COI1 links jasmonate signalling and fertility to the SCF ubiquitin-ligase complex in Arabidopsis
COI1 links jasmonate signalling and fertility to the SCF ubiquitin-ligase complex in Arabidopsis
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DOI：
10.1046/j.1365-313x.2002.01432.x
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发表时间：
2002-11-01
期刊：
影响因子：
7.2
通讯作者：
Turner, JG
中科院分区：
文献类型：
--
作者：
Devoto, A;Nieto-Rostro, M;Turner, JG
茉莉酸盐（JAs）调节拟南芥（Arabidopsis thaliana）的伤口和防御反应、花粉发育和应激相关的生长抑制。值得注意的是，这些反应都需要COI1，一种F-box蛋白。其他F-box蛋白与SKP1和cullin蛋白相互作用形成SCF复合物，选择性地招募泛素化靶向调节蛋白。为了确定COI1是否也在SCF复合体中起作用，我们对与COI1结合的拟南芥蛋白进行了表征。在酵母中筛选了一个拟南芥cDNA表达文库，用于克隆可与COI1结合的蛋白。我们找到了两个SKP1同源物和一个组蛋白去乙酰化酶。拟南芥F-box蛋白TIR1与SKP1蛋白相互作用，但不与组蛋白去乙酰化酶相互作用。突变的COI1蛋白表明，F-box是与skp1相互作用所必需的，但与组蛋白去乙酰化酶相互作用所需的序列是富含亮氨酸的重复结构域。将表位标记的COI1引入拟南芥植株和细胞培养中。共免疫沉淀实验证实了COI1在植物中与skp1样蛋白和组蛋白去乙酰化酶相互作用，也表明COI1与cullin相互作用。这些结果表明COI1在体内可形成SCF COI1复合物。因此，COI1有望在植物中形成一个功能性的e3型泛素连接酶，并可能通过靶向泛素化组蛋白去乙酰化酶来调节茉莉酸反应基因的表达。
Jasmonates (JAs) regulate Arabidopsis thaliana wound and defence responses, pollen development, and stress-related growth inhibition. Significantly, each of these responses requires COI1, an F-box protein. Other F-box proteins interact with SKP1 and cullin proteins to form SCF complexes that selectively recruit regulatory proteins targeted for ubiquitination. To determine whether COI1 also functions in an SCF complex, we have characterized Arabidopsis proteins that bind to COI1. An Arabidopsis cDNA expression library was screened in yeast for clones that produce proteins which can bind to COI1. We recovered two SKP1 homologues and a histone deacetylase. The Arabidopsis F-box protein TIR1 interacted with SKP1 proteins, but not with the histone deacetylase. Mutant COI1 proteins revealed that the F-box is required for interaction with SKP1s, but that sequences in leucine-rich repeat domains are required for interaction with the histone deacetylase. Epitope-tagged COI1 was introduced into Arabidopsis plants and cell cultures. Co-immunoprecipitation experiments confirmed the interaction in planta of COI1 with SKP1-like proteins and histone deacetylase, and also indicated that COI1 interacted with cullin. These results suggest that COI1 forms an SCF COI1 complex in vivo. COI1 is therefore expected to form a functional E3-type ubiquitin ligase in plants and to regulate expression of jasmonate responsive genes, possibly by targeted ubiquitination of a histone deacetylase.