Mga2p is a putative sensor for low temperature and oxygen to induce OLE1 transcription in Saccharomyces cerevisiae.
Mga2p is a putative sensor for low temperature and oxygen to induce OLE1 transcription in Saccharomyces cerevisiae.
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DOI：
10.1006/bbrc.2002.6507
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发表时间：
2002-03
影响因子：
3.1
通讯作者：
Y. Nakagawa;N. Sakumoto;Y. Kaneko;S. Harashima
中科院分区：
文献类型：
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作者：
Y. Nakagawa;N. Sakumoto;Y. Kaneko;S. Harashima
各种低温诱导基因，如脂肪酸去饱和酶基因，是所有生物适应低温环境所必需的。然而，低温信号转导途径在真核生物中尚未被发现。在酵母菌中，Delta9脂肪酸去饱和酶基因OLE1通过泛素/蛋白酶体依赖性加工两个同源内质网膜蛋白Spt23p和Mga2p被激活。我们发现，当培养温度从30℃降至10℃时，OLE1转录瞬间被激活，导致总脂肪酸不饱和程度增加，这种激活在Deltamga2细胞中被大大抑制。尽管Mga2p对于OLE1转录的缺氧激活至关重要，并且其缺氧功能受到不饱和脂肪酸（UFAs）的抑制，但OLE1基因的低温激活不受UFAs的抑制。这些观察结果表明，低温和缺氧信号转导途径有一些共同的成分，而Mga2p是第一个被发现的真核低温和缺氧传感器。
Various low-temperature-inducible genes such as fatty acid desaturase genes are essential for all living organisms to acclimate to low temperature. However, a low-temperature signal transduction pathway has not been identified in eukaryotes. In yeast Saccharomyces cerevisiae, the Delta9 fatty acid desaturase gene OLE1 is activated by ubiquitin/proteasome-dependent processing of two homologous endoplasmic reticulum membrane proteins, Spt23p and Mga2p. We found that OLE1 transcription was transiently activated with resultant increases in the degree of unsaturation of total fatty acids when culture temperature was downshifted from 30 degrees C to 10 degrees C. This activation was greatly depressed in Deltamga2 cells. Although Mga2p is essential for hypoxic activation of OLE1 transcription, and its hypoxic functions are repressed by unsaturated fatty acids (UFAs), low-temperature activation of the OLE1 gene was not repressed by UFAs. These observations suggest that low-temperature and hypoxic signal transduction pathways share some components, and Mga2p is the first identified eukaryotic sensor for low temperature and oxygen.