In:
Genes & Development, Cold Spring Harbor Laboratory, Vol. 29, No. 7 ( 2015-04-01), p. 760-771
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.
Type of Medium:
Online Resource
ISSN:
0890-9369
,
1549-5477
DOI:
10.1101/gad.258863.115
Language:
English
Publisher:
Cold Spring Harbor Laboratory
Publication Date:
2015
detail.hit.zdb_id:
1467414-2
SSG:
12
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