Functional characterization of two type III secretion systems of Vibrio parahaemolyticus
Functional characterization of two type III secretion systems of Vibrio parahaemolyticus
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DOI：
10.1128/iai.72.11.6659-6665.2004
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发表时间：
2004-11-01
影响因子：
3.1
通讯作者：
Honda, T
中科院分区：
文献类型：
--
作者：
Park, KS;Ono, T;Honda, T
副溶血性弧菌是一种革兰氏阴性海洋细菌，是世界范围内引起食源性胃肠炎的原因。临床副溶血性弧菌菌株RIMD 2210633的最新基因组测序鉴定了III型分泌系统（TTSS）的两组基因，TTSS 1和TTSS 2。在这里，我们从RIMD 2210633中构建了一系列突变株，以确定这两个假定的TTSS装置是否有功能。与亲本和TTSS2相关突变株相比，TTSS1基因缺失突变株的细胞毒活性显著降低。在采用兔回肠袢试验的肠毒性试验中，通过缺失TTSS 2相关基因减少了肠液蓄积，而TrSS 1相关突变体引起的肠液蓄积水平与亲本相似。VopD是一种在TTSS1区域附近编码的蛋白质，是耶尔森氏菌YopD的同源物，以TTSS1依赖的方式分泌。相比之下，VopP，这是由2号染色体上的致病岛编码，是同源的耶尔森氏菌YopP，分泌通过TTSS2途径。这些结果提供了副溶血性弧菌TTSS作为分泌系统发挥作用的证据，并可能在微生物的致病性中发挥作用。这是第一次在弧菌属中报道功能性TTSS。TTSS装置基因同源物的存在被证明在其他弧菌，如溶藻弧菌，哈氏弧菌，和管氏弧菌，这表明一些其他弧菌也含有TTSS和TTSS在这些生物体中的蛋白质分泌在与真核细胞的相互作用过程中的作用。
Vibrio parahaemolyticus, a gram-negative marine bacterium, is a worldwide cause of food-borne gastroenteritis. Recent genome sequencing of the clinical V. parahaemolyticus strain RIMD2210633 identified two sets of genes for the type III secretion system (TTSS), TTSS1 and TTSS2. Here, we constructed a series of mutant strains from RIMD2210633 to determine whether the two putative TTSS apparatus are functional. The cytotoxic activity of mutant strains having a deletion in one of the TTSS1 genes was significantly decreased compared with that of the parent and TTSS2-related mutant strains. In an enterotoxicity assay with the rabbit ilea] loop test, intestinal fluid accumulation was diminished by deletion of the TTSS2-related genes while TrSS1-related mutants caused a level of fluid accumulation similar to that of the parent. VopD, a protein encoded in the proximity of the TTSS1 region and a homologue of the Yersinia YopD, was secreted in a TTSS1-dependent manner. In contrast, VopP, which is encoded by a pathogenicity island on chromosome 2 and is homologous to the Yersinia YopP, was secreted via the TTSS2 pathway. These results provide evidence that V. parahaemolyticus TTSSs function as secretion systems and may have a role in the pathogenicity of the organism. This is the first report of functional TTSSs in Vibrio species. The presence of TTSS apparatus gene homologues was demonstrated in other vibrios, such as Vibrio alginolyticus, Vibrio harveyi, and Vibrio tubiashii, suggesting that some other vibrios also contain TTSS and that the TTSS has a role in protein secretion in those organisms during interaction with eukaryotic cells.