ラブゲラニルゲラニルトランスファーゼのコンポーネントAの浄化:コロイドレミア遺伝子産物との同一性の可能性
M C Seabra1, M S Brown, C A Slaughter
1Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas 75235.
Cell
|September 18, 1992
まとめ
ラブゲラニルゲラニルトランスファーゼ (GGトランスファーゼ) は,ゲラニルゲラニルをラブタンパク質に結合させるのに不可欠です. その成分Aは,コロイドレミアに関連したタンパク質との類似性を示し,この網膜変性症候群の潜在的な原因を示唆しています.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 神経科学は神経科学である.
背景:
- ラブゲラニルゲラニルトランスファーゼ (GGトランスファーゼ) は,翻訳後の改変における重要な酵素である.
- AとBという2つの成分から構成され,Bは60kdのポリペプチドと38kdのポリペプチドを含む.
研究 の 目的:
- ネズミの脳GGトランスファーゼのコンポーネントAを精製し,特徴づけること.
- Rab GTP結合タンパク質の改変におけるGGトランスファーゼの役割を調査する.
- GGトランスファーゼとホロイドレミアの間の潜在的な関連性を調査する.
主な方法:
- コンポーネントA (95kdポリペプチド) の浄化.
- Rab3AとRab1Aのゲラニルゲラニル化を研究するための酵素分析.
- Rab1A COOH-末端システインのサイト指向型変異.
- ペプチド配列と,既知のタンパク質との比較.
主要な成果:
- コンポーネントAは,単一の95kdポリペプチドとして精製されました.
- ホロ酵素は,ラブ3Aとラブ1Aのシステインにゲラニルゲラニルを結合させます.
- Rab1AにおけるCOOH末端システインの変異により,反応は廃止され,野生型のRab geranylgeranylationが抑制されました.
- コンポーネントAペプチドは,コロイドレミア遺伝子産物との類似性を示した.
結論:
- コンポーネントAは,保存された配列を介してラブタンパク質に結合する可能性が高い.
- コンポーネントBは,ゲラニルゲラニルの移転を担当しています.
- このGGトランスファーゼ経路の欠陥は,X関連網膜変性であるホロイドレミアを引き起こす可能性があります.
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