军事医学2017，Vol.41Issue(5)：373-376,4.DOI:10.7644/j.issn.1674-9960.2017.05.010
不同培养条件下鼠疫菌PhoP/PhoQ的自调控模式研究
Autoregulation of PhoP/PhoQ in Yersinia pestis under different conditions
摘要
Abstract
Objective To investigate the transcriptional autoregulation of PhoP/PhoQ under different growth conditions in Yersinia pestis.Methods The entire promoter region of YPO1635 was amplified and cloned into the pRW50 vector containing a promoterless lacZ reporter gene.The recombinant LacZ reporter plasmid was transformed into the wild-type strain (WT) and the phoP mutant strain (ΔphoP),respectively,to measure the promoter activity (the β-galactosidase activity) of the target gene in WT and ΔphoP by using the β-galactosidase enzyme assay system.Total RNAs were extracted from WT and ΔphoP strains,and primer extension assay was employed to detect the promoter activity by examining the amount of primer extension products of YPO1635 in WT and ΔphoP.Results The LacZ fusion results showed that the transcription of YPO1635 was positively regulated by PhoP under L-TMH and brain-heart infusion(BHI) conditions,but it was not regulated in H-TMH medium.The primer extension assay detected two transcriptional start sites located at 90 and 118 bp upstream of the translation initiation site of phoP,named P1 and P2,respectively.Under low Mg2+ TMH conditions,the promoter activity of P1 rather than P2 was positively regulated by PhoP.Under high Mg2+ TMH conditions,the promoter activities of both P1 and P2 showed no obvious difference in the WT and ΔphoP strains.Under rich BHI conditions,both promoters were under negative control of PhoP.Conclusion Different autoregualtion patterns of PhoP/PhoQ under different growth conditions would help Y.pestis to quickly adapt to the changing living environment.关键词
鼠疫耶尔森菌/YPO1635/phoP/调控Key words
Yersinia pestis/YPO1635/phoP/regulation分类
生物科学引用本文复制引用
张义全,方海红,刘磊,黄新祥,杨瑞馥,周冬生,杨慧盈..不同培养条件下鼠疫菌PhoP/PhoQ的自调控模式研究[J].军事医学,2017,41(5):373-376,4.基金项目
军队医学科技青年培育计划资助项目(15QNP086) （15QNP086）
国家自然科学基金面上资助项目(31430006) （31430006）
