SKP1-SnRK protein kinase interactions mediate proteasomal binding of a plant SCF ubiquitin ligase
SKP1-SnRK protein kinase interactions mediate proteasomal binding of a plant SCF ubiquitin ligase
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DOI：
10.1093/emboj/20.11.2742
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发表时间：
2001-06-01
期刊：
影响因子：
11.4
通讯作者：
Koncz, C
中科院分区：
文献类型：
--
作者：
Farrás, R;Ferrando, A;Koncz, C
拟南芥Snf 1相关蛋白激酶（SnRKs）通过与激酶抑制剂PRL 1 WD蛋白的相互作用参与代谢、激素和应激反应的多效性调节。我们发现SKP 1/ASK 1是一个保守的SCF（（S）在bar下kp 1-cullin-（F）在bar -box下）泛素连接酶亚基，它抑制酵母中skp 1 -4的有丝分裂缺陷，与SnRKs的PRL 1结合C-末端结构域相互作用，相同的SnRK结构域募集SKP 1/ASK 1结合蛋白酶体蛋白，α 4/PAD 1，其在体外增强与SKP 1/ASK 1的三聚体SnRK复合物的形成。相反，PRL 1减少SKP 1/ASK 1与SnRKs的相互作用，SKP 1/ASK 1与cullin SCF亚基（AtCUL 1）和SnRK激酶共免疫沉淀，但不与来自拟南芥细胞提取物的PRL 1共免疫沉淀。SKP 1/ASK 1、cullin和蛋白酶体α亚基在分化的拟南芥细胞中显示核共定位，并且在细胞分裂期间与有丝分裂纺锤体和成膜体相关。在纯化的26 S蛋白酶体中检测到SnRK，并将表位标记的SKP 1/ASK 1与SnRK、cullin和蛋白酶体α-亚基共纯化，表明观察到的SnRK、SKP 1/ASK 1和α 4/PADD 1之间的蛋白质相互作用涉及拟南芥中SCF泛素连接酶的蛋白酶体f结合。
Arabidopsis Snf1-related protein kinases (SnRKs) are implicated in pleiotropic regulation of metabolic, hormonal and stress responses through their interaction with the kinase inhibitor PRL1 WD-protein. Here we show that SKP1/ASK1, a conserved SCF ((S) under bar kp1-cullin-(F) under bar -box) ubiquitin ligase subunit, which suppresses the skp1-4 mitotic defect in yeast, interacts with the PRL1-binding C-terminal domains of SnRKs, The same SnRK domains recruit an SKP1/ASK1-binding proteasomal protein, alpha4/PAD1, which enhances the formation of a trimeric SnRK complex with SKP1/ASK1 in vitro. By contrast, PRL1 reduces the interaction of SKP1/ASK1 with SnRKs, SKP1/ASK1 is co-immunoprecipitated with a cullin SCF subunit (AtCUL1) and an SnRK kinase, but not with PRL1 from Arabidopsis cell extracts. SKP1/ASK1, cullin and proteasomal alpha -subunits show nuclear co-localization in differentiated Arabidopsis cells, and are observed in association with mitotic spindles and phragmoplasts during cell division. Detection of SnRK in purified 26S proteasomes and co-purification of epitope-tagged SKP1/ASK1 with SnRK, cullin and proteasomal a-subunits indicate that the observed protein interactions between SnRK, SKP1/ASK1 and alpha4/PADD1 are involved in proteasomaf binding of an SCF ubiquitin ligase in Arabidopsis.