Two F-box/WD-repeat proteins Pop1 and Pop2 form hetero- and homo-complexes together with cullin-1 in the fission yeast SCF (Skp1-Cullin-1-F-box) ubiquitin ligase
Two F-box/WD-repeat proteins Pop1 and Pop2 form hetero- and homo-complexes together with cullin-1 in the fission yeast SCF (Skp1-Cullin-1-F-box) ubiquitin ligase
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DOI：
10.1046/j.1365-2443.1998.00225.x
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发表时间：
1998-11-01
期刊：
影响因子：
2.1
通讯作者：
Toda, T
中科院分区：
文献类型：
--
作者：
Kominami, K;Ochotorena, I;Toda, T
背景：在泛素依赖性蛋白水解途径中，泛素连接酶（E3）负责底物选择性和降解时间。一个新的E3， SCF （Skp1-Cullin-1/Cdc53-F-box）在细胞周期进程中起关键作用。在裂变酵母中，F-box/WD-repeat蛋白Pop1调控细胞周期蛋白依赖性激酶（cyclin-dependent kinase， cyclin-依赖性激酶）抑制剂Rum1和S期调节因子Cdc18的水平。结果：我们克隆并鉴定了编码Pop1相关的F-box/WD-repeat蛋白的pop2（+）基因。Pop2与Pop1在Rum1和Cdc18的降解中起重叠作用，但这两种蛋白不是功能上的同源物，Pop1和Pop2在细胞中形成异质二聚体和同源二聚体。我们分析了两个裂变酵母cullin成员，发现cullin-1作为scfpop1,2的组成部分起作用，而cullin-3则参与不同的应激反应途径。结论：裂变酵母SCF由两种结构相关但功能独立的F-box/WD-repeat蛋白Pop1和Pop2组成，通过形成SCFPop1/Pop1、SCFPop1/Pop2和SCFPop2/Pop2三种不同的复合物，SCF进化出了一种复杂的机制来控制Rum1和Cdc18的水平，裂变酵母SCF还含有cullin-1作为一个普遍的支架，每个cullin成员都有不同的生物学作用。
Background: In the ubiquitin-dependent proteolysis pathway, a ubiquitin ligase (E3) is responsible for substrate selectivity and timing of degradation. A novel E3, SCF (Skp1-Cullin-1/Cdc53-F-box) plays a pivotal role in cell cycle progression. In fission yeast, F-box/WD-repeat protein Pop1 regulates the level of the CDK (cyclin-dependent kinase) inhibitor Rum1 and the S phase regulator Cdc18,Results: We have cloned and characterized the pop2(+) gene which encodes the Pop1-related F-box/WD-repeat protein. Pop2 plays a role which overlaps with Pop1 in the degradation of Rum1 and Cdc18, However, these two proteins are not functional homologues, Pop1 and Pop2 form hetero- as well as homo-dimers in the cell. We have analysed two fission yeast cullin members and found that cullin-1 functions as a component of SCFPop1,2, whilst cullin-3 is involved in the distinct stress-response pathway.Conclusions: Fission yeast SCF is composed of Pop1 and Pop2, two structurally related but functionally independent F-box/WD-repeat proteins, By forming three distinct complexes, SCFPop1/Pop1, SCFPop1/Pop2 and SCFPop2/Pop2, SCF has evolved a sophisticated mechanism to control the level of Rum1 and Cdc18, Fission yeast SCF also contains cullin-1 as a universal scaffold and each cullin member plays a distinct biological role.