Identification of core components of the exon junction complex in trypanosomes.
In animal cells, the exon junction complex (EJC) is deposited onto mRNAs during the second step of splicing, 20-24 nt 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.
Bercovich
Natalia
N
INGEBI-CONICET, Vuelta de Obligado 2490, 2P, Buenos Aires, Argentina.
Levin
Mariano J
MJ
Clayton
Christine
C
Vazquez
Martin P
MP
D000595:Amino Acid Sequence; D000818:Animals; D005091:Exons; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012326:RNA Splicing; D034443:RNA Transport; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014346:Trypanosoma brucei brucei / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014352:Trypanosomiasis / Q000469:parasitology*
D015800:Protozoan Proteins; D016601:RNA-Binding Proteins