Phosphorylation site specificity of the CDC2-related kinase PITALRE.
Phosphorylation site specificity of the CDC2-related kinase PITALRE.
复制标题
CDC2 相关激酶 PITALRE 的磷酸化位点特异性。
DOI：
10.1042/bj3200983
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Graña,X
中科院分区：
文献类型：
--
作者：
Garriga,J;Segura,E;Mayol,X;Grubmeyer,C;Graña,X
PITALRE是属于细胞分裂周期2（CDC 2）激酶家族的人蛋白激酶，并且是含有几种细胞蛋白的多聚体复合物的催化亚基。来自几种细胞系和组织的PITALRE复合物磷酸化视网膜母细胞瘤蛋白和髓鞘碱性蛋白（MBP）。在目前的工作中，我们已经发现，MBP是磷酸化的PITALRE复合物的丝氨酸和苏氨酸残基。两种不同的抗体提出了PITALRE纯化几乎相同的激酶活性，MBP磷酸肽图谱和磷酸氨基酸分析。我们已经确定了脯氨酸指导的残基Ser-162 MBP作为一个主要的PITALRE磷酸化位点。此外，我们的研究结果表明，两个MBP脯氨酸指导的苏氨酸残基，Thr-97，也选择性磷酸化的PITALRE。这些数据，连同来自MBP上被PITALRE磷酸化的位点的不同肽底物的分析，表明PITALRE是Ser/Thr脯氨酸导向的激酶。此外，我们的研究结果表明，PITALRE具有底物位点特异性，可与CDC 2和细胞周期蛋白依赖性激酶2（CDK 2）的底物位点特异性区分开来。
PITALRE is a human protein kinase belonging to the cell division cycle 2 (CDC2) kinase family, and is the catalytic subunit of a multimeric complex that contains several cellular proteins. PITALRE complexes from several cell lines and tissues phosphorylate retinoblastoma protein and myelin basic protein (MBP). In the present work, we have found that MBP is phosphorylated by PITALRE complexes on both Ser and Thr residues. Two different antibodies raised to PITALRE purified virtually identical kinase activities, as analysed by MBP phosphopeptide mapping and phosphoamino acid analysis. We have identified the proline-directed residue Ser-162 of MBP as a major phosphorylation site for PITALRE. In addition, our results suggest that one of the two MBP proline-directed threonine residues, Thr-97, is also selectively phosphorylated by PITALRE. These data, together with analysis of different peptide substrates derived from sites on MBP that are phosphorylated by PITALRE, indicate that PITALRE is a Ser/Thr proline-directed kinase. In addition, our results show that PITALRE has a substrate site specificity distinguishable from those of the CDC2 and cyclin-dependent kinase 2 (CDK2).