RNA-mediated reciprocal regulation between two bacterial operons is RNase III dependent.
RNA-mediated reciprocal regulation between two bacterial operons is RNase III dependent.
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作者：
Johnson CM;Haemig HH;Chatterjee A;Wei-Shou H;Weaver KE;Dunny GM
在细菌中，RNA通过几种机制调节基因表达和功能。RNA可以与靶RNA中的互补序列配对以影响靶的转录、翻译或降解。粪肠球菌的信息素应答质粒pCF 10的接合控制是一个充分表征的系统，其作为通过细胞间信号传导调节细菌中基因表达的模型。其产物介导缀合的prgQ操纵子受prgX操纵子的两种产物（抗Q（一种小RNA）和PrgX（prgQ启动子的转录阻遏物））负调控。在这里，我们表明，Qs，从5′端的prgQ操纵子的RNA，抑制PrgX的表达，通过靶向prgX mRNA切割的RNase III。我们的研究结果表明，prgQ和prgX操纵子各自使用RNA通过不同的机制负调控相对操纵子的基因表达。使用RNA的两个操纵子之间的这种相互调节以前没有被证明。此外，这些结果表明，Qs是一种非常通用的RNA，在接合调节中具有三种不同的功能。了解RNA的潜在多功能性及其在基因调控网络中的各种作用将使我们更好地了解细胞如何调控复杂的行为。重要性细菌利用RNA通过多种机制调节基因表达。粪肠球菌接合质粒pCF 10的prgQ和prgX操纵子已被证明通过多种机制相互负调控。这些机制之一涉及Anti-Q，一种来自prgX操纵子的小RNA，其阻止来自prgQ操纵子的基因表达。在这项工作中，我们发现，Qs，从prgQ操纵子的RNA，负调控基因表达的prgX操纵子。这些发现具有若干含义。(i)Anti-Q和Qs RNA通过不同的机制起作用，突出了细菌可以使用RNA调节基因表达的各种方式。(ii)小RNA介导的操纵子之间的相互调节以前没有描述过，加深了我们对细菌如何调节复杂行为的理解。(iii)已经描述了Qs的其他作用，证明了这种RNA的多功能性。细菌利用RNA通过多种机制调节基因表达。粪肠球菌接合质粒pCF 10的prgQ和prgX操纵子已被证明通过多种机制相互负调控。这些机制之一涉及Anti-Q，一种来自prgX操纵子的小RNA，其阻止来自prgQ操纵子的基因表达。在这项工作中，我们发现，Qs，从prgQ操纵子的RNA，负调控基因表达的prgX操纵子。这些发现具有若干含义。(i)Anti-Q和Qs RNA通过不同的机制起作用，突出了细菌可以使用RNA调节基因表达的各种方式。(ii)小RNA介导的操纵子之间的相互调节以前没有描述过，加深了我们对细菌如何调节复杂行为的理解。(iii)已经描述了Qs的其他作用，证明了这种RNA的多功能性。
In bacteria, RNAs regulate gene expression and function via several mechanisms. An RNA may pair with complementary sequences in a target RNA to impact transcription, translation, or degradation of the target. Control of conjugation of pCF10, a pheromone response plasmid of Enterococcus faecalis, is a well-characterized system that serves as a model for the regulation of gene expression in bacteria by intercellular signaling. The prgQ operon, whose products mediate conjugation, is negatively regulated by two products of the prgX operon, Anti-Q, a small RNA, and PrgX, the transcriptional repressor of the prgQ promoter. Here we show that Qs, an RNA from the 5′ end of the prgQ operon, represses expression of PrgX by targeting prgX mRNA for cleavage by RNase III. Our results demonstrate that the prgQ and prgX operons each use RNAs to negatively regulate gene expression from the opposing operon by different mechanisms. Such reciprocal regulation between two operons using RNAs has not been previously demonstrated. Furthermore, these results show that Qs is an unusually versatile RNA, serving three separate functions in the regulation of conjugation. Understanding the potential versatility of RNAs and their various roles in gene regulatory networks will allow us to better understand how cells regulate complex behavior. Importance Bacteria use RNA to regulate gene expression by a variety of mechanisms. The prgQ and prgX operons of pCF10, a conjugative plasmid of Enterococcus faecalis, have been shown to negatively regulate one another by a variety of mechanisms. One of these mechanisms involves Anti-Q, a small RNA from the prgX operon that prevents gene expression from the prgQ operon. In this work, we find that Qs, an RNA from the prgQ operon, negatively regulates gene expression from the prgX operon. These findings have a number of implications. (i) The Anti-Q and Qs RNAs act by different mechanisms, highlighting the variety of ways in which bacteria can regulate gene expression using RNAs. (ii) Reciprocal regulation between operons mediated by small RNAs has not been previously described, deepening our understanding of how bacteria regulate complex behavior. (iii) Additional roles for Qs have been described, demonstrating the versatility of this RNA. Bacteria use RNA to regulate gene expression by a variety of mechanisms. The prgQ and prgX operons of pCF10, a conjugative plasmid of Enterococcus faecalis, have been shown to negatively regulate one another by a variety of mechanisms. One of these mechanisms involves Anti-Q, a small RNA from the prgX operon that prevents gene expression from the prgQ operon. In this work, we find that Qs, an RNA from the prgQ operon, negatively regulates gene expression from the prgX operon. These findings have a number of implications. (i) The Anti-Q and Qs RNAs act by different mechanisms, highlighting the variety of ways in which bacteria can regulate gene expression using RNAs. (ii) Reciprocal regulation between operons mediated by small RNAs has not been previously described, deepening our understanding of how bacteria regulate complex behavior. (iii) Additional roles for Qs have been described, demonstrating the versatility of this RNA.