在spliceosome的催化激活过程中重塑小核核核糖核蛋白
Evgeny M Makarov1, Olga V Makarova, Henning Urlaub
1Department of Cellular Biochemistry, Max Planck Institute of Biophysical Chemistry, D-37077 Göttingen, Germany.
概括
剪切酶激活涉及U5小核核核蛋白 (snRNP) 颗粒的重大结构变化. 这些动态重组涉及蛋白质组成的变化和前后预先信使RNA (预先mRNA) 拼接前后的重塑.
科学领域:
- 分子生物学分子生物学
- 在RNA生物学,RNA生物学.
- 蜂机械 蜂机械 蜂机械
背景情况:
- 剪接酶激活之前的前传递 RNA (前mRNA) 剪接,涉及显著的结构重组.
- 虽然已知小核RNA (snRNA) 的构造变化,但激活过程中的U5小核核核糖核蛋白 (snRNP) 的结构改造仍然不明.
研究的目的:
- 为了研究在激活过程中人类结合酶体的结构和蛋白质组成的变化.
- 在结合体激活和催化过程中描述U5 snRNP组件.
主要方法:
- 免疫亲和选择被用来分离人类的45S激活结合酶和一个新的35S U5 snRNP.
- 质谱法被用来分析这些孤立复合物的蛋白质成分.
主要成果:
- 在比较不同的snRNP和结合体复合体时,在结合体激活过程中观察到蛋白质组成的显著变化.
- U5 snRNP经历了剧烈的重塑,与Prp19复合体和其他因素密切相关,可能会交换其他U5蛋白质.
- 重塑后的U5 snRNP在拼接催化后以35S颗粒的形式释放.
结论:
- 剪切酶激活的特点是,在snRNP中,蛋白质组成发生了实质性的变化.
- 在结合体激活过程中,U5 snRNP被动态重塑,并在结合体组件的催化后释放中发挥作用.
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