XPV (xeroderma pigmentosum変種) 遺伝子は,ヒトDNAポリメラーゼエタをコードする
C Masutani1, R Kusumoto, A Yamada
1Institute for Molecular and Cellular Biology, Osaka University, Suita, Japan.
Nature
|June 29, 1999
まとめ
Xeroderma pigmentosum変種 (XP-V) は,紫外線損傷後の欠陥DNA複製に関連しています. 研究者らは,DNAポリメラーゼエタを原因と特定し,XP-V細胞のこの欠陥を修正した.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
- 皮膚科 皮膚科について
背景:
- Xeroderma pigmentosum変種 (XP-V) は,太陽光誘発の皮膚がんリスクを増加させる遺伝疾患です.
- XP-V細胞は正常なDNA修復をしていますが,UVで損傷したDNAの複製には欠陥があります.
- XPV遺伝子のトランスレションDNA合成における役割は疑われていたが,その産物は孤立していない.
研究 の 目的:
- XP-V細胞におけるトランスレシオンDNA合成に責任を負うタンパク質を特定する.
- 紫外線で損傷したDNAの複製におけるDNAポリメラーゼエタの役割を調査する.
- DNAポリメラーゼエタがXPV遺伝子産物であるかどうかを判断する.
主な方法:
- トランス傷害DNA合成のための改良された細胞フリーアッセイを用いた.
- HeLa細胞からXP-V抽出物におけるチミンジマーをバイパスできるDNAポリメラーゼを分離した.
- XP-V細胞のDNAポリメラーゼエタ遺伝子を配列化し,再結合タンパク質の機能をテストしました.
主要な成果:
- 紫外線で損傷したDNAをバイパスして複製するDNAポリメラーゼが分離されました.
- このポリメラーゼはヒトDNAポリメラーゼエタとして識別され,酵母Rad30の同型である.
- テストされたすべてのXP-V細胞は,DNAポリメラーゼエタ遺伝子の変異を含んでいた.
- 再結合ヒトDNAポリメラーゼエタは,XP-V細胞抽出物におけるDNA複製を回復した.
結論:
- DNAポリメラーゼエタは,XPV遺伝子の産物である可能性が高い.
- DNAポリメラーゼエタの欠陥がXP-Vの複製欠陥を引き起こす.
- この発見は,Xeroderma pigmentosumの変種の分子基盤を明確にしています.
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