Ribonucleoprotein particles of bacterial small non-coding RNA IsrA (IS61 or McaS) and its interaction with RNA polymerase core may link transcription to mRNA fate.
Ribonucleoprotein particles of bacterial small non-coding RNA IsrA (IS61 or McaS) and its interaction with RNA polymerase core may link transcription to mRNA fate.
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DOI：
10.1093/nar/gkv1302
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发表时间：
2016-04-07
影响因子：
14.9
通讯作者：
Zenkin N
中科院分区：
文献类型：
--
作者：
van Nues RW;Castro-Roa D;Yuzenkova Y;Zenkin N
细菌中的耦合转录和翻译受到严格调控。一些小 RNA (sRNA) 通过修改核糖体访问或诱导信息降解来控制这种耦合的各个方面。在这里，我们证明sRNA IsrA（IS61或McaS）在体内和体外与RNAP的核心酶特异性结合，独立于σ因子并且远离RNAP的主要核酸结合通道。我们还表明，在细胞中，IsrA 以核糖核蛋白颗粒 (sRNP) 的形式存在，其中涉及一组确定的蛋白质，包括 Hfq、S1、CsrA、ProQ 和 PNPase。我们的研究结果表明，IsrA 可能直接参与转录，或者可以通过与转录 RNAP 的相互作用以及通过与靶标的序列互补区域将与其相关的蛋白质递送至靶 mRNA 来参与基因表达的调节。在这种类真核模型中，只有在与其靶标形成复合物的情况下，IsrA 及其相关蛋白才会变得活跃。通过这种方式，以 sRNP 的形式，细菌 sRNA 可以调节许多靶标，产生不同的结果，具体取决于相关蛋白质的集合。
Coupled transcription and translation in bacteria are tightly regulated. Some small RNAs (sRNAs) control aspects of this coupling by modifying ribosome access or inducing degradation of the message. Here, we show that sRNA IsrA (IS61 or McaS) specifically associates with core enzyme of RNAP in vivo and in vitro, independently of σ factor and away from the main nucleic-acids-binding channel of RNAP. We also show that, in the cells, IsrA exists as ribonucleoprotein particles (sRNPs), which involve a defined set of proteins including Hfq, S1, CsrA, ProQ and PNPase. Our findings suggest that IsrA might be directly involved in transcription or can participate in regulation of gene expression by delivering proteins associated with it to target mRNAs through its interactions with transcribing RNAP and through regions of sequence-complementarity with the target. In this eukaryotic-like model only in the context of a complex with its target, IsrA and its associated proteins become active. In this manner, in the form of sRNPs, bacterial sRNAs could regulate a number of targets with various outcomes, depending on the set of associated proteins.