Elucidation of the formation and destruction mechanism of liquid-liquid phase separation in SMC using a high-speed AFM/optical tweezers combination device

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04849
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 28040:Nanobioscience-related
• Research Institution: Kanazawa University
• Principal Investigator: Umeda Kenichi 金沢大学, ナノ生命科学研究所, 特任助教 (60746915)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 高速AFM / 染色体維持構造タンパク質 / DNA / 生体機能動態

Outline of Final Research Achievements

To elucidate the mechanism of chromosome formation in SMC, I used high-speed AFM to visualize the functional dynamics of SMC at the submolecular scale. First, I performed observation on mica, which is commonly used for AFM observation, and succeeded in obtaining clear molecular images. By performing coarse-grained simulations, I succeeded in identifying the O-form molecular structure. Furthermore, by optimizing the lipid membrane experimental system, I succeeded in imaging SMC bound to DNA at submolecular resolution. I also succeeded in visualizing the clear molecular structure of the head and hinge binding mode that appear in the ATPase hydrolysis reaction, and succeeded in obtaining direct evidence for the pictures that has been conventionally obtained in biochemical experiments.

Free Research Field

生物物理学

Academic Significance and Societal Importance of the Research Achievements

SMCのサブ分子分解能での機能動態の可視化に成功したことで、これまで生化学実験結果に基づいて描いていたイラストをダイレクトに実証することができた。更に、これまで高速AFM観察において、マイカ基板が広く用いられており、SMCなど生きた状態にある生体分子を計測できないケースが多かった。本研究において、脂質膜を用いた高速AFMイメージングの確立に成功し、これまで生体機能動態の可視化が難しかった他の生体分子にも応用可能であることを示すことができた。