Quantification of elongation stalls and impact on gene expression in yeast.
Quantification of elongation stalls and impact on gene expression in yeast.
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酵母中延伸停滞的量化及其对基因表达的影响。
DOI：
10.1101/2023.03.19.533377
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Zid,BrianM
中科院分区：
文献类型：
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作者：
Hou,Wanfu;Harjono,Vince;Harvey,AlexT;Subramaniam,ArvindRasi;Zid,BrianM
核糖体停顿是包括蛋白质折叠和定位在内的共翻译事件的关键部分。然而，延长的核糖体暂停可导致核糖体碰撞，导致核糖体拯救途径的激活和蛋白质和mRNA的周转。虽然这种关系已经知道，有很少的探索如何核糖体失速影响翻译持续时间在定量水平上。我们已经采取了一种用于测量伸长时间的方法，并将其用于酵母菌以量化伸长失速的影响。我们发现，在含有Arg CGA密码子重复诱导的失速，Hel2介导的蛋白质表达和mRNA水平的剂量依赖性降低和延长延迟分钟的顺序的成绩单。在含有同义取代非最佳Leu密码子的转录本中，蛋白质和mRNA水平降低，以及类似的延长延迟，但这是通过非Hel2介导的机制发生的。最后，我们发现Dhh1选择性地增加蛋白质表达，mRNA水平和延伸率。这表明，不同的翻译不良的mRNA将激活不同的救援途径，尽管相似的延长停滞持续时间。两者合计，这些结果提供了新的定量机制洞察翻译的监督和Hel2和Dhh1介导的核糖体暂停事件的作用。
Ribosomal pauses are a critical part of cotranslational events including protein folding and localization. However, extended ribosome pauses can lead to ribosome collisions, resulting in the activation of ribosome rescue pathways and turnover of protein and mRNA. While this relationship has been known, there has been little exploration of how ribosomal stalls impact translation duration at a quantitative level. We have taken a method used to measure elongation time and adapted it for use inSaccharomyces cerevisiaeto quantify the impact of elongation stalls. We find, in transcripts containing Arg CGA codon repeat-induced stalls, a Hel2-mediated dose-dependent decrease in protein expression and mRNA level and an elongation delay on the order of minutes. In transcripts that contain synonymous substitutions to nonoptimal Leu codons, there is a decrease in protein and mRNA levels, as well as similar elongation delay, but this occurs through a non-Hel2-mediated mechanism. Finally, we find that Dhh1 selectively increases protein expression, mRNA level, and elongation rate. This indicates that distinct poorly translated mRNAs will activate different rescue pathways despite similar elongation stall durations. Taken together, these results provide new quantitative mechanistic insight into the surveillance of translation and the roles of Hel2 and Dhh1 in mediating ribosome pausing events.