哺乳類のテロメアは,大きな二重ループで終わる

J D Griffith¹, L Comeau, S Rosenfield

¹Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill and Curriculum in Genetics and Molecular Biology, 27599-7295, USA. jdg@med.unc.edu

Cell

|May 25, 1999

まとめ

テロメア保護タンパク質TRF2は,テロメアDNAを大きな二重ループ (tループ) に再構成する. 人間とマウスの細胞で見られるこれらのtループは,染色体の末端を保護し複製する可能性があります.

科学分野:

細胞生物学細胞生物学
分子生物学は分子生物学である.
遺伝学遺伝学とは

背景:

哺乳類のテロメアは,TRF1およびTRF2.2を含むタンパク質に結合した繰り返しDNA配列で構成されています.
TRF2はテロメア末端の保護に不可欠であり,その抑制は染色体末端の脱保護と融合につながる.

研究の目的:

テロメア維持におけるTRF2の構造的役割を調査する.
テロメア末端保護のメカニズムを解明する.

主な方法:

電子顕微鏡を用いたインビトロ生化学測定法で,DNAの構造変化を観察する.
電子顕微鏡を用いたヒトとマウスの細胞からのプソラレンのクロスリンクテロメリックDNAの分析.

主要な成果:

TRF2は線形テロメアDNAを in vitro で大きな二重ループ (tループ) に再構成することが示されました.
人とマウスの細胞からのテロメアDNAに豊富なtループが特定されました.
証拠によると,tループは,TRF1および単一鎖結合タンパク質を含む二重テロメア配列への3'オーバーハン侵入によって形成される.

結論:

テロメア再結合因子2 (TRF2) は,テロメアループ (tループ) の形成に重要な役割を果たします.
Tループは哺乳類の細胞に保存された構造であり,テロメアの保護と複製のためのメカニズムとして機能する可能性があります.

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