Runx1 binds as a dimeric complex to overlapping Runx1 sites within a palindromic element in the human GM-CSF enhancer.
Runx1 binds as a dimeric complex to overlapping Runx1 sites within a palindromic element in the human GM-CSF enhancer.
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DOI：
10.1093/nar/gkq356
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发表时间：
2010-10
影响因子：
14.9
通讯作者：
Cockerill PN
中科院分区：
文献类型：
--
作者：
Bowers SR;Calero-Nieto FJ;Valeaux S;Fernandez-Fuentes N;Cockerill PN
Runx1是一种发育调节的转录因子，对造血至关重要。Runx1可以作为单体与核心一致序列TGTGG结合，但作为异二聚体与非dna结合蛋白CBF - β结合更有效，成为称为核心结合因子（CBF）的复合物。在这里，我们证明了CBF也可以在人粒细胞巨噬细胞集落刺激因子增强子的回文序列TGTGGCTGCCCACA的两个重叠Runx1位点上作为二聚体复合物组装。此外，我们证明Runx1与增强子的结合在染色质可及性水平上受到严格控制，并且依赖于事先诱导的NFAT和AP-1，它们会破坏该区域定位的核小体。我们采用体内足迹来证明，在激活增强子后，这两个位点都被有效地占用。体外结合实验证实，两个CBF复合物可以同时结合该位点，转染实验表明，这两个位点都对增强子功能有显著贡献。基于Runx1/CBFβ/DNA晶体结构的计算机模型进一步显示，两个CBF分子可能与这类回文序列结合，形成二聚体复合物，其中两个CBF复合物中的Runx1和CBFβ紧密排列。
Runx1 is a developmentally regulated transcription factor that is essential for haemopoiesis. Runx1 can bind as a monomer to the core consensus sequence TGTGG, but binds more efficiently as a hetero-dimer together with the non-DNA binding protein CBFβ as a complex termed core binding factor (CBF). Here, we demonstrated that CBF can also assemble as a dimeric complex on two overlapping Runx1 sites within the palindromic sequence TGTGGCTGCCCACA in the human granulocyte macrophage colony-stimulating factor enhancer. Furthermore, we demonstrated that binding of Runx1 to the enhancer is rigidly controlled at the level of chromatin accessibility, and is dependent upon prior induction of NFAT and AP-1, which disrupt a positioned nucleosome in this region. We employed in vivo footprinting to demonstrate that, upon activation of the enhancer, both sites are efficiently occupied. In vitro binding assays confirmed that two CBF complexes can bind this site simultaneously, and transfection assays demonstrated that both sites contribute significantly to enhancer function. Computer modelling based on the Runx1/CBFβ/DNA crystal structure further revealed that two molecules of CBF could potentially bind to this class of palindromic sequence as a dimeric complex in a conformation whereby both Runx1 and CBFβ within the two CBF complexes are closely aligned.
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影响因子：
5.4
作者：
MELNIKOVA, IN;CRUTE, BE;SPECK, NA
通讯作者：
SPECK, NA
影响因子：
5.4
作者：
GOLEMIS, EA;SPECK, NA;HOPKINS, N
通讯作者：
HOPKINS, N
影响因子：
1.3
作者：
Cockerill, PN
通讯作者：
Cockerill, PN
DOI：
10.1038/86264
发表时间：
2001-04-01
期刊：
NATURE STRUCTURAL BIOLOGY
影响因子：
--
作者：
Bravo, J;Li, Z;Warren, AJ
通讯作者：
Warren, AJ
影响因子：
11.4
作者：
Kim, WY;Sieweke, M;Ito, Y
通讯作者：
Ito, Y