Conservation of the Centromere/Kinetochore Protein ZW10

Mutations in the essential Drosophila melanogaster gene zw10 disrupt chromosome segregation, producing chromosomes that lag at the metaphase plate during anaphase of mitosis and both meiotic divisions. Recent evidence suggests that the product of this gene, DmZW10, acts at the kinetochore as part of a tension-sensing checkpoint at anaphase onset. DmZW10 displays an intriguing cell cycle–dependent intracellular distribution, apparently moving from the centromere/kinetochore at prometaphase to kinetochore microtubules at metaphase, and back to the centromere/kinetochore at anaphase (Williams, B.C., M. Gatti, and M.L. Goldberg. 1996. J. Cell Biol. 134:1127-1140). We have identified ZW10-related proteins from widely diverse species with divergent centromere structures, including several Drosophilids, Caenorhabditis elegans, Arabidopsis thaliana, Mus musculus, and humans. Antibodies against the human ZW10 protein display a cell cycle–dependent staining pattern in HeLa cells strikingly similar to that previously observed for DmZW10 in dividing Drosophila cells. Injections of C. elegans ZW10 antisense RNA phenocopies important aspects of the mutant phenotype in Drosophila: these include a strong decrease in brood size, suggesting defects in meiosis or germline mitosis, a high percentage of lethality among the embryos that are produced, and the appearance of chromatin bridges at anaphase. These results indicate that at least some aspects of the functional role of the ZW10 protein in ensuring proper chromosome segregation are conserved across large evolutionary distances.

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Distinct Developmental Function of Two Caenorhabditis elegans Homologs of the Cohesin Subunit Scc1/Rad21

Molecular Biology of the Cell ◽

10.1091/mbc.e02-09-0603 ◽

2003 ◽

Vol 14 (6) ◽

pp. 2399-2409 ◽

Cited By ~ 21

Author(s):

Yoshiko Mito ◽

Asako Sugimoto ◽

Masayuki Yamamoto

Keyword(s):

Cell Cycle ◽

Caenorhabditis Elegans ◽

Chromosome Segregation ◽

Mitotic Chromosome ◽

Dependent Manner ◽

C Elegans ◽

Late Embryogenesis ◽

A Cell ◽

Cohesin Subunit ◽

Cycle Dependent

Cohesin, which mediates sister chromatid cohesion, is composed of four subunits, named Scc1/Rad21, Scc3, Smc1, and Smc3 in yeast. Caenorhabditis elegans has a single homolog for each of Scc3, Smc1, and Smc3, but as many as four for Scc1/Rad21 (COH-1, SCC-1/COH-2, COH-3, and REC-8). Except for REC-8 required for meiosis, function of these C. elegans proteins remains largely unknown. Herein, we examined their possible involvement in mitosis and development. Embryos depleted of the homolog of either Scc3, or Smc1, or Smc3 by RNA interference revealed a defect in mitotic chromosome segregation but not in chromosome condensation and cytokinesis. Depletion of SCC-1/COH-2 caused similar phenotypes. SCC-1/COH-2 was present in cells destined to divide. It localized to chromosomes in a cell cycle-dependent manner. Worms depleted of COH-1 arrested at either the late embryonic or the larval stage, with no indication of mitotic dysfunction. COH-1 associated chromosomes throughout the cell cycle in all somatic cells undergoing late embryogenesis or larval development. Thus, SCC-1/COH-2 and the homologs of Scc3, Smc1, and Smc3 facilitate mitotic chromosome segregation during the development, presumably by forming a cohesin complex, whereas COH-1 seems to play a role important for development but unrelated to mitosis.

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A direct measurement of increased divalent cation influx in fertilised mouse oocytes

Development ◽

10.1242/dev.122.7.2199 ◽

1996 ◽

Vol 122 (7) ◽

pp. 2199-2206 ◽

Cited By ~ 5

Author(s):

O.M. McGuinness ◽

R.B. Moreton ◽

M.H. Johnson ◽

M.J. Berridge

Keyword(s):

Cell Cycle ◽

Dependent Manner ◽

Continuous Increase ◽

Mouse Oocytes ◽

A Cell ◽

Cycle Dependent ◽

Precise Role ◽

Entry Mechanism ◽

Stimulation Of

On fertilisation of mouse oocytes, the fusing spermatozoon triggers a series of repetitive calcium (Ca2+) spikes. The Ca2+ spikes seem to be necessary for successful progression through the cell cycle and are regulated in a cell-cycle-dependent manner. The spikes appear to require the linkage of continuous Ca2+ influx to the periodic release of Ca2+ from intracellular stores by a process of Ca(2+)-induced Ca2+ release. The precise role of Ca2+ influx was explored using the manganese (Mn2+)-quench technique to monitor unidirectional cation influx into single mouse oocytes. There was a marked stimulation of cation influx associated closely with the upsweep of the first and subsequent fertilisation Ca2+ spikes. A smaller but significant increase in the rate of cation influx persisted in the interspike period in fertilised oocytes. Spike-associated entry was not as apparent in oocytes stimulated to spike repetitively by thimerosal or acetylcholine application. Instead, there was a continuous increase in cation influx underlying Ca2+ spiking which commenced with the onset of the first spike. Using the specific microsomal inhibitor thapsigargin and the Ca2+ ionophore ionomycin, we found evidence for a capacitative entry mechanism in mouse oocytes. We propose that the persistent influx of Ca2+ observed in response to all stimuli examined is controlled by a capacitative mechanism and sets the frequency of spiking by determining the time taken to refill the internal stores to a point where they are again sensitive enough to initiate the next spike.

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A Role for NIPA in DNA Damage Response.

Blood ◽

10.1182/blood.v104.11.1265.1265 ◽

2004 ◽

Vol 104 (11) ◽

pp. 1265-1265

Author(s):

Christine von Klitzing ◽

Florian Bassermann ◽

Stephan W. Morris ◽

Christian Peschel ◽

Justus Duyster

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Dna Damage Response ◽

Phosphorylation Site ◽

Genotoxic Stress ◽

S Phase ◽

Damage Response ◽

A Cell ◽

Cycle Dependent

Abstract The nuclear interaction partner of ALK (NIPA) is a nuclear protein identified by our group in a screen for NPM-ALK interaction partners. We recently reported that NIPA is an F-box protein that assembles with SKP1, Cul1 and Roc1 to establish a novel SCF-type E3 ubiquitin ligase. The formation of the SCFNIPA complex is regulated by cell cycle-dependent phosphorylation of NIPA that restricts SCFNIPA assembly from G1- to late S-phase, thus allowing its substrates to be active from late S-phase throughout mitosis. Proteins involved in cell cycle regulation frequently play a role in DNA damage checkpoints. We therefore sought to determine whether NIPA has a function in the cellular response to genotoxic stress. For this reason we treated NIH/3T3 cells with various DNA-damaging agents. Surprisingly, we observed phosphorylation of NIPA in response to some of these agents, including UV radiation. This phosphorylation was cell cycle phase independent and thus independent of the physiological cell cycle dependent phosphorylation of NIPA. The relevant phosphorylation site is identical to the respective site in the course of cell cycle-dependent phosphorylation of NIPA. Thus, phosphorylation of NIPA upon genotoxic stress would inactivate the SCFNIPA complex in a cell cycle independent manner. Interestingly, this phosphorylation site lies within a consensus site of the Chk1/Chk2 checkpoint kinases. These kinases are central to DNA damage checkpoint signaling. Chk1 is activated by ATR in response to blocked replication forks as they occur after treatment with UV. We performed experiments using the ATM/ATR inhibitor caffeine and the Chk1 inhibitor SB218078 to investigate a potential role of Chk1 in NIPA phosphorylation. Indeed, we found both inhibitors to prevent UV-induced phosphorylation of NIPA. Current experiments applying Chk1 knock-out cells will unravel the role of Chk1 in NIPA phosphorylation. Additional experiments were performed to investigate a function for NIPA in DNA-damage induced apoptosis. In this regard, we observed overexpression of NIPA WT to induce apoptosis in response to UV, whereas no proapoptotic effect was seen with the phosphorylation deficient NIPA mutant. Therefore, the phosphorylated form of NIPA may be involved in apoptotic signaling pathways. In summary, we present data suggesting a cell cycle independent function for NIPA. This activity is involved in DNA damage response and may be involved in regulating apoptosis upon genotoxic stress.

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Dynamic cell cycle-dependent phosphorylation modulates CENP-L-CENP-N centromere recruitment

10.1101/2021.12.17.473210 ◽

2021 ◽

Author(s):

Alexandra P Navarro ◽

Iain M Cheeseman

Keyword(s):

Cell Cycle ◽

Chromosome Segregation ◽

S Phase ◽

Dependent Manner ◽

Dynamic Cell ◽

A Cell ◽

Cycle Dependent ◽

Unique Cell ◽

Localization Behavior ◽

Constitutive Phosphorylation

The kinetochore is a macromolecular structure that is required to ensure proper chromosome segregation during each cell division. The kinetochore is assembled upon a platform of the 16-subunit Constitutive Centromere Associated Network (CCAN), which is present at centromeres throughout the cell cycle. The nature and regulation of CCAN assembly, interactions, and dynamics required to facilitate changing centromere properties and requirements remain to be fully elucidated. The CENP-LN CCAN sub-complex displays a unique cell cycle-dependent localization behavior, peaking in S phase. Here, we demonstrate that phosphorylation of CENP-L and CENP-N controls CENP-LN complex formation and localization in a cell cycle-dependent manner. Mimicking constitutive phosphorylation of either CENP-L or CENP-N or simultaneously preventing phosphorylation of both proteins prevents CENP-LN localization and disrupts chromosome segregation. Together, our work suggests that cycles of phosphorylation and dephosphorylation are critical for CENP-LN complex recruitment and dynamics at centromeres to enable cell cycle-dependent CCAN reorganization.

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Cell cycle S-phase arrest drives cell extrusion

10.1101/839845 ◽

2019 ◽

Cited By ~ 1

Author(s):

Vivek K. Dwivedi ◽

Carlos Pardo-Pastor ◽

Rita Droste ◽

Daniel P. Denning ◽

Jody Rosenblatt ◽

...

Keyword(s):

Cell Cycle ◽

S Phase ◽

C Elegans ◽

Phase Arrest ◽

Genome Wide ◽

S Phase Arrest ◽

Epithelial Cultures ◽

A Cell ◽

Cycle Dependent ◽

Cell Extrusion

SUMMARYCell extrusion is a process of cell elimination in which a cell is squeezed out from its tissue of origin. Extrusion occurs in organisms as diverse as sponges, nematodes, insects, fish and mammals. Defective extrusion is linked to many epithelial disorders, including cancer. Despite broad occurrence, cell-intrinsic triggers of extrusion conserved across phyla are generally unknown. We combined genome-wide genetic screens with live-imaging studies of C. elegans embryos and mammalian epithelial cultures and found that S-phase arrest induced extrusion in both. Cells extruded from C. elegans embryos exhibited S-phase arrest, and RNAi treatments that specifically prevent S-phase entry or arrest blocked cell extrusion. Pharmacological induction of S-phase arrest was sufficient to promote cell extrusion from a canine epithelial monolayer. Thus, we have discovered an evolutionarily conserved cell-cycle-dependent trigger of cell extrusion. We suggest that S-phase-arrest induced cell extrusion plays a key role in physiology and disease.

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Faculty Opinions recommendation of A cell cycle-dependent regulatory circuit composed of 53BP1-RIF1 and BRCA1-CtIP controls DNA repair pathway choice.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717972354.793478994 ◽

2013 ◽

Author(s):

Carol MacKintosh

Keyword(s):

Cell Cycle ◽

Dna Repair ◽

Repair Pathway ◽

Regulatory Circuit ◽

A Cell ◽

Pathway Choice ◽

Cycle Dependent

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Deregulation of cell cycle and related microRNA expression induced by vinyl chloride monomer in hepatocytes of rats

Toxicology and Industrial Health ◽

10.1177/07482337211015591 ◽

2021 ◽

pp. 074823372110155

Author(s):

Weizhe Pan ◽

Shengnan Yu ◽

Jin Jia ◽

Junyang Hu ◽

Liang Jie ◽

...

Keyword(s):

Cell Cycle ◽

Vinyl Chloride ◽

Male Rats ◽

Cell Cycle Distribution ◽

Vinyl Chloride Monomer ◽

Dynamic Changes ◽

Cell Cycle Deregulation ◽

Change Dynamic ◽

Related Proteins

Vinyl chloride (VC) is a confirmed human carcinogen associated with hepatocellular carcinoma and angiosarcoma. However, the role of microRNAs (miRNAs) in liver cell cycle changes under VC exposure remains unclear, which prevents research on the mechanism of VC-induced carcinogenesis. In this study, male rats were injected intraperitoneally with VC (0, 5, 25, and 125 mg/kg body weight) for 6, 8, and 12 weeks. Cell cycle analysis of liver cells, miRNA-222, miRNA-199a, miRNA-195, and miRNA-125b expression in the liver and serum, and target protein expression were performed at different time points. The results showed a higher percentage of hepatocytes in the G1/G0 and S phases at the end of 6 and 12 weeks of VC exposure, respectively. MiRNA-222 expression decreased initially and then increased, whereas miRNA-199a, miRNA-195, and miRNA-125b expression increased initially and then decreased, which corresponded with changes in cell cycle distribution and related target proteins expression (p27, cyclinA, cyclinD1, and CDK6). The corresponding expression levels of miRNAs in serum did not change. Dynamic changes in miR-222, miR-199a, miR-195, and miR-125b induced by VC can lead to cell cycle deregulation by affecting cell cycle-related proteins, and these miRNAs can serve as early biomarkers for malignant transformation caused by VC.

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The Role of Cdh1p in Maintaining Genomic Stability in Budding Yeast

Genetics ◽

10.1093/genetics/165.2.489 ◽

2003 ◽

Vol 165 (2) ◽

pp. 489-503 ◽

Cited By ~ 1

Author(s):

Karen E Ross ◽

Orna Cohen-Fix

Keyword(s):

Cell Cycle ◽

Chromosome Segregation ◽

Spindle Assembly Checkpoint ◽

Chromosome Loss ◽

Cyclin Dependent Kinase ◽

Anaphase Promoting Complex ◽

Growth Defects ◽

Genes Encoding ◽

Specificity Factor

Abstract Cdh1p, a substrate specificity factor for the cell cycle-regulated ubiquitin ligase, the anaphase-promoting complex/cyclosome (APC/C), promotes exit from mitosis by directing the degradation of a number of proteins, including the mitotic cyclins. Here we present evidence that Cdh1p activity at the M/G1 transition is important not only for mitotic exit but also for high-fidelity chromosome segregation in the subsequent cell cycle. CDH1 showed genetic interactions with MAD2 and PDS1, genes encoding components of the mitotic spindle assembly checkpoint that acts at metaphase to prevent premature chromosome segregation. Unlike cdh1Δ and mad2Δ single mutants, the mad2Δ cdh1Δ double mutant grew slowly and exhibited high rates of chromosome and plasmid loss. Simultaneous deletion of PDS1 and CDH1 caused extensive chromosome missegregation and cell death. Our data suggest that at least part of the chromosome loss can be attributed to kinetochore/spindle problems. Our data further suggest that Cdh1p and Sic1p, a Cdc28p/Clb inhibitor, have overlapping as well as nonoverlapping roles in ensuring proper chromosome segregation. The severe growth defects of both mad2Δ cdh1Δ and pds1Δ cdh1Δ strains were rescued by overexpressing Swe1p, a G2/M inhibitor of the cyclin-dependent kinase, Cdc28p/Clb. We propose that the failure to degrade cyclins at the end of mitosis leaves cdh1Δ mutant strains with abnormal Cdc28p/Clb activity that interferes with proper chromosome segregation.

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