Study of cellular responses to single-strand break

细胞对单链断裂反应的研究

基本信息

批准号：
10480131
负责人：
YASUI Akira
金额：
$ 7.55万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10480131/
关键词：
DNA damage DNA repair DNA break circadian rhythm photo repair excision repair 塩基損傷 DNA単鎖切断 PARP XRCC1 塩基除去修復単鎖切断紫外線損傷

项目摘要

Although single-strand breaks (SSBs) occur frequently, the cellular responses and repair of SSB are not well understood. To address this, we established mammalian cell lines expressing Neurospora crassa UV damage endonuclease (UVDE), which introduces a SSB with a 3'-OH, immediately 5' to UV-induced cycrobutane, pyrimidine dimers or 6-4 photoproducts and initiates an alternative excision repair process. Xeroderma pigmentosum group A cells expressing UVDE show UV resistance of almost the wild-type level. In these cells SSBs are produced upon UV irradiation and then efficiently repaired. The repair patch size is about 7 nucleotides and repair synthesis is decreased to 30% by aphidicoline, suggesting the involvement of a DNA polymerase δ/ε-dependent long-patch repair. Immediately after UV irradiation cellular proteins are poly(ADP-ribosyl)ated. The UV resistance of the cells is decreased in the presence of 3-aminobenzamide (3AB), an inhibitor of poly- (ADP-ribose) polymerase (PARP). Expression of UVDE in XRCC1-defective EM9, a Chinese hamster ovary cell line, greatly sensitizes the host cells to UV and addition of 3AB results in almost no further sensitization of the cells to UV. Thus, we show that XRCC1 and PARP are involved in the same pathway for the repair of SSBs.

尽管单链断裂 (SSB) 经常发生，但 SSB 的细胞反应和修复尚不清楚。为了解决这个问题，我们建立了表达粗糙脉孢菌紫外线损伤核酸内切酶 (UVDE) 的哺乳动物细胞系，该细胞系引入了具有 3' 的 SSB。 -OH，立即位于紫外线诱导的环丁烷、嘧啶二聚体或 6-4 光产物的 5' 处，并启动替代切除修复过程。表达UVDE的细胞表现出几乎与野生型水平相同的抗紫外线能力，在紫外线照射下产生SSB，然后有效修复修复斑块大小约为7个核苷酸，并且阿菲迪考林的修复合成减少至30%。 DNA 聚合酶 δ/ε 依赖性长补丁修复在紫外线照射后，细胞蛋白质立即被聚（ADP-核糖基）化。存在时，细胞的紫外线抵抗力会降低。 3-氨基苯甲酰胺 (3AB) 是一种聚 (ADP-核糖) 聚合酶 (PARP) 抑制剂，在 XRCC1 缺陷型 EM9（一种中国仓鼠卵巢细胞系）中表达 UVDE，可极大地提高宿主细胞对紫外线和 3AB 的敏感性。导致细胞几乎不再对紫外线敏感。因此，我们表明 XRCC1 和 PARP 参与修复的相同途径。 SSB。