Trans-splicing of nematode premessenger RNA.
In nematodes, many mRNAs contain a common 5' terminal 22-nt sequence. This sequence, the spliced leader (SL), is acquired from a small (approximately 100 nt) SL RNA via trans-splicing. Parallel in vitro and in vivo experiments have begun to clarify both the mechanism and biological role of trans-splicing. In vitro analysis (in cell free extracts) has shown that trans-splicing is remarkably similar to the snRNP mediated removal of intervening sequences from pre-mRNAs (cis-splicing). Additionally, this analysis has suggested a mechanism that may explain how the two substrates of trans-splicing (the SL RNA and pre-mRNA) efficiently associate with one another in the absence of sequence complementarity. In vivo experiments suggest that a major biological function of trans-splicing in nematodes may be to process polycistronic transcription units. Results obtained from the study of both parasitic and free-living species are discussed, and trans-splicing in nematodes is compared and contrasted to the analogous process in trypanosomatid protozoans.
Nilsen
T W
TW
Department of Molecular Biology, and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106.
D000818:Animals; D001483:Base Sequence; D008969:Molecular Sequence Data; D009348:Nematoda / Q000235:genetics*; D012322:RNA Precursors / Q000378:metabolism; D012326:RNA Splicing
D012322:RNA Precursors