Enhancer-dependent interaction between 5' and 3' splice sites in trans.
Splice-site selection and alternative splicing of nuclear pre-mRNAs can be controlled by splicing enhancers that act by promoting the activity of upstream splice sites. Here we show that RNA molecules containing a 3' splice site and enhancer sequence are efficiently spliced in trans to RNA molecules containing normally cis-spliced 5' splice sites or to normally trans-spliced spliced leader RNAs from lower eukaryotes. In addition, we show that this reaction is stimulated by (Ser + Arg)-rich splicing factors that are known to promote protein-protein interactions in the cis-splicing reaction. Thus, splicing enhancers facilitate the assembly of protein complexes on RNAs containing a 3' splice site, and this complex is sufficiently stable to functionally interact with 5' splice sites located on separate RNAs. This trans-splicing is mediated by interactions between (Ser + Arg)-rich splicing factors bound to the enhancer and general splicing factors bound to the 5' and 3' splice sites. These same interactions are likely to play a crucial role in alternative splicing and splice-site selection in cis.
Bruzik
J P
JP
Case Western Reserve University, Department of Molecular Biology and Microbiology, Cleveland, OH 44106, USA.
Maniatis
T
T
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D009687:Nuclear Proteins; D011485:Protein Binding; D012326:RNA Splicing; D012091:Repetitive Sequences, Nucleic Acid; D012261:Ribonucleoproteins / Q000378:metabolism; D000072668:Splicing Factor U2AF; D013329:Structure-Activity Relationship; D014351:Trypanosomatina / Q000235:genetics*
D009687:Nuclear Proteins; D012261:Ribonucleoproteins; D000072668:Splicing Factor U2AF