Pivotal Roles for Ribonucleases in Streptococcus pneumoniae Pathogenesis.
Pivotal Roles for Ribonucleases in Streptococcus pneumoniae Pathogenesis.
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DOI：
10.1128/mbio.02385-21
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发表时间：
2021-10-26
期刊：
影响因子：
6.4
通讯作者：
De Lay NR
中科院分区：
文献类型：
--
作者：
Sinha D;Frick JP;Clemons K;Winkler ME;De Lay NR
核糖核酸酶通过处理和/或降解RNA，在调节许多细菌病原体的基因表达方面发挥着不可或缺的功能。尽管核糖核酸酶在调节细菌毒力因子中起着关键作用，但在人类主要呼吸道病原体肺炎链球菌中，核糖核酸酶的功能尚未被研究。在这里，我们试图确定两种保守的RNase，即内切核糖核酸酶Y和外切核糖核酸酶多核苷酸磷酸化酶(PNPase)，对肺炎链球菌2型D39株的生理和毒力的影响。我们报告说，RNaseY和PNPase在肺炎球菌的发病机制中是必不可少的，因为这两个缺失突变在侵袭性肺炎的小鼠模型中都显示出强烈的毒力减弱。全基因组转录分析表明，与野生型相比，ΔRNY突变体中近200mRNAs的丰度显著增加，而包括CIAR控制的非编码RNA(CCN)在内的几个肺炎球菌小调节RNA(SRNA)的丰度发生了变化。此外，缺乏核糖核酸酶Y导致了多效性表型，包括肺炎球菌细胞形态和体外生长缺陷。相比之下，TIGR4PNP突变体在体外没有显示出生长缺陷，但差异表达了总共40个转录本，包括色氨酸生物合成操纵子基因和许多5‘顺式作用调节RNA，其中大部分先前被证明影响使用4型Δ菌株的小鼠肺炎球菌疾病的进展。综上所述，我们的数据表明，RNaseY对肺炎球菌的生理学产生了全球性的影响，而PNPase可能通过SRNA调控来调节毒力表型。
RNases perform indispensable functions in regulating gene expression in many bacterial pathogens by processing and/or degrading RNAs. Despite the pivotal role of RNases in regulating bacterial virulence factors, the functions of RNases have not yet been studied in the major human respiratory pathogen Streptococcus pneumoniae (pneumococcus). Here, we sought to determine the impact of two conserved RNases, the endoribonuclease RNase Y and exoribonuclease polynucleotide phosphorylase (PNPase), on the physiology and virulence of S. pneumoniae serotype 2 strain D39. We report that RNase Y and PNPase are essential for pneumococcal pathogenesis, as both deletion mutants showed strong attenuation of virulence in murine models of invasive pneumonia. Genome-wide transcriptomic analysis revealed that the abundances of nearly 200 mRNA transcripts were significantly increased, whereas those of several pneumococcal small regulatory RNAs (sRNAs), including the Ccn (CiaR-controlled noncoding RNA) sRNAs, were altered in the Δrny mutant relative to the wild-type strain. Additionally, lack of RNase Y resulted in pleiotropic phenotypes that included defects in pneumococcal cell morphology and growth in vitro. In contrast, Δpnp mutants showed no growth defect in vitro but differentially expressed a total of 40 transcripts, including the tryptophan biosynthesis operon genes and numerous 5′ cis-acting regulatory RNAs, a majority of which were previously shown to impact pneumococcal disease progression in mice using the serotype 4 strain TIGR4. Together, our data suggest that RNase Y exerts a global impact on pneumococcal physiology, while PNPase mediates virulence phenotypes, likely through sRNA regulation.