A systematic analysis of the role of GGDEF-EAL domain proteins in virulence and motility in Xanthomonas oryzae pv. oryzicola.
A systematic analysis of the role of GGDEF-EAL domain proteins in virulence and motility in Xanthomonas oryzae pv. oryzicola.
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DOI：
10.1038/srep23769
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发表时间：
2016-04-07
影响因子：
4.6
通讯作者：
Sun W
中科院分区：
文献类型：
--
作者：
Wei C;Jiang W;Zhao M;Ling J;Zeng X;Deng J;Jin D;Dow JM;Sun W
第二信使c-di-GMP涉及革兰氏阴性菌的生活方式和毒力的各个方面的调节。环状二GMP由具有GGDEF结构域的二鸟苷酸环化酶形成，并由具有EAL或HD-GYP结构域的磷酸二酯酶降解。具有串联GGDEF-EAL结构域的蛋白质存在于许多细菌中，其中它们可能参与c-di-GMP周转或充当酶失活的c-di-GMP效应物。在这里，我们报告了一个系统的研究，11 GGDEF-EAL蛋白的调节作用，黄单胞菌pv。oryzicola是引起水稻细菌性条斑病的重要病原菌。突变分析显示，XOC 2335和XOC 2393正调控细菌的游泳运动，而XOC 2102、XOC 2393和XOC 4190负调控细菌的滑动运动。与野生型相比，胞内c-di-GMP水平较高的ΔXOC_2335/XOC_2393突变体和ΔXOC_4190突变体在压力接种后对水稻的毒力降低。体外纯化的XOC_4190和XOC_2102几乎没有或没有二鸟苷酸环化酶或磷酸二酯酶活性，这与ΔXOC_4190中未改变的c-di-GMP浓度一致。然而，这两种蛋白质都可以以高亲和力与c-di-GMP结合，表明其作为c-di-GMP效应物的潜在作用。总的来说，我们的研究结果推进了对c-di-GMP信号传导及其与重要水稻病原体毒力的联系的理解。
The second messenger c-di-GMP is implicated in regulation of various aspects of the lifestyles and virulence of Gram-negative bacteria. Cyclic di-GMP is formed by diguanylate cyclases with a GGDEF domain and degraded by phosphodiesterases with either an EAL or HD-GYP domain. Proteins with tandem GGDEF-EAL domains occur in many bacteria, where they may be involved in c-di-GMP turnover or act as enzymatically-inactive c-di-GMP effectors. Here, we report a systematic study of the regulatory action of the eleven GGDEF-EAL proteins in Xanthomonas oryzae pv. oryzicola, an important rice pathogen causing bacterial leaf streak. Mutational analysis revealed that XOC_2335 and XOC_2393 positively regulate bacterial swimming motility, while XOC_2102, XOC_2393 and XOC_4190 negatively control sliding motility. The ΔXOC_2335/XOC_2393 mutant that had a higher intracellular c-di-GMP level than the wild type and the ΔXOC_4190 mutant exhibited reduced virulence to rice after pressure inoculation. In vitro purified XOC_4190 and XOC_2102 have little or no diguanylate cyclase or phosphodiesterase activity, which is consistent with unaltered c-di-GMP concentration in ΔXOC_4190. Nevertheless, both proteins can bind to c-di-GMP with high affinity, indicating a potential role as c-di-GMP effectors. Overall our findings advance understanding of c-di-GMP signaling and its links to virulence in an important rice pathogen.