We describe a novel approach to separate two ribosome populations from the same cells and use this method in combination with RNA-seq to identify mRNAs bound to Saccharomyces cerevisiae ribosomes with and without Rps26, a protein linked to the pathogenesis of Diamond–Blackfan anemia (DBA). These analyses reveal that Rps26 contributes to mRNA-specific translation by recognition of the Kozak sequence in well-translated mRNAs and that Rps26-deficient ribosomes preferentially translate mRNA from select stress-response pathways. Surprisingly, exposure of yeast to these stresses leads to the formation of Rps26-deficient ribosomes and to the increased translation of their target mRNAs. These results describe a novel paradigm: the production of specialized ribosomes, which play physiological roles in augmenting the well-characterized transcriptional stress response with a heretofore unknown translational response, thereby creating a feed-forward loop in gene expression. Moreover, the simultaneous gain-of-function and loss-of-function phenotypes from Rps26-deficient ribosomes can explain the pathogenesis of DBA.

中文翻译：

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Rps26通过识别Kozak序列元件指导mRNA特异性翻译

我们描述了一种从同一细胞中分离出两个核糖体群体的新颖方法，并将该方法与RNA-seq结合使用以鉴定与酿酒酵母结合的mRNA。带有和不带有Rps26的核糖体，Rps26是一种与Diamond–Blackfan贫血（DBA）发病机理有关的蛋白质。这些分析表明，Rps26通过识别良好翻译的mRNA中的Kozak序列而有助于mRNA特异性翻译，而Rps26缺失的核糖体则优先从选择的应激反应途径翻译mRNA。出乎意料的是，酵母暴露于这些压力导致形成Rps26缺陷的核糖体，并导致其靶mRNA的翻译增加。这些结果描述了一种新的范例：特殊核糖体的产生，该核糖体在以迄今未知的翻译反应增强众所周知的转录应激反应中发挥生理作用，从而在基因表达中产生前馈环。而且，