Mechanisms of Translation Control in Humans

摘要 蛋白质的合成，或翻译，在所有生命形式中将基因型与表型联系起来。凯特实验室 长期以来对蛋白质合成机制的兴趣，从细菌中收集到的普遍原则， 翻译是人类翻译调节的基础。这个应用程序解决了一些基本问题 关于翻译在人类中是如何被调节的。我们打算探讨在细胞内翻译起始的调控， 特定的细胞和组织，以及影响翻译速度和准确性的翻译延伸机制。 核糖体我们认为这两条广泛的研究路线将导致许多关于蛋白质合成的发现 最终可以用来治疗人类疾病。 真核生物翻译起始的经典机制涉及许多一般的翻译起始 因素我们最近发现，其中之一--真核起始因子3（eIF 3）--具有特殊的作用， 激活或抑制特定mRNA的翻译。我们还发现，eIF 3意外地包括 其自身的5 '-m7 G帽结合亚基。在本申请中，我们将探讨eIF 3如何以及何时执行其特定的 监管职能。我们将使用分子和结构的方法来破译eIF 3和反式作用 因子与结构化RNA元件相互作用以调节特定mRNA的翻译。我们还将 研究eIF 3在调节活化T细胞翻译中的作用。最后，我们将确定eIF 3 T细胞受体翻译的调节影响T细胞发育。这些问题的答案将揭示 对翻译控制的基本见解，并将为未来的工程改进提供基础 细胞免疫疗法 许多人类疾病的蛋白质靶点由于其潜在的生化功能而仍然是“不可用药的” 和行为。小分子药物发现的这些限制阻碍了开发负担得起的药物的希望。 治疗学我们最近发现，结合核糖体的小分子可以选择性地阻止 翻译人类蛋白质，揭示了一种全新的作用机制，可以使靶向 以前“不可药用”的蛋白质。这些药物样化合物直接和选择性地调节翻译 在翻译延伸或终止过程中的特定新生多肽。我们还发现了这些化合物 影响核糖体质量控制途径。我们将探讨是否采用类似的机制， 细胞代谢物来调节特定mRNA的翻译。我们还将绘制新的核糖体质量 控制靶向翻译移码的途径，这是一个对翻译过程所采用的机制敏感的过程。 类似药物的化合物来选择性地阻止翻译。综合起来，这些实验将提供新的 分子的见解，可以帮助设计新的小分子调节剂的人类翻译。

ABSTRACT Protein synthesis, or translation, connects genotype to phenotype in all forms of life. The Cate lab has a longstanding interest in the mechanisms of protein synthesis, from universal principles gleaned from bacterial translation to the basis of translation regulation in humans. This application tackles fundamental questions about how translation is regulated in humans. We propose to explore the regulation of translation initiation in specific cells and tissues, and mechanisms of translation elongation that affect the speed and accuracy of the ribosome. We think these two broad lines of investigation will lead to many discoveries about protein synthesis that could eventually be leveraged to treat human disease. The canonical mechanism of translation initiation in eukaryotes involves many general translation initiation factors. We recently discovered that one of these–eukaryotic initiation factor 3 (eIF3)–serves specialized roles to either activate or repress the translation of specific mRNAs. We also found that eIF3 unexpectedly includes its own 5’-m7G cap binding subunit. In this application, we will probe how and when eIF3 carries out its specific regulatory functions. We will use molecular and structural approaches to decipher how eIF3 and trans-acting factors interact with structured RNA elements to regulate the translation of specific mRNAs. We will also examine the role of eIF3 in regulating translation in activated T cells. Finally, we will determine how eIF3 regulation of T cell receptor translation affects T cell development. Answers to these questions will reveal fundamental insights into translational control and will provide a foundation for future engineering of improved cell-based immunotherapies. Protein targets for many human diseases remain “undruggable” due to their underlying biochemical functions and behavior. These limits to small molecule drug discovery hold back the promise of developing affordable therapeutics. We recently showed that small molecules that bind the ribosome can selectively stall the translation of human proteins, revealing an entirely new mechanism of action that could enable targeting previously “undruggable” proteins. These drug-like compounds directly and selectively modulate the translation of specific nascent polypeptides during translation elongation or termination. We also found these compounds impact ribosome quality control pathways. We will explore whether similar mechanisms are employed by cellular metabolites to regulate the translation of specific mRNAs. We will also map new ribosome quality control pathways that target translation frameshifting, a process sensitive to the mechanisms employed by the drug-like compounds to selectively stall translation. Taken together, these experiments will provide new molecular insights that could aid in the design of new small molecule modulators of human translation.