Cyclin B expression in HeLa cells during the G2 block induced by ionizing radiation.
Cyclin B expression in HeLa cells during the G2 block induced by ionizing radiation.
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DOI：
10.1016/b978-0-12-168561-4.50651-x
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发表时间：
1991-10
期刊：
影响因子：
11.2
通讯作者：
R. Muschel;Hong Bing Zhang;G. Iliakis;W. Gillies McKenna;Radiation Oncology
中科院分区：
文献类型：
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作者：
R. Muschel;Hong Bing Zhang;G. Iliakis;W. Gillies McKenna;Radiation Oncology
暴露于电离辐射后，真核细胞经历分裂延迟，这反映在细胞周期g2部分花费的时间增加。最近的信息表明，有丝分裂周期蛋白水平的升高是启动有丝分裂的关键生化事件。在HeLa细胞中，细胞周期蛋白B mRNA和蛋白水平在g2时升高，在分裂完成后下降。细胞周期蛋白B与cdc2结合，导致组蛋白激酶活性，这是有丝分裂起始所必需的。因此，我们选择研究辐照如何干扰细胞周期蛋白B mRNA和蛋白水平，以进一步了解电离辐射导致分裂延迟的机制。我们的实验表明，至少有两种影响细胞周期蛋白B的调控可能导致细胞分裂延迟：(a)当HeLa细胞在S期照射时，细胞周期蛋白B mRNA的积累延迟；(b)当细胞在g2期辐射时，mRNA水平升高，细胞分裂延迟，同时细胞周期蛋白b蛋白水平明显降低，尽管mRNA水平很高。
After exposure to ionizing radiation, eukaryotic cells undergo a division delay which is reflected by increased time spent in the G2portion of the cell cycle. Recent information identifies increased levels of mitotic cyclins as key biochemical events initiating mitosis. In HeLa cells cyclin B mRNA and protein levels have been shown to increase in G2and to decrease after division is completed. Cyclin B protein binds to cdc2, resulting in histone kinase activity which is necessary for the initiation of mitosis. Accordingly, we chose to investigate how cyclin B mRNA and protein levels were perturbed by irradiation in order to gain further understanding of the mechanisms by which ionizing radiation leads to a division delay. Our experiments revealed at least two effects on cyclin B regulation which might contribute to the division delay: (a) when HeLa cells were irradiated in S phase, there was a delay in the accumulation of cyclin B mRNA; (b) when cells were radiated in G2phase, at a time when mRNA levels were increasing, a division delay was induced which coincided with a markedly lowered level of cyclin B protein despite high levels of the mRNA.