Giorgi C, et al. (2001) Release of U18 snoRNA from its host intron requires interaction of Nop1p with the Rnt1p endonuclease. EMBO J 20(23):6856-65
Abstract: An external stem, essential for the release of small nucleolar RNAs (snoRNAs) from their pre-mRNAs, flanks the majority of yeast intron-encoded snoRNAs. Even if this stem is not a canonical Rnt1p substrate, several experiments have indicated that the Rnt1p endonuclease is required for snoRNA processing. To identify the factors necessary for processing of intron-encoded snoRNAs, we have raised in vitro extracts able to reproduce such activity. We found that snoRNP factors are associated with the snoRNA- coding region throughout all the processing steps, and that mutants unable to assemble snoRNPs have a processing-deficient phenotype. Specific depletion of Nop1p completely prevents U18 snoRNA synthesis, but does not affect processing of a dicistronic snoRNA-coding unit that has a canonical Rnt1p site. Correct cleavage of intron-encoded U18 and snR38 snoRNAs can be reproduced in vitro by incubating together purified Nop1p and Rnt1p. Pull-down experiments showed that the two proteins interact physically. These data indicate that cleavage of U18, snR38 and possibly other intron-encoded snoRNAs is a regulated process, since the stem is cleaved by the Rnt1p endonuclease only when snoRNP assembly has occurred.
|Status: Published||Type: Journal Article | Research Support, Non-U.S. Gov't | Research Support, U.S. Gov't, P.H.S.||PubMed ID: 11726521|
Topics addressed in this paper
Number of different genes curated to this paper: 3
- To go to the Locus page for a gene, click on the gene name.