Department of Biochemistry & Molecular Biology, Leonard Miller School of Medicine, University of Miami, Miami, FL 33136, United States.
Department of Biochemistry & Molecular Biology, Leonard Miller School of Medicine, University of Miami, Miami, FL 33136, United States.
Arch Biochem Biophys. 2014 May 1;549:1-11. doi: 10.1016/j.abb.2014.03.005. Epub 2014 Mar 18.
In response to a wide variety of stimuli such as growth factors and hormones, EGR1 transcription factor is rapidly induced and immediately exerts downstream effects central to the maintenance of cellular homeostasis. Herein, our biophysical analysis reveals that DNA sequence variations within the target gene promoters tightly modulate the energetics of binding of EGR1 and that nucleotide substitutions at certain positions are much more detrimental to EGR1-DNA interaction than others. Importantly, the reduction in binding affinity poorly correlates with the loss of enthalpy and gain of entropy-a trend indicative of a complex interplay between underlying thermodynamic factors due to the differential role of water solvent upon nucleotide substitution. We also provide a rationale for the physical basis of the effect of nucleotide substitutions on the EGR1-DNA interaction at atomic level. Taken together, our study bears important implications on understanding the molecular determinants of a key protein-DNA interaction at the cross-roads of human health and disease.
针对各种刺激物，如生长因子和激素，EGR1 转录因子迅速被诱导，并立即对维持细胞内稳态的核心下游效应产生影响。在此，我们的生物物理分析揭示，靶基因启动子中的 DNA 序列变异可严格调节 EGR1 结合的能量，并且某些位置的核苷酸取代比其他位置对 EGR1-DNA 相互作用的破坏性更大。重要的是，结合亲和力的降低与焓的损失和熵的增加相关性较差，这一趋势表明由于核苷酸取代后水溶剂的作用不同，基础热力学因素之间存在复杂的相互作用。我们还为核苷酸取代对 EGR1-DNA 相互作用的原子水平的影响提供了一个基本原理。总之，我们的研究对于理解人类健康和疾病交叉点上关键蛋白-DNA 相互作用的分子决定因素具有重要意义。
