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与E2F1-DP1结合的Rb C终端域的结构:酸化诱导的E2F释放机制
Seth M Rubin1, Anne-Laure Gall, Ning Zheng
1Structural Biology Program and Howard Hughes Medical Institute, Memorial Sloan-Kettering Cancer Center, NY 10021, USA.
Cell
|December 20, 2005
概括
视网膜母细胞瘤 (Rb) 蛋白质
科学领域:
- 细胞周期调节细胞周期调节
- 分子生物学分子生物学
- 蛋白质与蛋白质之间的相互作用
背景情况:
- 视网母细胞瘤 (Rb) 蛋白质是细胞周期中G1-S阶段过渡的关键调节者.
- Rb与E2F转录因子结合,抑制它们的活性,直到被循环林依赖性激酶酸化.
- 虽然Rb口袋域调解E2F结合,但C端域 (RbC) 也对增长抑制至关重要.
研究的目的:
- 阐明Rb C-终端域 (RbC) 和E2F-DP异构体之间的相互作用的结构基础.
- 了解RbC在高亲和度E2F结合和生长抑制中的作用.
- 研究酸化调节Rb-E2F相互作用的机制.
主要方法:
- 同免疫沉降测定以确认蛋白质相互作用.
- 进行X射线晶体学以确定RbC-E2F1-DP1复合物的结构.
- 位点定向突变发生,研究酸化对Rb-E2F结合的影响.
主要成果:
- 确定了RbC和E2F-DP异构体之间的高亲和相互作用.
- 晶体结构显示了一个交织的异构体,其中E2F1和DP1标记的盒子域与RbC接触.
- 在特定位置 (Ser788/795和Thr821/826) 化RbC被证明可以通过直接和间接的机制破坏Rb-E2F相互作用的稳定性.
结论:
- Rb C终端域 (RbC) 对于与E2F-DP异构体的高亲和结合至关重要,并有助于增长抑制.
- 晶体结构为RbC-E2F-DP复合体形成提供了分子基础.
- 化RbC作为调节开关,调节Rb-E2F协会,从而控制细胞循环的进展.
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