Role of the universal stress protein UspA of Salmonella in growth arrest, stress and virulence
Role of the universal stress protein UspA of Salmonella in growth arrest, stress and virulence
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DOI：
10.1016/j.micpath.2006.09.002
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发表时间：
2007-01-01
影响因子：
3.8
通讯作者：
Khan, C. M. Anjam
中科院分区：
文献类型：
--
作者：
Liu, Wen-Tssann;Karavolos, Michail H.;Khan, C. M. Anjam
病原菌利用各种机制来抵抗它们在宿主内外活跃生长期间以及生长停滞期间遇到的一连串压力。对沙门氏菌基因组序列的电子筛选显示，鼠伤寒沙门氏菌LT2具有属于通用应激蛋白A(USPA)家族的同源物。我们通过构建LacZ融合蛋白来评估USPA在鼠伤寒沙门氏菌C5中的转录谱，结果表明USPA是由代谢、氧化和温度应激诱导的。在进入稳定期的细胞中，转录水平最高，这与在大肠杆菌中的表达模式一致。该蛋白被提纯为与GST(USPA(F))的融合，针对UspAF的抗体显示，在应激和生长停滞的细胞中，蛋白质水平升高。在鼠伤寒沙门氏菌C5中，USPA失活，导致对胁迫条件的敏感性增加。此外，USPA对沙门氏菌在小鼠体内的毒力做出了重要贡献，从而强调了应激抗性调节在宿主致病性和生存中的重要性。皇冠版权所有(C)2006由爱思唯尔有限公司出版。保留所有权利。
Pathogenic bacteria employ a variety of mechanisms to resist a barrage of stresses they encounter during active growth in or outside the host as well as during growth stasis. An in silico screen of the Salmonella genome sequence revealed that Salmonella typhimurium LT2 possesses a homologue belonging to the universal stress protein A (UspA) family. We assessed the transcriptional profile of uspA in S. typhimurium C5 by constructing a lacZ fusion revealing that uspA is induced by metabolic, oxidative, and temperature stresses. The highest transcriptional levels occurred in cells entering stationary phase, an observation consistent with expression patterns in Escherichia coli. The protein was purified as a fusion with GST (UspA(F)) and antibodies raised against UspAF revealed elevated protein levels in stressed and growth-arrested cells. Inactivation of uspA in S. typhimurium C5, lead to increased susceptibility to stress conditions. Furthermore, UspA makes an important contribution to the in vivo virulence of Salmonella in mice thus highlighting the importance of stress resistance regulation in pathogenicity and survival within the host. Crown Copyright (c) 2006 Published by Elsevier Ltd. All rights reserved.