Spliced leader RNA

Spliced leader RNA trans-splicing is a form of RNA editing in which a short RNA exon (the... 

Table 2.5. Platyhelminth spliced leader RNAs/genes.

Davis, R.E. (1997) Surprising diversity and distribution of spliced leader RNAs in flatworms. Molecular and Biochemical Parasitology 87, 29—48. 

Stratford, R. and Shields, R. (1 994) A frans-spliced leader RNA sequence in plant parasitic nematodes. Molecular and Biochemical Parasitology 67, 147-1 55. 

Mechanism of Trans-Splicing the Spliced-Leader RNAs... 

Perry K, A bian N. mRNA processing in the Ttypanosomatidae. Experientia 1991 47 118-128. Das A, Zhang Q, Palenchar JB et al. Trypanosomal TBP functions with the multisubunit transcription factor tSNAP to direct spliced-leader RNA gene expression. Mol Cell Biol 2005 ... 

Schitnanski B, Nguyen TN, Gunzl A. Characterization of a multisubunit transcription ctor complex essential for spliced-leader RNA gene transcription in Trypanosoma brucei. Mol Cell Biol 2005 25(16) 7303-7313. 

Schimanski B, Brandenbu J. Nguyen TN et al. A TFIIB-like protein is indispensable for spliced leader RNA gene transcription in Trypanosoma brucei. NucI Acids Res 2006 34(6) 1676-1684. Anantharaman V, Aravind L, Koonin EV. Emergence of diverse biochemical activities in evolutionarily conserved structural scaffolds of proteins. Curr Opin Chem Biol 2003 7(l) 12-20. Clayton CE. Life without ttanscriptional control From fly to man and back ain. EMBO J 2002 21(8) 1881-1888. 

Bruzik, J.P. Maniatis, T. (1992) Nature (London) 360, 692-695. Spliced leader RNAs from lower eukaryotes are frans-spliced in mammalian cells. 

Davis, R.E., Singh, H., Botka, C., Hardwick, C., Ashraf el Meanawy, M. and Villanueva, J. (1994) RNA transsplicing in Fasciola hepatica. Identification of a spliced leader (si) RNA and si sequences on mRNAs. Journal of Biological Chemistry 269, 20026-20030. 

In addition to providing a discrete 5 end for mRNAs, trans-splicing also provides each mRNA with the cap structure derived from the SL RNA. Although it remains to be established whether translation in trypanosomes or nematodes is cap dependent, it seems likely that the cap, as it is in other eukaryotes, will be essential for mRNA recognition by ribosomes. It remains to be determined whether spliced leader or cap addition is necessary for transport of mRNAs from the nucleus or influences mRNA stability. 

Nascently transcribed eukaryotic iRNAs are among the most processed of all RNA polymerase III transcripts. Like those of prokaryotic tRNAs, the 5 leader is cleaved by RNase P, the 3 trailer is removed, and CCA is added by the CCA-adding enzyme (Figure 29.25). Eukaryotic tRNAs are also heavily modified on base and ribose moieties these modifications are important for function. In contrast with prokaryotic tRNAs, many eukaryotic pre-tRNAs are also spliced by an endonuclease and a ligase to remove an intron. 

Ghosh, P. K., Piatak, M., Mertz, J. E., Weissman, S. M., and Lebowitz, P., 1982, Altered utilization of splice sites and 5 termini in late RNAs produced by leader region mutants of SV40, J. Virol. 44 610-624. 

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