Misdecoding of Rare CGA Codon by Translation Termination Factors, eRF1/eRF3, Suggests Novel Class of Ribosome Rescue Pathway in S. cerevisiae
Misdecoding of Rare CGA Codon by Translation Termination Factors, eRF1/eRF3, Suggests Novel Class of Ribosome Rescue Pathway in S. cerevisiae
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翻译终止因子 eRF1/eRF3 对稀有 CGA 密码子的错误解码表明酿酒酵母中存在新型核糖体救援途径
DOI：
10.1111/febs.14709
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Koichi Ito
中科院分区：
文献类型：
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作者：
Miki Wada;Koichi Ito
CGA精氨酸密码子在酿酒酵母中是一种罕见的密码子。因此，来自具有内部CGA密码子重复的报告基因的全长成熟蛋白质合成显著减少，并且报告基因反而通过未知机制产生短尺寸多肽。考虑到CGA正义密码子和UGA终止密码子之间的产物大小和相似性质，我们假设真核生物多肽链释放因子复合物eRF 1/eRF 3催化CGA重复序列处的多肽释放。在此，我们进行了一系列的分析和报告，CGA密码子可以在一定程度上，在酵母中作为终止密码子解码。这也提出了一个有趣的可能性，翻译终止因子eRF 1/eRF 3拯救核糖体停滞在CGA密码子，释放过早的多肽，并与典型的tRNAICG竞争CGA密码子。我们的研究结果表明，在真核生物的替代核糖体拯救途径。目前的结果表明，低效率密码子的错误解码可能在酿酒酵母的整体翻译调控中发挥新的作用。
The CGA arginine codon is a rare codon inSaccharomyces cerevisiae. Thus, full‐length mature protein synthesis from reporter genes with internal CGA codon repeats are markedly reduced, and the reporters, instead, produce short‐sized polypeptides via an unknown mechanism. Considering the product size and similar properties between CGA sense and UGA stop codons, we hypothesized that eukaryote polypeptide‐chain release factor complex eRF1/eRF3 catalyses polypeptide release at CGA repeats. Herein, we performed a series of analyses and report that the CGA codon can be, to a certain extent, decoded as a stop codon in yeast. This also raises an intriguing possibility that translation termination factors eRF1/eRF3 rescue ribosomes stalled at CGA codons, releasing premature polypeptides, and competing with canonical tRNAICGto the CGA codon. Our results suggest an alternative ribosomal rescue pathway in eukaryotes. The present results suggest that misdecoding of low efficient codons may play a novel role in global translation regulation inS. cerevisiae.