Dual Cell Cycle Checkpoints Sensitive to Chromosome Replication and DNA Damage in the Budding Yeast Saccharomyces cerevisiae

1992 ◽  
Vol 132 (2) ◽  
pp. 141 ◽  
Author(s):  
Ted A. Weinert
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Damage ◽  
Budding Yeast ◽  
Chromosome Replication ◽  
Cell Cycle Checkpoints ◽  
Yeast Saccharomyces Cerevisiae

scholarly journals Microtubule Dynamics from Mating through the First Zygotic Division in the Budding Yeast Saccharomyces cerevisiae

1999 ◽  
Vol 144 (5) ◽  
pp. 977-987 ◽  
Author(s):  
Paul Maddox ◽  
E. Chin ◽  
A. Mallavarapu ◽  
E. Yeh ◽  
E.D. Salmon ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Fusion ◽  
Fluorescent Protein ◽  
Budding Yeast ◽  
Time Lapse ◽  
Spindle Pole ◽  
Microtubule Dynamics ◽  
Cell Cycle Checkpoints ◽  
Yeast Saccharomyces Cerevisiae

We have used time-lapse digital imaging microscopy to examine cytoplasmic astral microtubules (Mts) and spindle dynamics during the mating pathway in budding yeast Saccharomyces cerevisiae. Mating begins when two cells of opposite mating type come into proximity. The cells arrest in the G1 phase of the cell cycle and grow a projection towards one another forming a shmoo projection. Imaging of microtubule dynamics with green fluorescent protein (GFP) fusions to dynein or tubulin revealed that the nucleus and spindle pole body (SPB) became oriented and tethered to the shmoo tip by a Mt-dependent search and capture mechanism. Dynamically unstable astral Mts were captured at the shmoo tip forming a bundle of three or four astral Mts. This bundle changed length as the tethered nucleus and SPB oscillated toward and away from the shmoo tip at growth and shortening velocities typical of free plus end astral Mts (∼0.5 μm/min). Fluorescent fiduciary marks in Mt bundles showed that Mt growth and shortening occurred primarily at the shmoo tip, not the SPB. This indicates that Mt plus end assembly/disassembly was coupled to pushing and pulling of the nucleus. Upon cell fusion, a fluorescent bar of Mts was formed between the two shmoo tip bundles, which slowly shortened (0.23 ± 0.07 μm/min) as the two nuclei and their SPBs came together and fused (karyogamy). Bud emergence occurred adjacent to the fused SPB ∼30 min after SPB fusion. During the first mitosis, the SPBs separated as the spindle elongated at a constant velocity (0.75 μm/min) into the zygotic bud. There was no indication of a temporal delay at the 2-μm stage of spindle morphogenesis or a lag in Mt nucleation by replicated SPBs as occurs in vegetative mitosis implying a lack of normal checkpoints. Thus, the shmoo tip appears to be a new model system for studying Mt plus end dynamic attachments and much like higher eukaryotes, the first mitosis after haploid cell fusion in budding yeast may forgo cell cycle checkpoints present in vegetative mitosis.

Localization of a 210-kDa microtubule-interacting protein in the yeast Saccharomyces cerevisiae

1992 ◽  
Vol 38 (2) ◽  
pp. 149-152 ◽  
Author(s):  
J. Hašek ◽  
J. Jochová ◽  
P. Dráber ◽  
V. Viklický ◽  
E. Streiblová
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Monoclonal Antibody ◽  
Plasma Membrane ◽  
Key Words ◽  
Budding Yeast ◽  
Yeast Saccharomyces Cerevisiae ◽  
Double Labeling ◽  
Interacting Protein ◽  
Cytoplasmic Microtubules

Using the monoclonal antibody MA-01, which recognizes a 210-kDa protein in cell-free extracts, spindle and cytoplasmic microtubules were visualized in budding yeast, Saccharomyces cerevisiae. In additional, a spot-like staining was found beneath the plasma membrane, revealing in part correlation with F-actin distribution. This pattern was common for cells of all cell-cycle stages. The interaction of the protein recognized by MA-01 with microtubules was confirmed in the double labeling with a polyclonal antitubulin antibody and by the sensitivity of intranuclear structures stained by MA-01 to the microtubule disrupting drug nocodazole. Key words: immunoblotting, immunofluorescence, microtubule-interacting protein, Saccharomyces cerevisiae.

scholarly journals Using Budding Yeast to Identify Molecules That Block Cancer Cell ‘Mitotic Slippage’ Only in the Presence of Mitotic Poisons

2021 ◽  
Vol 22 (15) ◽  
pp. 7985
Author(s):  
Scott C. Schuyler ◽  
Hsin-Yu Chen
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Drug Targets ◽  
Budding Yeast ◽  
Eukaryotic Cell ◽  
Mitotic Checkpoint ◽  
Chemotherapeutic Agents ◽  
Cell Cycle Checkpoints ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mitotic Slippage

Research on the budding yeast Saccharomyces cerevisiae has yielded fundamental discoveries on highly conserved biological pathways and yeast remains the best-studied eukaryotic cell in the world. Studies on the mitotic cell cycle and the discovery of cell cycle checkpoints in budding yeast has led to a detailed, although incomplete, understanding of eukaryotic cell cycle progression. In multicellular eukaryotic organisms, uncontrolled aberrant cell division is the defining feature of cancer. Some of the most successful classes of anti-cancer chemotherapeutic agents are mitotic poisons. Mitotic poisons are thought to function by inducing a mitotic spindle checkpoint-dependent cell cycle arrest, via the assembly of the highly conserved mitotic checkpoint complex (MCC), leading to apoptosis. Even in the presence of mitotic poisons, some cancer cells continue cell division via ‘mitotic slippage’, which may correlate with a cancer becoming refractory to mitotic poison chemotherapeutic treatments. In this review, knowledge about budding yeast cell cycle control is explored to suggest novel potential drug targets, namely, specific regions in the highly conserved anaphase-promoting complex/cyclosome (APC/C) subunits Apc1 and/or Apc5, and in a specific N-terminal region in the APC/C co-factor cell division cycle 20 (Cdc20), which may yield molecules which block ‘mitotic slippage’ only in the presence of mitotic poisons.

scholarly journals IBD2 Encodes a Novel Component of the Bub2p-Dependent Spindle Checkpoint in the Budding Yeast Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 161 (2) ◽  
pp. 595-609
Author(s):  
Hyung-Seo Hwang ◽  
Kiwon Song
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Budding Yeast ◽  
Essential Gene ◽  
Spindle Checkpoint ◽  
Mitotic Arrest ◽  
Mitotic Exit ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Checkpoint Pathway

Abstract During mitosis, genomic integrity is maintained by the proper coordination of mitotic events through the spindle checkpoint. The bifurcated spindle checkpoint blocks cell cycle progression at metaphase by monitoring unattached kinetochores and inhibits mitotic exit in response to the incorrect orientation of the mitotic spindle. Bfa1p is a spindle checkpoint regulator of budding yeast in the Bub2p checkpoint pathway for proper mitotic exit. We have isolated a novel Bfa1p interacting protein named Ibd2p in the budding yeast Saccharomyces cerevisiae. We found that IBD2 (Inhibition of Bud Division 2) is not an essential gene but its deletion mutant proceeded through the cell cycle in the presence of microtubule-destabilizing drugs, thereby inducing a sharp decrease in viability. In addition, overexpression of Mps1p caused partial mitotic arrest in ibd2Δ as well as in bub2Δ, suggesting that IBD2 encodes a novel component of the spindle checkpoint downstream of MPS1. Overexpression of Ibd2p induced mitotic arrest with increased levels of Clb2p in wild type and mad2Δ, but not in deletion mutants of BUB2 and BFA1. Pds1p was also stabilized by the overexpression of Ibd2p in wild-type cells. The mitotic arrest defects observed in ibd2Δ in the presence of nocodazole were restored by additional copies of BUB2, BFA1, and CDC5, whereas an extra copy of IBD2 could not rescue the mitotic arrest defects of bub2Δ and bfa1Δ. The mitotic arrest defects of ibd2Δ were not recovered by MAD2, or vice versa. Analysis of the double mutant combinations ibd2Δmad2Δ, ibd2Δbub2Δ, and ibd2Δdyn1Δ showed that IBD2 belongs to the BUB2 epistasis group. Taken together, these data demonstrate that IBD2 encodes a novel component of the BUB2-dependent spindle checkpoint pathway that functions upstream of BUB2 and BFA1.

scholarly journals A novel role for Cdc5p in DNA replication.

1996 ◽  
Vol 16 (12) ◽  
pp. 6775-6782 ◽  
Author(s):  
C F Hardy ◽  
A Pautz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Replication ◽  
Origin Recognition Complex ◽  
Budding Yeast ◽  
Yeast Saccharomyces Cerevisiae ◽  
Plasmid Maintenance ◽  
Multiple Origins ◽  
Synthetically Lethal ◽  
Origin Recognition

DNA replication initiates from specific chromosomal sites called origins, and in the budding yeast Saccharomyces cerevisiae these sites are occupied by the origin recognition complex (ORC). Dbf4p is proposed to play a role in targeting the G1/S kinase Cdc7p to initiation complexes late in G1. We report that Dbf4p may also recruit Cdc5p to origin complexes. Cdc5p is a member of the Polo family of kinases that is required for the completion of mitosis. Cdc5p and Cdc7p each interact with a distinct domain of Dbf4p. cdc5-1 mutants have a plasmid maintenance defect that can be suppressed by the addition of multiple origins. cdc5-1 orc2-1 double mutants are synthetically lethal. Levels of Cdc5p were found to be cell cycle regulated and peaked in G2/M. These results suggest a role for Cdc5p and possibly Polo-like kinases at origin complexes.

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