scholarly journals Topoisomerase II SUMOylation activates a metaphase checkpoint via Haspin and Aurora B kinases

2019 ◽  
Vol 219 (1) ◽  
Author(s):  
Nootan Pandey ◽  
Daniel Keifenheim ◽  
Makoto Michael Yoshida ◽  
Victoria A. Hassebroek ◽  
Caitlin Soroka ◽  
...  
Keyword(s):  
Topoisomerase Ii ◽  
Histone H3 ◽  
Aurora B ◽  
Additional Time ◽  
Checkpoint Activation ◽  
Present Evidence ◽  
The Core ◽  
Anaphase Onset ◽  
Topo Ii ◽  
Insight Into

Topoisomerase II (Topo II) is essential for mitosis since it resolves sister chromatid catenations. Topo II dysfunction promotes aneuploidy and drives cancer. To protect from aneuploidy, cells possess mechanisms to delay anaphase onset when Topo II is perturbed, providing additional time for decatenation. Molecular insight into this checkpoint is lacking. Here we present evidence that catalytic inhibition of Topo II, which activates the checkpoint, leads to SUMOylation of the Topo II C-terminal domain (CTD). This modification triggers mobilization of Aurora B kinase from inner centromeres to kinetochore proximal centromeres and the core of chromosome arms. Aurora B recruitment accompanies histone H3 threonine-3 phosphorylation and requires Haspin kinase. Strikingly, activation of the checkpoint depends both on Haspin and Aurora B. Moreover, mutation of the conserved CTD SUMOylation sites perturbs Aurora B recruitment and checkpoint activation. The data indicate that SUMOylated Topo II recruits Aurora B to ectopic sites, constituting the molecular trigger of the metaphase checkpoint when Topo II is catalytically inhibited.

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 Topoisomerase II inhibitors induce cGAS-STING dependent inflammation resulting in cytokine induction and immune checkpoint activation

2019 ◽  
Author(s):  
R. D. A Wilkinson ◽  
N. McCabe ◽  
E. E. Parkes ◽  
E.M. Barros ◽  
D. I. Johnston ◽  
...  
Keyword(s):  
Immune Checkpoint ◽  
Topoisomerase Ii ◽  
Immune Cell ◽  
Immune Checkpoint Blockade ◽  
Interferon Response ◽  
Checkpoint Activation ◽  
Checkpoint Gene ◽  
Cytokine Induction ◽  
Topo Ii ◽  
Sting Pathway

AbstractTumours with genomic instability demonstrate enhanced immunogenicity and potential for response to immune checkpoint blockade (ICB). We previously demonstrated activation of the cGAS-STING pathway following loss of DNA repair, resulting in cytokine induction, lymphocytic infiltration and immune checkpoint activation. Here we explore the role of chemotherapies in inducing this innate immune response, identifying topoisomerase II (topo-II) inhibitors, particularly doxorubicin and epirubicin, as potent inducers of a cGAS-STING dependent interferon response. Mechanistically, topo-II inhibition resulted in significant induction of cytoplasmic DNA and subsequent micronuclei formation, a requirement for efficient cGAS-STING activation and consequent cytokine and immune checkpoint gene induction. Importantly, increased cytokine and immune checkpoint gene expression, as well as increased immune cell infiltration, was also observed in patient derived breast tumour biopsies following topo-II inhibitor-based treatment. Taken together, this study indicates topo-II inhibitors such as doxorubicin, may be best placed to induce immunogenic inflammation, and thereby increase responses to ICB therapies.SignificanceThis work demonstrates how topo-II inhibitors induce STING-pathway activation, cytokine induction and immune checkpoint protein upregulation in cancer cells and provides a rationale for combining topo-II inhibitors with ICB therapy in early breast cancer.

scholarly journals A functional 125-kDa core polypeptide of fission yeast DNA topoisomerase II.

1991 ◽  
Vol 11 (12) ◽  
pp. 6093-6102 ◽  
Author(s):  
K Shiozaki ◽  
M Yanagida
Keyword(s):  
Amino Acids ◽  
Fission Yeast ◽  
Topoisomerase Ii ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Limited Proteolysis ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
The Core ◽  
Topo Ii

We purified fission yeast DNA topoisomerase II (topo II) to apparent homogeneity. It consists of a single 165-kDa polypeptide in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and, upon treatment with a bifunctional reagent, doubles its molecular weight. Limited proteolysis of intact topo II by papain produces a 125-kDa core, which lacks the N-terminal 75 and the C-terminal approximately 260 amino acids but still contains regions similar to those of bacterial or phage T4 topo II subunits. The core retains relaxing and unknotting activities. Further digestion inactivates the core, cleaving it at the middle of the GyrB-like domain and at the beginning of the GyrA-like domain. Therefore, papain appears to cleave spatially distinct subdomains of topo II. We made top2 mutant genes deleted of the C-terminal 286 or N-terminal 74 amino acids, which can substitute for the wild-type top2+ gene in mitosis and meiosis. However, a mutant containing deletions of both termini cannot rescue the top2 null mutant, despite the fact that the product is enzymatically active. Therefore, the top2 product of the doubly truncated gene may not fulfill all of the in vivo requirements for top2+ function.

scholarly journals In vivo dissection of the chromosome condensation machinery

2002 ◽  
Vol 156 (5) ◽  
pp. 805-815 ◽  
Author(s):  
Brigitte D. Lavoie ◽  
Eileen Hogan ◽  
Douglas Koshland
Keyword(s):  
Topoisomerase Ii ◽  
Mitotic Chromosome ◽  
Chromosome Structure ◽  
Histone H3 ◽  
Chromosome Condensation ◽  
Chromatin Binding ◽  
Condensin Complex ◽  
Topo Ii ◽  
Structural Maintenance Of Chromosome

The machinery mediating chromosome condensation is poorly understood. To begin to dissect the in vivo function(s) of individual components, we monitored mitotic chromosome structure in mutants of condensin, cohesin, histone H3, and topoisomerase II (topo II). In budding yeast, both condensation establishment and maintenance require all of the condensin subunits, but not topo II activity or phospho-histone H3. Structural maintenance of chromosome (SMC) protein 2, as well as each of the three non-SMC proteins (Ycg1p, Ycs4p, and Brn1p), was required for chromatin binding of the condensin complex in vivo. Using reversible condensin alleles, we show that chromosome condensation does not involve an irreversible modification of condensin or chromosomes. Finally, we provide the first evidence of a mechanistic link between condensin and cohesin function. A model discussing the functional interplay between cohesin and condensin is presented.

scholarly journals Coordinated Requirements of Human Topo II and Cohesin for Metaphase Centromere Alignment under Mad2-dependent Spindle Checkpoint Surveillance

2006 ◽  
Vol 17 (5) ◽  
pp. 2287-2302 ◽  
Author(s):  
Yusuke Toyoda ◽  
Mitsuhiro Yanagida
Keyword(s):  
Topoisomerase Ii ◽  
Dependent Manner ◽  
Mitotic Progression ◽  
Dna Topoisomerase ◽  
Direct Observations ◽  
Anaphase Onset ◽  
Sister Chromatids ◽  
Chromatid Cohesion ◽  
Topo Ii ◽  
Kinetochore Function

Cohesin maintains sister chromatid cohesion until its Rad21/Scc1/Mcd1 is cleaved by separase during anaphase. DNA topoisomerase II (topo II) maintains the proper topology of chromatid DNAs and is essential for chromosome segregation. Here we report direct observations of mitotic progression in individual HeLa cells after functional disruptions of hRad21, NIPBL, a loading factor for hRad21, and topo II α,β by RNAi and a topo II inhibitor, ICRF-193. Mitosis is delayed in a Mad2-dependent manner after disruption of either or both cohesin and topo II. In hRad21 depletion, interphase pericentric architecture becomes aberrant, and anaphase is virtually permanently delayed as preseparated chromosomes are misaligned on the metaphase spindle. Topo II disruption perturbs centromere organization leading to intense Bub1, but no Mad2, on kinetochores and sustains a Mad2-dependent delay in anaphase onset with persisting securin. Thus topo II impinges upon centromere/kinetochore function. Disruption of topo II by RNAi or ICRF-193 overrides the mitotic delay induced by cohesin depletion: sister centromeres are aligned and anaphase spindle movements occur. The ensuing accumulation of catenations in preseparated sister chromatids may overcome the reduced tension arising from cohesin depletion, causing the override. Cohesin and topo II have distinct, yet coordinated functions in metaphase alignment.

A functional 125-kDa core polypeptide of fission yeast DNA topoisomerase II

1991 ◽  
Vol 11 (12) ◽  
pp. 6093-6102
Author(s):  
K Shiozaki ◽  
M Yanagida
Keyword(s):  
Amino Acids ◽  
Fission Yeast ◽  
Topoisomerase Ii ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Limited Proteolysis ◽  
Dna Topoisomerase Ii ◽  
Dna Topoisomerase ◽  
The Core ◽  
Topo Ii

We purified fission yeast DNA topoisomerase II (topo II) to apparent homogeneity. It consists of a single 165-kDa polypeptide in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and, upon treatment with a bifunctional reagent, doubles its molecular weight. Limited proteolysis of intact topo II by papain produces a 125-kDa core, which lacks the N-terminal 75 and the C-terminal approximately 260 amino acids but still contains regions similar to those of bacterial or phage T4 topo II subunits. The core retains relaxing and unknotting activities. Further digestion inactivates the core, cleaving it at the middle of the GyrB-like domain and at the beginning of the GyrA-like domain. Therefore, papain appears to cleave spatially distinct subdomains of topo II. We made top2 mutant genes deleted of the C-terminal 286 or N-terminal 74 amino acids, which can substitute for the wild-type top2+ gene in mitosis and meiosis. However, a mutant containing deletions of both termini cannot rescue the top2 null mutant, despite the fact that the product is enzymatically active. Therefore, the top2 product of the doubly truncated gene may not fulfill all of the in vivo requirements for top2+ function.

scholarly journals Eukaryotic core histone diversification in light of the histone doublet and DNA topo II genes of Marseilleviridae

2015 ◽  
Author(s):  
Albert J Erives
Keyword(s):  
Topoisomerase Ii ◽  
Domain Architecture ◽  
Histone Variants ◽  
Core Histone ◽  
Histone Fold ◽  
The Core ◽  
Core Histones ◽  
Topo Ii ◽  
Phylogenomic Analyses ◽  
Linear Chromosomes

While eukaryotic and archaean genomes encode the histone fold domain, only eukaryotes encode the core histones H2A, H2B, H3, and H4. Core histones assemble into a hetero-octamer rather than the homo-tetramer of Archaea. Thus it was unexpected that core histone “doublets” were identified in the cytoplasmic replication factories of the Marseilleviridae (MV), one family of Nucleo-Cytoplasmic Large DNA Viruses (NCLDV). Here we analyze the core histone doublet genes from all known Marseilleviridae genomes and show that they encode obligate H2B-H2A and H4-H3 dimers of likely proto-eukaryotic origin. Each MV core histone moiety forms a sister clade to a eukaryotic core histone clade inclusive of canonical core histone paralogs, suggesting that MV core histone moieties diverged prior to eukaryotic neofunctionalizations associated with paired linear chromosomes and variant histone octamer assembly. We also show that all MV genomes encode a eukaryote-like DNA topoisomerase II enzyme that forms a clade that is sister to the eukaryotic clade. As DNA topo II influences histone deposition and chromatin compaction and is the second most abundant nuclear protein after histones, we suggest MV genes underlie a proto-chromatinized replisome that diverged prior to diversification of eukaryotic core histone variants. Thus, combined domain architecture and phylogenomic analyses suggest that a primitive origin for MV chromatin genes is a more parsimonious explanation than horizontal gene transfers + gene fusions + long-branch attraction constrained to each core histone clade. These results imply that core histones were utilized ancestrally in viral DNA compaction, protection from host endonucleases, and/or other unknown processes associated with NCLDV-like progenitors.

A Bird in the Hand Isn’t Good for Long

2018 ◽  
Vol 65 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Stefan Scherbaum ◽  
Simon Frisch ◽  
Maja Dshemuchadse
Keyword(s):  
Decision Making ◽  
Cognitive Control ◽  
The Other ◽  
Decision Task ◽  
Short Term ◽  
Additional Time ◽  
Control Processes ◽  
Folk Wisdom ◽  
Study Participants ◽  
Insight Into

Abstract. Folk wisdom tells us that additional time to make a decision helps us to refrain from the first impulse to take the bird in the hand. However, the question why the time to decide plays an important role is still unanswered. Here we distinguish two explanations, one based on a bias in value accumulation that has to be overcome with time, the other based on cognitive control processes that need time to set in. In an intertemporal decision task, we use mouse tracking to study participants’ responses to options’ values and delays which were presented sequentially. We find that the information about options’ delays does indeed lead to an immediate bias that is controlled afterwards, matching the prediction of control processes needed to counter initial impulses. Hence, by using a dynamic measure, we provide insight into the processes underlying short-term oriented choices in intertemporal decision making.

Will Love Tear Us Apart: Adapting the Lyrical to the Ludic

CounterText ◽  
2016 ◽  
Vol 2 (2) ◽  
pp. 217-235
Author(s):  
Gordon Calleja
Keyword(s):  
Design Process ◽  
Game Design ◽  
Digital Games ◽  
Design Decisions ◽  
The Core ◽  
Lyrical Poetry ◽  
Insight Into ◽  
Made In

This paper gives an insight into the design process of a game adaptation of Joy Division's Love Will Tear Us Apart (1980). It outlines the challenges faced in attempting to reconcile the diverging qualities of lyrical poetry and digital games. In so doing, the paper examines the design decisions made in every segment of the game with a particular focus on the tension between the core concerns of the lyrical work being adapted and established tenets of game design.

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