Oligomers of the Cdc7/Dbf4 protein kinase exist in the yeast cell.
Oligomers of the Cdc7/Dbf4 protein kinase exist in the yeast cell.
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Cdc7/Dbf4 蛋白激酶的寡聚物存在于酵母细胞中。
DOI：
10.1007/s004380050833
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
Sclafani,RA
中科院分区：
文献类型：
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作者：
Shellman,YG;Schauer,IE;Oshiro,G;Dohrmann,P;Sclafani,RA
Cdc7/Dbf4 蛋白激酶是酿酒酵母 DNA 复制启动所必需的。 Cdc7/Dbf4 蛋白激酶不是细胞周期蛋白依赖性激酶 (CDK)，但以类似的方式受到调节，因为在缺乏调节亚基 Dbf4 的情况下，Cdc7 激酶亚基处于失活状态。与已知的 CDK 相比，本报告显示 Cdc7/Dbf4 蛋白激酶是细胞中的寡聚物。支持这一说法的遗传数据包括几个 cdc7ts 等位基因和 cdc7T281A 等位基因之间的等位基因间互补，以及在 DNA 结合和反式激活结构域质粒中使用 Cdc7 双杂交系统的实验结果。通过使用与野生型 Cdc7 蛋白大小不同的 HA 标记的 Cdc7 蛋白显示了两种不同 Cdc7 分子之间的分子相互作用：抗 HA 抗体以大致相等的化学计量免疫沉淀这两种蛋白。对 Cdc7/Dbf4 蛋白激酶的天然分子量的分析与 Cdc7 蛋白的寡聚化一致，发现了约 180 和 300 kDa 的复合物。 Cdc7 蛋白寡聚物的存在可能是为了变构调节或允许多个底物蛋白分子磷酸化。
Cdc7/Dbf4 protein kinase is required for the initiation of DNA replication inSaccharomyces cerevisiae. Cdc7/Dbf4 protein kinase is not a cyclin-dependent kinase (CDK), but is regulated in a similar fashion in that the Cdc7 kinase subunit is inactive in the absence of the regulatory subunit Dbf4. In contrast to what is known about CDKs, Cdc7/Dbf4 protein kinase is shown to be an oligomer in the cell in this report. Genetic data that support this claim include interallelic complementation between severalcdc7ts alleles and thecdc7T281A allele and also the results of experiments using the two-hybrid system with Cdc7 in both DNA-binding and transactivation domain plasmids. A molecular interaction between two different Cdc7 molecules was shown by using a HA-tagged Cdc7 protein that differs in size from the wild-type Cdc7 protein: an anti-HA antibody immunoprecipitates both proteins in appproximately equal stoichiometry. Analysis of the native molecular weight of Cdc7/Dbf4 protein kinase is consistent with oligomerization of the Cdc7 protein in that complexes of about 180 and 300 kDa were found. Oligomers of Cdc7 protein may exist for the purpose of allosteric regulation or to allow phosphorylation of multiple substrate protein molecules.