A chemosensory-like histidine kinase is dispensable for chemotaxis in vitro but regulates the virulence of Borrelia burgdorferi through modulating the stability of RpoS.
A chemosensory-like histidine kinase is dispensable for chemotaxis in vitro but regulates the virulence of Borrelia burgdorferi through modulating the stability of RpoS.
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DOI：
10.1371/journal.ppat.1011752
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发表时间：
2023-11
期刊：
影响因子：
6.7
通讯作者：
中科院分区：
文献类型：
--
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莱姆病病原体伯氏疏螺旋体（Borrelia burgdorferi）具有多拷贝的趋化性蛋白，包括两种趋化性组氨酸激酶（CHK），CheA 1和CheA 2。我们之前的研究表明，CheA 2是一种真正的CHK，是趋化性所必需的;然而，CheA 1的作用仍然是神秘的。本报告首先比较了区分CheA 1和CheA 2的结构特征，然后提供证据表明CheA 1是控制B毒力的非典型CHK。通过调节螺旋体的关键转录调节因子RpoS的稳定性来抑制伯氏螺旋体。首先，使用绿色荧光蛋白（GFP）标签的显微镜分析表明，CheA 1具有独特的和动态的细胞定位。第二，功能丧失的研究表明，CheA 1是不需要的体外趋化性，尽管共享一个高的序列和结构相似性，其对应物从其他细菌。第三，使用针接种的小鼠感染研究表明，CheA 1的缺失突变体（cheA 1 mut）能够在免疫缺陷小鼠中建立全身感染，但在免疫活性小鼠中不能这样做，尽管突变体可以在接种部位存活长达28天。蜱和小鼠感染研究进一步表明，CheA 1是蜱定植和收购，但必不可少的蜱传播。最后，结合免疫印迹、蛋白质周转、诱变和RNA-seq分析的机制研究揭示，CheA 1的耗尽影响RpoS稳定性，导致几种RpoS调节的毒力因子的表达减少（即，OspC、BBK 32和DbpA），可能是由于clpX和lon蛋白酶表达失调。对感染小鼠皮肤组织的大量RNA-seq分析进一步显示，cheA 1 mut不能诱导小鼠TNF-α、IL-10、IL-1β和ccl 2表达，这四种细胞因子是莱姆病发展和B的重要细胞因子。伯氏轮回。这些结果揭示了CheA 1在调节毒力因子表达中的独特作用和调控机制，为理解B的调控网络提供了新的见解。burgdorferi。莱姆病是一种由伯氏疏螺旋体引起的传染病，通过受感染的黑腿蜱叮咬传播给人类。它是北美和欧洲最常见的蜱传疾病。B。伯氏菌是一种高度侵入性的细菌，它可以游动并深入组织，引起广泛的疾病，包括关节炎、脑膜炎和迁移性肌肉骨骼疼痛。这种侵袭性是由螺旋体感知和响应周围环境的能力驱动的，这种感知和响应是由信号转导与位于细胞两端的复杂的感觉蛋白阵列相结合发起的。B的基因组。Burgdorferi编码趋化相关基因的多个拷贝，并且这些基因中的许多基因的功能仍然未知。在这份报告中，我们专注于破译的作用之一的趋化性组氨酸激酶，CheA 1。我们的研究结果揭示了一种新的监管贡献的CheA 1的感染性生命周期和发病机制的B。burgdorferi。
As an enzootic pathogen, the Lyme disease bacterium Borrelia burgdorferi possesses multiple copies of chemotaxis proteins, including two chemotaxis histidine kinases (CHK), CheA1 and CheA2. Our previous study showed that CheA2 is a genuine CHK that is required for chemotaxis; however, the role of CheA1 remains mysterious. This report first compares the structural features that differentiate CheA1 and CheA2 and then provides evidence to show that CheA1 is an atypical CHK that controls the virulence of B. burgdorferi through modulating the stability of RpoS, a key transcriptional regulator of the spirochete. First, microscopic analyses using green-fluorescence-protein (GFP) tags reveal that CheA1 has a unique and dynamic cellular localization. Second, loss-of-function studies indicate that CheA1 is not required for chemotaxis in vitro despite sharing a high sequence and structural similarity to its counterparts from other bacteria. Third, mouse infection studies using needle inoculations show that a deletion mutant of CheA1 (cheA1mut) is able to establish systemic infection in immune-deficient mice but fails to do so in immune-competent mice albeit the mutant can survive at the inoculation site for up to 28 days. Tick and mouse infection studies further demonstrate that CheA1 is dispensable for tick colonization and acquisition but essential for tick transmission. Lastly, mechanistic studies combining immunoblotting, protein turnover, mutagenesis, and RNA-seq analyses reveal that depletion of CheA1 affects RpoS stability, leading to reduced expression of several RpoS-regulated virulence factors (i.e., OspC, BBK32, and DbpA), likely due to dysregulated clpX and lon protease expression. Bulk RNA-seq analysis of infected mouse skin tissues further show that cheA1mut fails to elicit mouse tnf-α, il-10, il-1β, and ccl2 expression, four important cytokines for Lyme disease development and B. burgdorferi transmigration. Collectively, these results reveal a unique role and regulatory mechanism of CheA1 in modulating virulence factor expression and add new insights into understanding the regulatory network of B. burgdorferi. Lyme disease is an infectious disease caused by the bacterium Borrelia burgdorferi which is transmitted to humans through the bite of infected blacklegged ticks. It is the most commonly reported tick-borne illness in North America and Europe. B. burgdorferi is a highly invasive bacterium that can swim and penetrate deep into tissues to cause a wide range of disorders including arthritis, meningitis, and migratory musculoskeletal pain. This invasiveness is driven by the ability of the spirochete to sense and respond to its surrounding initiated by signal transduction coupled with a sophisticated array of sensory proteins located at both cell ends. The genome of B. burgdorferi encodes multiple copies of chemotaxis-related genes and the function of many of these genes remains unknown. In this report, we focus on deciphering the role of one of the chemotaxis histidine kinases, CheA1. Our results reveal a novel regulatory contribution of CheA1 to the infectious life cycle and pathogenesis of B. burgdorferi.
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影响因子：
9.3
作者：
Ramesh G;Santana-Gould L;Inglis FM;England JD;Philipp MT
通讯作者：
Philipp MT
影响因子：
3.1
作者：
Brown, JP;Zachary, JF;Wooten, RM
通讯作者：
Wooten, RM
影响因子：
64.5
作者：
Bilwes, AM;Alex, LA;Simon, MI
通讯作者：
Simon, MI
影响因子：
3.6
作者：
Coleman JL;Toledo A;Benach JL
通讯作者：
Benach JL
DOI：
10.3390/pathogens10030281
发表时间：
2021-03-02
期刊：
Pathogens (Basel, Switzerland)
影响因子：
--
作者：
Anderson C;Brissette CA
通讯作者：
Brissette CA