Autogenous translational regulation of the Borna disease virus negative control factor X from polycistronic mRNA using host RNA helicases.
Autogenous translational regulation of the Borna disease virus negative control factor X from polycistronic mRNA using host RNA helicases.
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DOI：
10.1371/journal.ppat.1000654
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发表时间：
2009-11
期刊：
影响因子：
6.7
通讯作者：
Tomonaga K
中科院分区：
文献类型：
--
作者：
Watanabe Y;Ohtaki N;Hayashi Y;Ikuta K;Tomonaga K
博尔纳病病毒（Borna disease virus，BDV）是一种非节段性负链RNA病毒，它采用多种独特的基因表达策略。BDV最短的转录本X/P mRNA编码至少3个开放阅读框（ORF）：上游ORF（uORF）、X和5′至3′方向的P。X是病毒聚合酶活性的负调节因子，而P磷蛋白是聚合酶复合物的必要辅因子，这表明X的翻译受到严格控制，这取决于病毒复制。然而，X/P多顺反子mRNA使用的翻译机制尚未详细确定。在这里，我们证明了X/P mRNA通过与宿主因子的相互作用自发地调节X的翻译。瞬时转染X/P mRNA对应的cDNA克隆显示，X ORF主要通过uORF终止偶联的再起始进行翻译，其效率被P的表达上调。我们发现，P可能通过干扰X/P mRNA 5′非翻译区的磷酸化，抑制DEAD盒RNA解旋酶DDX 21与X/P mRNA 5′非翻译区的相互作用，从而增强X ORF处的核糖体再起始。我们的研究结果不仅证明了一个独特的病毒调节蛋白的翻译控制，但也阐明了一个以前未知的机制，利用RNA解旋酶调节多顺反子mRNA的翻译。所有病毒都依赖宿主细胞因子来完成其生命周期。因此，病毒的复制策略不仅可以提供对病毒致病机制的理解，而且可以提供有用的模型来解开宿主细胞的复杂机制。病毒mRNA的翻译调控就是一个很好的例子。博尔纳病病毒（Borna disease virus，BDV）是一种高度嗜神经的RNA病毒，以持续感染为特征。BDV以多顺反子编码转录物的形式表达mRNA。其中，0.8 kb的X/P mRNA编码至少三个开放阅读框（ORF），上游ORF，X，和P。虽然BDV X和P在病毒聚合酶活性方面具有相反的作用，但X/P多顺反子mRNA的翻译调控尚未阐明。在这项研究中，我们展示了一种利用宿主因子翻译控制病毒调节蛋白的巧妙策略。我们证明宿主RNA解旋酶（主要是DDX 21）可以通过与X/P mRNA的5′非翻译区（UTR）相互作用来影响X的核糖体再起始，下游P蛋白通过干扰DDX 21与5′ UTR的结合来自体控制X的翻译。我们的研究结果不仅揭示了一个独特的病毒调节蛋白的翻译控制，但也是一个以前未知的机制，使用RNA解旋酶的多顺反子mRNA的翻译调节。
Borna disease virus (BDV) is a nonsegmented, negative-strand RNA virus that employs several unique strategies for gene expression. The shortest transcript of BDV, X/P mRNA, encodes at least three open reading frames (ORFs): upstream ORF (uORF), X, and P in the 5′ to 3′ direction. The X is a negative regulator of viral polymerase activity, while the P phosphoprotein is a necessary cofactor of the polymerase complex, suggesting that the translation of X is controlled rigorously, depending on viral replication. However, the translation mechanism used by the X/P polycistronic mRNA has not been determined in detail. Here we demonstrate that the X/P mRNA autogenously regulates the translation of X via interaction with host factors. Transient transfection of cDNA clones corresponding to the X/P mRNA revealed that the X ORF is translated predominantly by uORF-termination-coupled reinitiation, the efficiency of which is upregulated by expression of P. We found that P may enhance ribosomal reinitiation at the X ORF by inhibition of the interaction of the DEAD-box RNA helicase DDX21 with the 5′ untranslated region of X/P mRNA, via interference with its phosphorylation. Our results not only demonstrate a unique translational control of viral regulatory protein, but also elucidate a previously unknown mechanism of regulation of polycistronic mRNA translation using RNA helicases. All viruses rely on host cell factors to complete their life cycles. Therefore, the replication strategies of viruses may provide not only the understanding of virus pathogenesis but also useful models to disentangle the complex machinery of host cells. Translation regulation of viral mRNA is a good example of this. Borna disease virus (BDV) is a highly neurotropic RNA virus which is characterized by persistent infection. BDV expresses mRNAs as polycistronic coding transcripts. Among them, the 0.8 kb X/P mRNA encodes at least three open reading frames (ORFs), upstream ORF, X, and P. Although BDV X and P have opposing effects in terms of viral polymerase activity, the translational regulation of X/P polycistronic mRNA has not been elucidated. In this study, we show an ingenious strategy of translational control of viral regulatory protein using host factors. We demonstrate that host RNA helicases, mainly DDX21, can affect ribosomal reinitiation of X via interaction with the 5′ untranslated region (UTR) of X/P mRNA and that the downstream P protein autogenously controls the translation of X by interfering with the binding of DDX21 to the 5′ UTR. Our findings uncover not only a unique translational control of viral regulatory protein but also a previously unknown mechanism of translational regulation of polycistronic mRNA using RNA helicases.
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DOI：
10.1083/jcb.108.2.229
发表时间：
1989-02
期刊：
The Journal of cell biology
影响因子：
--
作者：
Kozak M
通讯作者：
Kozak M
影响因子：
14.9
作者：
Fuller-Pace FV
通讯作者：
Fuller-Pace FV
影响因子：
5.3
作者：
Kojima, KK;Matsumoto, T;Fujiwara, H
通讯作者：
Fujiwara, H
影响因子：
5.4
作者：
CUBITT, B;OLDSTONE, C;DELATORRE, JC
通讯作者：
DELATORRE, JC
影响因子：
3.5
作者：
Iacono, M;Mignone, F;Pesole, G
通讯作者：
Pesole, G