IDENTIFICATION OF BINDING-SITES FOR TRANSCRIPTION FACTORS NF-KAPPA-B AND AP-2 IN THE PROMOTER REGION OF THE HUMAN HEME OXYGENASE-1 GENE
IDENTIFICATION OF BINDING-SITES FOR TRANSCRIPTION FACTORS NF-KAPPA-B AND AP-2 IN THE PROMOTER REGION OF THE HUMAN HEME OXYGENASE-1 GENE
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DOI：
10.1073/pnas.91.13.5987
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发表时间：
1994-06-21
影响因子：
11.1
通讯作者：
ABRAHAM, NG
中科院分区：
文献类型：
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作者：
LAVROVSKY, Y;SCHWARTZMAN, ML;ABRAHAM, NG
血红素加氧酶 (HO) 是血红素分解代谢中的限速酶，其活性由许多因素诱导，包括其底物血红素、重金属、紫外线辐射和其他有害氧化剂条件。我们检查了人类 HO-1 基因启动子区域中多个调控元件的存在，这可能解释了它对不同物质或影响的反应的诱导。血红素处理增加了人红白血病细胞系 K562 中的 HO 活性和 HO-1 mRNA。使用包含已知转录因子（包括 AP-1、AP-2、Sp1、NF-kappa B、CTF/NF1、TFIID、OKT1 和 CREB）结合位点的特定寡核苷酸探针以及包含血清、金属和糖皮质激素响应元件的寡核苷酸，对血红素处理细胞和对照细胞的核蛋白提取物进行电泳迁移率变动分析，结果表明 NF-kappa B 和 AP-2 转录有特异性且显着的增加因素，以及较小程度上 AP-1 的增加。与对照、未处理的细胞相比，没有观察到其他转录因子的显着增加。使用纯化的转录因子进行的 DNase I 足迹分析揭示了人 HO-1 基因启动子区域近端部分存在 NF-κ B 和 AP-2 结合位点。此外，HO-1启动子区域的核苷酸序列分析表明受保护区域包含NF-κB和AP-2共有结合位点。转录因子（如 NF-κ B 和 AP-2）结合调节序列的存在，其激活与细胞对损伤的立即反应相关，可能表明 HO-1 在组织损伤的防御机制中可能发挥重要作用。
Heme oxygenase (HO) is the rate-limiting enzyme in heme catabolism and its activity is induced by many agents, including its substrate heme, heavy metals, UV radiation, and other injurious oxidant conditions. We examined the presence of several regulatory elements in the promoter region of the human HO-1 gene which could possibly account for its induction in response to diverse agents or influences. Heme treatment increased both HO activity and HO-1 mRNA in the human erythroleukemic cell line K562. Electrophoretic mobility-shift assays of nuclear protein extracts from heme-treated and control cells with specific oligonucleotide probes containing binding sites for known transcription factors, including AP-1, AP-2, Sp1, NF-kappa B, CTF/NF1, TFIID, OKT1, and CREB, and oligonucleotides containing serum-, metal-, and glucocorticoid-responsive elements demonstrated a specific and marked increase in the NF-kappa B and AP-2 transcription factors and, to a lesser extent, an increase in AP-1. No significant increase in other transcription factors over the control, untreated cells was observed. DNase I footprint assays using purified transcription factors revealed the presence of NF-kappa B and AP-2 binding sites in the proximal part of the promoter region of the human HO-1 gene. Moreover, nucleotide sequence analysis of the HO-1 promoter region showed that the protected regions encompassed NF-kappa B and AP-2 consensus binding sites. The presence of regulatory sequences for the binding of transcription factors such as NF-kappa B and AP-2, whose activation is associated with the immediate response of the cell to an injury, may be an indication of the important role which HO-1 may play in defense mechanisms against tissue injury.