U5 snRNP在前体mRNA剪接加工中的作用

Role of U5snRNP in pre-mRNA Splicing

前体mRNA的剪接是基因表达过程中的关键一步,发生在基因的转录之后与蛋白合成之前。在由前体mRNA剪接加工而形成成熟mRNA时,需要将转录本中的内含子切除,因为它会干扰基因的表达。前体mRNA的剪接发生在细胞核中,是在一个大的RNA与蛋白质的复合体即剪接体的催化下完成的。复合体中含有U1、U2、U5,二聚体形式的U4/U6小核RNA(snRNA)和一些小核核糖核蛋白(snRNP)。U5snRNP特异蛋白包括hPrp8,hSnu114(aGTPase),hBrr2(aDExH/Dboxhelicase)和Prp28等。Prp8构成剪接体的催化核心,hSnu114可避免剪接复合体过早的活化。因此,U5snRNP在剪接体聚集过程和前体mRNA的剪接反应中发挥重要作用。

Pre-messenger RNA （pre-mRNA） splicing is a key step in gene expression, occurring between transcription and protein synthesis. Pre-mRNA splicing removes intron sequences that otherwise disrupt the gene expression. This process takes place in the nucleus, catalyzed by a large RNA-protein complex called spliceosome. U5snRNP protein includes hPrpS, hSnu114, hBrr2 and Prp28, and plays an important role in spliceosome assembling and Pre-mRNA splicing.