Intracellular localization and function of DNA repair methyltransferase in human cells

Toru Ishibashi, Yusaku Nakabeppu, Hisaya Kawate, Kunihiko Sakumi, Hiroshi Hayakawa, Mutsuo Sekiguchi

研究成果: ジャーナルへの寄稿学術誌査読

38 被引用数 (Scopus)


An antibody preparation specific for human O6-methylguanine-DNA methyltransferase (EC was obtained by immunoaffinity purification on two types of affinity columns with the purified human and mouse methyltransferase proteins as ligands. The antibodies were used in Western blotting analysis of fractionated cell extracts. More than 90% of the methyltransferase protein was recovered in the cytoplasmic fractions with both human HeLa S3 cells and MR-M cells, the latter overproducing the enzyme 36 time as much as the former. Cytoplasmic localization of the methyltransferase in HeLa S3 cells was further confirmed by in situ immunostaining. By Western blotting analysis of fractionated cell extracts from HeLa S3 cells treated with alkylating agents, we found that amounts of the enzyme decreased more rapidly in the nuclear fraction than in the cytoplasmic fraction, and recovery of the enzyme level in the cytoplasmic fraction was slower than that in the other. These results suggest that the methyltransferase protein is degraded in the nucleus after it commits the repair reaction and that the cytoplasmic enzyme is transported into the nucleus as the nuclear methyltransferase is used up in this manner.

ジャーナルMutation Research-DNA Repair
出版ステータス出版済み - 11月 1994

!!!All Science Journal Classification (ASJC) codes

  • 分子生物学
  • 毒物学
  • 遺伝学


「Intracellular localization and function of DNA repair methyltransferase in human cells」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。