Human DDB2 splicing variants are dominant negative inhibitors of UV-damaged DNA repair
Human DDB2 splicing variants are dominant negative inhibitors of UV-damaged DNA repair
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DOI：
10.1016/j.bbrc.2004.01.003
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发表时间：
2004-02-20
影响因子：
3.1
通讯作者：
Endo, H
中科院分区：
文献类型：
--
作者：
Inoki, T;Yamagami, S;Endo, H
受损DNA结合蛋白(DDB)是一种异源二聚体(DDB1和DDB2)，参与紫外线照射后DNA损伤的修复。在这里，我们已经从HeLa细胞(D1-D4)中鉴定出四个DDB2变异体，它们是通过选择性剪接产生的-用RT-PCR对组织分布的分析表明，D1在人脑和心脏中表达最高。DNA修复实验表明，D_1和D_2均为显性负性抑制物。凝胶迁移率改变分析表明，d1和d2不是受损DNA-蛋白质复合体的一部分。免疫共沉淀研究表明，DDB2WT与D1二聚体及其自身相互作用。与WT相比，DDB1基因转染组DDB1的核导入作用较弱。根据这些结果，D1和D2是DNA修复的主要负抑制因子，这可能是由于DDB1与DDB2-WT之间的复合体形成中断和DDB1核输入的破坏所致。(C)2004 Elsevier Inc.保留所有权利。
Damaged DNA-binding protein (DDB) is a heterodimer (DDB1 and DDB2), which is implicated in the repair of UV-irradiated DNA damage. Here we have identified four DDB2 variants from HeLa cells (D1-D4) that are generated by alternative splicing-Analysis of tissue distribution by RT-PCR indicates that D1 is the most highly expressed in human brain and heart. A DNA repair assay revealed that both D1 and D2 are dominant negative inhibitors. Electrophoresis mobility shift assays indicated that D1 and D2 are not part of the damaged DNA-protein complex. Co-immunoprecipitation studies show that DDB2-WT interacts with D1 and itself. Nuclear import of DDB1 was less induced by transfection with D1 than WT. Based on these results, D1 and D2 are dominant negative inhibitors of DNA repair, which is probably due to disruption of complex formation between DDB1 and DDB2-WT and of DDB1 nuclear import. (C) 2004 Elsevier Inc. All rights reserved.