The stress-related, rhizobial small RNA RcsR1 destabilizes the autoinducer synthase encoding mRNA sinI in Sinorhizobium meliloti.
The stress-related, rhizobial small RNA RcsR1 destabilizes the autoinducer synthase encoding mRNA sinI in Sinorhizobium meliloti.
复制标题
DOI：
10.1080/15476286.2015.1110673
复制
发表时间：
2016-05-03
期刊：
影响因子：
4.1
通讯作者：
Evguenieva-Hackenberg E
中科院分区：
文献类型：
--
作者：
Baumgardt K;Šmídová K;Rahn H;Lochnit G;Robledo M;Evguenieva-Hackenberg E
群体感应是一种依赖于自诱导分子的细菌密度依赖性通讯系统。在分析固氮植物共生体苜蓿中华根瘤菌群体感应的转录后调控过程中，我们预测并验证了编码自诱导物合成酶的sinI mRNA的5 '-UTR与一个小RNA（sRNA）之间的直接相互作用，我们将其命名为RcsR 1。在体外，RcsR 1阻止RNA酶E在sinI的5 '-UTR中的切割，并损害sinI的翻译。与RcsR 1与sinI结合后的低核糖体占有率和转录不稳定性一致，S.结果表明，苜蓿草毒可降低sinI mRNA的表达水平，缩短sinI mRNA的半衰期，降低sinI mRNA的自诱导物含量。虽然RcsR 1可以通过sinI影响群体感应，但其水平在不同细胞密度下没有变化，但在盐胁迫下下降，在低温下增加。我们发现，RcsR 1和它的压力相关的表达模式，但不与sinI同源物的相互作用，是保守的中华根瘤菌，根瘤菌和土壤杆菌。因此，在S.苜蓿和根癌农杆菌在高盐下抑制生长。我们确定了RcsR 1的保守目标，并表明，最保守的相互作用和盐胁迫下的生长的影响是由RcsR 1的第一个茎环介导的，而其中心部分是负责物种特异性的相互作用与sinI。我们的结论是，RcsR 1是一个古老的，压力相关的核糖核酸调节子在根瘤菌，并提出它连接压力反应的群体感应在S。苜蓿草。
Quorum sensing is a cell density-dependent communication system of bacteria relying on autoinducer molecules. During the analysis of the post-transcriptional regulation of quorum sensing in the nitrogen fixing plant symbiont Sinorhizobium meliloti, we predicted and verified a direct interaction between the 5'-UTR of sinI mRNA encoding the autoinducer synthase and a small RNA (sRNA), which we named RcsR1. In vitro, RcsR1 prevented cleavage in the 5'-UTR of sinI by RNase E and impaired sinI translation. In line with low ribosomal occupancy and transcript destabilization upon binding of RcsR1 to sinI, overproduction of RcsR1 in S. meliloti resulted in lower level and shorter half-life of sinI mRNA, and in decreased autoinducer amount. Although RcsR1 can influence quorum sensing via sinI, its level did not vary at different cell densities, but decreased under salt stress and increased at low temperature. We found that RcsR1 and its stress-related expression pattern, but not the interaction with sinI homologs, are conserved in Sinorhizobium, Rhizobium and Agrobacterium. Consistently, overproduction of RcsR1 in S. meliloti and Agrobacterium tumefaciens inhibited growth at high salinity. We identified conserved targets of RcsR1 and showed that most conserved interactions and the effect on growth under salt stress are mediated by the first stem-loop of RcsR1, while its central part is responsible for the species-specific interaction with sinI. We conclude that RcsR1 is an ancient, stress-related riboregulator in rhizobia and propose that it links stress responses to quorum sensing in S. meliloti.