转录调节因子σ^(38)介导铜绿假单胞菌绿脓菌素合成代谢调控  

Regulation of pyocyanin biosynthesis by transcriptional factor sigma^(38) in Pseudomonas aeruginosa PAO1

作　　者：缪静[1] 迟晓艳[1] 王艳华[1] 冯志彬[1] 薛文文[1] 黄润[1] 张颢译[1] 田铃仟 张洪倩 翟俊杰[1] 葛宜和[1] Jing Miao Xiaoyan Chi Yanhua Wang Zhibin Feng Wenwen Xue Run Huang Haoyi Zhang Lingqian Tian Hongqian Zhang Junjie Zhai Yihe Ge(School of Biological Sciences, Ludong University, Yantai 264025, Shandong Province, Chin)

机构地区：[1]鲁东大学生命科学学院,山东烟台264025

出　　处：《微生物学报》2017年第2期229-239,共11页Acta Microbiologica Sinica

基　　金：山东省自然科学基金(ZR2011CL003);山东省高等学校科技计划项目(J14LK53)~~

摘　　要：【目的】为了进一步鉴定铜绿假单胞菌转录调控因子σ^(38)对2个拷贝吩嗪合成基因簇(phz A1-G1和phz A2-G2)的具体调控方式并推定介导绿脓菌素合成代谢的可能调控机制。【方法】根据铜绿假单胞菌基因组信息,利用同源重组原理构建rpo S基因缺失突变株Δrpo S以及克隆全长rpo S基因作互补分析;再以单一吩嗪基因簇缺失突变株Δphz1和Δphz2为出发菌株,分别构建rpo S缺失突变株Δrpo Sphz1和rpo S插入突变株Δrpo Sphz2,测定并比较野生株及相关突变株的绿脓菌素合成量,初步推定σ^(38)因子对2个不同吩嗪基因簇表达的调控方式。【结果】在GA培养基中,突变株Δrpo S的绿脓菌素合成量比野生株显著增加;互补分析证实,σ^(38)可使突变株Δrpo S的绿脓菌素降低并接近野生株PAO1水平;与对照株Δphz1相比,突变株Δrpo Sphz1的绿脓菌素合成量因σ^(38)因子缺失而显著减少;而与对照株Δphz2相比,突变株Δrpo Sphz2的绿脓菌素合成量因σ^(38)因子缺失显著增加。【结论】转录调控因子σ^(38)对铜绿假单胞菌绿脓菌素的合成代谢的确具一定的负调控作用;结合已报道的研究结果,初步推定:σ^(38)因子通过负调控吩嗪基因簇phz1,正调控吩嗪基因簇phz2的表达实现对绿脓菌素合成代谢的调控。Pyocyanin, an important virulence factor, is synthesized and secreted by Pseudomonas aeruginosa PAOland plays a critical role in pathogen-host interaction during infection. Sigma^38 （σ^38, σ^S） is a central regulator for many virulence production in pathogens. [Objective] Our aim is to identify expression and regulation of two phenazine-producing operons mediated by the sigma^38 factor in Pseudomonas aeruginosa PAO1. [Methods] We first cloned the flanking fragments of rpoS from the chromosomal DNA of P. aeruginosa PAO 1 and constructed the deletion mutant ArpoS with the insertion of gentamycin resistance cassette （aacC1）. Complementation of rpoS was then carried out after construction and introduction of pME10S （containing the whole rpoS region）. Finally, we created the mutant ArpoSphzl and △rpoSphz2, and measured pyocyanin production by these mutants in GA medium, using the parental strain Aphzl and △phz2 as controls. [Results] In GA medium, pyocyanin production by mutant △rpoS increased dramatically in comparison with the wild-type strain PAO1. Production of pyocyanin, however, was decreased to the level of the wild-type strain with complementation of the derivative ArpoS harboring pME10S. Mutant △rpoSphz2 produced much more produced much less pyocyanin than mutant Aphzl. and negatively regulating the phzl, sigma38 factor aeruginosa PAO 1. pyocyanin than mutant △phz2. Mutant ArpoSphzl, however, [Conclusion] By positively regulating the expression of phz2 exerts negative modulation on pyocyanin biosynthesis in PAOI.

关 键 词：铜绿假单胞菌 σ^38因子 phzl phz2 绿脓菌素 基因调控 

分 类 号：Q78[生物学—分子生物学]