Characterisation of the regulatory RNA RsmB from Pseudomonas aeruginosa PAO1
Characterisation of the regulatory RNA RsmB from Pseudomonas aeruginosa PAO1
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DOI：
10.1016/j.resmic.2004.07.004
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发表时间：
2005-01-01
影响因子：
2.6
通讯作者：
O'Gara, F
中科院分区：
文献类型：
--
作者：
Burrowes, E;Abbas, A;O'Gara, F
在铜绿假单胞菌中，毒力因子和次级代谢产物的分子调控受到严格控制。这种控制涉及多个信号介导的调控网络，包括 GacS-GacA 系统和群体感应。最近，转录后阻遏蛋白 RsmA 与次级代谢产物的产生有关。推测 RsmA 与一种尚未鉴定的调节性 RNA 分子协同工作，其方式类似于其他细菌中的同源物。在这里，我们鉴定了编码非翻译调节 RNA (RsmB) 的基因。位于铜绿假单胞菌 PAO 1 基因组的 rpoS/fdxA 基因间区域。铜绿假单胞菌中 rsmB 的过表达导致 N-酰基高丝氨酸内酯、绿脓素和弹性蛋白酶产量增加，而 rsmA 过表达时则显着减少。与野生型相比，rsmB 突变导致 AHL 产量减少。我们认为 RsmB 是铜绿假单胞菌中 RsmA 的同源调节 RNA。与荧光假单胞菌的情况一样，铜绿假单胞菌中的 rsmB 转录并不绝对需要全局调节因子 GacA。然而。 GacA 影响 rsmB 转录的动力学，因为在稳定期后期，与野生型相比，gacA 突变体显示 rsmB 转录水平大幅降低。 RsmA 也影响 rsmB；在 rsmA 突变体中，rsmB 转录物的稳态水平降低，这是由于 RsmA 水平的 rsmA 平衡转录减少，RsmB 可能是一种自动调节机制，以确保 RsmA 受到严格控制，正如对这种有效的全局阻遏物所预期的那样。 (C) 2004 年爱思唯尔 SAS。版权所有。
In Pseudomonas aeruginosa, the molecular regulation of virulence factors and secondary metabolites is tightly controlled. This control involves several signal-mediated regulatory networks, including the GacS-GacA system and quorum sensing. Recently, the postranscriptional repressor protein RsmA has been implicated in secondary metabolite production. RsmA is postulated to work in tandem with an as yet unidentified regulatory RNA molecule in a manner analogous to its homologues in other bacteria. Here we have identified a gene encoding an untranslated regulatory RNA (RsmB). located in the rpoS/fdxA intergenic region of the P. aeruginosa PAO 1 genome. Overexpression of rsmB in P. aeruginosa resulted in an increase in N-acyl-homoserine lactone, pyocyanin and elastase production compared with a marked decrease when rsmA was overexpressed. Mutation of rsmB resulted in a decrease in AHL production compared to wild type. We propose that RsmB is the cognate regulatory RNA of RsmA in P. aeruginosa. The global regulator GacA was not absolutely required for rsmB Transcription in P. aeruginosa, as is the case in Pseudomonas fluorescens. However. GacA influenced the kinetics of rsmB transcription in that in late stationary phase the gacA mutant showed a substantial reduction in rsmB transcript levels compared to wild type. RsmA also influenced rsmB; in an rsmA mutant, the steady state level of rsmB transcript was reduced and this was due to a decrease in the transcription of rsmA balance in the levels of RsmA and RsmB may be an autoregulatory mechanism to ensure that RsmA is tightly controlled, as might be expected for such a potent global repressor. (C) 2004 Elsevier SAS. All rights reserved.