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允许细胞对内部和外部变化做出快速和精确的反应，并且该过程中的缺陷可能会产生可怕的后果。癌症、心脏病和其他发育和神经系统疾病与磷酸化级联反应缺陷有关，磷酸化级联反应负责修饰真核生物翻译起始因子（eIF）并启动翻译效率和特定mRNA翻译的全局变化，但在大多数情况下，这些磷酸化事件的分子结果尚不清楚。我们工作的长期目标是了解在mRNA募集到核糖体翻译前起始复合物（PIC）水平上的翻译控制的分子基础。通过进一步研究eIFs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和其他因子在PIC和mRNA的元件内相互作用，以确定翻译哪些mRNA。我们已经重建了翻译起始在体外从纯化的酵母成分，并取得了重要的发现eIF4B和eIF4F在促进mRNA的募集步骤的作用。我们证明了eIF4B直接与核糖体结合，并促进eIF4F与起始机制的功能性相互作用，以促进mRNA募集到PIC，挑战了以前认为eIF4B作为RNA结合蛋白激活mRNA翻译的观点。我们也有证据表明eIF4G与PIC以mRNA非依赖性方式相互作用。这使我们假设，eIF4因子与PIC结合形成直接募集和解旋mRNA的holoPIC，而不是像已经提出的那样独立于核糖体激活mRNP。为了研究这种可能性，并了解募集mRNA的基本系统，我们将表征eIF4因子与PIC的相互作用。然后，我们将询问这些相互作用发生了什么，并评估eIF4因子磷酸化时翻译和表型的变化。在未来，这将使我能够提出更多重要的问题，这些问题是关于在单一磷酸化事件中翻译的mRNA，以及如何修改一般的翻译起始机制以允许特定mRNA的翻译控制，使我与我的导师Jon Lorsch区别开来。在追求这些问题的过程中，我将获得新的技能，并建立一个令人兴奋的项目，这将使我成为一个更有竞争力的候选人教师职位。该奖项将提供资源，帮助我实现成为一名独立研究人员的目标，并使我能够更快地获得成功R01应用的初步数据。