The homologous ABI5 and EEL transcription factors function antagonistically to fine-tune gene expression during late embryogenesis
The homologous ABI5 and EEL transcription factors function antagonistically to fine-tune gene expression during late embryogenesis
复制标题
DOI：
10.1105/tpc.000869
复制
发表时间：
2002-06-01
期刊：
影响因子：
11.6
通讯作者：
Parcy, F
中科院分区：
文献类型：
--
作者：
Bensmihen, S;Rippa, S;Parcy, F
在拟南芥中，碱性亮氨酸拉链转录因子ABI 5激活几个胚胎发生晚期丰富的基因，包括AtEm 1和AtEm 6。然而，许多其他种子成熟基因的表达不依赖于ABI 5。我们研究了ABI 5同源物也参与种子成熟过程中基因表达调控的可能性。我们在拟南芥基因组序列中鉴定了13个ABI 5相关基因。RNA凝胶印迹分析表明，这些基因中有7个在种子成熟过程中是活跃的，它们显示出不同的表达动力学。我们分离并表征了其中一个基因AtbZIP 12/EEL的两个突变等位基因。与abi 5不同，eel突变并不抑制我们监测的任何成熟标记基因的表达。相反，AtEm 1和AtEm 6 mRNA的积累增强鳗鱼突变体种子相比，野生型种子。凝胶迁移率变动分析，结合分析的EEL和abi 5突变之间的遗传相互作用，表明ABI 5和EEL竞争相同的结合位点内的AtEm 1启动子。这项研究说明了两个同源转录因子如何发挥拮抗作用，微调基因表达。
In Arabidopsis, the basic leucine zipper transcription factor ABI5 activates several late embryogenesis-abundant genes, including AtEm1 and AtEm6. However, the expression of many other seed maturation genes is independent of ABI5. We investigated the possibility that ABI5 homologs also participate in the regulation of gene expression during seed maturation. We identified 13 ABI5-related genes in the Arabidopsis genomic sequence. RNA gel blot analysis showed that seven of these genes are active during seed maturation and that they display distinct expression kinetics. We isolated and characterized two mutant alleles of one of these genes, AtbZIP12/EEL. Unlike abi5, the eel mutations did not inhibit the expression of any of the maturation marker genes that we monitored. On the contrary, the accumulation of the AtEm1 and AtEm6 mRNAs was enhanced in eel mutant seeds compared with wild-type seeds. Gel mobility shift assays, combined with analysis of the genetic interactions among the eel and abi5 mutations, indicated that ABI5 and EEL compete for the same binding sites within the AtEm1 promoter. This study illustrates how two homologous transcription factors can play antagonistic roles to fine-tune gene expression.