人間のアミノアシル-tRNA合成酵素から放出される2つの異なるサイトカイン
1The Skaggs Institute for Chemical Biology, The Scripps Research Institute, Beckman Center, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Science (New York, N.Y.)
|April 2, 1999
まとめ
ヒトのチロシル-tRNA合成酵素は,2つのサイトカイン活性断片に分裂する. これらの断片は,アポトーシスで生成され,強力な白血球および単細胞活性化機能を発揮し,細胞プロセスに影響を与えます.
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.
- 免疫学 免疫学とは
背景:
- アミノアシル-tRNA合成酵素は,タンパク質合成に不可欠な酵素であり,アミノ酸の結合を同種の転送RNA (tRNA) に触媒として作用する.
- 新興の証拠は,これらの酵素の触媒的役割を超えた非正規の機能を示唆しています.
研究 の 目的:
- ヒトのチロシル-tRNA合成酵素の潜在的サイトカインのような活動を調査する.
- タイロシル-tRNA合成酵素の異なる断片の機能的性質を決定する.
主な方法:
- 人間のチロシル-tRNA合成酵素の生化学的断片化.
- 白血球と単細胞の化学反応の測定.
- ミエロペロキシダース,腫瘍死滅因子-アルファ,および組織因子生産の測定.
- インタールイキン-8型A受容体への結合の分析.
- 細胞培養実験は,アポプトティックな条件下で行われます.
主要な成果:
- ヒトのチロシル-tRNA合成酵素は,異なるサイトカイン活性を持つ2つの断片に分割することができます.
- カーボキシ末端ドメインは,白血球と単細胞の化学作用を促進し,炎症媒介者の生成を刺激し,内皮単細胞活性化ポリペプチドIIのような活性を示します.
- アミノ端末ドメインは,インタールイキン-8型A受容体と結合し,インタールイキン-8型サイトカインとして機能します.
- アポプトシス状態では,全長酵素が分泌され,白血球エラスタゼによってこれらの活性サイトカインの断片に分割されます.
結論:
- ヒトのチロシル-tRNA合成酵素は,その異なるドメインによって媒介される二重のサイトカイン活性を持っています.
- アポプトシス中のチロシル-tRNA合成酵素の分泌と断片化は,翻訳を停止し,炎症性サイトカインを生成することによって,アポプトシスプロセスに寄与する可能性があります.
関連する概念動画
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02:36Transfer RNA Synthesis
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
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