Nuclear export of different classes of RNA is mediated by specific factors.
Nuclear export of different classes of RNA is mediated by specific factors.
复制标题
DOI：
10.1083/jcb.124.5.627
复制
发表时间：
1994-03
期刊：
影响因子：
--
通讯作者：
Mattaj IW
中科院分区：
文献类型：
--
作者：
Jarmolowski A;Boelens WC;Izaurralde E;Mattaj IW
各种类型的RNA从细胞核输出到细胞质，包括RNA聚合酶I（大核糖体RNA）、II（富含U的小核RNA [U snRNA]，mRNA）和III（tRNA，5S RNA）的转录物。在这里，有证据表明，在出口的各种类别的核RNA的一些步骤是由特定的，而不是共同的因素介导的。使用显微注射到非洲爪蟾卵母细胞，它表明，tRNA，一个U snRNA，和mRNA竞争性地抑制自己的出口浓度，在这些浓度下，它们对异源RNA的出口没有影响。虽然U snRNA和mRNA的输出都被它们的7-甲基鸟苷帽结构增强，但发现识别这种结构的因子仅在U snRNA的情况下在浓度上受到限制。除了特定的因素，在输出过程中的步骤，可能是共同的至少一些类别的RNA的证据提供了实验中，合成的均聚RNA被用作抑制剂。
Various classes of RNA are exported from the nucleus to the cytoplasm, including transcripts of RNA polymerase I (large ribosomal RNAs), II (U- rich small nuclear RNAs [U snRNAs], mRNAs), and III (tRNAs, 5S RNA). Here, evidence is presented that some steps in the export of various classes of nuclear RNA are mediated by specific rather than common factors. Using microinjection into Xenopus oocytes, it is shown that a tRNA, a U snRNA, and an mRNA competitively inhibit their own export at concentrations at which they have no effect on the export of heterologous RNAs. While the export of both U snRNAs and mRNAs is enhanced by their 7-methyl guanosine cap structures, factors recognizing this structure are found to be limiting in concentration only in the case of U snRNAs. In addition to the specific factors, evidence for steps in the export process that may be common to at least some classes of RNA are provided by experiments in which synthetic homopolymeric RNAs are used as inhibitors.