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SET8是现今发现唯一能够特异性单甲基化组蛋白 H4第20位赖氨酸（H4K20）的赖氨酸甲基转移酶。单甲基化 H4K20和 SET8的含量在细胞周期的不同时相中发生动态变化，这种动态变化调节了细胞周期的进程。在 G1／S 过渡期 SET8通过泛素 E3连接酶 SCF ／skp2复合物泛素化而降解。 SET8和单甲基化 H4K20在 S 期处于低表达，这与 E3泛素连接酶复合物 CRL4 cdt2高活性有关。SET8和单甲基化 H4K20的表达在 G2／M 期达到高峰。主要是由于 SET8的 S29磷酸化抑制了 SET8的降解。 SET8的异常表达会导致细胞周期阻滞。“,”SET8 is the sole enzyme known to specially catalyze monomethylation of histone H4 lysine 20.The level of H4K20me1 and SET8 are dynamically changed in different stages of cell cycle,which regu-lates the cell cycle processing.At G1 /S transition,SET8 is degraded through ubiquitination via SCF /skp2 complex.During S phase,the low level of SET8 and H4K20me1 is related to high activity of CRL4cdt2.The level of SET8 and H4K20me1 reach peak during G2 /M phase, because phosphorylation of S29 of SET8 inhibits the degradation of SET8.The abnormal expression of SET8 can result in the cell cycle arrest.