scholarly journals The budding yeast Ipl1/Aurora protein kinase regulates mitotic spindle disassembly

2003 ◽  
Vol 160 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Stéphanie Buvelot ◽  
Sean Y. Tatsutani ◽  
Danielle Vermaak ◽  
Sue Biggins
Keyword(s):  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Kinase Activity ◽  
Budding Yeast ◽  
Genomic Stability ◽  
Time Lapse ◽  
Time Lapse Microscopy ◽  
Spindle Disassembly ◽  
Spindle Midzone ◽  
Spindle Microtubules

Ipl1p is the budding yeast member of the Aurora family of protein kinases, critical regulators of genomic stability that are required for chromosome segregation, the spindle checkpoint, and cytokinesis. Using time-lapse microscopy, we found that Ipl1p also has a function in mitotic spindle disassembly that is separable from its previously identified roles. Ipl1–GFP localizes to kinetochores from G1 to metaphase, transfers to the spindle after metaphase, and accumulates at the spindle midzone late in anaphase. Ipl1p kinase activity increases at anaphase, and ipl1 mutants can stabilize fragile spindles. As the spindle disassembles, Ipl1p follows the plus ends of the depolymerizing spindle microtubules. Many Ipl1p substrates colocalize with Ipl1p to the spindle midzone, identifying additional proteins that may regulate spindle disassembly. We propose that Ipl1p regulates both the kinetochore and interpolar microtubule plus ends to regulate its various mitotic functions.

scholarly journals Nucleocytoplasmic transport in the midzone membrane domain controls yeast mitotic spindle disassembly

2015 ◽  
Vol 209 (3) ◽  
pp. 387-402 ◽  
Author(s):  
Rafael Lucena ◽  
Noah Dephoure ◽  
Steve P. Gygi ◽  
Douglas R. Kellogg ◽  
Victor A. Tallada ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Nucleocytoplasmic Transport ◽  
Membrane Domain ◽  
Aaa Atpase ◽  
Membrane Compartment ◽  
Spindle Disassembly ◽  
Spindle Midzone ◽  
Anaphase B

During each cell cycle, the mitotic spindle is efficiently assembled to achieve chromosome segregation and then rapidly disassembled as cells enter cytokinesis. Although much has been learned about assembly, how spindles disassemble at the end of mitosis remains unclear. Here we demonstrate that nucleocytoplasmic transport at the membrane domain surrounding the mitotic spindle midzone, here named the midzone membrane domain (MMD), is essential for spindle disassembly in Schizosaccharomyces pombe cells. We show that, during anaphase B, Imp1-mediated transport of the AAA-ATPase Cdc48 protein at the MMD allows this disassembly factor to localize at the spindle midzone, thereby promoting spindle midzone dissolution. Our findings illustrate how a separate membrane compartment supports spindle disassembly in the closed mitosis of fission yeast.

scholarly journals Methylation of PLK1 by SET7/9 ensures accurate kinetochore–microtubule dynamics

2019 ◽  
Vol 12 (6) ◽  
pp. 462-476 ◽  
Author(s):  
Ruoying Yu ◽  
Huihui Wu ◽  
Hazrat Ismail ◽  
Shihao Du ◽  
Jun Cao ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Kinase Activity ◽  
Genomic Stability ◽  
Lysine Methylation ◽  
Mitotic Chromosomes ◽  
Methyltransferase Activity ◽  
Sister Chromatids ◽  
Spindle Microtubules ◽  
Chemical Inhibition ◽  
Early Mitosis

Abstract Faithful segregation of mitotic chromosomes requires bi-orientation of sister chromatids, which relies on the sensing of correct attachments between spindle microtubules and kinetochores. Although the mechanisms underlying PLK1 activation have been extensively studied, the regulatory mechanisms that couple PLK1 activity to accurate chromosome segregation are not well understood. In particular, PLK1 is implicated in stabilizing kinetochore–microtubule attachments, but how kinetochore PLK1 activity is regulated to avoid hyperstabilized kinetochore–microtubules in mitosis remains elusive. Here, we show that kinetochore PLK1 kinase activity is modulated by SET7/9 via lysine methylation during early mitosis. The SET7/9-elicited dimethylation occurs at the Lys191 of PLK1, which tunes down its activity by limiting ATP utilization. Overexpression of the non-methylatable PLK1 mutant or chemical inhibition of SET7/9 methyltransferase activity resulted in mitotic arrest due to destabilized kinetochore–microtubule attachments. These data suggest that kinetochore PLK1 is essential for stable kinetochore–microtubule attachments and methylation by SET7/9 promotes dynamic kinetochore–microtubule attachments for accurate error correction. Our findings define a novel homeostatic regulation at the kinetochore that integrates protein phosphorylation and methylation with accurate chromosome segregation for maintenance of genomic stability.

scholarly journals Genes Involved in Sister Chromatid Separation and Segregation in the Budding Yeast Saccharomyces cerevisiae

Genetics ◽  
2001 ◽  
Vol 159 (2) ◽  
pp. 453-470
Author(s):  
Sue Biggins ◽  
Needhi Bhalla ◽  
Amy Chang ◽  
Dana L Smith ◽  
Andrew W Murray
Keyword(s):  
Chromosome Segregation ◽  
Sister Chromatid ◽  
Mitotic Spindle ◽  
Budding Yeast ◽  
Temperature Sensitive ◽  
Chromosome Behavior ◽  
Yeast Saccharomyces Cerevisiae ◽  
Sister Chromatids ◽  
Marked Chromosome ◽  
Sister Chromatid Separation

Abstract Accurate chromosome segregation requires the precise coordination of events during the cell cycle. Replicated sister chromatids are held together while they are properly attached to and aligned by the mitotic spindle at metaphase. At anaphase, the links between sisters must be promptly dissolved to allow the mitotic spindle to rapidly separate them to opposite poles. To isolate genes involved in chromosome behavior during mitosis, we microscopically screened a temperature-sensitive collection of budding yeast mutants that contain a GFP-marked chromosome. Nine LOC (loss of cohesion) complementation groups that do not segregate sister chromatids at anaphase were identified. We cloned the corresponding genes and performed secondary tests to determine their function in chromosome behavior. We determined that three LOC genes, PDS1, ESP1, and YCS4, are required for sister chromatid separation and three other LOC genes, CSE4, IPL1, and SMT3, are required for chromosome segregation. We isolated alleles of two genes involved in splicing, PRP16 and PRP19, which impair α-tubulin synthesis thus preventing spindle assembly, as well as an allele of CDC7 that is defective in DNA replication. We also report an initial characterization of phenotypes associated with the SMT3/SUMO gene and the isolation of WSS1, a high-copy smt3 suppressor.

scholarly journals Differential requirement for Bub1 and Bub3 in regulation of meiotic versus mitotic chromosome segregation

2020 ◽  
Vol 219 (4) ◽  
Author(s):  
Gisela Cairo ◽  
Anne M. MacKenzie ◽  
Soni Lacefield
Keyword(s):  
Chromosome Segregation ◽  
Protein Phosphatase ◽  
Mitotic Chromosome ◽  
Budding Yeast ◽  
Meiotic Chromosome ◽  
Protein Phosphatase 1 ◽  
Aurora B ◽  
Chromosome Missegregation ◽  
Anaphase Onset ◽  
Spindle Microtubules

Accurate chromosome segregation depends on the proper attachment of kinetochores to spindle microtubules before anaphase onset. The Ipl1/Aurora B kinase corrects improper attachments by phosphorylating kinetochore components and so releasing aberrant kinetochore–microtubule interactions. The localization of Ipl1 to kinetochores in budding yeast depends upon multiple pathways, including the Bub1–Bub3 pathway. We show here that in meiosis, Bub3 is crucial for correction of attachment errors. Depletion of Bub3 results in reduced levels of kinetochore-localized Ipl1 and concomitant massive chromosome missegregation caused by incorrect chromosome–spindle attachments. Depletion of Bub3 also results in shorter metaphase I and metaphase II due to premature localization of protein phosphatase 1 (PP1) to kinetochores, which antagonizes Ipl1-mediated phosphorylation. We propose a new role for the Bub1–Bub3 pathway in maintaining the balance between kinetochore localization of Ipl1 and PP1, a balance that is essential for accurate meiotic chromosome segregation and timely anaphase onset.

scholarly journals Disruption of Centrosome Structure, Chromosome Segregation, and Cytokinesis by Misexpression of Human Cdc14A Phosphatase

2002 ◽  
Vol 13 (7) ◽  
pp. 2289-2300 ◽  
Author(s):  
Brett K. Kaiser ◽  
Zachary A. Zimmerman ◽  
Harry Charbonneau ◽  
Peter K. Jackson
Keyword(s):  
Cell Cycle ◽  
Phosphatase Activity ◽  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Genomic Stability ◽  
Mitotic Exit ◽  
Protein Abundance ◽  
Cyclin Dependent Kinase ◽  
Chromosome Partitioning

In budding yeast, the Cdc14p phosphatase activates mitotic exit by dephosphorylation of specific cyclin-dependent kinase (Cdk) substrates and seems to be regulated by sequestration in the nucleolus until its release in mitosis. Herein, we have analyzed the two human homologs of Cdc14p, hCdc14A and hCdc14B. We demonstrate that the human Cdc14A phosphatase is selective for Cdk substrates in vitro and that although the protein abundance and intrinsic phosphatase activity of hCdc14A and B vary modestly during the cell cycle, their localization is cell cycle regulated. hCdc14A dynamically localizes to interphase but not mitotic centrosomes, and hCdc14B localizes to the interphase nucleolus. These distinct patterns of localization suggest that each isoform of human Cdc14 likely regulates separate cell cycle events. In addition, hCdc14A overexpression induces the loss of the pericentriolar markers pericentrin and γ-tubulin from centrosomes. Overproduction of hCdc14A also causes mitotic spindle and chromosome segregation defects, defective karyokinesis, and a failure to complete cytokinesis. Thus, the hCdc14A phosphatase appears to play a role in the regulation of the centrosome cycle, mitosis, and cytokinesis, thereby influencing chromosome partitioning and genomic stability in human cells.

Regulation of Mitosis

1969 ◽  
Vol 5 (3) ◽  
pp. 745-755
Author(s):  
W. T. JACKSON
Keyword(s):  
Mitotic Spindle ◽  
Time Lapse ◽  
Polarization Microscopy ◽  
Animal Cells ◽  
Higher Plant ◽  
Competitive Antagonism ◽  
Dividing Cells ◽  
Spindle Microtubules ◽  
Giant Nuclei

Earlier studies on the effects of the herbicide isopropyl N-phenylcarbamate (IPC) on mitosis revealed blocked metaphases, multinucleate cells, giant nuclei and an increase in number of partly contracted chromosomes. It was assumed that IPC, like colchicine, was causing these effects by disruption of the spindle apparatus by destroying the spindle microtubules. The animal hormone melatonin causes an increase in birefringence of the mitotic spindle in animal cells, presumably by increasing the number of microtubules. We have studied the effects of IPC, melatonin, and combinations of the two on mitosis in dividing endosperm cells of the African blood lily (Haemanthus katherinae Baker) in vivo by phase-contrast and polarization microscopy. Both qualitative and quantitative data are presented. Interpretation of these results has been aided materially by a time-lapse cinemicrographic analysis of dividing cells subjected to 1 and 10 p.p.m. IPC (unpublished) and by an accompanying fine-structural analysis of untreated and IPC-treated cells. Mitosis was disrupted by 0.01-10 p.p.m. IPC, the severity of the effect depending on both concentration and stage of mitosis of the cell at the time of treatment. Concentrations of IPC that caused cessation of chromosome movement also caused loss of birefringence of the mitotic spindle. Melatonin increased birefringence of the mitotic spindle in these plant cells and partly nullified the adverse effects of IPC. The results of this study demonstrate that the herbicide IPC, under our conditions, causes disruption of mitosis and loss of birefringence of the spindle. And it has been established that an animal hormone is capable of increasing the birefringence, and presumably the number of microtubules, of the mitotic spindle in dividing endosperm cells of a higher plant. Although melatonin is capable of partly nullifying the effects of IPC, a competitive antagonism is not postulated.

scholarly journals Reductionism at the vertebrate kinetochore

2012 ◽  
Vol 200 (1) ◽  
pp. 7-8 ◽  
Author(s):  
Ana Stankovic ◽  
Lars E.T. Jansen
Keyword(s):  
Chromosome Segregation ◽  
Protein Interactions ◽  
Mitotic Spindle ◽  
De Novo ◽  
Large Structure ◽  
Cell Biol ◽  
Spindle Microtubules ◽  
The Creation

The kinetochore forms the site of attachment for mitotic spindle microtubules driving chromosome segregation. The interdependent protein interactions in this large structure have made it difficult to dissect the function of its components. In this issue, Hori et al. (2013. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201210106) present a novel and powerful methodology to address the sufficiency of individual proteins for the creation of a functional de novo centromere.

scholarly journals Mitotic chromosome length scales in response to both cell and nuclear size

2015 ◽  
Vol 209 (5) ◽  
pp. 645-652 ◽  
Author(s):  
Anne-Marie Ladouceur ◽  
Jonas F. Dorn ◽  
Paul S. Maddox
Keyword(s):  
Cell Size ◽  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Mitotic Chromosome ◽  
Time Lapse ◽  
Chromosome Length ◽  
Nuclear Size ◽  
Multicellular Development ◽  
Length Regulation ◽  
Cellular Integrity

Multicellular development requires that cells reduce in size as a result of consecutive cell divisions without increase in embryo volume. To maintain cellular integrity, organelle size adapts to cell size throughout development. During mitosis, the longest chromosome arm must be shorter than half of the mitotic spindle for proper chromosome segregation. Using high-resolution time-lapse microscopy of living Caenorhabditis elegans embryos, we have quantified the relation between cell size and chromosome length. In control embryos, chromosome length scaled to cell size. Artificial reduction of cell size resulted in a shortening of chromosome length, following a trend predicted by measurements from control embryos. Disturbing the RAN (Ras-related nuclear protein)-GTP gradient decoupled nuclear size from cell size and resulted in chromosome scaling to nuclear size rather than cell size; smaller nuclei contained shorter chromosomes independent of cell size. In sum, quantitative analysis relating cell, nuclear, and chromosome size predicts two levels of chromosome length regulation: one through cell size and a second in response to nuclear size.

scholarly journals SUMO proteases SENP3 and SENP5 spatiotemporally regulate the kinase activity of Aurora A

2021 ◽  
Author(s):  
Bin Yu ◽  
Qiaoyu Lin ◽  
Chao Huang ◽  
Boyan Zhang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Chromosome Segregation ◽  
Mitotic Spindle ◽  
Kinase Activity ◽  
In Vitro Assays ◽  
Aurora A ◽  
Sumo Proteases ◽  
Spatiotemporal Control ◽  
Early Mitosis

Precise chromosome segregation is mediated by a well-assembled mitotic spindle, which requires balance of the kinase activity of Aurora A (AurA). However, how this kinase activity is regulated remains largely unclear. Here, using in vivo and in vitro assays, we report that conjugation of SUMO2 with AurA at K258 in early mitosis promotes the kinase activity of AurA and facilitates the binding with its activator, Bora. Knockdown of the SUMO proteases SENP3 and SENP5 disrupted the deSUMOylation of AurA, leading to an increased kinase activity and abnormalities in spindle assembly and chromosomes segregation which could be rescued by suppressing the kinase activity of AurA. Collectively, these results demonstrate that SENP3 and SENP5 deSUMOylate AurA to render a spatiotemporal control on its kinase activity in mitosis.

Sign in / Sign up

Export Citation Format

Share Document