Understanding mRNA Condensation and Its Role in Translational Control during Stress

项目概要/摘要 细胞如何动态地控制它们的蛋白质组以响应压力是细胞生物学的一个基本方面。 了解生物体如何应对不断变化的环境。的两个代表性特征 细胞应激反应，这是普遍保守的真核生物，并发生在响应各种 不同的有害环境条件，是1）细胞保护性热休克蛋白的上调 和2）RNA和蛋白质的生物分子缩合成组装体。大多数翻译被关闭，而 参与应激反应的蛋白质被有效地产生。翻译如何被重新编程， 转录后热休克蛋白的产生知之甚少，但生物分子的凝聚， 与翻译控制有关。基本的问题没有得到完全的回答：1）哪些mRNA浓缩在 对压力的反应？2)什么样的细胞机制负责mRNA缩合？（3）什么是 mRNA缩合与翻译控制的功能相关性？ 在此，我们提出了未发表的工作，测量温度下>5,000个基因的mRNA溶解度， S.通过生化沉淀，然后通过RNA测序来测定酿酒酵母。这些数据告诉我们， 阻断翻译起始通过特异性结合触发mRNA缩合的假说， 未知蛋白因子。我们还预测，mRNA在应激过程中的浓缩是一个适应性过程 有助于压力反应信息的优先翻译。为了验证这些假设，我们的目标是 证实阻断翻译起始会触发mRNA在转录组范围内的缩合， 单个信息水平，以确定mRNA缩合所需的蛋白质因子，并测试 应激期间翻译重编程中的mRNA缩合。测量溶解度的初步数据 天然和报道基因mRNA都支持阻断翻译起始引发缩合。我们有 确定，并将询问一组翻译启动因素作为候选人所需的 mRNA缩合。我们将测试候选人是否需要mRNA浓缩和测量。 应激期间干扰mRNA缩合的翻译效应。 生物分子凝聚物与细胞RNA稳态密切相关，它们的功能障碍已经引起了 与包括阿尔茨海默氏症和帕金森氏症在内的几种神经退行性疾病的发病机制有关。 了解mRNA如何缩合以及缩合的功能作用有助于疾病的发病机制 并可能为受影响者的未来治疗提供信息。

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 Herein, we present unpublished work measuring mRNA solubility of 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.