Ideue Takashi, Sasaki Yasnory T F, Hagiwara Masatoshi, Hirose Tetsuro
Biological Information Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Koto-Ku, Tokyo 135-0064, Japan.
Genes Dev. 2007 Aug 15;21(16):1993-8. doi: 10.1101/gad.1557907. Epub 2007 Aug 3.
Pre-mRNA splicing specifically deposits the exon junction complex (EJC) onto spliced mRNA, which is important for downstream events. Here, we show that EJC components are primarily recruited to the spliceosome by association with the intron via the intron-binding protein, IBP160. This initial association of EJC components occurs in the absence of the final EJC-binding site on the exon. RNA interference (RNAi) knockdown of IBP160 arrested EJC association with cytoplasmic RNAs following nonsense-mediated decay. We propose that the intron has a crucial role in the early steps of EJC formation and is indispensable for the subsequent formation of a functional EJC.
前体mRNA剪接特异性地将外显子连接复合体（EJC）沉积到剪接后的mRNA上，这对下游事件很重要。在此，我们表明EJC组分主要通过与内含子结合蛋白IBP160结合而与内含子关联，从而被招募到剪接体上。EJC组分的这种初始关联发生在外显子上最终EJC结合位点缺失的情况下。RNA干扰（RNAi）敲低IBP160会阻止EJC在无义介导的衰变后与细胞质RNA的关联。我们提出，内含子在EJC形成的早期步骤中起关键作用，并且对于随后功能性EJC的形成不可或缺。
