Study of signal transduction and physiological role for the formation of lipid domaines

• Project/Area Number: 16K15056
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Integrative animal science
• Research Institution: Kagoshima University
• Principal Investigator: Fujita Akikazu 鹿児島大学, 農水産獣医学域獣医学系, 教授 (60282232)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2016: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 脂質 / 脂肪 / 微細局在 / 電子顕微鏡 / オートファジー / 酵母 / 急速凍結 / 凍結割断 / 生体膜 / 微細分布 / オートファゴソーム / ホスファチジルイノシタイド / フリーズフラクチャー / ナノスケール / イノシトールリン脂質 / 細胞内オルガネラ / シグナル伝達 / 免疫電子顕微鏡法

Outline of Final Research Achievements

Phosphatidylinositol 4-phosphate (PtdIns(4)P) itself has been found to serve as an essential signalling molecule in the cell organelles where it is involved in the control of membrane trafficking, and signal transduction pathways, via direct interaction with PtdIns(4)P-binding protein. To completely understand the autophagy, it is important to determine the localization of PtdIns(4)P in the autophagosome. To analyze the distribution of PtdIns(4)P at a nanoscale, we employed the quick-freezing and freeze-fracture replica labeling (QF-FRL) method. We found that the localization of PtdIns(4)P in the luminal leaflet in the biological membrane. We also showed using mutant yeast cells that PtdIns 4-kinases Pik1p and Stt4p have essential roles in the autophagosome formation and autophagosome-vacuole fusion in yeast, respectively.

Academic Significance and Societal Importance of the Research Achievements

私たちは脂質を観る新たな技術（急速凍結・凍結割断レプリカ標識法）を開発し、電子顕微鏡を用いて生体膜における微細構造レベルでの膜脂質の分布解析を可能にした。この技術は膜脂質の機能解明に大きく貢献し、生命機能解明への新たなアプローチを提供できると考えている。さらにこのアプローチによりもたらされた知見は、脂質代謝異常をはじめ様々な疾患の原因や病態の解明に役立つものと期待している。

Research Products

• [Int'l Joint Research] Harvard University(米国)
• [Int'l Joint Research] Harvard University(米国)
• [Journal Article] Nanoscale domain formation of phosphatidylinositol 4-phosphate in the plasma and vacuolar membranes of living yeast cells. (2018)
  • Author(s): Tomioku KN, Shigekuni M, Hayashi H, Yoshida A, Futagami T, Tamaki H, Tanabe K, Fujita A.
  • Journal Title: Eur J Cell Biol Volume: 印刷中 Issue: 4 Pages: 269-278
  • DOI: 10.1016/j.ejcb.2018.03.007
  • Peer Reviewed
• [Journal Article] Immunoelectron Microscopy of Gangliosides (2018)
  • Author(s): Tsuji Takuma、Fujita Akikazu、Fujimoto Toyoshi
  • Journal Title: Methods in molecular biology Volume: 1804 Pages: 231-239
  • DOI: 10.1007/978-1-4939-8552-4_11
  • ISBN: 9781493985517, 9781493985524
  • Peer Reviewed
• [Journal Article] Phosphatidylinositol 4‐phosphate on Rab7‐positive autophagosomes revealed by the freeze‐fracture replica labeling (2018)
  • Author(s): Kurokawa Yuna、Yoshida Akane、Fujii Emi、Tomioku Kanna、Hayashi Hiroki、Tanabe Kenji、Fujita Akikazu
  • Journal Title: Traffic Volume: 20 Issue: 1 Pages: 82-95
  • DOI: 10.1111/tra.12623
  • Peer Reviewed
• [Journal Article] Segregation of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate into distinct microdomains on the endosome membrane (2017)
  • Author(s): Yoshida Akane、Hayashi Hiroki、Tanabe Kenji、Fujita Akikazu
  • Journal Title: Biochimica et Biophysica Acta (BBA) - Biomembranes Volume: 1859 Issue: 10 Pages: 1880-1890
  • DOI: 10.1016/j.bbamem.2017.06.014
  • Peer Reviewed
• [Journal Article] Nanoscale analysis reveals agonist-sensitive and heterogeneous pools of phosphatidylinositol 4-phosphate in the plasma membrane. (2016)
  • Author(s): Yoshida, A., Shigekuni, M., Tanabe, K., Fujita, A.
  • Journal Title: Biochim. Biophys. Acta Volume: 1858 Issue: 6 Pages: 1298-1305
  • DOI: 10.1016/j.bbamem.2016.03.011
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] PtdIns4KIIα generates endosomal PtdIns(4)P and is required for receptor sorting at early endosomes. (2016)
  • Author(s): Henmi, Y., Morikawa, Y., Oe, N., Ikeda, N., Fujita, A., Takei, K., Minogue, S., Tanabe, K.
  • Journal Title: Mol. Biol. Cell Volume: 27 Issue: 6 Pages: 990-1001
  • DOI: 10.1091/mbc.e15-08-0564
  • Peer Reviewed / Open Access
• [Presentation] オートファゴソームにおけるホスファチルイノシトール4リン酸（PtdIns(4)P）の微細局在 (2018)
  • Author(s): 黒川夕奈、林宏樹、富奥甘奈、藤田秋一
  • Organizer: 日本獣医学会
• [Book] 獣医生化学 (2016)
  • Author(s): 藤田秋一
  • Total Pages: 13
  • Publisher: 朝倉書店
• [Remarks] 研究者詳細 - 藤田 秋一 - 鹿児島大学
  • URL: http://ris.kuas.kagoshima-u.ac.jp/html/100005509_ja.html
• [Remarks] 鹿児島大学共同獣医学部分子病態学分野
  • URL: http://www.vet.kagoshima-u.ac.jp/kadai/V-Mol/bunshibyoutai01/Welcome.html