Structural basis for recognition of Emi2 by Polo-like kinase 1 and development of peptidomimetics blocking oocyte maturation and fertilization.
Structural basis for recognition of Emi2 by Polo-like kinase 1 and development of peptidomimetics blocking oocyte maturation and fertilization.
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DOI：
10.1038/srep14626
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发表时间：
2015-10-13
影响因子：
4.6
通讯作者：
Namgoong S
中科院分区：
文献类型：
--
作者：
Jia JL;Han YH;Kim HC;Ahn M;Kwon JW;Luo Y;Gunasekaran P;Lee SJ;Lee KS;Kyu Bang J;Kim NH;Namgoong S
在哺乳动物卵母细胞中，减数分裂的完成被暂停，直到精子受精，细胞周期被称为细胞生长抑制因子（CSF）的生化活性所阻止。CSF 2是CSFs中的一种，它通过抑制泛素连接酶后期促进复合物/细胞周期体（APC/C）来维持成熟促进因子（MPF）的蛋白水平。受精后通过遍在蛋白介导的蛋白水解降解Emi 2需要Polo样激酶1（Plk 1）的磷酸化。因此，Plk 1识别和磷酸化P172是细胞周期恢复的关键步骤，但P172和Plk 1的结合模式知之甚少。使用生化分析和X射线晶体学，我们发现，两个磷酸化的苏氨酸（Thr 152和Thr 176）在BMP 2是每个负责一个Plk 1分子的招聘结合到其C-末端波罗盒结构域（PBD）。我们还发现，减数分裂成熟和减数分裂恢复通过孤雌激活受损时，与Plk 1-PBD的相互作用被称为103-8的肽模拟物阻断。由于激酶抑制剂的固有混杂性，我们的研究结果表明，针对Plk 1的PBD可能是开发阻断卵母细胞成熟和/或受精的新型和特异性避孕药的有效策略。
In a mammalian oocyte, completion of meiosis is suspended until fertilization by a sperm, and the cell cycle is arrested by a biochemical activity called cytostatic factor (CSF). Emi2 is one of the CSFs, and it maintains the protein level of maturation promoting factor (MPF) by inhibiting ubiquitin ligase anaphase promoting complex/cyclosome (APC/C). Degradation of Emi2 via ubiquitin-mediated proteolysis after fertilization requires phosphorylation by Polo-like kinase 1 (Plk1). Therefore, recognition and phosphorylation of Emi2 by Plk1 are crucial steps for cell cycle resumption, but the binding mode of Emi2 and Plk1 is poorly understood. Using biochemical assays and X-ray crystallography, we found that two phosphorylated threonines (Thr152 and Thr176) in Emi2 are each responsible for the recruitment of one Plk1 molecule by binding to its C-terminal polo box domain (PBD). We also found that meiotic maturation and meiosis resumption via parthenogenetic activation were impaired when Emi2 interaction with Plk1-PBD was blocked by a peptidomimetic called 103-8. Because of the inherent promiscuity of kinase inhibitors, our results suggest that targeting PBD of Plk1 may be an effective strategy for the development of novel and specific contraceptive agents that block oocyte maturation and/or fertilization.