TOP2B: The First Thirty Years

Austin, Caroline A.; Lee, Ka C.; Swan, Rebecca; Khazeem, Mushtaq M; Manville, Catriona; Cridland, Peter; Treumann, Achim; Porter, Andrew C.G.; Morris, Nicholas J.; Cowell, Ian G.

doi:10.3390/ijms19092765

Cited by 87 publications

(97 citation statements)

References 152 publications

(198 reference statements)

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“…The major contribution of TOP2A protein in PDS-dependent induced DNA breaks appears slightly surprising as a major role on transcription has been credited to TOP2B isoform (20,26,27,70). In human cells, TOP2A is highly expressed in proliferating cells, and further upregulated during S and G2 phases where it plays an essential role during replication and chromosome segregation (20,26,45,46).…”

Section: Discussionmentioning

confidence: 99%

Transcription-associated topoisomerase activities control DNA-breaks production by G-quadruplex ligands

Pipier

Bossaert

Riou

et al. 2020

Preprint

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G-quadruplexes (G4), non-canonical DNA structures, are involved in several essential processes. Stabilization of G4 structures by small compounds (G4 ligands) affects almost all DNA transactions, including telomere maintenance and genomic stability. Here, thanks to a powerful and unbiased genetic approach, we identify topoisomerase 2-alpha (TOP2A) as the main effector of cell cytotoxicity induced by CX5461, a G4 ligand currently undergoing phase I/II clinical trials. This approach also allowed to identify new point mutations affecting TOP2A activity without compromising cell viability. Moreover, based on cross-resistance studies and siRNA-based protein depletion we report that TOP2A plays a major role in cell cytotoxicity induced by two unrelated clastogenic G4 ligands, CX5461 and pyridostatin (PDS). We also report that cytotoxic effects induced by both compounds are associated with topoisomerase 2mediated DNA breaks production. Finally, we show that TOP2-mediated DNA breaks production is strongly associated with RNA Pol II-dependent transcription and is countered by topoisomerase 1 (TOP1). Altogether our results indicate that clastogenic G4 ligands act as DNA structure-driven TOP2-poisons at transcribed regions bearing G-quadruplex structures.

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Section: Discussionmentioning

confidence: 99%

Transcription-associated topoisomerase activities control DNA-breaks production by G-quadruplex ligands

Pipier

Bossaert

Riou

et al. 2020

Preprint

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“…demonstrated that CC-seq maps CCs of both human TOP2α and TOP2β-452 proteins that are conserved amongst all vertebrates and whose functional differences453 remain a subject of interest within the field(Austin et al, 2018). Given the essential 454 requirement for TOP2α during mitosis(Akimitsu et al, 2003), and the apparent inability of 455 TOP2β to compensate for its loss(Grue et al, 1998), it will be particularly interesting to456 determine the genomic distribution of TOP2α/TOP2β activities throughout the cell cycle,457 and to relate this to 3D chromatin conformation measured by Hi-C. Whilst not essential for458 cell proliferation, TOP2β plays an important role in promoting transcriptional programmes 459 associated with neuronal development (Tiwari et al, 2012), and this function cannot be 460 supported by TOP2α.…”

mentioning

confidence: 99%

A nucleotide resolution map of Top2-linked DNA breaks in the yeast and human genome

Gittens

Johnson

Allison

et al. 2019

Preprint

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12DNA topoisomerases are required to resolve DNA topological stress. Despite this essential 13 role, abortive topoisomerase activity generates aberrant protein-linked DNA breaks, 14 jeopardising genome stability. Here, to understand the genomic distribution and 15 mechanisms underpinning topoisomerase-induced DNA breaks, we map Top2 DNA 16 cleavage with strand-specific nucleotide resolution across the S. cerevisiae and human 17 genomes-and use the meiotic Spo11 protein to validate the broad applicability of this 18 method to explore the role of diverse topoisomerase family members. Our data 19 characterises Mre11-dependent repair in yeast, and defines two strikingly different fractions 20 of Top2 activity in humans: tightly localised CTCF-proximal and broadly distributed 21 transcription-proximal. Moreover, the nucleotide resolution accuracy of our assay reveals 22 the influence primary DNA sequence has upon Top2 cleavage-for the first time 23 distinguishing canonical DNA double-strand breaks (DSBs) from a major population of DNA 24 single-strand breaks (SSBs) induced by etoposide (VP16) in vivo. 25 26 27 101 1995; Keeney et al., 1997), an orthologue of archaeal Topoisomerase VI (Bergerat et al., 102 1997). We first verified this enrichment principle using meiotic sae2Δ cells, in which Spo11-103 linked DSBs are known to accumulate at defined loci due to abrogation of the nucleolytic 104 pathway that releases Spo11 (Keeney and Kleckner, 1995; Neale et al., 2005). To 105 demonstrate specific enrichment of protein-linked molecules, total genomic DNA from 106 Gittens et al. 2019 meiotic S. cerevisiae cells was isolated in the absence of proteolysis, digested with PstI 107 restriction enzyme, and isolated on glass-fibre spin columns (Figure 1A, Methods). We 108 used eluted material to assay a known Spo11-DSB hotspot by Southern blotting (Figure 109 1B). While DSB fragments are a minor fraction of input material (~10% of total), and were 110 absent in wash fractions, DSBs accounted for >99% of total eluted material, indicating 111 ~1000-fold enrichment relative to non-protein-linked DNA (Figure 1B). 112 113 CC-seq maps known Spo11-DSB hotspots genome-wide with high reproducibility 114 To generate a genome-wide map of Spo11-DSBs, genomic DNA from meiotic sae2∆ cells 115 was sonicated to <400 bp in length, enriched upon the silica column, eluted, and ligated to 116 DNA adapters in a two-step procedure that utilised the known phosphotyrosyl-unlinking 117 activity of mammalian TDP2 to uncap the Spo11-bound end ('CC-seq'; Figure 1A / 118 Methods) (Cortes Ledesma et al., 2009; Johnson et al., 2019). Libraries were paired-end 119 sequenced and mapped to the S. cerevisiae reference genome (Table S1) alongside reads 120 from a previous mapping technique ('Spo11-oligo-seq') that relies on the isolation of 121 Spo11-linked oligonucleotides generated in wild-type cells during DSB repair (Pan et al., 122 2011). CC-seq revealed sharp, localised peaks ('hotspots') in SPO11+ cells (Figure 1C, 123 middle) that visually (Figu...

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“…Subsequently, glucocorticoid receptor was also reported to transactivate genes via TOP2β-produced DSBs [73]. Additionally, TOP2β is expressed in differentiation cells and neurons [74,75]; the expression of long-transcripts linked to autism is facilitated by TOP2β [76]. While it is indeed intriguing for an essential role of DSBs at least in a subset of gene transcription, it is clear that DSBs need to be effectively repaired regardless of their sources of generation owning to their toxic impact on genome stability [77].…”

Section: Link Of Dsb With Admentioning

confidence: 99%

Contributions of DNA Damage to Alzheimer’s Disease

Lin

Kapoor

et al. 2020

IJMS

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Alzheimer's disease (AD) is the most common type of neurodegenerative disease. Its typical pathology consists of extracellular amyloid-β (Aβ) plaques and intracellular tau neurofibrillary tangles. Mutations in the APP, PSEN1, and PSEN2 genes increase Aβ production and aggregation, and thus cause early onset or familial AD. Even with this strong genetic evidence, recent studies support AD to result from complex etiological alterations. Among them, aging is the strongest risk factor for the vast majority of AD cases: Sporadic late onset AD (LOAD). Accumulation of DNA damage is a well-established aging factor. In this regard, a large amount of evidence reveals DNA damage as a critical pathological cause of AD. Clinically, DNA damage is accumulated in brains of AD patients. Genetically, defects in DNA damage repair resulted from mutations in the BRAC1 and other DNA damage repair genes occur in AD brain and facilitate the pathogenesis. Abnormalities in DNA damage repair can be used as diagnostic biomarkers for AD. In this review, we discuss the association, the causative potential, and the biomarker values of DNA damage in AD pathogenesis.Int. J. Mol. Sci. 2020, 21, 1666 2 of 26 amyloid (senile) plaques in AD brain [9][10][11]. Furthermore, CDK5 activities affect DNA damage response [12], supporting a linkage of DNA damage with AD [13,14].Aβ peptides are directly produced by sequential cleavages of APP by βand γ-secretase; the proteolytic c-terminal fragment of APP (CTFβ) of β-secretase is cleaved within the cell membrane by γ-secretase to generate neurotoxic Aβ peptides with length ranging from 38-43 residues [15][16][17][18][19]. The 40 residue Aβ peptide (Aβ 1-40 ) is the major product, accounting for more than 50% of Aβ peptides [9,17]. Although the Aβ 1-42 peptide consists of less than 10% of Aβ peptides [16,17], it is more neurotoxic and associates with a higher risk of AD because of its propensity of aggregation [9]. The importance of Aβ in AD pathogenesis is illustrated by mutations of APP, PSEN1, and PREN2 genes in familial AD with the latter two encoding the presenilin 1 and presenilin 2 subunit of γ-secretase. Individuals with these mutations develop early onset dementia in an autosomal-dominant manner [20]; the typical onset starts between 30 and 50 years of age in PSEN1 mutant carriers with some being affected at in their 20s [20,21]. γ-secretase with mutant presenilin 1 or presenilin 2 subunit favors Aβ 1-42 production [16,17]. These genetic observations led to formation of the amyloid cascade hypothesis, in which abnormal Aβ drives AD pathogenesis via regulating other pathological events including tau pathology [22][23][24][25][26][27]. This hypothesis is supported by the similar pathological features between familial AD and sporadic late onset AD (LOAD) [20]. Although familial AD constitutes less than 1% of AD cases [28,29], the hypothesis has been widely accepted to guide research in advancing the understanding of both familial AD and LOAD in the past two decades [30,31].Nonetheless, it is becoming in...

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TOP2B: The First Thirty Years

Cited by 87 publications

References 152 publications

Transcription-associated topoisomerase activities control DNA-breaks production by G-quadruplex ligands

Transcription-associated topoisomerase activities control DNA-breaks production by G-quadruplex ligands

A nucleotide resolution map of Top2-linked DNA breaks in the yeast and human genome

Contributions of DNA Damage to Alzheimer’s Disease

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