• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The Journal of Reproduction and Development >Preimplantation-embryo-specific Cell-cycle Regulation is Attributable to a Low Expression of Retinoblastoma Protein Rather Than Its Phosphorylation
【24h】

Preimplantation-embryo-specific Cell-cycle Regulation is Attributable to a Low Expression of Retinoblastoma Protein Rather Than Its Phosphorylation

机译：植入前胚胎特异性细胞周期调控可归因于视网膜母细胞瘤蛋白的低表达而不是其磷酸化

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Mammalian preimplantation embryos enter the S phase immediately after the end of the M phase; their cell cycle lacks a substantial G1 phase. Previously, we suggested that the absence of the G1 phase was attributable to a loss of retinoblastoma protein (RB) function, which is required for suppression of S phase entrance and that this loss of RB function in turn was attributable to the low RB expression level during preimplantation development in mouse embryos. The present study aimed to examine whether or not RB inhibition by CDK4/6-cyclin D-dependent phosphorylation is involved in the loss of RB function in preimplantation mouse embryos by the expression of p16INK4a, a potent endogenous inhibitor of CDK4/6-cyclin D. First, the decrease in RB expression between the four-cell and morula stages was confirmed in in vivo -derived mouse embryos. We then examined the efficiency of the p16INK4a expression vector in inhibiting RB phosphorylation and cell cycle progression using NIH-3T3 cells and obtained gradual RB dephosphorylation and a significantly lower proliferation rate in p16INK4a-transfected cells than in control cells. This indicated the successful p16INK4a effects on cell-cycle progression by the vector used. On the other hand, the development rate of mouse embryos injected with the p16INK4a expression vector was the same as that of the control embryos, although p16INK4a expression was detected at mRNA and protein levels in the former group but not in the control group. These results suggest that RB phosphorylation is not involved in RB dysfunction or in the lack of a G1 phase in mouse embryos and that the decrease in RB expression is important for preimplantation-embryo-specific cell-cycle regulation. Moreover, the present study indicates the similarity between preimplantation embryos and cancer cells, which p16INK4a expression does not arrest at the G1 phase.
机译：哺乳动物植入前胚胎在M期结束后立即进入S期。它们的细胞周期缺乏实质性的G1期。以前，我们建议G1期的缺失归因于成视网膜细胞瘤蛋白（RB）功能的丧失，这是抑制S期进入所必需的，而RB功能的丧失又归因于RB表达水平低在小鼠胚胎着床前的发育过程中。本研究旨在通过有效的内源性p16 INK4a 的表达来研究CDK4 / 6-cyclin D依赖性磷酸化对RB的抑制作用是否与植入前小鼠胚胎RB功能的丧失有关。首先，在体内来源的小鼠胚胎中证实了四细胞阶段和桑ula壳阶段之间RB表达的降低。然后，我们使用NIH-3T3细胞检查了p16 INK4a 表达载体在抑制RB磷酸化和细胞周期进程中的效率，并获得了逐渐的RB去磷酸化和p16 INK4a的增殖率明显降低转染的细胞比对照细胞。这表明所用载体对细胞周期进程具有成功的p16 INK4a 作用。另一方面，尽管在mRNA上检测到了p16 INK4a 表达载体，但注射了p16 INK4a 表达载体的小鼠胚胎的发育速度与对照胚胎相同。和蛋白质水平在前一组而不是对照组。这些结果表明，RB磷酸化不参与小鼠胚胎中的RB功能障碍或缺少G1期，并且RB表达的降低对于植入前胚胎特异性细胞周期调控很重要。此外，本研究表明了植入前胚胎与癌细胞之间的相似性，其中p16 INK4a 的表达并不停留在G1期。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号