Cloning and characterization of an ascidian homolog of the human 8-oxoguanine DNA glycosylase (Ogg1) that is involved in the repair of 8-oxo-7,8-dihydroguanine in DNA in Ciona intestinalis
Cloning and characterization of an ascidian homolog of the human 8-oxoguanine DNA glycosylase (Ogg1) that is involved in the repair of 8-oxo-7,8-dihydroguanine in DNA in Ciona intestinalis
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DOI：
10.1080/09553000600649216
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发表时间：
2006-04-01
影响因子：
2.6
通讯作者：
Yonei, S.
中科院分区：
文献类型：
--
作者：
Jin, G.;Zhang, Q. -M.;Yonei, S.
目的：对DNA糖基酶的保守结构域和DNA碱基切除修复系统的进化进行系统的比较分析。此外，研究碱基切除修复在生物发育过程中的作用和调控也很重要。为了解决这些问题，我们首先确定了8-oxo-7,8-二氢鸟嘌呤(8-oxoG)-DNA糖基化酶（Ogg1）作为一个很好的模型系统。材料和方法：从Ciona cDNA资源的EST数据库中鉴定出一个与人类Ogg1同源的cDNA克隆。我们检测了CiOgg1是否具有DNA糖基酶/AP（无嘌呤/无嘧啶）裂解酶对含8- oxog寡核苷酸的活性。进一步比较了CiOgg1在鸡肠各组织中的表达水平。结果：该基因编码一个351个氨基酸的蛋白，与人类Ogg1的氨基酸序列同源性为37%。Helix-hairpin-Helix基序高度保守。海鞘酶具有功能性的8-oxoG-DNA糖基酶/AP裂解酶活性，可从DNA中去除8-oxoG对胞嘧啶。表达CiOgg1显著降低了大肠杆菌中自发G:C转化为T:A的频率。在鸡睾丸中表达量最高。结论：Ogg1的结构和功能在鸡肠中保存较好。CiOgg1参与肠草DNA中8-oxoG的修复。
Purpose: It is of interest to perform a systematic comparative analysis of the conserved domains in DNA glycosylases and the evolution of DNA base excision repair systems. Furthermore, it is important to characterize the roles and regulation of base excision repair during the development of organisms. To address these issues, we first identified 8-oxo-7,8-dihydroguanine (8-oxoG)-DNA glycosylase (Ogg1) of the ascidian Ciona intestinalis as a good model system.Materials and methods: A cDNA clone coding for a peptide with homology to human Ogg1 was identified in the expressed sequence tag (EST) database from the Ciona cDNA resources. We examined whether CiOgg1 has DNA glycosylase/AP (apurinic/apyrimidinic) lyase activities for 8-oxoG-containing oligonucleotide. Furthermore, the expression level of CiOgg1 was compared in various tissues of Ciona intestinalis.Results: The CiOgg1gene encoded a protein of 351 amino acids, which shows 37% identity of amino acid sequence with human Ogg1. The Helix-hairpin-Helix motif was highly conserved. The ascidian enzyme had functional 8-oxoG-DNA glycosylase/AP lyase activities, which removed 8-oxoG opposite cytosine from DNA. Expression of the CiOgg1 significantly reduced the frequency of spontaneous G:C to T:A transversions in E. coli mutM mutY. The highest expression level was observed in testis in Ciona intestinalis.Conclusions: The structure and functions of Ogg1 are well conserved in Ciona intestinalis. CiOgg1 is involved in the repair of 8-oxoG in DNA in Ciona intestinalis.