Is PhoR-PhoP partner fidelity strict? PhoR is required for the activation of the pho regulon in Streptomyces coelicolor
Is PhoR-PhoP partner fidelity strict? PhoR is required for the activation of the pho regulon in Streptomyces coelicolor
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DOI：
10.1007/s00438-012-0698-4
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发表时间：
2012-07-01
影响因子：
3.1
通讯作者：
Martin, Juan F.
中科院分区：
文献类型：
--
作者：
Fernandez-Martinez, Lorena T.;Santos-Beneit, Fernando;Martin, Juan F.
双组分调节系统在细胞代谢适应不断变化的营养和环境条件中起着关键作用。双组分系统的两个同源蛋白质之间的保真度是重要的，因为它决定了特定的反应调节剂是否整合了由不同传感器激酶传递的信号。天蓝色链霉菌的磷酸盐调节主要由PhoR-PhoP双组分系统介导。以前的研究阐明了控制磷酸盐调节的机制，以及在这种生物体中由反应调节因子PhoP（pho调节子）直接调节的基因。然而，组氨酸激酶PhoR在天蓝色链霉菌中的作用至今尚未阐明。在这项工作中，我们报告了一个非极性的δ phoR缺失突变体在S。coelicolor保持其天然启动子。诱导的phoRP操纵子依赖于磷酸化的phoP，但三角洲phoR突变体表达phoP在基础水平。RT-PCR和报告荧光素酶分析表明，PhoR在这种生物体中的pho调节子的激活中起着关键作用。我们的研究结果指向一个严格的同源合作伙伴的特异性方面的磷酸化PhoP的PhoR，从而证实了该系统的两个组件之间的紧密相互作用。
Two-component regulatory systems play a key role in the cell metabolism adaptation to changing nutritional and environmental conditions. The fidelity between the two cognate proteins of a two-component system is important since it determines whether a specific response regulator integrates the signals transmitted by different sensor kinases. Phosphate regulation in Streptomyces coelicolor is mostly mediated by the PhoR-PhoP two-component system. Previous studies elucidated the mechanisms that control phosphate regulation as well as the genes directly regulated by the response regulator PhoP (pho regulon) in this organism. However, the role of the histidine kinase PhoR in Streptomyces coelicolor had not been unveiled so far. In this work, we report the characterization of a non-polar Delta phoR deletion mutant in S. coelicolor that keeps its native promoter. Induction of the phoRP operon was dependent upon phosphorylation of PhoP, but the Delta phoR mutant expressed phoP at a basal level. RT-PCR and reporter luciferase assays demonstrated that PhoR plays a key role in the activation of the pho regulon in this organism. Our results point towards a strict cognate partner specificity in terms of the phosphorylation of PhoP by PhoR thus corroborating the tight interaction between the two-components of this system.