Identification and characterization of a low oxygen response element involved in the hypoxic induction of a family of Saccharomyces cerevisiae genes. Implications for the conservation of oxygen sensing in eukaryotes.
Identification and characterization of a low oxygen response element involved in the hypoxic induction of a family of Saccharomyces cerevisiae genes. Implications for the conservation of oxygen sensing in eukaryotes.
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DOI：
10.1074/jbc.m009546200
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发表时间：
2001-04
期刊：
影响因子：
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通讯作者：
M. Vasconcelles;Yide A Jiang;Kevin McDaid;Laura Gilooly;Sharon Wretzel;D. Porter;C. Martin;M. Goldberg
中科院分区：
文献类型：
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作者：
M. Vasconcelles;Yide A Jiang;Kevin McDaid;Laura Gilooly;Sharon Wretzel;D. Porter;C. Martin;M. Goldberg
生物体对氧分压变化的反应能力在很大程度上取决于基因表达的变化。真核细胞中的氧感应和信号转导机制尚不完全清楚。为了进一步确定这些过程，我们研究了酿酒酵母中的Delta9脂肪酸去饱和酶基因OLE1。我们已经证实了先前的数据表明，在低氧和某些过渡金属存在的情况下，OLE1mRNA的表达增加。在铁络合剂1，10-菲咯啉存在的情况下，OLE1的表达也增加。利用OLE1启动子-LacZ报告器构建的OLE1启动子-LacZ报告基因被鉴定为对先前发现的脂肪酸反应元件的一个142碱基对(BP)区域3‘进行关键的OLE1诱导。电迁移率漂移分析证实了在低氧和钴的反应中存在可诱导的频带漂移。突变分析确定了ACTCAACAA为反式激活所必需的非聚体序列。当被放置在LacZ报告结构中异源启动子的上游时，含有该九聚体的20碱基对寡核苷酸通过缺氧和不饱和脂肪酸的抑制而上调。还鉴定了其他酵母基因，它们以类似于OLE1的方式对缺氧和钴做出反应。许多哺乳动物基因也被低氧、钴、镍和铁络合剂上调。因此，以类似方式调控的酵母基因家族的鉴定对于理解真核生物中的氧气感应和信号转导具有重要意义。
An organism's ability to respond to changes in oxygen tension depends in large part on alterations in gene expression. The oxygen sensing and signaling mechanisms in eukaryotic cells are not fully understood. To further define these processes, we have studied the Delta9 fatty acid desaturase gene OLE1 in Saccharomyces cerevisiae. We have confirmed previous data showing that the expression of OLE1 mRNA is increased in hypoxia and in the presence of certain transition metals. OLE1 expression was also increased in the presence of the iron chelator 1,10-phenanthroline. A 142-base pair (bp) region 3' to the previously identified fatty acid response element was identified as critical for the induction of OLE1 in response to these stimuli using OLE1 promoter-lacZ reporter constructs. Electromobility shift assays confirmed the presence of an inducible band shift in response to hypoxia and cobalt. Mutational analysis defined the nonameric sequence ACTCAACAA as necessary for transactivation. A 20-base pair oligonucleotide containing this nonamer confers up-regulation by hypoxia and inhibition by unsaturated fatty acids when placed upstream of a heterologous promoter in a lacZ reporter construct. Additional yeast genes were identified which respond to hypoxia and cobalt in a manner similar to OLE1. A number of mammalian genes are also up-regulated by hypoxia, cobalt, nickel, and iron chelators. Hence, the identification of a family of yeast genes regulated in a similar manner has implications for understanding oxygen sensing and signaling in eukaryotes.