Widespread use of non-productive alternative splice sites in Saccharomyces cerevisiae.
Widespread use of non-productive alternative splice sites in Saccharomyces cerevisiae.
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DOI：
10.1371/journal.pgen.1004249
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发表时间：
2014-04
期刊：
影响因子：
4.5
通讯作者：
Chanfreau GF
中科院分区：
文献类型：
--
作者：
Kawashima T;Douglass S;Gabunilas J;Pellegrini M;Chanfreau GF
酿酒酵母已被用作研究前 mRNA 剪接机制的模型系统，但在该生物体中仅描述了少数选择性剪接位点使用的例子。通过对无义介导的 mRNA 衰减 (NMD) 突变株进行 RNA 测序分析，我们发现许多酿酒酵母内含子基因表现出使用可变剪接位点，但在这些位点剪接产生的许多转录本是无功能的，因为它们引入了过早的终止密码子，导致 NMD 降解。对剪接突变体与 NMD 失活相结合的分析揭示了特定剪接因子在控制这些替代剪接位点的使用中的作用，并确定了 Prp17p 在增强分支点近端上游 3' 剪接位点的使用方面的新功能，以及 Prp18p 在抑制 GCR1 中非规范 AUG 3' 剪接位点的使用方面的新功能。非生产性选择性剪接位点的使用可以在胁迫条件下以启动子依赖性方式增加，从而有助于胁迫期间基因的下调。这些结果表明，选择性剪接在酿酒酵母中很常见，但被 RNA 降解所掩盖，并且在该生物体中使用选择性剪接位点主要是为了控制转录水平，而不是增加蛋白质组多样性。准确的基因表达需要将基因信息从DNA转移到RNA。当 DNA 转录为 RNA 时，需要去除（剪接）部分 RNA 以生成遗传信息的正确副本。这个过程需要非常准确，以保存将被转移到蛋白质中的遗传信息。我们的研究表明，在面包酵母中，剪接过程并不总是产生正确的剪接产物，因为 RNA 剪接事件经常利用不正确的剪接位点。然而，这些有缺陷的 RNA 分子会通过质量控制机制从细胞中消除，以保持遗传信息的完整性。然而，错误的剪接并非毫无用处，因为它可以用来调节产生的 RNA 的数量。
Saccharomyces cerevisiae has been used as a model system to investigate the mechanisms of pre-mRNA splicing but only a few examples of alternative splice site usage have been described in this organism. Using RNA-Seq analysis of nonsense-mediated mRNA decay (NMD) mutant strains, we show that many S. cerevisiae intron-containing genes exhibit usage of alternative splice sites, but many transcripts generated by splicing at these sites are non-functional because they introduce premature termination codons, leading to degradation by NMD. Analysis of splicing mutants combined with NMD inactivation revealed the role of specific splicing factors in governing the use of these alternative splice sites and identified novel functions for Prp17p in enhancing the use of branchpoint-proximal upstream 3′ splice sites and for Prp18p in suppressing the usage of a non-canonical AUG 3′-splice site in GCR1. The use of non-productive alternative splice sites can be increased in stress conditions in a promoter-dependent manner, contributing to the down-regulation of genes during stress. These results show that alternative splicing is frequent in S. cerevisiae but masked by RNA degradation and that the use of alternative splice sites in this organism is mostly aimed at controlling transcript levels rather than increasing proteome diversity. Accurate gene expression requires the transfer of gene information from DNA to RNA. When DNA is transcribed into RNA, part of the RNA needs to be removed (spliced) to generate a proper copy of the genetic information. This process needs to be very accurate to preserve the genetic information that will be transferred into proteins. Our study shows that in baker's yeast, the splicing process does not always produce the correctly spliced products, as RNA splicing events frequently utilize incorrect splice sites. However, these deficient RNA molecules are eliminated from cells by a quality control mechanism to preserve the integrity of the genetic information. However, incorrect splicing is not useless, as it can be used to regulate the quantity of RNA that is generated.
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影响因子：
4.5
作者：
Bergkessel, Megan;Whitworth, Gregg B.;Guthrie, Christine
通讯作者：
Guthrie, Christine
影响因子：
4.5
作者：
James, SA;Turner, W;Schwer, B
通讯作者：
Schwer, B
影响因子：
64.8
作者：
Amrani, N;Ganesan, R;Jacobson, A
通讯作者：
Jacobson, A
DOI：
10.1038/nrm3454
发表时间：
2012-11
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
--
影响因子：
30.8
作者：
Mendell, JT;Sharifi, NA;Dietz, HC
通讯作者：
Dietz, HC