In-Vivo Regulation of ADAR2 Activity by Autoediting

通过自动编辑体内调节 ADAR2 活性

• 批准号: 6651512
• 负责人: CHRISTOPHER L SANSAM
• 金额: $ 1.96万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6651512
• 关键词: adenosine deaminase; gene targeting; genetic regulation; glutamate receptor; laboratory mouse; messenger RNA; posttranscriptional RNA processing; predoctoral investigator

The diversity of synaptic signaling is partly generated by the presence of multiple receptor isoforms that respond to a neurotransmitter by activating separate downstream signals. In the mammalian central nervous system, the repertoire of receptors is expanded beyond the genomically encoded set by a process known as A-to-I RNA editing. It has been discovered that adenosines are converted to inosines within duplexes formed by precurser-mRNAs that code for several ionotropic glutamate receptor subunits and the 2C-subtype of the serotonin receptor (5-HT2cR), and the resulting altered mRNAs code for functionally distinct receptors. Two double-stranded RNA binding adenosine deaminases called ADAR1 and ADAR2 are responsible for precise A-to-I editing of those neuronal transcripts. Recent studies suggest that the appropriate regulation of the expression of ADAR2 is critical for maintaining editing site selectivity, and misregulation of ADAR2 expression in mice leads to extreme obesity (Emeson, unpublished results). A newly discovered A-to-I editing event in the pre-mRNA encoding ADAR2 itself suggests that a quite unique form of regulation of ADAR2 activity occurs, where ADAR2 may negatively regulate its own expression by editing its own transcript. The ultimate aim of this proposal is to test the significance of ADAR2 autoediting. This will be accomplished by studying ADAR2 mRNA and protein expression in mice genetically engineered to lack ADAR2 autoediting, and the resulting changes of editing patterns in known substrates of ADAR2 will be examined.

突触信号的多样性部分是由多种受体亚型的存在产生的，这些受体亚型通过激活单独的下游信号来响应神经递质。在哺乳动物的中枢神经系统中，通过称为 A-to-I RNA 编辑的过程，受体库被扩展到基因组编码之外。已经发现，腺苷在由前体 mRNA 形成的双链体中转化为肌苷，前体 mRNA 编码几种离子型谷氨酸受体亚基和 5-羟色胺受体 (5-HT2cR) 的 2C 亚型，并且由此产生的改变的 mRNA 编码功能不同的受体。两种双链 RNA 结合腺苷脱氨酶 ADAR1 和 ADAR2 负责对这些神经元转录本进行精确的 A 到 I 编辑。最近的研究表明，ADAR2 表达的适当调节对于维持编辑位点选择性至关重要，而小鼠中 ADAR2 表达的错误调节会导致极度肥胖（Emeson，未发表的结果）。编码 ADAR2 本身的前 mRNA 中新发现的 A-to-I 编辑事件表明 ADAR2 活性发生了一种非常独特的调节形式，其中 ADAR2 可能通过编辑其自身转录本来负向调节其自身表达。该提案的最终目的是测试 ADAR2 自动编辑的重要性。这将通过研究基因工程缺乏 ADAR2 自动编辑的小鼠中 ADAR2 mRNA 和蛋白质表达来实现，并且将检查 ADAR2 已知底物中编辑模式的变化。