A possible mechanism of mutagenesis : oxidative stress and nuclear translocation of superoxide dismutase.

诱变的可能机制：氧化应激和超氧化物歧化酶的核转位。

• 批准号: 14570310
• 负责人: OOKAWARA Tomomi
• 金额: $ 2.3万
• 依托单位: Hyogo College of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570310/
• 关键词: reactive oxygen species; superoixde dismutase; extracellular superoxide dismutase; 3T3-LI cell; nuclear localization signal; DNA damae; mutation

Extracellular superoxide dismutase(EC-SOD) is the only known secretory SOD isoenzyme. EC-SOD has a positively-charged heparin-binding domain at the C-terminus and it has been thought that this domain could allow the enzyme characteristic distribution in tissues after the secretion.Histochemical examination of mouse tissues showed nuclear staining of extracellular superoxide dismutase(EC-SOD),and the nuclear translocation of EC-SOD was also confirmed in cultured cells that had been transfected with its gene, as shown by immunohistochemistry and Western blot analysis. The EC-SOD which was secreted into the medium was incorporated into 3T3-LI cells and a significant fraction of the material taken up was localized in the nucleus. Site-directed mutagenesis indicated that the heparin-binding domain of EC-SOD functions as the nuclear localization signal. These results suggest that the mechanism of the nuclear transport of EC-SOD involves a series of N-terminal signal peptide-and C-terminal he … More parin-binding domain-dependent processes of secretion, re-uptake and the subsequent nuclear translocation. The findings herein provide support for the view that the role of EC-SOD is to protect of genome DNA from damage by reactive oxygen species and/or the transcriptional regulation of redox-sensitive gene expression. Moreover, the effect of oxidative stress on the cellular uptake and nuclear translocation of EC-SOD was investigated. Treatment of the 3T3-LI cells with H_2O_2,(5mM for 5min) followed by incubation with CHO-EK medium downregulated the uptake of EC-SOD. Nuclear translocation of the incorporated EC-SOD was clearly enhanced by H_2O_2 treatment following incubation with the CHO-EK medium. EC-SOD is the only anti-oxidant enzyme which is known at this time to be actively transported into nuclei. The results suggest that the upregulation of the nuclear translocation of EC-SOD by oxidative stress might play a role in the mechanism by which the nucleus is protected against oxidative damage of genomic DNA. Less

胞外超氧化物歧化酶（EC-SOD）是目前已知的唯一分泌型SOD同工酶。EC-SOD在C端有一个带正电荷的肝素结合结构域，人们认为该结构域可以使酶分泌后在组织中分布。小鼠组织的组织化学检查显示细胞外超氧化物歧化酶（EC-SOD）的核染色，并且在转染其基因的培养细胞中也证实了EC-SOD的核转位，免疫组化和Western印迹分析显示。分泌到培养基中的EC-SOD被掺入3 T3-LI细胞中，并且所摄取的物质的显著部分定位于细胞核中。定点突变表明，EC-SOD的肝素结合结构域作为核定位信号。上述结果提示，EC-SOD的核转运机制涉及一系列N端信号肽和C端信号肽。 ...更多信息 parin结合结构域依赖的分泌、再摄取和随后的核转位过程。本文的研究结果为EC-SOD的作用是保护基因组DNA免受活性氧和/或氧化还原敏感基因表达的转录调节的损伤的观点提供了支持。此外，还研究了氧化应激对EC-SOD细胞摄取和核转位的影响。用5 mM H_2O_2处理3 T3-LI细胞5 min，再用CHO-EK培养基孵育，可使EC-SOD的摄取量下降。在CHO-EK培养基中孵育后，H_2O_2处理明显促进了EC-SOD的核转位。EC-SOD是目前已知的唯一能主动转运到细胞核中的抗氧化酶。结果表明，上调的EC-SOD的核转位的氧化应激可能发挥作用的机制，其中细胞核是保护免受基因组DNA的氧化损伤。少

项目成果

Ookawara, T.: "Transcription regulation of gene expression in human skeletal muscle in response to endurance training"Res.Commun.Mol.Pathol.Pharmacol.. 111. 41-54 (2002)

Ookawara, T.：“响应耐力训练的人类骨骼肌基因表达的转录调节”Res.Commun.Mol.Pathol.Pharmacol.. 111. 41-54 (2002)

Ookawara, T., et al.: "Nuclear translocation of extracellular superoxide dismutase(EC-SOD)."Biochem.Biophys.Res.Commun.. 296. 56-61 (2002)

Ookawara, T., et al.：“细胞外超氧化物歧化酶 (EC-SOD) 的核易位。”Biochem.Biophys.Res.Commun.. 296. 56-61 (2002)

Ookawara T. et al.: "Nuclear translocation of extracellular superoxide dismutase (EC-SOD)"Biochem Biophys Res Commun. 296・1. 54-61 (2002)

Ookawara T.等：“细胞外超氧化物歧化酶(EC-SOD)的核易位”Biochem Biophys Res Commun.296·1(2002)。

Ookawara T. et al.: "Effects of oxidative stress on the nuclear translocation of extracellular superoxide dismutase"Biochem Biophys Res Commun. 303・3. 914-919 (2003)

Ookawara T.等：“氧化应激对细胞外超氧化物歧化酶核转位的影响”Biochem Biophys Res Commun. 914-919 (2003)。

Ookawara, T., et al.: "Transcription regulation of gene expression in human skeletal muscle in response to endurance training."Res.Commun.Mol.Pathol.Pharmacol.. 111. 41-54 (2002)

Ookawara, T., 等人：“人类骨骼肌基因表达的转录调控响应耐力训练。”Res.Commun.Mol.Pathol.Pharmacol.. 111. 41-54 (2002)