Involvement of nuclear transcription factor in RISC formation in RNA interference

• Project/Area Number: 16H04740
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Molecular biology
• Research Institution: University of Tsukuba
• Principal Investigator: Liu Qinghua 筑波大学, 国際統合睡眠医科学研究機構, 教授 (90723792)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000); Fiscal Year 2018: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2017: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000); Fiscal Year 2016: ¥7,150,000 (Direct Cost: ¥5,500,000、Indirect Cost: ¥1,650,000)
• Keywords: RISC / RNAi / Cryo-EM / miRNA / siRNA / 核酸 / RNA / 核 酸

Outline of Final Research Achievements

Recent technical advances in single particle cryo-EM data acquisition, classification, and reconstruction have caused the “EM resolution revolution” within the last few years. Thus, we have tried to reconstruct the three dimensional structures of the Drosophila RLC complex using cryo-EM. To date, we have obtained low resolution EM structure of Dicer-2-R2D2, Dicer-2-R2D2 complex with siRNA, and Dicer-2-R2D2 and TAF11 in complex with siRNA (RLC). Comparison of the EM maps reveals that Dicer-2-R2D2 complex exists in monomeric and dimeric states. The conformation of the RLC is clearly different from that of Dicer-2-R2D2-siRNA complex, suggesting that TAF11 binding results in significant conformational changes of the RLC, which may be critical for the RISC loading activity.

Academic Significance and Societal Importance of the Research Achievements

RNAi（RNA干渉）は遺伝子の発現制御機構のひとつであり、生命現象において非常に重要な役割を担っている。RISCはRNAiにおいて中核的役割を果たすが、RISC形成の作用機序や活性制御の仕組みは未だ不明な点を多く残す。単粒子解析クライオ電子顕微鏡は、原子分解能で構造を解明するために使用する手法である。2017年には、クライオ電子顕微鏡の開発に貢献した研究者がノーベル化学賞を受賞した。我々はこの最先端技術である単粒子解析クライオ電子顕微鏡を用いて、RISC形成において重要な役割を果たす複合体の構造解析を試みた。その結果、不完全ではあるが、RISC形成に関わる複合体の構造解析に成功した。

Research Products

• [Journal Article] HP1BP3, a chromatin retention factor for co-transcriptional microRNA processing (2016)
  • Author(s): H. Liu#, C. Liang#, R.K. Kollipara, M. Matsui, X. Ke, B-C. Jeong, Z. Wang, K.S. Yoo, G.P. Yadav, L.N. Kinch, N.V. Grishin, Y. Nam, D.R. Corey, R. Kittler, Q.Liu.
  • Journal Title: Mol Cell Volume: 63 Pages: 420-432
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] Cumulative phosphorylation of SNIPPs as a function of homeostatic sleep need (2018)
  • Author(s): Liu Qinghua
  • Organizer: Gordon Research Conference on Sleep Regulation and Function, Galveston, USA
  • Int'l Joint Research
• [Presentation] Quantitative phosphoproteomic analysis of the molecular substrates of sleep need (2018)
  • Author(s): Liu Qinghua
  • Organizer: Texas Society for Circadian Biology and Medicine meeting
• [Presentation] A molecular link between synaptic phosphoproteome and homeostatic sleep need (2017)
  • Author(s): Liu Qinghua
  • Organizer: Cold Spring Harbor Asia meeting Francis Crick Frontier in Neuroscience, Suzhou, China
  • Int'l Joint Research
• [Presentation] Synaptic phosphoproteome as a molecular correlate of sleep need (2017)
  • Author(s): Liu Qinghua
  • Organizer: Asian Chronobiology Forum and 2nd Biennial conference of Chinese Society of Biological Rhythms, Hohhot, China
  • Int'l Joint Research
• [Presentation] A synaptic phosphoproteomic link to homeostatic sleep need (2017)
  • Author(s): Liu Qinghua
  • Organizer: 40th Annual meeting of the Japan Neuroscience Society, Chiba, Japan
• [Presentation] HP1BP3, a chromatin retention factor for co-transcriptional microRNA processing (2016)
  • Author(s): Qinghua Liu
  • Organizer: International RNA society meeting in Kyoto
  • Place of Presentation: Kyoto international conference center (kyoto city)
  • Year and Date: 2016-06-28
  • Invited