Weinberg Richard L, Veprintsev Dmitry B, Bycroft Mark, Fersht Alan R
Cambridge University Chemical Laboratory and MRC Centre for Protein Engineering, Medical Research Council Centre, Hills Road, Cambridge CB2 2QH, UK.
J Mol Biol. 2005 May 6;348(3):589-96. doi: 10.1016/j.jmb.2005.03.014.
Tumor suppressor p53 is a transcription factor that transactivates a wide range of genes, including those in DNA repair, cell cycle arrest, apoptosis and its own degradation. To estimate the role of selectivity in binding to its promoters, we measured the binding affinities of a tetrameric p53 construct (p53CT) in vitro with 20 of its recognition elements from a variety of representative genes. The binding of full length p53 to four representative sequences exactly paralleled the affinities to p53CT. The binding of p53 to different recognition elements was co-operative and the affinities varied by up to 50-fold. p53 bound with high affinity to the recognition elements of all the genes involved in cell cycle arrest and some of the genes in apoptosis. All of the lower affinity-binding sites were in genes involved in apoptosis. Our quantitative-binding data were in agreement with published cell-based assays. The regulation of p53 activity is in part determined through the specificity of its DNA-binding interactions.
肿瘤抑制因子p53是一种转录因子，可反式激活多种基因，包括参与DNA修复、细胞周期阻滞、细胞凋亡及其自身降解的基因。为了评估选择性在与启动子结合中的作用，我们在体外测量了一种四聚体p53构建体（p53CT）与来自各种代表性基因的20个识别元件的结合亲和力。全长p53与四个代表性序列的结合与对p53CT的亲和力完全平行。p53与不同识别元件的结合是协同的，亲和力相差高达50倍。p53与所有参与细胞周期阻滞的基因以及一些参与细胞凋亡的基因的识别元件具有高亲和力结合。所有低亲和力结合位点都存在于参与细胞凋亡的基因中。我们的定量结合数据与已发表的基于细胞的分析结果一致。p53活性的调节部分是通过其DNA结合相互作用的特异性来确定的。
