The mechanistic insight into the ribosome splitting event to initiate the RQC pathway

• Project/Area Number: 19K06481
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 43010:Molecular biology-related
• Research Institution: The University of Tokyo (2021); Tohoku University (2019-2020)
• Principal Investigator: Matsuo Yoshitaka 東京大学, 医科学研究所, 准教授 (00725252)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2021: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: リボソーム / ユビキチン化 / 品質管理 / 翻訳

Outline of Research at the Start

細胞は遺伝子発現の過程で生じた異常産物を認識・分解する様々な仕組みを備えている。翻訳停滞に起因する品質管理機構は、mRNA上で停滞したリボソームがサブユニットへと乖離することで誘導される。途中まで合成された新生ペプチド鎖は乖離した60Sサブユニット上に保持され、E3ユビキチンリガーゼ Ltn1 によってユビキチン化後、プロテアソームによって分解される。停滞したリボソームを認識し、終止コドン非依存に乖離させる過程は、一連の反応を誘導するか否かを決定する重要なステップであるが、その分子機構については未だ不明な点が多い。そこで本研究課題では、停滞したリボソームの認識・乖離機構の解明を目指す。

Outline of Final Research Achievements

Ribosome-associated quality control (RQC) represents a rescue pathway in eukaryotic cells triggered upon translational stalling. However, the mechanism underlying the ubiquitin-dependent ribosome dissociation remain poorly understood.
In the project, we established the in vitro system, which enabled the reconstitution of Hel2-dependent poly-ubiquitination of collided tri-ribosomes. This system showed that the collided ribosome were efficiently recognized by Hel2 and ubiquitinated. Subsequently, the Slh1 helicase subunit of the RQC trigger (RQT) complex preferentially dissociates the first stalled poly-ubiquitinated ribosome in an ATP-dependent manner. Together, these findings provide fundamental mechanistic insights into RQC and its physiological role in maintaining cellular protein homeostasis.

Academic Significance and Societal Importance of the Research Achievements

タンパク質の合成途中のエラーによる翻訳停止はタンパク質の機能の重大な欠陥を引き起こし、タンパク質の恒常性の破綻につながります。タンパク質の恒常性の破綻は、更に不良なタンパク質の蓄積やオルガネラの損傷、シグナル伝達経路の撹乱など、広範な細胞機能の障害を引き起こすため、アルツハイマー病やパーキンソン病などの神経変性疾患の原因になると考えられています。本研究では、細胞の持つ品質管理の仕組みを分子レベルで解明しました。本成果は、神経変性疾患の原因となる異常タンパク質の合成を効率的に抑制する治療薬の開発に貢献する事が期待されます。

Research Products

• [Int'l Joint Research] University of California, Berkeley(米国)
• [Int'l Joint Research] University of Munich(ドイツ)
• [Journal Article] The ribosome collision sensor Hel2 functions as preventive quality control in the secretory pathway (2021)
  • Author(s): Matsuo Yoshitaka、Inada Toshifumi
  • Journal Title: Cell Reports Volume: 34 Issue: 12 Pages: 108877-108877
  • DOI: 10.1016/j.celrep.2021.108877
  • Peer Reviewed / Open Access
• [Journal Article] The ubiquitination-deubiquitination cycle on the ribosomal protein eS7A is crucial for efficient translation (2021)
  • Author(s): Takehara Yuka、Yashiroda Hideki、Matsuo Yoshitaka、Zhao Xian、Kamigaki Akane、Matsuzaki Tetsuo、Kosako Hidetaka、Inada Toshifumi、Murata Shigeo
  • Journal Title: iScience Volume: 24 Issue: 3 Pages: 102145-102145
  • DOI: 10.1016/j.isci.2021.102145
  • NAID: 120007182109
  • Peer Reviewed / Open Access
• [Journal Article] Ribosomal protein S7 ubiquitination during ER stress in yeast is associated with selective mRNA translation and stress outcome (2020)
  • Author(s): Matsuki Yasuko、Matsuo Yoshitaka、Nakano Yu、Iwasaki Shintaro、Yoko Hideyuki、Udagawa Tsuyoshi、Li Sihan、Saeki Yasushi、Yoshihisa Tohru、Tanaka Keiji、Ingolia Nicholas T.、Inada Toshifumi
  • Journal Title: Scientific Reports Volume: 10 Issue: 1 Pages: 19669-19669
  • DOI: 10.1038/s41598-020-76239-3
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] RQT complex dissociates ribosomes collided on endogenous RQC substrate SDD1 (2020)
  • Author(s): Matsuo Yoshitaka、Tesina Petr、Nakajima Shizuka、Mizuno Masato、Endo Akinori、Buschauer Robert、Cheng Jingdong、Shounai Okuto、Ikeuchi Ken、Saeki Yasushi、Becker Thomas、Beckmann Roland、Inada Toshifumi
  • Journal Title: Nature Structural & Molecular Biology Volume: 27 Issue: 4 Pages: 323-332
  • DOI: 10.1038/s41594-020-0393-9
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The Ccr4-Not complex monitors the translating ribosome for codon optimality. (2020)
  • Author(s): Robert Buschauer*, Yoshitaka Matsuo* (*Co-first author), Takato Sugiyama, Ying-Hsin Chen, Najwa Alhusaini, Thomas Sweet, Ken Ikeuchi, Jingdong Cheng, Yasuko Matsuki, Risa Nobuta, Andrea Gilmozzi, Otto Berninghausen, Petr Tesina, Thomas Becker, Jeff Coller, Toshifumi Inada and Roland Beckmann.
  • Journal Title: Science Volume: 368 Issue: 6488 Pages: 281-281
  • DOI: 10.1126/science.aay6912
  • Peer Reviewed / Int'l Joint Research
• [Presentation] The ribosome collision sensor Hel2 functions as preventive quality control in the secretory pathway (2021)
  • Author(s): Yoshitaka Matsuo, Toshifumi Inada
  • Organizer: 第22回日本RNA学会年会
• [Presentation] 異常翻訳を標識するリボソームユビキチンコードの作動機構 (2021)
  • Author(s): 松尾芳隆 稲田利文
  • Organizer: 第94回日本生化学会大会
  • Invited
• [Presentation] Ribosome collision sensor Hel2 recognizes mistargeting secretory ribosome-nascent chain complexes (2021)
  • Author(s): Yoshitaka Matsuo and Toshifumi Inada
  • Organizer: 第15回日本ゲノム微生物学会年会
• [Presentation] RQT 複合体による異常な翻訳停滞の解消機構 (2020)
  • Author(s): 松尾芳隆 、Petr Tesina、Roland Beckmann、稲田利文
  • Organizer: 第53回酵母遺伝学フォーラム報告会
• [Presentation] The Ccr4-Not complex monitors the translating ribosome for codon optimality (2020)
  • Author(s): Yoshitaka Matsuo, Robert Buschauer, Takato Sugiyama, Jeff Coller, Roland Beckmann, Toshifumi Inada.
  • Organizer: 第43回日本分子生物学会年会
• [Presentation] RQT complex dissociates ribosomes collided on endogenous RQC substrate (2019)
  • Author(s): 松尾芳隆
  • Organizer: 第21回日本RNA学会年会
• [Remarks] タンパク質の配送異常を排除するしくみ ～翻訳に共役した品質管理機構の新たな機能を解明～
  • URL: https://www.tohoku.ac.jp/japanese/2021/03/press20210324-02-protein.html