ik3-1/Cables is a substrate for cyclin-dependent kinase 3 (cdk 3)
ik3-1/Cables is a substrate for cyclin-dependent kinase 3 (cdk 3)
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DOI：
10.1046/j.0014-2956.2001.02555.x
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发表时间：
2001-12-01
期刊：
影响因子：
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通讯作者：
Matsuoka, M
中科院分区：
文献类型：
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作者：
Yamochi, T;Semba, K;Matsuoka, M
P70(ik3-1)(一个70 kDa的蛋白质)含有一个周期蛋白盒，并在体内和体外与p35(Cdk3)结合[Matsuoka，M.，Matsuura，Y.，Semba，K.&Nishimoto，I.(2000)Biochem]。生物群落。[中英文摘要]Re.Commun.273,442-447]。尽管p70(ik3-1)在结构上与细胞周期蛋白相似，但p70(ik3-1)不能激活细胞周期蛋白依赖性蛋白激酶3(Cdk3)介导的pRb、组蛋白H1或RNA聚合酶II的C末端结构域的磷酸化。我们还发现，在细胞周期蛋白E和edk3异位过表达的COS7细胞中，共表达的p70(ik3-1)中Ser274的磷酸化水平上调。因此，我们认为p70(ik3-1)是cdk3介导的磷酸化的底物。
p70(ik3-1) (a 70-kDa protein) contains a cyclin box, and binds to p35(cdk3) in vivo and in vitro [Matsuoka, M., Matsuura, Y., Semba, K. & Nishimoto, I. (2000) Biochem. Biophys. Res. Commun. 273, 442-447]. In spite of its structural similarity to cyclins, p70(ik3-1) does not activate cyclin-dependent kinase 3 (cdk3)-mediated phosphorylation of pRb, histone H1, or the C-terminal domain of RNA polymerase II. Here, we report that Ser274 of p70(ik3-1) is phosphorylated by cdk2 or cdk3 bound to cyclin A and to cyclin E in vitro. We also found that in COS7 cells in which cyclin E and edk3 were ectopically overexpressed, the phosphorylation level of Ser274 in coexpressed p70(ik3-1) is upregulated. We therefore conclude that p70(ik3-1) is a substrate for cdk3-mediated phosphorylation.