A system to identify inhibitors of mTOR signaling using high-resolution growth analysis in Saccharomyces cerevisiae

Lee, Mitchell; Carr, Daniel; Kiflezghi, Michael G.; Zhao, Yan Ting; Kim, Deborah B.; Thon, Socheata; Moore, Margarete D; Li, Mary Ann K; Kaeberlein, Matt

doi:10.1007/s11357-017-9988-4

Cited by 23 publications

(16 citation statements)

References 81 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Replicative lifespan was calculated as the number of times each mother cell divided before it underwent senescence. Yeast growth rates were analyzed using the Bioscreen C automated microbiology growth curve analysis system (Growth Curves USA) as described (45,46).…”

Section: Methodsmentioning

confidence: 99%

Genetic screen identifies adaptive aneuploidy as a key mediator of ER stress resistance in yeast

Beaupère

Dinatto

Wasko

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

The yeast genome becomes unstable during stress, which often results in adaptive aneuploidy, allowing rapid activation of protective mechanisms that restore cellular homeostasis. In this study, we performed a genetic screen in to identify genome adaptations that confer resistance to tunicamycin-induced endoplasmic reticulum (ER) stress. Whole-genome sequencing of tunicamycin-resistant mutants revealed that ER stress resistance correlated significantly with gains of chromosomes II and XIII. We found that chromosome duplications allow adaptation of yeast cells to ER stress independently of the unfolded protein response, and that the gain of an extra copy of chromosome II alone is sufficient to induce protection from tunicamycin. Moreover, the protective effect of disomic chromosomes can be recapitulated by overexpression of several genes located on chromosome II. Among these genes, overexpression of UDP--acetylglucosamine-1-P transferase (), a subunit of the 20S proteasome (), and induced tunicamycin resistance in wild-type cells, whereas deletion of all three genes completely reversed the tunicamycin-resistance phenotype. Together, our data demonstrate that aneuploidy plays a critical role in adaptation to ER stress by increasing the copy number of ER stress protective genes. While aneuploidy itself leads to proteotoxic stress, the gene-specific effects of chromosome II aneuploidy counteract the negative effect resulting in improved protein folding.

show abstract

Section: Methodsmentioning

confidence: 99%

Genetic screen identifies adaptive aneuploidy as a key mediator of ER stress resistance in yeast

Beaupère

Dinatto

Wasko

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Disclaimer The data were presented at the 14th International Symposium on Neurobiology and Neuroendocrinology of Aging (July 15-20, 2018, Bregenz, Austria). This paper is part of a special collection of papers published in GeroScience on the oxidation-inflammation theory of aging (Tucsek et al 2017;Konopka et al 2017;Aiello et al 2017;Blodgett et al 2017;Deepa et al 2017;Jackson et al 2017;Lee et al 2017;Meschiari et al 2017;Nikolich-Zugich and van Lier 2017;Perrott et al 2017;Rais et al 2017;Shobin et al 2017;Souquette et al 2017).…”

Section: Compliance With Ethical Standardsmentioning

confidence: 99%

Nrf2 deficiency in aged mice exacerbates cellular senescence promoting cerebrovascular inflammation

et al. 2018

View full text Add to dashboard Cite

Aging-induced pro-inflammatory phenotypic alterations of the cerebral vasculature critically contribute to the pathogenesis of vascular cognitive impairment. Cellular senescence is a fundamental aging process that promotes inflammation; however, its role in cerebrovascular aging remains unexplored. The present study was undertaken to test the hypothesis that advanced aging promotes cellular senescence in the cerebral vasculature. We found that in cerebral arteries of 24-month-old mice, expression of molecular markers of senescence (p16 INK4a , p21) is upregulated as compared to that in young controls. Induction of senescence programs in cerebral arteries is associated by an upregulation of a wide range of inflammatory cytokines and chemokines, which are known to contribute to the senescence-associated secretory phenotype (SASP) in vascular cells. Age-related cerebrovascular senescence and inflammation are associated with neuroinflammation, as shown by the molecular footprint of microglia activation in the hippocampus. Genetic depletion of the pro-survival/anti-aging transcriptional regulator Nrf2 exacerbated age-related induction of senescence markers and inflammatory SASP factors and resulted in a heightened inflammatory status of the hippocampus. In conclusion, our studies provide evidence that aging and Nrf2 dysfunction promote cellular senescence in cerebral vessels, which may potentially cause or exacerbate age-related pathology.

show abstract

“…In addition to survival, we sought to understand how MA impacted overall population health. One way to assess health in a microbial culture is to quantify peak doubling time (minutes per cell division) in an outgrowing population (65). We measured growth of the MA lines with a Bioscreen C MBR reader/shaker/ incubator and calculated doubling time using YODA (63).…”

Section: Effect Of Random Mutation Burden On Rls and Doubling Time Inmentioning

confidence: 99%

Defining the impact of mutation accumulation on replicative lifespan in yeast using cancer-associated mutator phenotypes

Lee

Dowsett

Carr

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Mutations accumulate within somatic cells and have been proposed to contribute to aging. It is unclear what level of mutation burden may be required to consistently reduce cellular lifespan. Human cancers driven by a mutator phenotype represent an intriguing model to test this hypothesis, since they carry the highest mutation burdens of any human cell. However, it remains technically challenging to measure the replicative lifespan of individual mammalian cells. Here, we modeled the consequences of cancer-related mutator phenotypes on lifespan using yeast defective for mismatch repair (MMR) and/or leading strand (Polε) or lagging strand (Polδ) DNA polymerase proofreading. Only haploid mutator cells with significant lifetime mutation accumulation (MA) exhibited shorter lifespans. Diploid strains, derived by mating haploids of various genotypes, carried variable numbers of fixed mutations and a range of mutator phenotypes. Some diploid strains with fewer than two mutations per megabase displayed a 25% decrease in lifespan, suggesting that moderate numbers of random heterozygous mutations can increase mortality rate. As mutation rates and burdens climbed, lifespan steadily eroded. Strong diploid mutator phenotypes produced a form of genetic anticipation with regard to aging, where the longer a lineage persisted, the shorter lived cells became. Using MA lines, we established a relationship between mutation burden and lifespan, as well as population doubling time. Our observations define a threshold of random mutation burden that consistently decreases cellular longevity in diploid yeast cells. Many human cancers carry comparable mutation burdens, suggesting that while cancers appear immortal, individual cancer cells may suffer diminished lifespan due to accrued mutation burden.

show abstract

A system to identify inhibitors of mTOR signaling using high-resolution growth analysis in Saccharomyces cerevisiae

Cited by 23 publications

References 81 publications

Genetic screen identifies adaptive aneuploidy as a key mediator of ER stress resistance in yeast

Genetic screen identifies adaptive aneuploidy as a key mediator of ER stress resistance in yeast

Nrf2 deficiency in aged mice exacerbates cellular senescence promoting cerebrovascular inflammation

Defining the impact of mutation accumulation on replicative lifespan in yeast using cancer-associated mutator phenotypes

Contact Info

Product

Resources

About