An exon that prevents transport of a mature mRNA
AUTOR(ES)
MacMorris, Margaret A.
FONTE
The National Academy of Sciences
RESUMO
In Caenorhabditis elegans, pre-mRNA for the essential splicing factor U2AF65 sometimes is spliced to produce an RNA that includes an extra 216-bp internal exon, exon 3. Inclusion of exon 3 inserts an in-frame stop codon, yet this RNA is not subject to SMG-mediated RNA surveillance. To test whether exon 3 causes RNA to remain nuclear and thereby escape decay, we inserted it into the 3′ untranslated region of a gfp reporter gene. Although exon 3 did not affect accumulation or processing of the mRNA, it dramatically suppressed expression of green fluorescent protein (GFP). We showed by in situ hybridization that exon 3-containing gfp RNA is retained in the nucleus. Intriguingly, exon 3 contains 10 matches to the 8-bp 3′ splice-site consensus. We hypothesized that U2AF might recognize this octamer and thereby prevent export. This idea is supported by RNA interference experiments in which reduced levels of U2AF resulted in a small burst of gfp expression.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=22377Documentos Relacionados
- Exon repetition in mRNA
- The exon–exon junction complex provides a binding platform for factors involved in mRNA export and nonsense-mediated mRNA decay
- Parvovirus RNA transcripts containing sequences not present in mature mRNA: a method for isolation of putative mRNA precursor sequences.
- Mutational Analysis of an RNA Recognition Element That Mediates Localization of bicoid mRNA
- The spliceosome deposits multiple proteins 20–24 nucleotides upstream of mRNA exon–exon junctions