The DBD-α4 helix of EWS::FLI is required for GGAA microsatellite binding that underlies genome regulation in Ewing sarcoma.
The DBD-α4 helix of EWS::FLI is required for GGAA microsatellite binding that underlies genome regulation in Ewing sarcoma.
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EWS::FLI 的 DBD-α4 螺旋是 GGAA 微卫星结合所必需的，是尤文肉瘤基因组调控的基础。
DOI：
10.1101/2024.01.31.578127
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发表时间：
2024
期刊：
影响因子：
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通讯作者：
Theisen,EmilyR
中科院分区：
文献类型：
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作者：
Bayanjargal,Ariunaa;Taslim,Cenny;Showpnil,IftekharA;Selich-Anderson,Julia;Crow,JesseC;Lessnick,StephenL;Theisen,EmilyR
尤文肉瘤是儿童和年轻人中第二常见的骨癌。在85%的患者中，11号和22号染色体之间的易位导致一种有效的融合癌蛋白EWSR 1：：FLI 1。EWSR 1：：FLI 1是尤文肉瘤肿瘤基因组中唯一的遗传改变。蛋白质的EWSR 1部分是一个内在无序的结构域，参与EWSR 1：：FLI 1的转录调控。融合物的FLI部分含有显示结合核心GGAA基序和GGAA重复的DNA结合结构域。FLI 1的DNA结合结构域中的小α-螺旋，DBD-β4螺旋，对于EWSR 1：：FLI 1的转录功能至关重要。在这项研究中，我们的目的是了解DBD-β4螺旋促进转录的机制，从而致癌转化。我们利用多组学方法来评估在表达具有和不具有DBD-FLI 4螺旋的EWSR 1：：FLI 1构建体的细胞中的染色质组织、活性染色质标记、基因组结合和基因表达。𝛼我们的研究表明DBD-β4螺旋对于EWSR 1：：FLI 1在GGAA微卫星上的协同结合至关重要。这种结合是EWSR 1：：FLI 1基因组调控的许多方面的基础，例如TADs，染色质环，增强子和生产性转录中心的形成。
Ewing sarcoma is the second most common bone cancer in children and young adults. In 85% of patients, a translocation between chromosomes 11 and 22 results in a potent fusion oncoprotein, EWSR1::FLI1. EWSR1::FLI1 is the only genetic alteration in an otherwise unaltered genome of Ewing sarcoma tumors. The EWSR1 portion of the protein is an intrinsically disordered domain involved in transcriptional regulation by EWSR1::FLI1. The FLI portion of the fusion contains a DNA binding domain shown to bind core GGAA motifs and GGAA repeats. A small alpha-helix in the DNA binding domain of FLI1, DBD-𝛼4 helix, is critical for the transcription function of EWSR1::FLI1. In this study, we aimed to understand the mechanism by which the DBD-𝛼4 helix promotes transcription, and therefore oncogenic transformation. We utilized a multi-omics approach to assess chromatin organization, active chromatinmarks, genome binding, and gene expression in cells expressing EWSR1::FLI1 constructs with and without the DBD-𝛼4 helix. Our studies revealed DBD-𝛼4 helix is crucial for cooperative binding of EWSR1::FLI1 at GGAA microsatellites. This binding underlies many aspects of genome regulation by EWSR1::FLI1 such as formation of TADs, chromatin loops, enhancers and productive transcription hubs.