Roles of Human elF1 in Translation Preinitiation Complex Assembly

描述（由申请人提供）：基于对酵母酵母的研究，真核翻译起始因子（elF） 5已被证明在43S预起始复合物中通过其羧基末端结构域（elF5-CTD）介导的多个结合界面的形成，在重要中间体的组装中起关键作用。该基金建议研究确定人类elF1/elF5-CTD复合体形成的结构机制，这是翻译起始前复合体组装的重要步骤。目的/假设：我们实验室的初步研究表明，elF1和elF5-CTD相互作用并形成复合物。利用核磁共振波谱，我们目前正在确定elF1/elF5-CTD配合物的相互结合界面。该授权建议进行研究，以确定elF1/elF5-CTD复合物与人类起始前复合物组分的多个结合界面。这种新型复合物介导了真核生物翻译起始过程中的一个重要步骤。为了研究elF1/elF5-CTD亚复合物在起始前复合物中的结构作用，我们将解决以下具体目标：绘制人类elF1/elF5复合体的相互结合界面并确定其结构。2.） 表征人类elF5-CTD和elF1/elF5- CTD复合物与elf2 - β和elF4G的相互作用。研究设计：为了解决elF1/elF5-CTD复合物的多重结合界面，本拨款的范围将包括核磁共振（NMR）光谱学的利用。我们将优化elF1/elF5-CTD配合物多重结合界面的核磁共振化学位移映射条件。一种涉及纯化蛋白的体外重构系统，其中一个组分是15n标记的（例如elF5-CTD），同时存在其未标记的结合伙伴（例如elF1和elf2 - β）。人类elF1/elF5复合体的多面映射将为人类翻译起始前复合体的组装提供宝贵的见解。对elF1/elF5-CTD亚复合物的结构相互作用的深入了解可能会导致未来小分子抑制剂的发展，以调节人类翻译起始，从而产生新的，强大的药物来治疗癌症。

DESCRIPTION (provided by applicant): Based on studies in yeast Saccharomyces cerevisiae, the eukaryotic translation initiation factor (elF) 5 has been shown to serve a critical role in the assembly of an important intermediate in the 43S pre-initiation complex via the formation of multiple binding interfaces mediated by its carboxyl terminal domain (elF5-CTD). This grant proposes investigations to determine the structural mechanisms involved in the formation of the human elF1/elF5-CTD complex, which is an important step in the assembly of the translation pre-initiation complex. Objective/Hypothesis: Preliminary studies in our laboratory indicate that elF1 and elF5-CTD interact and form a complex. Utilizing NMR spectroscopy, we are currently determining the mutual binding interface of the elF1/elF5-CTD complex. This grant proposes investigations to determine the multiple binding-interfaces of the elF1/elF5-CTD complex with components of the human pre-initiation complex. This novel complex mediates an important step in the eukaryotic translation initiation process. In order to investigate the structural role of the elF1/elF5-CTD sub-complex within the pre-initiation complex, we will address the following specific aims: 1.) Map the mutual binding interface of the human elF1/elF5 complex and determine its structure. 2.) Characterize the interaction of human elF5-CTD and elF1/elF5- CTD complex with elF2-beta and elF4G. Study Design: In order to tackle the multiple binding-interface of the elF1/elF5-CTD complex, the scope of this grant will encompass the utilization of nuclear magnetic resonance (NMR) spectroscopy. We will optimize conditions for NMR chemical shift mapping of the multiple binding-interface of the elF1/elF5-CTD complex. An in vitro reconstitution system involving purified proteins in which one component is 15N-labeled (e.g. elF5-CTD) while in the presence of its unlabeled binding partners (e.g. elF1 and elF2-beta). The mapping of the multiple faces of the human elF1/elF5 complex will give an invaluable insight into the assembly the human translation pre-initiation complex. Insights into the structural interactions of the elF1/elF5-CTD sub-complex could lead to the future development of small molecule inhibitors to modulate human translation initiation leading to novel, robust pharmaceutical drugs to treat cancer.