Identification and characterization of a type III secretion-associated chaperone in the type III secretion system 1 of Vibrio parahaemolyticus
Identification and characterization of a type III secretion-associated chaperone in the type III secretion system 1 of Vibrio parahaemolyticus
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DOI：
10.1111/j.1574-6968.2009.01607.x
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发表时间：
2009-07-01
影响因子：
2.1
通讯作者：
Honda, Takeshi
中科院分区：
文献类型：
--
作者：
Akeda, Yukihiro;Okayama, Kanna;Honda, Takeshi
副溶血性弧菌引起人类肠胃炎。该生物体的基因组测序显示，它有两套III型分泌系统，T3 SS 1和T3 SS 2，这两套系统对其致病性都很重要。然而，通过T3 SS分泌蛋白的机制尚不清楚。许多效应物的特征是它们需要特异性伴侣以通过T3 SS有效递送;然而，在副溶血性弧菌的T3 SS中没有实验鉴定出伴侣。在这项研究中，我们确定了候选T3 SS 1相关分子伴侣的基因组序列数据，并检查其在效应分泌/易位和结合到其同源底物的作用。从这些实验中，我们得出结论，有一个T3 S相关的伴侣，VecA，细胞毒性T3 SS 1依赖性效应，VepA。使用下拉和分泌测定的进一步分析表征了包含VepA上的前30-100个氨基酸的伴侣结合结构域和包含前5-20个氨基酸的氨基末端分泌信号。这些发现将为阐明副溶血性弧菌T3 SS 1如何分泌其特异性效应物提供策略。
Vibrio parahaemolyticus causes human gastroenteritis. Genomic sequencing of this organism has revealed that it has two sets of type III secretion systems, T3SS1 and T3SS2, both of which are important for its pathogenicity. However, the mechanism of protein secretion via T3SSs is unknown. A characteristic of many effectors is that they require specific chaperones for efficient delivery via T3SSs; however, no chaperone has been experimentally identified in the T3SSs of V. parahaemolyticus. In this study, we identified candidate T3SS1-associated chaperones from genomic sequence data and examined their roles in effector secretion/translocation and binding to their cognate substrates. From these experiments, we concluded that there is a T3S-associated chaperone, VecA, for a cytotoxic T3SS1-dependent effector, VepA. Further analysis using pulldown and secretion assays characterized the chaperone-binding domain encompassing the first 30-100 amino acids and an amino terminal secretion signal encompassing the first 5-20 amino acids on VepA. These findings will provide a strategy to clarify how the T3SS1 of V. parahaemolyticus secretes its specific effectors.