細胞サイクル進行中のDNA複製の起源の規制
K Shirahige1, Y Hori, K Shiraishi
1Nara Institute of Science and Technology, Ikoma, Japan.
Nature
|October 23, 1998
まとめ
rad53タンパク質はDNA複製のタイミングを調節し,DNA損傷に対する反応として遅い起源の開始をブロックします. このチェックポイントタンパク質は,Saccharomyces cerevisiaeのS相進行をモニタリングするために不可欠です.
科学分野:
- 分子生物学は分子生物学である.
- 細胞サイクル規制について
- DNAレプリケーション DNA複製
背景:
- Saccharomyces cerevisiaeの染色体VIは,9つのDNA複製原点があり,開始頻度は異なります.
- これらの起源は,細胞サイクルのS段階の間に連続的に複製されます.
研究 の 目的:
- 複数の起源の活性化とS相進行の調節との関連を調査する.
- DNA損傷 (MMS) とチェックポイント遺伝子変異 (rad53) が起源活動と細胞サイクル進行に及ぼす影響を決定する.
主な方法:
- 2次元のゲル電泳法で,起源の活性度を測定する.
- 細胞サイクル進行を監視するために,光活性化された細胞分類.
- DNA損傷誘導のためにメチルメタン硫酸塩 (MMS) を利用する.
- チェックポイント遺伝子の突然変異,特にrad53.5を使用しています.
主要な成果:
- MMS治療はS相を遅らせ,遅い複製の起源から開始を選択的にブロックします.
- rad53の変異は遅い/非効率な起源を強化し,MMS誘発のイニシアチブブロックを覆す.
- rad53変異により,遅い起源が早く複製される.
- orc2変異は,遅い起源を抑制することにも関わっています.
結論:
- rad53は,正常な細胞成長中の遅い起源開始のタイミングを調節する.
- rad53は監視メカニズムとして機能し,MMSで処理された細胞の遅い起源開始をブロックします.
- rad53はS相進行を監視する役割を果たします.
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In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of replication.
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