The Arabidopsis Kelch Repeat F-box E3 Ligase ARKP1 Plays a Positive Role for the Regulation of Abscisic Acid Signaling
The Arabidopsis Kelch Repeat F-box E3 Ligase ARKP1 Plays a Positive Role for the Regulation of Abscisic Acid Signaling
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DOI：
10.1007/s11105-015-0942-2
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发表时间：
2016-11
影响因子：
2.1
通讯作者：
Y. Li;Zhibin Liu;Jianmei Wang;Xu-feng Li;Yi Yang
中科院分区：
文献类型：
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作者：
Y. Li;Zhibin Liu;Jianmei Wang;Xu-feng Li;Yi Yang
泛素化是最常见的翻译后修饰之一。一系列的E3连接酶参与植物非生物胁迫信号传导，调节多种特异性靶蛋白的降解。在这里，我们发现了一个新的基因ABA- response KELCH蛋白1(AtARKP1)，它编码Skp-cullin-F-box （SCF）泛素连接酶复合体的F-box亚基，位于细胞核中，可以被植物激素脱落酸（ABA）诱导。ARKP1与ASK1和ASK2相互作用，ASK1和ASK2将复合物的其余部分连接到F-box蛋白上，这表明它们可能形成SCF泛素连接酶复合物。进一步分析发现，arkp1在种子、莲座叶和根中均有表达。arkp1T-DNA插入突变体植株对ABA不敏感，ABA介导的种子萌发、根伸长和离体叶片失水率的抑制减弱。相比之下，转基因植株对ABA的敏感性增强，对水分亏缺的耐受性增强。因此，与野生型和arkp1突变体相比，arkp1过表达植株ABA和干旱响应标记基因的表达明显上调。综上所述，我们的研究结果表明atarkp1在ABA信号网络中起着积极的作用。
Ubiquitination is one of the most common posttranslational modifications. A series of E3 ligases are implicated in plant abiotic stress signaling, regulating the degradation of multiple specific target proteins. Here, we showed that a novel geneABA-RESPONSE KELCH PROTEIN 1(AtARKP1), which encodes an F-box subunit of Skp-cullin-F-box (SCF) ubiquitin ligase complex, was localized in the nucleus and could be induced by phytohormone abscisic acid (ABA) inArabidopsis. ARKP1 interacted with ASK1 and ASK2, which tethered the rest of the complex to an F-box protein, suggesting that they might form an SCF ubiquitin ligase complex. Further analysis revealed thatARKP1was exclusively expressed in the seed, rosette leaf, and root.arkp1T-DNA insertion mutant plants were insensitive to ABA, displaying reduced ABA-mediated inhibition of seed germination, root elongation, and water loss rate of detached leaves. In contrast, transgenic plants showed enhanced sensitivity to ABA and tolerance to water deficit. Accordingly, the expressions of ABA and drought responsive marker genes were markedly upregulated inARKP1overexpressing plants than the wild-type andarkp1mutant plants. Taken together, our findings suggest thatAtARKP1plays a positive role in ABA signaling network.