The ColR-ColS two-component signal transduction system is involved in regulation of Tn4652 transposition in Pseudomonas putida under starvation conditions
The ColR-ColS two-component signal transduction system is involved in regulation of Tn4652 transposition in Pseudomonas putida under starvation conditions
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DOI：
10.1111/j.1365-2958.2004.04311.x
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发表时间：
2004-11-01
影响因子：
3.6
通讯作者：
Kivisaar, M
中科院分区：
文献类型：
--
作者：
Horak, R;Ilves, H;Kivisaar, M
细菌使用双组分信号转导途径来感知细胞外和细胞内环境，并根据变化的条件来协调细胞事件。适应可以是生理的，也可以是遗传的。在这里，我们提出的证据表明，基因组重组过程，如转座，可以控制由双组分信号转导系统所感知的某些环境线索。我们表明，转座依赖积累的苯酚利用突变体严重减少恶臭假单胞菌缺陷的双组分系统colRS。Tn4652的易位在colR和colS缺陷菌株中均降低，表明从组氨酸激酶ColS到响应调节剂ColR的信号转导对于在苯酚饥饿的细菌中激活Tn4652是必要的。然而，ColR在ColS缺陷型菌株中的过表达恢复了Tn4652转座，表明ColS信号的缺失可以通过ColR量的升高来补偿。纯化的ColR和ColS蛋白的体外分析证明它们构成功能性磷酸化中继。定点突变表明，一个保守的H221可以在ColS中的磷酸化接受残基和ColR的天冬氨酸残基D8和D51是必要的从ColS到ColR的磷酸转移。据我们所知，Tn4652是第一个由双组分系统调控的细菌转座子。这一发现表明，易位活动可以对宿主感知和处理的信号做出反应。
Bacteria use two-component signal transduction pathways to sense both extracellular and intracellular environment and to coordinate cellular events according to changing conditions. Adaptation can be either physiological or genetical. Here, we present evidence that a genome reorganization process such as transposition can be controlled by certain environmental cues sensed by a two-component signal transduction system. We demonstrate that transposition-dependent accumulation of phenol-utilizing mutants is severely decreased in Pseudomonas putida defective in a two-component system colRS. Translocation of Tn4652 is decreased both in colR- and colS-defective strains, indicating that signal transduction from a histidine kinase ColS to a response regulator ColR is necessary for the activation of Tn4652 in bacteria starving on phenol. However, overexpression of ColR in a colS-defective strain restores Tn4652 transposition, suggesting that absence of the signal from ColS can be compensated by an elevated amount of ColR. In vitro analysis of purified ColR and ColS proteins evidenced that they constitute a functional phosphorelay. Site-directed mutagenesis revealed that a conserved H221 can be the phosphoryl-accepting residue in ColS and that aspartate residues D8 and D51 of ColR are necessary for the phosphotransfer from ColS to ColR. To our knowledge, Tn4652 is the first bacterial transposon regulated by a two-component system. This finding indicates that transpositional activity can respond to signals sensed and processed by the host.