Expression of constitutively active CDK1 stabilizes APC-Cdh1 substrates and potentiates premature spindle assembly and checkpoint function in G1 cells.
Expression of constitutively active CDK1 stabilizes APC-Cdh1 substrates and potentiates premature spindle assembly and checkpoint function in G1 cells.
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DOI：
10.1371/journal.pone.0033835
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Pomerening JR
中科院分区：
文献类型：
--
作者：
Ma Y;Yuan X;Wyatt WR;Pomerening JR
真核细胞有丝分裂的进程依赖于细胞周期蛋白依赖性激酶1（CDK 1）的激活，随后通过后期促进复合物（APC）/细胞环体介导的M期细胞周期蛋白的降解使其失活。以前的工作表明，在HeLa细胞中表达组成型活性CDK 1（CDK 1AF）允许它们分裂，但产生G1子代细胞，经历过早的S期和早期有丝分裂事件。虽然发现CDK 1AF阻碍APC-Cdh 1的持续活性，但尚不清楚这种缺陷是否不适当地稳定了有丝分裂底物并导致了这些过早M期的发生。在这里，我们表明，CDK 1AF在HeLa细胞中的表达不适当地稳定APC-Cdh 1基板在G1期的子细胞，包括有丝分裂激酶和APC适配器，Cdc 20。分裂CDK 1AF表达细胞产生G1女儿与加速S期发作，中断的形成过早的双极纺锤体能够纺锤体组装检查点功能。对CDK 1AF表达诱导的这些表型的进一步表征显示，这种早期纺锤体形成依赖于过早的CDK 1和Aurora B活性，并且它们的抑制诱导了纺锤体的快速分解。在其正常的M期降解后，我们发现在这些过早循环的子细胞中没有Wee 1允许内源性CDK 1促进这些过早的有丝分裂事件，因为不可降解的Wee 1的表达减少了表现出过早的细胞周期蛋白B1振荡的细胞数量。最后，我们发现，Cdh 1消融细胞不能被迫进入一个过早的M期，尽管细胞周期蛋白B1过表达和蛋白酶体抑制。总之，这些结果表明，组成型活性CDK 1AF的表达阻碍了关键APC-Cdh 1靶点的破坏，并且这种类型的条件可以阻止新分裂的细胞适当地维持延长的间期状态。我们认为，APC驱动的负反馈环的活性中的这种更微妙类型的缺陷可能对触发基因组不稳定性和肿瘤发生具有影响。
Mitotic progression in eukaryotic cells depends upon the activation of cyclin-dependent kinase 1 (CDK1), followed by its inactivation through the anaphase-promoting complex (APC)/cyclosome-mediated degradation of M-phase cyclins. Previous work revealed that expression of a constitutively active CDK1 (CDK1AF) in HeLa cells permitted their division, but yielded G1 daughter cells that underwent premature S-phase and early mitotic events. While CDK1AF was found to impede the sustained activity of APC-Cdh1, it was unknown if this defect improperly stabilized mitotic substrates and contributed to the occurrence of these premature M phases. Here, we show that CDK1AF expression in HeLa cells improperly stabilized APC-Cdh1 substrates in G1-phase daughter cells, including mitotic kinases and the APC adaptor, Cdc20. Division of CDK1AF-expressing cells produced G1 daughters with an accelerated S-phase onset, interrupted by the formation of premature bipolar spindles capable of spindle assembly checkpoint function. Further characterization of these phenotypes induced by CDK1AF expression revealed that this early spindle formation depended upon premature CDK1 and Aurora B activities, and their inhibition induced rapid spindle disassembly. Following its normal M-phase degradation, we found that the absence of Wee1 in these prematurely cycling daughter cells permitted the endogenous CDK1 to contribute to these premature mitotic events, since expression of a non-degradable Wee1 reduced the number of cells that exhibited premature cyclin B1oscillations. Lastly, we discovered that Cdh1-ablated cells could not be forced into a premature M phase, despite cyclin B1 overexpression and proteasome inhibition. Together, these results demonstrate that expression of constitutively active CDK1AF hampers the destruction of critical APC-Cdh1 targets, and that this type of condition could prevent newly divided cells from properly maintaining a prolonged interphase state. We propose that this more subtle type of defect in activity of the APC-driven negative-feedback loop may have implications for triggering genome instability and tumorigenesis.
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DOI：
10.1083/jcb.134.4.963
发表时间：
1996-08
期刊：
The Journal of cell biology
影响因子：
--
作者：
Jin P;Gu Y;Morgan DO
通讯作者：
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影响因子：
64.5
作者：
Bassermann, Florian;Frescas, David;Guardavaccaro, Daniele;Busino, Luca;Peschiaroli, Angelo;Pagano, Michele
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影响因子：
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作者：
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通讯作者：
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影响因子：
3.3
作者：
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DOI：
10.1083/jcb.200208092
发表时间：
2003-04-28
期刊：
The Journal of cell biology
影响因子：
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作者：
Hauf S;Cole RW;LaTerra S;Zimmer C;Schnapp G;Walter R;Heckel A;van Meel J;Rieder CL;Peters JM
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