The Candida albicans Sup35p protein (CaSup35p): function, prion-like behaviour and an associated polyglutamine length polymorphism

Resende, Catarina and Parham, Steven N. and Tinsley, Caroline and Ferreira, Paulo C. and Duarte, Julio A.B. and Tuite, Mick F. (2002) The Candida albicans Sup35p protein (CaSup35p): function, prion-like behaviour and an associated polyglutamine length polymorphism. Microbiology, 148 (Pt 4). pp. 1049-1060. ISSN 0002-4564. (The full text of this publication is not available from this repository)

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Abstract

The Sup35p protein of Saccharomyces cerevisiae is an essential translation factor whose prion-like properties give rise to the non-Mendelian genetic element [PSI(+)]. In this study the SUP35 gene from the related yeast species Candida albicans has been characterized. The CaSUP35 gene encodes a protein (CaSup35p) of 729 aa which shows 65% amino acid identity to the S. cerevisiae Sup35p protein (ScSup35p), with the C-terminal region showing greater identity (79%) than the N-terminal region. The full-length CaSup35p can functionally replace ScSup35p in S. cerevisiae although complementation is only complete when CaSup35p is overexpressed. Complementation only requires expression of the CaSup35p C domain. In S. cerevisiae the full-length CaSup35p is unable to establish a prion-like aggregated state even in the presence of endogenous ScSup35p prion 'seeds', thus confirming the existence of a species barrier in fungal prion propagation. Subcellular localization studies in C. albicans show that although CaSup35p is normally ribosome-associated, when not ribosome-associated, it does not form pelletable high-molecular-mass aggregates characteristic of the ScSup35p in [PSI(+)] strains. Unlike the ScSup35p, the CaSup35p N domain contains a number of polyglutamine repeats although it does contain seven copies of the peptide GGYQQ that is repeated in the ScSup35p N domain. Analysis of the CaSUP35 gene from 14 different strains of C. albicans identified four naturally occurring polymorphisms associated with changes in the length of the largest of the polyglutamine repeats. These findings have important implications for the evolution of fungal prion genes.

Item Type: Article
Additional information: 1350-0872 (Print) Journal Article Research Support, Non-U.S. Gov't
Uncontrolled keywords: Amino Acid Sequence Bacterial Proteins/chemistry/*genetics Base Sequence Candida albicans/*genetics/growth & development DNA Primers Fungal Proteins/chemistry/*genetics Gene Deletion Genetic Complementation Test Genotype Molecular Sequence Data Peptides/*genetics Plasmids *Polymorphism, Genetic Polymorphism, Single Nucleotide Prions/chemistry/*genetics Ribosomes/metabolism Saccharomyces cerevisiae/genetics *Saccharomyces cerevisiae Proteins Sequence Alignment Sequence Homology, Amino Acid
Subjects: Q Science > QR Microbiology
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences > Protein Science Group
Depositing User: Mick Tuite
Date Deposited: 09 Sep 2008 17:03
Last Modified: 04 Jul 2014 11:32
Resource URI: http://kar.kent.ac.uk/id/eprint/5470 (The current URI for this page, for reference purposes)
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