Cis-trans isomerase gene in psychrophilic Pseudomonas syringae is constitutively expressed during growth and under conditions of temperature and solvent stress
Cis-trans isomerase gene in psychrophilic Pseudomonas syringae is constitutively expressed during growth and under conditions of temperature and solvent stress
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DOI：
10.1007/s00792-005-0435-6
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发表时间：
2005-04-01
期刊：
影响因子：
2.9
通讯作者：
Shivaji, S
中科院分区：
文献类型：
--
作者：
Kiran, MD;Annapoorni, S;Shivaji, S
在最近的一项研究中，我们确定嗜冷假单胞菌（Lz 4 W）在较高温度下生长需要反式单不饱和脂肪酸（Kiran等人，Extremophiles，2004）。cti基因高度保守，与其他假单胞菌的cti基因序列高度一致。（Kiran等人，Extremophiles，2004年）。因此，了解cti基因的表达，以揭示微生物适应高温的分子基础，将是一件有趣的事情。本研究采用RT-PCR方法检测了在高温和溶剂胁迫条件下，赤藓醇甲不同生长阶段cti基因的表达情况。结果表明，cti基因在生长的不同阶段组成型表达，即使在温度和溶剂胁迫条件下，转录水平也没有改变，这意味着观察到的反式单不饱和脂肪酸的增加（Kiran等人，Extremophiles，2004）不受转录控制。还表征了存在于metH和cti基因的基因间区域中的推定启动子。还鉴定了翻译起始位点ATG、Shine-Dalgarno序列AGGA和转录起始位点“C”。这些结果首次提供证据表明，cti基因是组成型表达的正常条件下的生长和温度和溶剂应力的条件下，从而意味着Cti酶是转录后调节。
In a recent study, we established that psychrophilic Pseudomonas syringae (Lz4W) requires trans-monounsaturated fatty acid for growth at higher temperatures (Kiran et al. in Extremophiles, 2004). It was also demonstrated that the cti gene was highly conserved and exhibited high sequence identity with cti of other Pseudomonas spp. (Kiran et al. in Extremophiles, 2004). Therefore it would be interesting to understand the expression of the cti gene so as to unravel the molecular basis of adaptation of microorganisms to high temperature. In the present study, the expression of cti was monitored by RT-PCR analysis during different growth stages and under conditions of high temperature and solvent stress in P. syringae. Results indicated that the cti gene is constitutively expressed during different stages of growth and the transcript level is unaltered even under conditions of temperature and solvent stress implying that the observed increase in trans-monounsaturated fatty acids (Kiran et al. in Extremophiles, 2004) is not under transcriptional control. A putative promoter present in the intergenic region of the metH and cti gene has also been characterized. The translation start site ATG, the Shine-Dalgarno sequence AGGA and the transcription start site "C" were also identified. These results provide evidence for the first time that the cti gene is constitutively expressed under normal conditions of growth and under conditions of temperature and solvent stress thus implying that the Cti enzyme is post-transcriptionally regulated.