MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Villa, T.
Right arrow Articles by Bozzoni, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Villa, T.
Right arrow Articles by Bozzoni, I.

 Previous Article  |  Next Article 

Mol Cell Biol, June 1998, p. 3376-3383, Vol. 18, No. 6
0270-7306/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Processing of the Intron-Encoded U18 Small Nucleolar RNA in the Yeast Saccharomyces cerevisiae Relies on Both Exo- and Endonucleolytic Activities

Tommaso Villa, Francesca Ceradini, Carlo Presutti, and Irene Bozzoni*

Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Genetica e Biologia Molecolare, Università "La Sapienza," Rome, Italy

Received 22 January 1998/Returned for modification 23 February 1998/Accepted 24 March 1998

Many small nucleolar RNAs (snoRNAs) are encoded within introns of protein-encoding genes and are released by processing of their host pre-mRNA. We have investigated the mechanism of processing of the yeast U18 snoRNA, which is found in the intron of the gene coding for translational elongation factor EF-1beta . We have focused our analysis on the relationship between splicing of the EF-1beta pre-mRNA and production of the mature snoRNA. Mutations inhibiting splicing of the EF-1beta pre-mRNA have been shown to produce normal U18 snoRNA levels together with the accumulation of intermediates deriving from the pre-mRNA, thus indicating that the precursor is an efficient processing substrate. Inhibition of 5'right-arrow3' exonucleases obtained by insertion of G cassettes or by the use of a rat1-1 xrn1Delta mutant strain does not impair U18 release. In the Exo- strain, 3' cutoff products, diagnostic of an endonuclease-mediated processing pathway, were detected. Our data indicate that biosynthesis of the yeast U18 snoRNA relies on two different pathways, depending on both exonucleolytic and endonucleolytic activities: a major processing pathway based on conversion of the debranched intron and a minor one acting by endonucleolytic cleavage of the pre-mRNA.

* Corresponding author. Mailing address: Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Genetica e Biologia Molecolare, Università "La Sapienza," P. le A. Moro 5, 00185 Rome, Italy. Phone: 39-6-49912202. Fax: 39-6-49912500. E-mail: bozzoni{at}axcasp.caspur.it.

Mol Cell Biol, June 1998, p. 3376-3383, Vol. 18, No. 6
0270-7306/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 1998 by the American Society for Microbiology. All rights reserved.