MAPK target networks in Arabidopsis thaliana revealed using functional protein microarrays
MAPK target networks in Arabidopsis thaliana revealed using functional protein microarrays
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DOI：
10.1101/gad.1740009
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发表时间：
2009-01-01
影响因子：
10.5
通讯作者：
Dinesh-Kumar, Savithramma P.
中科院分区：
文献类型：
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作者：
Popescu, Sorina C.;Popescu, George V.;Dinesh-Kumar, Savithramma P.
通过促分裂原活化蛋白激酶（MPK）级联的信号传导是真核生物中复杂且基本的过程，需要MPK活化激酶（MKK）和MKK活化激酶（MKKK）。然而，迄今为止，只有有限数量的MKK-MPK相互作用和MPK磷酸化底物已被揭示。我们确定了哪些拟南芥MKKs在体内优先激活10种不同的MPKs，并使用激活的MPKs探测高密度蛋白质微阵列，以确定其磷酸化靶点。我们的分析揭示了已知的和新的信号传导模块，包括570 MPK磷酸化底物，这些底物富含参与调节发育，防御和应激反应的转录因子。通过植物内重构实验验证所选MPK底物。活化和野生型MKK的一个子集诱导细胞死亡，表明这些MKK在细胞死亡的调节中可能起作用。有趣的是，MKK 7和MKK 9诱导的死亡需要Sgt 1，一种已知的植物先天免疫过程中诱导细胞死亡的调节因子。我们预测的MKK-MPK磷酸化网络构成了了解MPK信号系统功能和特异性的宝贵资源。
Signaling through mitogen-activated protein kinases (MPKs) cascades is a complex and fundamental process in eukaryotes, requiring MPK-activating kinases (MKKs) and MKK-activating kinases (MKKKs). However, to date only a limited number of MKK-MPK interactions and MPK phosphorylation substrates have been revealed. We determined which Arabidopsis thaliana MKKs preferentially activate 10 different MPKs in vivo and used the activated MPKs to probe high-density protein microarrays to determine their phosphorylation targets. Our analyses revealed known and novel signaling modules encompassing 570 MPK phosphorylation substrates; these substrates were enriched in transcription factors involved in the regulation of development, defense, and stress responses. Selected MPK substrates were validated by in planta reconstitution experiments. A subset of activated and wild-type MKKs induced cell death, indicating a possible role for these MKKs in the regulation of cell death. Interestingly, MKK7- and MKK9-induced death requires Sgt1, a known regulator of cell death induced during plant innate immunity. Our predicted MKK-MPK phosphorylation network constitutes a valuable resource to understand the function and specificity of MPK signaling systems.