Laboratory of Transcriptional Networks, Centre for Integrative Biology (CIBIO), University of Trento, TN, 38060 Italy, Molecular Mutagenesis and DNA Repair Unit, IRCSS Azienda Ospedaliera Universitaria San Martino-IST-Istituto Nazionale per la Ricerca sul Cancro, Genoa 16132, Italy, Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA and Chromosome Stability Group, Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIEHS, NIH, RTP, NC, 27709, USA.
Nucleic Acids Res. 2013 Oct;41(18):8637-53. doi: 10.1093/nar/gkt657. Epub 2013 Jul 26.
Structural and biochemical studies have demonstrated that p73, p63 and p53 recognize DNA with identical amino acids and similar binding affinity. Here, measuring transactivation activity for a large number of response elements (REs) in yeast and human cell lines, we show that p53 family proteins also have overlapping transactivation profiles. We identified mutations at conserved amino acids of loops L1 and L3 in the DNA-binding domain that tune the transactivation potential nearly equally in p73, p63 and p53. For example, the mutant S139F in p73 has higher transactivation potential towards selected REs, enhanced DNA-binding cooperativity in vitro and a flexible loop L1 as seen in the crystal structure of the protein-DNA complex. By studying, how variations in the RE sequence affect transactivation specificity, we discovered a RE-transactivation code that predicts enhanced transactivation; this correlation is stronger for promoters of genes associated with apoptosis.
结构和生化研究表明，p73、p63 和 p53 识别 DNA 的氨基酸相同，结合亲和力也相似。在这里，我们通过在酵母和人类细胞系中测量大量反应元件 (RE) 的转录激活活性，表明 p53 家族蛋白也具有重叠的转录激活谱。我们在 DNA 结合域的环 L1 和 L3 中的保守氨基酸上发现了突变，这些突变几乎可以在 p73、p63 和 p53 中同等地调节转录激活潜力。例如，p73 中的 S139F 突变体对选定的 RE 具有更高的转录激活潜力，体外 DNA 结合协同作用增强，并且在蛋白质-DNA 复合物的晶体结构中可以看到灵活的 L1 环。通过研究 RE 序列的变化如何影响转录激活特异性，我们发现了一个 RE 转录激活密码，可以预测增强的转录激活；对于与凋亡相关的基因的启动子，这种相关性更强。
