Holmes J K, Solomon M J
Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520-8024, USA.
J Biol Chem. 1996 Oct 11;271(41):25240-6. doi: 10.1074/jbc.271.41.25240.
Protein phosphorylation by members of the Cdk (cyclin-dependent kinase) family of protein kinases is necessary for progression through the cell cycle. However, the primary sequence determinants of Cdk substrate specificity have yet to be examined quantitatively. We have used a panel of glutathione S-transferase peptide fusions to investigate the fine-structure specificity of p33(cdk2) and p34(cdc2). Our data indicate that the generally held consensus sequences for p34(cdc2) represent a significant oversimplification of its true specificity and that this specificity is conserved between species. p33(cdk2) and p34(cdc2) have similar but distinct substrate specificities that are affected modestly by the associated cyclin subunit. We derive specific values of phosphorylation efficiencies by these enzymes that can be used to estimate the phosphorylation potential of proposed Cdk substrates.
细胞周期蛋白依赖性激酶（Cdk）家族的蛋白激酶成员对蛋白质进行磷酸化，这是细胞周期进程所必需的。然而，Cdk底物特异性的一级序列决定因素尚未得到定量研究。我们使用了一组谷胱甘肽S-转移酶肽融合体来研究p33（cdk2）和p34（cdc2）的精细结构特异性。我们的数据表明，通常认为的p34（cdc2）共有序列极大地简化了其真正的特异性，并且这种特异性在物种间是保守的。p33（cdk2）和p34（cdc2）具有相似但不同的底物特异性，相关的细胞周期蛋白亚基对其有适度影响。我们得出了这些酶的磷酸化效率的具体值，可用于估计所提出的Cdk底物的磷酸化潜力。
