Quantitation of readthrough of termination codons in yeast using a novel gene fusion assay

Firoozan, Mandy and Grant, Chris M. and Duarte, Julio A.B. and Tuite, Mick F. (1991) Quantitation of readthrough of termination codons in yeast using a novel gene fusion assay. Yeast, 7 (2). pp. 173-183. ISSN 0749-503X. (The full text of this publication is not available from this repository)

The full text of this publication is not available from this repository. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1002/yea.320070211

Abstract

A simple quantitative in vivo assay has been developed for measuring the efficiency of translation of one or other of the three termination codons, UAA, UAG and UGA in Saccharomyces cerevisiae. The assay employs a 3-phosphoglycerate kinase-beta-galactosidase gene fusion, carried on a multicopy plasmid, in which the otherwise retained reading frame is disrupted by one or other of the three termination codons. Termination readthrough is thus quantitated by measuring beta-galactosidase in transformed strains. Using these plasmids to quantitate the endogenous levels of termination readthrough we show that readthrough of all three codons can be detected in a non-suppressor (sup+) strain of S. cerevisiae. The efficiency of this endogenous readthrough is much higher in a [psi+] strain than in a [psi-] strain with the UGA codon being the leakiest in the nucleotide context used. The utility of the assay plasmids for studying genetic modifiers of nonsense suppressors is also shown by their use to demonstrate that the cytoplasmic genetic determinant [psi+] broadens the decoding properties of a serine-inserting UAA suppressor tRNA (SUQ5) to allow it to translate the other two termination codons in the order of efficiency UAA > UAG > UGA.

Item Type: Article
Uncontrolled keywords: translation; saccharomyces-cerevisiae; lacz fusion; termination; nonsense suppression
Subjects: Q Science > QH Natural history > QH301 Biology
Q Science > QR Microbiology
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: O.O. Odanye
Date Deposited: 21 Oct 2009 12:00
Last Modified: 10 Jun 2014 13:06
Resource URI: http://kar.kent.ac.uk/id/eprint/22933 (The current URI for this page, for reference purposes)
  • Depositors only (login required):