放射線によって引き起こされる細胞サイクル停止は,p21欠乏によって損なわれます
J Brugarolas1, C Chandrasekaran, J I Gordon
1Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge 02139, USA.
Nature
|October 12, 1995
まとめ
細胞サイクル阻害体であるタンパク質p21は,腸内細胞の分化やDNA損傷によるアポトーシスに影響を与えない. しかし,p21欠乏は,DNA損傷後のマウスの線維芽細胞におけるG1細胞サイクル停止を損なう.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- 遺伝学 遺伝学とは
背景:
- タンパク質p21は,サイクリン依存キナーゼと増殖細胞核抗原 (PCNA) の二重阻害剤として作用し,細胞サイクル進行に不可欠です.
- p21遺伝子はp53によって調節され,p53-依存の細胞サイクル停止とアポトーシスの役割を示唆しています.
- また,p21は,終末分化時に細胞衰老と細胞サイクル停止に関連しています.
研究 の 目的:
- 細胞周期調節,分化,アポトーシスにおけるp21の役割を調査する.
- 遺伝子組み換えマウスモデルを使用してp21のインビボ機能を決定する.
主な方法:
- p21ノックアウト (p21-/-) 細胞とワイルドタイプ (p21+/+) 細胞の両方で構成されたキメアマウスを使用した.
- 大人の小腸の成分について,免疫ヒストキミカル分析を行った.
- DNA損傷後のp21-/-マウスの胚性線維芽細胞におけるG1停止の評価.
主要な成果:
- p21の削除は,腸の上皮細胞の分化に顕著な影響を及ぼさなかった.
- p21欠乏症は,放射線への反応としてp53-依存アポトーシスに影響しませんでした.
- p21-/- マウス胚線維芽細胞は,DNA損傷後のG1停止の障害を示した.
結論:
- p21は腸内上皮細胞の分化や放射線誘発によるアポトーシスには不可欠ではありません.
- p21は,DNA損傷に対する反応としてG1細胞サイクル停止を促進する上で重要な役割を果たします.
- これらの発見は,細胞サイクル制御と組織ホメオスタシスにおけるp21の特定の機能を明確にします.
関連する概念動画
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