Cdc2 regulation for the meiotic transition from M phase to M phase

为了研究减数分裂周期中细胞周期从M期过渡到M期的调控机制，研究人员开发了一种执行M/M过渡的爪蟾卵母细胞提取物。使用减数分裂提取,我们发现一个低水平的Cdc2活动保持在减数分裂我的退出(MI),由于不完整的细胞周期蛋白降解原失活的残余Cdc2活动诱导进入S期和tyrosine-phosphorylation Cdc2 MI.Quantitative分析后表明,相当多的恰当地出席了MI退出和Cdc2抑制磷酸化在此期间被Cdc2的主导地位在良好的抑制。一致地，在提取物中添加超过临界量的Weel诱导Cdc2抑制磷酸化，将M/M转变为M/S/M转变。因此，在减数分裂M/M过渡期，Cdc2活性保留在MI出口是抑制进入S期所必需的。

To investigate the regulatory mechanisms for the cell cycle transition from M phase to M phase in meiotic cycles, a Xenopus oocyte extract that performs the M/M transition has been developed. Using the meiotic extract, we found that a low level of Cdc2 activity remained at the exit of meiosis I (MI), due to incomplete degradation of cyclin B.The inactivation of the residual Cdc2 activity induced both entry into S phase and tyrosine-phosphorylation on Cdc2 after MI.Quantitative analysis demonstrated that a considerable amount of Weel was present at the MI exit and Cdc2 inhibitory phosphorylation during this period was suppressed by the dominance of Cdc2 over Weel. Consistently, the addition of more than a critical amount of Weel to the extract induced Cdc2 inhibitory phosphorylation, changing the M/M transition into an M/S/M transition. Thus, the Cdc2 activity remaining at the MI exit is required for suppressing entry into S phase during the meiotic M/M transition period.