Smirnov Alexandre, Wang Chuan, Drewry Lisa L, Vogel Jörg
RNA Biology Group, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany.
RNA Biology Group, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
EMBO J. 2017 Apr 13;36(8):1029-1045. doi: 10.15252/embj.201696127. Epub 2017 Mar 23.
Research into post-transcriptional control of mRNAs by small noncoding RNAs (sRNAs) in the model bacteria and 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 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 the mRNA of histone-like protein HU-α. RaiZ forms an RNA duplex with the ribosome-binding site of 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.
对模式细菌中小非编码RNA（sRNA）对mRNA转录后调控的研究主要集中在与RNA伴侣蛋白Hfq相关的sRNA上。然而，最近发现蛋白质ProQ作为一种常见的结合伴侣，可稳定一类独特的结构化sRNA，这表明这些生物体中存在额外的RNA调控子。这些新的依赖ProQ的sRNA的细胞功能和分子机制在很大程度上尚不清楚。在这里，我们报道了鼠伤寒沙门氏菌中RaiZ的作用模式，RaiZ是一种依赖ProQ的sRNA，由编码核糖体失活蛋白RaiA的mRNA的3'末端产生。我们表明，RaiZ是一种碱基配对的sRNA，可抑制组蛋白样蛋白HU-α的mRNA表达。RaiZ在ProQ的帮助下与HU-α mRNA的核糖体结合位点形成RNA双链体，以阻止30S核糖体加载和HU-α的蛋白质合成。我们将讨论ProQ和Hfq介导的调控之间的异同。
