The RNA-binding protein Hfq of Listeria monocytogenes:: Role in stress tolerance and virulence
The RNA-binding protein Hfq of Listeria monocytogenes:: Role in stress tolerance and virulence
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DOI：
10.1128/jb.186.11.3355-3362.2004
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发表时间：
2004-06-01
影响因子：
3.2
通讯作者：
Kallipolitis, BH
中科院分区：
文献类型：
--
作者：
Christiansen, JK;Larsen, MH;Kallipolitis, BH
在革兰氏阴性菌中，RNA结合蛋白Hfq已成为多种生理过程中的重要调节因子，包括胁迫抗性和毒力。在大肠杆菌中，Hfq调节mRNA的稳定性或翻译，并与许多小的调控RNA相互作用。在这里，我们研究了Hfq在革兰氏阳性食源性人类病原体单核细胞增多性李斯特菌的应激耐受性和毒力中的作用。我们提出的证据表明，Hfq参与的能力，L。单核细胞增多症耐受渗透压和乙醇应激，并有助于在氨基酸限制条件下的长期生存。然而，Hfq不是抗酸和氧化应激所必需的。hfq的转录在各种胁迫条件下被诱导，包括渗透胁迫和乙醇胁迫以及进入稳定生长期，从而支持Hfq对L.单核细胞增多症在恶劣的环境中。hfq的胁迫诱导转录依赖于选择性sigma因子sigma（B），该因子控制L.单核细胞增多症。感染研究表明，Hfq有助于小鼠的发病机制，但在培养的细胞系的感染中不起作用。这项研究首次提供了Hfq在革兰氏阳性病原菌的胁迫耐受性和毒力中的作用的信息。
In gram-negative bacteria, the RNA-binding protein Hfq has emerged as an important regulatory factor in a variety of physiological processes, including stress resistance and virulence. In Escherichia coli, Hfq modulates the stability or the translation of mRNAs and interacts with numerous small regulatory RNAs. Here, we studied the role of Hfq in the stress tolerance and virulence of the gram-positive food-borne human pathogen Listeria monocytogenes. We present evidence that Hfq is involved in the ability of L. monocytogenes to tolerate osmotic and ethanol stress and contributes to long-term survival under amino acid-limiting conditions. However, Hfq is not required for resistance to acid and oxidative stress. Transcription of hfq is induced under various stress conditions, including osmotic and ethanol stress and at the entry into the stationary growth phase, thus supporting the view that Hfq is important for the growth and survival of L. monocytogenes in harsh environments. The stress-inducible transcription of hfq depends on the alternative sigma factor sigma(B), which controls the expression of numerous stress- and virulence-associated genes in L. monocytogenes. Infection studies showed that Hfq contributes to pathogenesis in mice, yet plays no role in the infection of cultured cell lines. This study provides, for the first time, information on the role of Hfq in the stress tolerance and virulence of a gram-positive pathogen.