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PubMed2025

Comparative Analysis of Somatic and Germline Polymerase Proofreading Deficiencies in Cancer: Molecular and Clinical Implications.

Polymerases ε and δ maintain genome integrity through exonuclease proofreading. Germline and somatic pathogenic variants (PVs) in the exonuclease domain (ED) of POLE and POLD1 impair proofreading, causing hypermutated tumors. Despite shared mutational features that make these tumors highly immunogenic, molecular and clinical distinctions between POLE and POLD1 mutations and between somatic and germline variants remain incompletely understood. We compared the molecular and clinical characteristics of POLE and POLD1 ED PVs (n = 31), assessing their location, pathogenicity, clinical phenotypes, mismatch repair (MMR) status, tumor mutational burden, and signatures. We analyzed 360 proofreading-deficient tumors (source: The Cancer Genome Atlas [TCGA] and Catalogue Of Somatic Mutations In Cancer [COSMIC]) and 70 families (249 individuals) with polymerase proofreading-associated polyposis. All germline and somatic PVs had high AlphaMissense scores (0.87-1) and clustered within or near Exo motifs. Recurrent, nonfounder germline PVs, POLE L424V and POLD1 S478N, showed low/modest REVEL scores. Somatic variants occurred mainly in endometrial cancers (75% of proofreading-deficient TCGA cancers), whereas colorectal cancer predominated in polymerase proofreading-associated polyposis (56% of carriers). Cancer risks and tumor spectra differed between POLE and POLD1 PV carriers. Aggressive hereditary phenotypes were linked to either specific POLE PVs (eg, S297F, V411L, P436R, M444K, A456P, and S461T) or the co-occurrence of germline ED PVs with germline MMR gene PVs. Distinct hypermutator profiles were confirmed for polymerase ε and polymerase δ proofreading deficiencies via unique mutational signatures (Polymerase ε: SBS10a/b, SBS28; Polymerase δ: SBS10c/d). Tumors with combined proofreading and MMR deficiencies had significantly higher tumor mutational burden and a shift in the associated mutational spectra. Unlike POLE, POLD1 ED PVs exhibited haplosufficiency, typically requiring a somatic second hit (eg, loss of heterozygosity) or MMR deficiency to drive hypermutation. In conclusion, differences between POLE and POLD1 and between somatic and germline mutations influence clinical presentation, mutagenic potential, and reliance on cooperating defects in tumorigenesis. These insights advance the understanding of proofreading-deficient cancers, with implications for diagnostics, genetic counseling, and precision oncology.

Humans↗

PubMed2025

The DNA replication checkpoint limits Okazaki fragment accumulation to protect and restart stalled forks.

Understanding how DNA replication forks stall and restart and how the DNA replication checkpoint prevents irreversible fork collapse in molecular detail are crucial for understanding how cells maintain stable genomes and how they prevent the genetic instability that drives cancer. Here, we describe the reconstitution of fork stalling and restart with purified budding yeast proteins. After nucleotide depletion, leading-strand DNA synthesis quickly stops but CMG helicase continues to unwind, and Okazaki fragments continue to initiate on the lagging strand. Incomplete Okazaki fragments sequester PCNA, RFC, and DNA polymerases δ and ε, which prevents normal DNA synthesis restart and exposes nascent DNA to nuclease attack. The DNA replication checkpoint restrains fork progression, which limits this sequestration, protecting stalled forks from collapse and ensuring restart.

DNA Replication↗

PubMed2026

ChromID: A Protocol for Mapping Protein Chromatin Interactions in Living Cells.

Chromatin modifications regulate genome function by recruiting proteins that control transcription, genome organization, and DNA repair. Identifying the proteins associated with specific chromatin modifications is therefore essential for understanding how these regulatory processes operate. Traditional approaches, including chromatin immunoprecipitation and affinity purification coupled to mass spectrometry, have uncovered many chromatin-associated proteins. However, they often rely on crosslinking and chromatin fragmentation, which can disrupt native chromatin architecture and limit the detection of transient interactions. Here, we describe a proximity-labeling protocol for identifying the chromatin-dependent protein interactome associated with specific chromatin marks, termed ChromID. ChromID uses engineered chromatin readers (eCRs) fused to a promiscuous biotin ligase, which labels proteins in the immediate vicinity of the targeted chromatin mark. The protocol includes in vivo biotin labeling, nuclear extract preparation, streptavidin-based enrichment, and tryptic digestion for downstream LC-MS/MS analysis. The protocol has been validated across multiple cell types and chromatin contexts and can be extended to other chromatin-associated proteins, providing a versatile approach to profile chromatin-associated proteomes within their native cellular environment. Key features • Maps proteins associated with different chromatin modifications in living cells using engineered chromatin readers fused to TurboID, BASU, or other promiscuous biotin ligases. • Preserves native chromatin organization and captures transient chromatin-associated interactions that are often lost during conventional affinity purification workflows. • Validated across multiple chromatin contexts, including histone modifications, DNA methylation, transcription factors, RNA polymerase II, and DNA damage-associated chromatin states. • Applicable to diverse cell types and organisms and adaptable to other chromatin-associated proteins, including transcription factors and chromatin regulators.

Biotin proximity labeling↗

PubMed2026

The clinical landscape of POLE-mutant colorectal cancer: a retrospective analysis of real-world outcome.

BACKGROUND: Pathogenic mutations in the POLE gene disrupt its proofreading function during DNA replication, causing an accumulation of erroneous nucleotide incorporations. This defect leads to a significantly elevated tumor mutation burden (TMB) and increased generation of tumor neoantigens. These molecular characteristics suggest a potential association between POLE-mutant tumors and distinct prognostic outcomes in colorectal cancer (CRC); however, clinical evidence supporting this correlation remains limited. METHODS: We retrospectively collected a cohort of CRC patients harboring pathogenic POLE mutations. Comparative analyses were performed between POLE-mutant and POLE wild-type CRCs regarding their clinical characteristics, prognostic outcomes, and genomic profiles. Additionally, we evaluated the response to immunotherapy in metastatic POLE-mutant CRC cases. RESULTS: Among 35,108 CRC patients, pathogenic POLE mutations were identified in 261 individuals, accounting for 0.74% of the cohort. The median age at diagnosis for POLE-mutant patients was 48 years, with a male predominance (74.4%) and a substantial proportion (50.4%) of tumors localized in the right-sided colon. All patients with pathogenic POLE mutations exhibited hypermutated phenotypes, characterized by a median TMB of 235.26 mutations per megabase (range: 71.20-719.00 mutations/Mb). In stage II CRC, POLE mutations were significantly associated with a reduced risk of recurrence (hazard ratio [HR] 0.344, 95% confidence interval [CI] 0.157-0.754, p = 0.008) when compared to POLE wild-type, microsatellite stable CRC patients. However, this association was not evident in stage III patients (HR 1.004, 95% CI 0.490-2.057, p = 0.992). Importantly, the incorporation of immune checkpoint inhibitors in first-line treatment regimens significantly improved progression-free survival (HR = 0.247, 95% CI 0.117-0.552, p = 0.0002) and overall survival (HR = 0.317, 95% CI 0.103-1.143, p = 0.0832) in metastatic CRC patients with pathogenic POLE mutations. CONCLUSIONS: Pathogenic POLE-mutant CRC constitutes a relatively rare, yet clinically important, subtype. These cancers exhibit distinct clinicopathological and genomic features. Our results indicate that mutations in the POLE gene may serve as a valuable prognostic marker and a potential indicator of benefit to immunotherapy in CRC, offering promising avenues for personalized treatment strategies.

Humans↗

PubMed2026

Estrogen Receptor, GATA-3, TTF-1, and KRAS in Endometrial Carcinoma of No Specific Molecular Profile: Prognostic or Diagnostic Markers?

Endometrial carcinoma with no specific molecular profile (NSMP) is a clinicopathologically heterogeneous group of diseases with an overall intermediate prognosis. Prognostic refinement is needed for better personalized treatment. The updated European Society of Gynecological Oncology-European Society for Radiotherapy and Oncology-European Society of Pathology guidelines for endometrial carcinoma stratify NSMP according to histotype and estrogen receptor (ER) status. ER (with other ancillary markers) also helps differentiate histotypes of endometrial carcinoma. This study describes clinicopathological characteristics of ER-positive and -negative-NSMP endometrial carcinoma. Furthermore, we investigate the prognostic and diagnostic significance of ER, GATA3, TTF1, and KRAS in a large and relatively unselected NSMP carcinoma cohort. POLE sequencing results and immunohistochemistry for p53, mismatch repair proteins, and ER were available for 930 samples of endometrial carcinoma. Within NSMP cases (n = 377), 22 samples presented ER staining in <1% of the carcinoma cells, 5 cases in 1% to 9%, and 350 cases in ≥10%. ER expression ≥10% predicted an excellent outcome (comparable with POLE-mutated cases) in univariable analysis, where ER negativity (<10%) was associated with a poor outcome (comparable with p53 abnormal cases). Most ER-positive NSMP cases were low-grade endometrioid carcinomas, whereas most ER-negative NSMP cases were nonendometrioid or high-grade endometrioid carcinomas. In addition to high-risk histotype, ER negativity was associated with various other clinicopathological risk factors. In multivariable analysis adjusting for histotype and other risk factors, ER did not independently predict disease progression (P = .814). No disease-related deaths were observed in the rare (n = 3) patients with ER-negative-low-grade endometrioid carcinoma. GATA3/TTF1 positivity and KRAS mutation were discovered not only in mesonephric-like carcinoma but also in endometrioid carcinoma. No prognostic relevance was found for these markers. In conclusion, the different prognosis of ER-positive vs ER-negative-NSMP endometrial carcinoma is not attributable to ER status itself but rather to its strong correlation with histotype and other clinicopathological risk factors. Limited specificity of GATA3, TTF1, and KRAS warrants caution in their use as diagnostic markers of mesonephric-like carcinoma.

Humans↗

PubMed2026

Deficiency in POLE Exonuclease Causes Synthetic Lethality in Highly Aneuploid Cancer Cells.

UNLABELLED: Aneuploidy is a hallmark of cancer and is associated with drug resistance and poor clinical outcomes across diverse cancer types. However, no therapies have been clinically established to target highly aneuploid tumors. By analyzing nearly half a million tumor samples subjected to comprehensive genomic profiling, we identified a striking mutual exclusivity between POLE exonuclease domain mutations and high aneuploidy burden. This observation was independently validated using data from The Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia (CCLE). Probabilistic modeling revealed that the elevated quantity and unique spectrum of mutations induced by POLE exonuclease deficiency increase the likelihood of inactivating essential genes on chromosome arms harboring losses, leading to a synthetic lethal phenotype in highly aneuploid cells. Functional experiments demonstrated that POLE exonuclease activity is essential for the viability of highly aneuploid cancer cell lines but dispensable in diploid cells. These findings suggest that selective inhibition of POLE exonuclease activity may represent a promising therapeutic strategy for targeting highly aneuploid tumors. SIGNIFICANCE: An integrated approach using large-scale genomic analyses, probabilistic modeling and functional validation identified POLE exonuclease as a potential synthetic lethal target to overcome cancer aneuploidy.

Humans↗

PubMed2026

Structural Features of DNA in TATA-Containing and TATA-Less Core Promoters of RNA Polymerase II Differ.

Nucleotide motifs in the core promoters of eukaryotic protein-coding genes transcribed by RNA polymerase II (Pol II) play an important role in the transcription process. We analyzed the role of an octanucleotide located in the TATA box position. Depending on whether this octanucleotide can form a complex with the TATA-binding protein (TBP), the promoter is classified as either TATA-containing or TATA-less. We analyzed the differences in the primary and spatial structures, as well as their dynamics, in TATA-containing and TATA-less promoters of mammals and plants. We divided the complete promoter sets of six organisms (H. sapiens, M. musculus, C. familiaris, A. thaliana, Z. mays, and H. vulgare) from the EPDnew database into TATA-containing and TATA-less fractions. The sizes of the TATA-containing promoter fractions are significantly smaller than those of the TATA-less fractions in all studied organisms, except in A. thaliana, where the sizes of both fractions are approximately equal. We characterized promoter architecture using variation profiles of various base-pair step parameters, minor-groove width, and the conformational dynamics of native DNA. The architectures of TATA-containing and TATA-less promoters differ significantly. The possible mechanistic influence of DNA structural features on the formation of the pre-initiation complex (PIC) in both types of promoters is discussed.

Promoter Regions, Genetic↗

PubMed2024

Cell-type-specific loops linked to RNA polymerase II elongation in human neural differentiation.

DNA is folded into higher-order structures that shape and are shaped by genome function. The role of long-range loops in the establishment of new gene expression patterns during cell fate transitions remains poorly understood. Here, we investigate the link between cell-specific loops and RNA polymerase II (RNA Pol II) during neural lineage commitment. We find thousands of loops decommissioned or gained de novo upon differentiation of human induced pluripotent stem cells (hiPSCs) to neural progenitor cells (NPCs) and post-mitotic neurons. During hiPSC-to-NPC and NPC-to-neuron transitions, genes changing from RNA Pol II initiation to elongation are >4-fold more likely to anchor cell-specific loops than repressed genes. Elongated genes exhibit significant mRNA upregulation when connected in cell-specific promoter-enhancer loops but not invariant promoter-enhancer loops or promoter-promoter loops or when unlooped. Genes transitioning from repression to RNA Pol II initiation exhibit a slight mRNA increase independent of loop status. Our data link cell-specific loops and robust RNA Pol II-mediated elongation during neural cell fate transitions.

Humans↗

PubMed2023

Cell type-specific loops linked to RNA polymerase II elongation in human neural differentiation.

DNA is folded into higher-order structures that shape and are shaped by genome function. The role for long-range loops in the establishment of new gene expression patterns during cell fate transitions remains poorly understood. Here, we investigate the link between cell-specific loops and RNA polymerase II (RNAPolII) during neural lineage commitment. We find thousands of loops decommissioned or gained de novo upon differentiation of human induced pluripotent stem cells (hiPSCs) to neural progenitors (NPCs) and post-mitotic neurons. During hiPSC-to-NPC and NPC-to-neuron transitions, genes changing from RNAPolII initiation to elongation are >4-fold more likely to anchor cell-specific loops than repressed genes. Elongated genes exhibit significant mRNA upregulation when connected in cell-specific promoter-enhancer loops but not invariant promoter-enhancer loops, promoter-promoter loops, or unlooped. Genes transitioning from repression to RNAPolII initiation exhibit slight mRNA increase independent of loop status. Our data link cell-specific loops and robust RNAPolII-mediated elongation during neural cell fate transitions.

Preprint↗

PubMed2024

DNA lesion bypass and the stochastic dynamics of transcription-coupled repair.

DNA base damage is a major source of oncogenic mutations and disruption to gene expression. The stalling of RNA polymerase II (RNAP) at sites of DNA damage and the subsequent triggering of repair processes have major roles in shaping the genome-wide distribution of mutations, clearing barriers to transcription, and minimizing the production of miscoded gene products. Despite its importance for genetic integrity, key mechanistic features of this transcription-coupled repair (TCR) process are controversial or unknown. Here, we exploited a well-powered in vivo mammalian model system to explore the mechanistic properties and parameters of TCR for alkylation damage at fine spatial resolution and with discrimination of the damaged DNA strand. For rigorous interpretation, a generalizable mathematical model of DNA damage and TCR was developed. Fitting experimental data to the model and simulation revealed that RNA polymerases frequently bypass lesions without triggering repair, indicating that small alkylation adducts are unlikely to be an efficient barrier to gene expression. Following a burst of damage, the efficiency of transcription-coupled repair gradually decays through gene bodies with implications for the occurrence and accurate inference of driver mutations in cancer. The reinitation of transcription from the repair site is not a general feature of transcription-coupled repair, and the observed data is consistent with reinitiation never taking place. Collectively, these results reveal how the directional but stochastic activity of TCR shapes the distribution of mutations following DNA damage.

Animals↗

PubMed2025

RNA Pol II inhibition activates cell death independently from the loss of transcription.

RNA Pol II-mediated transcription is essential for eukaryotic life. Although loss of transcription is thought to be universally lethal, the associated mechanisms promoting cell death are not yet known. Here, we show that death following the loss of RNA Pol II activity does not result from dysregulated gene expression. Instead, it occurs in response to loss of the hypophosphorylated form of Rbp1 (also called RNA Pol IIA). Loss of RNA Pol IIA exclusively activates apoptosis, and expression of a transcriptionally inactive version of Rpb1 rescues cell viability. Using functional genomics, we identify the mechanisms driving lethality following the loss of RNA Pol IIA, which we call the Pol II degradation-dependent apoptotic response (PDAR). Using the genetic dependencies of PDAR, we identify clinically used drugs that owe their lethality to a PDAR-dependent mechanism. Our findings unveil an apoptotic signaling response that contributes to the efficacy of a wide array of anti-cancer therapies.

RNA Polymerase II↗

PubMed2025

Donor transcription suppresses D-loops in cis and promotes genome stability.

DNA is a substrate for competing protein-mediated activities. Whether and how transcription and the synaptic steps of recombination collide or are coordinated has not been investigated. Here, using a controlled break induction system and physical detection of D-loop DNA joint molecules in S. cerevisiae, we show that donor transcription by RNA polymerase II strongly and acutely suppresses D-loops in cis. The extent of this suppression depends on the orientation of transcription, suggesting the preferential usage of one end for the repair of DNA break in transcribed regions. Transcription-mediated D-loop suppression does not rely on endogenous transcription factors, the RNA product, or RNA:DNA hybrids. It is independent of, and can be more potent than the conserved trans D-loop-disruption factors Sgs1-Top3-Rmi1BLM-TOPO3α-RMI1/2, Mph1FANCM, and Srs2. This transcription-mediated control promotes genome maintenance by inhibiting ectopic recombination and multi-invasion-induced rearrangements, while authorizing allelic inter-homolog repair. These findings reveal the prioritization between two universal DNA-dependent processes and its role in promoting genome stability.

Genomic Instability↗

PubMed2026

RAD54L coordinates the nucleolar DNA damage response to maintain rDNA stability.

The nucleolus is organized around actively transcribed ribosomal RNA genes (rDNA), where high RNA polymerase I (Pol I) activity creates intrinsic susceptibility to replication stress and DNA damage. Here, we identify the DNA translocase RAD54L as a critical regulator of the nucleolar DNA damage response (nDDR) to rDNA double-strand breaks (DSBs) and replication stress. We show that RAD54L localizes to the nucleolus under basal conditions and is recruited to nucleolar caps following CRISPR-Cas9-induced rDNA-DSBs to promote repair. RAD54L loss results in persistent RAD51 foci, increased nucleolar γH2AX, and micronuclei formation, indicating defective resolution of rDNA lesions and genome instability. Under baseline conditions and replication stress induced by the Pol I transcription inhibitor CX-5461, RAD54L limits the accumulation of ssDNA and coordinates nDDR signaling. We further show that rDNA-DSBs induce RNA polymerase II-dependent RNA-DNA hybrids (R-loops) at intergenic rDNA regions, which facilitate nucleolar reorganization and cap formation and repair factor recruitment. Together, these findings establish RAD54L as a key regulator that coordinates replication stress response and rDNA repair, maintaining rDNA stability and genome integrity.

DNA, Ribosomal↗

PubMed2004

Dlx3 transcriptional regulation of osteoblast differentiation: temporal recruitment of Msx2, Dlx3, and Dlx5 homeodomain proteins to chromatin of the osteocalcin gene.

Genetic studies show that Msx2 and Dlx5 homeodomain (HD) proteins support skeletal development, but null mutation of the closely related Dlx3 gene results in early embryonic lethality. Here we find that expression of Dlx3 in the mouse embryo is associated with new bone formation and regulation of osteoblast differentiation. Dlx3 is expressed in osteoblasts, and overexpression of Dlx3 in osteoprogenitor cells promotes, while specific knock-down of Dlx3 by RNA interference inhibits, induction of osteogenic markers. We characterized gene regulation by Dlx3 in relation to that of Msx2 and Dlx5 during osteoblast differentiation. Chromatin immunoprecipitation assays revealed a molecular switch in HD protein association with the bone-specific osteocalcin (OC) gene. The transcriptionally repressed OC gene was occupied by Msx2 in proliferating osteoblasts, while Dlx3, Dlx5, and Runx2 were recruited postproliferatively to initiate transcription. Dlx5 occupancy increased over Dlx3 in mature osteoblasts at the mineralization stage of differentiation, coincident with increased RNA polymerase II occupancy. Dlx3 protein-DNA interactions stimulated OC promoter activity, while Dlx3-Runx2 protein-protein interaction reduced Runx2-mediated transcription. Deletion analysis showed that the Dlx3 interacting domain of Runx2 is from amino acids 376 to 432, which also include the transcriptionally active subnuclear targeting sequence (376 to 432). Thus, we provide cellular and molecular evidence for Dlx3 in regulating osteoprogenitor cell differentiation and for both positive and negative regulation of gene transcription. We propose that multiple HD proteins in osteoblasts constitute a regulatory network that mediates development of the bone phenotype through the sequential association of distinct HD proteins with promoter regulatory elements.

Amino Acid Sequence↗

PubMed2024

Multiple Forms and Functions of Premature Termination by RNA Polymerase II.

Eukaryotic genomes are widely transcribed by RNA polymerase II (pol II) both within genes and in intergenic regions. POL II elongation complexes comprising the polymerase, the DNA template and nascent RNA transcript must be extremely processive in order to transcribe the longest genes which are over 1 megabase long and take many hours to traverse. Dedicated termination mechanisms are required to disrupt these highly stable complexes. Transcription termination occurs not only at the 3' ends of genes once a full length transcript has been made, but also within genes and in promiscuously transcribed intergenic regions. Termination at these latter positions is termed "premature" because it is not triggered in response to a specific signal that marks the 3' end of a gene, like a polyA site. One purpose of premature termination is to remove polymerases from intergenic regions where they are "not wanted" because they may interfere with transcription of overlapping genes or the progress of replication forks. Premature termination has recently been appreciated to occur at surprisingly high rates within genes where it is speculated to serve regulatory or quality control functions. In this review I summarize current understanding of the different mechanisms of premature termination and its potential functions.

RNA Polymerase II↗

PubMed2024

Pause Patrol: Negative Elongation Factor's Role in Promoter-Proximal Pausing and Beyond.

RNA polymerase (Pol) II is highly regulated to ensure appropriate gene expression. Early transcription elongation is associated with transient pausing of RNA Pol II in the promoter-proximal region. In multicellular organisms, this pausing is stabilized by the association of transcription elongation factors DRB-sensitivity inducing factor (DSIF) and Negative Elongation Factor (NELF). DSIF is a broadly conserved transcription elongation factor whereas NELF is mostly restricted to the metazoan lineage. Mounting evidence suggests that NELF association with RNA Pol II serves as checkpoint for either release into rapid and productive transcription elongation or premature termination at promoter-proximal pause sites. Here we summarize NELF's roles in promoter-proximal pausing, transcription termination, DNA repair, and signaling based on decades of cell biological, biochemical, and structural work and describe areas for future research.

Promoter Regions, Genetic↗

PubMed2025

Crosstalk between chromatin state and ATM signalling in DNA damage-induced transcription stress.

The DNA Damage Response (DDR) is a highly regulated process that safeguards genomic integrity against DNA lesions. Increasing evidence supports a reciprocal relationship between damaged chromatin architecture and the signalling pathways that coordinate the DDR. However, the mechanisms underlying this interplay in response to transcription-blocking DNA lesions remain largely unexplored. Here, we show that stalling of RNA polymerase II (RNAPII) at such lesions induces local chromatin acetylation, mediated primarily by the histone acetyltransferase p300. The resulting chromatin relaxation stimulates the dissociation of mature co-transcriptional spliceosomes from nascent RNA and promotes RNA:DNA hybrid (R-loop) formation, leading to ATM activation. In turn, activated ATM modulates chromatin conformation by phosphorylating histone H2A.X and triggering p38MAPK/MSK1-dependent histone H3S10 phosphorylation. Our findings highlight the cross-regulation between chromatin state and ATM signalling as a key component of the cellular response to transcription stress.

Ataxia Telangiectasia Mutated Proteins↗

PubMed2025

DNA topoisomerase II promotes N6-adenosine mRNA methylation.

DNA topoisomerase II (TOP2) is an enzyme that regulates DNA topology, primarily by removing DNA supercoiling. This function is crucial during transcription, as the movement of RNA polymerase II (RNAPII) generates torsional stress. However, the specific role of TOP2 in the regulation of gene expression remains to be fully elucidated, as both TOP2 inhibitors and poisons have been shown to upregulate specific genes. In this study, we show that TOP2 poisoning negatively affects transcription elongation of genes repressed at the level of promoter-proximal pausing. Importantly, this effect is counteracted by defective mRNA N6-adenosine methylation (m6A), which results in altered RNA turnover and pre-mRNA splicing. We propose that TOP2 serves a dual function, supporting the maintenance of basal transcription elongation while simultaneously promoting m6A modification in pre-mRNAs to reduce the overall gene expression output.

RNA Methylation↗