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 Salas-Marco, J.
Right arrow Articles by Bedwell, D. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Salas-Marco, J.
Right arrow Articles by Bedwell, D. M.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, September 2004, p. 7769-7778, Vol. 24, No. 17
0270-7306/04/$08.00+0     DOI: 10.1128/MCB.24.17.7769-7778.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

GTP Hydrolysis by eRF3 Facilitates Stop Codon Decoding during Eukaryotic Translation Termination

Joe Salas-Marco and David M. Bedwell*

Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama

Received 10 February 2004/ Returned for modification 16 March 2004/ Accepted 8 June 2004

Translation termination in eukaryotes is mediated by two release factors, eRF1 and eRF3. eRF1 recognizes each of the three stop codons (UAG, UAA, and UGA) and facilitates release of the nascent polypeptide chain. eRF3 is a GTPase that stimulates the translation termination process by a poorly characterized mechanism. In this study, we examined the functional importance of GTP hydrolysis by eRF3 in Saccharomyces cerevisiae. We found that mutations that reduced the rate of GTP hydrolysis also reduced the efficiency of translation termination at some termination signals but not others. As much as a 17-fold decrease in the termination efficiency was observed at some tetranucleotide termination signals (characterized by the stop codon and the first following nucleotide), while no effect was observed at other termination signals. To determine whether this stop signal-dependent decrease in the efficiency of translation termination was due to a defect in either eRF1 or eRF3 recycling, we reduced the level of eRF1 or eRF3 in cells by expressing them individually from the CUP1 promoter. We found that the limitation of either factor resulted in a general decrease in the efficiency of translation termination rather than a decrease at a subset of termination signals as observed with the eRF3 GTPase mutants. We also found that overproduction of eRF1 was unable to increase the efficiency of translation termination at any termination signals. Together, these results suggest that the GTPase activity of eRF3 is required to couple the recognition of translation termination signals by eRF1 to efficient polypeptide chain release.

* Corresponding author. Mailing address: Department of Microbiology, BBRB 432/Box 8, 1530 Third Ave. South, University of Alabama at Birmingham, Birmingham, AL 35294-2170. Phone: (205) 934-6593. Fax: (205) 975-5482. E-mail: dbedwell{at}uab.edu.

Molecular and Cellular Biology, September 2004, p. 7769-7778, Vol. 24, No. 17
0022-538X/04/$08.00+0     DOI: 10.1128/MCB.24.17.7769-7778.2004
Copyright © 2004, 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 © 2004 by the American Society for Microbiology. All rights reserved.