Characterization of the outer membrane protein complex in the Por secretion pathway

• Project/Area Number: 23592715
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Morphological basic dentistry
• Research Institution: The Nippon Dental University
• Principal Investigator: SAIKI Keitarou 日本歯科大学, 生命歯学部, 講師 (30297973)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2013: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2012: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2011: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: 歯周病 / タンパク分泌 / 歯周炎 / タンパク質分泌 / 慢性歯周炎

Outline of Final Research Achievements

Porphyromonas gingivalis, the etiologic agent of chronic periodontitis, secretes C-terminal domain (CTD) proteins, which are involved in virulence and proliferation of this bacterium, via the Por secretion pathway (PorSP). PorSP is composed of steps such as passage through the outer membrane via the CTD-dependent Por secretion system (PorSS), cleavage of their CTDs by the CTD signal peptidase PG0026, glycolipid-conjugation, and anchorage to the outer cell membrane and/or the extracellular vesicles. PG0026 is one of the CTD proteins and secreted via PorSS, but undergoes no successive modifications. In this study, I found that PG0026 anchors to the cell surface by interacting with outer membrane protein PG27 that is involved in the glycolipid modification of CTD proteins, and functions in processing of other CTD proteins such as gingipains. This study also demonstrates the complex formation of the outer membrane proteins in PorSP.

Research Products

• [Journal Article] Assembly and function of PG27/LptO, PG0026, and HagA in the secretion and modification system of C-terminal domain proteins (2014)
  • Author(s): Keitarou Saiki & Kiyoshi Konishi
  • Journal Title: J. Oral Biosci. Volume: 56 Issue: 4 Pages: 115-119
  • DOI: 10.1016/j.job.2014.07.001
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Porphyromonas gingivalis C-terminal signal peptidase PG0026 and HagA interact with outer membrane protein PG27/LptO (2014)
  • Author(s): K. Saiki, K. Konishi
  • Journal Title: Molecular Oral Microbiology Volume: 29 Issue: 1 Pages: 32-44
  • DOI: 10.1111/omi.12043
  • Peer Reviewed
• [Journal Article] Strategies for targeting the gingipain secretion system of Porphyromonas gingivalis (2012)
  • Author(s): Keitarou Saiki, Kiyoshi Konishi
  • Journal Title: Journal of Oral Biosciences Volume: 54 Pages: 155-159
  • Peer Reviewed
• [Presentation] Porphyromonas gingivalisのC末シグナルペプチダーゼとヘマグルチニンと外膜タンパクPG27との結合 (2014)
  • Author(s): 才木桂太郎、古西清司
  • Organizer: 第87回日本細菌学会総会
  • Place of Presentation: タワーホール船堀、東京都
• [Presentation] ジンジパインの分泌機構
  • Author(s): 才木桂太郎、古西清司
  • Organizer: 第55回歯科基礎医学会学術集会「サテライトシンポジウム10」
  • Place of Presentation: 岡山コンベンションセンター、岡山県
• [Presentation] 歯周病原因菌の病原因子分泌に関与するPG27/LptO蛋白の欠失変異および抑圧変異の解析と推定βバレル構造の検証
  • Author(s): 才木 桂太郎
  • Organizer: 第84回日本生化学会大会
  • Place of Presentation: 京都国際会館（京都）
• [Presentation] Porphyromonas gingivalisのジンジパイン分泌系を標的とした研究戦略
  • Author(s): 才木 桂太郎
  • Organizer: 第53回歯科基礎医学会学術大会ならびに総会
  • Place of Presentation: 長良川国際会議場（岐阜）
• [Presentation] Deletion and suppressor mutation analyses of Sov that functions in a novel protein secretion system
  • Author(s): 才木 桂太郎
  • Organizer: 第85回日本細菌学会総会
  • Place of Presentation: 長崎ブリックホール（長崎）