An Extracytoplasmic Function Sigma/Anti-Sigma Factor System Regulates β-Glucanase Expression in Tannerella forsythia in Response to Fusobacterium nucleatum Sensing.
An Extracytoplasmic Function Sigma/Anti-Sigma Factor System Regulates β-Glucanase Expression in Tannerella forsythia in Response to Fusobacterium nucleatum Sensing.
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细胞质外功能 Sigma/Anti-Sigma 因子系统调节连翘 Tannerella forsythia 中 β-葡聚糖酶的表达，以响应具核梭杆菌的传感。
DOI：
10.1128/jb.00313-22
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发表时间：
2022
影响因子：
3.2
通讯作者：
Sharma,Ashu
中科院分区：
文献类型：
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作者：
Honma,Kiyonobu;Sasaki,Haruka;Hamada,Nobushiro;Sharma,Ashu
牙周病病原菌Tannerella lasthia表达一种β-葡聚糖酶（TfGlcA），其表达受口腔桥细菌具核梭杆菌（Fusobacterium nucleatum）的诱导，TfGlcA裂解β-葡聚糖释放葡萄糖，葡萄糖可作为F.有核细胞和其他共生生物。编码推定的细胞质外功能（ECF）σ因子和FecR样抗σ因子的双基因簇已被识别在aTfGlcA操纵子的上游。我们表征并分析了这些推定的ECF σ和反σ因子在TfGlcA表达调节中的作用。为此目的，构建缺失突变体并分析β-葡聚糖酶表达。此外，大肠杆菌产生的ECF σ因子重组蛋白的转录和DNA结合活性进行了评价。结果表明，重组蛋白通过glcA启动子启动RNA聚合酶核心酶来促进转录。此外，与亲本菌株中的那些相比，β-葡聚糖酶表达水平在ECF σ因子缺失突变体中显著降低，而在FecR抗σ因子缺失突变体中显著增加。在与F.具核体全细胞或细胞提取物。最后，测定了T.拜特产生β-葡聚糖酶的水平。黄曲霉属共生膜中的核质生物量。综上所述，我们鉴定了一个β-葡聚糖酶操纵子调控系统，该系统包含一个ECF sigma因子（TfSigG）和一个响应于F的同源FecR样抗sigma因子。重要的是，以前的研究表明，F。nucleatum与T.利用T拜特水解产生的葡萄糖进行脱硫。利用F.核质在这项研究中，我们发现，一个由ECF sigma因子TfSigG和FecR样抗sigma因子TfFecR组成的调节系统负责响应于F.核质，表明该系统在T.和F.核质研究结果表明，针对β-葡聚糖酶活性或TfSigG/TfFecR系统的小分子抑制剂作为治疗牙菌斑形成和牙周炎的药物的开发和潜在用途。
The periodontal pathogen Tannerella forsythia expresses a β-glucanase (TfGlcA) whose expression is induced in response to Fusobacterium nucleatum, a bridge bacterium of the oral cavity.TfGlcA cleaves β-glucans to release glucose, which can serve as a carbon source for F. nucleatum and other cohabiting organisms. A two-gene cluster encoding a putative extracytoplasmic function (ECF) sigma factor and a FecR-like anti-sigma factor has been recognized upstream of aTfGlcA operon. We characterized and analyzed the role of these putative ECF sigma and anti-sigma factors in the regulation ofTfGlcA expression. For this purpose, deletion mutants were constructed and analyzed for β-glucanase expression. In addition, an Escherichia coli-produced ECF sigma factor recombinant protein was evaluated for transcriptional and DNA binding activities. The results showed that the recombinant protein promoted transcription by the RNA polymerase core enzyme from theglcApromoter. Furthermore, in comparison to those in the parental strain, the β-glucanase expression levels were significantly reduced in the ECF sigma-factor deletion mutant and increased significantly in the FecR anti-sigma factor deletion mutant. The levels did not change in the mutants following coincubation with the F. nucleatum whole cells or cell extracts. Finally, the levels of β-glucanase produced byT. forsythiastrains paralleled F. nucleatum biomass in cobiofilms. In conclusion, we identified a β-glucanase operon regulatory system inT. forsythiacomprising an ECF sigma factor (TfSigG) and a cognate FecR-like anti-sigma factor responsive to F. nucleatum and potentially other stimuli.IMPORTANCEPrevious studies have shown that F. nucleatum forms robust biofilms withT. forsythiautilizing glucose from the hydrolysis of β-glucans byT. forsythiaβ-glucanase, induced by F. nucleatum. In this study, we showed that a regulatory system comprising of an ECF sigma factor,TfSigG, and a FecR-like anti-sigma factor,TfFecR, is responsible for the β-glucanase induction in response to F. nucleatum, suggesting that this system plays roles in the mutualistic interactions ofT. forsythiaand F. nucleatum. The findings suggest the development and potential utility of small-molecule inhibitors targeting the β-glucanase activity or theTfSigG/TfFecR system as therapeutic drugs against dental plaque formation and periodontitis.