Parallel analysis of deletion mutants in Saccharomyces cerevisiae under zinc deficiency

Lithium hexafluorophosphate (LiPF6) is one of the leading electrolytes in lithium-ion batteries, and its usage has increased tremendously in the past few years. Little is known, however, about its potential environmental and biological impacts. In order to improve our understanding of the cytotoxicity of LiPF6 and the specific cellular response mechanisms to it, we performed a genome-wide screen using a yeast (Saccharomyces cerevisiae) deletion mutant collection and identified 75 gene deletion mutants that showed LiPF6 sensitivity. Among these, genes associated with mitochondria showed the most enrichment. We also found that LiPF6 is more toxic to yeast than lithium chloride (LiCl) or sodium hexafluorophosphate (NaPF6). Physiological analysis showed that a high concentration of LiPF6 caused mitochondrial damage, reactive oxygen species (ROS) accumulation, and ATP content changes. Compared with the results of previous genome-wide screening for LiCl-sensitive mutants, we found that oxidative phosphorylation-related mutants were specifically hypersensitive to LiPF6. In these deletion mutants, LiPF6 treatment resulted in higher ROS production and reduced ATP levels, suggesting that oxidative phosphorylation-related genes were important for counteracting LiPF6-induced toxicity. Taken together, our results identified genes specifically involved in LiPF6-modulated toxicity, and demonstrated that oxidative stress and ATP imbalance maybe the driving factors in governing LiPF6-induced toxicity.

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Functional screening for resistance genes against trichothecenes in the library of Saccharomyces cerevisiae deletion mutants

JSM Mycotoxins ◽

10.2520/myco.63.9 ◽

2013 ◽

Vol 63 (1) ◽

pp. 9-15 ◽

Cited By ~ 3

Author(s):

Naoko TAKAHASHI-ANDO ◽

Akira TANAKA ◽

Yohsuke SEKIMOTO ◽

Kohta YAMAUCHI ◽

Akinobu ECHIGO ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Resistance Genes ◽

Deletion Mutants ◽

Functional Screening ◽

Screening For Resistance

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Pleiotropic drug-resistance attenuated genomic library improves elucidation of drug mechanisms

Molecular BioSystems ◽

10.1039/c5mb00406c ◽

2015 ◽

Vol 11 (11) ◽

pp. 3129-3136 ◽

Cited By ~ 12

Author(s):

Namal V. C. Coorey ◽

James H. Matthews ◽

David S. Bellows ◽

Paul H. Atkinson

Keyword(s):

Saccharomyces Cerevisiae ◽

Drug Resistance ◽

Mechanism Of Action ◽

Gene Deletion ◽

Genomic Library ◽

Deletion Mutants ◽

Pleiotropic Drug Resistance ◽

Genome Wide

Identifying Saccharomyces cerevisiae genome-wide gene deletion mutants that confer hypersensitivity to a xenobiotic aids the elucidation of its mechanism of action (MoA).

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Regulation of Copper Metabolism by Nitrogen Utilization in Saccharomyces cerevisiae

Journal of Fungi ◽

10.3390/jof7090756 ◽

2021 ◽

Vol 7 (9) ◽

pp. 756

Author(s):

Suzie Kang ◽

Hyewon Seo ◽

Min-Gyu Lee ◽

Cheol-Won Yun

Keyword(s):

Saccharomyces Cerevisiae ◽

Iron Uptake ◽

Nitrogen Starvation ◽

Copper Metabolism ◽

Nitrogen Utilization ◽

Deletion Mutants ◽

Uptake System ◽

Wild Type ◽

High Affinity ◽

Uptake Activity

To understand the relationship between carbon or nitrogen utilization and iron homeostasis, we performed an iron uptake assay with several deletion mutants with partial defects in carbon or nitrogen metabolism. Among them, some deletion mutants defective in carbon metabolism partially and the MEP2 deletion mutant showed lower iron uptake activity than the wild type. Mep2 is known as a high-affinity ammonia transporter in Saccharomyces cerevisiae. Interestingly, we found that nitrogen starvation resulted in lower iron uptake activity than that of wild-type cells without downregulation of the genes involved in the high-affinity iron uptake system FET3/FTR1. However, the gene expression of FRE1 and CTR1 was downregulated by nitrogen starvation. The protein level of Ctr1 was also decreased by nitrogen starvation, and addition of copper to the nitrogen starvation medium partially restored iron uptake activity. However, the expression of MAC1, which is a copper-responsive transcriptional activator, was not downregulated by nitrogen starvation at the transcriptional level but was highly downregulated at the translational level. Mac1 was downregulated dramatically under nitrogen starvation, and treatment with MG132, which is an inhibitor of proteasome-dependent protein degradation, partially attenuated the downregulation of Mac1. Taken together, these results suggest that nitrogen starvation downregulates the high-affinity iron uptake system by degrading Mac1 in a proteasome-dependent manner and eventually downregulates copper metabolism.

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The GIS2 Gene Is Repressed by a Zinc-Regulated Bicistronic RNA in Saccharomyces cerevisiae

Genes ◽

10.3390/genes9090462 ◽

2018 ◽

Vol 9 (9) ◽

pp. 462 ◽

Cited By ~ 2

Author(s):

Janet Taggart ◽

Yirong Wang ◽

Erin Weisenhorn ◽

Colin W. MacDiarmid ◽

Jason Russell ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Rna Polymerase Ii ◽

Zinc Deficiency ◽

Transcriptional Activation ◽

Open Reading Frames ◽

Zinc Homeostasis ◽

Protein Accumulation ◽

Coding Region ◽

Yeast Saccharomyces Cerevisiae ◽

Short Transcript

Zinc homeostasis is essential for all organisms. The Zap1 transcriptional activator regulates these processes in the yeast Saccharomyces cerevisiae. During zinc deficiency, Zap1 increases expression of zinc transporters and proteins involved in adapting to the stress of zinc deficiency. Transcriptional activation by Zap1 can also repress expression of some genes, e.g., RTC4. In zinc-replete cells, RTC4 mRNA is produced with a short transcript leader that is efficiently translated. During deficiency, Zap1-dependent expression of an RNA with a longer transcript leader represses the RTC4 promoter. This long leader transcript (LLT) is not translated due to the presence of small open reading frames upstream of the RTC4 coding region. In this study, we show that the RTC4 LLT RNA also plays a second function, i.e., repression of the adjacent GIS2 gene. In generating the LLT transcript, RNA polymerase II transcribes RTC4 through the GIS2 promoter. Production of the LLT RNA correlates with the decreased expression of GIS2 mRNA and mutations that prevent synthesis of the LLT RNA or terminate it before the GIS2 promoter renders GIS2 mRNA expression and Gis2 protein accumulation constitutive. Thus, we have discovered an unusual regulatory mechanism that uses a bicistronic RNA to control two genes simultaneously.

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