Small RNAs encoded within genetic islands of Salmonella typhimurium show host-induced expression and role in virulence.
Small RNAs encoded within genetic islands of Salmonella typhimurium show host-induced expression and role in virulence.
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DOI：
10.1093/nar/gkn050
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发表时间：
2008-04
影响因子：
14.9
通讯作者：
Altuvia S
中科院分区：
文献类型：
--
作者：
Padalon-Brauch G;Hershberg R;Elgrably-Weiss M;Baruch K;Rosenshine I;Margalit H;Altuvia S
肠道细菌致病菌株的出现及其对独特生态位的适应与获得被称为“遗传岛”的外来DNA片段有关。我们探索了这些岛屿以寻找编码基因的小RNA(SRNA)的出现。以前对肠道细菌sRNA的系统筛选主要是使用实验室菌株Escherichia coliK12进行的，导致发现了∼80新的sRNA基因。这些搜索是基于肠道细菌密切相关成员的保守性，因此排除了致病菌株特有的sRNA。在这里，我们描述了19个新的独特的sRNA基因的鉴定和特征，这些基因编码在强毒力鼠伤寒沙门氏菌的‘基因岛’中。我们发现，许多岛编码基因的表达与胁迫条件和稳定期有关。当沙门氏菌停留在巨噬细胞内时，其中几个sRNA基因被诱导。进一步研究发现，一种名为IsrJ的SRNA可以影响毒力相关效应蛋白向非吞噬细胞的转位效率。此外，我们还报道，与大多数作为反式调节因子的大肠杆菌sRNA不同，许多岛编码的sRNA影响顺式编码基因的表达。我们的研究表明，编码sRNA基因的岛在调节细菌对环境变化和应激条件的适应从而控制毒力的网络中发挥着重要作用。
The emergence of pathogenic strains of enteric bacteria and their adaptation to unique niches are associated with the acquisition of foreign DNA segments termed ‘genetic islands’. We explored these islands for the occurrence of small RNA (sRNA) encoding genes. Previous systematic screens for enteric bacteria sRNAs were mainly carried out using the laboratory strain Escherichia coli K12, leading to the discovery of ∼80 new sRNA genes. These searches were based on conservation within closely related members of enteric bacteria and thus, sRNAs, unique to pathogenic strains were excluded. Here we describe the identification and characterization of 19 novel unique sRNA genes encoded within the ‘genetic islands’ of the virulent strain Salmonella typhimurium. We show that the expression of many of the island-encoded genes is associated with stress conditions and stationary phase. Several of these sRNA genes are induced when Salmonella resides within macrophages. One sRNA, IsrJ, was further examined and found to affect the translocation efficiency of virulence-associated effector proteins into nonphagocytic cells. In addition, we report that unlike the majority of the E. coli sRNAs that are trans regulators, many of the island-encoded sRNAs affect the expression of cis-encoded genes. Our study suggests that the island encoded sRNA genes play an important role within the network that regulates bacterial adaptation to environmental changes and stress conditions and thus controls virulence.
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影响因子：
3.2
作者：
Charpentier, X;Oswald, E
通讯作者：
Oswald, E
影响因子：
3.1
作者：
Fortune, DR;Suyemoto, M;Altier, C
通讯作者：
Altier, C
影响因子：
3.2
作者：
Christiansen, JK;Larsen, MH;Kallipolitis, BH
通讯作者：
Kallipolitis, BH
影响因子：
2.6
作者：
Burrowes, E;Abbas, A;O'Gara, F
通讯作者：
O'Gara, F
影响因子：
15.9
作者：
Groisman, EA;Ochman, H
通讯作者：
Ochman, H