Phosphorylation of plasma membrane aquaporin regulates temperature-dependent opening of tulip petals
Phosphorylation of plasma membrane aquaporin regulates temperature-dependent opening of tulip petals
复制标题
DOI：
10.1093/pcp/pch069
复制
发表时间：
2004-01-01
影响因子：
4.9
通讯作者：
Shibata, H
中科院分区：
文献类型：
--
作者：
Azad, AK;Sawa, Y;Shibata, H
郁金香花瓣的开放和闭合在黑暗中通过改变温度从5 ℃到20 ℃进行开放和20 ℃到5 ℃进行闭合来再现。开放过程伴随着（H2O）-H-3运输通过茎从培养介质的花瓣。Ca（2+）通道阻断剂和Ca（2+）螯合剂抑制花瓣开放和（H2O）-H-3转运。分离的质膜部分中的几种蛋白质在20 ℃下在25 μ M Ca 2+存在下被磷酸化。磷酸化的31-kDa蛋白质在免疫学上被认为是推定的质膜水通道蛋白（PM-AQP）。这种磷酸化的PM-AQP清楚地与抗磷酸丝氨酸反应。凝胶内分析显示，在分离的质膜中存在45-kDa的Ca 2+依赖性蛋白激酶。推测的PM-AQP的磷酸化被认为激活由PM-AQP组成的水通道。在5 ℃下花瓣关闭期间也观察到磷酸化的PM-AQP的去磷酸化，这表明水通道失活。
The opening and closing of tulip petals was reproduced in the dark by changing the temperature from 5 degreesC to 20 degreesC for opening and 20 degreesC to 5 degreesC for closing. The opening process was accompanied by (H2O)-H-3 transport through the stem from the incubation medium to the petals. A Ca(2+)channel blocker and a Ca2+-chelator inhibited petal opening and (H2O)-H-3 transport. Several proteins in the isolated plasma membrane fraction were phosphorylated in the presence of 25 muM Ca2+ at 20 degreesC. The 31-kDa protein that was phosphorylated, was suggested immunologically as the putative plasma membrane aquaporin (PM-AQP). This phosphorylated PM-AQP clearly reacted with the anti-phospho-Ser. In-gel assay revealed the presence of a 45-kDa Ca2+-dependent protein kinase in the isolated plasma membrane. Phosphorylation of the putative PM-AQP was thought to activate the water channel composed of PM-AQP Dephosphorylation of the phosphorylated PM-AQP was also observed during petal closing at 5 degreesC, suggesting the inactivation of the water channel.