Cdc34 and the F-box protein Met30 are required for degradation of the Cdk-inhibitory kinase Swe1
Cdc34 and the F-box protein Met30 are required for degradation of the Cdk-inhibitory kinase Swe1
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DOI：
10.1101/gad.12.16.2587
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发表时间：
1998-08-15
影响因子：
10.5
通讯作者：
Reed, SI
中科院分区：
文献类型：
--
作者：
Kaiser, P;Sia, RAL;Reed, SI
泛素介导的蛋白水解控制着许多细胞周期调控蛋白的丰度。最近在酿酒酵母中的研究表明，由Cdc 53、Skp 1和第三种称为F-盒蛋白（称为SCF）的组分与Cdc 34结合组成的复合物特异性靶向降解调节蛋白，并且底物特异性可能由F-盒亚基介导。筛选与cdc 34突变的遗传相互作用产生了MET 30，其编码F盒蛋白。MET 30是细胞周期进展所需的必需基因，并且MET 30突变与SCF组分中的突变在遗传上相互作用。此外，Met 30，Cdc 53，Cdc 34和Skp 1在体内的物理相互作用提供了SCEMet 30复合物的证据。我们证明了Met 30参与Cdk抑制性激酶Swe 1的降解。Swe 1在Met 30突变体中是稳定的，并且GST-Met 30下拉实验揭示Met 30在体内特异性结合Swe 1。此外，从cdc 34或met 30突变体制备的提取物在Swe 1的多聚泛素化中是缺陷的。总之，这些数据表明，SCF介导的蛋白水解可能有助于调节进入有丝分裂。我们的数据，结合以前发表的结果，也提供了证据，不同的SCE复合物在体内和支持的想法，他们的F-盒亚基介导的SCE底物特异性。
Ubiquitin-mediated proteolysis controls the abundance of many cell cycle regulatory proteins. Recent work in Saccharomyces cerevisiae suggests that a complex consisting of Cdc53, Skp1, and a third component known as an F-box protein (termed SCF) in combination with Cdc34 specifically targets regulatory proteins for degradation, and that substrate specificity is likely to be mediated by the F-box subunit. A screen for genetic interactions with a cdc34 mutation yielded MET30, which encodes an F-box protein. MET30 is an essential gene required for cell cycle progression and met30 mutations interact genetically with mutations in SCF components. Furthermore, physical interactions between Met30, Cdc53, Cdc34, and Skp1 in vivo provide evidence for an SCEMet30 complex. We demonstrate the involvement of Met30 in the degradation of the Cdk-inhibitory kinase Swe1. Swe1 is stabilized in met30 mutants and GST-Met30 pull-down experiments reveal that Met30 specifically binds Swe1 in vivo. Furthermore, extracts prepared from cdc34 or met30 mutants are defective in polyubiquitination of Swe1. Taken together, these data suggest that SCF-mediated proteolysis may contribute to the regulation of entry into mitosis. Our data, in combination with previously published results, also provide evidence for distinct SCE complexes in vivo and support the idea that their F-box subunits mediate SCE substrate specificity.