The Drosophila U1-70K protein is required for viability, but its arginine-rich domain is dispensable
The Drosophila U1-70K protein is required for viability, but its arginine-rich domain is dispensable
复制标题
DOI：
10.1534/genetics.104.032532
复制
发表时间：
2004-12-01
期刊：
影响因子：
3.3
通讯作者：
Mount, SM
中科院分区：
文献类型：
--
作者：
Salz, HK;Mancebo, RSY;Mount, SM
保守的剪接体 U1-70K 蛋白被认为通过将 U1 snRNP 颗粒与调节性 RNA 结合蛋白连接而在 RNA 剪接中发挥关键作用。尽管这些蛋白质相互作用在体外是由富含精氨酸和丝氨酸（RS 结构域）的重复单元介导的，但尚未对该结构域在完整多细胞生物体中的重要性进行测试。在这里，我们报告了果蝇中 U1-70K 功能的全面通用分析。与 U1-70K 是重要剪接因子的观点一致，我们发现 U1-70K 功能的丧失会导致胚胎发生过程中的致死性。令人惊讶的是，与目前对 U1-70K 功能的看法相反，携带缺乏富含精氨酸结构域（包括两组嵌入的 RS 二肽重复序列）的突变 U1-70K 蛋白的动物没有可辨别的突变表型。然而，通过双突变研究，我们表明，当与另一个 U1 snRNP 组件中的可行突变结合时，U1-70K RS 结构域删除不再支持活力。我们的研究共同证明，虽然 U1-70K RS 结构域介导的蛋白质相互作用对于生存能力不是必需的，但它们仍然有助于 U1 snRNP 的基本功能。
The conserved spliceosomal U1-70K protein is thought to play a key role in RNA Splicing by linking the U1 snRNP particle to regulatory, RNA-binding proteins. Although these protein interactions are mediated by repeating units rich in arginines and serines (RS domains) in vitro, tests of this domain's importance in intact multicellular organisms have not been carried out. Here we report a comprehensive generic analysis of U1-70K function in Drosophila. Consistent with the idea that U1-70K is an essential splicing factor, we find that loss of U1-70K function results in lethality during embryogenesis. Surprisingly, and contrary to the current view of U1-70K function, animals carrying a mutant U1-70K protein lacking the arginine-rich domain, which includes two embedded sets of RS dipeptide repeats, have no discernible mutant phenotype. Through double-mutant studies, however, we show that the U1-70K RS domain deletion no longer supports viability when combined with a viable mutation in another U1 snRNP component. Together our studies demonstrate that while the protein interactions mediated by the U1-70K RS domain are not essential for viability, they nevertheless contribute to an essential U1 snRNP function.