A Genome-Wide Screen in Saccharomyces cerevisiae Reveals a Critical Role for Oxidative Phosphorylation in Cellular Tolerance to Lithium Hexafluorophosphate

Abstract

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.

Retromer Complex and PI3K Complex II-Related Genes Mediate the Yeast (Saccharomyces cerevisiae) Sodium Metabisulfite Resistance Response

“…The information of all deletion mutants tested in this screen along with their fitness scores can be found in Table S4 . In order to clarify the functions of genes involved in Na 2 S 2 O 5 tolerance, we then performed a GO enrichment analysis of genes deleted in Na 2 S 2 O 5 sensitive mutants using GO Term Finder [ 24 ]. We found that gene deletions in strains with increased sensitivity are enriched in various groups.…”

“…In terms of molecular function, only “structural constituent of ribosome” was enriched ( Figure 1 B). We also conducted a KEGG analysis of the sensitive strains [ 24 ], and five enriched pathways were identified including “ribosome”, “endocytosis”, “RNA degradation”, “various types of N -glycan biosynthesis”, and “mitophagy” ( Figure 1 C). In summary, from the GO and KEGG analysis, we can see that transport-, ribosome-, RNA metabolism-, and autophagy/mitophagy-related genes were the main genes that responded to Na 2 S 2 O 5 .…”

“…In summary, from the GO and KEGG analysis, we can see that transport-, ribosome-, RNA metabolism-, and autophagy/mitophagy-related genes were the main genes that responded to Na 2 S 2 O 5 . In addition, functional classification and physical interaction analysis of these 162 genes were performed as previously described [ 24 ]. This analysis demonstrated that the encoded products of over 50% of these genes have physical interactions with each other ( Figure 1 D).…”

“…Pre-cultures were diluted to an OD 600 of 0.5 in yeast peptone dextrose (YPD) supplemented with 0 mM, 5 mM, 10 mM, 15 mM, and 20 mM of Na 2 S 2 O 5 (dissolved in ddH 2 O). Cell growth was monitored by a spectrophotometer (Ultrospec 2100 Pro, Biochrom, St. Albans, UK) at different time points, as described previously [ 24 ].…”

“…The screening was carried out as described previously [ 24 ]. Briefly, the SGA-v2 strains were arrayed in 384-format.…”