DNA binding activity of the aryl hydrocarbon receptor is sensitive to redox changes in intact cells.
DNA binding activity of the aryl hydrocarbon receptor is sensitive to redox changes in intact cells.
复制标题
芳烃受体的 DNA 结合活性对完整细胞中的氧化还原变化敏感。
DOI：
10.1006/abbi.1998.0851
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Pasco,DS
中科院分区：
文献类型：
--
作者：
Xu,C;Siu,CS;Pasco,DS
通过使用二酰胺和氧化苯胂（PAO），探索了在Hepa-1细胞中芳烃（Ah）受体从其配体结合到DNA结合形式的转化中邻位二硫醇的潜在参与，所述二酰胺和氧化苯胂（PAO）已被证明与选定蛋白质中的邻位巯基特异性地形成稳定的环复合物。预处理与二酰胺和PAO迅速阻止诱导剂依赖性的形成的Ah受体/外源性反应元件复合物检测电泳迁移率变动分析和抑制Ah受体介导的转录。二酰胺和PAO也抑制DNA结合活性的核Ah受体后，其易位到细胞核，但在较小程度上比预处理条件下观察到的。Ah受体对细胞氧化还原变化的敏感性比Sp1高得多，Sp1是一种先前被证明对氧化还原调节非常敏感的转录因子。添加到核提取物中的二酰胺比添加到完整细胞中时更能抑制Ah受体DNA结合。相比之下，Ah受体DNA结合活性更敏感PAO时，它被添加到完整的细胞比当它被添加到核提取物。最后，二硫醇2，3-二巯基丙醇是超过100倍以上的有效性比单硫醇2-巯基乙醇逆转PAO依赖性抑制Ah受体DNA结合活性。这表明邻位巯基残基可能参与Ah受体的DNA结合。
The potential involvement of vicinal dithiols in the transformation of the aryl hydrocarbon (Ah) receptor from its ligand binding to DNA binding form in Hepa-1 cells was explored through the use of diamide and phenylarsine oxide (PAO), which have been shown to specifically form a stable ring complex with vicinal sulfhydryl groups in selected proteins. Pretreatment with diamide and PAO rapidly prevented the inducer-dependent formation of the Ah receptor/xenobiotic response element complex detected by electrophoretic mobility shift assays and suppressed Ah receptor-mediated transcription. Diamide and PAO also inhibited DNA binding activity of the nuclear Ah receptor subsequent to its translocation to the nucleus but to a lesser extent than that observed with pretreatment conditions. The Ah receptor exhibited much higher sensitivity to cellular redox changes than Sp1, a transcription factor previously shown to be very sensitive to redox regulation. Diamide added to nuclear extracts inhibited Ah receptor DNA binding more than when it was added in intact cells. In contrast, Ah receptor DNA binding activity was more sensitive to PAO when it was added to intact cells than when it was added to nuclear extracts. Finally, dithiol 2,3-dimercaptopropanol was over 100 times more effective than monothiol 2-mercaptoethanol in reversing the PAO-dependent inhibition of Ah receptor DNA binding activity. This suggests that vicinal sulhydryl residues may be involved in DNA binding of the Ah receptor.