Unraveling the mechanism by which Rps26-deficient ribosomes form to support the stress response

揭示 Rps26 缺陷核糖体形成支持应激反应的机制

• 批准号: 10226865
• 负责人: Jason Yoon-Mo Yang
• 金额: $ 5.01万
• 依托单位: SCRIPPS FLORIDA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2022-04-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10226865
• 关键词: Alanine; Amino Acids; Binding; Cells; Congenital Abnormality; Data; Destinations; Development; Diamond-Blackfan anemia; Disease; Dissociation; Ensure; Etiology; Excision; Failure; Genetic Translation; Heterogeneity; In Vitro; Individual; Life; Lifting; Link; Malignant Neoplasms; Marrow; Messenger RNA; Modification; Molecular Chaperones; Mutation; Organism; Outcome; Pathway interactions; Phenotype; Phosphorylation; Phosphotransferases; Physiologic pulse; Physiological; Population; Positioning Attribute; Post-Translational Protein Processing; Production; Protein Biosynthesis; Protein Deficiency; Proteins; Quality Control; Recombinants; Reporting; Ribosomal Proteins; Ribosomal RNA; Ribosomes; Risk; Role; Series; Sodium Chloride; Specificity; Stress; Testing; Translating; Translations; Work; Yeasts; biological adaptation to stress; bone; cancer cell; cost; design; experimental study; human disease; in vivo; interest; macromolecule; mimetics; novel; null mutation; preference; programs; proteostasis; repaired; response

Project Summary/Abstract Recently ribosome subpopulations that differ in their composition, lacking individual ribosomal proteins (RPs), or containing specific modifications have garnered a lot of interest. In the case of RP content, multiple studies have shown that ribosomes lacking specific RPs are present in cells, including ribosomes deficient in Rps26. While their physiological relevance remains unclear in most cases, the Karbstein lab has recently demonstrated that ribosomes lacking Rps26 are produced specifically under high salt and pH stress to enable the preferential translation of mRNAs encoding proteins from the Hog1 and Rim101 pathways that are required for the response to these stresses. This change in mRNA specificity between Rps26-containing and deficient ribosomes arises from the recognition of the -4 position of the Kozak sequence by Rps26, thereby supporting the translation of well-translated mRNAs by Rps26-containing ribosomes in rich medium, and the translation of specific mRNAs in the Hog1 and Rim101 pathways by Rps26-deficient ribosomes that are formed under these stresses. What remains unknown is how Rps26-deficient ribosomes form under high salt and high pH stress. My preliminary results suggest Rps26-deficient ribosomes are produced by release of Rps26 from pre-existing ribosomes. Therefore, I will further dissect in more detail the mechanism that leads to the production of Rps26- deficient ribosomes, exploring the role of the Rps26-specific chaperone Tsr2 in delivering to and extracting Rps26 from ribosomes (Aim1), and testing which posttranslational modifications regulate this pathway (Aim2). Next, I will test if Rps26 is (re-) incorporated into Rps26-deficient ribosomes, to allow for a rapid switch in mRNA-specificity without the costs of re-building new ribosomes, or whether instead these ribosomes are degraded (Aim3). Together, these experiments will clarify how Rps26-deficient ribosomes form under stress. In addition to further expanding on this novel paradigm of stress-induced production of a specific ribosome population, the results will also have implications for the development of diseases linked to Rps26-deficiency, such as Diamond- Blackfan anemia. Because the etiology of 10-15% of all cases remains unknown, and is not linked to RP- deficiency, it is possible that overactivation of pathways leading to the release of RPs such as Rps26 might be responsible for a subset of cases, similar to the subset of cases caused by deficiency of the Rps26-chaperone Tsr2. Furthermore, ribosomes lacking individual RPs, including Rps26, are produced in cancer cells, where they are associated with poor outcomes. Thus, this work will also help delineate how cancer cells modulate the translational machinery to subvert translation to its purposes.

项目摘要/摘要 最近缺乏个体核糖体蛋白（RPS）的核糖体亚群，其组成不同 或包含特定的修改引起了很多兴趣。对于RP含量，多个研究 已经表明，细胞中存在缺乏特定RP的核糖体，包括RPS26中缺乏的核糖体。 尽管在大多数情况下它们的生理相关性尚不清楚，但Karbstein实验室最近有 证明缺乏RPS26的核糖体是在高盐和pH胁迫下专门产生的，以实现 从HOG1和RIM101途径中编码蛋白质的mRNA的优先翻译 为了对这些压力的反应。含RPS26和不足之间的mRNA特异性的这种变化 核糖体来自RPS26对Kozak序列的-4位置的识别，从而支持 通过富含RPS26的核糖体在富含RPS26的核糖体中翻译良好的mRNA，然后翻译 RPS26缺陷核糖体在HOG1和RIM101途径中的特定mRNA，这些核糖体在这些核糖体下形成 压力。 尚不清楚的是如何在高盐和高pH应激下形成RPS26缺陷核糖体。我的 初步结果表明RPS26缺陷核糖体是通过从预先存在的 核糖体。因此，我将进一步详细阐述导致RPS26-产生的机制。 核糖体不足，探索RPS26特异性伴侣TSR2在传递和提取中的作用 核糖体（AIM1）的RPS26，并测试哪种翻译后修饰调节该途径（AIM2）。 接下来，我将测试RPS26是否（重新）并入RPS26缺陷核糖体中，以允许快速切换 mRNA特异性没有重建新核糖体的成本，或者这些核糖体是否为 退化（AIM3）。 这些实验将共同阐明在应力下如何形成RPS26缺陷核糖体。除了进一步 扩大了这种新颖的应激引起的特定核糖体种群产生的范式，结果 还将对与RPS26缺陷相关的疾病的发展有影响，例如钻石 - 黑凡贫血。因为所有病例中有10-15％的病因尚不清楚，并且与RP-无关 不足，导致RPS（例如RPS26）释放的途径的过度激活可能是 负责一部分案件，类似于RPS26-Chaperone缺乏引起的病例子集 TSR2。此外，在癌细胞中产生缺乏包括RPS26在内的单个RP的核糖体，其中 它们与不良的结果有关。因此，这项工作还将有助于描述癌细胞如何调节 翻译机械将翻译成其目的。