scholarly journals Chromosome length and perinuclear attachment constrain resolution of DNA intertwines

2014 ◽  
Vol 206 (6) ◽  
pp. 719-733 ◽  
Author(s):  
Iris Titos ◽  
Tsvetomira Ivanova ◽  
Manuel Mendoza
Keyword(s):  
Chromosome Segregation ◽  
Topoisomerase Ii ◽  
Chromosome Length ◽  
Genomic Region ◽  
Critical Feature ◽  
Topological Constraints ◽  
Rdna Array ◽  
Topo Ii ◽  
Mutant Cells ◽  
Segregation Of Chromosomes

To allow chromosome segregation, topoisomerase II (topo II) must resolve sister chromatid intertwines (SCI) formed during deoxynucleic acid (DNA) replication. How this process extends to the full genome is not well understood. In budding yeast, the unique structure of the ribosomal DNA (rDNA) array is thought to cause late SCI resolution of this genomic region during anaphase. In this paper, we show that chromosome length, and not the presence of rDNA repeats, is the critical feature determining the time of topo II–dependent segregation. Segregation of chromosomes lacking rDNA also requires the function of topo II in anaphase, and increasing chromosome length aggravates missegregation in topo II mutant cells. Furthermore, anaphase Stu2-dependent microtubule dynamics are critical for separation of long chromosomes. Finally, defects caused by topo II or Stu2 impairment depend on attachment of telomeres to the nuclear envelope. We propose that topological constraints imposed by chromosome length and perinuclear attachment determine the amount of SCI that topo II and dynamic microtubules resolve during anaphase.

scholarly journals MCPH1 Lack of Function Enhances Mitotic Cell Sensitivity Caused by Catalytic Inhibitors of Topo II

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 406
Author(s):  
María Arroyo ◽  
Antonio Sánchez ◽  
Ana Cañuelo ◽  
Rosalía F. Heredia-Molina ◽  
Eduardo Martínez-Molina ◽  
...  
Keyword(s):  
Cell Death ◽  
Chromosome Segregation ◽  
Topoisomerase Ii ◽  
Mitotic Cell ◽  
Primary Microcephaly ◽  
Checkpoint Response ◽  
Checkpoint Pathway ◽  
Chromosome Alignment ◽  
Topo Ii ◽  
A Minor

The capacity of Topoisomerase II (Topo II) to remove DNA catenations that arise after replication is essential to ensure faithful chromosome segregation. Topo II activity is monitored during G2 by a specific checkpoint pathway that delays entry into mitosis until the chromosomes are properly decatenated. Recently, we demonstrated that the mitotic defects that are characteristic of cells depleted of MCPH1 function, a protein mutated in primary microcephaly, are not a consequence of a weakened G2 decatenation checkpoint response. However, the mitotic defects could be accounted for by a minor defect in the activity of Topo II during G2/M. To test this hypothesis, we have tracked at live single cell resolution the dynamics of mitosis in MCPH1 depleted HeLa cells upon catalytic inhibition of Topo II. Our analyses demonstrate that neither chromosome alignment nor segregation are more susceptible to minor perturbation in decatenation in MCPH1 deficient cells, as compared with control cells. Interestingly, MCPH1 depleted cells were more prone to mitotic cell death when decatenation was perturbed. Furthermore, when the G2 arrest that was induced by catalytic inhibition of Topo II was abrogated by Chk1 inhibition, the incidence of mitotic cell death was also increased. Taken together, our data suggest that the MCPH1 lack of function increases mitotic cell hypersensitivity to the catalytic inhibition of Topo II.

scholarly journals A noncatalytic function of the topoisomerase II CTD in Aurora B recruitment to inner centromeres during mitosis

2016 ◽  
Vol 213 (6) ◽  
pp. 651-664 ◽  
Author(s):  
Heather Edgerton ◽  
Marnie Johansson ◽  
Daniel Keifenheim ◽  
Soumya Mukherjee ◽  
Jeremy M. Chacón ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Binding Site ◽  
Chromosome Segregation ◽  
Topoisomerase Ii ◽  
Histone H3 ◽  
Aurora B ◽  
Topoisomerase Iiα ◽  
Dna Topoisomerase ◽  
Topo Ii ◽  
Dna Topoisomerase Iiα

Faithful chromosome segregation depends on the precise timing of chromatid separation, which is enforced by checkpoint signals generated at kinetochores. Here, we provide evidence that the C-terminal domain (CTD) of DNA topoisomerase IIα (Topo II) provides a novel function at inner centromeres of kinetochores in mitosis. We find that the yeast CTD is required for recruitment of the tension checkpoint kinase Ipl1/Aurora B to inner centromeres in metaphase but is not required in interphase. Conserved CTD SUMOylation sites are required for Ipl1 recruitment. This inner-centromere CTD function is distinct from the catalytic activity of Topo II. Genetic and biochemical evidence suggests that Topo II recruits Ipl1 via the Haspin–histone H3 threonine 3 phosphorylation pathway. Finally, Topo II and Sgo1 are equally important for Ipl1 recruitment to inner centromeres. This indicates H3 T3-Phos/H2A T120-Phos is a universal epigenetic signature that defines the eukaryotic inner centromere and provides the binding site for Ipl1/Aurora B.

scholarly journals CENP-A and topoisomerase-II antagonistically affect chromosome length

2017 ◽  
Vol 216 (9) ◽  
pp. 2645-2655 ◽  
Author(s):  
A.-M. Ladouceur ◽  
Rajesh Ranjan ◽  
Lydia Smith ◽  
Tanner Fadero ◽  
Jennifer Heppert ◽  
...  
Keyword(s):  
Self Assembly ◽  
Topoisomerase Ii ◽  
Chromosome Length ◽  
Chromosome Size ◽  
Mitotic Chromosomes ◽  
Nuclear Trafficking ◽  
C Elegans ◽  
Protein Levels ◽  
Histone H3 Variant ◽  
Topo Ii

The size of mitotic chromosomes is coordinated with cell size in a manner dependent on nuclear trafficking. In this study, we conducted an RNA interference screen of the Caenorhabditis elegans nucleome in a strain carrying an exceptionally long chromosome and identified the centromere-specific histone H3 variant CENP-A and the DNA decatenizing enzyme topoisomerase-II (topo-II) as candidate modulators of chromosome size. In the holocentric organism C. elegans, CENP-A is positioned periodically along the entire length of chromosomes, and in mitosis, these genomic regions come together linearly to form the base of kinetochores. We show that CENP-A protein levels decreased through development coinciding with chromosome-size scaling. Partial loss of CENP-A protein resulted in shorter mitotic chromosomes, consistent with a role in setting chromosome length. Conversely, topo-II levels were unchanged through early development, and partial topo-II depletion led to longer chromosomes. Topo-II localized to the perimeter of mitotic chromosomes, excluded from the centromere regions, and depletion of topo-II did not change CENP-A levels. We propose that self-assembly of centromeric chromatin into an extended linear array promotes elongation of the chromosome, whereas topo-II promotes chromosome-length shortening.

scholarly journals Linker histone H1.8 inhibits chromatin-binding of condensins and DNA topoisomerase II to tune chromosome length and individualization

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Pavan Choppakatla ◽  
Bastiaan Dekker ◽  
Erin E Cutts ◽  
Alessandro Vannini ◽  
Job Dekker ◽  
...  
Keyword(s):  
Topoisomerase Ii ◽  
Mitotic Chromosome ◽  
Chromosome Length ◽  
Chromosome Morphology ◽  
Linker Histone ◽  
Dna Topoisomerase Ii ◽  
Dna Amount ◽  
Dna Topoisomerase ◽  
Topo Ii

DNA loop extrusion by condensins and decatenation by DNA topoisomerase II (topo II) are thought to drive mitotic chromosome compaction and individualization. Here, we reveal that the linker histone H1.8 antagonizes condensins and topo II to shape mitotic chromosome organization. In vitro chromatin reconstitution experiments demonstrate that H1.8 inhibits binding of condensins and topo II to nucleosome arrays. Accordingly, H1.8 depletion in Xenopus egg extracts increased condensins and topo II levels on mitotic chromatin. Chromosome morphology and Hi-C analyses suggest that H1.8 depletion makes chromosomes thinner and longer through shortening the average loop size and reducing the DNA amount in each layer of mitotic loops. Furthermore, excess loading of condensins and topo II to chromosomes by H1.8 depletion causes hyper-chromosome individualization and dispersion. We propose that condensins and topo II are essential for chromosome individualization, but their functions are tuned by the linker histone to keep chromosomes together until anaphase.

scholarly journals Prp4 kinase is required for proper segregation of chromosomes during meiosis in Schizosaccharomyces pombe.

1970 ◽  
Vol 60 (4) ◽  
Author(s):  
Miroslava Pozgajova ◽  
Lubos Cipak ◽  
Anna Trakovicka
Keyword(s):  
Protein Kinase ◽  
Schizosaccharomyces Pombe ◽  
Chromosome Segregation ◽  
Crucial Role ◽  
Phosphorylation Of Proteins ◽  
Complex Process ◽  
Sensitive Allele ◽  
Mutant Cells ◽  
Segregation Of Chromosomes

Chromosome segregation during meiosis is a complex process, which leads to production of four haploid gametes from two precursor cells. Reversible phosphorylation of proteins plays a crucial role in this process. The Schizosaccharomyces pombe Prp4 is an essential serine/threonine protein kinase, which belongs to the Clk/Sty family. To study the role of Prp4 in meiosis, we analysed chromosome segregation in a strain carrying conditional analog-sensitive allele of Prp4 protein kinase (prp4-as2). Our data show, that Prp4 protein kinase plays important role in chromosome segregation during meiosis, as revealed by enhanced missegregation of chromosomes in prp4-as2 mutant cells.

Anticancer Activity and Topoisomerase II Inhibition of Naphthalimides with ω-Hydroxylalkylamine Side-Chains of Different Lengths

2019 ◽  
Vol 15 (5) ◽  
pp. 550-560
Author(s):  
Mateusz D. Tomczyk ◽  
Anna Byczek-Wyrostek ◽  
Klaudia Strama ◽  
Martyna Wawszków ◽  
Przemysław Kasprzycki ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Cancer Cells ◽  
Cell Lines ◽  
Inhibitory Activity ◽  
Topoisomerase Ii ◽  
Significant Activity ◽  
Anticancer Activities ◽  
Human Colon Cancer ◽  
Substitution Pattern ◽  
Topo Ii

Background: The substituted 1,8-Naphthalimides (1H-benzo[de]isoquinoline-1,3(2H)- diones) are known as DNA intercalators stabilizing DNA-Topoisomerase II complexes. This interaction disrupts the cleavage-relegation equilibrium of Topo II, resulting in formation of broken strands of DNA. Objective: To investigate the influence of type of substituents and substitution positions in 1,8- naphthalimde skeleton on the inhibition of Topoisomerase II activity. Methods: The starting 1,8-naphthalimide were prepared from acenaphthene by introduction of appropriate substituents followed by condensation with ω-hydroxylakylamines of different chain length. The substituents were introduced to 1,8-naphthalimide molecule by nucleophilic substitution of leaving groups like nitro or bromo present in 4 or 4,5- positions using the ω- hydroxylalkylamines. The bioactivity of obtained compounds was examined in model cell lines. Results: Antiproliferative activity of selected compounds against HCT 116 human colon cancer cells, human non-small cell lung cells A549 and non-tumorigenic BEAS-2B human bronchial epithelium cells was examined. Several of investigated compounds exhibit a significant activity (IC50 µM to 7 µM) against model cancer cell lines. It was demonstrated that upon treatment with concentration of 200 µM, all derivatives display Topo II inhibitory activity, which may be compared with activity of Amonafide. Conclusion: The replacement of the nitro groups in the chromophore slightly reduces its anticancer activities, whereas the presence of both nitro group and ω-hydroxylalkylamine chain resulted in seriously increased anticancer activity. Obtained compounds showed Topo II inhibitory activity, moreover, influence of the substitution pattern on the ability to inhibit Topo II activity and cancer cells proliferation was observed.

fumble Encodes a Pantothenate Kinase Homolog Required for Proper Mitosis and Meiosis in Drosophila melanogaster

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1267-1276
Author(s):  
Katayoun Afshar ◽  
Pierre Gönczy ◽  
Stephen DiNardo ◽  
Steven A Wasserman
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Cell Division Cycle ◽  
Protein Isoforms ◽  
Pantothenate Kinase ◽  
Male Germline ◽  
Dividing Cells ◽  
Mutant Cells ◽  
Mitosis And Meiosis

Abstract A number of fundamental processes comprise the cell division cycle, including spindle formation, chromosome segregation, and cytokinesis. Our current understanding of these processes has benefited from the isolation and analysis of mutants, with the meiotic divisions in the male germline of Drosophila being particularly well suited to the identification of the required genes. We show here that the fumble (fbl) gene is required for cell division in Drosophila. We find that dividing cells in fbl-deficient testes exhibit abnormalities in bipolar spindle organization, chromosome segregation, and contractile ring formation. Cytological analysis of larval neuroblasts from null mutants reveals a reduced mitotic index and the presence of polyploid cells. Molecular analysis demonstrates that fbl encodes three protein isoforms, all of which contain a domain with high similarity to the pantothenate kinases of A. nidulans and mouse. The largest Fumble isoform is dispersed in the cytoplasm during interphase, concentrates around the spindle at metaphase, and localizes to the spindle midbody at telophase. During early embryonic development, the protein localizes to areas of membrane deposition and/or rearrangement, such as the metaphase and cellularization furrows. Given the role of pantothenate kinase in production of Coenzyme A and in phospholipid biosynthesis, this pattern of localization is suggestive of a role for fbl in membrane synthesis. We propose that abnormalities in synthesis and redistribution of membranous structures during the cell division cycle underlie the cell division defects in fbl mutant cells.

Synthesis and anticancer evaluation of sulfur containing 9-anilinoacridines

2021 ◽  
Vol 16 ◽  
Author(s):  
Pranav Gupta ◽  
Radhika V. Kumar ◽  
Chul-Hoon Kwon ◽  
Zhe-Sheng Chen
Keyword(s):  
Cell Cycle ◽  
Anticancer Activity ◽  
Topoisomerase Ii ◽  
Critical Role ◽  
K562 Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
In Vivo Models ◽  
Topo Ii ◽  
Sulfur Containing

Background: DNA topoisomerases are a class of enzymes that play a critical role in fundamental biological processes of replication, transcription, recombination, repair and chromatin remodeling. Amsacrine (m-AMSA), the best-known compound of 9-anilinoacridines series was one of the first DNA-intercalating agents to be considered as a Topoisomerase II inhibitor. Objective: A series of sulfur containing 9-anilinoacridines related to amsacrine were synthesized and evaluated for their anticancer activity. Methods: Cell viability was assessed by the MTT assay. The topoisomerase II inhibitory assay was performed using the Human topoisomerase II Assay kit and flow cytometry was used to evaluate the effects on cell cycle of K562 cells. Molecular docking was performed using Schrödinger Maestro program. Results: Compound 36 was found to be the most cytotoxic of the sulfide series against SW620, K562, and MCF-7. The limited SAR suggested the importance of the methansulfonamidoacetamide side chain functionality, the lipophilicity and relative metabolic stability of 36 in contributing to the cytotoxicity. Topoisomerase II α inhibitory activity appeared to be involved in the cytotoxicity of 36 through inhibition of decatenation of kinetoplast DNA (kDNA) in a concentration dependent manner. Cell cycle analysis further showed the Topo II inhibition through accumulation of K562 cells in G2/M phase of cell cycle. Docking of 36 into the Topo II α-DNA complex suggested that it may be an allosteric inhibitor of Topo II α. Conclusion: Compound 36 exhibits anticancer activity by inhibiting topoisomerase II and it could further be evaluated in in vivo models.

CSE1 and CSE2, two new genes required for accurate mitotic chromosome segregation in Saccharomyces cerevisiae

1993 ◽  
Vol 13 (8) ◽  
pp. 4691-4702 ◽  
Author(s):  
Z Xiao ◽  
J T McGrew ◽  
A J Schroeder ◽  
M Fitzgerald-Hayes
Keyword(s):  
Chromosome Segregation ◽  
Leucine Zipper ◽  
Mitotic Chromosome ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
New Genes ◽  
Marked Chromosome ◽  
Cold Sensitive ◽  
Basic Region ◽  
Segregation Of Chromosomes

By monitoring the mitotic transmission of a marked chromosome bearing a defective centromere, we have identified conditional alleles of two genes involved in chromosome segregation (cse). Mutations in CSE1 and CSE2 have a greater effect on the segregation of chromosomes carrying mutant centromeres than on the segregation of chromosomes with wild-type centromeres. In addition, the cse mutations cause predominantly nondisjunction rather than loss events but do not cause a detectable increase in mitotic recombination. At the restrictive temperature, cse1 and cse2 mutants accumulate large-budded cells, with a significant fraction exhibiting aberrant binucleate morphologies. We cloned the CSE1 and CSE2 genes by complementation of the cold-sensitive phenotypes. Physical and genetic mapping data indicate that CSE1 is linked to HAP2 on the left arm of chromosome VII and CSE2 is adjacent to PRP2 on chromosome XIV. CSE1 is essential and encodes a novel 109-kDa protein. CSE2 encodes a 17-kDa protein with a putative basic-region leucine zipper motif. Disruption of CSE2 causes chromosome missegregation, conditional lethality, and slow growth at the permissive temperature.

scholarly journals Mitotic chromatin condensation in vitro using somatic cell extracts and nuclei with variable levels of endogenous topoisomerase II.

1990 ◽  
Vol 111 (6) ◽  
pp. 2839-2850 ◽  
Author(s):  
E R Wood ◽  
W C Earnshaw
Keyword(s):  
Topoisomerase Ii ◽  
Condensation Reaction ◽  
Chromatin Condensation ◽  
Condensation Process ◽  
Interphase Nuclei ◽  
Culture Cells ◽  
Cell Extracts ◽  
Topo Ii ◽  
Species Specific

We report the development of a new method for producing mitotic extracts from tissue culture cells. These extracts reproducibly promote the condensation of chromatin in vitro when incubated with purified interphase nuclei. This condensation reaction is not species specific, since nuclei from chicken, human, and hamster cell lines all undergo chromatin condensation upon incubation with the extract. We have used this extract to investigate the role of DNA topoisomerase II (topo II) in the chromosome condensation process. Chromatin condensation does not require the presence of soluble topo II in the mitotic extract. However, the extent of formation of discrete chromosome-like structures correlates with the level of endogenous topo II present in the interphase nuclei. Our results further suggest that chromatin condensation in this extract may involve two processes: chromatin compaction and resolution into discrete chromosomes.

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