Identification of genes involved in low aminoglycoside-induced SOS response in Vibrio cholerae: a role for transcription stalling and Mfd helicase.
Identification of genes involved in low aminoglycoside-induced SOS response in Vibrio cholerae: a role for transcription stalling and Mfd helicase.
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DOI：
10.1093/nar/gkt1259
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发表时间：
2014-02
影响因子：
14.9
通讯作者：
Mazel D
中科院分区：
文献类型：
--
作者：
Baharoglu Z;Babosan A;Mazel D
抗生素的亚抑制浓度（sub-MIC）在耐药性的选择和发展中起着非常重要的作用。与大肠杆菌不同，霍乱弧菌在亚mic氨基糖苷的存在下诱导其SOS反应。观察到氧化鸟嘌呤残基的作用，但这种诱导的机制尚不清楚。为了选择不诱导低氨基糖苷介导的SOS诱导的霍乱弧菌突变体，我们开发了一种使SOS诱导致死的遗传筛选。我们使用两种策略，通过转位失活和基因过表达来确定参与该途径的基因。有趣的是，我们获得了因已知的破坏RNA聚合酶复合物稳定的蛋白质表达而失活的突变体。相应突变体的重建证实了它们在低氨基糖苷浓度诱导SOS的特异性参与。我们提出在氨基糖苷处理下形成的DNA损伤通过形成单链DNA中间体来修复，从而诱导SOS。去除RNA聚合酶的功能失活导致这些病变长时间停滞，这阻碍了SOS的诱导和修复，并降低了抗生素应激下的生存能力。氨基糖苷亚mic的减少说明了这些机制的重要性。我们的研究结果指出了在SOS诱导中DNA损伤处的转录阻断的核心作用，迄今为止被低估了。
Sub-inhibitory concentrations (sub-MIC) of antibiotics play a very important role in selection and development of resistances. Unlike Escherichia coli, Vibrio cholerae induces its SOS response in presence of sub-MIC aminoglycosides. A role for oxidized guanine residues was observed, but the mechanisms of this induction remained unclear. To select for V. cholerae mutants that do not induce low aminoglycoside-mediated SOS induction, we developed a genetic screen that renders induction of SOS lethal. We identified genes involved in this pathway using two strategies, inactivation by transposition and gene overexpression. Interestingly, we obtained mutants inactivated for the expression of proteins known to destabilize the RNA polymerase complex. Reconstruction of the corresponding mutants confirmed their specific involvement in induction of SOS by low aminoglycoside concentrations. We propose that DNA lesions formed on aminoglycoside treatment are repaired through the formation of single-stranded DNA intermediates, inducing SOS. Inactivation of functions that dislodge RNA polymerase leads to prolonged stalling on these lesions, which hampers SOS induction and repair and reduces viability under antibiotic stress. The importance of these mechanisms is illustrated by a reduction of aminoglycoside sub-MIC. Our results point to a central role for transcription blocking at DNA lesions in SOS induction, so far underestimated.
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影响因子：
3.6
作者：
Baharoglu Z;Lestini R;Duigou S;Michel B
通讯作者：
Michel B
影响因子：
4.5
作者：
Baharoglu Z;Bikard D;Mazel D
通讯作者：
Mazel D
影响因子：
4.5
作者：
Baharoglu Z;Bradley AS;Le Masson M;Tsaneva I;Michel B
通讯作者：
Michel B
影响因子：
4.5
作者：
De Septenville, Anne L.;Duigou, Stephane;Michel, Benedicte
通讯作者：
Michel, Benedicte
影响因子：
3.2
作者：
Baharoglu, Zeynep;Krin, Evelyne;Mazel, Didier
通讯作者：
Mazel, Didier