单甲基化帽结构促进RNA从细胞核输出。

Monomethylated cap structures facilitate RNA export from the nucleus.

作者信息

Hamm J, Mattaj I W

机构信息

European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.

出版信息

Cell. 1990 Oct 5;63(1):109-18. doi: 10.1016/0092-8674(90)90292-m.

DOI:10.1016/0092-8674(90)90292-m

PMID:2208274

Abstract

RNA export from the nucleus has been analyzed in Xenopus oocytes. U1 snRNAs made by RNA polymerase II were exported into the cytoplasm, while U1 snRNAs synthesized by RNA polymerase III, and therefore with a different cap structure, remained in the nucleus. Export of the polymerase II-transcribed RNAs was inhibited by the cap analog m7GpppG. Spliced mRNAs carrying monomethylguanosine cap structures were rapidly exported, while hypermethylated cap structures delayed mRNA export. The export of a mutant precursor mRNA unable to form detectable splicing complexes was also significantly delayed by incorporation of a hypermethylated cap structure. The results suggest that the m7GpppN cap structure is likely to be a signal for RNA export from the nucleus.

摘要

已经在非洲爪蟾卵母细胞中分析了RNA从细胞核的输出。由RNA聚合酶II产生的U1 snRNAs被输出到细胞质中，而由RNA聚合酶III合成的、因此具有不同帽结构的U1 snRNAs则保留在细胞核中。聚合酶II转录的RNAs的输出被帽类似物m7GpppG抑制。携带单甲基鸟苷帽结构的剪接mRNA迅速输出，而超甲基化帽结构则延迟mRNA输出。通过掺入超甲基化帽结构，无法形成可检测剪接复合物的突变前体mRNA的输出也显著延迟。结果表明，m7GpppN帽结构可能是RNA从细胞核输出的信号。