title: Functional genomics of drug-induced ion homeostasis identifies a novel regulatory crosstalk of iron and zinc regulons in yeast.
abstract: Pyrrolidine dithiocarbamate (PDTC), a known inhibitor of NFκB activation, has antioxidative as well as antiviral activities. PDTC is effective against several virus families, indicating that its antiviral mechanism targets host rather than viral functions. To investigate its mode of action, we used baker's yeast as a simple eukaryotic model system and two types of genome-wide analysis. First, expression profiling using whole-genome DNA microarrays identifies more than 200 genes differentially regulated upon PDTC exposure. Interestingly, the Aft1-dependent iron regulon is a main target of PDTC, indicating a lack of iron availability. Moreover, the PDTC-caused zinc influx triggers a strong regulatory effect on zinc transporters due to the cytoplasmic zinc excess. Second, phenotypic screening the EUROSCARF collection for PDTC hypersensitivity identifies numerous mutants implicated in vacuolar maintenance, acidification as well as in transport, mitochondrial organization, and translation. Notably, the screening data indicate significant overlaps of PDTC-sensitive genes and those mediating zinc tolerance. Hence, we show that PDTC induces cytoplasmic zinc excess, eliciting vacuolar detoxification, which in turn, disturbs iron homeostasis and activates the iron-dependent regulator Aft1. Our work reveals a complex crosstalk in yeast ion homeostasis and the underlying regulatory networks.
authors.affiliation: Medical University Vienna, Max F. Perutz Laboratories, Campus Vienna Biocenter, A-1030 Vienna, Austria.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Landstetter
authors.forename: Walter
authors.initials: W
authors.lastname: Glaser
authors.forename: Christa
authors.initials: C
authors.lastname: Gregori
authors.forename: Joachim
authors.initials: J
authors.lastname: Seipelt
authors.forename: Karl
authors.initials: K
authors.lastname: Kuchler
mesh_terms: D015152:Blotting, Northern; D002176:Candida albicans / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects / Q000235:genetics; D023281:Genomics; D006706:Homeostasis / Q000187:drug effects* / Q000235:genetics; D015151:Immunoblotting; D007501:Iron / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011759:Pyrrolidines / Q000494:pharmacology*; D018085:Regulon / Q000187:drug effects* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D013859:Thiocarbamates / Q000494:pharmacology*; D015032:Zinc / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D011759:Pyrrolidines; D013859:Thiocarbamates; C020972:pyrrolidine dithiocarbamic acid; D007501:Iron; D015032:Zinc