ICE1 Ser403 is necessary for protein stabilization and regulation of cold signaling and tolerance
ICE1 Ser403 is necessary for protein stabilization and regulation of cold signaling and tolerance
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DOI：
10.1111/j.1365-313x.2011.04589.x
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发表时间：
2011-07-01
期刊：
影响因子：
7.2
通讯作者：
Hasegawa, Paul M.
中科院分区：
文献类型：
--
作者：
Miura, Kenji;Ohta, Masaru;Hasegawa, Paul M.
ICE 1是MYC型转录因子，在诱导CBF 3/DREB 1A中发挥重要作用，调节冷信号传导和耐受。在这里，我们发现，丝氨酸403的ICE 1参与调节的反式激活和稳定的ICE 1蛋白。丝氨酸403被丙氨酸取代增强了ICE 1在拟南芥原生质体中的反式激活活性。过量表达ICE 1（S403 A）的拟南芥比ICE 1（WT）具有更强的抗冻性，并且CBF 3/DREB 1A、COR 47和KIN 1等冷调节基因的表达量在过量表达ICE 1（S403 A）的拟南芥中得到增强。此外，ICE 1（S403 A）蛋白水平在冷处理后没有变化，而ICE 1（WT）蛋白水平降低。有趣的是，体内ICE 1（S403 A）蛋白的多泛素化明显被阻断。这些结果表明，丝氨酸403的ICE 1的反式激活和冷诱导降解的ICE 1通过泛素/26 S蛋白酶体途径的作用，表明丝氨酸403是一个关键的残基为衰减冷应激反应的HOS 1介导的降解ICE 1。
ICE1, a MYC-type transcription factor, has an important role in the induction of CBF3/DREB1A for regulation of cold signaling and tolerance. Here we reveal that serine 403 of ICE1 is involved in regulating the transactivation and stability of the ICE1 protein. Substitution of serine 403 by alanine enhanced the transactivational activity of ICE1 in Arabidopsis protoplasts. Over-expression of ICE1(S403A) conferred more freezing tolerance than ICE1(WT) in Arabidopsis, and the expression of cold-regulated genes such as CBF3/DREB1A, COR47 and KIN1 was enhanced in plants over-expressing ICE1(S403A). Furthermore, the ICE1(S403A) protein level was not changed after cold treatment, whereas the ICE1(WT) protein level was reduced. Interestingly, polyubiquitylation of the ICE1(S403A) protein in vivo was apparently blocked. These results demonstrate that serine 403 of ICE1 has roles in both transactivation and cold-induced degradation of ICE1 via the ubiquitin/26S proteasome pathway, suggesting that serine 403 is a key residue for the attenuation of cold-stress responses by HOS1-mediated degradation of ICE1.