細胞周期調節されたDNA二重鎖の断裂は,免疫グロブリン遺伝子の体的ハイパーミューテーションで起こります
1Section of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06520-8011, USA.
Nature
|November 23, 2000
まとめ
B細胞における体性高変異は,免疫応答中にDNAの二重鎖断裂 (DSB) を引き起こします. 転写と細胞サイクルに関連したこれらのDSBは,同種の再結合によって修復され,突然変異を導入することができます.
科学分野:
- 免疫学 免疫学とは
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- B細胞は,免疫応答中に免疫グロブリン変異領域遺伝子の標的型ハイパーミューテーションを経験します.
- ソマティック・ハイパーミューテーションは,特定のDNAホットスポットで点変異を生成し,抗体親和性の成熟に決定的な役割を果たします.
- このプロセスは転写に関連しており,免疫グロブリン強化剤を必要とします.
研究 の 目的:
- ソマティック・ハイパーミューテーションの基礎となる分子機構を調査する.
- DNAの二重鎖断裂 (DSB) がソマティックハイパーミューテーションに関与しているかどうかを判断する.
- ソマティック・ハイパーミューテーション中に突然変異の導入モデルを提案する.
主な方法:
- B細胞内のハイパーミュータント配列におけるDNA二重鎖断裂 (DSB) の分析.
- DSB生成と転写,増強剤活性,細胞サイクル進行との相関.
- DSBと突然変異の出現の関係に関する調査.
主要な成果:
- 過剰なDNA二重鎖断裂 (DSB) は,超変異性免疫グロブリン変異領域配列で検出されました.
- DSBの生成は,転写と結合され,強化剤に依存し,細胞サイクルが制限されていることが判明しました.
- DSBの発生は,近くの変異の出現と相関していた.
結論:
- 同型再結合によるDSBの修復中に突然変異が導入されるモデルが提案されています.
- この発見は,DSBが体内のハイパーミューテーションプロセスにおいて重要な役割を果たすことを示唆している.
- ソマティックハイパーミューテーション中のDSBの存在は,B細胞腫瘍における染色体転位を説明する可能性がある.
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