RNases are key regulatory components in prokaryotes, responsible for the degradation and maturation of specific RNA molecules at precise times. Specifically, RNases allow cells to cope with changes in their environment through rapid alteration of gene expression. To date, few RNases have been characterized in the mammalian pathogen Brucella abortus. In the present work, we sought to investigate several RNases in B. abortus and determine what role, if any, they have in pathogenesis. Of the 4 RNases reported in this study, the highly conserved endoribonuclease, RNase E, was found to play an integral role in the virulence of B. abortus. Although rne, which encodes RNase E, is essential in B. abortus, we were able to generate a strain encoding a defective version of RNase E lacking the C-terminal portion of the protein, and this strain (rne-tnc) was attenuated in a mouse model of Brucella infection. RNA-sequencing analysis revealed massive RNA dysregulation in B. abortus rne-tnc, with 122 upregulated and 161 downregulated transcripts compared to the parental strain. Interestingly, several mRNAs related to metal homeostasis were significantly decreased in the rne-tnc strain. We also identified a small regulatory RNA (sRNA), called Bsr4, that exhibited significantly elevated levels in rne-tnc, demonstrating an important role for RNase E in sRNA-mediated regulatory pathways in Brucella. Overall, these data highlight the importance of RNase E in B. abortus, including the role of RNase E in properly controlling mRNA levels and contributing to virulence in an animal model of infection.

中文翻译：

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核糖核酸内切酶RNase E协调mRNA和小的调节性RNA的表达，对于布鲁氏流产的毒力至关重要。

核糖核酸酶是原核生物中的关键调控成分，负责特定RNA分子在精确时间的降解和成熟。具体而言，RNase允许细胞通过快速改变基因表达来应对环境变化。迄今为止，在哺乳动物病原体流产布鲁氏菌中几乎没有RNA酶的特征。在目前的工作中，我们试图调查流产双歧杆菌中的几种RNase，并确定它们在发病机理中的作用（如果有）。在这项研究中报道的4种RNase中，高度保守的核糖核酸内切酶RNase E被发现在流产双歧杆菌的毒力中起着不可或缺的作用。虽然RNE，编码RNA酶E，是人体必需的B.流产，我们能够产生编码的RNA酶E的缺陷版本缺乏该蛋白的C-末端部分的菌株，该菌株（RNE -tnc）在小鼠模型中减弱布鲁氏菌感染。RNA测序分析显示大规模RNA失调中B.流产 RNE相比亲本菌株-tnc，与122个上调和下调161转录。有趣的是，与金属稳态几个的mRNA在中显著降低RNE -tnc应变。我们还确定了小RNA调控（斯尔纳），称为Bsr4，在表现出显著水平升高RNE -tnc，表明RNA酶的E重要作用斯尔纳介导的调控途径在布鲁切拉（Brucella）。总体而言，这些数据突出了流产双歧杆菌中RNase E的重要性，包括RNase E在适当控制mRNA水平和在感染动物模型中提高毒力方面的作用。