A conserved intronic U1 snRNP-binding sequence promotes trans-splicing in Drosophila.
Genes Dev
; 29(7): 760-71, 2015 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-25838544
ABSTRACT
Unlike typical cis-splicing, trans-splicing joins exons from two separate transcripts to produce chimeric mRNA and has been detected in most eukaryotes. Trans-splicing in trypanosomes and nematodes has been characterized as a spliced leader RNA-facilitated reaction; in contrast, its mechanism in higher eukaryotes remains unclear. Here we investigate mod(mdg4), a classic trans-spliced gene in Drosophila, and report that two critical RNA sequences in the middle of the last 5' intron, TSA and TSB, promote trans-splicing of mod(mdg4). In TSA, a 13-nucleotide (nt) core motif is conserved across Drosophila species and is essential and sufficient for trans-splicing, which binds U1 small nuclear RNP (snRNP) through strong base-pairing with U1 snRNA. In TSB, a conserved secondary structure acts as an enhancer. Deletions of TSA and TSB using the CRISPR/Cas9 system result in developmental defects in flies. Although it is not clear how the 5' intron finds the 3' introns, compensatory changes in U1 snRNA rescue trans-splicing of TSA mutants, demonstrating that U1 recruitment is critical to promote trans-splicing in vivo. Furthermore, TSA core-like motifs are found in many other trans-spliced Drosophila genes, including lola. These findings represent a novel mechanism of trans-splicing, in which RNA motifs in the 5' intron are sufficient to bring separate transcripts into close proximity to promote trans-splicing.
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Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
RNA Nuclear Pequeno
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Splicing de RNA
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Trans-Splicing
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Drosophila
Limite:
Animals
Idioma:
En
Revista:
Genes Dev
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2015
Tipo de documento:
Article