Regulation of Mammalian mRNA Decay

哺乳动物 mRNA 衰变的调控

• 批准号: 10350594
• 负责人: MEGERDITCH KILEDJIAN
• 金额: $ 37.98万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10350594
• 关键词: Address; Adenine; Affect; Affinity; Binding; Cell Extracts; Cell physiology; Cells; Cellular Stress; Complex; DNA; Diphosphates; Disease; Elements; Enzymes; Eukaryota; Flavin-Adenine Dinucleotide; Flavins; Foundations; Gene Expression; Genetic Transcription; Genetic Translation; Guanosine; Homeostasis; Human; Hydrolase; In Vitro; Kinetics; Link; Malignant Neoplasms; Mammalian Cell; Mediating; Messenger RNA; Metabolism; Minor; Mitochondria; Molecular; NADH; Nature; Nicotinamide adenine dinucleotide; Nucleotides; Oxidation-Reduction; Pharmacology; Physiological; Post-Transcriptional Regulation; Prevalence; Proteins; Proto-Oncogenes; RNA; RNA Cap-Binding Proteins; RNA Caps; RNA Decay; RNA Stability; RNA metabolism; Regulation; Role; Stress; Translations; Work; base; clinical phenotype; cofactor; exosome; genetic information; insight; mRNA Decay; mRNA Stability; mRNA capping; novel; novel strategies; nuclease; spleen exonuclease

Project Summary The control of mRNA stability is a critical determinant in the post-transcriptional regulation of eukaryotic gene expression. Even minor alterations in mRNA stability can have profound consequences and may manifest as clinical phenotypes as illustrated by the ability of aberrantly expressed proto-oncogenes that can give rise to malignancies. Eukaryotic mRNAs are generally thought to possess an N7 methyl guanosine (m7G) cap at their 5¢ end to promote their stability and translation. However, our recent demonstration that mammalian mRNAs can also carry a 5´-end nicotinamide adenine dinucleotide (NAD) cap that in contrast to the m7G cap promotes mRNA decay, provides a new paradigm for mRNA 5´ end processing and the contribution of nucleotide metabolites in mRNA turnover. We now demonstrate that the redox state of NAD can also modulate 3´ RNA decay with free NAD functioning as a cofactor to enhance RNA decay and potentially providing a link to cellular energetics. Moreover, flavin adenine diphosphate (FAD) can also serve as a 5´ cap on mammalian RNAs with Nudt16 and DXO hydrolases functioning as proteins that can remove the FAD cap (deFADding) in vitro. We will build on these novel findings throughout this proposal within three specific aims. The first will address the functional role of free NAD on the control of 3´ end RNA decay in vitro and delineate the molecular mechanism involved in its stimulation of decay. The second will deduce changes in mRNA decay as a consequence of altered NAD levels in cells and assess the regulatory role imparted by stress conditions in modulating RNA decay through the control of NAD levels. In the last aim, we establish FAD cap as an alternative RNA cap, identify FAD-capped RNAs and decipher the role of FAD caps and the deFADding enzymes in cells. Collectively, the proposed studies will provide insight into a heretofore unknown fundamental post-transcriptional regulatory mechanism and will provide the framework for potential novel avenues to control gene expression in normal and disease states.

项目概要 mRNA稳定性的控制是真核生物转录后调控的关键决定因素 即使 mRNA 稳定性发生微小变化也可能产生深远的后果。 表现为临床表型，如异常表达原癌基因的能力所示 通常认为真核生物的 mRNA 具有 N7 甲基。 鸟苷 (m7G) 上限为 5 美分，以促进其稳定性和转化。 证明哺乳动物 mRNA 也可以携带 5´ 端烟酰胺腺嘌呤二核苷酸 (NAD) 帽与 m7G 帽相反，促进 mRNA 衰减，为 mRNA 提供了新的范例 5´ 末端加工和核苷酸代谢物对 mRNA 周转的贡献。 证明 NAD 的氧化还原态也可以通过游离 NAD 功能调节 3´ RNA 衰变 作为增强 RNA 衰变的辅助因子，并有可能提供与细胞能量学的联系。 黄素腺嘌呤二磷酸 (FAD) 还可以作为哺乳动物 RNA 的 5´ 帽，具有 Nudt16 和 DXO 水解酶作为蛋白质发挥作用，可以在体外去除 FAD 帽 (deFADding)。 该提案以这些新颖的发现为基础，实现了三个具体目标。 游离 NAD 在体外控制 3´ 端 RNA 衰变中的功能作用并描述分子 第二个机制将 mRNA 衰变的变化推导出来。 细胞中 NAD 水平改变的结果并评估应激条件赋予的调节作用 通过控制 NAD 水平来调节 RNA 衰减 在最后一个目标中，我们将 FAD 上限建立为 替代 RNA 帽，识别 FAD 帽 RNA 并破译 FAD 帽的作用和 总的来说，拟议的研究将提供对迄今为止细胞中 deFADding 酶的深入了解。 未知的基本转录后调控机制，并将提供框架 控制正常和疾病状态下基因表达的潜在新途径。