プラスティド遺伝子発現の制御:3'逆転リピートはmRNA処理および安定化要素として作用するが,転写を終了させない

D B Stern¹, W Gruissem

¹Department of Botany, University of California, Berkeley 94720.

Cell

|December 24, 1987

まとめ

植物のプラスティドDNAの反転繰り返しの配列はトランスクリプション・ターミネーターではなく,RNA処理要素として作用します. これらの配列はRNAの安定性を高め,遺伝子発現の調節に影響を与えます.

科学分野:

分子生物学は分子生物学である.
植物科学植物科学について
遺伝学遺伝学とは

背景:

高級植物におけるプラスティドDNA転写ユニットには,3'端の反転繰り返しの配列が含まれています.
遺伝子発現におけるこれらの逆転繰り返しの正確な機能は,現在も調査中です.

研究の目的:

高級植物プラスティドDNAトランスクリプションにおける3'エンドの反転繰り返しの配列の役割を調査する.
これらの配列が転写ターミネーターまたはRNA処理要素として機能するかどうかを判断する.

主な方法:

植物プラスティドからの同類のインビトロトランスクリプション抽出物を使用しました.
逆転した繰り返しの配列を含む合成RNA分子.
RNA処理と3'-エンド形成を分析するためにS1核酶保護実験を行った.
動的測定を用いてクロロプラスト抽出物におけるRNAの安定性を評価した.

主要な成果:

逆転の繰り返し配列は,転写ターミネーターとして無効であることが判明しました.
これらの配列は,効率的なRNA処理要素として機能し,核酵素による3'-5'処理を指揮する.
in vitroで生成された3'-端は,ほぼ均質であり,プラスティドmRNAの in vivo で観察されたものと一致しました.
3'エンドの反転繰り返しのRNAは,対照RNAと比較して,安定性が著しく向上した.

結論:

植物性プラスチドの3'端の反転繰り返しは,トランスクリプション・ターミネーターではなく,RNAの処理と安定性の重要な要素である.
これらの特徴は,プラスティド遺伝子発現の転写後の調節に重要な役割を果たしている可能性が高い.
この発見は,植物発達の過程で異なるRNAの蓄積のメカニズムを示唆している.

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