Higashi H, Suzuki-Takahashi I, Taya Y, Segawa K, Nishimura S, Kitagawa M
Banyu Tsukuba Research Institute, Merck Research Laboratories, Japan.
Biochem Biophys Res Commun. 1995 Nov 13;216(2):520-5. doi: 10.1006/bbrc.1995.2653.
Cyclin-dependent kinase 2 (Cdk2), when bound to either cyclin A or cyclin E, recognizes the Ser/Thr-Pro-X-basic amino acid (motif A) as a phosphorylation site. In this study, we designed several peptides based on motif A and examined the substrate specificity of Cdk2-cyclin A and Cdk2-cyclin E using these peptides. Peptides containing a proline residue in the sequence Pro-X-Thr-Pro-X-basic amino acid (motif B) had higher affinity for both Cdk2 complexes than peptides containing motif A. Furthermore, differences in substrate affinity between the two Cdk2 complexes were caused by a proline residue adjacent to or three positions before the threonine residue. Similarly, the presence of different basic amino acids in motif B also had different effects on affinity for each complex. We demonstrate the possibility that the substrate specificity of Cdk2 bound to cyclin might be regulated by the species of cyclin.
细胞周期蛋白依赖性激酶2（Cdk2）与细胞周期蛋白A或细胞周期蛋白E结合时，将丝氨酸/苏氨酸-脯氨酸-X-碱性氨基酸（基序A）识别为磷酸化位点。在本研究中，我们基于基序A设计了几种肽，并使用这些肽研究了Cdk2-细胞周期蛋白A和Cdk2-细胞周期蛋白E的底物特异性。在序列脯氨酸-X-苏氨酸-脯氨酸-X-碱性氨基酸（基序B）中含有脯氨酸残基的肽对两种Cdk2复合物的亲和力都高于含有基序A的肽。此外，两种Cdk2复合物之间底物亲和力的差异是由苏氨酸残基相邻或其前三个位置的脯氨酸残基引起的。同样，基序B中不同碱性氨基酸的存在对每种复合物的亲和力也有不同影响。我们证明了与细胞周期蛋白结合的Cdk2的底物特异性可能受细胞周期蛋白种类调控的可能性。
