Expression of Pseudomonas aeruginosa CupD fimbrial genes is antagonistically controlled by RcsB and the EAL-containing PvrR response regulators.
Expression of Pseudomonas aeruginosa CupD fimbrial genes is antagonistically controlled by RcsB and the EAL-containing PvrR response regulators.
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DOI：
10.1371/journal.pone.0006018
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发表时间：
2009-06-23
期刊：
影响因子：
3.7
通讯作者：
Filloux A
中科院分区：
文献类型：
--
作者：
Mikkelsen H;Ball G;Giraud C;Filloux A
铜绿假单胞菌是一种革兰氏阴性致病菌，具有高度的适应潜力，允许在广泛的宿主或小生境中增殖。它也是人类急性和慢性生物膜相关感染的病原体。参与细胞表面菌毛组装的三个cup基因簇（cupA-C）已显示参与铜绿假单胞菌菌株PAO 1或PAK的生物膜形成。在PA 14分离株中，在致病性岛PAPI-I内鉴定出第四个簇，命名为cupD，并且可能有助于该菌株的更高毒力。cupA基因的表达受HNS样蛋白MvaT控制，而cupB和cupC基因受RocS 1A 1 R双组分系统控制。在这项研究中，我们表明，cupD基因的表达是积极控制的反应调节RcsB。因此，CupD菌毛在细胞表面组装，这导致许多表型，如小菌落形态型，增加的生物膜形成和降低的运动性。这些行为与固着细菌的生活方式是相容的。已知强直和固着生活方式之间的平衡与细胞内c-di-GMP水平有关，高水平有利于生物膜形成。我们发现，EAL结构域含有PvrR反应调节抵消活性的RcsB cupD基因表达。PvrR的作用可能涉及通过磷酸二酯酶活性的c-di-GMP降解，证实了这种第二信使在细菌生活方式之间的平衡中的关键作用。RcsB和PvrR之间的调节网络仍有待阐明，但它是一个潜在的模型系统，研究两种生活方式之间的平衡如何受到有利于非紧张性生活方式的治疗药物的影响。这将使病原体可用于免疫系统或常规抗生素治疗。
Pseudomonas aeruginosa is a gram-negative pathogenic bacterium with a high adaptive potential that allows proliferation in a broad range of hosts or niches. It is also the causative agent of both acute and chronic biofilm-related infections in humans. Three cup gene clusters (cupA-C), involved in the assembly of cell surface fimbriae, have been shown to be involved in biofilm formation by the P. aeruginosa strains PAO1 or PAK. In PA14 isolates, a fourth cluster, named cupD, was identified within a pathogenicity island, PAPI-I, and may contribute to the higher virulence of this strain. Expression of the cupA genes is controlled by the HNS-like protein MvaT, whereas the cupB and cupC genes are under the control of the RocS1A1R two-component system. In this study, we show that cupD gene expression is positively controlled by the response regulator RcsB. As a consequence, CupD fimbriae are assembled on the cell surface, which results in a number of phenotypes such as a small colony morphotype, increased biofilm formation and decreased motility. These behaviors are compatible with the sessile bacterial lifestyle. The balance between planktonic and sessile lifestyles is known to be linked to the intracellular levels of c-di-GMP with high levels favoring biofilm formation. We showed that the EAL domain-containing PvrR response regulator counteracts the activity of RcsB on cupD gene expression. The action of PvrR is likely to involve c-di-GMP degradation through phosphodiesterase activity, confirming the key role of this second messenger in the balance between bacterial lifestyles. The regulatory network between RcsB and PvrR remains to be elucidated, but it stands as a potential model system to study how the equilibrium between the two lifestyles could be influenced by therapeutic agents that favor the planktonic lifestyle. This would render the pathogen accessible for the immune system or conventional antibiotic treatment.
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DOI：
10.1073/pnas.060030097
发表时间：
2000-04-25
影响因子：
11.1
作者：
Rashid, MH;Kornberg, A
通讯作者：
Kornberg, A
影响因子：
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Villemur, R
影响因子：
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作者：
Alibaud, Laeticia;Koehler, Thilo;Cosson, Pierre
通讯作者：
Cosson, Pierre
影响因子：
2.6
作者：
Hoang, TT;Kutchma, AJ;Schweizer, HP
通讯作者：
Schweizer, HP
影响因子：
3.2
作者：
Rao, Feng;Yang, Ye;Liang, Zhao-Xun
通讯作者：
Liang, Zhao-Xun