来自德国康斯坦茨大学的Thomas Tischer及其同事发现XErp1蛋白(也称为Emi2,早期有丝分裂抑制剂2)通过抑制后期促进复合物(APC/C)的活性来调控非洲爪蟾蜍的细胞周期过程。

-2012年10月26日《科学》

中文翻译


【题目】APC/C抑制物XErp1/Emi2是非洲爪蟾蜍早期胚胎分裂所必需的

【译文】细胞周期蛋白依赖性激酶(Cdk1)的振荡活性导致了细胞发生有丝分裂。后期促进复合物(APC/C)会终止Cdk1的活动,APC/C是一种靶向M期细胞周期蛋白、破坏有丝分裂的泛素连接酶。在有丝分裂中,早期有丝分裂抑制剂1(Emi1)和纺锤体组装检查点(SAC)通过抑制APC/C的活性来调控细胞周期过程。但早期胚胎分裂缺乏抑制APC/C复合物的组分,这就存在一个问题:胚胎的细胞周期如何被调控?本研究发现XErp1(也称为Emi2)具有抑制APC/C复合物的活性,这种活性是非洲爪蟾蜍(Xenopus)早期胚胎分裂所必需的。缺失XErp1会导致APC/C的底物过早被破坏和胚胎致死。Cdk1负调控XErp1具有的抑制APC/C复合物的功能,但蛋白磷酸酶2A(PP2A)却能正调控XErp1的功能。总之,Cdk1和PP2A相拮抗地调控XErp1的活性(早期有丝分裂的关键),最终导致APC/C表现出振荡活性。

英文原稿


[Title]: The APC/C Inhibitor XErp1/Emi2 Is Essential for Xenopus Early Embryonic Divisions

[Authors]: Thomas Tischer, Eva Hörmanseder, and Thomas U. Mayer

[Abstract]: Mitotic divisions result from the oscillating activity of cyclin-dependent kinase 1 (Cdk1). Cdk1 activity is terminated by the anaphase-promoting complex/cyclosome (APC/C), a ubiquitin ligase that targets cyclin B for destruction. In somatic divisions, the early mitotic inhibitor 1 (Emi1) and the spindle assembly checkpoint (SAC) regulate cell cycle progression by inhibiting the APC/C. Early embryonic divisions lack these APC/C-inhibitory components, which raises the question of how those cycles are controlled. We found that the APC/C-inhibitory activity of XErp1 (also known as Emi2) was essential for early divisions in Xenopus embryos. Loss of XErp1 resulted in untimely destruction of APC/C substrates and embryonic lethality. XErp1’s APC/C-inhibitory function was negatively regulated by Cdk1 and positively by protein phosphatase 2A (PP2A). Thus, Cdk1 and PP2A operate at the core of early mitotic cell cycles by antagonistically controlling XErp1 activity, which results in oscillating APC/C activity.

原文地址

http://www.sciencemag.org/content/338/6106/520.short

本站声明: 生物文库所有文章欢迎转载,所有文章未说明,均属于原创,转载均请注明出处。
本文链接: http://www.bioku.cn/201212/science-cdk1-pp2a-xerp1-protein-apcc-mitosis-cell-cycle-xenopus/
版权所有: 生物文库 - 生物医学、生物技术核心期刊文摘

留言


7 − 一 =


沪ICP备12028140号
点击这里给我发消息   点击这里给我发消息