Rapid accumulation of phosphatidylinositol 4,5-bisphosphate and inositol 1,4,5-trisphosphate correlates with calcium mobilization in salt-stressed Arabidopsis
Rapid accumulation of phosphatidylinositol 4,5-bisphosphate and inositol 1,4,5-trisphosphate correlates with calcium mobilization in salt-stressed Arabidopsis
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DOI：
10.1104/pp.126.2.759
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发表时间：
2001-06-01
期刊：
影响因子：
7.4
通讯作者：
Hama, H
中科院分区：
文献类型：
--
作者：
DeWald, DB;Torabinejad, J;Hama, H
磷酸肌醇磷脂酰肌醇4，5-二磷酸[PtdIns（4，5）P-2]是动物细胞中的关键信号分子。在动物体内可水解产生1，2-二酰甘油和1，4，5-三磷酸肌醇（IP）。细胞分别导致蛋白激酶C活化和细胞钙动员。除了其在蛋白质的组成性和调节性分泌中的关键作用外，PtdIns（4，5）P-2与修饰细胞骨架结构和磷脂成分的蛋白质结合。在此，我们报告，拟南芥植物生长在液体培养基中迅速增加PtdIns（4，5）P-2的合成，在处理与氯化钠，氯化钾，山梨醇。这些结果表明，当受到盐度和渗透胁迫的挑战时，陆生植物的反应不同于积累不同种类磷酸肌醇的藻类、酵母和动物细胞。我们还显示了数据表明，整株IP 3水平显着增加1分钟内的压力开始，IP 3水平继续增加超过30分钟，在应力应用。此外，使用钙指示剂Fura-2和Flue-3，我们表明，根细胞内钙浓度增加，响应于应力处理。综上所述，这些结果表明，在响应盐和渗透胁迫，拟南芥使用的信号转导途径，其中一个小的，但重要的部分PtdIns（4，5）P-2水解为IP 3。这些数据还表明，响应于盐和渗透胁迫而合成的大多数PtdIns（4，5）P-2可用于不同于经典IP 3信号传导途径的细胞信号传导事件。
The phosphoinositide phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P-2] is a key signaling molecule in animal cells. It can be hydrolyzed to release 1,2-diacyglycerol and inositol 1,4,5-trisphosphate (IP,), which in animal. cells lead to protein kinase C activation and cellular calcium mobilization, respectively, in addition to its critical roles in constitutive and regulated secretion of proteins, PtdIns(4,5)P-2 binds to proteins that modify cytoskeletal architecture and phospholipid constituents. Herein, we report that Arabidopsis plants grown in liquid media rapidly increase PtdIns(4,5)P-2 synthesis in response to treatment with sodium chloride, potassium chloride, and sorbitol. These results demonstrate that when challenged with salinity and osmotic stress, terrestrial plants respond differently than algae, yeasts, and animal cells that accumulate different species of phosphoinositides. We also show data demonstrating that whole-plant IP3 levels increase significantly within 1 min of stress initiation, and that IP3 levels continue to increase for more than 30 min during stress application. Furthermore, using the calcium indicators Fura-2 and Flue-3 we show that root intracellular calcium concentrations increase in response to stress treatments. Taken together, these results suggest that in response to salt and osmotic stress, Arabidopsis uses a signaling pathway in which a small but significant portion of PtdIns(4,5)P-2 is hydrolyzed to IP3. The accumulation of IP3 occurs during a time frame similar to that observed for stress induced calcium mobilization These data also suggest that the majority of the PtdIns(4,5)P-2 synthesized in response to salt and osmotic stress may be utilized for cellular signaling events distinct from the canonical IP3 signaling pathway.