Possible involvement of phototropins in leaf movement of kidney bean in response to blue light
Possible involvement of phototropins in leaf movement of kidney bean in response to blue light
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DOI：
10.1104/pp.105.062026
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发表时间：
2005-08-01
期刊：
影响因子：
7.4
通讯作者：
Shimazaki, K
中科院分区：
文献类型：
--
作者：
Inoue, S;Kinoshita, T;Shimazaki, K
菜豆的叶片在蓝光照射下会发生运动。这一运动是由受照射侧枕部运动细胞膨胀压力的降低引起的。在这项研究中，我们研究了运动的初始事件与运动的功能和质膜H+-ATPase在运动细胞中的作用。结果表明，在黑暗条件下，光敏素以去磷酸化状态存在，H+-ATPase以磷酸化状态存在。由14-3-3蛋白的结合行为决定，蓝光脉冲(30 S)可诱导光敏素的磷酸化和H+-ATPase的去磷酸化。促红细胞生成素的磷酸化迅速发生，随后H+-ATPase短暂的逐渐去磷酸化。当特异性黄素蛋白抑制剂二苯基碘、蛋白激酶抑制剂K-252a和星形孢子素作用于枕骨细胞时，细胞的趋光性磷酸化和H+-ATPase去磷酸化均被抑制。磷酸化和去磷酸化表现出与蓝光相似的注量率依赖关系。这些结果表明，趋光素可能通过去磷酸化作用作用于质膜H+-ATPase的上游，降低H+-ATPase的活性。我们提供了在枕骨运动细胞中存在三种趋光素的证据。
The leaf of kidney bean ( Phaseolus vulgaris) moves in response to blue light. The movement is induced by a decrease in the turgor pressure of pulvinar motor cells on the irradiated side. In this study, we investigated the initial event of the movement with respect to function of phototropin and the plasma membrane H+-ATPase in the motor cells. The results indicated that, in dark conditions, phototropin existed in a dephosphorylated state and the H+-ATPase existed in a phosphorylated state. A pulse of blue light ( 30 s) induced the phosphorylation of phototropin and the dephosphorylation of the H+-ATPase as determined by the binding behavior of 14-3-3 protein. Phototropin phosphorylation occurred rapidly, followed by the transient gradual dephosphorylation of the H+-ATPase. When the specific flavoprotein inhibitor diphenyleneiodonium and the protein kinase inhibitors K-252a and staurosporine were administered to pulvinar cells, both phototropin phosphorylation and H+-ATPase dephosphorylation were inhibited. The phosphorylation and dephosphorylation exhibited similar fluence rate dependencies to blue light. These results indicated that phototropin may function upstream of the plasma membrane H+-ATPase and decrease the activity of H+-ATPase by dephosphorylation. We provide evidence for the existence of three kinds of phototropins in pulvinar motor cells.