title: A chemical potentiator of copper-accumulation used to investigate the iron-regulons of Saccharomyces cerevisiae.
abstract: The extreme resistance of Saccharomyces cerevisiae to copper is overcome by 2-(6-benzyl-2-pyridyl)quinazoline (BPQ), providing a chemical-biology tool which has been exploited in two lines of discovery. First, BPQ is shown to form a red (BPQ)2 Cu(I) complex and promote Ctr1-independent copper-accumulation in whole cells and in mitochondria isolated from treated cells. Multiple phenotypes, including loss of aconitase activity, are consistent with copper-BPQ mediated damage to mitochondrial iron-sulphur clusters. Thus, a biochemical basis of copper-toxicity in S. cerevisiae is analogous to other organisms. Second, iron regulons controlled by Aft1/2, Cth2 and Yap5 that respond to mitochondrial iron-sulphur cluster status are modulated by copper-BPQ causing iron hyper-accumulation via upregulated iron-import. Comparison of copper-BPQ treated, untreated and copper-only treated wild-type and fra2Δ by RNA-seq has uncovered a new candidate Aft1 target-gene (LSO1) and paralogous non-target (LSO2), plus nine putative Cth2 target-transcripts. Two lines of evidence confirm that Fra2 dominates basal repression of the Aft1/2 regulons in iron-replete cultures. Fra2-independent control of these regulons is also observed but CTH2 itself appears to be atypically Fra2-dependent. However, control of Cth2-target transcripts which is independent of CTH2 transcript abundance or of Fra2, is also quantified. Use of copper-BPQ supports a substantial contribution of metabolite repression to iron-regulation.
authors.affiliation: Department of Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham, DH1 3LE, UK.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Foster
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Dainty
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Patterson
authors.forename: Ehmke
authors.initials: E
authors.lastname: Pohl
authors.forename: Hannah
authors.initials: H
authors.lastname: Blackburn
authors.forename: Clare
authors.initials: C
authors.lastname: Wilson
authors.forename: Corinna R
authors.initials: CR
authors.lastname: Hess
authors.forename: Julian C
authors.initials: JC
authors.lastname: Rutherford
authors.forename: Laura
authors.initials: L
authors.lastname: Quaranta
authors.forename: Andy
authors.initials: A
authors.lastname: Corran
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Robinson
mesh_terms: D003300:Copper / Q000378:metabolism* / Q000633:toxicity; D003461:Crystallography; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D006706:Homeostasis; D007501:Iron / Q000378:metabolism*; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism; D005810:Multigene Family; D011799:Quinazolines / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018085:Regulon; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013455:Sulfur / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: C000601535:2-(6-benzyl-2-pyridyl)quinazoline; D011799:Quinazolines; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D013455:Sulfur; D003300:Copper; D007501:Iron