人間のカルシウムホメオスタシス調節器2の構造とゲートメカニズム
Wooyoung Choi1, Nicolina Clemente1, Weinan Sun2,3
1Van Andel Institute, Grand Rapids, MI, USA.
Nature
|November 29, 2019
まとめ
カルシウムホメオスタシス調節器 (CALHM) はATPの放出と神経機能に関与するイオンチャネルである. この研究は,CALHM2チャンネルを明らかにします.
科学分野:
- 構造生物学
- 分子神経科学
- イオンチャンネル生理学
背景:
- カルシウムホメオスタシス調節器 (CALHM) は,ATPの放出とニューロンのシグナル伝達に関与する重要なイオンチャンネルです.
- CALHMの機能障害は神経学的障害に 関わっている.
- CALHM2の構造を理解することは,その機能と機能不全を明らかにする鍵です.
研究 の 目的:
- 人間のCALHM2チャネルの高解像度構造を決定する.
- ルテニウムレッド (RUR) によるCALHM2チャネル阻害のメカニズムを解明する.
- CALHM2チャネルのアーキテクチャとゲーティングの原理を明らかにする.
主な方法:
- CALHM2の構造を得るために,冷凍電子顕微鏡 (cryo-EM) が使用された.
- 構造は,Ca2+ のない活性状態と,RUR による抑制状態の両方に決定された.
- RUR結合時のチャネルアーキテクチャ,対称性,および構成の変化の分析.
主要な成果:
- 活性状態と抑制状態のヒトCALHM2の高解像度の冷凍EM構造が得られました.
- CALHM2チャネルはアンデカメリックヘミチャネルとギャップ・ジャンクションを形成する.
- ルテニウムレッド結合は,収縮した孔と上昇したS1ヘリックスを含む構造変化を誘導し,抑制状態を安定させます.
結論:
- この研究は,CALHM2チャネルアーキテクチャと対称性に関する詳細な構造の洞察を提供します.
- S1とN端のヘリクスを含む2段のゲートメカニズムが提案されています.
- S1の近くのRUR結合部位は,健康と疾患におけるCALHM2チャネル機能を理解するための基礎を提供するチャネル阻害を説明する.
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