藻類のTET同種によって触媒化されたビタミンC由来DNA変異
Jian-Huang Xue1, Guo-Dong Chen1, Fuhua Hao2
1State Key Laboratory of Molecular Biology, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China.
Nature
|May 3, 2019
まとめ
科学者は,ビタミンCを用いたTETホモログ酵素 (CMD1) によって触媒化された藻類の新しいDNA変異を発見した.この表遺伝子マークは,クロミドモナス・ラインハーディの光合成の調節とストレス反応に影響する.
科学分野:
- エピジェネティクスとDNA変異
- 分子生物学
- 植物学
背景:
- サイトシンメチル化 (5mC) は多くの生物における重要な表遺伝子マーカーである.
- 10−11 転位 (TET) ダイオキシゲンゼは,哺乳類における5mC酸化とDNA脱メチル化を媒介する.
- 他の真核生物,特にDNA塩基改変におけるTET同類の機能はほとんど不明である.
研究 の 目的:
- 緑の藻類である Chlamydomonas reinhardtiiのTET同類の酵素活性と機能を調査する.
- 新規のDNA変異と,真核の表遺伝子調節におけるその役割を特定する.
- DNAの変異とビタミンCと ストレス反応の関係を探るためだ
主な方法:
- TET同種であるクラミドモナスの5mC変異酵素 (CMD1) を特定した.
- Fe (II) とL-アスコルビック酸 (ビタミンC) を共同基質として必要とするCMD1の触媒活性を特徴づけた.
- 遺伝子解析を用いて野生型とCMD1変異株におけるビタミンC由来DNA変異の存在を分析した.
主要な成果:
- CMD1は,グリセリル分子の5mCへの結合を触媒化し,新しいDNA塩基改変を形成する.
- この変異はビタミンCに依存し,グリオキシル酸とCO2の副産物となる.
- CMD1変異細胞は,光保護遺伝子LHCSR3の超メチル化とダウンレギュレーションにより,高光下での適応性が低下しています.
結論:
- ビタミンCを用いた異なるTETホモログ (CMD1) によって触媒化された新しい真核DNA塩基変異を特定した.
- このビタミンC由来の変異は潜在的表遺伝子マーカーとして作用し,DNAメチル化を抑制する可能性があります.
- CMD1媒介のDNA変異は,クロミドモナス・ラインハーディの光合成とストレス耐性を調節する役割を果たします.
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