Molecular and structural basis and modification mechanisms of the active zones regulating synaptic transmission efficiency

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H03324
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 46010:Neuroscience-general-related
• Research Institution: University of Yamanashi
• Principal Investigator: Ohtsuka Toshihisa 山梨大学, 大学院総合研究部, 教授 (40401806)
• Co-Investigator(Kenkyū-buntansha): 萩原 明 東京理科大学, 理工学部応用生物科学科, 准教授 (70402849)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: アクティブゾーン / CAST / ELKS / ビオチンリガーゼ / 液-液相分離

Outline of Final Research Achievements

Using constructs with different linker lengths between the biotin ligase and CAST, we proceeded to analyze their expression and localization in cultured hippocampal neurons and quantified their co-localization with Bassoon, showing a statistically significant difference in the degree of co-localization between the biotin signal and the Bassoon signal depending on the linker length. The results showed a statistically significant difference in the degree, suggesting that different linker lengths can detect different binding molecule complexes depending on the distance from CAST at active zones.
In addition, no cytoplasmic droplet formation was observed when RIM1 was expressed alone, and significant droplet formation could only be observed when coexpressed with CAST/ELKS. These results suggest that liquid-liquid phase separation may play an important function in the formation of active zone complexes.

Free Research Field

神経生化学

Academic Significance and Societal Importance of the Research Achievements

本研究で、アクティブゾーンにおける近位ビオチンラベル化法を確立した。アクティブゾーンタンパク質CAST/ELKSが形成するタンパク質複合体のさらなる解析から、複合体のタンパク質組成が脳内の異なる領域でどのように違っているか、分子レベルでの知見が期待される。分子・シナプスレベルでの違いが、最終的には個体レベルの機能（脳機能や行動）にどのような影響をおよぼすのか、その因果関係の解明につながる学術的な意義を有する。また、アルツハイマー病などの認知症においてもシナプスレベルの変化が知られており、本研究で開発した手法をモデルマウス等に用いることで、認知症研究の発展につながり、社会的な意義も高い。