Transcription and replication of nonsegmented negative-strand RNA viruses.
Transcription and replication of nonsegmented negative-strand RNA viruses.
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DOI：
10.1007/978-3-662-06099-5_3
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发表时间：
2004
影响因子：
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通讯作者：
S. Whelan;J. Barr;G. Wertz
中科院分区：
文献类型：
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作者：
S. Whelan;J. Barr;G. Wertz
单病毒目的非节段负链（NNS） RNA病毒包括各种各样的人类、动物和植物病原体。这些病毒的NNS RNA基因组是两种不同RNA合成过程的模板：转录产生mrna和通过产生正义反基因组作为模板产生后代负链基因组的基因组复制。单病毒中的四个病毒科都通过转录离散的亚基因组mrna来表达其基因组中编码的信息。NNS RNA病毒转录控制的关键特征是病毒编码的RNA依赖RNA聚合酶在单个3 '近端位点进入，随后是线性基因阵列的强制性顺序转录。基因表达水平主要受每个基因相对于单个启动子的位置以及位于每个基因的开始和结束以及基因间连接处的顺式作用序列的调节。强制性顺序转录表明，上游基因的终止是下游基因启动所必需的。因此，终止是在单个转录启动子框架内调节单个基因表达的一种手段。通过对整个病毒基因组或亚基因组复制子衍生物进行工程设计，已经确定了信号转录物起始、5 ‘端修饰、3 ’端聚腺苷酸化和转录终止的重要元件。尽管不同的NNS RNA病毒家族使用不同的序列来控制这些过程，但转录终止是控制基因表达的共同主题，整体转录调控是控制病毒感染结果的关键。讨论了控制复制和转录的最新模型。
The nonsegmented negative-strand (NNS) RNA viruses of the orderMononegaviralesinclude a wide variety of human, animal, and plant pathogens. The NNS RNA genomes of these viruses are templates for two distinct RNA synthetic processes: transcription to generate mRNAs and replication of the genome via production of a positive-sense antigenome that acts as template to generate progeny negative-strand genomes. The four virus families within theMononegaviralesall express the information encoded in their genomes by transcription of discrete subgenomic mRNAs. The key feature of transcriptional control in the NNS RNA viruses is entry of the virus-encoded RNA-dependent RNA polymerase at a single 3′ proximal site followed by obligatory sequential transcription of the linear array of genes. Levels of gene expression are primarily regulated by position of each gene relative to the single promoter and also bycis-acting sequences located at the beginning and end of each gene and at the intergenic junctions. Obligatory sequential transcription dictates that termination of each upstream gene is required for initiation of downstream genes. Therefore, termination is a means to regulate expression of individual genes within the framework of a single transcriptional promoter. By engineering either whole virus genomes or subgenomic replicon derivatives, elements important for signaling transcript initiation, 5′ end modification, 3′ end polyadenylation, and transcription termination have been identified. Although the diverse families of NNS RNA virus use different sequences to control these processes, transcriptional termination is a common theme in controlling gene expression and overall transcriptional regulation is key in controlling the outcome of viral infection. The latest models for control of replication and transcription are discussed.