Identification of core components of the exon junction complex in trypanosomes

• Published in: Molecular and biochemical parasitology 2009-08, Vol.166 (2), p.190-193
• Main Authors: Bercovich, Natalia, Levin, Mariano J., Clayton, Christine, Vazquez, Martin P.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; EJC; Exons; Humans; Mago; Molecular Sequence Data; mRNA export; Protein Binding; Protozoan Proteins - chemistry; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; RNA Splicing; RNA Transport; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Sequence Alignment; Trypanosoma brucei brucei - chemistry; Trypanosoma brucei brucei - genetics; Trypanosoma brucei brucei - metabolism; Trypanosoma cruzi - chemistry; Trypanosoma cruzi - genetics; Trypanosoma cruzi - metabolism; Trypanosomes; Trypanosomiasis - parasitology; Y14
• ISSN: 0166-6851; 1872-9428
• DOI: 10.1016/j.molbiopara.2009.03.008

In animal cells, the exon junction complex (EJC) is deposited onto mRNAs during the second step of splicing, 20–24nt upstream of the exon–exon junction. The EJC core contains four proteins: Mago, Y14, eIF4AIII and Btz. In trypanosomes, cis-splicing is very rare but all mRNAs are subject to 5′trans-splicing of a 39-nt RNA sequence. Here we show that trypanosomes have a conserved Mago and a divergent Y14 protein, but we were unable to identify a Btz orthologue. We demonstrate that Mago and Y14 form a stable heterodimer using yeast two hybrid analyses. We also show that this complex co-purifies in vivo in trypanosomes with a protein containing an NTF2 domain, typically involved in mRNA transport.