Bunyavirus mRNA synthesis is coupled to translation to prevent premature transcription termination
Bunyavirus mRNA synthesis is coupled to translation to prevent premature transcription termination
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DOI：
10.1261/rna.436607
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发表时间：
2007-05-01
期刊：
影响因子：
4.5
通讯作者：
Barr, John N.
中科院分区：
文献类型：
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作者：
Barr, John N.
布尼亚病毒科成员的信使RNA转录在负链RNA病毒组中是独特的，因为它需要持续的蛋白质合成。解释这一现象的长期模型提出，翻译要求不是蛋白质产物，而是核糖体沿新生mrna易位。这种运动被认为是为了破坏虚假的转录终止信号，否则会导致mRNA过早截断，导致基因表达的致命丧失。通过将翻译终止密码子引入布尼亚病毒科的原型成员布尼亚韦拉病毒的模型RNA基因组，对该模型进行了测试。这直接表明新生mrna的翻译可以阻止转录终止。虽然这种转录和翻译的耦合在原核生物系统中很常见，但这些结果是真核细胞环境中首次报道这种强制性耦合。这些结果也提供了对布尼亚病毒终止机制的深入了解，并表明它在机制上类似于原核生物的内在终止。
Messenger RNA transcription by Bunyaviridae family members is unique within the group of negative-strand RNA viruses as it requires on-going protein synthesis. The long-standing model explaining this phenomenon proposes that the translational requirement is not for a protein product, but instead is for ribosomal translocation along nascent mRNAs. This movement is proposed to disrupt spurious transcription termination signals that otherwise cause premature mRNA truncation leading to a fatal loss of gene expression. This model was tested by introducing translational stop codons into model RNA genomes of Bunyamwera virus, the prototypic member of the Bunyaviridae family. This directly showed that translation of nascent mRNAs prevents transcription termination. While such coupling of transcription and translation is common in prokaryotic systems, these results represent the first report of such obligatory coupling in a eukaryotic cell environment. The results also provide insight into the bunyavirus termination mechanism and suggest it is mechanistically similar to prokaryotic intrinsic termination.