A MUTANT ALLELE OF THE SUP45 (SAL4) GENE OF SACCHAROMYCES-CEREVISIAE SHOWS TEMPERATURE-DEPENDENT ALLOSUPPRESSOR AND OMNIPOTENT SUPPRESSOR PHENOTYPES

Stansfield, Ian and Tuite, Mick F. (1995) A MUTANT ALLELE OF THE SUP45 (SAL4) GENE OF SACCHAROMYCES-CEREVISIAE SHOWS TEMPERATURE-DEPENDENT ALLOSUPPRESSOR AND OMNIPOTENT SUPPRESSOR PHENOTYPES. Current Genetics, 27 (5). pp. 417-426. ISSN 0172-8083. (The full text of this publication is not available from this repository)

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Abstract

Using a plasmid-based termination-readthrough assay, the sal4-2 conditional-lethal (temperature-sensitive) allele of the SUP45 (SALA) gene was shown to enhance the efficiency of the weak ochre suppressor tRNA SUQ5 some 10-fold at 30 degrees C. Additionally, this allele increased the suppressor efficiency of SRM2-2, a weak tRNA(Gln) ochre suppressor, indicating that the allosuppres sor phenotype is not SUQ5-specific. A sup(+) sal4-2 strain also showed a temperature-dependent omnipotent suppressor phenotype, enhancing readthrough of all three termination codons. Combining the sal4-2 allele with an efficient tRNA nonsense suppressor (SUP4) increased the temperature-sensitivity of that strain, indicating that enhanced nonsense suppressor levels contribute to the conditional-lethality conferred by the sal4-2 allele. However, UGA suppression levels in a sup(+) sal4-2 strain following a shift to the non-permissive temperature reached a maximum significantly below that exhibited by a non-temperature sensitive SUP4 suppressor strain. Enhanced nonsense suppression may not therefore be the primary cause of the conditional-lethality of this allele. These data indicate a role for Sup45p in translation termination, and possibly in an additional, as yet unidentified, cellular process.

Item Type: Article
Uncontrolled keywords: SACCHAROMYCES CEREVISIAE; OMNIPOTENT SUPPRESSION; NONSENSE SUPPRESSION; SUP45
Subjects: Q Science
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: I.T. Ekpo
Date Deposited: 23 May 2009 22:17
Last Modified: 10 Jun 2014 12:55
Resource URI: http://kar.kent.ac.uk/id/eprint/19072 (The current URI for this page, for reference purposes)
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