Identification of stop codon readthrough genes in Saccharomyces cerevisiae.
Identification of stop codon readthrough genes in Saccharomyces cerevisiae.
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DOI：
10.1093/nar/gkg330
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发表时间：
2003-05-01
影响因子：
14.9
通讯作者：
Rousset JP
中科院分区：
文献类型：
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作者：
Namy O;Duchateau-Nguyen G;Hatin I;Hermann-Le Denmat S;Termier M;Rousset JP
我们专门寻找酵母基因组内由一种涉及终止密码子的非常规翻译机制所控制的基因。出于这个原因，我们利用酵母数据库的基因组区域设计了一个计算机程序，寻找仅由一个独特终止密码子分隔的两个相邻开放阅读框（称为SORF）。在鉴定出的58个SORF中，有8个显示出终止密码子通读水平在3%到25%之间。对于这8个序列中的每一个，我们都证明了存在多聚腺苷酸（poly(A)）信使核糖核酸（mRNA）。利用同基因的[PSI +]和[psi -]酵母菌株，我们表明对于其中两个序列，所使用的机制是一种真正的通读。然而，其余6个序列对PSI状态不敏感，这表明要么是一种独立于eRF3的翻译终止过程，要么是一种新的终止密码子通读机制。我们的结果表明，在一个大的开放阅读框中存在终止密码子可能并不总是对应于测序错误或假基因，而可能是一个功能基因中的重编码信号。这强调了基因组注释应该考虑到重编码信号可能比以前预期的更频繁被使用这一事实。
We specifically sought genes within the yeast genome controlled by a non-conventional translation mechanism involving the stop codon. For this reason, we designed a computer program using the yeast database genomic regions, and seeking two adjacent open reading frames separated only by a unique stop codon (called SORFs). Among the 58 SORFs identified, eight displayed a stop codon bypass level ranging from 3 to 25%. For each of the eight sequences, we demonstrated the presence of a poly(A) mRNA. Using isogenic [PSI+] and [psi–] yeast strains, we showed that for two of the sequences the mechanism used is a bona fide readthrough. However, the six remaining sequences were not sensitive to the PSI state, indicating either a translation termination process independent of eRF3 or a new stop codon bypass mechanism. Our results demonstrate that the presence of a stop codon in a large ORF may not always correspond to a sequencing error, or a pseudogene, but can be a recoding signal in a functional gene. This emphasizes that genome annotation should take into account the fact that recoding signals could be more frequently used than previously expected.