Biology subjects

Adelman, K.

Publications and source records attributed to Adelman, K..

At least 19 recordsLinked to original sources

bioRxiv2026

Nascent transcription profiling identifies H3K36 methylation as a custodian of the somatic transcriptome

Faithful gene expression not only requires activation of productive transcription units, but also suppression of aberrant initiation within or between gene bodies. In Saccharomyces, Set2-mediated H3 lysine-36 methylation (H3K36me) recruits a deacetylase complex that removes acetylation deposited behind elongating RNA polymerase II, preventing cryptic initiation. Whether metazoans require Set2 or the K36 residue itself for this function has been difficult to test. Here, we combined PRO-seq, RNA-seq, and chromatin profiling in Drosophila wing imaginal discs to define individual contributions of Set2, H3.2K36 and H3.3K36 to transcriptome fidelity. Intragenic initiation events are abundant but largely unresponsive to loss of K36 methylation. Aberrant initiation instead concentrates in repetitive, extragenic chromatin, co-marked by H3K9me2/3 and H3K36me2 but depleted of H3K36me3, a dual heterochromatin signature that is also conserved in mammals. Within this compartment, piRNA clusters, germline-restricted genes, and LTR and LINE retrotransposons are aberrantly activated in somatic tissue. A K36R substitution in H3.2, but not in H3.3, derepresses these loci to a far greater extent than deleting Set2, which retains K36me2 but cannot deposit K36me3. Thus, metazoan H3K36 safeguards the somatic transcriptome principally within heterochromatin, rather than within gene bodies.

genetics↗

bioRxiv2026

Pluripotency and Transcriptional Pausing Disrupt Circadian Rhythms to Facilitate the Enrichment of Cancer Stem Cells

Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype, enriched for cancer stem cells (CSCs), which are the cause of tumor recurrence. CSCs are responsible for tumor initiation and propagation; however, the molecular mechanisms underlying their formation remain largely unclear. We show that carboplatin treated TNBC cells lose their circadian rhythms and promote the enrichment of CSCs. Notably, genetic ablation of the circadian clock by itself, without carboplatin treatment, facilitated the formation of CSCs along with their ability to generate 3D tumorspheres and mouse tumors enriched with CSCs. Mechanistically, we identified an antagonistic interplay between the circadian clock and pluripotency, whereby the core pluripotent factor OCT4 disrupts the expression of circadian timekeeping genes to disable the circadian clock. Furthermore, we uncovered a transcriptional pausing program, controlling the circadian clock, to be perturbed in carboplatin treated TNBC cells. Concordantly, based on gene expression analysis from The Cancer Genome Atlas (TCGA), we found that the uncoupling of transcriptional pausing and the circadian clock correlated with low survivability across diverse cancer types. Moreover, cancer patients with poor prognosis exhibit low expression of the core timekeeping genes Clock, Npas2, Bmal1 and Rorc. Lastly, we restored circadian rhythms in Oct4 deficient TNBC cells and impaired their ability to generate tumorspheres and decreased the number of CSCs in mouse tumors. Overall, our findings demonstrate an unprecedented mechanism for the formation of CSCs that is dependent on the loss of circadian rhythms and thereby has eminent implications for developing new cancer therapies.

cancer biology↗

bioRxiv2026

Elongin B orchestrates chromatin and transcriptional programs in H3K27M-mutant diffuse midline glioma

Recurrent driver mutations in genes encoding histone H3 (H3.3K27M and H3.1K27M) are observed in [~]80% of diffuse midline gliomas (DMG), which lead to aberrant gene regulation, yet the specific RNA polymerase II (Pol2) regulators that induce transcriptional dysregulation in DMG are not fully defined. We identified multiple regulators of Pol2 elongation as DMG genetic dependencies in a chromatin-focused CRISPR screen. Additional studies confirm that knockout (KO) of the Pol2 SIII complex gene elongin B (ELOB) inhibits DMG cell proliferation in tissue culture and tumor growth in xenograft models. Further genomic analyses reveal that ELOB binding sites are enriched in H3K27M oncohistones and that ELOB KO alters H3K27me3 and H3K27M incorporation at thousands of genomic regions, implicating ELOB in the maintenance of dysfunctional chromatin states in DMG. Correspondingly, PRO-seq and RNA-seq profiling reveal that ELOB loss disrupts Pol2 transcriptional activity and alters the expression of transcripts involved in metabolism, proliferation, and brain development. These findings suggest that Pol2 elongation factors like ELOB cooperate with H3K27M oncohistones to maintain the epigenetic and transcriptional landscape driving DMG malignancy.

cancer biology↗

bioRxiv2025

Dual Modes of Gene Regulation by CDK12

The process of transcription is driven forward by the activity of kinases including CDK7, CDK9 and CDK12. Accordingly, acute inhibition of any of these kinases results in profound downregulation of gene expression. Here, we discover that loss or inhibition of CDK12 also significantly upregulates a set of coding and non-coding loci, whose activation could contribute to the anti-proliferative effects of CDK12 inhibitors. Mechanistically, CDK12 inhibition impairs transcription elongation, leading to increased RNA polymerase II termination or arrest in long genes. However, short genes such as MYC and enhancer RNAs are highly transcribed in the absence of CDK12 activity. Indeed, in HER2+ breast cancer, a malignancy where CDK12 is co-amplified with HER2 and its expression correlates with disease status, CDK12 inhibition markedly elevates MYC expression to induce lethality. The dual effects of CDK12 inhibition elucidated herein clarify its role in transcriptional control and have significant translational implications.

cancer biology↗

bioRxiv2025

Structure and function of IWS1 in transcription elongation

Transcription elongation by RNA polymerase II is a tightly regulated process that requires coordinated interactions between transcription elongation factors. IWS1 (Interacts with SPT6) has been implicated as a core elongation factor, but its molecular role remains unclear. We show that the intrinsically disordered C-terminal region of IWS1 contains short linear motifs (SLiMs) that multivalently engage the elongation machinery. Using cryo-electron microscopy, we map SLiMs in IWS1 that interact with Pol II subunits RPB1, RPB2, and RPB5, as well as elongation factors DSIF, SPT6, and ELOF1. Functional assays demonstrate that distinct IWS1 SLiMs specify IWS1 recruitment and IWS1-dependent transcription stimulation. IWS1 recruitment to the transcription elongation complex depends on association via the RPB1 jaw and binding of downstream DNA. Transcription elongation stimulation requires interactions with the RPB2 lobe and ELOF1. We identify other transcription elongation factors including ELOA and RECQL5 that bind the RPB1 jaw and demonstrate that IWS1 protects the activated transcription elongation complex from RECQL5 inhibition. We also reveal the binding of the histone reader and IWS1 interactor LEDGF to a transcribed downstream nucleosome. Our findings establish IWS1 as a modular scaffold that helps organize the transcription elongation complex, illustrating how disordered regions regulate transcription elongation.

molecular biology↗

bioRxiv2025

GPCR Antagonism via Antibody-Mediated Rewiring of Receptor Trafficking and Degradation

G-protein coupled receptors (GPCRs) represent one of the most important yet incompletely targeted classes of therapeutic proteins. Here, we report a novel strategy for functional GPCR antagonism through antibody-mediated endocytosis and lysosomal degradation. Our engineered bispecific antibodies, termed GPCR-TfR1 Targeting Chimeras (GTACs), achieve potent and selective downregulation of various GPCRs, including RXFP1 and CCR6, critical cancer and immune drug targets that are difficult to antagonize with conventional approaches. GTACs led to complete inhibition of receptor activity with over 100-fold greater potency than conventional antibody antagonists. Using four-color imaging, we elucidated the trafficking mechanism of both the target protein and TfR1 in living cells. The GTAC platform enables robust antagonism of signaling across diverse GPCR families and establishes induced endocytosis and lysosomal trafficking as a fundamentally new paradigm for therapeutic GPCR modulation.

bioengineering↗

bioRxiv2025

Restrictor slows early transcription elongation to render RNA polymerase II susceptible to termination at non-coding RNA loci

The eukaryotic genome is broadly transcribed by RNA polymerase II (RNAPII) to produce protein-coding messenger RNAs (mRNAs) and a repertoire of non-coding RNAs (ncRNAs). Whereas RNAPII is very processive during mRNA transcription, it terminates rapidly during synthesis of many ncRNAs, particularly those that arise opportunistically from accessible chromatin at gene promoters or enhancers. The divergent fates of mRNA versus ncRNA species raise many questions about how RNAPII and associated machineries discriminate functional from spurious transcription. The Restrictor complex, comprised of the RNA binding protein ZC3H4 and RNAPII-interacting protein WDR82, has been implicated in restraining the expression of ncRNAs. However, the determinants of Restrictor targeting and the mechanism of transcription suppression remain unclear. Here, we investigate Restrictor using unbiased sequence screens, and rapid protein degradation followed by nascent RNA sequencing. We find that Restrictor promiscuously suppresses early elongation by RNAPII, but this activity is blocked at most mRNAs by the presence of a 5 splice site. Consequently, Restrictor is a critical determinant of transcription directionality at divergent promoters and prevents transcriptional interference. Finally, our data indicate that rather than directly terminating RNAPII, Restrictor acts by reducing the rate of transcription elongation, rendering RNAPII susceptible to early termination by other machineries.

genomics↗

bioRxiv2024

CEBPA repression by MECOM blocks differentiation to drive aggressive leukemias

Acute myeloid leukemias (AMLs) have an overall poor prognosis with many high-risk cases co-opting stem cell gene regulatory programs, yet the mechanisms through which this occurs remain poorly understood. Increased expression of the stem cell transcription factor, MECOM, underlies one key driver mechanism in largely incurable AMLs. How MECOM results in such aggressive AML phenotypes remains unknown. To address existing experimental limitations, we engineered and applied targeted protein degradation with functional genomic readouts to demonstrate that MECOM promotes malignant stem cell-like states by directly repressing pro-differentiation gene regulatory programs. Remarkably and unexpectedly, a single node in this network, a MECOM-bound cis-regulatory element located 42 kb downstream of the myeloid differentiation regulator CEBPA, is both necessary and sufficient for maintaining MECOM-driven leukemias. Importantly, targeted activation of this regulatory element promotes differentiation of these aggressive AMLs and reduces leukemia burden in vivo, suggesting a broadly applicable differentiation-based approach for improving therapy.

cancer biology↗

bioRxiv2024

Notch induces transcription by stimulating release of paused RNA Pol II without increasing chromatin accessibility

Notch proteins undergo ligand-induced proteolysis to release a nuclear effector that influences a wide range of cellular processes by regulating transcription. Despite years of study, however, how Notch induces the transcription of its target genes remains unclear. Here, we comprehensively examined the response to human Notch1 across a time course of activation using high-resolution genomic assays of chromatin accessibility and nascent RNA production. Our data reveal that Notch induces target gene transcription primarily by releasing paused RNA polymerase II (RNAPII). Moreover, in contrast to prevailing models suggesting that Notch acts by promoting chromatin accessibility, we found that open chromatin was established at Notch-responsive regulatory elements prior to Notch signal induction, through SWI/SNF-mediated remodeling. Together, these studies show that the nuclear response to Notch signaling is dictated by the pre-existing chromatin state and RNAPII distribution at the time of signal activation.

genomics↗

bioRxiv2023

Decoding the Epigenetics and Chromatin Loop Dynamics of Androgen Receptor-Mediated Transcription

Androgen receptor (AR)-mediated transcription plays a critical role in normal prostate development and prostate cancer growth. AR drives gene expression by binding to thousands of cis-regulatory elements (CRE) that loop to hundreds of target promoters. With multiple CREs interacting with a single promoter, it remains unclear how individual AR bound CREs contribute to gene expression. To characterize the involvement of these CREs, we investigated the AR-driven epigenetic and chromosomal chromatin looping changes. We collected a kinetic multiomic dataset comprised of steady-state mRNA, chromatin accessibility, transcription factor binding, histone modifications, chromatin looping, and nascent RNA. Using an integrated regulatory network, we found that AR binding induces sequential changes in the epigenetic features at CREs, independent of gene expression. Further, we showed that binding of AR does not result in a substantial rewiring of chromatin loops, but instead increases the contact frequency of pre-existing loops to target promoters. Our results show that gene expression strongly correlates to the changes in contact frequency. We then proposed and experimentally validated an unbalanced multi-enhancer model where the impact on gene expression of AR-bound enhancers is heterogeneous, and is proportional to their contact frequency with target gene promoters. Overall, these findings provide new insight into AR-mediated gene expression upon acute androgen simulation and develop a mechanistic framework to investigate nuclear receptor mediated perturbations.

genomics↗

bioRxiv2023

Transcriptional shut-off of MAP kinase signaling enables pluripotency maintenance during diapause

Exposure of unicellular or multicellular organisms to adverse environmental conditions, including nutrient deprivation, may induce a state of suspended animation or diapause. The diapause minimizes the organisms reliance on external energy sources and ensures survival. Among different forms of diapause, embryonic diapause, caused by a limited supply of nutrients to the growing embryos, is particularly challenging for the organism. Diapause embryos stop developing at the peak of pluripotent cell differentiation and maintain this undifferentiated yet entirely vital state despite the overall reduction in anabolic processes and genome-wide transcriptional repression. Using ES cells commonly employed to study the mechanism of embryonic diapause, we solve the paradox of the cell maintenance in an undifferentiated ES cell state during diapause. We find that broad transcriptional repression by long-term inhibition of the bromodomain and extra-terminal (BET) proteins causes diapause. These diapause ES cells upregulate a functionally linked group of genes encoding negative regulators of MAP kinase signaling (NRMKS), which play a crucial role in ES cell differentiation. We find that elevated NRMKS expression is a hallmark of the diapause cells and cells exposed to diapause-inducing conditions, including mTOR inhibition, and is required for the maintenance of ES cell pluripotency during diapause. Mechanistically, exposure of ES cells to diapause-inducing conditions leads to rapid decline of the Capicua transcriptional repressor (CIC) at the NRMKS gene promoters, followed by transcriptional upregulation of NRMKS genes. The mTOR and BET-dependent transcriptional switch supporting the undifferentiated state of the diapause ES cells suggests a broader usage of this mechanism in maintaining the undifferentiated state of metabolically dormant stem- or stem-like cells in different tissues.

cell biology↗

bioRxiv2023

RNA polymerase II pausing is essential during spermatogenesis for appropriate gene expression and completion of meiosis

Male germ cell development requires precise regulation of gene activity in a cell-type and stage-specific manner, with perturbations in gene expression during spermatogenesis associated with infertility. Here, we use steady-state, nascent and single-cell RNA sequencing strategies to comprehensively characterize gene expression across male germ cell populations, to dissect the mechanisms of gene control and provide new insights towards therapy. We discover a requirement for pausing of RNA Polymerase II (Pol II) at the earliest stages of sperm differentiation to establish the landscape of gene activity across development. Accordingly, genetic knockout of the Pol II pause-inducing factor NELF in immature germ cells blocks differentiation to mature spermatids. Further, we uncover unanticipated roles for Pol II pausing in the regulation of meiosis during spermatogenesis, with the presence of paused Pol II associated with double strand break formation by SPO11, and disruption of SPO11 expression in germ cells lacking NELF.

genomics↗

bioRxiv2023

Global Identification of Direct SWI/SNF Targets Reveals Compensation by EP400

Mammalian SWI/SNF chromatin remodeling complexes move and evict nucleosomes at gene promoters and enhancers to modulate DNA access. Although SWI/SNF subunits are commonly mutated in disease, therapeutic options are limited by our inability to predict SWI/SNF gene targets and conflicting studies on functional significance. Here, we leverage a fast-acting inhibitor of SWI/SNF remodeling to elucidate direct targets and effects of SWI/SNF. Blocking SWI/SNF activity causes a rapid and global loss of chromatin accessibility and transcription. Whereas repression persists at most enhancers, we uncover a compensatory role for the EP400/TIP60 remodeler, which reestablishes accessibility at most promoters during prolonged loss of SWI/SNF. Indeed, we observe synthetic lethality between EP400 and SWI/SNF in lung cancer cell lines and human cancer patient data. Our data define a set of molecular genomic features that accurately predict gene sensitivity to SWI/SNF inhibition in diverse cancer cell lines, thereby improving the therapeutic potential of SWI/SNF inhibitors. Highlights- Genes repressed by long-term SWI/SNF loss do not accurately reflect direct targets - Promoters that fail to reestablish activity are those lacking a compensatory remodeler - Accessibility and activity recovery requires EP400, synthetically lethal with SWI/SNF - SWI/SNF dependence in cancer cells can be predicted from the promoter chromatin state

molecular biology↗

bioRxiv2022

Splicing modulators impair DNA damage response and induce killing of cohesin-mutant MDS/AML

Splicing modulation is a promising treatment strategy pursued to date only in splicing-factor mutant cancers; however, its therapeutic potential is poorly understood outside of this context. Like splicing factors, genes encoding components of the cohesin complex are frequently mutated in cancer, including myelodysplastic syndromes (MDS) and secondary acute myeloid leukemia (AML), where they are associated with poor outcomes. Here, we show that cohesin mutations are biomarkers of sensitivity to drugs targeting the splicing-factor SF3B1 (H3B-8800 and E-7107). We identify drug-induced alterations in splicing and corresponding reduced gene expression of a large number of DNA repair genes, including BRCA1 and BRCA2, as the mechanism underlying this sensitivity in cell line models, primary patient samples and patient-derived xenograft (PDX) models of AML. We find that DNA damage repair genes are particularly sensitive to exon skipping induced by SF3B1 modulators given their long length and large number of exons per transcript. Furthermore, we demonstrate that treatment of cohesin-mutant cells with SF3B1 modulators not only results in impaired DNA damage response and accumulation of DNA damage, but it significantly sensitizes cells to subsequent killing by PARP inhibitors and chemotherapy, and leads to improved overall survival of PDX models of cohesin-mutant AML in vivo. Our findings expand the potential therapeutic benefits of SF3B1 splicing modulators to include cohesin-mutant MDS and AML, and we propose this as a broader strategy for therapeutic targeting of other DNA damage-repair deficient cancers. One Sentence SummaryWe identify an unexpected effect of SF3B1 splicing inhibitors on regulation of DNA damage repair genes and show efficacy of combination treatment in cohesin-mutant MDS and AML.

cancer biology↗

bioRxiv2022

NIPBL and WAPL balance cohesin activity to regulate chromatin folding and gene expression

The relationship between cohesin-mediated chromatin looping and gene expression remains unclear. We investigated the roles of NIPBL and WAPL, two regulators of cohesin activity, in chromatin folding and transcription in human cells. Consistent with their opposing roles in cohesin regulation, depletion of these factors showed opposite effects on levels of chromatin-bound cohesin and spatial insulation of neighboring domains. We find that NIPBL or WAPL depletion each alter the expression of ~2,000 genes, most of which are uniquely sensitive to either regulator. We find that each set of differentially expressed genes are enriched at chromatin loop anchors and clustered within the genome, suggesting there are genomic regions sensitive to either more or less cohesin. Remarkably, co-depletion of both regulators rescued chromatin misfolding and gene misexpression compared to either single knockdown. Taken together, we present a model in which the relative, rather than absolute, levels of NIPBL and WAPL are required to balance cohesin activity in chromatin folding to regulate transcription.

genetics↗

bioRxiv2021

Mapping information-rich genotype-phenotype landscapes with genome-scale Perturb-seq

A central goal of genetics is to define the relationships between genotypes and phenotypes. High-content phenotypic screens such as Perturb-seq (pooled CRISPR-based screens with single-cell RNA-sequencing readouts) enable massively parallel functional genomic mapping but, to date, have been used at limited scales. Here, we perform genome-scale Perturb-seq targeting all expressed genes with CRISPR interference (CRISPRi) across >2.5 million human cells and present a framework to power biological discovery with the resulting genotype-phenotype map. We use transcriptional phenotypes to predict the function of poorly-characterized genes, uncovering new regulators of ribosome biogenesis (including CCDC86, ZNF236, and SPATA5L1), transcription (C7orf26), and mitochondrial respiration (TMEM242). In addition to assigning gene function, single-cell transcriptional phenotypes allow for in-depth dissection of complex cellular phenomena - from RNA processing to differentiation. We leverage this ability to systematically identify the genetic drivers and consequences of aneuploidy and to discover an unanticipated layer of stress-specific regulation of the mitochondrial genome. Our information-rich genotype-phenotype map reveals a multidimensional portrait of gene function and cellular behavior.

genomics↗

bioRxiv2021

Screening thousands of transcribed coding and non-coding regions reveals sequence determinants of RNA polymerase II elongation potential

Organismal growth and development rely on RNA Polymerase II (RNAPII) synthesizing the appropriate repertoire of messenger RNAs (mRNAs) from protein-coding genes. Productive elongation of full-length transcripts is essential for mRNA function, however what determines whether an engaged RNAPII molecule will terminate prematurely or transcribe processively remains poorly understood. Notably, despite a common process for transcription initiation across RNAPII-synthesized RNAs1, RNAPII is highly susceptible to termination when transcribing non-coding RNAs such as upstream antisense RNAs (uaRNAs) and enhancers RNAs (eRNAs)2, suggesting that differences arise during RNAPII elongation. To investigate the impact of transcribed sequence on elongation potential, we developed a method to screen the effects of thousands of INtegrated Sequences on Expression of RNA and Translation using high-throughput sequencing (INSERT-seq). We found that higher AT content in uaRNAs and eRNAs, rather than specific sequence motifs, underlies the propensity for RNAPII termination on these transcripts. Further, we demonstrate that 5 splice sites exert both splicing-dependent and autonomous, splicing-independent stimulation of transcription, even in the absence of polyadenylation signals. Together, our results reveal a potent role for transcribed sequence in dictating gene output at mRNA and non-coding RNA loci, and demonstrate the power of INSERT-seq towards illuminating these contributions.

genomics↗

bioRxiv2020

Rapid and Efficient Co-Transcriptional Splicing Enhances Mammalian Gene Expression

Pre-mRNA processing steps are tightly coordinated with transcription in many organisms. To determine how co-transcriptional splicing is integrated with transcription elongation and 3 end formation in mammalian cells, we performed long-read sequencing of individual nascent RNAs and PRO-seq during mouse erythropoiesis. Splicing was not accompanied by transcriptional pausing and was detected when RNA polymerase II (Pol II) was within 75 - 300 nucleotides of 3 splice sites (3SSs), often during transcription of the downstream exon. Interestingly, several hundred introns displayed abundant splicing intermediates, suggesting that splicing delays can take place between the two catalytic steps. Overall, splicing efficiencies were correlated among introns within the same transcript, and intron retention was associated with inefficient 3 end cleavage. Remarkably, a thalassemia patient-derived mutation introducing a cryptic 3SS improves both splicing and 3 end cleavage of individual {beta}-globin transcripts, demonstrating functional coupling between the two co-transcriptional processes as a determinant of productive gene output.

molecular biology↗