Project description:This study addresses the effect of mutations related to sense and antisense transcription of Saccharomyces cerevisiae phosphate genes using strand-specific RNAseq. Replacement of the transcriptional terminator of PHO84 by that of CYC1 resulted, unexpectedly, in an increased antisense transcription and a strongly reduced sense transcription of PHO84. Also RNA levels of SPL2 were strongly reduced. Deletion of the PHO84 coding region did not markedly affect the expression of SPL2, suggesting that antisense transcription of PHO84 and not the Pho84 transporter affects the expression of SPL2. Deletion of the two putative binding sites for the transcriptional regulator Ume6 in the SPL2 promoter resulted in a slightly increased level of SPL2 RNA, whereas deletion of the UME6 gene resulted in a decreased level of SPL2 and PHO84 RNA. These results suggests that Ume6 is involved in the regulation of SPL2 by a mechanism different from a simple binding to the putative Ume6 binding sites.
Project description:Abf1 and Reb1, two general regulatory factors playing roles at promoters and other genome functional sites in budding yeast, were mapped genome-wide by ChIP-sequencing using strains expressing TAP-tagged versions of the proteins. As expected on the basis of previous in silico analysis of promoter regions, we found that these factors are enriched at the promoters of ribosome biogenesis (Ribi) genes, a large regulon of more than 200 genes required for ribosome biosynthesis and assembly, and known to be coordinately regulated in response to nutrient availability and cellular growth rate.
Project description:RNA-seq was used to assess mRNA transcript abundance in wild type and fra2Δ S. cerevisiae (BY4741) cells treated with 2-(6-benzyl-2-pyridyl)quinazoline (BPQ) and CuSO4. BPQ potentiates copper toxicity and in yeast, in common with other organisms, a major cause of copper toxicity is damage of iron-sulphur clusters. Iron sensing within yeast relies on mitochondrial iron-sulphur cluster biosynthesis and therefore treatment with BPQ and copper can be used to mimic iron deficiency. Fra2 is known to be a key component of the iron sensing mechanism; however, this mechanism can operate, to an extent, independently of Fra2. BPQ (+CuSO4) treatment was used with the aim of probing the regulation of the iron regulon of S. cerevisiae and the role of Fra2 in the suppression of the low iron response. This study has uncovered nine new Cth2 target-transcripts, plus a new Aft1 target-gene and paralogous non-target. Fra2 dominates basal repression of the iron regulon in iron-replete cultures, however, Fra2-independent control of the iron regulon is also observed with CTH2 appearing to be atypically Fra2-dependent. Transcripts from untreated and CuSO4 treated cells were included as controls.
Project description:To determine the complement of Ume6-dependent genes expressed during mitosis and/or meiosis in budding yeast we compared wild-type and<br>ume6 deletion strains using Yeast 2.0 high density oligonucleotide microarrays (GeneChips). Samples were analysed from cells growing in rich medium with fermentable (glucose) and non-fermentable (acetate) carbon sources and from cells undergoing meiosis and spore formation in sporulation medium. Expression data were combined with data from a genome-wide Ume6 DNA binding assay and Ume6-target site prediction to identify the most likely direct target genes of Ume6.
Project description:Arginine auxotrophy by deletion of the mitochondrial selectable marker ARG8 in Saccharomyces cerevisiae can be reverted by loss-of-function mutations in UME6
Project description:Nucleosome positions were determined in wild type cells, cells lacking Isw2 or Ume6, and cells containing a hybrid Chd1-Ume6 chimeric remodeler
Project description:We determined that extrachromosomal 2μ plasmid was present in 67 of the Saccharomyces cerevisiae 100-genome strains; in addition to variation in the size and copy number of 2μ, we identified three distinct classes of 2μ. We identified 2μ presence/absence and class associations with populations, clinical origin and nuclear genotypes. We also screened genome sequences of S. paradoxus, S. kudriavzevii, S. uvarum, S. eubayanus, S. mikatae, S. arboricolus and S. bayanus strains for both integrated and extrachromosomal 2μ. Similar to S. cerevisiae, we found no integrated 2μ sequences in any S. paradoxus strains. However, we identified part of 2μ integrated into the genomes of some S. uvarum, S. kudriavzevii, S. mikatae and S. bayanus strains, which were distinct from each other and from all extrachromosomal 2μ. We identified extrachromosomal 2μ in one S. paradoxus, one S. eubayanus, two S. bayanus and 13 S. uvarum strains. The extrachromosomal 2μ in S. paradoxus, S. eubayanus and S. cerevisiae were distinct from each other. In contrast, the extrachromosomal 2μ in S. bayanus and S. uvarum strains were identical with each other and with one of the three classes of S. cerevisiae 2μ, consistent with interspecific transfer.