Laboratory for Cell Biology, Department of Biology, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, People's Republic of China.
Mol Biol Rep. 2010 Feb;37(2):1143-54. doi: 10.1007/s11033-009-9901-z.
It has been demonstrated that the duplicated carbonic anhydrase is induced by salt in the Dunaliella salina (D. salina) and duplicated carbonic anhydrase 1 (DCA1) is a member of carbonic anhydrase family. The purpose of this study was to identify whether both the DCA1 gene and its promoter from D. salina are salt-inducible. In this study, the results of real time RT-PCR showed that the transcripts of DCA1 were induced by gradient concentration of sodium chloride. Subsequently, a structurally novel promoter containing highly repeated GT/AC sequences of the DCA1 gene was isolated, which was able to drive a stable expression of the foreign bar gene in transformed cells of D. salina, and the gradient concentrations of sodium chloride in media paralleled regulations in the levels of both proteins and mRNA of the bar gene driven by the DCA1 promoter. Furthermore, analysis of GUS activities revealed that the salt-inducible expression of the external gus gene was regulated by the promoter fragments containing highly repeated GT sequences, but not by the promoter fragments deleting highly repeated GT sequences. The findings above-mentioned suggest that the highly repeated GT sequence in the DCA1 promoter is involved in the salt-inducible regulation in D. salina and may be a novel salt-inducible element.
已经证明，盐诱导了杜氏盐藻中的碳酸酐酶的复制，而碳酸酐酶 1（DCA1）是碳酸酐酶家族的成员。本研究的目的是确定杜氏盐藻中的 DCA1 基因及其启动子是否都可被盐诱导。在这项研究中，实时 RT-PCR 的结果表明，DCA1 的转录物可被氯化钠的浓度梯度诱导。随后，分离出了一个结构新颖的启动子，该启动子包含 DCA1 基因的高度重复的 GT/AC 序列，能够在杜氏盐藻的转化细胞中稳定表达外源 bar 基因，并且培养基中氯化钠的浓度梯度与 DCA1 启动子驱动的 bar 基因的蛋白和 mRNA 水平的调节平行。此外，GUS 活性分析表明，外部 gus 基因的盐诱导表达受富含高度重复 GT 序列的启动子片段调控，但不受删除高度重复 GT 序列的启动子片段调控。上述发现表明，DCA1 启动子中的高度重复 GT 序列参与了杜氏盐藻中的盐诱导调节，可能是一种新型的盐诱导元件。
