ボルトゲート式Na+/H+交換器の構造と電機結合
Hyunku Yeo1, Ved Mehta1, Ashutosh Gulati1
1Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Stockholm, Sweden.
Nature
|October 25, 2023
まとめ
精子伝達器SLC9C1は,電圧感知ドメインによって調節され,精子の運動性を活性化します. Cryo-EM構造は 独特の電圧活性化メカニズムを明らかにし 受精に不可欠です
科学分野:
- 構造生物学
- 分子・細胞生理学
- 生殖生物学
背景:
- 電圧感知ドメイン (VSD) は通常,イオンチャネルを調節しますが,SLC9C1はユニークな例外です.
- 精子特異的なSLC9C1は,精子の運動性と受精に不可欠であり,pHの変化とCatSperチャネル活性化を媒介する.
- SLC9C1の電圧活性化の分子メカニズムは不明のままです.
研究 の 目的:
- 精子Na+/H+交換器SLC9C1における電圧依存活性化の構造的基礎を解明する.
- SLC9C1機能におけるVSDとサイクル核酸結合ドメインの役割を理解する.
主な方法:
- 低温電子顕微鏡 (cryo-EM) で,海SLC9C1の構造を決定する.
- 洗剤とナノディスクのSLC9C1の構造分析,cAMPとcAMPなし
主要な成果:
- 新しい冷凍-EM構造は,SLC9C1ホモダイマーに並ぶ異常なVSD構成を明らかにします.
- 長いS4セグメントは,VSDをサイクル・ヌクレオチド・バインディングドメインに接続し,不活性な"アップ"形状を採用する.
- 細胞内ヘリクスは不活性状態のイオン輸送を制限し,これはハイパーポラライゼーションとcAMP結合時にS4運動によって緩和される.
結論:
- この研究は,SLC9C1における電圧依存のNa+/H+交換の構造的メカニズムを明らかにした.
- cAMPによって調節される超極化誘発S4セグメントの動きは,SLC9C1の活性化の鍵です.
- この研究は精子の機能と受精過程について 重要な洞察力を提供します
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