O-GlcNAcylation is involved in the transcriptional activity of EWS-FLI1 in Ewing's sarcoma.
O-GlcNAcylation is involved in the transcriptional activity of EWS-FLI1 in Ewing's sarcoma.
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DOI：
10.1038/onc.2008.484
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发表时间：
2009-03-05
期刊：
影响因子：
8
通讯作者：
Kovar H
中科院分区：
文献类型：
--
作者：
Bachmaier R;Aryee DN;Jug G;Kauer M;Kreppel M;Lee KA;Kovar H
癌基因EWS-FLI 1编码在尤文氏肉瘤家族肿瘤（ESFT）中表达的嵌合转录因子。EWS-FLI 1靶基因表达被认为驱动ESFT发病机制，因此，抑制EWS-FLI 1活性具有很高的治疗前景。由于许多转录因子的活性受翻译后修饰的调节，我们研究了EWS-FLI 1上修饰的存在。免疫纯化的融合蛋白被O-连接的β-N-乙酰葡糖胺化特异性抗体识别，并容易与磷蛋白特异性染料结合。抑制Ser/Thr特异性磷酸酶增加EWS-FLI 1分子量并降低其O-GlcNAc含量，表明EWS-FLI 1的磷酸化和O-GlcNAc化动态相互作用。通过突变分析，O-GlcNAc化被描绘为氨基末端EWS转录激活结构域的Ser/Thr残基。己糖胺生物合成途径的代谢抑制消除了EWS-FLI 1的O-GlcNAc酰化，并特异性干扰了EWS-FLI 1靶标Id 2的转录激活。这些结果表明，调节EWS-FLI 1糖基化的药物在功能上干扰其活性，因此可能构成对当前ESFT化疗的有希望的补充。
The oncogene EWS-FLI1 encodes a chimeric transcription factor expressed in Ewing’s sarcoma family tumors (ESFT). EWS-FLI1 target gene expression is thought to drive ESFT pathogenesis and, therefore, inhibition of EWS-FLI1 activity holds high therapeutic promise. Since the activity of many transcription factors is regulated by post-translational modifications, we studied the presence of modifications on EWS-FLI1. The immuno-purified fusion-protein was recognized by an antibody specific for O-linked β-N-acetylglucosaminylation, and readily bound to a phosphoprotein-specific dye. Inhibition of Ser/Thr specific phophatases increased EWS-FLI1 molecular weight and reduced its O-GlcNAc content, suggesting that phosphorylation and O-GlcNAcylation of EWS-FLI1 dynamically interact. By mutation analysis, O-GlcNAcylation was delineated to Ser/Thr residues of the amino-terminal EWS transcriptional-activation domain. Metabolic inhibition of the hexosamine biosynthetic pathway abrogated O-GlcNAcylation of EWS-FLI1 and specifically interfered with transcriptional activation of the EWS-FLI1 target Id2. These results suggest that drugs modulating glycosylation of EWS-FLI1 functionally interfere with its activity and might therefore constitute promising additions to current ESFT chemotherapy.