Eukaryotic Cell doi:10.1128/EC.00355-06
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
Identification of cellular processes and pathways that protect yeast cells against the plasma membrane-perturbing compound chitosan
Anna Zakrzewska*,
Andre Boorsma,
Daniela Delneri,
Stanley Brul,
Stephen G. Oliver,
and
Frans M. Klis
Molecular Microbial Physiology, Molecular Biology and Microbial Food Safety, Swammerdam Institute of Life Sciences, Nieuwe Achtergracht 166, 1018WV Amsterdam, The Netherlands; Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, United Kingdom
* To whom correspondence should be addressed. Email:
A.M.Zakrzewska{at}uva.nl.
 |
Abstract |
|---|
Global fitness analysis makes use of a genomic library of tagged deletion strains. We used this approach to study the effect of chitosan, which causes plasma membrane stress. The data were analyzed using T-profiler, which was based on determining the sensitivity to chitosan of groups of deletion strains, as defined by Gene Ontology (GO) and by genomic synthetic lethality screens, in combination with t-statistics. The chitosan-hypersensitive groups included a group of deletion strains characterized by a defective HOG signaling pathway, indicating that the HOG pathway is required for counteracting chitosan-induced stress. Consistent with this, activation of this pathway in wild-type cells by hypertonic conditions offered partial protection against chitosan, whereas hypotonic conditions sensitized the cells to chitosan. Other chitosan-hypersensitive groups were defective in RNA synthesis and processing, actin cytoskeleton organization, protein N-glycosylation, ergosterol synthesis, endocytosis, or in cell wall formation, predicting that these cellular functions buffer the cell against the deleterious effect of chitosan. These predictions were supported by showing that tunicamycin, miconazole, and staurosporine (which target protein N-glycosylation, ergosterol synthesis, and the cell wall integrity pathway, respectively) sensitized yeast cells to chitosan. Intriguingly, the GO-defined group of deletion strains cytosolic large ribosomal subunit was more resistant to chitosan. We propose that global fitness analysis of yeast in combination with T-profiler is a powerful tool to identify specific cellular processes and pathways that are required for survival under stress conditions.
Previous Article | Next Article 
