STRUCTURAL ORGANIZATION OF THE HUMAN HEME OXYGENASE GENE AND THE FUNCTION OF ITS PROMOTER
STRUCTURAL ORGANIZATION OF THE HUMAN HEME OXYGENASE GENE AND THE FUNCTION OF ITS PROMOTER
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DOI：
10.1111/j.1432-1033.1989.tb14583.x
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发表时间：
1989-02-15
期刊：
影响因子：
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通讯作者：
YOSHIDA, T
中科院分区：
文献类型：
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作者：
SHIBAHARA, S;SATO, M;YOSHIDA, T
人类血红素加氧酶是由其底物血红素诱导的，但不是由热休克诱导的[Yoshida等人。(1988)欧元。J.生物化学。171,457-461]。为了研究血红素介导的人血红素加氧酶诱导的分子机制，我们分离并鉴定了血红素加氧酶的基因组克隆。人类血红素加氧酶基因(HO基因)全长约14kb，由5个外显子组成。通过S1核酸酶作图和引物延伸分析，确定了转录起始点。利用HeLa全细胞提取液，我们证实克隆的HO基因的转录在指定的起始点被准确地启动。在其5‘侧翼区，在起始点上游367bp处存在一个潜在的热休克元件(HSE)，但与大鼠血红素加氧酶不同的是，人酶不受热休克诱导。因此，我们分析了热休克对携带人HO基因启动子的嵌合基因瞬时表达的影响，该融合基因连接到小鼠无色素性黑素瘤细胞。含有潜在HSE的人HO基因5‘侧翼区不能提供热诱导产生gptRNA的能力，这表明人HO基因的HSE不起作用。
Human heme oxygenase is induced by its substrate heme, but not induced by heat shock [Yoshida et al. (1988)Eur. J. Biochem. 171, 457 – 461]. In order to study the molecular mechanisms of heme‐mediated induction of human heme oxygenase, we have isolated and characterized the genomic clones for heme oxygenase. The human heme oxygenase gene (HO gene) is about 14 kb long and organized into five exons. The transcription initiation site was identified by S1 nuclease mapping and primer‐extension analyses. Using HeLa whole cell extracts, we confirmed that the transcription of the cloned HO gene is initiated accurately at the assigned initiation site. In its 5′‐flanking region, a potential heat‐shock element (HSE) is present 367 bp upstream from the initiation site, although, in contrast to rat heme oxygenase, human enzyme is not induced by heat shock. We therefore analyzed the effects of heat shock on the transient expression of chimeric fusion genes harboring the promoter of the human HO gene ligated to theEscherichia coligenegptin mouse amelanotic melanoma cells. The 5′‐flanking region of the human HO gene bearing a potential HSE failed to confer the heat‐inducibility ofgptRNA production, suggesting that the HSE of the human HO gene is not functional.