Acetylation of histone H4 plays a primary role in enhancing transcription factor binding to nucleosomal DNA in vitro
Acetylation of histone H4 plays a primary role in enhancing transcription factor binding to nucleosomal DNA in vitro
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DOI：
10.1002/j.1460-2075.1996.tb00608.x
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发表时间：
1996-05-15
期刊：
影响因子：
11.4
通讯作者：
Workman, JL
中科院分区：
文献类型：
--
作者：
VetteseDadey, M;Grant, PA;Workman, JL
为了分析组蛋白乙酰化在增强转录因子与核小体DNA中识别位点结合中的作用，从正常和丁酸盐处理的HeLa细胞中分离的核心组蛋白已被重构成核小体核心。使用不均匀乙酰化的组蛋白，观察到碱性螺旋-环-螺旋因子USF和Zn簇DNA结合域因子GAL 4-AH对核小体结合的适度刺激。然而，通过将新的免疫印迹技术与凝胶阻滞试验相结合，我们观察到含有最高度乙酰化形式的组蛋白H4的核小体核心对这两种转录因子具有最高的亲和力。凝胶纯化的USF-核小体和GAL 4-AH-核小体复合物的Western分析表明，相对于乙酰化组蛋白H3，乙酰化组蛋白H4占优势。用抗USF抗体免疫沉淀USF-核小体复合物也表明，这些复合物优先富集乙酰化组蛋白H4，这些数据表明USF和GAL 4-AH优先与含有高度乙酰化组蛋白H4的核小体核心相互作用。因此，组蛋白H4的乙酰化似乎在介导转录因子与其核小体内识别位点的结合增强的结构变化中起主要作用。
Core histones isolated from normal and butyrate-treated HeLa cells have been reconstituted into nucleosome cores in order to analyze the role of histone acetylation in enhancing transcription factor binding to recognition sites in nucleosomal DNA, Moderate stimulation of nucleosome binding was observed for the basic helix-loop-helix factor USF and the Zn cluster DNA binding domain factor GAL4-AH using heterogeneously acetylated histones, However, by coupling novel immunoblotting techniques to a gel retardation assay, we observed that nucleosome cores containing the most highly acetylated forms of histone H4 have the highest affinity for these two transcription factors. Western analysis of gel-purified USF-nucleosome and GAL4-AH-nucleosome complexes demonstrated the predominant presence of acetylated histone H4 relative to acetylated histone H3, Immunoprecipitation of USF-nucleosome complexes with anti-USF antibodies also demonstrated that these complexes were enriched preferentially in acetylated histone H4, These data show that USF and GAL4-AH preferentially interact with nucleosome cores containing highly acetylated histone H4. Acetylation of histone H4 thus appears to play a primary role in the structural changes that mediate enhanced binding of transcription factors to their recognition sites within nucleosomes.