HrpG regulates type II secretory proteins in Xanthomonas axonopodis pv. citri
HrpG regulates type II secretory proteins in Xanthomonas axonopodis pv. citri
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DOI：
10.1007/s10327-008-0075-7
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发表时间：
2008-02
影响因子：
1.2
通讯作者：
A. Yamazaki;H. Hirata;S. Tsuyumu
中科院分区：
文献类型：
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作者：
A. Yamazaki;H. Hirata;S. Tsuyumu
HrpG是黄单胞菌（Xanthomonasspp.）的一种双组分反应调节因子样蛋白，是Ⅲ型分泌系统（T3 SS）的关键调节因子。在油菜黄单胞菌（X.campestrispv.vesicatoria）中，具有单个氨基酸取代（HrpG*）的HrpG获得了即使在营养丰富的条件下也诱导T3 SS相关基因表达的能力。在这项研究中，我们研究了HrpG在分泌蛋白合成中的作用，使用HrpG* 菌株NA-1的X.axonopodispv.citri（Xac NA-1），柑橘溃疡病的病原体。通过II型分泌系统（T2 SS）分泌的11种蛋白质由HrpG* 诱导。在蛋白质组学分析中，11种蛋白质中的6种被鉴定为胞外酶，其他的被鉴定为菌毛生物发生相关蛋白、IV型相关蛋白、两种假设蛋白和一种保守的假设蛋白。对这些蛋白质的进一步分析显示，编码所有11种蛋白质的基因被HrpG* 上调，尽管它们对HrpXct依赖性具有不同的表达模式。数据表明，HrpG，T3 SS的关键调节因子，也作为Xac NA-1中通过T2 SS分泌的某些蛋白质的正调节因子。
HrpG, a two-component response regulator-like protein, is a key regulator of the type III secretion system (T3SS) inXanthomonasspp. InX.campestrispv.vesicatoria, HrpG with a single amino acid substitution (HrpG*) gains the ability to induce the expression of T3SS-related genes even under nutrient-rich conditions. In this study, we investigated the role of HrpG in the synthesis of the secretory protein using HrpG* in strain NA-1 ofX.axonopodispv.citri(Xac NA-1), a causal agent of citrus canker. Eleven proteins secreted via a type II secretion system (T2SS) were induced by HrpG*. In proteomic analyses, six of the 11 proteins were identified as extracellular enzymes, and the others as a fimbrial biogenesis-related protein, a type IV-related protein, two hypothetical proteins, and a conserved hypothetical protein. Further analysis of these proteins revealed that the genes coding all 11 proteins were upregulated by HrpG*, even though they had different expression patterns for HrpXct-dependency. The data indicated that HrpG, a key regulator of T3SS, also acts as a positive regulator of certain proteins secreted via a T2SS in Xac NA-1.