Guan Yunpeng, Yin Kaiyu, Zhou Mian, Yang Minjun, Zhang Yuanxing, Liu Xiaohong, Wang Qiyao
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, China.
FEMS Microbiol Lett. 2018 Feb 1;365(4). doi: 10.1093/femsle/fny007.
Edwardsiella piscicida is a gram-negative bacterial pathogen invading a wide range of fish species. Response regulator EsrB is essential for the activation of type III and type VI secretion systems (T3/T6SS). In this study, proteomes of the wild-type E. piscicida EIB202 and ΔesrB mutant strains were compared to identify the regulon components of EsrB cultured in DMEM allowing T3/T6SS expression. As a result, 19 proteins showed different expression, which were identified to be associated with T3/T6SS, related to amino acid transport and metabolism, and energy production. Particularly, GlnA, a glutamine synthetase essential for ammonia assimilation and glutamine biosynthesis from glutamate, was found to be regulated negatively by EsrB. Moreover, GlnA affected bacterial growth in vitro and bacterial colonization in vivo. Collectively, our results indicated that EsrB plays important roles in regulating the expression of metabolic pathways and virulence genes, including glutamine biosynthesis in E. piscicida during infection.
杀鱼爱德华氏菌是一种革兰氏阴性细菌病原体，可侵袭多种鱼类。应答调节因子EsrB对于III型和VI型分泌系统（T3/T6SS）的激活至关重要。在本研究中，对野生型杀鱼爱德华氏菌EIB202和ΔesrB突变株的蛋白质组进行了比较，以鉴定在允许T3/T6SS表达的DMEM中培养的EsrB的调控子成分。结果，有19种蛋白质表现出不同的表达，这些蛋白质被鉴定为与T3/T6SS相关、与氨基酸转运和代谢以及能量产生有关。特别地，谷氨酰胺合成酶GlnA对于氨同化和从谷氨酸合成谷氨酰胺至关重要，发现它受到EsrB的负调控。此外，GlnA影响体外细菌生长和体内细菌定植。总的来说，我们的结果表明，EsrB在调节代谢途径和毒力基因的表达中起重要作用，包括在感染期间杀鱼爱德华氏菌中的谷氨酰胺生物合成。
