scholarly journals Formation of intracellular glutamine synthetase bodies depends strongly upon cellular age and glucose availability

2014 ◽  
Author(s):  
Jeremy O'Connell ◽  
Mark Tsechansky ◽  
Marguerite West-Driga ◽  
Edward M Marcotte
Keyword(s):  
Glutamine Synthetase ◽  
Quantitative Measurement ◽  
Competitive Inhibitor ◽  
Yeast Cells ◽  
Ammonia Assimilation ◽  
Body Formation ◽  
Daughter Cells ◽  
Cell Age ◽  
Mother Cells

The enzyme glutamine synthetase serves key roles in central nitrogen metabolism, catalyzing the biosynthesis of glutamine, as well as regulating ammonia assimilation and integrating metabolic signals to balance nitrogen use. The budding yeast enzyme was recently found to form intracellular bodies (GS bodies) composed of glutamine synthetase and Hsp90 chaperones following various types of nutrient depletion or chemical stress. In order to better quantify and characterize the in vivo formation of GS bodies, we developed an assay for their formation in single yeast cells using imaging flow cytometry, which enables the quantitative measurement of rates of GS body formation and their population penetrance. Either reduction of supplied glucose, or addition of the competitive inhibitor of glycolysis, 2-deoxyglucose, markedly enhanced the formation of GS bodies. The occurrence of GS bodies increased with increasing cell size, a proxy for cell age, while treatment with rapamycin antagonized their formation. Direct measurement of GS body formation as a function of replicative age showed that mother cells exhibited a significantly higher incidence of GS bodies than daughter cells, and the frequency of GS body formation increased with increasing replicative cell age. Thus, we find that yeast glutamine synthetase bodies form in a manner strongly dependent on available glucose and increase markedly with cell age.

scholarly journals Formation of intracellular glutamine synthetase bodies depends strongly upon cellular age and glucose availability

2014 ◽  
Author(s):  
Jeremy O'Connell ◽  
Mark Tsechansky ◽  
Marguerite West-Driga ◽  
Edward M Marcotte
Keyword(s):  
Glutamine Synthetase ◽  
Quantitative Measurement ◽  
Competitive Inhibitor ◽  
Yeast Cells ◽  
Ammonia Assimilation ◽  
Body Formation ◽  
Daughter Cells ◽  
Cell Age ◽  
Mother Cells

The enzyme glutamine synthetase serves key roles in central nitrogen metabolism, catalyzing the biosynthesis of glutamine, as well as regulating ammonia assimilation and integrating metabolic signals to balance nitrogen use. The budding yeast enzyme was recently found to form intracellular bodies (GS bodies) composed of glutamine synthetase and Hsp90 chaperones following various types of nutrient depletion or chemical stress. In order to better quantify and characterize the in vivo formation of GS bodies, we developed an assay for their formation in single yeast cells using imaging flow cytometry, which enables the quantitative measurement of rates of GS body formation and their population penetrance. Either reduction of supplied glucose, or addition of the competitive inhibitor of glycolysis, 2-deoxyglucose, markedly enhanced the formation of GS bodies. The occurrence of GS bodies increased with increasing cell size, a proxy for cell age, while treatment with rapamycin antagonized their formation. Direct measurement of GS body formation as a function of replicative age showed that mother cells exhibited a significantly higher incidence of GS bodies than daughter cells, and the frequency of GS body formation increased with increasing replicative cell age. Thus, we find that yeast glutamine synthetase bodies form in a manner strongly dependent on available glucose and increase markedly with cell age.

scholarly journals A KDM5-Prospero transcriptional axis functions during early neurodevelopment to regulate mushroom body formation

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Hayden AM Hatch ◽  
Helen M Belalcazar ◽  
Owen J Marshall ◽  
Julie Secombe
Keyword(s):  
Transcription Factor ◽  
Mushroom Body ◽  
Transcriptional Regulators ◽  
Histone Demethylase ◽  
Body Formation ◽  
Demethylase Activity ◽  
Mother Cells ◽  
Lysine Demethylase ◽  
Canonical Histone

Mutations in the lysine demethylase 5 (KDM5) family of transcriptional regulators are associated with intellectual disability, yet little is known regarding their spatiotemporal requirements or neurodevelopmental contributions. Utilizing the mushroom body (MB), a major learning and memory center within the Drosophila brain, we demonstrate that KDM5 is required within ganglion mother cells and immature neurons for proper axogenesis. Moreover, the mechanism by which KDM5 functions in this context is independent of its canonical histone demethylase activity. Using in vivo transcriptional and binding analyses, we identify a network of genes directly regulated by KDM5 that are critical modulators of neurodevelopment. We find that KDM5 directly regulates the expression of prospero, a transcription factor that we demonstrate is essential for MB morphogenesis. Prospero functions downstream of KDM5 and binds to approximately half of KDM5-regulated genes. Together, our data provide evidence for a KDM5-Prospero transcriptional axis that is essential for proper MB development.

scholarly journals An Exclusively Nuclear RNA-Binding Protein Affects Asymmetric Localization of ASH1 mRNA and Ash1p in Yeast

2001 ◽  
Vol 153 (2) ◽  
pp. 307-318 ◽  
Author(s):  
Roy M. Long ◽  
Wei Gu ◽  
Xiuhua Meng ◽  
Graydon Gonsalvez ◽  
Robert H. Singer ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Localization ◽  
Yeast Cells ◽  
Rna Structures ◽  
Nuclear Factors ◽  
Mother Cells ◽  
Ash1 Mrna

The localization of ASH1 mRNA to the distal tip of budding yeast cells is essential for the proper regulation of mating type switching in Saccharomyces cerevisiae. A localization element that is predominantly in the 3′-untranslated region (UTR) can direct this mRNA to the bud. Using this element in the three-hybrid in vivo RNA-binding assay, we identified a protein, Loc1p, that binds in vitro directly to the wild-type ASH1 3′-UTR RNA, but not to a mutant RNA incapable of localizing to the bud nor to several other mRNAs. LOC1 codes for a novel protein that recognizes double-stranded RNA structures and is required for efficient localization of ASH1 mRNA. Accordingly, Ash1p gets symmetrically distributed between daughter and mother cells in a loc1 strain. Surprisingly, Loc1p was found to be strictly nuclear, unlike other known RNA-binding proteins involved in mRNA localization which shuttle between the nucleus and the cytoplasm. We propose that efficient cytoplasmic ASH1 mRNA localization requires a previous interaction with specific nuclear factors.

Difference in generation times for mother and daughter cells in yeasts

1978 ◽  
Vol 24 (7) ◽  
pp. 827-833 ◽  
Author(s):  
T. W. Flegel
Keyword(s):  
Growth Characteristic ◽  
Time Lapse ◽  
Yeast Cells ◽  
Daughter Cells ◽  
Yeast Strains ◽  
Generation Times ◽  
Spot Check ◽  
Mother And Daughter ◽  
The Mean ◽  
Mother Cells

Fruitless attempts to synchronize haploid yeast cells from the Phragmobasidiomycete Sirobasidium magnum led to the discovery that the mother and daughter cells (MDC) had greatly different generation times. Time-lapse photographic sequences of budding showed that the mean generation time for daughter cells was more than three times greater than that for mother cells. This growth characteristic could be determined by a spot check of the microcolony pattern on agar. Using such a check, yeast strains of Rhodotorula (Rhodosporidium) and Cryptococcus that were tested demonstrated relative MDC equivalence while those of Sporobolomyces, Bullera, and Tremella showed MDC non-equivalence in varying degrees.

scholarly journals Age-induced P-bodies become detrimental and shorten the lifespan of yeast

2021 ◽  
Author(s):  
Joonhyuk Choi ◽  
Shuhao Wang ◽  
Yang Li ◽  
Nan Hao ◽  
Brian M Zid
Keyword(s):  
Irreversible Process ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Model System ◽  
Yeast Cells ◽  
P Bodies ◽  
Daughter Cells ◽  
Progressive Loss ◽  
External Stresses ◽  
Mother Cells

Aging is an irreversible process characterized by a progressive loss of homeostasis in cells, which often manifests as protein aggregates. Recently, it has been speculated that aggregates of RNA-binding proteins (RBPs) may go through pathological transitions during aging and drive the progression of age-associated neurodegenerative diseases. Using Saccharomyces cerevisiae as a model system of aging, we find that P-bodies - an RBP granule that is formed and can be beneficial for cell growth during stress conditions - naturally form during aging without any external stresses and an increase in P-body intensity is negatively correlated with the future lifespan of yeast cells. When mother cells transfer age-induced P-bodies to daughter cells, the mother cells extend lifespan, while the daughter cells grow poorly, suggesting that these age-induced P-bodies may be directly pathological. Furthermore, we find that suppressing acidification of the cytosol during aging slows down the increase in the intensity of P-body foci and extends lifespan. Our data suggest that acidification of the cytosol may facilitate the pathological transition of RBP granules during aging.

Chitin scar breaks in aged Saccharomyces cerevisiae

Microbiology ◽  
2003 ◽  
Vol 149 (11) ◽  
pp. 3129-3137 ◽  
Author(s):  
Chris D. Powell ◽  
David E. Quain ◽  
Katherine A. Smart
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Surface ◽  
Daughter Cell ◽  
Scar Tissue ◽  
Daughter Cells ◽  
Cell Age ◽  
Mother And Daughter ◽  
A Cell ◽  
Cell Surface Changes ◽  
Mother Cells

Ageing in budding yeast is not determined by chronological lifespan, but by the number of times an individual cell is capable of dividing, termed its replicative capacity. As cells age they are subject to characteristic cell surface changes. Saccharomyces cerevisiae reproduces asexually by budding and as a consequence of this process both mother and daughter cell retain chitinous scar tissue at the point of cytokinesis. Daughter cells exhibit a frail structure known as the birth scar, while mother cells display a more persistent bud scar. The number of bud scars present on the cell surface is directly related to the number of times a cell has divided and thus constitutes a biomarker for replicative cell age. It has been proposed that the birth scar may be subject to stretching caused by expansion of the daughter cell; however, no previous analysis of the effect of cell age on birth or bud scar size has been reported. This paper provides evidence that scar tissue expands with the cell during growth. It is postulated that symmetrically arranged breaks in the bud scar allow these rigid chitinous structures to expand without compromising cellular integrity.

scholarly journals A mechanism to prevent transformation of the Whi3 mnemon into a prion

2020 ◽  
Author(s):  
Yasmin Lau ◽  
Iuliia Parfenova ◽  
Juha Saarikangas ◽  
Richard A. Nichols ◽  
Yves Barral ◽  
...  
Keyword(s):  
Mother Cell ◽  
Temporal Stability ◽  
Structural Features ◽  
Yeast Cells ◽  
Membrane Diffusion ◽  
Cell Cycles ◽  
Daughter Cells ◽  
Cycle Arrest ◽  
Mother Cells

AbstractIn response to deceptive courtship, budding yeast cells escape pheromone induced cell cycle arrest through coalescence of the G1/S inhibitor Whi3 into a dominant inactive super-assembly. Strikingly, Whi3 super-assemblies remain stable over many cell cycles in the mother cells and are not passed on to the daughter cells. Thereby, Whi3 coalescence encodes memory, conferring to it the property of a mnemon (Whi3mnem), a protein which conformational change maintain a trait that is permanent in the mother cell but is not inherited by daughter cells. Mnemons share structural features with prions, which are self-templating protein conformations that are inherited by daughter cells. Yet, how the maintenance and asymmetric inheritance of Whi3mnem are achieved is unknown. Here, we report that Whi3mnem is closely associated with endoplasmic reticulum (ER) membranes and retained in the mother cell by the presence of lateral membrane diffusion barriers at the bud neck. Strikingly, barrier defects made Whi3mnem propagate in a mitotically stable manner, like a prion. Alike Whi3mnem, transformation of Whi3 into a prion required its poly-glutamine prion-like domain. Thus, we propose that Whi3mnem is in a self-templating state, lending temporal stability to the memory that it encodes, while its anchorage into the compartmentalized membranes of the ER ensures its confinement in the mother cell and prevents its infectious propagation. These results suggest that confined self-templating super-assembly is a powerful mechanism for the long-term encoding of information.

scholarly journals Cdc42 GTPase Activating Proteins (GAPs) Regulate Generational Inheritance of Cell Polarity and Cell Shape in Fission Yeast

2021 ◽  
pp. mbc.E20-10-0666
Author(s):  
Marbelys Rodriguez Pino ◽  
Illyce Nuñez ◽  
Chuan Chen ◽  
Maitreyi E. Das ◽  
David J. Wiley ◽  
...  
Keyword(s):  
Small Gtpase ◽  
Growth Patterns ◽  
Unequal Distribution ◽  
Oscillatory Dynamics ◽  
Daughter Cells ◽  
Gtpase Activating Proteins ◽  
Polarized Cell Growth ◽  
Growth Activation ◽  
Mother Cells

The highly conserved small GTPase Cdc42 regulates polarized cell growth and morphogenesis from yeast to humans. We previously reported that Cdc42 activation exhibits oscillatory dynamics at cell tips of Schizosaccharomyces pombe cells. Mathematical modeling suggests that this dynamic behavior enables a variety of symmetric and asymmetric Cdc42 activation distributions to coexist in cell populations. For individual wild type cells, however, Cdc42 distribution is initially asymmetrical and becomes more symmetrical as cell volume increases, enabling bipolar growth activation. To explore whether different patterns of Cdc42 activation are possible in vivo, we examined S. pombe rga4∆ mutant cells, lacking the Cdc42 GTPase activating protein (GAP) Rga4. We found that monopolar rga4∆ mother cells divide asymmetrically leading to the emergence of both symmetric and asymmetric Cdc42 distributions in rga4∆ daughter cells. Motivated by different hypotheses that can mathematically reproduce the unequal fate of daughter cells, we used genetic screening to identify mutants that alter the rga4∆ phenotype. We found that the unequal distribution of active Cdc42 GTPase is consistent with an unequal inheritance of another Cdc42 GAP, Rga6, in the two daughter cells. Our findings highlight the crucial role of Cdc42 GAP localization in maintaining consistent Cdc42 activation and growth patterns across generations. [Media: see text] [Media: see text] [Media: see text]

The Effect of Agents which Modify Platelet Behaviour and of Magnesium Ions on Thrombus Formation In Vivo

1979 ◽  
Vol 42 (02) ◽  
pp. 603-610 ◽  
Author(s):  
J H Adams ◽  
J R A Mitchell
Keyword(s):  
Thrombus Formation ◽  
Cerebral Arteries ◽  
Magnesium Ions ◽  
Body Formation ◽  
Inflammatory Agent ◽  
Platelet Thrombus ◽  
Magnesium Salts ◽  
Higher Doses ◽  
Do So

SummaryThe ability of potential anti-thrombotic agents to modify platelet-thrombus formation in injured cerebral arteries in the rabbit was tested. Low doses of heparin were without effect, while higher doses produced variable suppression of white body formation but at the expense of bleeding. Aspirin did not inhibit white body formation but another non-steroid anti-inflammatory agent, flurbiprofen was able to do so, as was the anti-gout agent, sulphinpyrazone. Magnesium salts both topically and parenterally, suppressed thrombus formation and increased the concentration of ADP which was required to initiate thrombus production at minor injury sites.

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