Structural studies of RNA processing and ubiquitin-like protein modification

RNA加工和类泛素蛋白修饰的结构研究

• 批准号: 10395543
• 负责人: CHRISTOPHER D. LIMA
• 金额: $ 45.58万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-10 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10395543
• 关键词: Address; Biochemical Genetics; Biology; Cell Cycle Progression; Cell Cycle Proteins; Cell Cycle Regulation; Cell physiology; Chemicals; Chromosome Segregation; Complex; Cytokinesis; Defect; Disease; Enzymes; Equilibrium; Eukaryota; Exoribonucleases; Genes; Genetic Transcription; Genetic study; Health; Homeostasis; Human; In Vitro; Inflammation; Life; Ligase; M cell; Malignant Neoplasms; Metabolism; Mission; Modification; Molecular; Monitor; Motor; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Nuclear; Pathway interactions; Peptide Hydrolases; Play; Post-Translational Protein Processing; Process; Protein Complex Subunit; Proteins; RNA; RNA Decay; RNA Processing; Regulation; Reporting; Role; Saccharomycetales; Signal Transduction; Structure; Transcriptional Regulation; Ubiquitin; Ubiquitin Like Proteins; United States National Institutes of Health; cofactor; enzyme mechanism; exosome; human disease; in vivo; nucleic acid metabolism; nucleocytoplasmic transport; protein degradation; receptor; reconstitution

RNA decay. The balance between RNA transcription and degradation contributes to regulation of RNA lifetime, quality and abundance. Two principle RNA decay pathways exist in eukaryotes, one degrades RNA 5’ to 3’ while the other degrades RNA 3’ to 5’. The 3’ to 5’ decay pathway requires activities of the RNA exosome, a multi-subunit protein complex that contains a nine-subunit non-catalytic core and two additional subunits that catalyze processive and distributive 3’ to 5’ RNA exoribonuclease activities. Ten of the eleven genes are essential for life in budding yeast, suggesting the importance of the RNA exosome and its activities in cellular function. In addition, reports over the last several years suggest that humans harboring mutations in select components of the 3’ to 5’ decay pathway suffer from diseases ranging from motor neuronopathies to cancer. Fundamental aspects of eukaryotic exosome structure and function have been illuminated; however, many questions remain with respect to how upstream factors target substrates for degradation. As RNA decay pathways play a fundamental role in eukaryotic nucleic acid metabolism and disease, our studies are directly relevant to human health and the NIH mission as misregulation of RNA decay is associated with cancer, inflammation and neurodegeneration. This renewal will address central issues of RNA exosome biology by reconstituting or purifying RNA exosomes and upstream factors for characterization through biochemical, genetic and structural studies to establish functions for 3’ to 5’ decay in vitro and in vivo. Ubiquitin-like proteins. Signal transduction can rely on reversible chemical modifications to relay information. Protein substrates can be covalently modified by ubiquitin and ubiquitin-like proteins such as SUMO (small ubiquitin-like modifier) to regulate processes such as nuclear transport, cytokinesis, chromosome segregation, G2-M cell cycle progression and transcription. Post-translational modification by ubiquitin (Ub) and ubiquitin- like (Ubl) proteins requires the sequential action of E1 activating enzymes, E2 conjugating enzymes and E3 protein ligases while Ub/Ubl processing and deconjugation is catalyzed by Ub/Ubl-specific proteases. Ubiquitin and SUMO conjugation play integral roles in eukaryotic nuclear metabolism and cell cycle control and our studies are of direct relevance to human health, cancer, and the mission of the NIH. This renewal seeks to address the functional significance for components of the ubiquitin and SUMO conjugation pathways through structural, biochemical and genetic studies that will establish a basis for Ub/Ubl activation, conjugation by E2 and E3 enzymes, and signaling through characterization receptors that recognize Ub/Ubl-conjugated substrates. The enzymes, mechanisms and cofactors utilized for ubiquitin and SUMO protein conjugation pathways are conserved so our studies are broadly relevant to other Ub/Ubl-related pathways.

核糖核酸会腐烂。RNA转录和降解之间的平衡有助于调节RNA 终生、质量、富足。真核生物中存在两条主要的RNA衰变途径，一条是降解RNA5‘ 另一种将RNA降解为3‘到5’。3‘到5’衰变途径需要RNA外切体的活动， 一种多亚单位蛋白质复合体，包含一个九亚单位非催化核心和另外两个亚基， 催化进行性和分布性3‘到5’RNA外切核糖核酸酶活性。这11个基因中有10个是 对萌芽酵母的生命是必不可少的，这表明了RNA外切体及其在细胞中的活动的重要性 功能。此外，过去几年的报告表明，人类在SELECT基因中存在突变 从运动神经疾病到癌症，3‘到5’衰变途径的组成部分都会遭受疾病的折磨。 已经阐明了真核外切体结构和功能的基本方面；然而，许多 关于上游因素如何针对底物进行降解的问题仍然存在。随着RNA的衰变 通路在真核细胞核酸代谢和疾病中起着基础性作用，我们的研究直接 与人类健康和美国国立卫生研究院的任务有关，因为RNA衰变的错误调节与癌症有关， 炎症和神经退行性变。这一更新将通过以下方式解决RNA外显体生物学的中心问题 重组或纯化RNA外切体和上游因子，通过生化鉴定， 在体外和体内进行遗传和结构研究，以确定3‘到5’腐烂的功能。 泛素样蛋白。信号转导可以依靠可逆的化学修饰来传递信息。 蛋白质底物可以被泛素和类似泛素的蛋白质共价修饰，如SUMO(Small 泛素样修饰物)来调节诸如核运输、胞质分裂、染色体分离、 G2-M细胞周期进程和转录。泛素(Ub)和泛素的翻译后修饰 类(Ub1)蛋白需要E1激活酶、E2结合酶和E3的顺序作用 蛋白质连接酶在Ub/Ub1的加工和去结合过程中是由Ub/Ub1特异性的酶催化的。泛素 和相扑结合在真核细胞的核代谢和细胞周期调控中发挥着不可或缺的作用，我们的 研究与人类健康、癌症和美国国立卫生研究院的使命直接相关。此次续签旨在 通过以下途径阐述泛素和相扑结合途径组件的功能意义 结构、生化和遗传学研究，将为Ub/Ub1激活、与E2接合奠定基础 和E3酶，以及通过识别Ub/Ub1结合的特征化受体的信号 底物。泛素与相扑蛋白偶联的酶、作用机制及辅因子 通路是保守的，所以我们的研究与其他Ub/Ubl相关的通路广泛相关。