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. 1988 Aug;7(8):2539–2545. doi: 10.1002/j.1460-2075.1988.tb03102.x

Physical identification of branched intron side-products of splicing in Trypanosoma brucei.

D Ralph 1, J Huang 1, L H Van der Ploeg 1
PMCID: PMC457125  PMID: 3191913

Abstract

Every mRNA in trypanosomes consists of two exons, a common 5' capped mini-exon or spliced leader and a coding-exon. All evidence suggests that the exons are joined by trans-splicing of two individual precursor RNAs, the mini-exon donor RNA or spliced leader precursor RNA (medRNA) and the pre-mRNA. We studied intermediates of the splicing reaction using denaturing two-dimensional PAGE and structurally identified a group of small (approximately 180-300 nt) non-polyadenylated, Y-shaped branched RNAs. The branched Y-shaped RNAs contain the 105 nt medRNA derived intron, joined in a 2'-5' phosphodiester bond to small heterogeneously sized RNAs. These non-polyadenylated branched Y-shaped RNA molecules are analogous to the lariat shaped introns of higher eukaryotes and presumably represent the released intron-like by-products of a trans-splicing reaction which joins the mini-exon and the major coding-exon.

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Selected References

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