Methylated histones on mitotic chromosomes promote topoisomerase IIα function for high fidelity chromosome segregation

Sundararajan, Sanjana; Park, Hyewon; Johansson, Marnie; Lama, Bunu; Saito‐Fujita, Tomoko; Saitoh, Noriko; Arnaoutov, Alexei; Dasso, Mary; Wang, Zhengqiang; Keifenheim, Daniel; Clarke, Duncan J.; Azuma, Yoshiaki

doi:10.1016/j.isci.2023.106743

Cited by 5 publications

(3 citation statements)

References 42 publications

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“…Chromatin is the natural substrate of eukaryotic topo II in vivo. Although there is some evidence that the C-terminus of topo II can associate with histone proteins 40 , 41 , the catalytic domains of topo II likely interact directly with linker DNA between nucleosomes. Since chromatinization markedly alters the structural and torsional mechanical properties of DNA 21 , 42 , we speculated that the activity of topo II on chromatinized substrates may be significantly different from that on naked DNA.…”

Section: Resultsmentioning

confidence: 99%

Chromatinization modulates topoisomerase II processivity

Lee,

Wu,

Inman

et al. 2023

Nat Commun

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Type IIA topoisomerases are essential DNA processing enzymes that must robustly and reliably relax DNA torsional stress. While cellular processes constantly create varying torsional stress, how this variation impacts type IIA topoisomerase function remains obscure. Using multiple single-molecule approaches, we examined the torsional dependence of eukaryotic topoisomerase II (topo II) activity on naked DNA and chromatin. We observed that topo II is ~50-fold more processive on buckled DNA than previously estimated. We further discovered that topo II relaxes supercoiled DNA prior to plectoneme formation, but with processivity reduced by ~100-fold. This relaxation decreases with diminishing torsion, consistent with topo II capturing transient DNA loops. Topo II retains high processivity on buckled chromatin (~10,000 turns) and becomes highly processive even on chromatin under low torsional stress (~1000 turns), consistent with chromatin’s predisposition to readily form DNA crossings. This work establishes that chromatin is a major stimulant of topo II function.

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Section: Resultsmentioning

confidence: 99%

Chromatinization modulates topoisomerase II processivity

Lee,

Wu,

Inman

et al. 2023

Nat Commun

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“…The discovery of a nucleosome binding region of Topo IIA, the chromatin tether (ChT) domain ( Lane et al, 2013 ), could provide this missing link. Deletion of the ChT results in chromosome segregation errors, the expected phenotype if the checkpoint requires the ChT to efficiently enact Haspin-mediated H3T3 phosphorylation ( Sundararajan et al, 2023 ). It will be important to determine if the ChT is required for the activation of the checkpoint.…”

Section: Engagement Of the Metaphase Topo Iia Checkpoint Is Distinct ...mentioning

confidence: 99%

Cell cycle responses to Topoisomerase II inhibition: Molecular mechanisms and clinical implications

Soliman,

Keifenheim,

Parker

et al. 2023

Journal of Cell Biology

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DNA Topoisomerase IIA (Topo IIA) is an enzyme that alters the topological state of DNA and is essential for the separation of replicated sister chromatids and the integrity of cell division. Topo IIA dysfunction activates cell cycle checkpoints, resulting in arrest in either the G2-phase or metaphase of mitosis, ultimately triggering the abscission checkpoint if non-disjunction persists. These events, which directly or indirectly monitor the activity of Topo IIA, have become of major interest as many cancers have deficiencies in Topoisomerase checkpoints, leading to genome instability. Recent studies into how cells sense Topo IIA dysfunction and respond by regulating cell cycle progression demonstrate that the Topo IIA G2 checkpoint is distinct from the G2-DNA damage checkpoint. Likewise, in mitosis, the metaphase Topo IIA checkpoint is separate from the spindle assembly checkpoint. Here, we integrate mechanistic knowledge of Topo IIA checkpoints with the current understanding of how cells regulate progression through the cell cycle to accomplish faithful genome transmission and discuss the opportunities this offers for therapy.

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“…Chromatin is the natural substrate of eukaryotic topo II in vivo. Although there is some evidence that the C-terminus of topo II can associate with histone proteins 36,37 , the catalytic domains of topo II likely interact directly with the linker DNA that connects nucleosomes. Since chromatinization markedly alters the structural and torsional mechanical properties of DNA 27 , we speculate that the activity of topo II on chromatinized substrates may be significantly different from that on wholly naked DNA.…”

Section: Chromatinization Enhances Topo II Processivitymentioning

confidence: 99%

Chromatinization Modulates Topoisomerase II Processivity

Lee,

Wu,

Inman

et al. 2023

Preprint

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Type IIA topoisomerases are essential DNA processing enzymes that must robustly and reliably relax DNA torsional stressin vivo. While cellular processes constantly create different degrees of torsional stress, how this stress feeds back to control type IIA topoisomerase function remains obscure. Using a suite of single-molecule approaches, we examined the torsional impact on supercoiling relaxation of both naked DNA and chromatin by eukaryotic topoisomerase II (topo II). We observed that topo II was at least ∼ 50-fold more processive on plectonemic DNA than previously estimated, capable of relaxing > 6000 turns. We further discovered that topo II could relax supercoiled DNA prior to plectoneme formation, but with a ∼100-fold reduction in processivity; strikingly, the relaxation rate in this regime decreased with diminishing torsion in a manner consistent with the capture of transient DNA loops by topo II. Chromatinization preserved the high processivity of the enzyme under high torsional stress. Interestingly, topo II was still highly processive (∼ 1000 turns) even under low torsional stress, consistent with the predisposition of chromatin to readily form DNA crossings. This work establishes that chromatin is a major stimulant of topo II function, capable of enhancing function even under low torsional stress.

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Methylated histones on mitotic chromosomes promote topoisomerase IIα function for high fidelity chromosome segregation

Cited by 5 publications

References 42 publications

Chromatinization modulates topoisomerase II processivity

Chromatinization modulates topoisomerase II processivity

Cell cycle responses to Topoisomerase II inhibition: Molecular mechanisms and clinical implications

Chromatinization Modulates Topoisomerase II Processivity

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