Heinrich-Heine Universität Düsseldorf, Biochemische Pflanzenphysiologie, Düsseldorf, Germany.
Plant Signal Behav. 2011 Jan;6(1):164-6. doi: 10.4161/psb.6.1.14034. Epub 2011 Jan 1.
The membrane protein ETHYLENE INSENSITIVE2 (EIN2), which is supposed to act between the soluble serine/threonine kinase CTR1 and the EIN3/EIL family of transcription factors, is a central and most critical element of the ethylene signaling pathway in Arabidopsis. In a recent study, we have identified that EIN2 interacts tightly with all members of the Arabidopsis ethylene receptor family - proteins that mark the starting point of the signaling pathway. Our studies show consistently that the kinase domain of the receptors is essential for the formation of the EIN2-receptor complex. Furthermore, mutational analysis demonstrates that phosphorylation is a key mechanism in controlling the interaction of EIN2 and the ethylene receptors. Interaction studies in the presence of the ethylene agonist cyanide revealed a causal link between hormone binding and complex formation. In the presence of the plant hormone agonist the auto-kinase activity of the receptors is inhibited and the non-phosphorylated kinase domain of the receptors binds tightly to the carboxyl-terminal domain of EIN2. In the absence of cyanide inhibition of the auto-kinase activity is relieved and complex formation with the phosphorylated kinase domain of the receptors is reduced. Our data suggest a novel model on the integration of EIN2 in the ethylene signaling pathway.
膜蛋白 ETHYLENE INSENSITIVE2（EIN2）被认为在可溶性丝氨酸/苏氨酸激酶 CTR1 和 EIN3/EIL 转录因子家族之间发挥作用，是拟南芥中乙烯信号通路的核心和最关键的要素。在最近的一项研究中，我们已经确定 EIN2 与拟南芥所有乙烯受体家族成员紧密相互作用-这些蛋白标记着信号通路的起点。我们的研究一致表明，受体的激酶结构域对于 EIN2-受体复合物的形成至关重要。此外，突变分析表明，磷酸化是控制 EIN2 和乙烯受体相互作用的关键机制。在存在乙烯激动剂氰化物的情况下进行的相互作用研究揭示了激素结合和复合物形成之间的因果关系。在植物激素激动剂存在下，受体的自动激酶活性受到抑制，并且非磷酸化的激酶结构域受体与 EIN2 的羧基末端结构域紧密结合。在没有氰化物抑制的情况下，自动激酶活性得到缓解，并且与受体的磷酸化激酶结构域的复合物形成减少。我们的数据提出了一个关于 EIN2 整合到乙烯信号通路的新模型。
