Exon Junction Complexes can have distinct functional flavours to regulate specific splicing events

Zhen Wang,Hervé Le Hir,Isabelle Barbosa,Lionel Ballut

doi:10.1038/s41598-018-27826-y

Abstract

The exon junction complex (EJC) deposited on spliced mRNAs, plays a central role in the post-transcriptional gene regulation and specific gene expression. The EJC core complex is associated with multiple peripheral factors involved in various post-splicing events. Here, using recombinant complex reconstitution and transcriptome-wide analysis, we showed that the EJC peripheral protein complexes ASAP and PSAP form distinct complexes with the EJC core and can confer to EJCs distinct alternative splicing regulatory activities. This study provides the first evidence that different EJCs can have distinct functions, illuminating EJC-dependent gene regulation.

Highlights

The Exon Junction Complex (EJC) plays a central role in post-transcriptional gene expression control
To determine how the ASAP complex interacts with the exon junction complex (EJC) core, we performed in vitro coprecipitation assays[3] with Tandem Affinity Purification (TAP)-tagged recombinant proteins corresponding to full-length human SAP18, RNPS1 and ACINUS
Individual ASAP proteins were incubated with recombinant EJC core proteins either in the presence or absence of single-stranded RNA (ssRNA) and ADPNP

Summary

Results and Discussion

ACINUS bridges the ASAP complex to the EJC core. To determine how the ASAP complex interacts with the EJC core, we performed in vitro coprecipitation assays[3] with Tandem Affinity Purification (TAP)-tagged recombinant proteins corresponding to full-length human SAP18, RNPS1 and ACINUS. The reconstitution of a stable EJC core requires single-stranded RNA (ssRNA) and ATP (or its non-hydrolysable form, ADPNP), and in the absence of either, the complex is not formed[3]. Individual ASAP proteins were incubated with recombinant EJC core proteins either in the presence or absence of ssRNA and ADPNP. We could test whether individual ASAP proteins interact with EJC core components individually or with the EJC core complex.

EJC core precipitate

Methods

Ctr ACIN Ctr ACIN

Author Contributions

Additional Information