Molecular mechanism of mRNA repression in trans by a ProQ-dependent small RNA.
Molecular mechanism of mRNA repression in trans by a ProQ-dependent small RNA.
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DOI：
10.15252/embj.201696127
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发表时间：
2017-04-13
期刊：
影响因子：
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通讯作者：
Vogel J
中科院分区：
文献类型：
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作者：
Smirnov A;Wang C;Drewry LL;Vogel J
在模式细菌大肠杆菌和肠道沙门氏菌中，通过小的非编码RNA（sRNA）对mRNA的转录后控制的研究主要集中在与RNA伴侣Hfq相关的sRNA上。然而，最近发现的蛋白质ProQ作为一个共同的结合伴侣，稳定了一个独特的大类结构的sRNA表明，额外的RNA调节子存在于这些生物体。这些新的ProQ依赖性sRNA的细胞功能和分子机制在很大程度上是未知的。在这里，我们报告了鼠伤寒沙门氏菌中RaiZ的作用方式，RaiZ是一种ProQ依赖性sRNA，由编码核糖体失活蛋白赖亚的mRNA的3′端制成。我们发现RaiZ是一种碱基配对的sRNA，可以反式抑制组蛋白样蛋白HU-α的mRNA。在ProQ的促进下，RaiZ与hupA mRNA的核糖体结合位点形成RNA双链体，以阻止HU-α的30 S核糖体加载和蛋白质合成。将讨论ProQ和Hfq介导的调节之间的相似性和差异。
Research into post‐transcriptional control of mRNAs by small noncoding RNAs (sRNAs) in the model bacteria Escherichia coli and Salmonella enterica has mainly focused on sRNAs that associate with the RNA chaperone Hfq. However, the recent discovery of the protein ProQ as a common binding partner that stabilizes a distinct large class of structured sRNAs suggests that additional RNA regulons exist in these organisms. The cellular functions and molecular mechanisms of these new ProQ‐dependent sRNAs are largely unknown. Here, we report in Salmonella Typhimurium the mode‐of‐action of RaiZ, a ProQ‐dependent sRNA that is made from the 3′ end of the mRNA encoding ribosome‐inactivating protein RaiA. We show that RaiZ is a base‐pairing sRNA that represses in trans the mRNA of histone‐like protein HU‐α. RaiZ forms an RNA duplex with the ribosome‐binding site of hupA mRNA, facilitated by ProQ, to prevent 30S ribosome loading and protein synthesis of HU‐α. Similarities and differences between ProQ‐ and Hfq‐mediated regulation will be discussed.