Deshaies R J
Division of Biology, California Institute of Technology, Pasadena California, 91125 USA.
Curr Opin Genet Dev. 1997 Feb;7(1):7-16. doi: 10.1016/s0959-437x(97)80103-7.
The budding yeast cell cycle oscillates between states of low and high cyclin B/cyclin-dependent kinase (CLB/CDK) activity. Remarkably, the two transitions that link these states are governed by ubiquitin-mediated proteolysis. The transition from low to high CLB activity is triggered by degradation of the CLB/CDK inhibitor SIC1, and the complementary excursion is propelled by the proteolytic destruction of CLBs. The extracellular environment controls this two-state circuit by regulating G1 cyclin/CDK activity, which is directly required for SIC1 proteolysis. Thus, stable oscillations of chromosome replication and segregation in budding yeast are propagated by the interplay between protein phosphorylation and protein degradation.
出芽酵母细胞周期在低和高细胞周期蛋白B/细胞周期蛋白依赖性激酶（CLB/CDK）活性状态之间振荡。值得注意的是，连接这些状态的两个转变由泛素介导的蛋白水解作用控制。CLB活性从低到高的转变由CLB/CDK抑制剂SIC1的降解触发，而互补的转变则由CLB的蛋白水解破坏推动。细胞外环境通过调节G1细胞周期蛋白/CDK活性来控制这个双态回路，而G1细胞周期蛋白/CDK活性是SIC1蛋白水解所直接需要的。因此，出芽酵母中染色体复制和分离的稳定振荡是由蛋白质磷酸化和蛋白质降解之间的相互作用传播的。
