p65 Negatively Regulates Transcription of the Cyclin E Gene
p65 Negatively Regulates Transcription of the Cyclin E Gene
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DOI：
10.1074/jbc.m109.058974
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发表时间：
2010-06-04
影响因子：
4.8
通讯作者：
Kumar, Vijay
中科院分区：
文献类型：
--
作者：
Janbandhu, Vaibhao C.;Singh, Anup K.;Kumar, Vijay
NF-κ B家族成员在许多细胞和生物体功能中发挥关键作用，包括细胞周期。NF-κ B作为细胞周期蛋白D1和p21（Waf 1）基因的激活剂，被认为是细胞周期的重要调节因子。为了研究NF-κ B在G（1）/S期调节中的参与，在NF-κ B过表达或肿瘤坏死因子-α对其进行生理诱导后监测所选转录调节因子的水平。Cyclin E基因是NF-κ B B的主要转录靶基因。NF-κ B B在细胞周期蛋白E启动子的募集与细胞周期蛋白E基因的反式阻遏相关。连接介导的PCR和微球菌核酸酶-Southern分析表明该区域的核小体性质，而染色质免疫沉淀分析证实了肿瘤坏死因子-α治疗或血清饥饿释放后辅因子的交换。细胞周期蛋白E的转录沿着减少，同时细胞周期蛋白E-cdk 2复合物的催化活性降低，细胞停滞在G（1）/S期。因此，我们的研究清楚地表明NF-κ B B是通过转录抑制细胞周期蛋白E来调控细胞周期的负调控因子。
NF-kappa B family members play a pivotal role in many cellular and organismal functions, including the cell cycle. As an activator of cyclin D1 and p21(Waf1) genes, NF-kappa B has been regarded as a critical modulator of cell cycle. To study the involvement of NF-kappa B in G(1)/S phase regulation, the levels of selected transcriptional regulators were monitored following overexpression of NF-kappa B or its physiological induction by tumor necrosis factor-alpha. Cyclin E gene was identified as a major transcriptional target of NF-kappa B. Recruitment of NF-kappa B to the cyclin E promoter was correlated with the transrepression of cyclin E gene. Ligation-mediated PCR and micrococcal nuclease-Southern assays suggested the nucleosomal nature of this region while chromatin immunoprecipitation analysis confirmed the exchange of cofactors following tumor necrosis factor-alpha treatment or release from serum starvation. There was a progressive reduction in cyclin E transcription along with the accumulation of catalytically inactive cyclin E-cdk2 complexes and arrest of cells in G(1)/S-phase. Thus, our study clearly establishes NF-kappa B as a negative regulator of cell cycle through transcriptional repression of cyclin E.