Genome-wide analysis of caesium and strontium accumulation in Saccharomyces cerevisiae

• Published in: Yeast (Chichester, England) England), 2010-10, Vol.27 (10), p.817-835
• Main Authors: Heuck, Sabine, Gerstmann, Udo C, Michalke, Bernhard, Kanter, Ulrike
• Format: Article
• Language: English
• Subjects: Biological Transport; caesium; Calcium - metabolism; Cesium - metabolism; comparison of essential and non‐essential ions; Computational Biology; Culture Media; Gene Expression Regulation, Fungal; Genome, Fungal - genetics; Homeostasis; ion homeostasis; Mutation; Potassium - metabolism; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; strontium; Strontium - metabolism; Vacuoles - metabolism
• ISSN: 0749-503X; 1097-0061; 1097-0061
• DOI: 10.1002/yea.1780

¹³⁷Cs and ⁹⁰Sr contribute to significant and long-lasting contamination of the environment with radionuclides. Due to their relatively high biological availability, they are transferred rapidly into biotic systems and may enter the food chain. In this study, we analysed 4862 haploid yeast knockout strains of Saccharomyces cerevisiae to identify genes involved in caesium (Cs⁺) and/or strontium (Sr²⁺) accumulation. According to this analysis, 212 mutant strains were associated with reproducible altered Cs⁺ and/or Sr²⁺ accumulation. These mutants were deficient for a wide range of cellular processes. Among those, the vacuolar function and biogenesis turned out to be crucial for both Cs⁺ and Sr²⁺ accumulation. Disruption of the vacuole diminished Cs⁺ accumulation, whereas Sr²⁺ enrichment was enhanced. Further analysis with a subset of the identified candidates were undertaken comparing the accumulation of Cs⁺ and Sr²⁺ with their essential counterparts potassium (K⁺) and calcium (Ca²⁺). Sr²⁺ and Ca²⁺ accumulation was highly correlated in yeast excluding the possibility of a differential regulation or uptake mechanisms. In direct contrast, the respective results suggest that Cs⁺ uptake is at least partially dependent on mechanisms distinct from K⁺ uptake. Single candidates (e.g. KHA1) are presented which might be specifically responsible for Cs⁺ homeostasis. Copyright © 2010 John Wiley & Sons, Ltd.