In vitro reconstitution of an abscisic acid signalling pathway.
In vitro reconstitution of an abscisic acid signalling pathway.
复制标题
作者：
植物激素脱落酸 (ABA) 调节植物中许多基因的表达，在抗逆性、生长发育中发挥着关键作用。据报道，几种蛋白质具有 ABA 受体的功能，还有更多蛋白质参与 ABA 信号传导。然而，ABA 受体的身份仍然存在争议，从感知到下游基因表达的信号传导机制尚不清楚。在这里，我们表明，通过将最近鉴定的 ABA 受体 PYR1 与蛋白磷酸酶 2C ABI1、丝氨酸/苏氨酸蛋白激酶 SnRK2.6/OST1 和转录因子 ABF2/AREB1 相结合，我们可以在体外重建 ABA 触发的转录因子磷酸化。将这四种成分引入植物原生质体会导致 ABA 响应基因表达。原生质体和试管重建测定用于测试受体、蛋白磷酸酶和激酶家族的各个成员的功能。我们的结果表明，SnRK2 激酶的默认状态是自磷酸化、活性状态，并且 PP2C 通过物理相互作用和去磷酸化使 SnRK2 激酶保持非活性状态。我们发现，在 ABA 存在的情况下，PYR/PYL 受体蛋白可以破坏 SnRK2 和 PP2C 之间的相互作用，从而阻止 PP2C 介导的 SnRK2 去磷酸化，并导致 SnRK2 激酶的激活。我们的结果揭示了对 ABA 信号传导机制的新见解，并定义了完整的主要 ABA 信号传导途径的最小核心组件集。
The phytohormone abscisic acid (ABA) regulates the expression of many genes in plants and plays critical roles in stress resistance, and growth and development. Several proteins have been reported to function as ABA receptors and many more are known to be involved in ABA signaling. However, the identities of ABA receptors remain controversial and the mechanism of signaling from perception to downstream gene expression is unclear. Here we show that by combining the recently identified ABA receptor PYR1, with the protein phosphatase 2C ABI1, the serine/threonine protein kinase SnRK2.6/OST1, and the transcription factor ABF2/AREB1, we can reconstitute ABA-triggered phosphorylation of the transcription factor in vitro. Introduction of these four components into plant protoplasts results in ABA-responsive gene expression. The protoplast and test tube reconstitution assays were used to test the function of various members of the receptor, protein phosphatase, and kinase families. Our results suggest that the default state of the SnRK2 kinases is an autophosphorylated, active state and that the SnRK2 kinases are kept inactive by the PP2Cs through physical interaction and dephosphorylation. We found that in the presence of ABA, the PYR/PYL receptor proteins can disrupt the interaction between the SnRK2s and PP2Cs, thus preventing the PP2Cs-mediated dephosphorylation of the SnRK2s and resulting in the activation of the SnRK2 kinases. Our results reveal new insights into ABA signaling mechanisms and define a minimal set of core components of a complete major ABA signaling pathway.
登录
查看更多内容
DOI：
10.1126/science.1173041
发表时间：
2009-05-22
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Park SY;Fung P;Nishimura N;Jensen DR;Fujii H;Zhao Y;Lumba S;Santiago J;Rodrigues A;Chow TF;Alfred SE;Bonetta D;Finkelstein R;Provart NJ;Desveaux D;Rodriguez PL;McCourt P;Zhu JK;Schroeder JI;Volkman BF;Cutler SR
通讯作者：
Cutler SR
影响因子：
64.5
作者：
Nemhauser, Jennifer L.;Hong, Fangxin;Chory, Joanne
通讯作者：
Chory, Joanne
DOI：
10.1073/pnas.0505667103
发表时间：
2006-02-07
影响因子：
11.1
作者：
Furihata, T;Maruyama, K;Yamaguchi-Shinozaki, K
通讯作者：
Yamaguchi-Shinozaki, K
影响因子：
7.4
作者：
Belin, Christophe;de Franco, Pierre-Olivier;Thomine, Sebastien
通讯作者：
Thomine, Sebastien
影响因子：
64.8
作者：
Shen, Yuan-Yue;Wang, Xiao-Fang;Zhang, Da-Peng
通讯作者：
Zhang, Da-Peng