scholarly journals Existence, Transition, and Propagation of Intermediate Silencing States in Ribosomal DNA

2019 ◽  
Vol 39 (23) ◽  
Author(s):  
Fan Zou ◽  
Manyu Du ◽  
Hengye Chen ◽  
Lu Bai
Keyword(s):  
Cell Cycle ◽  
Ribosomal Dna ◽  
Time Lapse ◽  
Dynamic Activity ◽  
Gene Expression Noise ◽  
Daughter Cells ◽  
Mother And Daughter ◽  
Cell Cycle Dependence ◽  
Highly Correlated ◽  
Cycle Dependence

ABSTRACT The MET3 promoter (MET3pr) inserted into the silenced chromosome in budding yeast can overcome Sir2-dependent silencing upon induction and activate transcription in every single cell among a population. Despite the fact that MET3pr is turned on in all the cells, its activity still shows very high cell-to-cell variability. To understand the nature of such “gene expression noise,” we followed the dynamics of the MET3pr-GFP expression inserted into ribosomal DNA (rDNA) using time-lapse microscopy. We found that the noisy “on” state is comprised of multiple substable states with discrete expression levels. These intermediate states stochastically transition between each other, with “up” transitions among different activated states occurring exclusively near the mitotic exit and “down” transitions occurring throughout the rest of the cell cycle. Such cell cycle dependence likely reflects the dynamic activity of the rDNA-specific RENT complex, as MET3pr-GFP expression in a telomeric locus does not have the same cell cycle dependence. The MET3pr-GFP expression in rDNA is highly correlated in mother and daughter cells after cell division, indicating that the silenced state in the mother cell is inherited in daughter cells. These states are disrupted by a brief repression and reset upon a second activation. Potential mechanisms behind these observations are further discussed.

scholarly journals A novel inward-rectifying K+ current with a cell-cycle dependence governs the resting potential of mammalian neuroblastoma cells.

1995 ◽  
Vol 489 (2) ◽  
pp. 455-471 ◽  
Author(s):  
A Arcangeli ◽  
L Bianchi ◽  
A Becchetti ◽  
L Faravelli ◽  
M Coronnello ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Neuroblastoma Cells ◽  
Resting Potential ◽  
K Current ◽  
A Cell ◽  
Cell Cycle Dependence ◽  
Cycle Dependence

The Cell Cycle Dependence of Thermotolerance: II. CHO Cells Heated at 45.0°C

1984 ◽  
Vol 98 (3) ◽  
pp. 491 ◽  
Author(s):  
R. A. Read ◽  
M. H. Fox ◽  
J. S. Bedford
Keyword(s):  
Cell Cycle ◽  
Cho Cells ◽  
Cell Cycle Dependence ◽  
Cycle Dependence

scholarly journals Cell Cycle-Dependence of Autophagic Activity and Inhibition of Autophagosome Formation at M Phase in Tobacco BY-2 Cells

2020 ◽  
Vol 21 (23) ◽  
pp. 9166
Author(s):  
Shigeru Hanamata ◽  
Takamitsu Kurusu ◽  
Kazuyuki Kuchitsu
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Plant Cells ◽  
Regulatory Mechanisms ◽  
Cdk Inhibitor ◽  
Autophagosome Formation ◽  
Cycle Progression ◽  
M Phase ◽  
Cell Cycle Dependence ◽  
Cycle Dependence

Autophagy is ubiquitous in eukaryotic cells and plays an essential role in stress adaptation and development by recycling nutrients and maintaining cellular homeostasis. However, the dynamics and regulatory mechanisms of autophagosome formation during the cell cycle in plant cells remain poorly elucidated. We here analyzed the number of autophagosomes during cell cycle progression in synchronized tobacco BY-2 cells expressing YFP-NtATG8a as a marker for the autophagosomes. Autophagosomes were abundant in the G2 and G1 phases of interphase, though they were much less abundant in the M and S phases. Autophagosomes drastically decreased during the G2/M transition, and the CDK inhibitor roscovitine inhibited the G2/M transition and the decrease in autophagosomes. Autophagosomes were rapidly increased by a proteasome inhibitor, MG-132. MG-132-induced autophagosome formation was also markedly lower in the M phases than during interphase. These results indicate that the activity of autophagosome formation is differently regulated at each cell cycle stage, which is strongly suppressed during mitosis.

scholarly journals Cell Cycle Dependence of Group VIA Calcium-independent Phospholipase A2Activity

2004 ◽  
Vol 279 (51) ◽  
pp. 52881-52892 ◽  
Author(s):  
Alex D. Manguikian ◽  
Suzanne E. Barbour
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Dependence ◽  
Cycle Dependence

scholarly journals Cell cycle phases in the unequal mother/daughter cell cycles of Saccharomyces cerevisiae.

1984 ◽  
Vol 4 (11) ◽  
pp. 2529-2531 ◽  
Author(s):  
B J Brewer ◽  
E Chlebowicz-Sledziewska ◽  
W L Fangman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cycle Phase ◽  
Cell Cycle Time ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cell Cycles ◽  
Daughter Cells ◽  
Mother And Daughter ◽  
Cell Cycle Phases ◽  
Mother Cells

During cell division in the yeast Saccharomyces cerevisiae mother cells produce buds (daughter cells) which are smaller and have longer cell cycles. We performed experiments to compare the lengths of cell cycle phases in mothers and daughters. As anticipated from earlier indirect observations, the longer cell cycle time of daughter cells is accounted for by a longer G1 interval. The S-phase and the G2-phase are of the same duration in mother and daughter cells. An analysis of five isogenic strains shows that cell cycle phase lengths are independent of cell ploidy and mating type.

scholarly journals Spindle-independent condensation-mediated segregation of yeast ribosomal DNA in late anaphase

2005 ◽  
Vol 168 (2) ◽  
pp. 209-219 ◽  
Author(s):  
Félix Machín ◽  
Jordi Torres-Rosell ◽  
Adam Jarmuz ◽  
Luis Aragón
Keyword(s):  
Cell Division ◽  
Ribosomal Dna ◽  
Budding Yeast ◽  
Mitotic Cell ◽  
Yeast Genome ◽  
Daughter Cells ◽  
Late Anaphase ◽  
Mother And Daughter ◽  
The Right ◽  
Chromosome Resolution

Mitotic cell division involves the equal segregation of all chromosomes during anaphase. The presence of ribosomal DNA (rDNA) repeats on the right arm of chromosome XII makes it the longest in the budding yeast genome. Previously, we identified a stage during yeast anaphase when rDNA is stretched across the mother and daughter cells. Here, we show that resolution of sister rDNAs is achieved by unzipping of the locus from its centromere-proximal to centromere-distal regions. We then demonstrate that during this stretched stage sister rDNA arrays are neither compacted nor segregated despite being largely resolved from each other. Surprisingly, we find that rDNA segregation after this period no longer requires spindles but instead involves Cdc14-dependent rDNA axial compaction. These results demonstrate that chromosome resolution is not simply a consequence of compacting chromosome arms and that overall rDNA compaction is necessary to mediate the segregation of the long arm of chromosome XII.

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