Cell Cycle- and Chromatin Binding State-dependent Phosphorylation of Human MCM Heterohexameric Complexes
Cell Cycle- and Chromatin Binding State-dependent Phosphorylation of Human MCM Heterohexameric Complexes
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人 MCM 异六聚体复合物的细胞周期和染色质结合状态依赖性磷酸化
DOI：
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发表时间：
1998
影响因子：
4.8
通讯作者：
M. Inagaki
中科院分区：
文献类型：
--
作者：
M. Fujita;Chieko Yamada;T. Tsurumi;F. Hanaoka;K. Matsuzawa;M. Inagaki
哺乳动物MCM蛋白家族目前有6个成员，以染色质结合和未结合两种形式存在于细胞核中。前者从染色质中解离，并通过S期进行。最近，我们已经建立了一个程序，分离染色质结合和未结合的复合物含有所有六个人MCM（hMCM）蛋白的免疫沉淀。在本研究中，我们应用此程序的HeLa细胞同步在每个G1，S和G2/M期，并可以检测hMCM heterohexameric复合物在所有三个。此外，根据细胞周期和染色质缔合状态，复合物中的hMCM 2和4被发现不同地改变其磷酸化状态。在G2/M期过度磷酸化的情况下，我们发现复合物中的hMCM 2和4是cdc 2/cyclin B的良好底物。此外，当cdc 2激酶失活的温度敏感的突变型小鼠FT 210细胞，G2/M过度磷酸化的小鼠MCM 2和MCM 4和释放的MCMs从染色质在G2期严重受损。两者合计，数据表明，6哺乳动物MCM蛋白的功能和进行细胞周期依赖性调节作为异六聚体复合物和磷酸化的复合物由cdc 2激酶可能是负调节MCM复合物染色质协会的机制之一。
The mammalian MCM protein family, presently with six members, exists in the nuclei in two forms, chromatin-bound and unbound. The former dissociates from chromatin with progression through the S phase. Recently, we have established a procedure to isolate chromatin-bound and unbound complexes containing all six human MCM (hMCM) proteins by immunoprecipitation. In the present study, we applied this procedure to HeLa cells synchronized in each of the G1, S, and G2/M phases and could detect hMCM heterohexameric complexes in all three. In addition, depending on the cell cycle and the state of chromatin association, hMCM2 and 4 in the complexes were found to variously change their phosphorylation states. Concentrating attention on G2/M phase hyperphosphorylation, we found hMCM2 and 4 in the complexes to be good substrates for cdc2/cyclin B in vitro. Furthermore, when cdc2 kinase was inactivated in temperature-sensitive mutant murine FT210 cells, the G2/M hyperphosphorylation of the murine MCM2 and MCM4 and release of the MCMs from chromatin in the G2 phase were severely impaired. Taken together, the data suggest that the six mammalian MCM proteins function and undergo cell cycle-dependent regulation as heterohexameric complexes and that phosphorylation of the complexes by cdc2 kinase may be one of mechanisms negatively regulating the MCM complex-chromatin association.
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Mcm2 和 Mcm3 是对 ARS 活性很重要的两种蛋白质，它们在结构和功能上相关。
影响因子：
10.5
作者：
Yan,H;Gibson,S;Tye,BK
通讯作者：
Tye,BK
影响因子：
10.5
作者：
Hong Yan;Ankit Margaret Merchant;B. Tye
通讯作者：
Hong Yan;Ankit Margaret Merchant;B. Tye
DOI：
10.1073/pnas.89.21.10459
发表时间：
1992-11-01
影响因子：
11.1
作者：
CHEN, YR;HENNESSY, KM;TYE, BK
通讯作者：
TYE, BK
果蝇 MCM 蛋白复合物。
影响因子：
3.3
作者：
Su,TT;Feger,G;O'Farrell,PH
通讯作者：
O'Farrell,PH