Redox state of tumor suppressor p53 regulates its sequence-specific DNA binding in DNA-damaged cells by cysteine 277
Redox state of tumor suppressor p53 regulates its sequence-specific DNA binding in DNA-damaged cells by cysteine 277
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DOI：
10.1093/nar/30.11.2340
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发表时间：
2002-06-01
影响因子：
14.9
通讯作者：
Laiho, M
中科院分区：
文献类型：
--
作者：
Buzek, J;Latonen, L;Laiho, M
使用生物寡聚下拉DNA结合试验，我们研究了内源性，DNA损伤诱导的p53在人二倍体成纤维细胞的结合能力，几个p53反应元件（RE）存在于p53调控基因。在p53积累的过程中，我们观察到p53与GADD 45的结合减少，但不与p21（WAF 1/CIP 1）RE结合。使用突变的GADD 45序列，我们表明，这种变化是依赖于在位置3的RE五聚体和p53的氧化还原状态的胞嘧啶的存在。定点诱变实验表明，Cys 277（一个残基直接接触的RE五聚体中的碱基3）是关键的差异调节GADD 45在DNA损伤的细胞。这些数据代表了p53对不同RE的差异亲和力的新机制。
Using a bio-oligo pull-down DNA-binding assay we investigated the binding capacity of endogenous, DNA damage-induced p53 in human diploid fibroblasts to several p53-responsive elements (REs) present in p53-regulated genes. During the course of p53 accumulation, we observed a decrease in p53 binding to the GADD45 but not to the p21(WAF1/CIP1) RE. Using mutated GADD45 sequences we show that this change is dependent on the presence of cytosines at position 3 in RE pentamers and on the p53 redox state. Site-directed mutagenesis experiments demonstrated that Cys277 (a residue directly contacting base 3 in a RE pentamer) is critical for differential regulation of GADD45 in DNA-damaged cells. These data represent a novel mechanism for differential affinity of p53 to distinct REs.