Eukaryotic RNA NAD capping and deNADding

真核 RNA NAD 加帽和 deNADding

• 批准号: 10443996
• 负责人: MEGERDITCH KILEDJIAN
• 金额: $ 36.51万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-27 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10443996
• 关键词: Address; Aging; Amino Acids; Area; Assimilations; Bacteria; Biological; Biological Models; Biological Process; Biology; COVID-19; Cell Nucleus; Cell physiology; Cells; Cellular Stress; Complex; DNA; Data; Disease; Elements; Enzymes; Eukaryota; Eukaryotic Cell; Excision; Gene Expression; Growth; Homeostasis; Human; In Vitro; Link; Mammalian Cell; Messenger RNA; Metabolic stress; Metabolism; Mitochondria; Mitochondrial Proteins; Mitochondrial RNA; Molecular; Nicotinamide adenine dinucleotide; Nuclear; Nuclear Decay; Nuclear RNA; Nutrient; Organism; Pathway interactions; Physiological; Play; Post-Transcriptional Regulation; Process; Publishing; RNA; RNA Caps; RNA Decay; RNA Polymerase II; RNA metabolism; RNA vaccine; Regulation; Research; Respiration; Role; Saccharomyces cerevisiae; Saccharomycetales; Starvation; Stress; Testing; Therapeutic; Transcript; Virus; Work; Yeasts; decapping enzyme; defined contribution; epitranscriptomics; genetic information; insight; mitochondrial dysfunction; novel; novel strategies; nuclease; poly A specific exoribonuclease; response; senescence; sugar

RNA 5′ end capping provides a layer of “epitranscriptomic” regulation, influencing numerous aspects of RNA fate, including stability, processing, localization and translatability. Furthermore, enzymes that remove RNA 5′ end caps play critical roles in modulating these processes. Recently, a previously unknown form of RNA 5'-end capping has been identified in bacterial, yeast, and human cells. In this new form of RNA capping, the metabolite nicotinamide adenine dinucleotide (NAD) is added at the RNA 5′ end. In contrast to 7- methylguanylate (m7G) caps, which are added to mRNAs by a complex that associates with eukaryotic RNA polymerase II (RNAP II), NAD caps are primarily added by RNAP itself in bacteria and eukaryotic nuclear and mitochondrial transcripts. Thus, unlike m7G capping, which is observed in eukaryotes and certain eukaryotic viruses, NAD capping is likely to occur in most, if not all, organisms. Our recently published work along with our unpublished preliminary data, indicates that NAD capping targets mammalian RNAs for rapid decay. In addition, we have shown eukaryotic cells possess several enzymes capable of removing NAD caps and, furthermore, that the cellular functions of these “deNADding” enzymes are most evident during metabolic stress. An overall theme emerging from our data is that addition and removal of NAD caps play critical roles in mitochondrial function where NAD-capped mitochondrial-encoded transcripts and nuclear transcripts encoding mitochondrial proteins are modulated by NAD caps. To decipher the interplay between cellular assimilation of NAD and RNA metabolism we will define the functional role(s) of NAD caps and deNADding enzymes in both budding yeast and mammalian cells. The first aim will investigate the hypothesis that NAD capping of mitochondrial RNA plays a key role in maintaining NAD homeostasis with the NAD cap serving as a reservoir to sequester and release free NAD for proper mitochondrial energetics. The second aim will investigate the impact of NAD capping on nuclear encoded RNA and, in particular, explores the hypothesis that NAD capping in budding yeast provides a mechanism for the targeted decay of RNAs in response to nutrient stress. The third aim will determine how the NAD capping and deNADding of mammalian nuclear mRNAs encoding mitochondrial proteins contributes to mitochondrial function upon cellular stress and whether perturbation of the deNADding of these mRNAs contributes to mitochondrial dysfunction associated with aging. The proposed studies will provide new insight in an emerging area of RNA biology, post- transcriptional regulation in cellular metabolism and, furthermore, may provide a mechanistic framework for developing new approaches to control gene expression in normal and disease states.

RNA 5′端加帽提供了一层“表转录组”调控，影响RNA的许多方面。 命运，包括稳定性，加工，本地化和可译性。此外，去除RNA的酶 5′端帽在调节这些过程中起着关键作用。最近，一种以前未知的RNA 已在细菌、酵母和人类细胞中鉴定出5 '-末端加帽。在这种新形式的RNA加帽中， 代谢产物烟酰胺腺嘌呤二核苷酸（NAD）被添加在RNA 5′端。与7相比， 甲基鸟苷酸（m7 G）帽，通过与真核RNA结合的复合物添加到mRNA上 RNA聚合酶II（RNAP II），NAD帽主要由RNAP本身添加到细菌和真核细胞核中， 线粒体转录本。因此，与在真核生物和某些真核生物中观察到的m7 G加帽不同， 与病毒一样，NAD加帽可能发生在大多数（如果不是全部）生物体中。我们最近发表的工作沿着 我们未发表的初步数据表明，NAD加帽靶向哺乳动物RNA快速衰变。在 此外，我们已经证明真核细胞具有几种能够去除NAD帽的酶， 此外，这些“去NADding”酶的细胞功能在代谢过程中最为明显。 应力从我们的数据中出现的一个总体主题是，添加和去除NAD上限发挥关键作用 在线粒体功能中，NAD加帽的线粒体编码的转录本和核转录本 编码线粒体蛋白的基因由NAD帽调控。为了破译细胞之间的相互作用， 我们将定义NAD帽和去NAD化的功能作用， 芽殖酵母和哺乳动物细胞中的酶。第一个目标将调查的假设，NAD 线粒体RNA的加帽在维持NAD稳态中起关键作用，NAD帽充当 一个水库，以隔离和释放游离NAD适当的线粒体能量。第二个目标将 研究NAD加帽对核编码RNA的影响，特别是探讨了假设 芽殖酵母中的NAD加帽为RNA的靶向衰变提供了一种机制， 营养胁迫第三个目标是确定哺乳动物细胞核的NAD加帽和去NAD化是如何发生的。 编码线粒体蛋白的mRNA在细胞应激时有助于线粒体功能， 这些mRNAs的去NADing的扰动是否有助于线粒体功能障碍相关的 随着年龄的增长。拟议的研究将为RNA生物学的新兴领域提供新的见解， 转录调控的细胞代谢，而且，还可以提供一个机制框架， 开发新的方法来控制正常和疾病状态下的基因表达。