Rab1b and ARF5 are novel RNA-binding proteins involved in FMDV IRES-driven RNA localization
Rab1b and ARF5 are novel RNA-binding proteins involved in FMDV IRES-driven RNA localization
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DOI：
10.26508/lsa.201800131
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发表时间：
2019-02-01
影响因子：
4.4
通讯作者：
Martinez-Salas, Encarnacion
中科院分区：
文献类型：
--
作者：
Fernandez-Chamorro, Javier;Francisco-Velilla, Rosario;Martinez-Salas, Encarnacion
内部核糖体进入位点（IRES）元素被组织在指导内部翻译起始的域中。在这里，我们结合蛋白质组学和成像分析来研究识别特定RNA结构子域的新型口蹄疫病毒IRES相互作用物。除了已知的小核糖核酸病毒ires结合蛋白外，我们还发现了属于RNA和蛋白质运输网络的新因子。其中，er -高尔基体的两个组分Rab1b和ARF5显示与IRES转录本直接结合。然而，Rab1b刺激了IRES功能，而ARF5则降低了IRES活性。RNA-FISH研究揭示了IRES元素的新特征。首先，IRES-RNA在细胞质内形成簇状，而cap-RNA呈分散的点状分布。其次，ires驱动的RNA定位在ARF5和Rab1b附近，但不定位在破坏高尔基体的Rab1b的显性阴性。因此，我们的数据表明IRES结构域3在富含核糖体的er -高尔基体周围的RNA定位中起作用。
Internal ribosome entry site (IRES) elements are organized in domains that guide internal initiation of translation. Here, we have combined proteomic and imaging analysis to study novel foot-and-mouth disease virus IRES interactors recognizing specific RNA structural subdomains. Besides known picornavirus IRES-binding proteins, we identified novel factors belonging to networks involved in RNA and protein transport. Among those, Rab1b and ARF5, two components of the ER-Golgi, revealed direct binding to IRES transcripts. However, whereas Rab1b stimulated IRES function, ARF5 diminished IRES activity. RNA-FISH studies revealed novel features of the IRES element. First, IRES-RNA formed clusters within the cell cytoplasm, whereas cap-RNA displayed disperse punctate distribution. Second, the IRES-driven RNA localized in close proximity with ARF5 and Rab1b, but not with the dominant-negative of Rab1b that disorganizes the Golgi. Thus, our data suggest a role for domain 3 of the IRES in RNA localization around ER-Golgi, a ribosome-rich cellular compartment.