School of Life Science, Wuchang University of Technology, Wuhan, P.R. China.
State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, P.R. China.
J Basic Microbiol. 2019 May;59(5):535-541. doi: 10.1002/jobm.201800325. Epub 2019 Feb 21.
Vibrio parahaemolyticus V110 is a marine origin pathogen infecting shrimp. Its resistance to oxidative stress is important for its survival in the complex marine ecosystems. vpa0768 (katG1) and vpa0453 (katG2) were previously found to contribute to the resistance against H O and isopropylbenzene. Our data showed that purified KatG2 and KatG1 possessed similar activity for hydrolyzing H O at 37 °C. The transcription of katG genes was induced by H O , cumene, and tert-butyl hydroperoxide (TBHP). The fold change of katG2 transcripts induced by isopropylbenzene was significantly higher than that of katG1. oxyR and rpoS are well-known regulatory genes which control the anti-oxidative and general stress response pathways, respectively. Deletion of rpoS resulted pathways, respectively. Deletion of rpoS resulted in abolishing the induction of katGs by the peroxides, and oxyR deletion only weakened the expression of the two genes. These results indicate that the two katGs encoding active enzymes are both inducible, but differ in their inducer preference. RpoS and oxyR are required for the full expression of katGs, but other unknown sensing regulators could be involved in the oxidative stress response besides OxyR.
副溶血弧菌 V110 是一种感染虾的海洋来源病原体。其对氧化应激的抵抗力对于其在复杂海洋生态系统中的生存至关重要。vpa0768（katG1）和 vpa0453（katG2）先前被发现有助于抵抗 H2O2 和异丙苯。我们的数据表明，在 37°C 下，纯化的 KatG2 和 KatG1 对 H2O2 的水解活性相似。katG 基因的转录受 H2O2、枯烯和叔丁基过氧化氢 (TBHP) 诱导。异丙苯诱导的 katG2 转录的倍数变化明显高于 katG1。oxyR 和 rpoS 是众所周知的调节基因，分别控制抗氧化和一般应激反应途径。rpoS 的缺失导致了氧自由基和异丙苯诱导的 katGs 的表达被消除，而 oxyR 的缺失仅削弱了这两个基因的表达。这些结果表明，编码活性酶的两个 katG 均为可诱导的，但诱导剂偏好不同。RpoS 和 oxyR 是 katGs 完全表达所必需的，但除了 OxyR 之外，其他未知的感应调节剂可能参与了氧化应激反应。
