Arf1に依存したコアトーマーを膜に誘導する構造に基づくメカニズム

Xinchao Yu¹, Marianna Breitman, Jonathan Goldberg

¹Howard Hughes Medical Institute and the Structural Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.

Cell

|February 7, 2012

まとめ

COPIでコーティングされた膀の芽生えには,Arf GTPaseとコアトーマーが必要です. 研究者はArf1がコアトーマーに結合する構造を明らかにし,膀形成に不可欠な二価結合モードを明らかにした.

科学分野:

細胞生物学細胞生物学
分子生物学は分子生物学である.
構造生物学構造生物学とは

背景:

膀輸送は細胞組織にとって不可欠であり,COPIやクラトリンアダプタのようなタンパク質コートを含む.
Arf GTPasesとコアトーマー複合体は,ゴルギとエンドソーム膜から膀の芽生えを媒介する.
Arf-GTPの膜への採用の構造的基礎を理解することは,コートアセンブリを解読する上で鍵となる.

研究の目的:

Arfに依存した膜へのコート採用の構造的基礎を決定する.
Arf1-GTPとコアトーマー複合体の相互作用を調査する.

主な方法:

X線結晶学で, γζ-COPサブコンプレックスに結合したArf1の構造を決定する.
Arf1-コアトーマー相互作用を特徴付けるための構造主導の生化学分析.

主要な成果:

結晶構造は,Arf1が γζ-COPサブコンプレックスに結合していることを明らかにしました.
生物化学分析により,βδ-COPの2番目のArf1-GTP結合部位が特定されました.
コアトーマー上のArf1結合部位は,AP2上のPtdIns4,5P(2)結合部位と空間的関係を共有しており,膜結合の方向性が保存されていることを示唆しています.

結論:

Arf1がコアトーマーに結合する双価でGTPに依存する結合モードが明らかになった.
この結合モードは,ゴルギのコアトーマー動態と貨物の選択に影響を与える.
この発見は,ベジキュラーコートタンパク質の膜徴募の一般的なメカニズムについての洞察を提供します.

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