Molecular mechanisms of eukaryotic translational control

真核翻译控制的分子机制

• 批准号: 10445573
• 负责人: Sarah Elizabeth Walker
• 金额: $ 30.03万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-27 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10445573
• 关键词: 5' Untranslated Regions; Address; Affect; Affinity; Behavior; Binding; Biological Assay; C-terminal; Cell physiology; Cells; Complex; Cryoelectron Microscopy; Cytoplasmic Granules; Data; Dependence; Disease; Disseminated Malignant Neoplasm; Early Diagnosis; Early treatment; Eukaryotic Initiation Factors; Event; Future; Gel; Genetic; Genetic Translation; Growth; In Vitro; Knowledge; Light; Link; Malignant Neoplasms; Mammals; Mechanics; Mediating; Messenger RNA; Mitotic; Modeling; Modification; Molecular; Mus; Mutation; Neoplasm Metastasis; Outcome; Pathogenesis; Pathway interactions; Patient-Focused Outcomes; Patients; Peptide Initiation Factors; Phenotype; Phosphorylation; Play; Post-Translational Protein Processing; Protein Biosynthesis; Proteins; Proteome; RNA; RNA Binding; RNA Helicase; RNA Recognition Motif; RNA Sequences; RNA vaccine; Reporter; Repression; Ribosomal Proteins; Ribosomes; Role; Scanning; Signal Transduction; Site; Specificity; Structure; Testing; Transcript; Translating; Translation Initiation; Translations; Work; Yeasts; cancer therapy; cell behavior; cell growth; cofactor; eIF-4B; experience; genome-wide; human disease; improved; in vitro Assay; in vitro activity; mRNA capping; malignant breast neoplasm; mutation screening; patient prognosis; preference; programs; recruit; response; ribosome profiling; therapeutic target; tool; transcriptome; tumor progression; tumorigenic

SUMMARY: The level of each protein synthesized in a cell results from both the amount of mRNA available, and the number of ribosomes that initiate translation of that mRNA. Eukaryotic translation initiation factors (eIFs) can reprogram which mRNAs are available and translated to produce different levels of the encoded proteins in response to discrete cellular signals. In fungal species, translational control plays important roles in host evasion and other pathogenesis mechanisms, and in mammalian species, altered levels and modifications of eIFs influence cancer progression and other disease states. A number of protein factors stimulate translation, including the eIF4 factors (4A, B, E, G, and H) that engage the 5’ cap of mRNA and the small subunit of the ribosome, to promote events prior to start site recognition. Ample data support roles of the RNA helicase 4A and cofactors 4B and 4G in unwinding 5’ UTRs to promote translation of structured mRNAs. However, the mRNAs that depend on 4B activity for translation are distinct from those that rely heavily on 4G, even though both factors promote 4A activity. Moreover, in striking contrast to protumorigenic 4A and 4G, increased levels of 4B improved survival of patients with aggressive cancers, and preliminary data directly implicated 4B in opposing metastasis of murine breast cancers. Understanding how 4B mediates translation of specific transcripts could be important for understanding and predicting metastatic phenotypes. Finally, posttranslational modifications of the eIF4 factors are known to modulate translation in mammals, and deregulation is common in disease states. However, it is unclear how modifications of the eIF4 factors regulate translation in fungal species and how this affects expression of specific mRNA pools. This proposal takes on these challenges, investing years of experience characterizing the mechanics of yeast translation initiation and a powerful arsenal of in vitro, genetic, and genome- wide tools. In order to better understand how mRNAs are selected by ribosomes for translation, the objective of this work is to understand how 4B achieves translation versus repression of specific mRNA pools in yeast. Three aims will be pursued: Aim 1. Determine how 4F and 4B interactions affect translation of 4B hyper and hypo-dependent mRNAs. Aim 2. Elucidate yeast 4B- RNA binding preferences. Aim 3. Understand how posttranslational modifications (PTMs) of 4F and 4B impact 4B-specific mRNA control. This proposal will use eIF4B as a model to determine how core translation initiation factors modulate translation versus repression of specific mRNA pools and will shed light on how robust activity of 4B opposes the metastatic phenotype.

概括： 细胞中合成的每种蛋白质的水平取决于可用 mRNA 的量，以及 启动该 mRNA 翻译的核糖体数量。 (eIF) 可以重新编程哪些 mRNA 可用并翻译以产生不同水平的 在真菌物种中，翻译控制发挥着响应离散细胞信号的编码蛋白质。 在宿主逃避和其他发病机制以及哺乳动物物种中发挥重要作用， eIF 水平的改变和修饰会影响癌症进展和其他疾病状态。 许多蛋白质因子刺激翻译，包括 eIF4 因子（4A、B、E、G 和 H） 接合 mRNA 的 5' 帽和核糖体的小亚基，在事件开始前促进事件发生 大量数据支持 RNA 解旋酶 4A 和辅因子 4B 和 4G 在中的作用。 解开 5’UTR 以促进结构化 mRNA 的翻译。 4B 翻译活动与严重依赖 4G 的翻译活动不同，尽管这两个因素 此外，与促肿瘤 4A 和 4G 形成鲜明对比的是，增加了 4A 的水平。 4B 改善了侵袭性癌症患者的生存率，初步数据直接表明 4B 了解 4B 如何介导 4B 的翻译。 特定转录本对于理解和预测转移表型可能很重要。 最后，已知 eIF4 因子的翻译后修饰可调节翻译 哺乳动物中，放松管制在疾病状态下很常见，但目前尚不清楚这些变化是如何发生的。 eIF4 因子调节真菌物种的翻译以及它如何影响特定的表达 该提案投入了多年的表征经验，应对这些挑战。 酵母翻译起始的机制以及强大的体外、遗传和基因组库 为了更好地了解核糖体如何选择 mRNA 进行翻译， 这项工作的目标是了解 4B 如何实现翻译而不是压制 我们将追求三个目标： 目标 1. 确定 4F 和 4B 的作用方式。 相互作用影响 4B 高依赖性和低依赖性 mRNA 的翻译 目标 2. 阐明酵母 4B-。 目标 3. 了解 4F 和 4F 的翻译后修饰 (PTM) 是如何进行的。 4B 影响 4B 特异性 mRNA 控制 该提案将使用 eIF4B 作为模型来确定如何核心。 翻译起始因子调节特定 mRNA 库的翻译与抑制，并且会 阐明 4B 的强大活性如何对抗转移表型。