Regulation of the gene expression of the type IX secretion component proteins in Porphyromonas gingivalis

2015 Fiscal Year Final Research Report

• Project/Area Number: 25462925
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Pathobiological dentistry/Dental radiology
• Research Institution: Nagasaki University
• Principal Investigator: YUKITAKE Hideharu 長崎大学, 医歯薬学総合研究科(歯学系), 技術職員 (30380984)
• Co-Investigator(Renkei-kenkyūsha): NAKAYAMA Koji 長崎大学, 医歯薬学総合研究科(歯学系), 教授 (80150473)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 歯周病細菌 / 分泌調節メカニズム / ９型分泌機構 / 二成分制御系 / ECFシグマ因子 / ゲルシフトアッセイ

Outline of Final Research Achievements

Porphyromonas gingivalis secretes potent pathogenic proteases, gingipains, via the type IX secretion system (T9SS). We found that the PorY-PorX-SigP cascade is involved in the regulation of T9SS. Surface plasmon resonance (SPR) analysis revealed a direct interaction between PorY and PorX. PorY autophosphorylated and transferred a phosphoryl group to PorX in the presence of Mn2+, demonstrating that PorX and PorY act as a response regulator and a histidine kinase, respectively, of a two component system (TCS). T9SS component-encoding genes were down-regulated in a mutant deficient in a putative extracytoplasmic function (ECF) sigma factor, SigP, similar to the porX mutant. SigP could bind to the putative promoter regions of T9SS component-encoding genes. SigP was lacking in the porX mutant. PorX could bind to SigP. Together, these results indicate that the PorXY TCS regulates T9SS-mediated protein secretion via the SigP ECF sigma factor.

Free Research Field

口腔細菌学