Seker Hasan, Rubbi Carlos, Linke Steven P, Bowman Elise D, Garfield Susan, Hansen Laura, Borden Katherine L B, Milner Jo, Harris Curtis C
Laboratory of Human Carcinogenesis, CCR, National Cancer Institute, NIH, Bethesda, MD 20892-4255, USA.
Oncogene. 2003 Mar 20;22(11):1620-8. doi: 10.1038/sj.onc.1206140.
The promyelocytic leukemia protein (PML) is a nuclear phosphoprotein that localizes to distinct domains in the nucleus, described as PML nuclear bodies (PML-NBs). Recent findings indicate that PML regulates the p53 response to oncogenic signals. Here, we define a p53-dependent role for PML in response to DNA damage. We exposed cells to ultraviolet light (UV-C) and imaged the nuclear distribution of PML, p53, and the BLM helicase by confocal microscopy. After DNA damage, PML partially relocated out of the PML-NBs, and colocalized with BLM and p53 at sites of DNA repair. In addition, using the isogenic HCT116 cell lines (p53+/+ and -/-), we show that the redistribution of PML was dependent on functional p53. Western analysis revealed that the level of PML protein remained unaltered after UV-C treatment. These results are consistent with the hypothesis that PML, in conjunction with p53 and BLM, contributes to the cellular response to UV-C-induced DNA damage and its repair.
早幼粒细胞白血病蛋白（PML）是一种核磷蛋白，定位于细胞核内不同的区域，即所谓的PML核体（PML-NBs）。最近的研究结果表明，PML可调节p53对致癌信号的反应。在此，我们确定了PML在响应DNA损伤时依赖p53的作用。我们将细胞暴露于紫外线（UV-C）下，并用共聚焦显微镜对PML、p53和BLM解旋酶的核分布进行成像。DNA损伤后，PML部分从PML-NBs中重新定位，并在DNA修复位点与BLM和p53共定位。此外，使用同基因的HCT116细胞系（p53+/+和-/-），我们发现PML的重新分布依赖于功能性p53。蛋白质印迹分析显示，UV-C处理后PML蛋白水平保持不变。这些结果与以下假设一致，即PML与p53和BLM共同作用，有助于细胞对UV-C诱导的DNA损伤及其修复的反应。
