通过多价值Rap1相互作用,Rif1和Rif2通过多价值Rap1相互作用来塑造端粒的功能和结构.
Tianlai Shi1, Richard D Bunker, Stefano Mattarocci
1Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
Cell
|June 11, 2013
概括
酵母端粒受到端粒的保护,端粒是一个由Rap1,Rif1和Rif2蛋白质组成的复合体. 这项研究揭示了Rif1和Rif2如何创建稳定Rap1的更高阶结构,确保端粒长度的稳定性.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 酵母端粒由TG1−3重复组成,并由转录因子Rap1.1结合.
- 端粒由Rap1,Rif1和Rif2组成,形成端粒的保护帽,调节端粒酶,沉默和DNA断裂反应.
研究的目的:
- 为了阐明酵母细胞的分子结构.
- 了解Rif1和Rif2的Rap1招募和稳定结构的基础.
主要方法:
- 进行X射线晶体学以确定与Rap1.1结合的Rif1和Rif2的结构.
- 生物化学和功能测试来剖析蛋白质相互作用和端粒恒常性.
主要成果:
- 晶体结构揭示了Rif1和Rif2上独立的Rap1结合点,使长距离相互作用成为可能.
- Rif1四聚化和Rif2聚合模块为连接Rap1单元的更高阶架构做出了贡献.
- 这种"分子带"机制对于在端粒上招募和稳定Rap1至关重要,从而维持端粒平衡.
结论:
- Rif1和Rif2形成了一个高阶结构,通过长距离相互作用稳定了酵母端粒中的Rap1.
- 这种机制对于维持体内端粒长度和整体端粒恒温是必不可少的.
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