Heim Andreas, Rymarczyk Beata, Mayer Thomas U
Department of Biology and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstr. 10, 78457, Konstanz, Germany.
Adv Exp Med Biol. 2017;953:83-116. doi: 10.1007/978-3-319-46095-6_3.
The challenging task of mitotic cell divisions is to generate two genetically identical daughter cells from a single precursor cell. To accomplish this task, a complex regulatory network evolved, which ensures that all events critical for the duplication of cellular contents and their subsequent segregation occur in the correct order, at specific intervals and with the highest possible fidelity. Transitions between cell cycle stages are triggered by changes in the phosphorylation state and levels of components of the cell cycle machinery. Entry into S-phase and M-phase are mediated by cyclin-dependent kinases (Cdks), serine-threonine kinases that require a regulatory cyclin subunit for their activity. Resetting the system to the interphase state is mediated by protein phosphatases (PPs) that counteract Cdks by dephosphorylating their substrates. To avoid futile cycles of phosphorylation and dephosphorylation, Cdks and PPs must be regulated in a manner such that their activities are mutually exclusive.
有丝分裂细胞分裂的一项具有挑战性的任务是从单个前体细胞产生两个基因相同的子细胞。为了完成这项任务，进化出了一个复杂的调控网络，该网络确保细胞内容物复制及其后续分离所必需的所有事件以正确的顺序、在特定的时间间隔内并以尽可能高的保真度发生。细胞周期各阶段之间的转换由细胞周期机制组件的磷酸化状态和水平的变化触发。进入S期和M期由细胞周期蛋白依赖性激酶（Cdks）介导，Cdks是丝氨酸 - 苏氨酸激酶，其活性需要一个调节性细胞周期蛋白亚基。通过蛋白磷酸酶（PPs）介导将系统重置为间期状态，PPs通过使其底物去磷酸化来对抗Cdks。为了避免磷酸化和去磷酸化的无效循环，Cdks和PPs必须以其活性相互排斥的方式进行调节。
