Regulation of the Na/K Pump by RNA Editing

RNA 编辑对 Na/K 泵的调节

基本信息

批准号：
7885009
负责人：
JOSHUA J.C. ROSENTHAL
金额：
$ 29.71万
依托单位：
UNIVERSITY OF PUERTO RICO MED SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-08-01 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7885009
关键词：
ATP phosphohydrolase Abbreviations Action Potentials Adenosine Affect Affinity Amino Acids Antisense RNA Arrhythmia Axon Back Binding Binding Sites Bioinformatics Ca(2+)-Transporting ATPase Cardiac Cell membrane Cells Codon Nucleotides DRADA2b protein Data Dependence Depressed mood Disease Double-Stranded RNA Binding Domain Dystonia 12 Endoplasmic Reticulum Enzymes Equilibrium Familial Hemiplegic Migraine Fiber Financial compensation Future GTP-Binding Proteins Ganglia Genes Genetic Glutamate Receptor Goals Hereditary Disease Human Hydrophobicity Ions Lead Learning Letters Link Lobe Membrane Part Membrane Potentials Messenger RNA Methods Modeling Molecular Molecular Conformation Mutation Myxoid cyst N Domain Nature Nervous system structure Neuraxis Nomenclature Nucleotides Oligonucleotides Optic Lobe Pathology Peripheral Permeability Phosphorylation Physiological Phytic Acid Play Population Positioning Attribute Potassium Channel Process Protein Isoforms Proteins Public Health Publishing Pump RNA Editing Regulation Research Role Shotguns Signal Transduction Site Squid Steroids Structure Structure of stellate ganglion Surface Synapses System Tertiary Protein Structure Testing Time Trefoil Motif Vertebrates Work base digoxin receptor dsRNA adenosine deaminase extracellular gain of function mutant neuronal cell body null mutation public health relevance receptor binding relating to nervous system serotonin receptor solute therapeutic development tool voltage

项目摘要

DESCRIPTION (provided by applicant): This project focuses on how the Na/K pump is regulated by RNA editing. A central premise to our approach is that naturally occurring codon changes, caused by RNA editing, can lead us to functionally important regions of the Na/K pump. They might also be used as tools to compensate for rapid-onset dystonia parkinsonism, genetic disease associated with the human Na/Ka3 subunit. The squid nervous system will be used as a model because RNA editing is extensive in cephalopods and because the editing sites that we have identified cause a gain of function, a rare phenomenon for a mutation. Preliminary data show that Na/K pump mRNAs can be edited at three codons, two in the phosphorylation domain (P), and the other at the top of the 7th transmembrane span (M7). These changes affect critical components of the pumping cycle. For example, the edits in the P domain increase the apparent affinity for ATP and the edit in M7 regulates how Na is released to the outside. Using an electrophysiological approach, the proposal's first two aims will characterize the mechanism by which these edits exert their function. The goal of the last aim is to see whether squid RNA edits can compensate for depressed turnover rates in human Na/Ka3 caused by mutations associated with rapid-onset dystonia parkinsonism. In addition, not only will we study if they can compensate, we will also try to develop a method to introduce these edits into human pumps at the level of mRNA. Preliminary data show that the human editing enzyme ADAR2 is capable of editing squid mRNAs because it recognizes the appropriate secondary structure. We hypothesize that we can trick human ADAR2 into editing human pumps by mimicking the squid secondary structure with an antisense RNA oligo. From the standpoint of public health, this work is significant on several fronts. The Na/K pump creates the ion gradient that is required for excitability and the majority of solute transport across cell membranes. With the first crystal structure recently published, this is an opportune time to learn more about how the Na/K pump operates. Clinically, the Na/K pump is important because it is the receptor of digoxin, a widely prescribed cardiac steroid used to control many cardiac arrhythmias. Further, two neural disorders have been directly correlated with mutations to the Na/K pump: familial hemiplegic migraine, which is linked to the Na/Ka2 subunit, and rapid-onset dystonia parkinsonism, which is linked to the Na/Ka3 subunit. Results from this proposal will be directly relevant to the development of therapeutics for rapid-onset dystonia parkinsonism. The general approach may also prove relevant for a wide variety of genetic disorders. PUBLIC HEALTH RELEVANCE: The Na/K pump plays a vital role in establishing ion gradients across cells. Preliminary data shows that its ability to pump can be regulated by RNA editing. This proposal focuses on understanding how RNA editing regulates the Na/K pump and how it might be used to treat genetic disorders that affect the Na/K pump.

描述（由申请人提供）：该项目的重点是如何通过RNA编辑调节Na/K泵。我们方法的一个中心前提是，由RNA编辑引起的自然发生的密码子变化可以使我们进入Na/k泵的功能重要区域。它们也可能被用作补偿帕金森氏症快速发作，与人Na/Ka3亚基相关的遗传疾病。鱿鱼神经系统将被用作模型，因为RNA编辑在头足动物中是广泛的，并且我们已经确定的编辑位点会导致功能增长，这是突变的罕见现象。初步数据表明，Na/k泵mRNA可以在三个密码子，磷酸化结构域（P）中进行编辑，另一个在第7跨膜跨度（M7）的顶部进行编辑。这些变化影响泵送周期的关键组成部分。例如，P域中的编辑增加了对ATP的明显亲和力，而M7中的编辑调节了NA如何释放到外部。使用电生理方法，该提案的前两个目标将表征这些编辑功能的机制。最后一个目的的目的是查看鱿鱼RNA编辑是否可以弥补由与快速发作肌张力障碍帕金森氏症相关的突变引起的人Na/ka3的降低营业率。此外，我们不仅可以研究它们是否可以补偿，还将尝试开发一种将这些编辑引入mRNA水平的人泵的方法。初步数据表明，人类编辑酶ADAR2能够编辑鱿鱼mRNA，因为它识别出适当的二级结构。我们假设我们可以通过用反义RNA Oligo模仿鱿鱼二级结构来欺骗人类ADAR2来编辑人泵。从公共卫生的角度来看，这项工作在几个方面都很重要。 Na/k泵产生了兴奋性和大多数溶质转运所需的离子梯度。随着最近发布的第一个晶体结构，这是一个适当的时机，以了解有关Na/K泵的运作方式的更多信息。在临床上，Na/k泵很重要，因为它是地高辛的受体，地高辛是一种广泛的心脏类固醇，用于控制许多心律不齐。此外，两种神经疾病已与Na/k泵的突变直接相关：与Na/ka2亚基有关的家族性偏瘫偏头痛和与Na/ka3亚基有关的快速发作的肌张力蛋白症。该提案的结果将与帕金森氏症快速发作肌张力障碍的治疗剂的发展直接相关。一般方法也可能证明与多种遗传疾病有关。公共卫生相关性：Na/k泵在建立细胞的离子梯度中起着至关重要的作用。初步数据表明，它的泵送能力可以通过RNA编辑来调节。该建议着重于了解RNA编辑如何调节Na/K泵，以及如何使用它来治疗影响Na/k泵的遗传疾病。