アスガルドの古生物の微小管
Florian Wollweber1, Jingwei Xu1, Rafael I Ponce-Toledo2
1Department of Biology, Institute of Molecular Biology & Biophysics, Eidgenössische Technische Hochschule Zürich, Otto-Stern-Weg 5, 8093 Zürich, Switzerland.
Cell
|March 22, 2025
まとめ
微小管を形成するチューブリンが,真核生物の最も近い親族であるアスガルドのアルカイアで発見され,これらの重要な細胞構造の真核生物以前の起源を示唆している. これらのアーカイアル・チューブリンが ユカリオットのような微小管に組み合わさります
科学分野:
- 細胞生物学
- 進化生物学
- 生物化学
背景:
- 微小管は,α/β-チューブリン異極体によって形成される重要な真核構造である.
- 古代生物やバクテリアのチューブリンホモログは通常,管状でない構造を形成する.
- 微小管の組成の進化的起源はほとんど不明である.
研究 の 目的:
- 微小管を形成するチューリンの起源を調査する.
- ユカリオットの最も近い親類であるアスガルドの古生物のチューブリンホモログを特徴づける.
- 考古学的なチューブリンの組み立てメカニズムを解明する.
主な方法:
- Candidatus Lokiarchaeum ossiferumのプロテオミクス分析について
- 構造を決定するための冷凍電子顕微鏡 (Cryo-EM).
- In vitroポリメリゼーションアッセイ
- 細胞視覚化のための冷凍トモグラフィーと膨張顕微鏡
主要な成果:
- アスガルド古生物でアスガルドチューブリン (AtubA/B) が発見され,真核チューブリンと密接に関連している.
- AtubA/Bは,eukaryoteのようなヘテロダイマーを形成し,in vitroで5原生糸微小管に組み合わされます.
- パラログであるAtubB2は,核酸結合部位を欠き,AtubA/Bと共に7原糸非正規微小管を形成する.
- In situでは,AtubA/BはCa内の細胞骨格組成と管状構造を形成する. ロキアーキウム・オシフェラムの細胞
結論:
- 微小管の形成は,アルカイア系に由来するエウカリウトの出現に先行する.
- アスガルドの古生物は機能的な微小管を形成するチューブリンを持ち,その組立特性が保たれている.
- この発見は 微小管の進化と組み立ての 基本的な原理の洞察を与えてくれます
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