Polypurine sequences within a downstream exon function as a splicing enhancer
- Kyoto Univ. (Japan)
We have previously shown that a purine-rich sequence located within exon M2 of the mouse immunoglobulin {mu} gene functions as a splicing enhancer, as judged by its ability to stimulate splicing of a distant upstream intron. This sequence element has been designated ERS (exon recognition sequence). In this study, we investigated the stimulatory effects of various ERS-like sequences, using the in vitro splicing system with HeLa cell nuclear extracts. Here, we show that purine-rich sequences of several natural exons that have previously been shown to be required for splicing function as a splicing enhancer like the ERS of the immunoglobulin {mu} gene. Moreover, even synthetic polypurine sequences had stimulatory effects on the upstream splicing. Evaluation of the data obtained from the analyses of both natural and synthetic purine-rich sequences shows that (i) alternating purine sequences can stimulate splicing, while poly(A) or poly(G) sequences cannot, and (ii) the presence of U residues within the polypurine sequence greatly reduces the level of stimulation. Competition experiments strongly suggest that the stimulatory effects of various purine-rich sequences are mediated by the same trans-acting factor(s). We conclude from these results that the purine-rich sequences that we examined in this study also represent examples of ERS. Thus, ERS is considered a general splicing element that is present in various exons and plays an important role in splice site selection. 50 refs., 7 figs., 2 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 577143
- Journal Information:
- Molecular and Cellular Biology, Vol. 14, Issue 2; Other Information: PBD: Feb 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
Modulation of splicing of the preceding intron by antisense oligonucleotide complementary to intra-exon sequence deleted in dystrophin Kobe
The length of the downstream exon and the substitution of specific sequences affect pre-mRNA splicing in vitro