Bruzik J P, Maniatis T
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Nature. 1992 Dec 17;360(6405):692-5. doi: 10.1038/360692a0.
Exon sequences present on separate RNA molecules can be joined by trans-splicing in trypanosomatids, Euglena, and in the nematode and trematode worms. Trans-splicing involves an interaction between a 5' splice site present in a spliced leader RNA and a 3' splice site located near the 5' end of pre-messenger RNAs. In vitro trans-splicing of artificial mammalian pre-mRNAs has been reported, but the efficiency of splicing appears to depend on sequence complementarity between the two substrates. There has been speculation that some natural pre-mRNAs can be trans-spliced in mammalian cells in vivo, but alternative interpretations have not been ruled out. Here we show that spliced leader RNAs can be accurately trans-spliced in mammalian cells in vivo and in vitro. Both nematode and mammalian 3' splice sites can function as acceptors for trans-splicing in vivo. These results reveal functional conservation in the splicing machinery between lower eukaryotes and mammals, and they directly demonstrate the potential for trans-splicing in mammalian cells.
存在于不同RNA分子上的外显子序列可通过反式剪接在锥虫、眼虫以及线虫和吸虫中连接起来。反式剪接涉及剪接前导RNA中存在的5'剪接位点与位于信使前体RNA 5'端附近的3'剪接位点之间的相互作用。已有报道称人工哺乳动物信使前体RNA可进行体外反式剪接，但剪接效率似乎取决于两种底物之间的序列互补性。有人推测一些天然信使前体RNA在体内哺乳动物细胞中可进行反式剪接，但其他解释尚未排除。在此我们表明，剪接前导RNA在体内和体外的哺乳动物细胞中均可准确进行反式剪接。线虫和哺乳动物的3'剪接位点在体内均可作为反式剪接的受体。这些结果揭示了低等真核生物和哺乳动物剪接机制中的功能保守性，并直接证明了哺乳动物细胞中反式剪接的潜力。
