PHORBOL ESTER ABROGATES UP-REGULATION OF DNA-POLYMERASE-BETA BY DNA-ALKYLATING AGENTS IN CHINESE-HAMSTER OVARY CELLS
PHORBOL ESTER ABROGATES UP-REGULATION OF DNA-POLYMERASE-BETA BY DNA-ALKYLATING AGENTS IN CHINESE-HAMSTER OVARY CELLS
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DOI：
10.1074/jbc.270.27.16402
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发表时间：
1995-07-07
影响因子：
4.8
通讯作者：
WILSON, SH
中科院分区：
文献类型：
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作者：
SRIVASTAVA, DK;RAWSON, TY;WILSON, SH
哺乳动物DNA聚合酶β（β-pol）是一种DNA修复聚合酶，已知在培养的细胞中组成型表达，但用DNA烷基化剂MNNG或甲磺酸甲酯处理细胞已显示上调β-pol mRNA水平。为了进一步表征这种反应，我们制备了一组单克隆抗体，并使用其中之一通过免疫印迹法定量全细胞提取物中的β-pol。我们发现，用DNA烷基化剂处理中国仓鼠卵巢细胞可使β-pol蛋白水平上调5-10倍。这种诱导似乎是继发于DNA烷基化，因为在过表达DNA修复酶O-6-甲基鸟嘌呤-甲基转移酶的遗传改变的细胞系中没有观察到诱导。我们还发现，12-O-十四烷酰基佛波醇-13-乙酸酯（TPA）处理野生型中国仓鼠卵巢细胞增加了β-pol蛋白的表达（类似于10倍）。通过用MNNG和TPA的组合处理来研究TPA响应和DNA烷基化响应之间的任何相互关系。用MNNG处理观察到的β-pol上调被TPA废除，相反，用TPA处理观察到的上调被MNNG废除。
Mammalian DNA polymerase beta (beta-pol), a DNA repair polymerase, is known to be constitutively expressed in cultured cells, but treatment of cells with the DNA-alkylating agents MNNG or methyl methanesulfonate has been shown to up-regulate beta-pol mRNA level. To further characterize this response, we prepared a panel of monoclonal antibodies and used one of them to quantify beta-pol in whole cell extracts by immunoblotting. We found that treatment of Chinese hamster ovary cells with either DNA-alkylating agent up-regulated the beta-pol protein level 5-10-fold. This induction appeared to be secondary to DNA alkylation, as induction was not observed with a genetically altered cell line overexpressing the DNA repair enzyme O-6-methylguanine-methyltransferase We also found that 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment of wild type Chinese hamster ovary cells increased expression of beta-pol protein (similar to 10-fold). Any interrelationship between this TPA response and the DNA-alkylation response was studied by treatment with combinations of MNNG and TPA. The beta-pol up-regulation observed with MNNG treatment was abrogated by TPA, and conversely the up-regulation observed with TPA treatment was abrogated by MNNG.