scholarly journals Relationship between the replicative age and cell volume in Saccharomyces cerevisiae.

2006 ◽  
Vol 53 (4) ◽  
pp. 747-751 ◽  
Author(s):  
Renata Zadrag ◽  
Magdalena Kwolek-Mirek ◽  
Grzegorz Bartosz ◽  
Tomasz Bilinski
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yeast Cell ◽  
Life Span ◽  
Cell Volume ◽  
Progressive Increase ◽  
Yeast Cells ◽  
Yeast Saccharomyces Cerevisiae ◽  
Replicative Life Span ◽  
Cell Divisions ◽  
Exact Relationship

Reaching the limit of cell divisions, a phenomenon referred to as replicative aging, of the yeast Saccharomyces cerevisiae involves a progressive increase in the cell volume. However, the exact relationship between the number of cell divisions accomplished (replicative age), the potential for further divisions and yeast cell volume has not been investigated thoroughly. In this study an increase of the yeast cell volume was achieved by treatment with pheromone alpha for up to 18 h. Plotting the number of cell divisions (replicative life span) of the pheromone-treated cells as a function of the cell volume attained during the treatment showed an inverse linear relationship. An analogous inverse relationship between the initial cell volume and replicative life span was found for the progeny of the pheromone-treated yeast. This phenomenon indicates that attaining an excessive volume may be a factor contributing to the limitation of cellular divisions of yeast cells.

scholarly journals Hypothesis: cell volume limits cell divisions.

2006 ◽  
Vol 53 (4) ◽  
pp. 833-835 ◽  
Author(s):  
Tomasz Biliński ◽  
Grzegorz Bartosz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Volume ◽  
Mammalian Cells ◽  
Somatic Cells ◽  
Large Cell ◽  
Yeast Cells ◽  
Replicative Aging ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cell Divisions

Mammalian somatic cells and also cells of the yeast Saccharomyces cerevisiae are capable of undergoing a limited number of divisions. Reaching the division limit is referred to, apparently not very fortunately, as replicative aging. A common feature of S. cerevisiae cells and fibroblasts approaching the limit of cell divisions in vitro is attaining giant volumes. In yeast cells this phenomenon is an inevitable consequence of budding so it is not causally related to aging. Therefore, reaching a critically large cell volume may underlie the limit of cell divisions. A similar phenomenon may limit the number of cell divisions of cultured mammalian cells. The term replicative (generative) aging may be therefore illegitimate.

scholarly journals Characteristics of the Recovery of the Coenzyme A-Synthesizing Protein Complex from Saccharomyces Cerevisiae

1979 ◽  
Author(s):  
◽  
Stanley Tarnowski ◽  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Yeast Cell ◽  
Protein Complex ◽  
Coenzyme A ◽  
Pantothenic Acid ◽  
Exchange Chromatography ◽  
Yeast Cells ◽  
Multienzyme Complex ◽  
Yeast Saccharomyces Cerevisiae

A multienzyme complex contained in Bakers' yeast (Saccharomyces cerevisiae) which synthesizes CoA has been named the coenzyme A-synthesizing protein complex (CoA-SPC). The CoA-SPC has been shown to be insoluble in the crude Bakers' yeast cell lysate formed by exposing the yeast cell to ether and dry ice. Only after solubilization has this multienzyme complex been shown to catalyze the formation of bound dephospho-CoA utilizing the substrates adenosine triphosphate, D-pantothenic acid and L-cysteine. A low molecular weight component or components of the soluble fraction of the yeast cell and chloride ion appears to be responsible for the solubilization of CoA-SPC. This endogenous component of the yeast cell is referred to as t-Factor. Purification of t-Factor has been accomplished by techniques which have included dialysis, ultrafiltration and paper, permeation, adsorption and ion-exchange chromatography. Although the t-Factor has not been identified, several properties have been demonstrated: (1) the molecular weight is between 400 to 1,000; (2) it is stable to heat at 80°C for 24 hours; (3) it is resistant to hydrolysis by trypsin and protease; (4) it is inactivated by ashing; and (5) has no ultraviolet absorption at 260 mu and 280 my. Replacement of t-Factor by commercially available compounds or solubilizing agents has failed to reveal its identity. A "one-step" purification of CoA-SPC may be obtained by combining partially purified t-Factor with insoluble yeast cell residue. An alternate procedure was developed for the preparation of CoA-SPC. This procedure involves the slow drying and rehydration of the yeast cells, but the need for t-Factor still remains. Sonic oscillation and passage through a french pressure cell, two of the more classical cell breakage techniques, fail to produce active CoA-SPC preparations.

scholarly journals Anhydrobiosis in Yeasts: Changes in Mitochondrial Membranes Improve the Resistance of Saccharomyces cerevisiae Cells to Dehydration–Rehydration

Fermentation ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 82 ◽  
Author(s):  
Galina Khroustalyova ◽  
Alexander Rapoport
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yeast Cell ◽  
Cell Survival ◽  
Yeast Species ◽  
Lithocholic Acid ◽  
Yeast Cells ◽  
Mitochondrial Membranes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Modern Biotechnology ◽  
Main Factors

Anhydrobiosis is a unique state of live organisms in which their metabolism is temporary reversibly suspended as the result of strong dehydration of their cells. This state is widely used currently during large-capacity production of active dry baker’s yeast. Other strains of the yeast Saccharomyces cerevisiae, as well as other yeast species that could potentially find use in modern biotechnology, are not resistant to dehydration–rehydration treatments. To improve their resistance, the main factors that influence cell survival during such treatment need to be revealed. This study showed the importance of mitochondria for yeast cell survival during transfer into anhydrobiosis, a factor that was strongly underestimated until this study. It was revealed that the external introduction inside yeast cells of 50 μM of lithocholic acid (LCA), an agent that induces changes in glycerophospholipids in mitochondrial membranes, in combination with 1% DMSO, may improve the survival rate of dehydrated cells. The influence of LCA upon yeast cell resistance to dehydration–rehydration was not linked with changes in the state of the cells’ plasma membrane.

scholarly journals Effect of stress on the life span of the yeast Saccharomyces cerevisiae.

2000 ◽  
Vol 47 (2) ◽  
pp. 355-364 ◽  
Author(s):  
A Swieciło ◽  
Z Krawiec ◽  
J Wawryn ◽  
G Bartosz ◽  
T Biliński
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Life Span ◽  
Yeast Cells ◽  
Wild Type ◽  
Maximum Life Span ◽  
Yeast Saccharomyces Cerevisiae ◽  
Yeast Strains ◽  
Resistance To Stress ◽  
The Mean ◽  
C 30

A correlation is known to exist in yeast and other organisms between the cellular resistance to stress and the life span. The aim of this study was to examine whether stress treatment does affect the generative life span of yeast cells. Both heat shock (38 degrees C, 30 min) and osmotic stress (0.3 M NaCl, 1 h) applied cyclically were found to increase the mean and maximum life span of Saccharomyces cerevisiae. Both effects were more pronounced in superoxide dismutase-deficient yeast strains (up to 50% prolongation of mean life span and up to 30% prolongation of maximum life span) than in their wild-type counterparts. These data point to the importance of the antioxidant barrier in the stress-induced prolongation of yeast life span.

scholarly journals A Mutation in the ATP2 Gene Abrogates the Age Asymmetry Between Mother and Daughter Cells of the Yeast Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 162 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Chi-Yung Lai ◽  
Ewa Jaruga ◽  
Corina Borghouts ◽  
S Michal Jazwinski
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Division ◽  
Life Span ◽  
Mother Cell ◽  
Yeast Cells ◽  
Mitochondrial Morphology ◽  
Temperature Sensitive ◽  
Yeast Saccharomyces Cerevisiae ◽  
Daughter Cells ◽  
Mother And Daughter

Abstract The yeast Saccharomyces cerevisiae reproduces by asymmetric cell division, or budding. In each cell division, the daughter cell is usually smaller and younger than the mother cell, as defined by the number of divisions it can potentially complete before it dies. Although individual yeast cells have a limited life span, this age asymmetry between mother and daughter ensures that the yeast strain remains immortal. To understand the mechanisms underlying age asymmetry, we have isolated temperature-sensitive mutants that have limited growth capacity. One of these clonal-senescence mutants was in ATP2, the gene encoding the β-subunit of mitochondrial F1, F0-ATPase. A point mutation in this gene caused a valine-to-isoleucine substitution at the ninetieth amino acid of the mature polypeptide. This mutation did not affect the growth rate on a nonfermentable carbon source. Life-span determinations following temperature shift-down showed that the clonal-senescence phenotype results from a loss of age asymmetry at 36°, such that daughters are born old. It was characterized by a loss of mitochondrial membrane potential followed by the lack of proper segregation of active mitochondria to daughter cells. This was associated with a change in mitochondrial morphology and distribution in the mother cell and ultimately resulted in the generation of cells totally lacking mitochondria. The results indicate that segregation of active mitochondria to daughter cells is important for maintenance of age asymmetry and raise the possibility that mitochondrial dysfunction may be a normal cause of aging. The finding that dysfunctional mitochondria accumulated in yeasts as they aged and the propensity for old mother cells to produce daughters depleted of active mitochondria lend support to this notion. We propose, more generally, that age asymmetry depends on partition of active and undamaged cellular components to the progeny and that this “filter” breaks down with age.

scholarly journals Pulsed Electric Field (PEF) Enhances Iron Uptake by the Yeast Saccharomyces cerevisiae

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 850
Author(s):  
Karolina Nowosad ◽  
Monika Sujka ◽  
Urszula Pankiewicz ◽  
Damijan Miklavčič ◽  
Marta Arczewska
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electric Field ◽  
Metal Ion ◽  
Treatment Time ◽  
Control Sample ◽  
Pulsed Electric Field ◽  
Yeast Cells ◽  
Iron Ions ◽  
Metal Ion Binding ◽  
Yeast Saccharomyces Cerevisiae

The aim of the study was to investigate the influence of a pulsed electric field (PEF) on the level of iron ion accumulation in Saccharomyces cerevisiae cells and to select PEF conditions optimal for the highest uptake of this element. Iron ions were accumulated most efficiently when their source was iron (III) nitrate. When the following conditions of PEF treatment were used: voltage 1500 V, pulse width 10 μs, treatment time 20 min, and a number of pulses 1200, accumulation of iron ions in the cells from a 20 h-culture reached a maximum value of 48.01 mg/g dry mass. Application of the optimal PEF conditions thus increased iron accumulation in cells by 157% as compared to the sample enriched with iron without PEF. The second derivative of the FTIR spectra of iron-loaded and -unloaded yeast cells allowed us to determine the functional groups which may be involved in metal ion binding. The exposure of cells to PEF treatment only slightly influenced the biomass and cell viability. However, iron-enriched yeast (both with or without PEF) showed lower fermentative activity than a control sample. Thus obtained yeast biomass containing a high amount of incorporated iron may serve as an alternative to pharmacological supplementation in the state of iron deficiency.

scholarly journals Loss of Ubp3 increases silencing, decreases unequal recombination in rDNA, and shortens the replicative life span in Saccharomyces cerevisiae

2014 ◽  
Vol 25 (12) ◽  
pp. 1916-1924 ◽  
Author(s):  
David Öling ◽  
Rehan Masoom ◽  
Kristian Kvint
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Life Span ◽  
Rna Polymerase Ii ◽  
Ribosomal Dna ◽  
Genetic Evidence ◽  
Wild Type ◽  
Replicative Life Span ◽  
Unequal Recombination

Ubp3 is a conserved ubiquitin protease that acts as an antisilencing factor in MAT and telomeric regions. Here we show that ubp3∆ mutants also display increased silencing in ribosomal DNA (rDNA). Consistent with this, RNA polymerase II occupancy is lower in cells lacking Ubp3 than in wild-type cells in all heterochromatic regions. Moreover, in a ubp3∆ mutant, unequal recombination in rDNA is highly suppressed. We present genetic evidence that this effect on rDNA recombination, but not silencing, is entirely dependent on the silencing factor Sir2. Further, ubp3∆ sir2∆ mutants age prematurely at the same rate as sir2∆ mutants. Thus our data suggest that recombination negatively influences replicative life span more so than silencing. However, in ubp3∆ mutants, recombination is not a prerequisite for aging, since cells lacking Ubp3 have a shorter life span than isogenic wild-type cells. We discuss the data in view of different models on how silencing and unequal recombination affect replicative life span and the role of Ubp3 in these processes.

The Cloning and Mapping of ADR6, a Gene Required for Sporulation and for Expression of the Alcohol Dehydrogenase II Isozyme From Saccharomyces cerevisiae

Genetics ◽  
1987 ◽  
Vol 116 (4) ◽  
pp. 531-540
Author(s):  
Aileen K W Taguchi ◽  
Elton T Young
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcohol Dehydrogenase ◽  
Single Gene ◽  
Carbon Sources ◽  
Transcription Unit ◽  
Yeast Cells ◽  
Recessive Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Upstream Activating Sequence ◽  
A Site

ABSTRACT The alcohol dehydrogenase II (ADH2) gene of the yeast, Saccharomyces cerevisiae, is not transcribed during growth on fermentable carbon sources such as glucose. Growth of yeast cells in a medium containing only nonfermentable carbon sources leads to a marked increase or derepression of ADH2 expression. The recessive mutation, adr6-1, leads to an inability to fully derepress ADH2 expression and to an inability to sporulate. The ADR6 gene product appears to act directly or indirectly on ADH2 sequences 3' to or including the presumptive TATAA box. The upstream activating sequence (UAS) located 5' to the TATAA box is not required for the Adr6- phenotype. Here, we describe the isolation of a recombinant plasmid containing the wild-type ADR6 gene. ADR6 codes for a 4.4-kb RNA which is present during growth both on glucose and on nonfermentable carbon sources. Disruption of the ADR6 transcription unit led to viable cells with decreased ADHII activity and an inability to sporulate. This indicates that both phenotypes result from mutations within a single gene and that the adr6-1 allele was representative of mutations at this locus. The ADR6 gene mapped to the left arm of chromosome XVI at a site 18 centimorgans from the centromere.

Identification of an upstream activating sequence and an upstream repressible sequence of the pyruvate kinase gene of the yeast Saccharomyces cerevisiae

1989 ◽  
Vol 9 (2) ◽  
pp. 442-451
Author(s):  
M Nishizawa ◽  
R Araki ◽  
Y Teranishi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Pyruvate Kinase ◽  
Transcriptional Activation ◽  
Regulatory Elements ◽  
Noncoding Region ◽  
Yeast Cells ◽  
Kinase Gene ◽  
Yeast Saccharomyces Cerevisiae ◽  
Upstream Activating Sequence

To clarify carbon source-dependent control of the glycolytic pathway in the yeast Saccharomyces cerevisiae, we have initiated a study of transcriptional regulation of the pyruvate kinase gene (PYK). By deletion analysis of the 5'-noncoding region of the PYK gene, we have identified an upstream activating sequence (UASPYK1) located between 634 and 653 nucleotides upstream of the initiating ATG codon. The promoter activity of the PYK 5'-noncoding region was abolished when the sequence containing the UASPYK1 was deleted from the region. Synthetic UASPYK1 (26mer), in either orientation, was able to restore the transcriptional activity of UAS-depleted mutants when placed upstream of the TATA sequence located at -199 (ATG as +1). While the UASPYK1 was required for basal to intermediate levels of transcriptional activation, a sequence between -714 and -811 was found to be necessary for full activation. On the other hand, a sequence between -344 and -468 was found to be responsible for transcriptional repression of the PYK gene when yeast cells were grown on nonfermentable carbon sources. This upstream repressible sequence also repressed transcription, although to a lesser extent, when glucose was present in the medium. The possible mechanism for carbon source-dependent regulation of PYK expression through these cis-acting regulatory elements is discussed.

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