scholarly journals Checkpoint genes required to delay cell division in response to nocodazole respond to impaired kinetochore function in the yeast Saccharomyces cerevisiae.

1995 ◽  
Vol 15 (12) ◽  
pp. 6838-6844 ◽  
Author(s):  
Y Wang ◽  
D J Burke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cell Cycle Delay ◽  
Delay Cell ◽  
Antimitotic Drugs ◽  
Checkpoint Genes ◽  
Spindle Structure ◽  
Kinetochore Function

Inhibition of mitosis by antimitotic drugs is thought to occur by destruction of microtubules, causing cells to arrest through the action of one or more mitotic checkpoints. We have patterned experiments in the yeast Saccharomyces cerevisiae after recent studies in mammalian cells that demonstrate the effectiveness of antimitotic drugs at concentrations that maintain spindle structure. We show that low concentrations of nocodazole delay cell division under the control of the previously identified mitotic checkpoint genes BUB1, BUB3, MAD1, and MAD2 and independently of BUB2. The same genes mediate the cell cycle delay induced in ctf13 mutants, limited for an essential kinetochore component. Our data suggest that a low concentration of nocodazole induces a cell cycle delay through checkpoint control that is sensitive to impaired kinetochore function. The BUB2 gene may be part of a separate checkpoint that responds to abnormal spindle structure.

Cell Cycle Arrest in cdc20 Mutants of Saccharomyces cerevisiae Is Independent of Ndc10p and Kinetochore Function but Requires a Subset of Spindle Checkpoint Genes

Genetics ◽  
1998 ◽  
Vol 148 (4) ◽  
pp. 1701-1713
Author(s):  
Penny A Tavormina ◽  
Daniel J Burke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Spindle Checkpoint ◽  
Cycle Arrest ◽  
Inhibit Cell Cycle Progression ◽  
Genes Encoding ◽  
Integral Proteins ◽  
Checkpoint Genes ◽  
Kinetochore Function

Abstract The spindle checkpoint ensures accurate chromosome segregation by inhibiting anaphase onset in response to altered microtubule function and impaired kinetochore function. In this study, we report that the ability of the anti-microtubule drug nocodazole to inhibit cell cycle progression in Saccharomyces cerevisiae depends on the function of the kinetochore protein encoded by NDC10. We examined the role of the spindle checkpoint in the arrest in cdc20 mutants that arrest prior to anaphase with an aberrant spindle. The arrest in cdc20 defective cells is dependent on the BUB2 checkpoint and independent of the BUB1, BUB3, and MAD spindle checkpoint genes. We show that the lesion recognized by Bub2p is not excess microtubules, and the cdc20 arrest is independent of kinetochore function. We show that Cdc20p is not required for cyclin proteolysis at two points in the cell cycle, suggesting that CDC20 is distinct from genes encoding integral proteins of the anaphase promoting complex.

scholarly journals Telomere Cap Components Influence the Rate of Senescence in Telomerase-Deficient Yeast Cells

2004 ◽  
Vol 24 (2) ◽  
pp. 837-845 ◽  
Author(s):  
Shinichiro Enomoto ◽  
Lynn Glowczewski ◽  
Jodi Lew-Smith ◽  
Judith G. Berman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Yeast Cells ◽  
Progressive Reduction ◽  
Delayed Senescence ◽  
Cell Cycle Delay ◽  
Nonsense Mediated Mrna Decay ◽  
A Cell ◽  
Population Doublings

ABSTRACT Cells lacking telomerase undergo senescence, a progressive reduction in cell division that involves a cell cycle delay and culminates in “crisis,” a period when most cells become inviable. In telomerase-deficient Saccharomyces cerevisiae cells lacking components of the nonsense-mediated mRNA decay (NMD) pathway (Upf1,Upf2, or Upf3 proteins), senescence is delayed, with crisis occurring ∼10 to 25 population doublings later than in Upf+ cells. Delayed senescence is seen in upfΔ cells lacking the telomerase holoenzyme components Est2p and TLC1 RNA, as well as in cells lacking the telomerase regulators Est1p and Est3p. The delay of senescence in upfΔ cells is not due to an increased rate of survivor formation. Rather, it is caused by alterations in the telomere cap, composed of Cdc13p, Stn1p, and Ten1p. In upfΔ mutants, STN1 and TEN1 levels are increased. Increasing the levels of Stn1p and Ten1p in Upf+ cells is sufficient to delay senescence. In addition, cdc13-2 mutants exhibit delayed senescence rates similar to those of upfΔ cells. Thus, changes in the telomere cap structure are sufficient to affect the rate of senescence in the absence of telomerase. Furthermore, the NMD pathway affects the rate of senescence in telomerase-deficient cells by altering the stoichiometry of telomere cap components.

scholarly journals Protein synthesis requirements for nuclear division, cytokinesis, and cell separation in Saccharomyces cerevisiae.

1991 ◽  
Vol 11 (7) ◽  
pp. 3691-3698 ◽  
Author(s):  
D J Burke ◽  
D Church
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Protein Synthesis ◽  
Cell Division ◽  
Cell Separation ◽  
Nuclear Division ◽  
S Phase ◽  
Protein Synthesis Inhibitors ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chemical Inhibitors

Protein synthesis inhibitors have often been used to identify regulatory steps in cell division. We used cell division cycle mutants of the yeast Saccharomyces cerevisiae and two chemical inhibitors of translation to investigate the requirements for protein synthesis for completing landmark events after the G1 phase of the cell cycle. We show, using cdc2, cdc6, cdc7, cdc8, cdc17 (38 degrees C), and cdc21 (also named tmp1) mutants, that cells arrested in S phase complete DNA synthesis but cannot complete nuclear division if protein synthesis is inhibited. In contrast, we show, using cdc16, cdc17 (36 degrees C), cdc20, cdc23, and nocodazole treatment, that cells that arrest in the G2 stage complete nuclear division in the absence of protein synthesis. Protein synthesis is required late in the cell cycle to complete cytokinesis and cell separation. These studies show that there are requirements for protein synthesis in the cell cycle, after G1, that are restricted to two discrete intervals.

scholarly journals Roles of Hsl1p and Hsl7p in Swe1p Degradation: beyond Septin Tethering

2012 ◽  
Vol 11 (12) ◽  
pp. 1496-1502 ◽  
Author(s):  
Kindra King ◽  
Michelle Jin ◽  
Daniel Lew
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Nuclear Division ◽  
Cell Division Cycle ◽  
Cyclin Dependent Kinase ◽  
Bud Formation ◽  
Content Type ◽  
Cell Cycle Delay ◽  
Bud Neck

ABSTRACT The morphogenesis checkpoint in Saccharomyces cerevisiae couples bud formation to the cell division cycle by delaying nuclear division until cells have successfully constructed a bud. The cell cycle delay is due to the mitosis-inhibitory kinase Swe1p, which phosphorylates the cyclin-dependent kinase Cdc28p. In unperturbed cells, Swe1p is degraded via a mechanism thought to involve its tethering to a cortical scaffold of septin proteins at the mother-bud neck. In cells that experience stresses that delay bud formation, Swe1p is stabilized, accumulates, and promotes a G 2 delay. The tethering of Swe1p to the neck requires two regulators, called Hsl1p and Hsl7p. Hsl1p interacts with septins, and Hsl7p interacts with Swe1p; tethering occurs when Hsl1p interacts with Hsl7p. Here we created a version of Swe1p that is artificially tethered to the neck by fusion to a septin so that Swe1p no longer requires Hsl1p or Hsl7p for its localization to the neck. We show that the interaction between Hsl1p and Hsl7p, required for normal Swe1p degradation, is no longer needed for septin-Swe1p degradation, supporting the idea that the Hsl1p-Hsl7p interaction serves mainly to tether Swe1p to the neck. However, both Hsl1p and Hsl7p are still required for Swe1p degradation, implying that these proteins play additional roles beyond localizing Swe1p to the neck.

Protein synthesis requirements for nuclear division, cytokinesis, and cell separation in Saccharomyces cerevisiae

1991 ◽  
Vol 11 (7) ◽  
pp. 3691-3698
Author(s):  
D J Burke ◽  
D Church
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Protein Synthesis ◽  
Cell Division ◽  
Cell Separation ◽  
Nuclear Division ◽  
S Phase ◽  
Protein Synthesis Inhibitors ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chemical Inhibitors

Protein synthesis inhibitors have often been used to identify regulatory steps in cell division. We used cell division cycle mutants of the yeast Saccharomyces cerevisiae and two chemical inhibitors of translation to investigate the requirements for protein synthesis for completing landmark events after the G1 phase of the cell cycle. We show, using cdc2, cdc6, cdc7, cdc8, cdc17 (38 degrees C), and cdc21 (also named tmp1) mutants, that cells arrested in S phase complete DNA synthesis but cannot complete nuclear division if protein synthesis is inhibited. In contrast, we show, using cdc16, cdc17 (36 degrees C), cdc20, cdc23, and nocodazole treatment, that cells that arrest in the G2 stage complete nuclear division in the absence of protein synthesis. Protein synthesis is required late in the cell cycle to complete cytokinesis and cell separation. These studies show that there are requirements for protein synthesis in the cell cycle, after G1, that are restricted to two discrete intervals.

scholarly journals Recombination of Ty elements in yeast can be induced by a double-strand break.

Genetics ◽  
1995 ◽  
Vol 140 (1) ◽  
pp. 67-77 ◽  
Author(s):  
A Parket ◽  
O Inbar ◽  
M Kupiec
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Strand Break ◽  
Double Strand Break ◽  
The Other ◽  
Direct Repeats ◽  
Yeast Saccharomyces Cerevisiae ◽  
Low Frequencies ◽  
Ty Elements ◽  
Main Family

Abstract The Ty retrotransposons are the main family of dispersed repeated sequences in the yeast Saccharomyces cerevisiae. These elements are flanked by a pair of long terminal direct repeats (LTRs). Previous experiments have shown that Ty elements recombine at low frequencies, despite the fact that they are present in 30 copies per genome. This frequency is not highly increased by treatments that cause DNA damage, such as UV irradiation. In this study, we show that it is possible to increase the recombination level of a genetically marked Ty by creating a double-strand break in it. This break is repaired by two competing mechanisms: one of them leaves a single LTR in place of the Ty, and the other is a gene conversion event in which the marked Ty is replaced by an ectopically located one. In a strain in which the marked Ty has only one LTR, the double-strand break is repaired by conversion. We have also measured the efficiency of repair and monitored the progression of the cells through the cell-cycle. We found that in the presence of a double-strand break in the marked Ty, a proportion of the cells is unable to resume growth.

scholarly journals The Spindle Checkpoint of the Yeast Saccharomyces cerevisiae Requires Kinetochore Function and Maps to the CBF3 Domain

Genetics ◽  
2001 ◽  
Vol 157 (4) ◽  
pp. 1493-1502
Author(s):  
Richard D Gardner ◽  
Atasi Poddar ◽  
Chris Yellman ◽  
Penny A Tavormina ◽  
M Cristina Monteagudo ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Critical Role ◽  
Spindle Checkpoint ◽  
Essential Genes ◽  
Gene Fusions ◽  
Yeast Saccharomyces Cerevisiae ◽  
Checkpoint Signaling ◽  
One Step ◽  
Diploid Cells ◽  
Kinetochore Function

Abstract We have measured the activity of the spindle checkpoint in null mutants lacking kinetochore activity in the yeast Saccharomyces cerevisiae. We constructed deletion mutants for nonessential genes by one-step gene replacements. We constructed heterozygous deletions of one copy of essential genes in diploid cells and purified spores containing the deletion allele. In addition, we made gene fusions for three essential genes to target the encoded proteins for proteolysis (degron alleles). We determined that Ndc10p, Ctf13p, and Cep3p are required for checkpoint activity. In contrast, cells lacking Cbf1p, Ctf19p, Mcm21p, Slk19p, Cse4p, Mif2p, Mck1p, and Kar3p are checkpoint proficient. We conclude that the kinetochore plays a critical role in checkpoint signaling in S. cerevisiae. Spindle checkpoint activity maps to a discreet domain within the kinetochore and depends on the CBF3 protein complex.

Histone H3 transcription in Saccharomyces cerevisiae is controlled by multiple cell cycle activation sites and a constitutive negative regulatory element

1992 ◽  
Vol 12 (12) ◽  
pp. 5455-5463 ◽  
Author(s):  
K B Freeman ◽  
L R Karns ◽  
K A Lutz ◽  
M M Smith
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Transcriptional Activation ◽  
Regulatory Element ◽  
Histone H3 ◽  
Regulatory Elements ◽  
Cell Division Cycle ◽  
Cell Cycle Activation ◽  
Multiple Cell

The promoters of the Saccharomyces cerevisiae histone H3 and H4 genes were examined for cis-acting DNA sequence elements regulating transcription and cell division cycle control. Deletion and linker disruption mutations identified two classes of regulatory elements: multiple cell cycle activation (CCA) sites and a negative regulatory site (NRS). Duplicate 19-bp CCA sites are present in both the copy I and copy II histone H3-H4 promoters arranged as inverted repeats separated by 45 and 68 bp. The CCA sites are both necessary and sufficient to activate transcription under cell division cycle control. A single CCA site provides cell cycle control but is a weak transcriptional activator, while an inverted repeat comprising two CCA sites provides both strong transcriptional activation and cell division cycle control. The NRS was identified in the copy I histone H3-H4 promoter. Deletion or disruption of the NRS increased the level of the histone H3 promoter activity but did not alter the cell division cycle periodicity of transcription. When the CCA sites were deleted from the histone promoter, the NRS element was unable to confer cell division cycle control on the remaining basal level of transcription. When the NRS element was inserted into the promoter of a foreign reporter gene, transcription was constitutively repressed and did not acquire cell cycle regulation.

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