イーストミトコンドリア輸入受容体の遺伝子の分離と特徴づけ
1Howard Hughes Medical Institute, Rockefeller University, New York, New York 10021.
Nature
|October 4, 1990
まとめ
MIR1遺伝子は,酵母細胞が非発酵可能な炭素源で成長するのに不可欠なミトコンドリア輸入受容体をコードする. その破壊はミトコンドリアタンパク質の輸入に影響し,複数の輸入経路が存在することを示唆しています.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
背景:
- Saccharomyces cerevisiaeの統合膜タンパク質 (p32) は,以前,ミトコンドリアタンパク質輸入受容体として特定されていました.
- このタンパク質は,接触部位でミトコンドリア外膜に局限していた.
研究 の 目的:
- MIR1.1.と呼ばれるp32タンパク質をコードする遺伝子を分離する.
- ミトコンドリアタンパク質のインポートと細胞機能におけるMIR1タンパク質の機能を調査する.
主な方法:
- MIR1遺伝子の分離と特徴づけ.
- Saccharomyces cerevisiaeのMIR1遺伝子ノックアウト変異体の構築と分析.
- 異なる炭素源での細胞成長の評価.
- ワイルド型およびMIR1障害細胞におけるミトコンドリアタンパク質濃度の分析.
主要な成果:
- MIR1遺伝子は隔離され,その推論されたアミノ酸配列は,ミトコンドリアのリン酸媒介体との同質性を示した.
- 破壊されたMIR1アレルを持つ細胞は,非発酵可能な炭素源では成長障害を示したが,グルコースでは正常な成長を示した.
- MIR1の破壊は,特定のミトコンドリアタンパク質のレベルを低下させ,他のものは影響を受けなかった.
結論:
- MIR1タンパク質は,酵母におけるミトコンドリア機能に不可欠である.
- 結果は,ミトコンドリアにタンパク質を輸入するための複数の経路の存在を示しています.
関連する概念動画
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Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
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Most of the mitochondrial precursors...
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Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
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Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
Protein Transport into the Inner Mitochondrial Membrane
Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
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