HpaP, a novel regulatory protein with ATPase and phosphatase activity, contributes to full virulence in Xanthomonas campestris pv. campestris
HpaP, a novel regulatory protein with ATPase and phosphatase activity, contributes to full virulence in Xanthomonas campestris pv. campestris
复制标题
HpaP 是一种具有 ATP 酶和磷酸酶活性的新型调节蛋白，有助于 Xanthomonas Campestris pv. 的完全毒力。
DOI：
10.1111/1462-2920.14046
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发表时间：
2018-04-01
影响因子：
5.1
通讯作者：
Lu, Guang-Tao
中科院分区：
文献类型：
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作者：
Cui, Ping;Li, Rui-Fang;Lu, Guang-Tao
植物病原细菌野油菜黄单胞菌致病变种（Xanthomonascampestrispv.）白菜型油菜（Xcc）致病依赖于III型分泌系统（T3SS）。Xcc T3SS的蛋白质由hrp（过敏反应和致病性）基因编码，并且其表达主要由调节剂HrpG和HrpX控制。在这里，我们描述了一个以前未知的调节蛋白（命名为HpaP），它在Xcc中的hrp基因表达和毒力中起着重要作用的鉴定和表征。hpaP的完全缺失表明Xcc的毒力和HR（过敏反应）诱导降低，细胞运动性和应激耐受性改变。全局转录组分析显示，大多数hrp基因下调hpaP突变体，表明HpaP正调控hrp基因。GUS活性分析表明，HpaP通过调控hrpX的表达来调控hrp基因的表达。生化分析表明，HpaP蛋白具有ATP酶和磷酸酶活性。而进一步定点突变的PTP环（蛋白酪氨酸磷酸酶签名）的HpaP的保守残基导致的损失，磷酸酶活性和调节活性的毒力和HR。两者合计，研究结果确定了一个新的调节蛋白，控制HRP基因的表达和毒力在XCC。
The ability of the bacterial phytopathogen Xanthomonas campestris pv. campestris (Xcc) to cause disease is dependent on the type III secretion system (T3SS). Proteins of the Xcc T3SS are encoded by hrp (hypersensitive response and pathogenicity) genes and whose expression is mainly controlled by the regulators HrpG and HrpX. Here, we describe the identification and characterization of a previously unknown regulatory protein (named HpaP), which plays important role in hrp gene expression and virulence in Xcc. Clean deletion of hpaP demonstrated reduced virulence and HR (hypersensitive response) induction of Xcc and alterations in cell motility and stress tolerance. Global transcriptome analyses revealed that most hrp genes were down regulated in the hpaP mutant, suggesting HpaP positively regulates hrp genes. GUS activity assays implied that HpaP regulates the expression of hrp genes via controlling the expression of hrpX. Biochemical analyses revealed that HpaP protein had both ATPase and phosphatase activity. While further site-directed mutagenesis of conserved residues in the PTP loop (a protein tyrosine phosphatase signature) of HpaP resulted in the loss of both phosphatase activity and regulatory activity in virulence and HR. Taken together, the findings identify a new regulatory protein that controls hrp gene expression and virulence in Xcc.