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 Our recently published work along with our unpublished preliminary data, indicates that NAD capping targets mammalian RNAs for rapid decay.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' 末端加帽提供了一层“表转录组”调控，影响 RNA 的多个方面 命运，包括稳定性、处理、本地化和可翻译性。此外，去除 RNA 的酶 5' 端盖在调节这些过程中发挥着关键作用。最近，一种以前未知的RNA形式 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， 代谢物烟酰胺腺嘌呤二核苷酸 (NAD) 添加在 RNA 5' 端。与 7- 相比 甲基鸟苷酸 (m7G) 帽，通过与真核 RNA 结合的复合物添加到 mRNA 上 聚合酶 II (RNAP II)，NAD 帽主要由细菌和真核细胞核中的 RNAP 本身添加 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 m7G 加帽不同 病毒中，NAD 加帽可能发生在大多数（如果不是全部）生物体中。我们最近发表的作品以及 我们未发表的初步数据表明，NAD 加帽针对哺乳动物 RNA 进行快速衰减。在 此外，我们已经证明真核细胞拥有多种能够去除 NAD 帽的酶，并且， 此外，这些“deNADding”酶的细胞功能在代谢过程中最为明显。 压力。我们的数据中出现的一个总体主题是 NAD 上限的添加和取消发挥着关键作用 在线粒体功能中，NAD 加帽的线粒体编码转录本和核转录本 编码线粒体蛋白的蛋白由 NAD 帽调节。破译细胞之间的相互作用 NAD 和 RNA 代谢的同化我们将定义 NAD 帽和 deNADding 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 NAD 的假设 线粒体 RNA 的加帽在维持 NAD 稳态中发挥着关键作用，其中 NAD 帽充当 一个储存库，用于隔离和释放游离 NAD，以实现适当的线粒体能量学。第二个目标将 研究 NAD 加帽对核编码 RNA 的影响，特别是探索假设 芽殖酵母中的 NAD 封盖提供了一种机制，用于响应 RNA 的靶向衰减 营养压力。第三个目标将确定哺乳动物核的 NAD 加帽和脱 NAD 的方式 编码线粒体蛋白的 mRNA 有助于细胞应激和线粒体功能 这些 mRNA 的 deNADding 的扰动是否会导致相关的线粒体功能障碍 随着衰老。拟议的研究将为 RNA 生物学的新兴领域提供新的见解。 细胞代谢中的转录调控，此外，可能提供一个机制框架 开发新方法来控制正常和疾病状态下的基因表达。