Stress-Induced GSK3 Regulates the Redox Stress Response by Phosphorylating Glucose-6-Phosphate Dehydrogenase in Arabidopsis
Stress-Induced GSK3 Regulates the Redox Stress Response by Phosphorylating Glucose-6-Phosphate Dehydrogenase in Arabidopsis
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DOI：
10.1105/tpc.112.101279
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发表时间：
2012-08-01
期刊：
影响因子：
11.6
通讯作者：
Jonak, Claudia
中科院分区：
文献类型：
--
作者：
Dal Santo, Silvia;Stampfl, Hansjoerg;Jonak, Claudia
不同的压力，如高盐条件下，导致活性氧（ROS）的增加，需要一个氧化还原应激反应。然而，很少有人知道的信号通路，调节抗氧化系统，以抵消氧化应激。在这里，我们表明来自拟南芥的糖原合成酶激酶3（ASK alpha）通过激活Glc-6-磷酸脱氢酶（G6 PD）来调节胁迫耐受性，这对于维持细胞氧化还原平衡至关重要。应激激活的ASK α的丧失导致G6 PD活性降低、ROS水平升高和对盐应激的敏感性增强。相反，过表达ASK α的植物响应于胁迫具有增加的G6 PD活性和低水平的ROS，并且对盐胁迫更耐受。ASK α通过磷酸化进化上保守的Thr-467刺激特定细胞溶质G6 PD同种型的活性，Thr-467与共底物结合有关。我们的研究结果揭示了一种新的机制，G6 PD适应性调节是至关重要的细胞应激反应。
Diverse stresses such as high salt conditions cause an increase in reactive oxygen species (ROS), necessitating a redox stress response. However, little is known about the signaling pathways that regulate the antioxidant system to counteract oxidative stress. Here, we show that a Glycogen Synthase Kinase3 from Arabidopsis thaliana (ASK alpha) regulates stress tolerance by activating Glc-6-phosphate dehydrogenase (G6PD), which is essential for maintaining the cellular redox balance. Loss of stress-activated ASK alpha leads to reduced G6PD activity, elevated levels of ROS, and enhanced sensitivity to salt stress. Conversely, plants overexpressing ASK alpha have increased G6PD activity and low levels of ROS in response to stress and are more tolerant to salt stress. ASK alpha stimulates the activity of a specific cytosolic G6PD isoform by phosphorylating the evolutionarily conserved Thr-467, which is implicated in cosubstrate binding. Our results reveal a novel mechanism of G6PD adaptive regulation that is critical for the cellular stress response.