まとめ
グルココルチコイドは,マウス乳腺腫瘍ウイルス (MTV) の遺伝子転写を調節する. この研究は,感染したラットの肝臓腫細胞におけるホルモン反応要素がウイルスDNAの中にあり,細胞配列を横切っているのではないことを示しています.
科学分野:
- 分子生物学は分子生物学である.
- ウイルス学 ウイルス学 ウイルス学
- 遺伝学 遺伝学とは
背景:
- グルココルチコイドは,ネズミの肝腫組織培養 (HTC) 細胞における統合されたマウリン乳腺腫瘍ウイルス (MTV) 遺伝子の転写を調節することが知られている.
- このホルモン制御を媒介する規制要素の正確な位置は,付近の細胞DNAか,ウイルスゲノム内にあるかは不明のままである.
研究 の 目的:
- MTV遺伝子転写のホルモン調節が,付近の細胞配列から,またはウイルスのDNA内から発生するかどうかを調査する.
- グルココルチコイド媒介によるMTV遺伝子発現における宿主統合部位の役割を決定する.
主な方法:
- MTVと隣接するHTC配列の相対的な転写速度を,MTVに感染した2つのHTC細胞系 (J2.15とJ2.17) で分析した.
- 感染していないHTC細胞の転写速度の測定は,MTVDNAが欠けている同等の配列を用いて行われました.
- MTV遺伝子転写率を定量化するためのRNAパルスラベリング実験.
- 核MTVRNAの5'末端を決定するトランスクリプトマッピング.
主要な成果:
- グルココルチコイドは,J2.17細胞ではMTV遺伝子転写を刺激しますが,J2.15細胞ではそうではありません.
- 付近の細胞配列からの転写は,感染した細胞でも,感染していない細胞でも検出されなかった.
- J2.17細胞におけるMTVRNA合成は,細胞プロモーターからの読み込み転写によるものではない.
- トランスクリプトマッピングにより,MTV RNAの5'端がプロウイルスDNA内にあることが明らかになりました.
結論:
- MTV統合のホストサイトは,ウイルスの遺伝子発現に対して,転写的に活性またはホルモンに反応する必要はありません.
- グルココルチコイド誘発のMTVRNA合成は,プロウイルスDNA内に位置するホルモン反応性要素によって媒介され,細胞配列を横切らない.
- これらの発見は,統合されたマウイン乳腺腫瘍ウイルスが,グルココルチコイド反応に対する独自の規制要素を含んでいることを示しています.
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