Arabidopsis ABI5 Subfamily Members Have Distinct DNA-Binding and Transcriptional Activities

作者：Soo Young Kim, Jianzhong Ma, Philippe Perret, Zhongsen Li, Terry L. Thomas · 发表于：PLANT PHYSIOLOGY · 年份：2002 · DOI：10.1104/pp.003566 · 被引用次数：150 · 研究领域：Plant Molecular Biology Research、Plant Stress Responses and Tolerance、Plant nutrient uptake and metabolism

A small family of novel basic leucine zipper proteins that includes abscisic acid (ABA)-INSENSITIVE 5 (ABI5) binds to the promoter region of the lea class gene Dc3. The factors, referred to as AtDPBFs (Arabidopsis Dc3 promoter-binding factors), were isolated from an immature seed cDNA library. AtDPBFs bind to the embryo specification and ABA-responsive elements in the Dc3 promoter and are unique in that they can interact with cis-elements that do not contain the ACGT core sequence required for the binding of most other plant basic leucine zipper proteins. Analysis of full-length cDNAs showed that at least five different Dc3 promoter-binding factors are present in Arabidopsis seeds; one of these, AtDPBF-1, is identical to ABI5. As expected, AtDPBF-1/ABI5 mRNA is inducible by exogenous ABA in seedlings. Despite the near identity in their basic domains, AtDPBFs are distinct in their DNA-binding, dimerization, and transcriptional activity.