Regulation of lysosomal potassium channels

溶酶体钾通道的调节

基本信息

批准号：
9901594
负责人：
Dejian Ren
金额：
$ 32.58万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9901594
关键词：
3-Dimensional Alzheimer&apos s Disease Autophagocytosis Autophagosome Bathing Biophysics Calcium Cations Cell membrane Cell physiology Chloride Ion Closure by clamp Complex Cytosol Digestion Disease Exocytosis FRAP1 gene Face Functional disorder Genetic Variation Goals Growth Factor Heterogeneity Hormone secretion Human Insulin Ion Channel Ions Kinetics Knockout Mice Link Lumen of the Lysosome Lysosomal Storage Diseases Lysosomes Malignant Neoplasms Measures Mediating Membrane Membrane Potentials Modeling Molecular Molecular Genetics Muscle Contraction Nerve Degeneration Neurodegenerative Disorders Neurons Organelles Parkinson Disease Pathologic Permeability Phosphotransferases Physiological Physiology Play Potassium Potassium Channel Predisposition Principal Investigator Property Protein Chemistry Protein Kinase Proteins Proto-Oncogene Proteins c-akt Proton Pump Recycling Regulation Research Role Serum Shapes Signal Transduction Structure System Testing Time Tissues VDAC1 gene Vesicle base experimental study genome wide association study genome-wide knockout animal mouse model novel patch clamp potassium ion programs recruit repaired small molecule vacuolar H+-ATPase voltage

项目摘要

Program Director/Principal Investigator (Last, First, Middle): Ren, Dejian The overall goal of the proposed research is to understand the function and the regulation of potassium ion channels to the function of lysosomes. Potassium is the most abundant intracellular ion that faces both plasma membrane and organelle membrane. Plasma membranes are highly permeable to potassium. More than 80 potassium channels have now been discovered to mediate such plasma membrane potassium permeability. In contrast, how potassium passes intracellular organelles such as lysosomes is much less understood. Lysosomes play fundamental roles in cellular clearance, digestion, recycling, exocytosis and membrane repair. Because of high concentration of calcium in the lumen, lysosomes are also calcium stores from which calcium is released into cytosol to shape cytosolic calcium kinetics and to regulate muscle contraction and hormone secretion. Lysosomal dysfunction has been linked to pathophysiological conditions such as lysosomal storage diseases, cancer and neurodegeneration. Therefore understanding how lysosomal membrane mediates ionic permeability is important to our understanding of the organelle’s physiology function. We recently discovered a novel protein TMEM175 that forms a potassium-selective channel in lysosomal membrane. Genetic variation in human TMEM175 is also implicated in Parkinson’s disease. We propose three specific aims to expand our preliminary findings. In Aim 1, we will use patch clamp recordings to compare wild-type and TMEM175 knockout animals and will test whether there are other major lysosomal potassium channels in addition to TMEM175. Unlike those of plasma membrane channels, the functions of lysosomal potassium channels are largely unknown. In Aim 2, we will use the TMEM175 knockout mouse model to test the hypothesis that potassium channels regulate the normal working of lysosomes including organelle membrane potential regulation, luminal acidification, vesicle fusion and autophagy. In Aim 3, we will test whether TMEM175, like many other potassium channels on plasma membrane, is regulated by protein kinases. Using protein chemistry experiments, we will also determine the structural requirements for such regulation. Because of the fundamental function of lysosomes, the studies will reveal how lysosomal potassium channels contribute to the organelle’s function under physiological and pathological conditions. OMB No. 0925-0001/0002 (Rev. 01/18 Approved Through 03/31/2020) Page

计划总监/首席研究员（最后，第一，中间）：Ren，Dejian 拟议研究的总体目标是了解钾离子的功能和调节通道的溶酶体功能。钾是面对两个等离子体的最丰富的细胞内离子膜和细胞器膜。质膜高度可渗透到钾。超过80 现在已经发现钾通道介导这种质膜钾的渗透性。在对比，钾如何通过细胞内细胞器（如溶酶体）的了解远不止理解。溶酶体在细胞清除，消化，回收，胞吐和膜修复中起着基本作用。由于管腔中的钙浓度高，溶酶体也是钙储存被释放到细胞质中以塑造胞质钙动力学并调节肌肉收缩和骑马分泌。溶酶体功能障碍已与病理生理状况（例如溶酶体储存）有关疾病，癌症和神经退行性。因此了解溶酶体膜如何介导离子渗透性对我们对细胞器的生理功能的理解很重要。我们最近发现了一个新型蛋白质TMEM175在溶酶体膜中形成钾选择通道。遗传变异在人类TMEM175中也在帕金森氏病中实施。我们提出了三个特定的目标，以扩大我们的初步发现。在AIM 1中，我们将使用斑块夹录音比较野生型和TMEM175 敲除动物，并将测试除了还有其他主要的溶酶体钾通道 TMEM175。与质膜通道不同，溶酶体钾通道的功能是在很大程度上未知。在AIM 2中，我们将使用TMEM175敲除鼠标模型来检验以下假设。钾通道调节包括细胞器膜在内的溶酶体的正常工作调节，腔酸化，囊泡融合和自噬。在AIM 3中，我们将测试TMEM175是否喜欢质膜上的许多其他钾通道受蛋白激酶调节。使用蛋白质化学实验，我们还将确定这种调节的结构要求。因为溶酶体的基本功能，研究将揭示溶酶体钾通道如何有助于在生理和病理条件下，Organelle的功能。 OMB编号0925-0001/0002（修订版01/18通过03/31/2020批准）页面