Redox regulation of transcriptional activity of retinoic acid receptor by thioredoxin glutathione reductase (TGR)
Redox regulation of transcriptional activity of retinoic acid receptor by thioredoxin glutathione reductase (TGR)
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DOI：
10.1016/j.bbrc.2009.09.097
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发表时间：
2009-12-11
影响因子：
3.1
通讯作者：
Um, Soo-Jong
中科院分区：
文献类型：
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作者：
Park, Ui-Hyun;Han, Hye-Sook;Um, Soo-Jong
视黄酸受体（RAR）作为视黄酸（RA）响应性转录激活剂之一，通过调节RA靶基因表达来介导多种生物过程。在研究 RAR 活性如何受到调节时，我们分离出了硫氧还蛋白谷胱甘肽还原酶 (TGR)，它是硫氧还蛋白还原酶家族的成员。系统性酵母双杂交检测表明，在 RA 存在的情况下，TGR 通过位于 TGR Grx 和 TrxR 结构域之间的 LxxLL 基序（NR 盒）与 RAR 相互作用。 GST 下拉和免疫沉淀测定证实了这种相互作用。 TGR 分别在 TGR 缺陷的 NIH3T3 或 TGR 丰富的 TM4 Sertoli 细胞中稳定过表达或敲低，表明 TGR 通过增加 RAR 的 DNA 结合能力来增强 RAR 的转录活性，并在活性氧 (ROS) 损伤后恢复 RAR 活性。此外，我们证明 RAR 响应 ROS 的反式激活潜力和 DNA 结合活性取决于 TGR 的细胞水平。总的来说，我们的数据表明 TGR 的氧化还原调节功能可以保护 RAR 的 DNA 结合活性免受细胞 ROS 损伤。 (C) 2009 Elsevier Inc. 保留所有权利。
The retinoic acid receptor (RAR), as one of the retinoic acid (RA)-responsive transcription activators, mediates various biological processes by regulating RA target gene expression. In studying how RAR activity is regulated, we isolated thioredoxin glutathione reductase (TGR), a member of the thioredoxin reductase family. Systematic yeast two-hybrid assays showed that in the presence of RA, TGR interacts with RAR via the LxxLL motif(NR box) located between the Grx and TrxR domains of TGR. This interaction was confirmed by GST pull-down and immunoprecipitation assays. The stable over-expression or knockdown of TGR in TGR-deficient NIH3T3 or TGR-abundant TM4 Sertoli cells, respectively, revealed that TGR enhances the transcriptional activity of RAR by increasing its DNA-binding capacity and restores RAR activity after impairment by reactive oxygen species (ROS). Furthermore, we demonstrated that the transactivation potential and DNA-binding activity of RAR in response to ROS depends on the cellular level of TGR. Overall, our data suggest that the redox regulation function of TGR protects the DNA-binding activity of RAR against cellular ROS damage. (C) 2009 Elsevier Inc. All rights reserved.