Helicobacter pylori Chaperone-Like Protein CagT Plays an Essential Role in the Translocation of CagA into Host Cells
Helicobacter pylori Chaperone-Like Protein CagT Plays an Essential Role in the Translocation of CagA into Host Cells
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幽门螺杆菌伴侣蛋白 CagT 在 CagA 易位至宿主细胞中发挥重要作用
DOI：
10.4014/jmb.1202.02025
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发表时间：
2012-10-01
影响因子：
2.8
通讯作者：
Zou, Quanming
中科院分区：
文献类型：
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作者：
Ding Honglei;Zeng, Hao;Zou, Quanming
大多数含有cag致病岛（PAL）的幽门螺杆菌菌株与感染者更严重的胃病有关。cag PAL由27种蛋白质组成，其中一些组分是CagA易位到宿主细胞以及诱导促炎细胞因子（如白细胞介素-8（IL-8））所需的;然而，大多数组分的确切功能仍然未知或表征不佳。在这项研究中，我们证明，CagT（HP 0532），这是一个重要的结构组成部分的齿轮派装置，起着重要的作用，在易位的CagA到宿主上皮细胞。除了位于细菌表面之外，CagT还部分位于内膜中，在那里它充当伴侣样蛋白并促进CagA易位。然而，CagT分泌细胞培养上清液的免疫沉淀分析没有检测到。同时，CagT与宿主细胞IL-8的导入有关。这些结果表明，CagT表达的内部和外部的细菌膜，其中它作为一个独特的IV型分泌系统的组成部分，参与CagA分泌和齿轮派装置组装。
Most of the Helicobacter pylori strains containing the cag pathogenicity island (PAL) have been associated with more severe gastric disease in infected humans. The cag PAL is composed of 27 proteins, and some of the components are required for CagA translocation into host cells as well as induction of proinflammatory cytokines, such as interleukin-8 (IL-8); however, the exact function of most of the components remains unknown or poorly characterized. In this study, we demonstrated that CagT (HP0532), which is an essential structural component of the cog PAI apparatus, plays an important role in the translocation of CagA into host epithelial cells. In addition to being located on the bacterial surface, CagT is also partially localized in the inner membrane, where it acts as a chaperone-like protein and promotes CagA translocation. However, CagT secretion was not detected by immunoprecipitation analysis of cell culture supernatants. Meanwhile, CagT was related to the introduction of IL-8 of the host cell. These results suggest that CagT is expressed on both the inner and outer bacterial membranes, where it serves as a unique type IV secretion system component that is involved in CagA secretion and cog PAI apparatus assembly.