Tetratricopeptide Repeat Protein-Associated Proteins Contribute to the Virulence of Porphyromonas gingivalis
Tetratricopeptide Repeat Protein-Associated Proteins Contribute to the Virulence of Porphyromonas gingivalis
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DOI：
10.1128/iai.01448-09
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发表时间：
2010-06-01
影响因子：
3.1
通讯作者：
Nakayama, Koji
中科院分区：
文献类型：
--
作者：
Kondo, Yoshio;Ohara, Naoya;Nakayama, Koji
牙龈卟啉单胞菌是牙周病最重要的病原微生物之一。我们在先前的研究中发现，PG 1385（TprA）蛋白，一种四肽重复（TPR）蛋白，在置于小鼠皮下室中的牙龈卟啉单胞菌野生型细胞中上调，并且tprA突变体在小鼠皮下脓肿模型中的毒性明显降低（M. Yoshimura等人，口腔微生物Immunol·23：413-418，2008）。在本研究中，我们研究了置于小鼠皮下室中的tprA突变细胞的基因表达谱，发现与野生型相比，tprA突变细胞中的PG 2102（tapA）、PG 2101（tapB）和PG 2100（tapC）等9个基因表达下调。一组tapA，tapB，和tapC基因的突变体的表达也下调，在体外培养与丰富的脑心脏输液培养基。TprA蛋白具有三个TPR基序，称为蛋白质-蛋白质相互作用模块。酵母双杂交系统分析和体外蛋白结合试验的免疫沉淀和表面等离子体共振检测表明，TprA蛋白可以结合TapA和TapB蛋白。TprA和TapB蛋白位于周质空间，而TapA，这似乎是一个C-末端结构域家族蛋白，位于外膜。我们构建了tapA、tapB和tapC单突变体和tapA-tapB-tapC缺失突变体。在小鼠皮下感染实验中，所有突变体的毒力均低于野生型。这些结果表明TprA、TapA、TapB和TapC协同参与牙龈卟啉单胞菌的毒力。
Porphyromonas gingivalis is one of the most etiologically important microorganisms in periodontal disease. We found in a previous study that PG1385 (TprA) protein, a tetratricopeptide repeat (TPR) protein, was upregulated in P. gingivalis wild-type cells placed in a mouse subcutaneous chamber and that a tprA mutant was clearly less virulent in the mouse subcutaneous abscess model (M. Yoshimura et al., Oral Microbiol. Immunol. 23: 413-418, 2008). In the present study, we investigated the gene expression profile of tprA mutant cells placed in a mouse subcutaneous chamber and found that 9 genes, including PG2102 (tapA), PG2101 (tapB), and PG2100 (tapC) genes, were downregulated in the tprA mutant compared with those in the wild type. Expression of a cluster of tapA, tapB, and tapC genes of the mutant was also downregulated in an in vitro culture with enriched brain heart infusion medium. The TprA protein has three TPR motifs known as a protein-protein interaction module. Yeast two-hybrid system analysis and in vitro protein binding assays with immunoprecipitation and surface plasmon resonance detection revealed that the TprA protein could bind to TapA and TapB proteins. TprA and TapB proteins were located in the periplasmic space, whereas TapA, which appeared to be one of the C-terminal domain family proteins, was located at the outer membrane. We constructed tapA, tapB, and tapC single mutants and a tapA-tapB-tapC deletion mutant. In the mouse subcutaneous infection experiment, all of the mutants were less virulent than the wild type. These results suggest that TprA, TapA, TapB, and TapC are cooperatively involved in P. gingivalis virulence.