The Protein Kinase CK2 Mediates Cross-Talk between Auxin- and Salicylic Acid-Signaling Pathways in the Regulation of PINOID Transcription.
The Protein Kinase CK2 Mediates Cross-Talk between Auxin- and Salicylic Acid-Signaling Pathways in the Regulation of PINOID Transcription.
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DOI：
10.1371/journal.pone.0157168
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Martínez MC
中科院分区：
文献类型：
--
作者：
Armengot L;Caldarella E;Marquès-Bueno MM;Martínez MC
蛋白激酶CK2是一种普遍存在且高度保守的酶，其活性对真核细胞至关重要。我们最近证明了CK2调节拟南芥中水杨酸（SA）的稳态，并且CK2和SA之间的功能相互作用维持了PIN- formed （PIN）基因的转录表达。在这项工作中，我们发现CK2在PINOID （PID）的转录调控中也起着关键作用，PINOID是一种AGC蛋白激酶，调节生长素外排转运体的顶端/基部定位。我们发现，生长素和SA上调了PID转录，CK2参与了这两种途径。一方面，CK2活性是蛋白质体依赖性降解AXR3所必需的，AXR3是生长素转录抑制因子AUX/IAA家族的成员，必须被降解才能激活生长素应答基因表达。另一方面，通过使用不能积累SA的拟南芥NahG转基因植株，证实了CK2在SA稳态中的作用，并间接参与SA驱动的PID转录。总之，我们的研究结果证明了CK2在生长素和sa信号传导之间的负互扰中起着功能联系的作用。
The protein kinase CK2 is a ubiquitous and highly conserved enzyme, the activity of which is vital for eukaryotic cells. We recently demonstrated that CK2 modulates salicylic acid (SA) homeostasis in Arabidopsis thaliana, and that functional interplay between CK2 and SA sustains transcriptional expression of PIN-FORMED (PIN) genes. In this work, we show that CK2 also plays a key role in the transcriptional regulation of PINOID (PID), an AGC protein kinase that modulates the apical/basal localization of auxin-efflux transporters. We show that PID transcription is up-regulated by auxin and by SA and that CK2 is involved in both pathways. On the one hand, CK2 activity is required for proteosome-dependent degradation of AXR3, a member of the AUX/IAA family of auxin transcriptional repressors that must be degraded to activate auxin-responsive gene expression. On the other hand, the role of CK2 in SA homeostasis and, indirectly, in SA-driven PID transcription, was confirmed by using Arabidopsis NahG transgenic plants, which cannot accumulate SA. In conclusion, our results evidence a role for CK2 as a functional link in the negative cross-talk between auxin- and SA-signaling.