Understanding mRNA Condensation and Its Role in Translational Control during Stress

项目摘要/摘要 细胞如何动态地控制他们的蛋白质组以响应压力是 了解生物体如何对不断变化的环境做出反应。的两个有代表性的特征 细胞应激反应，这种反应在真核生物中普遍保守，发生在对各种 不同的有害环境条件是：1)细胞保护性热休克蛋白表达上调 2)RNA和蛋白质的生物分子缩合成组合体。大多数翻译都被关闭，而 参与应激反应的蛋白质被有效地产生。翻译如何重新编程以支持 热休克蛋白的转录后产生知之甚少，但生物分子缩合已经 与翻译控制有关。基本问题没有得到完全回答：1)mRNAs浓缩在哪些区域 对压力的反应？2)什么细胞机制导致了信使核糖核酸的凝聚？和3)什么是 信使核糖核酸缩合与翻译控制的功能相关性？ 在这里，我们介绍了测量&gt；5,000基因在温度下的mRNA溶解度的未发表的工作 利用生物化学沉淀法和RNA测序法对酿酒酵母进行胁迫。这些数据告诉我们 一种假说认为，阻止翻译起始通过以下方式通过特定的结合触发mRNA的缩合 未知蛋白质因素(S)。我们还预测，在应激过程中，mrna的缩合是一个适应性过程。 帮助优先翻译应激反应信息。为了检验这些假设，我们的目标是 证实阻断翻译起始触发了整个转录组和基因组上的mRNA缩合 单个消息水平，以确定mRNA凝聚所需的蛋白质因子，并测试其作用 应激过程中翻译重编程中的信使核糖核酸缩合。测定三聚氰胺溶解度的初步数据 原生和报告的mRNAs都支持阻止翻译启动触发缩合。我们有 确定并将询问一组翻译启动因素作为假定所需的候选 信使核糖核酸凝聚。我们将测试是否需要进行mrna缩合，并测量 应激过程中干扰信使核糖核酸缩合的翻译效应。 生物分子缩合物与细胞RNA动态平衡密切相关，它们的功能障碍 与几种神经退行性疾病的发病机制有关，包括阿尔茨海默氏症和帕金森氏症。 了解mRNAs如何凝聚及其在疾病发病机制中的作用 并可能为那些受影响的人提供未来的治疗方案。

Project Summary/ Abstract How cells dynamically control their proteome in response to stress is a fundamental aspect of understanding how organisms are able to react to changing environments. Two representative features of the cellular stress response, which is universally conserved across eukarya and occurs in response to a variety of different noxious environmental conditions, are 1) the upregulation of the cytoprotective heat shock proteins and 2) biomolecular condensation of RNA and protein into assemblies. Most translation is shut down, while proteins involved in the stress response are efficiently produced. How translation is reprogrammed to favor heat shock protein production post-transcriptionally is poorly understood, but biomolecular condensation has been linked to translational control. Basic questions are incompletely answered: 1) Which mRNAs condense in response to stress? 2) What cellular mechanisms are responsible for mRNA condensation? And 3) What is the functional relevance of mRNA condensation to translational control? Herein, we present unpublished work measuring mRNA solubility of >5,000 genes during temperature stress in S. cerevisiae by biochemical sedimentation followed by RNA-Sequencing. These data inform our hypothesis that blocking translation initiation triggers condensation of an mRNA through specific binding by unknown protein factor(s). We also predict that mRNA condensation during stress is an adaptive process contributing to the preferential translation of stress response messages. To test these hypotheses, we aim to confirm that blocking translation initiation triggers mRNA condensation both on a transcriptome-wide and individual message level, to determine protein factors required for mRNA condensation, and to test the role of mRNA condensation in translational reprogramming during stress. Preliminary data measuring the solubility of both native and reporter mRNAs support that blocking translation initiation triggers condensation. We have identified and will interrogate a set of the translation initiation factors as candidates putatively required for mRNA condensation. We will test whether the candidates are required for mRNA condensation and measure the translational effect of perturbing mRNA condensation during stress. Biomolecular condensates are intimately related to cellular RNA homeostasis, and their dysfunction has been linked to the pathogenesis of several neurodegenerative diseases including Alzheimer's and Parkinson's. Knowledge of how mRNAs condense and the functional role of condensation informs disease pathogenesis and may inform future treatments for those affected.