一个含有U11,U12和U5 snRNP的新型结合酶体在体外切除了一个小类 (AT-AC) 内子
1Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06536, USA.
Cell
|March 8, 1996
概括
研究人员在甲动物基因中发现了一小部分AT-AC内子. 使用HeLa细胞的体外系统准确地将这些内子结合在一起,揭示了AT-AC结合体中U12和U5小核核核蛋白蛋白 (snRNP) 的重要作用.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 在RNA分离过程中.
背景情况:
- 甲动物蛋白质编码基因中的一小部分内子利用非正规拼接位 (AT-AC) 和分支位序列.
- 这些AT-AC内子比正规内子少见,但在基因表达中起作用.
研究的目的:
- 建立一个体外系统来研究AT-AC内拼接.
- 阐明分子机制,并确定涉及AT-AC拼接的关键组件.
主要方法:
- 开发一种基于HeLa细胞的体外剪接系统,使用一种前mRNA基质与来自人类P120基因的AT-AC内突.
- 使用psoralen交叉链接,确认预测的分支部位相互作用.
- 使用本地凝电泳分析对拼接酶组合的分析.
- 通过寡核酸中介抑制对snRNP的功能评估.
主要成果:
- 建立的体外系统准确地拼接了P120的AT-AC内部.
- 拼接通过一个拉里亚特中间体进行,预计分支部位A残留物从含有U12小核核糖核蛋白 (snRNP) 的双重体中膨胀出来.
- U11,U12和U5 snRNP被证明可以在P120前mRNA上组装成拼接复合体.
- 抑制研究证实了U12和U5 snRNP在AT-AC结合体功能中的重要作用.
结论:
- 这项研究成功地描述了一种用于AT-AC内拼接的体外系统.
- U12和U5 snRNP是AT-AC拼接体的关键组成部分,参与非正规内子的拼接.
- 这项工作为管理替代拼接途径的机械和机制提供了洞察力.
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