Repression of the Arabidopsis thaliana jasmonic acid/ethylene-induced defense pathway by TGA-interacting glutaredoxins depends on their C-terminal ALWL motif.
Repression of the Arabidopsis thaliana jasmonic acid/ethylene-induced defense pathway by TGA-interacting glutaredoxins depends on their C-terminal ALWL motif.
复制标题
DOI：
10.1093/mp/ssr113
复制
发表时间：
2012-07
期刊：
影响因子：
27.5
通讯作者：
Mark Zander;Shuxia Chen;Julia Imkampe;Corinna Thurow;C. Gatz
中科院分区：
文献类型：
--
作者：
Mark Zander;Shuxia Chen;Julia Imkampe;Corinna Thurow;C. Gatz
谷氧还蛋白是小的热稳定的氧化还原酶，其将电子从谷胱甘肽（GSH）转移到氧化的半胱氨酸残基，从而有助于蛋白质的完整性和调节。在拟南芥中，花谷氧还蛋白ROXY 1和ROXY 2和病原体诱导的ROXY 19/GRX 480与TGACG（TGA）基序结合家族的bZIP转录因子相互作用。ROXY 1、ROXY 2和TGA因子PERIANTHIA、TGA 9和TGA 10在花发育中起重要作用。相反，异位表达的ROXY 19/GRX 480负调控茉莉酸（JA）/乙烯（ET）诱导的防御基因的表达，通过一个未知的机制，需要进化枝II转录因子TGA 2，TGA 5，和/或TGA 6。在这里，我们报告说，至少有17的21个陆地植物特有的谷氧还蛋白编码的拟南芥基因组中与TGA 2在酵母双杂交系统的相互作用。为了研究它们干扰JA/ET诱导基因表达的能力，我们开发了一个瞬时表达系统。转录因子EIN 3（乙烯不敏感3）激活的ORA 59（八癸烷类反应性拟南芥AP 2/ERF结构域蛋白59）启动子被共表达的ROXY 19/GRX 480抑制。抑制依赖于ROXY 19/GRX 480 C-末端的L**LL基序。这个推定的蛋白质相互作用结构域最近被描述为TGA/ROXY相互作用所必需的。17个测试的ROXY蛋白中的10个抑制了ORA 59启动子活性，这与C-末端ALWL基序的存在相关，该基序对于ROXY 1在花发育中的功能是必不可少的。ROXY 19/GRX 480介导的抑制依赖于GSH结合位点，这表明TGA因子或未知靶蛋白的氧化还原修饰对于抑制ORA 59启动子活性是重要的。
Glutaredoxins are small heat-stable oxidoreductases that transfer electrons from glutathione (GSH) to oxidized cysteine residues, thereby contributing to protein integrity and regulation. In Arabidopsis thaliana, floral glutaredoxins ROXY1 and ROXY2 and pathogen-induced ROXY19/GRX480 interact with bZIP transcription factors of the TGACG (TGA) motif-binding family. ROXY1, ROXY2, and TGA factors PERIANTHIA, TGA9, and TGA10 play essential roles in floral development. In contrast, ectopically expressed ROXY19/GRX480 negatively regulates expression of jasmonic acid (JA)/ethylene (ET)-induced defense genes through an unknown mechanism that requires clade II transcription factors TGA2, TGA5, and/or TGA6. Here, we report that at least 17 of the 21 land plant-specific glutaredoxins encoded in the Arabidopsis genome interact with TGA2 in a yeast-two-hybrid system. To investigate their capacity to interfere with the expression of JA/ET-induced genes, we developed a transient expression system. Activation of the ORA59 (OCTADECANOID-RESPONSIVE ARABIDOPSIS AP2/ERF-domain protein 59) promoter by transcription factor EIN3 (ETHYLENE INSENSITVE 3) was suppressed by co-expressed ROXY19/GRX480. Suppression depended on the L**LL motif in the C-terminus of ROXY19/GRX480. This putative protein interaction domain was recently described as being essential for the TGA/ROXY interaction. Ten of the 17 tested ROXY proteins suppressed ORA59 promoter activity, which correlated with the presence of the C-terminal ALWL motif, which is essential for ROXY1 function in flower development. ROXY19/GRX480-mediated repression depended on the GSH binding site, suggesting that redox modification of either TGA factors or as yet unknown target proteins is important for the suppression of ORA59 promoter activity.