HtrA of Borrelia burgdorferi Leads to Decreased Swarm Motility and Decreased Production of Pyruvate.
HtrA of Borrelia burgdorferi Leads to Decreased Swarm Motility and Decreased Production of Pyruvate.
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DOI：
10.1128/mbio.01136-18
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发表时间：
2018-07-10
期刊：
影响因子：
6.4
通讯作者：
Benach JL
中科院分区：
文献类型：
--
作者：
Coleman JL;Toledo A;Benach JL
伯氏疏螺旋体HtrA（HtrABb）是一种丝氨酸蛋白酶，其靶向受损或不正确折叠的蛋白质。在我们以前的研究中，HtrABb特异性降解碱性膜蛋白BmpD，趋化性磷酸酶CheX和外膜蛋白P66。此外，HtrABb降解毒力因子BB 0323和细胞外基质纤连蛋白和聚集蛋白聚糖的组分。对HtrAB b过表达的伯氏B. burgdorferi菌株（A3 HtrAOE）进行的基于蛋白质组学的分析（二维差异凝胶电泳[2-D DIGE]、液相色谱-质谱[LC-MS]）显示，与野生型B. burgdorferi相比，P66的蛋白水平降低，证实了其作为HtrAB B b底物的状态。Hbb是一种P66-DNA结合转录因子，被HtrABb特异性降解，为两者在P66调控中的作用提供了支持性证据。A3 HtrAOE在群体测定中表现出降低的运动性，这可能是HtrABb过量与其对P66的酶特异性之间的联系。然而，ΔP66菌株在群体测定中没有降低的运动性，否定了该蛋白的作用。蛋白质组学分析还鉴定了糖酵解途径的三种酶，甘油醛-3-磷酸脱氢酶（GAPDH）、甘油-3-磷酸脱氢酶（GPDH）和甘油激酶（GK），以及一种参与碳水化合物代谢的酶，二磷酸-果糖-6-磷酸1-磷酸转移酶，其在A3 HtrAOE中被还原。与这些糖酵解酶的蛋白质水平降低一致，A3 HtrAOE也缺乏丙酮酸的产生。我们提出了一个模型的作用，HtrAB B在有助于降低代谢活性的B.伯氏疏螺旋体。作为一种媒介传播的细菌，伯氏B. burgdorferi在从蜱传播到哺乳动物时必须重塑其蛋白质含量。蛋白质水解是一种机制，重塑可以完成。HtrABb降解许多蛋白质，这些蛋白质的消失可能有助于使这种生物体进入低代谢活性阶段。
Borrelia burgdorferi HtrA (HtrABb) is a serine protease that targets damaged or improperly folded proteins. In our previous studies, HtrABb specifically degraded basic membrane protein BmpD, chemotaxis phosphatase CheX, and outer membrane protein P66. In addition, HtrABb degrades virulence factor BB0323 and components of the extracellular matrix fibronectin and aggrecan. A proteomics-based analysis (two-dimensional difference gel electrophoresis [2-D DIGE], liquid chromatography-mass spectrometry [LC-MS]) of an HtrABb-overexpressing strain of B. burgdorferi (A3HtrAOE) revealed that protein levels of P66 were reduced in comparison to wild-type B. burgdorferi, confirming its status as an HtrABb substrate. Hbb, a P66-DNA-binding transcription factor, was specifically degraded by HtrABb, providing supportive evidence for a role for both in the regulation of P66. A3HtrAOE exhibited reduced motility in swarm assays, a possible link between overabundance of HtrABb and its enzymatic specificity for P66. However, the ΔP66 strain did not have reduced motility in the swarm assays, negating a role for this protein. The proteomics analyses also identified three enzymes of the glycolytic pathway, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glycerol-3-phosphate dehydrogenase (GPDH), and glycerol kinase (GK), and one enzyme involved in carbohydrate metabolism, diphosphate-fructose-6-phosphate 1-phosphotransferase, which were reduced in A3HtrAOE. Consistent with its reduced protein levels of these glycolytic enzymes, A3HtrAOE was also deficient in production of pyruvate. We propose a model for a role for HtrABb in contributing to a decrease in metabolic activity of B. burgdorferi. Being a vector-borne bacterium, B. burgdorferi must remodel its protein content as it transfers from tick to mammal. Proteolysis is a mechanism whereby remodeling can be accomplished. HtrABb degrades a number of proteins whose disappearance may help in preparing this organism for a stage of low metabolic activity.