DREB2C Interacts with ABF2, a bZIP Protein Regulating Abscisic Acid-Responsive Gene Expression, and Its Overexpression Affects Abscisic Acid Sensitivity
DREB2C Interacts with ABF2, a bZIP Protein Regulating Abscisic Acid-Responsive Gene Expression, and Its Overexpression Affects Abscisic Acid Sensitivity
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DOI：
10.1104/pp.110.154617
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发表时间：
2010-06-01
期刊：
影响因子：
7.4
通讯作者：
Kim, Soo Young
中科院分区：
文献类型：
--
作者：
Lee, Sun-ji;Kang, Jung-youn;Kim, Soo Young
ABF 2是一种碱性亮氨酸拉链蛋白，调节脱落酸（阿坝）依赖的胁迫响应基因表达。我们进行了酵母双杂交筛选分离基因编码ABF 2相互作用蛋白在拟南芥（拟南芥）。对获得的阳性克隆进行分析，发现其中两个克隆编码AP 2结构域蛋白，其与AtERF 48/DREB 2C相同。该蛋白在体外可与C-重复/脱水反应元件结合，具有转录活性，将其命名为DREB 2C。为了确定其功能，我们产生了DREB 2C过表达株并研究了它们的表型。转基因植株在萌发和成苗阶段对阿坝高度敏感，而幼苗的初生根伸长对阿坝不敏感，表明DREB 2C功能依赖于发育阶段。DREB 2C过表达株系也显示出改变的胁迫反应;而植物对脱水敏感，它们是耐寒和耐热的。我们进一步表明，其他AP 2结构域蛋白，DREB 1A和DREB 2A，与ABF 2和其他ABF家族成员，ABF 3和ABF 4，与DREB 2C相互作用。以前，其他人证明ABF和DREB家族成员合作激活ABA应答基因的转录。我们的结果表明，这两类转录因子的合作可能涉及物理相互作用。
ABF2 is a basic leucine zipper protein that regulates abscisic acid (ABA)-dependent stress-responsive gene expression. We carried out yeast two-hybrid screens to isolate genes encoding ABF2-interacting proteins in Arabidopsis (Arabidopsis thaliana). Analysis of the resulting positive clones revealed that two of them encode an AP2 domain protein, which is the same as AtERF48/DREB2C. This protein, which will be referred to as DREB2C, could bind C-repeat/dehydration response element in vitro and possesses transcriptional activity. To determine its function, we generated DREB2C overexpression lines and investigated their phenotypes. The transgenic plants were ABA hypersensitive during germination and seedling establishment stages, whereas primary root elongation of seedlings was ABA insensitive, suggesting developmental stage dependence of DREB2C function. The DREB2C overexpression lines also displayed altered stress response; whereas the plants were dehydration sensitive, they were freezing and heat tolerant. We further show that other AP2 domain proteins, DREB1A and DREB2A, interact with ABF2 and that other ABF family members, ABF3 and ABF4, interact with DREB2C. Previously, others demonstrated that ABF and DREB family members cooperate to activate the transcription of an ABA-responsive gene. Our result implies that the cooperation of the two classes of transcription factors may involve physical interaction.