title: The exon junction complex is required for definition and excision of neighboring introns in Drosophila.
abstract: Splicing of pre-mRNAs results in the deposition of the exon junction complex (EJC) upstream of exon-exon boundaries. The EJC plays crucial post-splicing roles in export, translation, localization, and nonsense-mediated decay of mRNAs. It also aids faithful splicing of pre-mRNAs containing large introns, albeit via an unknown mechanism. Here, we show that the core EJC plus the accessory factors RnpS1 and Acinus aid in definition and efficient splicing of neighboring introns. This requires prior deposition of the EJC in close proximity to either an upstream or downstream splicing event. If present in isolation, EJC-dependent introns are splicing-defective also in wild-type cells. Interestingly, the most affected intron belongs to the piwi locus, which explains the reported transposon desilencing in EJC-depleted Drosophila ovaries. Based on a transcriptome-wide analysis, we propose that the dependency of splicing on the EJC is exploited as a means to control the temporal order of splicing events.
authors: Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), 1030 Vienna, Austria;
authors: Rippei
authors: R
authors: Hayashi
authors: Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), 1030 Vienna, Austria;
authors: Dominik
authors: D
authors: Handler
authors: MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, United Kingdom.
authors: David
authors: D
authors: Ish-Horowicz
authors: Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), 1030 Vienna, Austria; julius.brennecke@imba.oeaw.ac.at.
authors: Julius
authors: J
authors: Brennecke
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000235:genetics; D002478:Cells, Cultured; D004251:DNA Transposable Elements / Q000235:genetics; D004330:Drosophila / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D020868:Gene Silencing; D007438:Introns / Q000235:genetics*; D010053:Ovary / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism; D012326:RNA Splicing / Q000502:physiology*
chemical_list: D060565:Argonaute Proteins; D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D012322:RNA Precursors; C116498:piwi protein, Drosophila
keywords: Piwi–piRNA pathway; SR proteins Acinus and RnpS1; exon junction complex; intron definition; splicing; transposon silencing