Arabidopsis thaliana ethylene-responsive element binding protein (AtEBP), an ethylene-inducible, GCC box DNA-binding protein interacts with an ocs element binding protein
Arabidopsis thaliana ethylene-responsive element binding protein (AtEBP), an ethylene-inducible, GCC box DNA-binding protein interacts with an ocs element binding protein
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DOI：
10.1073/pnas.94.11.5961
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发表时间：
1997-05-27
影响因子：
11.1
通讯作者：
Singh, KB
中科院分区：
文献类型：
--
作者：
Buttner, M;Singh, KB
Ocs元件是一组启动子序列，是侵染植物中病原基因和植物防御基因表达所必需的。ocs元件结合因子（OBF）基因属于一类特殊的碱性亮氨酸拉链（bZIP）转录因子，已在许多植物中分离到。利用OBF 4蛋白质-蛋白质相互作用筛选，我们分离到AtEBP，一种含有新的DNA结合结构域AP 2/EREBP结构域的拟南芥蛋白，含有该结构域的一类蛋白是烟草乙烯反应元件结合蛋白（EREBP）。EREBP与GCC盒结合，GCC盒赋予乙烯对许多致病相关（PR）基因启动子的响应性，AtEBP在野生型植物中的表达可被外源乙烯诱导，并且AtEBP转录物在乙烯调节途径组成型激活的cCL-I突变体中增加。电泳迁移率变化测定和DNA酶I足迹分析显示AtEBP可以特异性地与GCC盒结合。有趣的是，在ocs元件非常活跃的愈伤组织中检测到最高水平的AtEBP表达。先前已经观察到GCC盒与ocs元件或相关G盒序列的协同作用，例如，在乙烯诱导的PR基因启动子的表达中，我们的研究结果表明，交叉-EREBP和bZIP转录因子之间发生偶联，因此在植物防御反应期间调节基因表达可能是重要的。
Ocs elements are a group of promoter sequences required for the expression of both pathogen genes in infected plants and plant defense genes, Genes for ocs element binding factors (OBFs), belonging to a specific class of basic-region leucine zipper (bZIP) transcription factors, have been isolated in a number of plants, Using protein-protein interaction screening with OBF4 we have isolated AtEBP, an Arabidopsis protein that contains a novel DNA-binding domain, the AP2/EREBP domain, One class of proteins that contain this domain are the tobacco ethylene-responsive element binding proteins (EREBPs). The EREBPs bind the GCC box that confers ethylene responsiveness to a number of pathogenesis related (PR) gene promoters, AtEBP expression is inducible by exogenous ethylene in wild-type plants and AtEBP transcripts are increased in the ctrl-1 mutant, where ethylene-regulated pathways are constitutively active, Electrophoretic mobility-shift assay and DNase I footprint analysis revealed that AtEBP can specifically bind to the GCC box, Interestingly, the highest level of AtEBP expression was detected in callus tissue, where ocs elements are very active, Synergistic effects of the GCC box with ocs elements or the related G-box sequence have been previously observed, for example, in the ethylene-induced expression of a PR gene promoter, Our results suggest that cross-coupling between EREBP and bZIP transcription factors occurs and may therefore be important in regulating gene expression during the plant defense response.