Large-Scale Arabidopsis Phosphoproteome Profiling Reveals Novel Chloroplast Kinase Substrates and Phosphorylation Networks
Large-Scale Arabidopsis Phosphoproteome Profiling Reveals Novel Chloroplast Kinase Substrates and Phosphorylation Networks
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DOI：
10.1104/pp.109.138677
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发表时间：
2009-06-01
期刊：
影响因子：
7.4
通讯作者：
Baginsky, Sacha
中科院分区：
文献类型：
--
作者：
Reiland, Sonja;Messerli, Gaelle;Baginsky, Sacha
我们的特点是磷酸化蛋白质组的拟南芥（拟南芥）幼苗使用高精度质谱仪和报告的1,429磷蛋白和3,029独特的磷酸肽的鉴定。其中174个为叶绿体磷蛋白。基序-X（基序提取器）分析叶绿体蛋白磷酸化位点，确定了四个显着丰富的激酶基序，其中包括酪蛋白激酶II（CKII）和脯氨酸定向激酶基序，以及两个新的基序在核糖体蛋白的羧基末端。使用的磷酸化基序作为一个足迹的一个特定的激酶类的活动，我们连接的磷蛋白与他们假定的激酶，并构建了一个叶绿体CKII磷酸化网络。网络拓扑结构表明，CKII是不同的叶绿体功能的中央调节器。为了深入了解蛋白质磷酸化的动态调节，我们分析了白天和夜晚结束时的磷酸化蛋白质组。结果表明，叶绿体激酶活性和磷酸化位点利用率只有微小的变化。一个值得注意的例外是ATP合酶β亚基，发现其在CKII磷酸化位点优先在黑暗中磷酸化。我们提出，ATP合酶的调节与14-3-3蛋白的CKII介导的磷酸化ATP合酶β亚基在黑暗中。
We have characterized the phosphoproteome of Arabidopsis (Arabidopsis thaliana) seedlings using high-accuracy mass spectrometry and report the identification of 1,429 phosphoproteins and 3,029 unique phosphopeptides. Among these, 174 proteins were chloroplast phosphoproteins. Motif-X (motif extractor) analysis of the phosphorylation sites in chloroplast proteins identified four significantly enriched kinase motifs, which include casein kinase II (CKII) and proline-directed kinase motifs, as well as two new motifs at the carboxyl terminus of ribosomal proteins. Using the phosphorylation motifs as a footprint for the activity of a specific kinase class, we connected the phosphoproteins with their putative kinases and constructed a chloroplast CKII phosphorylation network. The network topology suggests that CKII is a central regulator of different chloroplast functions. To provide insights into the dynamic regulation of protein phosphorylation, we analyzed the phosphoproteome at the end of day and end of night. The results revealed only minor changes in chloroplast kinase activities and phosphorylation site utilization. A notable exception was ATP synthase beta-subunit, which is found phosphorylated at CKII phosphorylation sites preferentially in the dark. We propose that ATP synthase is regulated in cooperation with 14-3-3 proteins by CKII-mediated phosphorylation of ATP synthase beta-subunit in the dark.