The Sam68 nuclear body is composed of two RNase-sensitive substructures joined by the adaptor HNRNPL.
The Sam68 nuclear body is composed of two RNase-sensitive substructures joined by the adaptor HNRNPL.
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DOI：
10.1083/jcb.201601024
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发表时间：
2016-07-04
期刊：
影响因子：
--
通讯作者：
Hirose T
中科院分区：
文献类型：
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作者：
Mannen T;Yamashita S;Tomita K;Goshima N;Hirose T
一些核体是由一个建筑RNA （arcRNA）作为结构核心形成的。在这里，Mannen等人筛选了建立在未知arcrna上的新核小体，发现Sam68核小体（SNB）由两个不同的rnase敏感亚结构组成。HNRNPL作为适配器结合两个子结构，从而形成完整的SNB。哺乳动物细胞核含有称为核体（NBs）的无膜亚细胞器。一些NBs是由一个建筑RNA （arcRNA）作为结构核心形成的。在这里，我们通过使用32,651个荧光标记的人类cDNA克隆筛选核糖核酸酶（RNase）敏感的NBs，寻找建立在未知arcRNAs上的新NBs。我们鉴定出32种标记蛋白，它们需要RNA来定位在不同的核病灶上。其中，有7种rna结合蛋白通常定位于Sam68核小体（SNB），被RNase破坏。敲除每个SNB蛋白显示SNB由两个不同的rna敏感亚结构组成。在某些条件下，一个亚结构作为独特的NB存在，称为DBC1体，而包括Sam68在内的更动态的亚结构连接形成完整的SNB。HNRNPL作为接头结合两个亚结构，并通过两组RNA识别基序与各自亚结构中假定的arcrna相互作用形成完整的SNB。
Some nuclear bodies are formed with an architectural RNA (arcRNA) as the structural core. Here, Mannen et al. screened for new nuclear bodies built on unidentified arcRNAs and found that the Sam68 nuclear body (SNB) is composed of two distinct RNase-sensitive substructures. HNRNPL acts as the adaptor to combine the two substructures, thus forming the full SNB. The mammalian cell nucleus contains membraneless suborganelles referred to as nuclear bodies (NBs). Some NBs are formed with an architectural RNA (arcRNA) as the structural core. Here, we searched for new NBs that are built on unidentified arcRNAs by screening for ribonuclease (RNase)-sensitive NBs using 32,651 fluorescently tagged human cDNA clones. We identified 32 tagged proteins that required RNA for their localization in distinct nuclear foci. Among them, seven RNA-binding proteins commonly localized in the Sam68 nuclear body (SNB), which was disrupted by RNase treatment. Knockdown of each SNB protein revealed that SNBs are composed of two distinct RNase-sensitive substructures. One substructure is present as a distinct NB, termed the DBC1 body, in certain conditions, and the more dynamic substructure including Sam68 joins to form the intact SNB. HNRNPL acts as the adaptor to combine the two substructures and form the intact SNB through the interaction of two sets of RNA recognition motifs with the putative arcRNAs in the respective substructures.