Translocation of the Helicobacter pylori CagA protein in gastric epithelial cells by a type IV secretion apparatus
Translocation of the Helicobacter pylori CagA protein in gastric epithelial cells by a type IV secretion apparatus
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DOI：
10.1046/j.1462-5822.2000.00043.x
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发表时间：
2000-04-01
影响因子：
3.4
通讯作者：
Meyer, TF
中科院分区：
文献类型：
--
作者：
Backert, S;Ziska, E;Meyer, TF
幽门螺杆菌是最常见的细菌病原体之一，感染了大约50%的世界人口。幽门螺杆菌致病性岛（PAI）的存在与胃疾病有关。我们提出的证据表明，由细胞毒素相关基因A （cagA）编码的幽门螺杆菌蛋白在感染的上皮细胞中易位和磷酸化。从感染AGS细胞中分离的蛋白的二维凝胶电泳（2-DE）显示幽门螺杆菌菌株特异性和时间依赖性的酪氨酸磷酸化和去磷酸化几种125-135 kDa和75-80 kDa蛋白。免疫印迹、基质辅助激光解吸/电离质谱（MALDI-MS）、细胞分离和共聚焦显微镜研究表明，125-135 kDa蛋白中的一个代表幽门螺杆菌CagA蛋白，该蛋白被转运到宿主细胞膜和细胞质中。在幽门螺杆菌的cag PAI中，由virB4、virB7、virB10、virB11和virD4组成的IV型分泌装置中，CagA的易位依赖于功能CagA基因和毒力（vir）基因。我们的研究结果支持这样一种观点，即幽门螺杆菌积极易位毒力决定因子，包括CagA，它可能参与各种胃病的发展。
Helicobacter pylori is one of the most common bacterial pathogens, infecting about 50% of the world population. The presence of a pathogenicity island (PAI) in H. pylori has been associated with gastric disease. We present evidence that the H. pylori protein encoded by the cytotoxin-associated gene A (cagA) is translocated and phosphorylated in infected epithelial cells. Two-dimensional gel electrophoresis (2-DE) of proteins isolated from infected AGS cells revealed H. pylori strain-specific and time-dependent tyrosine phosphorylation and dephosphorylation of several 125-135 kDa and 75-80 kDa proteins. Immunoblotting studies, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), cell fractionation and confocal microscopy demonstrated that one of the 125-135 kDa proteins represents the H. pylori CagA protein, which is translocated into the host cell membrane and the cytoplasm. Translocation of CagA was dependent on functional cagA gene and virulence (vir) genes of a type IV secretion apparatus composed of virB4, virB7, virB10, virB11 and virD4 encoded in the cag PAI of H. pylori. Our findings support the view that H. pylori actively translocates virulence determinants, including CagA, which could be involved in the development of a variety of gastric disease.