Mutations of the CK2 phosphorylation site of Sic1 affect cell size and S-Cdk kinase activity in Saccharomyces cerevisiae
Mutations of the CK2 phosphorylation site of Sic1 affect cell size and S-Cdk kinase activity in Saccharomyces cerevisiae
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DOI：
10.1046/j.1365-2958.2003.03836.x
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发表时间：
2004-01-01
影响因子：
3.6
通讯作者：
Alberghina, L
中科院分区：
文献类型：
--
作者：
Coccetti, P;Rossi, RL;Alberghina, L
通过序列分析，我们发现了一个以丝氨酸（201）为中心的氨基酸序列，该序列与Sic 1的C-末端抑制结构域内的严格CK 2共有位点相匹配。在这里，我们通过直接质谱分析表明，Sic 1，而不是一个突变的蛋白质，其CK 2磷酸受体位点已突变为丙氨酸，Sic 1（S201 A），实际上是磷酸化的丝氨酸201在体外由CK 2。丝氨酸201的突变改变了生长和细胞周期进程之间的协调。平均蛋白质含量和DNA合成开始时的平均蛋白质含量的显着增加被观察到的指数生长的细胞窝藏的Sic 1（S201 A）蛋白。在携带Sic 1（S201 E）的细胞中观察到相同参数的强烈降低。在S-Cdk活性水平上，细胞大小和细胞周期之间的失调协调也是明显的。
By sequence analysis we found an amino acid stretch centred on Serine(201) matching a stringent CK2 consensus site within the C-terminal, inhibitory domain of Sic1. Here we show by direct mass spectrometry analysis that Sic1, but not a mutant protein whose CK2 phospho-acceptor site has been mutated to alanine, Sic1(S201A), is actually phosphorylated in vitro by CK2 on Serine 201. Mutation of Serine 201 alters the coordination between growth and cell cycle progression. A significant increase of average protein content and of the average protein content at the onset of DNA synthesis is observed for exponentially growing cells harbouring the Sic1(S201A) protein. A strong reduction of the same parameters is observed in cells harbouring Sic1(S201E). The deregulated coordination between cell size and cell cycle is also apparent at the level of S-Cdk activity.