACTN4（一种参与足细胞生物学的蛋白质）也被表达在整个肾单位，包括TAL。 ALMS1和ACTN4在TAL的肾脏NaCl处理中的作用它们在血压调节中的作用尚不清楚。我们假设ALMS1控制表面NKCC2 通过结合NKCC2和ACTN4的羧基末端进行介导的水平和NKCC2介导的NaCl滥用根尖膜的NKCC2内吞作用。 TAL中ALMS1或ACTN4表达的降低增加表面NKCC2，NKCC2介导的NaCl重吸收，tubulo-glomerular反馈（TGF）敏感性并导致对盐敏感的高血压。我们的长期目标是提高我们对肾脏NACL运输中的ALMS1和ACTN4。