从一个主办方的分离站点进行c-Myb-C/EBPβ合作的机制
Tahir H Tahirov1, Ko Sato, Emi Ichikawa-Iwata
1Kanagawa Academy of Science and Technology, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan. tahir@med.yokohama-cu.ac.jp
Cell
|January 17, 2002
概括
细胞髓母细胞瘤 (c-Myb) 转录因子与C/EBPβ合作调节基因表达,与其病毒对应物 (v-Myb) 不同. 结构分析揭示了一个关键的相互作用,使这种功能差异成为可能.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 基因规则 基因规则
背景情况:
- 细胞髓母细胞瘤 (c-Myb) 和鸟类髓母细胞瘤病毒 (AMV) v-Myb是参与髓母细胞基因调节的转录因子.
- c-Myb,但不是v-Myb,与C/EBPβ合作,激活骨髓特异性基因的转录.
- 这种功能差异的结构基础仍然不清楚.
研究的目的:
- 阐明c-Myb和C/EBP beta之间的差异性合作背后的结构机制.
- 为了比较c-Myb/C/EBPβ和v-Myb/C/EBPβ复合物的相互作用接口.
主要方法:
- 涉及c-Myb或v-Myb,C/EBPβ DBD和促进体DNA的DNA结合域 (DBDs) 的复合体的确定晶体结构.
- 使用GST拉下测试来确认蛋白质与蛋白质的相互作用.
- 进行光酶转激活测试以评估转录活性.
- 使用原子力显微镜可视化DNA循环和远程相互作用.
主要成果:
- 晶体结构显示,在c-Myb复合体中,与DNA结合的C/EBPβ与与单独的DNA片段结合的c-Myb的R2区域相互作用.
- 在v-Myb R2区域的点突变取消了v-Myb复合体中的这种相互作用.
- GST下拉和光酶试验证实了c-Myb/C/EBPβ相互作用的功能意义.
- 原子力显微镜表明,观察到的晶体相互作用模仿了促进子上的远程相互作用,涉及DNA循环.
结论:
- c-Myb的R2区域对于其与C/EBPβ的合作相互作用至关重要.
- 这种相互作用促进了长距离的DNA循环,使得髓质基因的转录调节得到了增强.
- 由于R2中的突变,v-Myb无法与C/EBPβ有效相互作用,这解释了它缺乏合作.
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