The CDC7 protein of Saccharomyces cerevisiae is a phosphoprotein that contains protein kinase activity.
The CDC7 protein of Saccharomyces cerevisiae is a phosphoprotein that contains protein kinase activity.
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酿酒酵母的CDC7蛋白是一种含有蛋白激酶活性的磷蛋白。
DOI：
10.1073/pnas.88.9.3574
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发表时间：
1991
影响因子：
11.1
通讯作者：
J. Campbell
中科院分区：
文献类型：
--
作者：
H. Yoon;J. Campbell
酿酒酵母的CDC 7蛋白可能参与G1/S-相转变和/或有丝分裂DNA合成的起始。CDC 7基因具有两个框内AUG密码子作为可能的翻译起始位点，其将分别产生58-和56-kDa蛋白质。来自重组质粒的p58和p56都补充了cdc 7 -1等位基因的温度敏感性生长缺陷。为了确定CDC 7蛋白的生化功能，克隆了CDC 7基因，并制备了针对CDC 7蛋白的多克隆抗体。用这些抗体从酵母制备的CDC 7免疫复合物磷酸化组蛋白H1。激酶活性在携带cdc 7 -1温度敏感突变等位基因的菌株中是热不稳定的，并且在携带过表达p56或p58的质粒的菌株中升高超过10倍，证实免疫沉淀物中的激酶是CDC 7基因产物。此外，我们表明，CDC 7是一个磷蛋白本身。间接免疫荧光和生化分级显示，CDC 7蛋白是目前在细胞核中的相对较高的浓度相比，细胞质，这表明核蛋白可能是底物的CDC 7蛋白。
The CDC7 protein of Saccharomyces cerevisiae may be involved in the G1/S-phase transition and/or in the initiation of mitotic DNA synthesis. The CDC7 gene has two in-frame AUG codons as possible translation start sites, which would produce 58- and 56-kDa proteins, respectively. Both p58 and p56 derived from recombinant plasmids complement the temperature-sensitive growth defect of the cdc7-1 allele. To determine the biochemical function of the CDC7 protein, the CDC7 gene was cloned and polyclonal antibodies were produced against the CDC7 protein. CDC7 immune complexes prepared from yeast with these antibodies phosphorylate histone H1. Kinase activity is thermolabile in strains carrying the cdc7-1 temperature-sensitive mutant allele and is elevated greater than 10-fold in strains carrying plasmids overexpressing either p56 or p58, confirming that the kinase in the immunoprecipitates is the CDC7 gene product. In addition, we show that CDC7 is a phosphoprotein itself. Indirect immunofluorescence and biochemical fractionation show that the CDC7 protein is present at relatively high concentrations in the nucleus compared with the cytoplasm, suggesting that nuclear proteins may be substrates for the CDC7 protein.