Motility control through an anti-activation mechanism in Agrobacterium tumefaciens.
Motility control through an anti-activation mechanism in Agrobacterium tumefaciens.
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DOI：
10.1111/mmi.14823
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发表时间：
2021-11
影响因子：
3.6
通讯作者：
Fuqua C
中科院分区：
文献类型：
--
作者：
Alakavuklar MA;Heckel BC;Stoner AM;Stembel JA;Fuqua C
许多细菌可以从自由生活的浮游状态迁移到附着的生物膜存在。调控兼性植物病原菌根癌农杆菌的这一转变的一个因素是Exor-ChvG-ChvI系统。周质Exor调节ChvG-ChvI双组分系统的活性以响应环境胁迫，最显著的是低pH。ChvI影响数百个基因，包括VI型分泌、毒力、生物膜形成和鞭毛运动所需的基因。以前的研究表明，激活的ChvG-ChvI可以抑制大多数II类和III类鞭毛生物发生基因的表达，但不能抑制主要的运动调节基因VISN、visR和rem的表达。在这项研究中，我们描述了Exor-ChvG-ChvI和VisNR-Rem通路的整合。我们分离了非运动性ΔExor突变体的运动性抑制因子，从而鉴定了之前未注释的MIRA基因，编码一个76个氨基酸的蛋白质。我们报道了Mira蛋白直接与Rem DNA结合域相互作用，隔离Rem并阻止运动性基因激活。ChvG-ChvI途径激活Mira的表达，Mira的升高足以阻断运动。这项研究揭示了Exor-ChvG-ChvI途径如何阻止根癌农杆菌的鞭毛运动。Mira在根瘤菌目的其他成员中也是保守的，这表明了类似的运动性调节机制。根癌农杆菌是一种植物病原菌，它通过一个复杂的双组分调控系统对低pH、胁迫环境做出反应。这种调控系统可以完全抑制鞭毛对细菌的运动，在本研究中，我们定义了这种抑制的机制，并发现了一种新的小蛋白调节因子，可以阻止鞭毛基因的表达。
Many bacteria can migrate from a free-living, planktonic state to an attached, biofilm existence. One factor regulating this transition in the facultative plant pathogen Agrobacterium tumefaciens is the ExoR-ChvG-ChvI system. Periplasmic ExoR regulates activity of the ChvG-ChvI two-component system in response to environmental stress, most notably low pH. ChvI impacts hundreds of genes, including those required for type VI secretion, virulence, biofilm formation, and flagellar motility. Previous studies revealed that activated ChvG-ChvI represses expression of most of class II and class III flagellar biogenesis genes, but not the master motility regulator genes visN, visR, and rem. In this study, we characterized the integration of the ExoR-ChvG-ChvI and VisNR-Rem pathways. We isolated motile suppressors of the non-motile ΔexoR mutant and thereby identified the previously unannotated mirA gene encoding a 76 amino acid protein. We report that the MirA protein interacts directly with the Rem DNA-binding domain, sequestering Rem and preventing motility gene activation. The ChvG-ChvI pathway activates mirA expression and elevated mirA is sufficient to block motility. This study reveals how the ExoR-ChvG-ChvI pathway prevents flagellar motility in A. tumefaciens. MirA is also conserved among other members of the Rhizobiales suggesting similar mechanisms of motility regulation. Agrobacterium tumefaciens is a plant pathogen that responds to low pH, stressful environments via a complex two-component regulatory system. This regulatory system can completely inhibit bacterial locomotion by flagella, and in this study, we define the mechanism for this inhibition and identify a novel small protein regulator that blocks flagellar gene expression.
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影响因子：
3.2
作者：
Heckel, Brynn C.;Tomlinson, Amelia D.;Fuqua, Clay
通讯作者：
Fuqua, Clay
影响因子：
5.6
作者：
Jones, DT
通讯作者：
Jones, DT
DOI：
10.1073/pnas.0704843104
发表时间：
2007-10-16
影响因子：
11.1
作者：
Chen, Guozhou;Jeffrey, Philip D.;Chen, Lingling
通讯作者：
Chen, Lingling
影响因子：
5.6
作者：
KLOSE, KE;WEISS, DS;KUSTU, S
通讯作者：
KUSTU, S
影响因子：
5.8
作者：
Hanson, Jack;Yang, Yuedong;Zhou, Yaoqi
通讯作者：
Zhou, Yaoqi