Differences in the control of the temperature-dependent expression of four genes for desaturases in Synechocystis sp. PCC 6803
Differences in the control of the temperature-dependent expression of four genes for desaturases in Synechocystis sp. PCC 6803
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DOI：
10.1046/j.1365-2958.1997.5641912.x
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发表时间：
1997-09-01
影响因子：
3.6
通讯作者：
Murata, N
中科院分区：
文献类型：
--
作者：
Los, DA;Ray, MK;Murata, N
蓝细菌能够使其膜脂中的脂肪酸去饱和以响应温度的降低。蓝细菌集胞藻属PCC 6803含有四种去饱和酶，其特异性催化脂肪酸的Δ 6、Δ 9、Δ 12和ω 3位置的去饱和。从编码Delta 6、Delta 12和omega 3去饱和酶的基因转录的mRNA水平在温度从34 ℃降低到22 ℃时增加约10倍，但速率不同，而Delta 9去饱和酶的mRNA水平保持恒定。mRNA水平的增加是由转录增强和mRNA在低温下稳定性增加引起的。蛋白质印迹分析表明，Delta 6、Delta 12和Omega 3去饱和酶的水平在低温下以不同的速率增加，而Delta 9去饱和酶的水平保持不变。这些观察结果表明，四种去饱和酶基因的表达受温度以不同方式调节。
Cyanobacteria are capable of desaturating the fatty acids in their membrane lipids in response to decreases in temperature. The cyanobacterium, Synechocystis sp. PCC 6803, contains four desaturases, which specifically catalyse desaturation at the Delta 6, Delta 9, Delta 12 and omega 3 positions of fatty acids. The levels of the mRNAs transcribed from the genes that encode the Delta 6, Delta 12 and omega 3 desaturases increased about 10-fold, but at different rates, upon a decrease in temperature from 34 degrees C to 22 degrees C, whereas the level of the mRNA for the Delta 9 desaturase remained constant. The increases in the levels of mRNAs were caused both by the enhanced transcription and by the increased stability of the mRNAs at the tow temperature. Western blotting analysis demonstrated that levels of the Delta 6, Delta 12 and omega 3 desaturases increased at different rates at the low temperature, while that of the Delta 9 desaturase remained constant. These observations indicate that the expression of the genes for the four desaturases is regulated by temperature in different ways.