Format

Send to

Choose Destination
Cell. 2012 Nov 9;151(4):750-64. doi: 10.1016/j.cell.2012.10.007. Epub 2012 Oct 18.

The cellular EJC interactome reveals higher-order mRNP structure and an EJC-SR protein nexus.

Author information

1
Howard Hughes Medical Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA.

Erratum in

  • Cell. 2012 Nov 9;151(4):915-6.

Abstract

In addition to sculpting eukaryotic transcripts by removing introns, pre-mRNA splicing greatly impacts protein composition of the emerging mRNP. The exon junction complex (EJC), deposited upstream of exon-exon junctions after splicing, is a major constituent of spliced mRNPs. Here, we report comprehensive analysis of the endogenous human EJC protein and RNA interactomes. We confirm that the major "canonical" EJC occupancy site in vivo lies 24 nucleotides upstream of exon junctions and that the majority of exon junctions carry an EJC. Unexpectedly, we find that endogenous EJCs multimerize with one another and with numerous SR proteins to form megadalton sized complexes in which SR proteins are super-stoichiometric to EJC core factors. This tight physical association may explain known functional parallels between EJCs and SR proteins. Further, their protection of long mRNA stretches from nuclease digestion suggests that endogenous EJCs and SR proteins cooperate to promote mRNA packaging and compaction.

PMID:
23084401
PMCID:
PMC3522173
DOI:
10.1016/j.cell.2012.10.007
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center