Saccharomyces cerevisiae
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ABSTRACT:
PROVIDER: PRJNA203300 | ENA |
REPOSITORIES: ENA
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Project description:All eukaryotic cells divide a finite number of times, termed replicative aging, but the reason for this is not clear. Consistent with the decreased total histone protein levels in aged Saccharomyces cerevisiae, which is a cause of aging (1), we find that nucleosome occupancy decreases 50% across the whole genome during replicative aging by spike-in controlled MNase sequencing. Nucleosomes become fuzzier or move to sequences predicted to better accommodate histone octamers. All yeast genes are induced during aging. Genes that are repressed in young cells are most induced, accompanied by nucleosome loss from their promoters that have unique chromatin organization. Contrary to the loss of mitochondrial function during aging, mitochondrial DNA content increases and unprecedented levels of large-scale chromosomal alterations and increased retrotransposition are observed. Mnase-Seq experiments were carried out for young yeast, old yeast, and old yeast with histone over expression, 3 replicates were done for each category. RNA-Seq were carried out for the same categories of yeast cells but with 2 replicates for each. Genome-Seq were done for the young and old yeast with 2 replicates for each.
2014-02-26 | E-GEOD-47023 | biostudies-arrayexpress
Project description:All eukaryotic cells divide a finite number of times, termed replicative aging, but the reason for this is not clear. Consistent with the decreased total histone protein levels in aged Saccharomyces cerevisiae, which is a cause of aging (1), we find that nucleosome occupancy decreases 50% across the whole genome during replicative aging by spike-in controlled MNase sequencing. Nucleosomes become fuzzier or move to sequences predicted to better accommodate histone octamers. All yeast genes are induced during aging. Genes that are repressed in young cells are most induced, accompanied by nucleosome loss from their promoters that have unique chromatin organization. Contrary to the loss of mitochondrial function during aging, mitochondrial DNA content increases and unprecedented levels of large-scale chromosomal alterations and increased retrotransposition are observed.
2014-02-26 | GSE47023 | GEO
Project description:Yeast replicative aging is a process resembling replicative aging in mammalian cells. During aging, wild type haploid yeast cells enlarge, become sterile, and undergo nucleolar enlargement and fragmentation; we sought gene expression changes during the time of these phenotypic changes. Gene expression studied via microarrays and qPCR has shown reproducible, statistically significant changes in mRNA of genes at 12 and 18-20 generations. Our findings support previously described changes towards aerobic metabolism, decreased ribosome gene expression, and a partial Environmental Stress Response. Our novel findings include a pseudo-stationary phase, down-regulation of methylation-related metabolism, increased Nucleotide Excision Repair related mRNA, and a strong up-regulation of many of the regulatory subunits of protein phosphatase I (Glc7). These findings are correlated with aging changes in higher organisms as well as with the known involvement of protein phosphorylation states during yeast aging. J Gerontol, Jan, 2008, vol 63A, no. 1. Keywords: aging time course
2008-02-01 | GSE10018 | GEO
Project description:Sir2 is a highly conserved NAD+-dependent histone deacetylase that functions in heterochromatin formation and promotes replicative lifespan (RLS) in the budding yeast, Saccharomyces cerevisiae. Within the yeast rDNA locus, Sir2 is required for efficient cohesin recruitment and maintaining stability of the tandem array. In addition to the previously reported depletion of Sir2 in replicatively aged cells, we discovered that subunits of the Sir2 containing complexes, SIR and RENT, were depleted. Several other rDNA structural protein complexes also exhibited age-related depletion, most notably the cohesin complex. We hypothesized that mitotic chromosome instability (CIN) due to cohesin depletion could be a driver of replicative aging. ChIP assays of the residual cohesin (Mcd1-13xMyc) in moderately aged cells showed strong depletion from the rDNA and initial redistribution to the point centromeres, which was then lost in older cells. Despite the shift in cohesin distribution, sister chromatid cohesion was partially attenuated in aged cells and the frequency of chromosome loss was increased. This age-induced CIN was exacerbated in strains lacking Sir2 and its paralog, Hst1, but suppressed in strains that stabilize the rDNA array due to deletion of FOB1 or through caloric restriction (CR). Furthermore, ectopic expression of MCD1 from a doxycycline-inducible promoter was sufficient to suppress rDNA instability in aged cells and to extend RLS. Taken together we conclude that age-induced depletion of cohesin and multiple other nucleolar chromatin factors destabilize the rDNA locus, which then results in general CIN and aneuploidy that shortens RLS.
2019-03-12 | GSE117037 | GEO
Project description:Aneuploidy and aging are correlated; however, a causal link between these two phenomena has remained elusive. Here we show that yeast disomic for a single native yeast chromosome generally have a decreased replicative lifespan. In addition, the extent of this lifespan deficit correlates with the size of the extra chromosome. We identified a mutation in BUL1 that rescues both the lifespan deficit and a protein trafficking defect in yeast disomic for chromosome 5. Bul1 is an E4 ubiquitin ligase adaptor involved in a protein quality-control pathway that targets membrane proteins for endocytosis and destruction in the lysosomal vacuole thereby maintaining protein homeostasis. Concurrent suppression of the aging and trafficking phenotypes suggests that disrupted membrane protein homeostasis in aneuploid yeast may contribute to their accelerated aging. The data reported here demonstrate that aneuploidy can impair protein homeostasis, shorten lifespan, and may contribute to age-associated phenotypes. These are all CGH arrays comparing DNA content between the indicated strain of interest and a wt control.
2015-12-04 | E-GEOD-75623 | biostudies-arrayexpress
Project description:Aneuploidy and aging are correlated; however, a causal link between these two phenomena has remained elusive. Here we show that yeast disomic for a single native yeast chromosome generally have a decreased replicative lifespan. In addition, the extent of this lifespan deficit correlates with the size of the extra chromosome. We identified a mutation in BUL1 that rescues both the lifespan deficit and a protein trafficking defect in yeast disomic for chromosome 5. Bul1 is an E4 ubiquitin ligase adaptor involved in a protein quality-control pathway that targets membrane proteins for endocytosis and destruction in the lysosomal vacuole thereby maintaining protein homeostasis. Concurrent suppression of the aging and trafficking phenotypes suggests that disrupted membrane protein homeostasis in aneuploid yeast may contribute to their accelerated aging. The data reported here demonstrate that aneuploidy can impair protein homeostasis, shorten lifespan, and may contribute to age-associated phenotypes.
2015-12-04 | GSE75623 | GEO
Project description:Protein synthesis is strictly regulated during replicative aging in yeast, but global translational regulation during replicative aging is poorly characterized. To conduct ribosomal profiling during replicative aging, we collected a large number of dividing aged cells using a miniature chemostat aging device. Translational efficiency, defined as the number of ribosome footprints normalized to transcript abundance, was compared between young and aged cells for each gene. We identified more than 700 genes with changes greater than twofold during replicative aging. Increased translational efficiency was observed in genes involved in DNA repair and chromosome organization. Decreased translational efficiency was observed in genes encoding ribosome components, transposon Ty1 and Ty2 genes, transcription factor HAC1 genes associated with the unfolded protein response, genes involved in cell wall synthesis and assembly, and ammonium permease genes. Our results provide a global view of translational regulation during replicative aging, in which the pathways involved in various cell functions are translationally regulated and cause diverse phenotypic changes.
2022-09-25 | GSE203147 | GEO
Project description:Epigenetic mechanisms including histone post-translational modifications control longevity in diverse organisms. Relatedly, loss of proper transcriptional regulation on a global scale is an emerging aspect of shortened lifespan, but the specific mechanisms linking these observations remain to be uncovered. Here, we describe a lifespan screen in S. cerevisiae, designed to identify altered amino acid residues of histones that alter yeast replicative aging. Our results reveal that lack of sustained H3K36 methylation is commensurate with increased cryptic transcription in a set of genes in old cells and shorter lifespan. Deletion of the K36me2/3 demethylase Rph1 increases H3K36me3 within these genes and suppresses cryptic transcript initiation to extend lifespan. We show that this aging phenomenon is conserved, as cryptic transcription also increases in old worms. We propose that epigenetic misregulation in aging cells leads to an increase in transcriptional noise that is detrimental to lifespan, and, importantly, this acceleration in aging can be reversed by restoring transcriptional fidelity.
2015-07-17 | GSE65765 | GEO
Project description:Epigenetic mechanisms including histone post-translational modifications control longevity in diverse organisms. Relatedly, loss of proper transcriptional regulation on a global scale is an emerging aspect of shortened lifespan, but the specific mechanisms linking these observations remain to be uncovered. Here, we describe a lifespan screen in S. cerevisiae, designed to identify altered amino acid residues of histones that alter yeast replicative aging. Our results reveal that lack of sustained H3K36 methylation is commensurate with increased cryptic transcription in a set of genes in old cells and shorter lifespan. Deletion of the K36me2/3 demethylase Rph1 increases H3K36me3 within these genes and suppresses cryptic transcript initiation to extend lifespan. We show that this aging phenomenon is conserved, as cryptic transcription also increases in old worms. We propose that epigenetic misregulation in aging cells leads to an increase in transcriptional noise that is detrimental to lifespan, and, importantly, this acceleration in aging can be reversed by restoring transcriptional fidelity.
2015-07-17 | GSE65764 | GEO
Project description:Epigenetic mechanisms including histone post-translational modifications control longevity in diverse organisms. Relatedly, loss of proper transcriptional regulation on a global scale is an emerging aspect of shortened lifespan, but the specific mechanisms linking these observations remain to be uncovered. Here, we describe a lifespan screen in S. cerevisiae, designed to identify altered amino acid residues of histones that alter yeast replicative aging. Our results reveal that lack of sustained H3K36 methylation is commensurate with increased cryptic transcription in a set of genes in old cells and shorter lifespan. Deletion of the K36me2/3 demethylase Rph1 increases H3K36me3 within these genes and suppresses cryptic transcript initiation to extend lifespan. We show that this aging phenomenon is conserved, as cryptic transcription also increases in old worms. We propose that epigenetic misregulation in aging cells leads to an increase in transcriptional noise that is detrimental to lifespan, and, importantly, this acceleration in aging can be reversed by restoring transcriptional fidelity.
2015-07-17 | GSE65766 | GEO