Copper uptake is required for pyrrolidine dithiocarbamate-mediated oxidation and protein level increase of p53 in cells
Copper uptake is required for pyrrolidine dithiocarbamate-mediated oxidation and protein level increase of p53 in cells
复制标题
DOI：
10.1042/bj20011251
复制
发表时间：
2002-08-01
影响因子：
4.1
通讯作者：
Momand, J
中科院分区：
文献类型：
--
作者：
Furuta, S;Ortiz, F;Momand, J
p53肿瘤抑制蛋白是一种转录因子，其激活参与细胞周期停滞、凋亡和DNA修复的基因的表达。p53蛋白在半胱氨酸巯基处易受氧化。金属螯合二硫代氨基甲酸酯，吡咯烷二硫代氨基甲酸酯（PDTC），二乙基二硫代氨基甲酸酯，亚乙基（双）二硫代氨基甲酸酯和过氧化氢进行了测试，在培养的人乳腺癌细胞对p53的氧化作用。只有PDTC氧化p53，尽管所有测试的氧化剂都增加了p53水平。电感耦合等离子体MS分析表明，加入60 μ M PDTC增加了细胞铜浓度的4倍，这是最高水平的铜积累在所有的氧化剂测试。Bathocuproinedisulphonic acid是一种膜不可渗透的Cu（I）螯合剂，可抑制PDTC介导的铜积累。Bathocuproinedisulfonic acid以及羟基自由基清除剂D-甘露醇抑制了p53蛋白和氧化的PDT依赖性增加。我们的研究结果表明，在25-40 μ g/g细胞蛋白范围内的低水平铜积累增加了p53的稳态水平。当铜积累水平高于60 μ g/g细胞蛋白时，p53被氧化。这些结果表明，p53是脆弱的自由基介导的氧化在半胱氨酸残基。
The p53 tumour-suppressor protein is a transcription factor that activates the expression of genes involved in cell cycle arrest, apoptosis and DNA repair. The p53 protein is vulnerable to oxidation at cysteine thiol groups. The metal-chelating dithiocarbamates, pyrrolidine dithiocarbamate (PDTC), diethyldithiocarbamate, ethylene(bis)dithiocarbamate and H2O2 were tested for their oxidative effects on p53 in cultured human breast cancer cells. Only PDTC oxidized p53, although all oxidants tested increased the p53 level. Inductively coupled plasma MS analysis indicated that the addition of 60 muM PDTC increased the cellular copper concentration by 4-fold, which was the highest level of copper accumulated amongst all the oxidants tested. Bathocuproinedisulphonic acid, a membrane-impermeable Cu(I) chelator inhibited the PDTC-mediated copper accumulation. Bathocuproinedisulphonic acid as well as the hydroxyl radical scavenger D-mannitol inhibited the PDTC-dependent increase in p53 protein and oxidation. Our results show that a low level of copper accumulation in the range of 25-40 mug/g of cellular protein increases the steady-state levels of p53. At copper accumulation levels higher than 60 mug/g of cellular protein, p53 is oxidized. These results suggest that p53 is vulnerable to free radical-mediated oxidation at cysteine residues.