@article{leverette_andrews_maxwell_1992, title={MOUSE U14 SNRNA IS A PROCESSED INTRON OF THE COGNATE HSC70 HEAT-SHOCK PREMESSENGER RNA}, volume={71}, ISSN={["0092-8674"]}, DOI={10.1016/S0092-8674(05)80069-8}, abstractNote={U14 snRNA is a small nucleolar RNA species essential for eukaryotic pre-rRNA processing. We have previously shown that the mouse U14 snRNA genes are positioned within introns 5, 6, and 8 on the coding strand of the constitutively expressed cognate hsc70 heat shock gene. This genomic organization suggested the possibility that U14 snRNAs are transcribed as part of the hsc70 pre-mRNA and then excised from the intron to yield mature U14 snRNA species. To test this hypothesis directly, we have microinjected Xenopus oocytes with hsc70 pre-mRNA transcripts possessing intron 5 and the encoded U14 snRNA sequence. Processing results demonstrate that, in addition to the splicing of upstream and downstream exons, a mature 87 nt U14 snRNA is excised from the intron. Accurate excision of U14 snRNA from hsc70 intron 5 can occur in the absence of splicing. These results demonstrate a biosynthetic pathway for an snRNA species and provide a novel example of a eukaryotic pre-mRNA intron that is processed to produce a stable, biologically functional RNA species.}, number={7}, journal={CELL}, author={LEVERETTE, RD and ANDREWS, MT and MAXWELL, ES}, year={1992}, month={Dec}, pages={1215–1221} }