嗜水气单胞菌zntR调控的生理功能及其机制研究

Physiological function and mechanism of zntR gene regulation in Aeromonas hydrophila

摘要:

[目的] ZntR是一种金属调控蛋白，可催化锌外排基因的转录激活，防止细胞内二价Zn离子过量，但其对细菌生理功能的影响目前尚不清楚。[方法] 本研究构建了嗜水气单胞菌ATCC7966（Aeromonas hydrophila，A.h）的zntR缺失株及补救株，对菌株的生物被膜形成能力、溶血活性、运动能力和响应金属离子胁迫等生理表型进行评估。[结果] 敲除zntR基因的菌株对锌和铬离子胁迫敏感、对钴离子胁迫耐受，并且生物被膜形成能力下降、运动能力增强，这些表型在其补救菌株中均能得到恢复。进一步利用DIA定量蛋白质组学技术比较野生株和zntR缺失株的蛋白表达差异，发现ZntR还可能参与双组分系统、细菌的趋化性等代谢通路的调控。[结论] 该研究结果可为今后深入探讨zntR转录因子参与细菌生理功能的调控机制提供理论依据。

关键词:嗜水气单胞菌;转录调控因子;同源重组

Abstract:

[Objective] ZntR is a metal regulatory protein, which can catalyze the transcriptional activation of zinc efflux genes, thus controlling the intracellular Zn(II) from toxic. However, the effect of zntR on bacterial biological function remains unclear.[Methods] In this study, we constructed Aeromonas hydrophila (A.h) ∆zntR deletion strain and ∆zntR::zntR rescued strain to evaluate the biofilm formation ability, hemolytic activity, motility ability, the characters of responding to metal ion stress and other physiological phenotypes.[Results] The results showed that zntR deletion strain was sensitive to zinc and chromium stress and tolerant to cobalt ion stress, meanwhile, the biofilm formation ability was decreased and the movement ability was enhanced. These phenotypes could be recovered in the rescue strains. Furthermore, the differential protein expression between wild-type strain and zntR deletion strain was compared by DIA based quantitative proteomics. Results showed that zntR may also be involved in the regulation of two-component system, bacterial chemotaxis and other metabolic pathways.[Conclusion] The above research can provide theoretical basis for further study on the regulation mechanism of ZntR transcription factors in bacterial physiological function.

Key words:Aeromonas hydrophila;transcriptional regulator;homologous recombination