人間のMHC-Iペプチド負荷複合体の構造
Andreas Blees1, Dovile Januliene2, Tommy Hofmann3
1Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Strasse 9, 60438 Frankfurt/Main, Germany.
Nature
|November 7, 2017
まとめ
ペプチド負荷複合体 (PLC) の構造は,免疫反応のためのペプチド輸送とMHC-I負荷の調整を明らかにする. これは適応免疫の発起の 分子基盤を明らかにしています
科学分野:
- 免疫学
- 構造生物学
- 分子細胞生物学
背景:
- ペプチド負荷複合体 (PLC) は,ペプチド-MHC-I複合体をエンドプラズマの網膜に組み込むことで,適応免疫に不可欠です.
- そのダイナミックで異質な性質は,以前は構造的および機械的研究を妨げていた.
研究 の 目的:
- 人間のペプチド負荷複合体 (PLC) の原生構造と分子組織を決定する.
- メジャー・ヒストコンパティビリティ・コンプレックスクラスI (MHC-I) の組立とペプチド負荷のメカニズムを解明する.
主な方法:
- ウイルスの阻害剤を用いて,Burkittのリンパ腫細胞からヒトPLCを分離する.
- 低温電子顕微鏡 (cryo-EM) による本来のPLC構造の決定.
- ダイナミックなプロセスを理解するための異なるアセンブリ状態の分析.
主要な成果:
- 抗原処理 (TAP) に関連するトランスポーター周りの2つの編集モジュール (タパシン,カルレチクリン,ERp57,MHC-I) の擬似対称的な配置を明らかにした.
- MHC-Iの校正とペプチドの編集を容易にするチャプロンネットワークを特定した.
- TAPとMHC-Iへのペプチドチャネリングの転位経路を説明した.
結論:
- この研究では,PLCの分子構造を定義し,MHC-IアセンブリにおけるTAPとチャペロンネットワークの相互作用を明らかにした.
- 適応性免疫反応の開始に不可欠なMHC-Iの徴募,編集,放出に関するメカニズム的な洞察を提供します.
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