Contribution of glucan-binding protein A to firm and stable biofilm formation by Streptococcus mutans.
Contribution of glucan-binding protein A to firm and stable biofilm formation by Streptococcus mutans.
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DOI：
10.1111/omi.12085
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发表时间：
2015-06
影响因子：
3.7
通讯作者：
Y. Matsumi;K. Fujita;Y. Takashima;K. Yanagida;Y. Morikawa;M. Matsumoto-Nakano
中科院分区：
文献类型：
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作者：
Y. Matsumi;K. Fujita;Y. Takashima;K. Yanagida;Y. Morikawa;M. Matsumoto-Nakano
变形链球菌（Streptococcus mutans）的葡聚糖结合蛋白（Gbps）是龋病的主要病原体，其通过由gtfB、gtfC和gtfD编码的葡糖基转移酶（GTF）的作用介导由蔗糖合成的葡聚糖的结合。几种胁迫蛋白，包括DnaK和GroEL编码的DnaK和GroEL，与环境胁迫耐受性有关。通过关注编码GTF和应激蛋白的基因的表达水平来分析Gbp表达对生物膜形成的贡献。使用GbpA-、GbpB-和GbpC-缺陷型突变株和亲本株MT 8148进行生物膜形成测定。通过逆转录-定量聚合酶链反应（RT-qPCR）评价gtfB、gtfC、gtfD、dnaK和groEL的表达水平。此外，这些Gbp缺陷型突变株形成的生物膜的结构进行了观察，使用共聚焦激光扫描显微镜（CLSM）。生物膜形成试验结果表明，GbpA缺陷型突变株（AD 1）形成的量与亲本菌株几乎相同，而GbpB和GbpC缺陷型突变株产生的量低于MT 8148。RT-qPCR检测结果显示，AD 1中gtfB、dnaK和groEL的表达均高于MT 8148。CLSM还显示AD 1形成的生物膜结构与亲本菌株相比存在显著差异。这些结果表明，GbpA的缺陷影响控制生物膜形成的基因的表达，表明其作为蛋白质对于牢固和稳定的生物膜形成的重要性。
Glucan-binding proteins (Gbps) of Streptococcus mutans, a major pathogen of dental caries, mediate the binding of glucans synthesized from sucrose by the action of glucosyltransferases (GTFs) encoded by gtfB, gtfC, and gtfD. Several stress proteins, including DnaK and GroEL encoded by dnaK and groEL, are related to environmental stress tolerance. The contribution of Gbp expression to biofilm formation was analyzed by focusing on the expression levels of genes encoding GTFs and stress proteins. Biofilm-forming assays were performed using GbpA-, GbpB-, and GbpC-deficient mutant strains and the parental strain MT8148. The expression levels of gtfB, gtfC, gtfD, dnaK, and groEL were evaluated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Furthermore, the structure of biofilms formed by these Gbp-deficient mutant strains was observed using confocal laser scanning microscopy (CLSM). Biofilm-forming assay findings demonstrated that the amount formed by the GbpA-deficient mutant strain (AD1) was nearly the same as that by the parental strain, while the GbpB- and GbpC-deficient mutant strains produced lower amounts than MT8148. Furthermore, RT-qPCR assay results showed that the expressions of gtfB, dnaK, and groEL in AD1 were elevated compared with MT8148. CLSM also revealed that the structure of biofilm formed by AD1 was prominently different compared with that formed by the parental strain. These results suggest that a defect in GbpA influences the expression of genes controlling biofilm formation, indicating its importance as a protein for firm and stable biofilm formation.