Transcriptional Regulation of Desaturase Genes in Pichia pastoris GS115
Transcriptional Regulation of Desaturase Genes in Pichia pastoris GS115
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毕赤酵母 GS115 去饱和酶基因的转录调控
DOI：
10.1007/s11745-012-3712-z
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发表时间：
2012-09
期刊：
影响因子：
1.9
通讯作者：
Li, Ming-Chun
中科院分区：
文献类型：
--
作者：
Shi, Tong-Lei;Zhang, Biao;Xing, Lai-Jun;Li, Ming-Chun
本文在转录水平上研究了低温和外源脂肪酸对毕赤酵母指数生长后期去饱和酶基因的调控。基因表达的时程研究表明，四个去饱和酶基因的mRNA水平被低温快速和短暂地增强，并被外源油酸抑制。硬脂酸对Fad 12和Fad 15的mRNA水平无明显抑制作用，而对Fad 9A和Fad 9 B的mRNA水平略有增加。使用启动子-报告基因构建体，我们证明了pFAD 15启动子活性以时间依赖性方式被低温诱导，并以剂量和时间依赖性方式被不饱和脂肪酸降低。此外，mRNA丰度和相应脂肪酸的产生之间没有绝对的相关性。Spt 23的破坏导致Fad 9A和Fad 9 B的转录水平降低，但对其他去饱和酶基因的影响不大。与此一致，在Δ Spt 23突变体的稳定期细胞中，油酸（奥拉）的相对含量明显降低，亚油酸和ALA的相对含量不同程度地升高。进一步分析发现，Spt 23基因被破坏后，低温激活和奥拉抑制对Fad 9 A和Fad 9 B表达的影响似乎消失，这表明Spt 23 p对两个Δ9-去饱和酶基因的内部表达是必需的，并且可能参与调节Δ9-去饱和酶基因响应于外部刺激的转录，从而在奥拉的合成中发挥作用。
Here we investigated the regulation of Pichia pastoris desaturase genes by low temperature and exogenous fatty acids in the late‐exponential phase at the transcriptional level. Time‐course studies of gene expression showed that mRNA levels of four desaturase genes were rapidly and transiently enhanced by low temperature and suppressed by exogenous oleic acid. Stearic acid showed no obvious repression of mRNA levels of Fad12 and Fad15 and a slight increase in Fad9A and Fad9B mRNA levels. Using a promoter–reporter gene construct, we demonstrated that the pFAD15 promoter activity was induced by low temperature in a time‐dependent manner and reduced in a dose‐ and time‐dependent manner by unsaturated fatty acids. Also, there was no absolute correlation between mRNA abundance and production of corresponding fatty acids. Disruption of Spt23 resulted in a decrease in transcript levels of Fad9A and Fad9B, but had little effect on the other desaturase genes. Consistent with these observations, a decrease in the relative amount of oleic acid (OLA) and an increase in the relative content of linoleic acid and ALA with different degrees were clearly observed in the stationary phase cells of ΔSpt23 mutant. Further analysis showed that the effect of low‐temperature activation and OLA inhibition on expression of Fad9A and Fad9B seemed to disappear after disruption of the Spt23 gene, which indicated that Spt23p is essential for the expression of two Δ9‐desaturase genes internally and probably involved in the regulation of Δ9‐desaturase genes transcription in response to external stimuli, and thereby plays a role in the synthesis of OLA.
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影响因子：
5.3
作者：
S. Zhang;T. Burkett;I. Yamashita;D. Garfinkel
通讯作者：
S. Zhang;T. Burkett;I. Yamashita;D. Garfinkel
影响因子：
3.1
作者：
Y. Nakagawa;N. Sakumoto;Y. Kaneko;S. Harashima
通讯作者：
Y. Nakagawa;N. Sakumoto;Y. Kaneko;S. Harashima
影响因子：
6
作者：
Calder, Philip C.;Yaqoob, Parveen
通讯作者：
Yaqoob, Parveen
影响因子：
--
作者：
Jiang, YD;Vasconcelles, MJ;Goldberg, MA
通讯作者：
Goldberg, MA
影响因子：
2.6
作者：
HILL, JE;MYERS, AM;TZAGOLOFF, A
通讯作者：
TZAGOLOFF, A