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Kwolek-Mirek M, Dubicka-Lisowska A, Bednarska S, Zadrag-Tecza R, Kaszycki P. Changes in a Protein Profile Can Account for the Altered Phenotype of the Yeast Saccharomyces cerevisiae Mutant Lacking the Copper-Zinc Superoxide Dismutase. Metabolites 2023; 13:metabo13030459. [PMID: 36984899 PMCID: PMC10056615 DOI: 10.3390/metabo13030459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/14/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Copper-zinc superoxide dismutase (SOD1) is an antioxidant enzyme that catalyzes the disproportionation of superoxide anion to hydrogen peroxide and molecular oxygen (dioxygen). The yeast Saccharomyces cerevisiae lacking SOD1 (Δsod1) is hypersensitive to the superoxide anion and displays a number of oxidative stress-related alterations in its phenotype. We compared proteomes of the wild-type strain and the Δsod1 mutant employing two-dimensional gel electrophoresis and detected eighteen spots representing differentially expressed proteins, of which fourteen were downregulated and four upregulated. Mass spectrometry-based identification enabled the division of these proteins into functional classes related to carbon metabolism, amino acid and protein biosynthesis, nucleotide biosynthesis, and metabolism, as well as antioxidant processes. Detailed analysis of the proteomic data made it possible to account for several important morphological, biochemical, and physiological changes earlier observed for the SOD1 mutation. An example may be the proposed additional explanation for methionine auxotrophy. It is concluded that protein comparative profiling of the Δsod1 yeast may serve as an efficient tool in the elucidation of the mutation-based systemic alterations in the resultant S. cerevisiae phenotype.
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Affiliation(s)
- Magdalena Kwolek-Mirek
- Department of Biology, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszow, 35-601 Rzeszow, Poland
| | - Aleksandra Dubicka-Lisowska
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, 31-425 Krakow, Poland
| | - Sabina Bednarska
- Department of Biology, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszow, 35-601 Rzeszow, Poland
| | - Renata Zadrag-Tecza
- Department of Biology, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszow, 35-601 Rzeszow, Poland
| | - Pawel Kaszycki
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, 31-425 Krakow, Poland
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Boulton C. Provocation: all yeast cells are born equal, but some grow to be more equal than others. JOURNAL OF THE INSTITUTE OF BREWING 2021. [DOI: 10.1002/jib.647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Smith JT, White JW, Dungrawala H, Hua H, Schneider BL. Yeast lifespan variation correlates with cell growth and SIR2 expression. PLoS One 2018; 13:e0200275. [PMID: 29979754 PMCID: PMC6034835 DOI: 10.1371/journal.pone.0200275] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/22/2018] [Indexed: 11/19/2022] Open
Abstract
Isogenic wild type yeast cells raised in controlled environments display a significant range of lifespan variation. Recent microfluidic studies suggest that differential growth or gene expression patterns may explain some of the heterogeneity of aging assays. Herein, we sought to complement this work by similarly examining a large set of replicative lifespan data from traditional plate assays. In so doing, we reproduced the finding that short-lived cells tend to arrest at senescence with a budded morphology. Further, we found that wild type cells born unusually small did not have an extended lifespan. However, large birth size and/or high inter-generational growth rates significantly correlated with a reduced lifespan. Finally, we found that SIR2 expression levels correlated with lifespan and intergenerational growth. SIR2 expression was significantly reduced in large cells and increased in small wild type cells. A moderate increase in SIR2 expression correlated with reduced growth, decreased proliferation and increased lifespan in plate aging assays. We conclude that cellular growth rates and SIR2 expression levels may contribute to lifespan variation in individual cells.
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Affiliation(s)
- Jessica T. Smith
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
| | - Jill W. White
- Center for the Integration of STEM Education & Research, Texas Tech University, Lubbock, TX, United States of America
| | - Huzefa Dungrawala
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, United States of America
| | - Hui Hua
- Department of Medical Education, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
| | - Brandt L. Schneider
- Department of Medical Education, Texas Tech University Health Sciences Center, Lubbock, TX, United States of America
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4
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Abstract
Usually, cells balance their growth with their division. Coordinating growth inputs with cell division ensures the proper timing of division when sufficient cell material is available and affects the overall rate of cell proliferation. At a very fundamental level, cellular replicative lifespan-defined as the number of times a cell can divide, is a manifestation of cell cycle control. Hence, control of mitotic cell divisions, especially when the commitment is made to a new round of cell division, is intimately linked to replicative aging of cells. In this chapter, we review our current understanding, and its shortcomings, of how unbalanced growth and division, can dramatically influence the proliferative potential of cells, often leading to cellular and organismal aging phenotypes. The interplay between growth and division also underpins cellular senescence (i.e., inability to divide) and quiescence, when cells exit the cell cycle but still retain their ability to divide.
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Janssens GE, Veenhoff LM. The Natural Variation in Lifespans of Single Yeast Cells Is Related to Variation in Cell Size, Ribosomal Protein, and Division Time. PLoS One 2016; 11:e0167394. [PMID: 27907085 PMCID: PMC5132237 DOI: 10.1371/journal.pone.0167394] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 11/14/2016] [Indexed: 12/30/2022] Open
Abstract
There is a large variability in lifespans of individuals even if they are genetically identical and raised under the same environmental conditions. Our recent system wide study of replicative aging in baker’s yeast predicts that protein biogenesis is a driver of aging. Here, we address how the natural variation in replicative lifespan within wild-type populations of yeast cells correlates to three biogenesis-related parameters, namely cell size, ribosomal protein Rpl13A-GFP levels, and division times. Imaging wild type yeast cells in microfluidic devices we observe that in all cells and at all ages, the division times as well as the increase in cell size that single yeast undergo while aging negatively correlate to their lifespan. In the longer-lived cells Rpl13A-GFP levels also negatively correlate to lifespan. Interestingly however, at young ages in the population, ribosome concentration was lowest in the cells that increased the most in size and had shorter lifespans. The correlations between these molecular and cellular properties related to biogenesis and lifespan explain a small portion of the variation in lifespans of individual cells, consistent with the highly individual and multifactorial nature of aging.
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Affiliation(s)
- Georges E. Janssens
- European Research Institute for the Biology of Ageing, University of Groningen University Medical Centre Groningen, Groningen, The Netherlands
| | - Liesbeth M. Veenhoff
- European Research Institute for the Biology of Ageing, University of Groningen University Medical Centre Groningen, Groningen, The Netherlands
- * E-mail:
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Smith J, Wright J, Schneider BL. A budding yeast's perspective on aging: the shape I'm in. Exp Biol Med (Maywood) 2015; 240:701-10. [PMID: 25819684 DOI: 10.1177/1535370215577584] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Aging is exemplified by progressive, deleterious changes that increase the probability of death. However, while the effects of age are easy to recognize, identification of the processes involved has proved to be much more difficult. Somewhat surprisingly, research using the budding yeast has had a profound impact on our current understanding of the mechanisms involved in aging. Herein, we examine the biological significance and implications surrounding the observation that genetic pathways involved in the modulation of aging and the determination of lifespan in yeast are highly complicated and conserved.
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Affiliation(s)
- Jessica Smith
- Department of Medical Education and Department of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Jill Wright
- Department of Medical Education and Department of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Brandt L Schneider
- Department of Medical Education and Department of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
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7
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He C, Tsuchiyama SK, Nguyen QT, Plyusnina EN, Terrill SR, Sahibzada S, Patel B, Faulkner AR, Shaposhnikov MV, Tian R, Tsuchiya M, Kaeberlein M, Moskalev AA, Kennedy BK, Polymenis M. Enhanced longevity by ibuprofen, conserved in multiple species, occurs in yeast through inhibition of tryptophan import. PLoS Genet 2014; 10:e1004860. [PMID: 25521617 PMCID: PMC4270464 DOI: 10.1371/journal.pgen.1004860] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 10/29/2014] [Indexed: 11/29/2022] Open
Abstract
The common non-steroidal anti-inflammatory drug ibuprofen has been associated with a reduced risk of some age-related pathologies. However, a general pro-longevity role for ibuprofen and its mechanistic basis remains unclear. Here we show that ibuprofen increased the lifespan of Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster, indicative of conserved eukaryotic longevity effects. Studies in yeast indicate that ibuprofen destabilizes the Tat2p permease and inhibits tryptophan uptake. Loss of Tat2p increased replicative lifespan (RLS), but ibuprofen did not increase RLS when Tat2p was stabilized or in an already long-lived strain background impaired for aromatic amino acid uptake. Concomitant with lifespan extension, ibuprofen moderately reduced cell size at birth, leading to a delay in the G1 phase of the cell cycle. Similar changes in cell cycle progression were evident in a large dataset of replicatively long-lived yeast deletion strains. These results point to fundamental cell cycle signatures linked with longevity, implicate aromatic amino acid import in aging and identify a largely safe drug that extends lifespan across different kingdoms of life. Aging is the greatest risk factor for many diseases, which together account for the majority of global deaths and healthcare costs. Here we show that the common drug ibuprofen increases the lifespan of yeast, worms and flies, indicative of conserved longevity effects. In budding yeast, an excellent model of cellular longevity mechanisms, ibuprofen's pro-longevity action is independent of its known anti-inflammatory role. We show that the critical function of ibuprofen in longevity is to inhibit the uptake of aromatic amino acids, by destabilizing the high-affinity tryptophan permease. We further show that ibuprofen alters cell cycle progression. Mirroring the effects of ibuprofen, we found that most yeast long-lived mutants were also similarly affected in cell cycle progression. These findings identify a safe drug that extends the lifespan of divergent organisms and reveal fundamental cellular properties associated with longevity.
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Affiliation(s)
- Chong He
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Scott K. Tsuchiyama
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Quynh T. Nguyen
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Ekaterina N. Plyusnina
- Institute of Biology of Komi Science Center of Ural Branch of RAS, Syktyvkar, Russia
- Syktyvkar State University, Syktyvkar, Russia
| | - Samuel R. Terrill
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Sarah Sahibzada
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
| | - Bhumil Patel
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Alena R. Faulkner
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Mikhail V. Shaposhnikov
- Institute of Biology of Komi Science Center of Ural Branch of RAS, Syktyvkar, Russia
- Syktyvkar State University, Syktyvkar, Russia
| | - Ruilin Tian
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Mitsuhiro Tsuchiya
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Matt Kaeberlein
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Alexey A. Moskalev
- Institute of Biology of Komi Science Center of Ural Branch of RAS, Syktyvkar, Russia
- Syktyvkar State University, Syktyvkar, Russia
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | - Brian K. Kennedy
- Buck Institute for Research on Aging, Novato, California, United States of America
- * E-mail: (BKK); (MP)
| | - Michael Polymenis
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, United States of America
- * E-mail: (BKK); (MP)
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Corrêa LFDM, Passos FJV, Viloria MIV, Martins Filho OA, de Carvalho AT, Passos FML. Signals of aging associated with lower growth rates in Kluyveromyces lactis cultures under nitrogen limitation. Can J Microbiol 2014; 60:605-12. [PMID: 25204685 DOI: 10.1139/cjm-2014-0236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of aging on the specific growth rate of Kluyveromyces lactis cultures, as a function of (NH4)2SO4 concentration, were evaluated. The growth kinetic parameters maximum specific growth rate and saturation constant for (NH4)2SO4 were calculated to be 0.44 h(-1) and 0.15 mmol·L(-1), respectively. Batch cultures were allowed to age for 16 days without influence of cell density or starvation. The specific growth rates of these cultures were determined each day and decreased as the population aged at different nitrogen concentrations. Aging signals (N-acetylglucosamine content of the cell wall, cell dimensions, and apoptosis markers) were measured. Apoptosis markers were detected after 5 days at limiting (NH4)2SO4 concentrations (0.57, 3.80, and 7.60 mmol·L(-1)) but only after 8 days at a nonlimiting (NH4)2SO4 concentration (38.0 mmol·L(-1)). Similarly, continuous cultures of K. lactis performed under nitrogen limitation and, at lower dilution rates, accumulated cells exhibiting aging signals. The results demonstrate that aging affects growth rate and raise the question of whether nitrogen limitation accelerates aging. Because aging is correlated with growth rate, and each dilution rate of the continuous cultures tends to select and accumulate cells with a respective age, cultures growing at lower growth rates can be useful to investigate yeast physiological responses, including aging.
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Affiliation(s)
- Lygia Fátima da Mata Corrêa
- a Departamento de Microbiologia, Universidade Federal de Viçosa, Av. P.H. Rolfs s/n 36571-000, Laboratório de Fisiologia de Microrganismos, BIOAGRO, Viçosa - MG, Brasil
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9
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Coelho M, Dereli A, Haese A, Kühn S, Malinovska L, DeSantis ME, Shorter J, Alberti S, Gross T, Tolić-Nørrelykke IM. Fission yeast does not age under favorable conditions, but does so after stress. Curr Biol 2013; 23:1844-52. [PMID: 24035542 DOI: 10.1016/j.cub.2013.07.084] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 07/14/2013] [Accepted: 07/29/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND Many unicellular organisms age: as time passes, they divide more slowly and ultimately die. In budding yeast, asymmetric segregation of cellular damage results in aging mother cells and rejuvenated daughters. We hypothesize that the organisms in which this asymmetry is lacking, or can be modulated, may not undergo aging. RESULTS We performed a complete pedigree analysis of microcolonies of the fission yeast Schizosaccharomyces pombe growing from a single cell. When cells were grown under favorable conditions, none of the lineages exhibited aging, which is defined as a consecutive increase in division time and increased death probability. Under favorable conditions, few cells died, and their death was random and sudden rather than following a gradual increase in division time. Cell death correlated with the inheritance of Hsp104-associated protein aggregates. After stress, the cells that inherited large aggregates aged, showing a consecutive increase in division time and an increased death probability. Their sisters, who inherited little or no aggregates, did not age. CONCLUSIONS We conclude that S. pombe does not age under favorable growth conditions, but does so under stress. This transition appears to be passive rather than active and results from the formation of a single large aggregate, which segregates asymmetrically at the subsequent cell division. We argue that this damage-induced asymmetric segregation has evolved to sacrifice some cells so that others may survive unscathed after severe environmental stresses.
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Affiliation(s)
- Miguel Coelho
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
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Wright J, Dungrawala H, Bright RK, Schneider BL. A growing role for hypertrophy in senescence. FEMS Yeast Res 2012; 13:2-6. [PMID: 23107076 DOI: 10.1111/1567-1364.12015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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11
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Biliński T, Zadrąg-Tęcza R, Bartosz G. Hypertrophy hypothesis as an alternative explanation of the phenomenon of replicative aging of yeast. FEMS Yeast Res 2011; 12:97-101. [PMID: 22093953 DOI: 10.1111/j.1567-1364.2011.00759.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 10/28/2011] [Indexed: 01/28/2023] Open
Abstract
This paper summarizes numerous arguments demonstrating that the hypothesis of accumulation of the senescence factor, which was the basis for introducing yeast to the group of model organisms of gerontology, finds no experimental support. Among several candidates for the role of the causative agents of replicative aging, only one - hypertrophy - always accompanies symptoms of aging, not only in Saccharomyces cerevisiae, but also in Schizosaccharomyces pombe.
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Affiliation(s)
- Tomasz Biliński
- Department of Biochemistry and Cell Biology, University of Rzeszów, Rzeszów, Poland.
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12
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Yang J, Dungrawala H, Hua H, Manukyan A, Abraham L, Lane W, Mead H, Wright J, Schneider BL. Cell size and growth rate are major determinants of replicative lifespan. Cell Cycle 2011; 10:144-55. [PMID: 21248481 DOI: 10.4161/cc.10.1.14455] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Yeast cells, like mammalian cells, enlarge steadily as they age. Unabated cell growth can promote cellular senescence; however, the significance of the relationship between size and cellular lifespan is not well understood. Herein, we report a genetic link between cell size, growth rate and lifespan. Mutations that increase cell size concomitantly increase growth rate and decrease lifespan. As a result, large cells grow, divide and age dramatically faster than small cells. Conversely, small cell mutants age slowly and are long-lived. Investigation of the mechanisms involved suggests that attainment of a maximal size modulates lifespan. Indeed, cumulative results revealed that life expectancy is size-dependent, and that the rate at which cells age is determined in large part by the amount of cell growth per generation.
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Affiliation(s)
- Jingye Yang
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA
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13
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Sun J, Stowers CC, Boczko EM, Li D. Measurement of the volume growth rate of single budding yeast with the MOSFET-based microfluidic Coulter counter. LAB ON A CHIP 2010; 10:2986-93. [PMID: 20717618 PMCID: PMC3468151 DOI: 10.1039/c005029f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We report on measurements of the volume growth rate of ten individual budding yeast cells using a recently developed MOSFET-based microfluidic Coulter counter. The MOSFET-based microfluidic Coulter counter is very sensitive, provides signals that are immune from the baseline drift, and can work with cell culture media of complex composition. These desirable features allow us to directly measure the volume growth rate of single cells of Saccharomyces cerevisiae LYH3865 strain budding yeast in YNB culture media over a whole cell cycle. Results indicate that all budding yeast follow a sigmoid volume growth profile with reduced growth rates at the initial stage before the bud emerges and the final stage after the daughter gets mature. Analysis of the data indicates that even though all piecewise linear, Gomperitz, and Hill's function models can fit the global growth profile equally well, the data strongly support local exponential growth phenomenon. Accurate volume growth measurements are important for applications in systems biology where quantitative parameters are required for modeling and simulation.
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Affiliation(s)
- Jiashu Sun
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, 37235-1592, USA.
| | - Chris C. Stowers
- Department of Bioprocess R&D, Dow AgroSciences LLC, Indianapolis, IN, 46268-1054, USA
| | - Erik M. Boczko
- Department of Biomedical Informatics, Vanderbilt University, Nashville, TN, 37235-1592, USA
| | - Deyu Li
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, 37235-1592, USA.
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14
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Boczko EM, Stowers CC, Gedeon T, Young TR. ODE, RDE and SDE models of cell cycle dynamics and clustering in yeast. JOURNAL OF BIOLOGICAL DYNAMICS 2010; 4:328-45. [PMID: 20563236 PMCID: PMC2885793 DOI: 10.1080/17513750903288003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Biologists have long observed periodic-like oxygen consumption oscillations in yeast populations under certain conditions, and several unsatisfactory explanations for this phenomenon have been proposed. These ‘autonomous oscillations’ have often appeared with periods that are nearly integer divisors of the calculated doubling time of the culture. We hypothesize that these oscillations could be caused by a form of cell cycle synchronization that we call clustering. We develop some novel ordinary differential equation models of the cell cycle. For these models, and for random and stochastic perturbations, we give both rigorous proofs and simulations showing that both positive and negative growth rate feedback within the cell cycle are possible agents that can cause clustering of populations within the cell cycle. It occurs for a variety of models and for a broad selection of parameter values. These results suggest that the clustering phenomenon is robust and is likely to be observed in nature. Since there are necessarily an integer number of clusters, clustering would lead to periodic-like behaviour with periods that are nearly integer divisors of the period of the cell cycle. Related experiments have shown conclusively that cell cycle clustering occurs in some oscillating yeast cultures.
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Affiliation(s)
- Erik M. Boczko
- Department of Biomedical Informatics, Vanderbilt University
| | | | - Tomas Gedeon
- Department of Mathematics, Montana State University
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15
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Cell size regulation during telomere-directed senescence in Saccharomyces cerevisiae. Biosci Biotechnol Biochem 2010; 74:195-8. [PMID: 20057141 DOI: 10.1271/bbb.90627] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
DNA replication without telomerase leads to telomere shortening and induces replicative senescence. We found that in a telomerase-deficient budding yeast mutant, the volume of each telomere-shortened cell increased as its growth capacity decreased, and that this process was associated with changes in vacuolar morphology. Senescence-induced cell expansion required Mec1, a DNA damage-responsive kinase, but not vacuolar SNARE Vam3.
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16
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Abstract
It is commonly assumed that growth and aging are somehow linked, but the nature of this link has been elusive. Here we review the aging process as a continuation of TOR-driven growth. TOR is absolutely essential for developmental growth, but upon completion of development it causes aging and age-related diseases. Thus, the nutrient-sensing and growth-promoting TOR signaling pathway may provide a molecular link between growth and aging that is universal from yeast to human.
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17
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Zadrag-Tecza R, Kwolek-Mirek M, Bartosz G, Bilinski T. Cell volume as a factor limiting the replicative lifespan of the yeast Saccharomyces cerevisiae. Biogerontology 2008; 10:481-8. [DOI: 10.1007/s10522-008-9192-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2008] [Accepted: 10/16/2008] [Indexed: 10/21/2022]
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18
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Blagosklonny MV. Program-like aging and mitochondria: instead of random damage by free radicals. J Cell Biochem 2008; 102:1389-99. [PMID: 17975792 DOI: 10.1002/jcb.21602] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
As recently suggested, the target of rapamycin (TOR) pathway, rather than molecular damage by free radicals, drives aging and diseases of aging. But may mitochondria nevertheless contribute to aging? Here, I discuss aimless program-like aging (versus altruistic program), conflict between the cell and mitochondria, cell murder (versus cell suicide) and the role of mitochondria in aging. In particular, life-long selection among mitochondria may yield "selfish" (malignant) mitochondria resistant to autophagy. And TOR may create an intra-cellular environment that is permissive for such selfish mitochondria. In theory, pharmacologic inhibitors of the TOR pathway may reverse accumulation of defective mitochondria, while also inhibiting the aging process.
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Affiliation(s)
- Mikhail V Blagosklonny
- Cancer Center, Ordway Research Institute, 150 New Scotland Ave, and Oncotarget, Albany, New York 12208, USA.
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19
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Yiu G, McCord A, Wise A, Jindal R, Hardee J, Kuo A, Shimogawa MY, Cahoon L, Wu M, Kloke J, Hardin J, Hoopes LLM. Pathways change in expression during replicative aging in Saccharomyces cerevisiae. J Gerontol A Biol Sci Med Sci 2008; 63:21-34. [PMID: 18245757 PMCID: PMC2562229 DOI: 10.1093/gerona/63.1.21] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
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 quantitative real-time reverse-transcription polymerase chain reaction (qPCR) has shown reproducible, statistically significant changes in messenger RNA (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 findings include a pseudostationary phase, downregulation of methylation-related metabolism, increased nucleotide excision repair-related mRNA, and a strong upregulation 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.
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Affiliation(s)
- Gloria Yiu
- Department of Biology, Pomona College, Claremont, California
| | | | - Alison Wise
- Department of Mathematics, Pomona College, Claremont, California
| | - Rishi Jindal
- Department of Biology, Pomona College, Claremont, California
| | - Jennifer Hardee
- Department of Biology, Pomona College, Claremont, California
| | - Allen Kuo
- Department of Biology, Pomona College, Claremont, California
| | | | - Laty Cahoon
- Department of Biology, Pomona College, Claremont, California
| | - Michelle Wu
- Department of Biology, Pomona College, Claremont, California
| | - John Kloke
- Department of Mathematics, Pomona College, Claremont, California
| | - Johanna Hardin
- Department of Mathematics, Pomona College, Claremont, California
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Henderson GP, Gan L, Jensen GJ. 3-D ultrastructure of O. tauri: electron cryotomography of an entire eukaryotic cell. PLoS One 2007; 2:e749. [PMID: 17710148 PMCID: PMC1939878 DOI: 10.1371/journal.pone.0000749] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Accepted: 07/16/2007] [Indexed: 01/11/2023] Open
Abstract
The hallmark of eukaryotic cells is their segregation of key biological functions into discrete, membrane-bound organelles. Creating accurate models of their ultrastructural complexity has been difficult in part because of the limited resolution of light microscopy and the artifact-prone nature of conventional electron microscopy. Here we explored the potential of the emerging technology electron cryotomography to produce three-dimensional images of an entire eukaryotic cell in a near-native state. Ostreococcus tauri was chosen as the specimen because as a unicellular picoplankton with just one copy of each organelle, it is the smallest known eukaryote and was therefore likely to yield the highest resolution images. Whole cells were imaged at various stages of the cell cycle, yielding 3-D reconstructions of complete chloroplasts, mitochondria, endoplasmic reticula, Golgi bodies, peroxisomes, microtubules, and putative ribosome distributions in-situ. Surprisingly, the nucleus was seen to open long before mitosis, and while one microtubule (or two in some predivisional cells) was consistently present, no mitotic spindle was ever observed, prompting speculation that a single microtubule might be sufficient to segregate multiple chromosomes.
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Affiliation(s)
- Gregory P. Henderson
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
| | - Lu Gan
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
| | - Grant J. Jensen
- Division of Biology, California Institute of Technology, Pasadena, California, United States of America
- * To whom correspondence should be addressed. E-mail:
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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