title: A structurally novel salt-regulated promoter of duplicated carbonic anhydrase gene 1 from Dunaliella salina.
abstract: 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.
authors.affiliation: Laboratory for Cell Biology, Department of Biology, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, Henan, 450001, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Yumin
authors.initials: Y
authors.lastname: Lu
authors.forename: Lexun
authors.initials: L
authors.lastname: Xue
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
mesh_terms: D001483:Base Sequence; D024401:Carbonic Anhydrase I / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D000460:Chlorophyta / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004305:Dose-Response Relationship, Drug; D020440:Gene Duplication; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D020131:Genes, Duplicate; D008958:Models, Molecular; D008969:Molecular Sequence Data; D030781:Organisms, Genetically Modified; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D012045:Regulatory Sequences, Nucleic Acid / Q000187:drug effects / Q000235:genetics; D055049:Salt Tolerance / Q000235:genetics; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D012965:Sodium Chloride; D024401:Carbonic Anhydrase I