Vibrio parahaemolyticus CalR down regulates the thermostable direct hemolysin (TDH) gene transcription and thereby inhibits hemolytic activity.
Vibrio parahaemolyticus CalR down regulates the thermostable direct hemolysin (TDH) gene transcription and thereby inhibits hemolytic activity.
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DOI：
10.1016/j.gene.2017.03.001
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发表时间：
2017-05
期刊：
影响因子：
3.5
通讯作者：
Yiquan Zhang;Ying Zhang;He Gao;Lingyu Zhang;Zhe Yin;Xin-xiang Huang;Dongsheng Zhou;Huiying Yang;Wenhui Yang;Li Wang
中科院分区：
文献类型：
--
作者：
Yiquan Zhang;Ying Zhang;He Gao;Lingyu Zhang;Zhe Yin;Xin-xiang Huang;Dongsheng Zhou;Huiying Yang;Wenhui Yang;Li Wang
TDH基因编码的TDH是V.控制各种生物活性的副溶血性，如溶血活性、细胞毒性和肠毒性。在Wagatsuma琼脂上归因于TDH的溶血活性被称为神奈川现象（KP）。所有KP阳性菌株均含有dh 1和tdh 2基因，但dh 2基因主要负责KP。CalR是一种调节蛋白，最初被鉴定为蜂群运动和T3 SS 1基因表达的阻遏物。副溶血性本研究采用qRT-PCR、引物延伸、LacZ融合、溶血表型、EMSA和DNA酶I足迹分析等方法研究了CalR对tdh 2的调控作用。结果表明，His-CalR保护tdh 2上游224 ~ 318 bp的区域不被DNase I消化，在tdh 2上游42 bp处检测到转录起始位点，其转录活性被CalR抑制。KP试验结果表明，V.副溶血性链球菌也在CalR的阴性对照下。结果表明，CalR是tdh 2转录的阻遏物，从而抑制了V.副溶血性
TDH, encoded bytdhgene, is a major virulent determinant ofV. parahaemolyticusthat controls various biological activities, such as hemolytic activity, cytotoxicity, and enterotoxicity. The hemolytic activity on Wagatsuma agar ascribed to TDH is called Kanagawa phenomenon (KP). All KP positive strains containtdh1andtdh2genes, buttdh2is predominantly responsible for KP. CalR is a regulatory protein that was originally identified as a repressor of swarming motility and T3SS1 gene expression inV. parahaemolyticus. In the present study, the regulation oftdh2by CalR was investigated using a set of experiments including qRT-PCR, primer extension, LacZ fusion, hemolytic phenotype, EMSA, and DNase I footprinting assays. The results showed that His-CalR protected a single region from 224 bp to 318 bp upstream oftdh2against DNase I digestion, and a transcriptional start site located at 42 bp upstream oftdh2was detected and its transcribed activity was inhibited by CalR. Moreover, the KP test results showed that the hemolytic activity ofV. parahaemolyticusis also under negative control of CalR. The data demonstrated that CalR is a repressor of thetdh2transcription and thereby inhibits the hemolytic activity ofV. parahaemolyticus.