Mechanisms of Translation Regulation During Stress

摘要 蛋白质组的动态调节对于细胞存活和功能至关重要。传统上，研究人员 专注于阐明蛋白质合成，质量控制和降解的离散步骤，以了解 蛋白质组是如何形成和维持的然而，越来越多的研究表明， 翻译，质量控制和蛋白质降解途径之间的相互作用使细胞能够维持蛋白质 体内平衡（蛋白质平衡）。蛋白质稳态崩溃是衰老和衰老相关疾病的标志。 神经退行性疾病和蛋白质稳态基因的等位基因与广泛的人类神经退行性疾病相关。 遗传病因此，了解蛋白质稳态的机制， 确定新的诊断和治疗干预战略，以改善整个生命周期的健康状况。 我的研究计划将解决蛋白质质量控制因素如何相互作用和反馈调节 翻译.我们的首要目标是确定蛋白质降解因子 与翻译机器合作合成蛋白质。我们假设动态调节 mRNA翻译需要蛋白质质量控制和降解活动，以防止灾难性的 蛋白质稳定性衰竭这一假设得到了以下观察结果的支持： 蛋白酶体系统反馈（i）抑制整体翻译活性，和（ii）损害RNA- 蛋白质（RNP）颗粒，其螯合抑制性抑制的mRNA。在接下来的五年里，我的研究 小组将评估蛋白质质量控制和降解因子在介导蛋白质合成中的作用， 翻译起始、延伸的水平，并通过促进RNP的动态组装和拆卸， 颗粒。为了开始解决这一问题，我们将回答以下问题：（1）翻译是延伸吗 在蛋白质抑制应激期间差异调节？(2)蛋白质质量控制机构在以下方面的作用是什么 介导翻译起始和延伸？(3)翻译与RNP的关系是什么 颗粒？(4)蛋白质质量控制和降解因子的分子机制是什么 驱动RNP颗粒拆卸？我们将利用先进的基因组工程、光遗传学和活细胞技术， 成像策略，以确定调节人类细胞中mRNA翻译的机制， 蛋白质抑制应激源这项研究的结果将是一个空间和时间定义的地图， 蛋白质抑制应激过程中调控mRNA翻译的分子机制。这项工作的影响将是 有助于我们了解真核生物中蛋白质稳态是如何维持的， 治疗由于蛋白质稳态丧失而引起的多种人类疾病的方法。

ABSTRACT The dynamic regulation of the proteome is critical for cell survival and function. Traditionally, researchers have focused on elucidating the discrete steps of protein synthesis, quality control, and degradation to understand how the proteome is formed and maintained. Yet, a growing body of research suggests communication between translation, quality control, and protein degradation pathways enables the cell to maintain protein homeostasis (proteostasis). Proteostasis collapse is a hallmark of aging and aging-associated neurodegenerative diseases, and alleles of proteostasis genes are associated with a wide range of human genetic diseases. Therefore, understanding the mechanisms that underlie proteostasis holds promise for the identification of novel diagnostic and therapeutic intervention strategies to improve health across the lifespan. My research program will address how protein quality control factors interact and feedback to regulate translation. Our overarching goal is to determine the mechanisms by which protein degradation factors collaborate with the translational machinery to synthesize proteins. We hypothesize that the dynamic regulation of mRNA translation requires protein quality control and degradation activities to prevent catastrophic proteostatic collapse. This hypothesis is supported by the observations that inhibition of the ubiquitin- proteasome system feeds back to (i) inhibit global translation activity, and (ii) impairs the dynamics of RNA- protein (RNP) granules that sequester translationally repressed mRNAs. In the next five years, my research group will evaluate the role of protein quality control and degradation factors in mediating protein synthesis at the levels of translation initiation, elongation, and by facilitating the dynamic assembly and disassembly of RNP granules. To begin to address this problem, we will answer the following questions: (1) Is translation elongation differentially regulated during proteostatic stress? (2) What is the role of the protein quality control machinery in mediating translation initiation and elongation? (3) What is the relationship between translation and RNP granules? (4) What are the molecular mechanisms by which protein quality control and degradation factors drive RNP granule disassembly? We will leverage advanced genome engineering, optogenetics, and live cell imaging strategies to define the mechanisms that regulate mRNA translation in human cells in response to proteostatic stressors. The outcome of this research will be a spatially and temporally defined map of the molecular mechanisms governing mRNA translation during proteostatic stress. The impact of this work will be in contributing to our knowledge of how proteostasis is maintained in eukaryotes and identifying novel treatment approaches for a wide range of human diseases that arise due to loss of proteostasis.