Protein kinase B/Akt may regulate G2/M transition in the fertilized mouse egg by changing the localization of p21Cip1/WAF1
Protein kinase B/Akt may regulate G2/M transition in the fertilized mouse egg by changing the localization of p21Cip1/WAF1
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DOI：
10.1002/cbf.1743
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发表时间：
2011-06
影响因子：
3.6
通讯作者：
Di-di Wu;C. Feng;Xiao‐yan Xu;Jian-ying Xiao;Chao Liu;J. Meng;E. Wang;Bing‐zhi Yu
中科院分区：
文献类型：
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作者：
Di-di Wu;C. Feng;Xiao‐yan Xu;Jian-ying Xiao;Chao Liu;J. Meng;E. Wang;Bing‐zhi Yu
蛋白激酶B(PKB，又称Akt)是一种丝氨酸/苏氨酸蛋白激酶。一些研究表明，Akt信号通路强烈促进哺乳动物细胞周期进程中的G2/M转变，但其机制尚不清楚，特别是在受精卵中。在此，我们报道了Akt在蛋白和mRNA水平上的表达在G2期最高，并伴随着Akt活性的高峰。此外，p21Cip1/WAF1的亚细胞定位在细胞周期中起着至关重要的作用。因此，我们检测了注射Akt基因的受精卵后p21Cip1/WAF1的表达和定位。在显微注射MYR-Akt基因的单细胞期受精胚胎中，p21Cip1/WAF1保留在细胞质中。微量注射蛋白缺陷型Akt(Akt-KD)可导致p21Cip1/WAF1的核定位。同时，微量注射不同类型的Akt mRNA影响p21Cip1/WAF1的磷酸化状态。而p21Cip1/WAF1的蛋白表达无明显差异。因此，Akt通过改变p21Cip1/WAF1的亚细胞定位来控制细胞周期，很可能是通过影响p21Cip1/WAF1的磷酸化状态。版权所有©2011 John Wiley&Sons，Ltd.
Protein kinase B (PKB, also called Akt) is known as a serine/threonine protein kinase. Some studies indicate that the Akt signalling pathway strongly promotes G2/M transition in mammalian cell cycle progression, but the mechanism remains to be clarified, especially in the fertilized mouse egg. Here, we report that the expression of Akt at both the protein and mRNA level was highest in G2 phase, accompanied by a peak of Akt activity. In addition, the subcellular localization of p21Cip1/WAF1 has been proposed to be critical in the cell cycle. Hence, we detected the expression and localization of p21Cip1/WAF1 after injecting fertilized mouse eggs with Akt mRNA. In one‐cell stage fertilized embryos microinjected with mRNA coding for a constitutively active myristoylated Akt (myr‐Akt), p21Cip1/WAF1 was retained in the cytoplasm. Microinjection of mRNA of kinase‐deficient Akt(Akt‐KD) resulted in nuclear localization of p21Cip1/WAF1. Meanwhile, microinjection of different types of Akt mRNA affected the phosphorylation status of p21Cip1/WAF1. However, there was no obvious difference in the protein expression of p21Cip1/WAF1. Therefore, Akt controls the cell cycle by changing the subcellular localization of p21Cip1/WAF1, most likely by affecting the phosphorylation status of p21Cip1/WAF1. Copyright © 2011 John Wiley & Sons, Ltd.