A New Non-Canonical Role for an Alternatively Translated Ion Channel Protein

替代翻译的离子通道蛋白的新非典型作用

基本信息

批准号：
10092407
负责人：
Robin M Shaw
金额：
$ 38.13万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-01 至 2022-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10092407
关键词：
Accounting Actins Adenoviruses Adult Arrhythmia Biological Biological Process Biology C-terminal Cardiac Cardiac Electrophysiologic Techniques Cardiac Myocytes Cardiovascular Diseases Cardiovascular system Cause of Death Cell Communication Cell Cycle Progression Cell Maintenance Cell Survival Cell membrane Cells Cessation of life Charge Code Connexin 43 Connexins Consumption Critical Pathways Data Development Disease Distal Epithelial Epithelium Exons Failure Gene Transfer Genes Genetic Transcription Goals Heart Heart failure Hydrogen Peroxide Infarction Initiator Codon Injury Intercalated disc Ion Channel Ion Channel Protein Ischemia Laboratories Length Mediating Mesenchymal Messenger RNA Metabolism Methionine Mitochondria Modeling Morbidity - disease rate Movement Mus Myocardial Myocardial Ischemia Myocardium N-terminal Organelles Outcome Oxidative Stress Parents Pathogenesis Pathologic Peptides Phenotype Process Protein Isoforms Protein Truncation Proteins RNA Splicing Regulation Reperfusion Therapy Research Ribosomes Role Science Signal Transduction Stress Tail Testing Therapeutic Transcript Translating Translations Tropism United States United States National Institutes of Health Ventricular Work base cardioprotection gap junction channel gene therapy heart function improved in vivo ischemic injury migration mortality mouse model myocardial injury new therapeutic target novel therapeutic intervention novel therapeutics peptide drug preservation sudden cardiac death targeted delivery therapeutic development tool trafficking wound healing

项目摘要

Ion channels have a plethora of functions than, frequently, can not be understood by their ability to insert in the plasma membrane and conduct ionic current. The Connexin43 (Cx43) gap junction channel, whose parent gene is GJA1, has been implicated in having a role in cell cycle progression, metastatic transformation, wound healing, development, migration, epithelial-mesenchymal transition, and metabolism. GJA1 has a single coding exon, and therefore it can not be subject to splicing and alternative transcription. However we have identified, and it has been confirmed by several laboratories, that GJA1 mRNA is subject to alternative translation in which initiation of ribosomal translation occurs not at the first AUG (Methionine) start codon, but at downstream Methionines. The result is that six additional progressive N-terminal truncation proteins (all containing the distal C- terminus) can be endogenously generated from the same mRNA molecule, which we identify by protein size (GJA1-43k for the full length protein, then GJA1-32k, GJA1-29k, GJA1-26k, GJA1-20k, GJA1-11k, and GJA1-7k). For the last three years, my group has explored the role of these smaller isoforms. This proposal is based on the application of a surprising, and frankly startling, finding regarding GJA1-20k which is usually the most highly translated of the smaller isoforms. We found that GJA1-20k has a strong tropism for mitochondria, so strong that it could function as a mitochondrial marker. Additional preliminary data indicate that GJA1-20k is protective against the stress of myocardial ischemia. Our central hypothesis is that following oxidative stress and ischemic injury, alternatively translated endogenous GJA1-20k is increased and targets to mitochondria as a myocardial survival signal. Furthermore, we will test whether exogenous GJA1-20k can reduce myocardial injury due to ischemic insult. Three specific aims are proposed. Aim #1- What is the expression, localization, and function of GJA1-20k during myocardial injury? Aim #2- Does exogenous GJA1-20k improves cardiomyocyte survival following oxidative stress? Aim #3- Does gene transfer of GJA1-20k reduce infarct size in a mouse model of myocardial ischemia? When the work in the three aims is complete, we expect to have identified critical pathways of GJA1-20k regulation during stress and have introduced a new therapeutic peptide for ischemic injury. Furthermore, we will develop the paradigm by which alternative translation is an important aspect of cardiac electrophysiology and should be applied to multiple channels as a means for understanding the mechanism of their non-canonical function.

离子通道具有大量功能，而不是经常无法通过其能力来理解插入质膜并进行离子电流。 Connexin43（CX43）间隙连接其母体基因为GJA1的通道已与在细胞周期进程中起作用，转移性转化，伤口愈合，发育，迁移，上皮间质转变，和新陈代谢。 GJA1具有单个编码外显子，因此不能受到剪接和替代转录。但是我们已经确定了，并且已经得到了几个实验室，GJA1 mRNA受到核糖体开始的替代翻译翻译不是在第一个8月（蛋氨酸）起始密码子，而是在下游蛋白质发生。这结果是六个额外的进行性N末端截断蛋白（全部包含远端C- 末端可以是由同一mRNA分子内源产生的，我们通过蛋白质鉴定尺寸（全长蛋白质的GJA1-43K，然后是GJA1-32K，GJA1-29K，GJA1-26K，GJA1-20K，GJA1-11K，和gja1-7k）。在过去的三年中，我的小组探讨了这些较小的同工型的作用。这提案基于关于GJA1-20K的惊人和坦率地发现令人惊讶且令人震惊的信息通常是较小的同工型的最高翻译。我们发现GJA1-20K有一个线粒体的强度强度很强，以至于它可以充当线粒体标记。额外的初步数据表明，GJA1-20K可以抵抗心肌缺血的压力。我们的中心假设是氧化应激和缺血性损伤，替代翻译内源性GJA1-20K增加了，将线粒体作为心肌存活信号的目标增加。此外，我们将测试外源GJA1-20K是否可以减少因缺血而减少心肌损伤侮辱。提出了三个具体目标。目标＃1-心肌损伤期间GJA1-20K的表达，定位和功能是什么？ AIM＃2-外源GJA1-20K是否可以改善氧化应激后心肌细胞的存活？ AIM＃3- GJA1-20K的基因转移会减少心肌缺血的小鼠模型中的梗死大小吗？当三个目标完成时，我们希望已经确定了关键途径 GJA1-20K在压力期间调节，并引入了一种新的治疗性肽，以用于缺血性损伤。此外，我们将开发范式，替代翻译是心脏电生理学，应应用于多个通道，以了解其非规范功能的机制。