Conversion from APC/C:Cdc20 to APC/C:Cdh1 in late anaphase

The activity of the APC/C must be appropriately regulated during the cell cycle to ensure the timely degradation of its substrates. Of particular importance is the conversion from APC/C:Cdc20 to APC/C:Cdh1 in late anaphase. Phosphorylation of both the APC/C complex and Cdh1 regulate this conversion. During mitosis, several APC/C subunits are phosphorylated increasing the activity of APC/C:Cdc20. However, phosphorylation of Cdh1 by mitotic Cyclin:Cdk complexes prevents it from activating the APC/C. Dephosphorylation of Cdh1 in late anaphase by Cdc14a results in the activation of APC/C:Cdh1 (reviewed in Castro et al, 2005).

在细胞周期过程中，APC/C（细胞周期蛋白依赖性激酶）的活性必须得到适当的调控，以确保其底物的及时降解。在后期有丝分裂阶段，APC/C:Cdc20向APC/C:Cdh1的转化尤为重要。APC/C复合体及其组分Cdh1的磷酸化调控这一转化过程。在有丝分裂期间，APC/C的多个亚基被磷酸化，从而增强APC/C:Cdc20的活性。然而，由有丝分裂周期蛋白:Cdk复合体对Cdh1的磷酸化阻止了其激活APC/C。在后期有丝分裂阶段，由Cdc14a介导的Cdh1去磷酸化导致APC/C:Cdh1的激活（参见Castro等人，2005年的综述）。