Translational control by the eIF4 factors

eIF4 因子的翻译控制

• 批准号: 9116458
• 负责人: Sarah Elizabeth Walker
• 金额: $ 24.9万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9116458
• 关键词: Affect; Alanine; Aspartate; Award; Binding; Biological Assay; Cancer Etiology; Cells; Codon Nucleotides; Complex; Data; Defect; Disease; Early identification; Early treatment; Elements; Eukaryotic Cell; Eukaryotic Initiation Factors; Event; Faculty; Fluorescence Resonance Energy Transfer; Future; Gene Expression; Genetic Translation; Global Change; Goals; Growth; Head; Health; Heart Diseases; In Vitro; Lead; Learning; Link; Malignant Neoplasms; Mentors; Messenger RNA; Molecular; Monitor; Movement; Mutation; Outcome; Peptide Initiation Factors; Phenotype; Phosphorylation; Positioning Attribute; Process; Protein Biosynthesis; Protein Isoforms; Proteins; RNA-Binding Proteins; Recruitment Activity; Regulation; Research Personnel; Resources; Ribosomal Proteins; Ribosomes; Role; Site; Staging; System; Techniques; Testing; Time; Translating; Translation Initiation; Translations; Work; Yeasts; base; cofactor; developmental disease; eIF-4B; human disease; insight; messenger ribonucleoprotein; nervous system disorder; reconstitution; response; skills

DESCRIPTION (provided by applicant): Controlling gene expression at the level of translation allows cells to respond rapidly and precisely to internal and external changes, and defects in this process can have dire consequences. Cancer, heart disease, and other developmental and neurological disorders have been linked to defects in phosphorylation cascades that are responsible for modifying eukaryotic translation initiation factors (eIFs) and actuating global changes in translation efficiency and in the translation of specific mRNAs, yet the molecular outcome of these phosphorylation events is not understood in most cases. The long-term goal of our work is to understand the molecular basis for translational control at the level of mRNA recruitment to the ribosomal translation preinitiation complex (PIC). By further investigating how phosphorylation of eIFs changes the efficiency of translation, we will make insights into the basic molecular mechanisms underlying the etiology of cancer and other diseases. During translation initiation, eIFs and other factors interact within the PIC and elements of mRNAs to determine what mRNAs are translated. We have reconstituted translation initiation in vitro from purified yeast components and made important findings regarding the roles of eIF4B and eIF4F in promoting the mRNA recruitment step. We demonstrated that eIF4B binds directly to the ribosome, and promotes functional interaction of eIF4F with the initiation machinery to promote mRNA recruitment to the PIC, challenging the previously held view that eIF4B acts as an RNA-binding protein to activate mRNAs for translation. We also have evidence that eIF4G interacts with the PIC in an mRNA-independent manner. This leads us to hypothesize that rather than activating mRNPs independently of the ribosome as has been suggested, the eIF4 factors bind to the PIC to form a holoPIC that directly recruits and unwinds mRNA. To investigate this possibility, and to understand the basic system in place for recruiting mRNAs, we will characterize the interactions of the eIF4 factors with the PIC. We will then ask what happens to these interactions and assess the resulting changes in translation and phenotype when the eIF4 factors are phosphorylated. In the future this will allow me to ask additional important questions about the mRNAs that are translated in response to single phosphorylation events and how the general translation initiation machinery is modified to allow translational control of specific mRNAs, distinguishing me from my mentor, Jon Lorsch. In the course of pursuing these questions, I will gain new skills and set up an exciting project that will make me a more competitive candidate for faculty positions. The award would provide the resources to help me achieve my goal of becoming an independent researcher, and allow me to acquire preliminary data for a successful R01 application more quickly.

描述（由申请人提供）：在翻译水平上控制基因表达可以使细胞对内部和外部的变化做出快速而精确的反应，而这个过程中的缺陷可能会产生可怕的后果。癌症、心脏病以及其他发育和神经系统疾病与磷酸化级联缺陷有关，磷酸化级联负责修饰真核翻译起始因子 (eIF) 并驱动翻译效率和特定 mRNA 翻译的整体变化，但分子结果在大多数情况下，这些磷酸化事件的发生机制尚不清楚。我们工作的长期目标是了解核糖体翻译前起始复合物（PIC）招募 mRNA 水平上翻译控制的分子基础。通过进一步研究 eIF 的磷酸化如何改变翻译效率，我们将深入了解癌症和其他疾病病因学的基本分子机制。在翻译起始过程中，eIF 和其他因素在 PIC 和 mRNA 元件内相互作用，以确定翻译哪些 mRNA。我们利用纯化的酵母成分在体外重建了翻译起始，并就 eIF4B 和 eIF4F 在促进 mRNA 募集步骤中的作用取得了重要发现。我们证明，eIF4B 直接与核糖体结合，并促进 eIF4F 与起始机制的功能相互作用，从而促进 mRNA 募集到 PIC，这挑战了之前认为 eIF4B 作为 RNA 结合蛋白来激活 mRNA 进行翻译的观点。我们还有证据表明 eIF4G 以不依赖于 mRNA 的方式与 PIC 相互作用。这使我们推测，eIF4 因子与 PIC 结合形成直接招募和解旋 mRNA 的 HoloPIC，而不是像所建议的那样独立于核糖体激活 mRNP。为了研究这种可能性，并了解招募 mRNA 的基本系统，我们将描述 eIF4 因子与 PIC 的相互作用。然后我们将询问这些相互作用会发生什么，并评估当 eIF4 因子磷酸化时翻译和表型的变化。将来，这将使我能够提出更多关于响应单一磷酸化事件而翻译的 mRNA 的重要问题，以及如何修改一般翻译起始机制以允许特定 mRNA 的翻译控制，这将我与我的导师 Jon Lorsch 区分开来。在追求这些问题的过程中，我将获得新技能并建立一个令人兴奋的项目，这将使我成为更有竞争力的教师职位候选人。该奖项将提供资源帮助我实现成为一名独立研究员的目标，并让我更快地获取成功 R01 申请的初步数据。