Biology subjects

Zhu, C.

Publications and source records attributed to Zhu, C..

At least 37 records · Page 2Linked to original sources

bioRxiv2026

Solvent accessibility of chlorine-reactive amino acid residues in icosahedral virus structures: A meta-analysis

Free chlorine reacts with viral proteins, but the protein structural determinants of viral resistance to chlorine treatment remain poorly understood. Here, we curated a dataset of 498 icosahedral virus structures, including intact virions and virus-like particles (VLPs), from the Protein Data Bank. Surprisingly, only 6.6% of these structures are associated with published viral chlorine inactivation rate constants (kobs). In these matched cases representing 12 virus families, total and maximum solvent accessible surface areas (SASA) of methionine residues within viral attachment and entry proteins correlated significantly with median kobs (Pearsons r = 0.83 and 0.45, respectively; p < 0.05), suggesting a critical role of methionine exposure in viral resistance phenotypes. Across the full curated dataset, fuzzy c-means clustering upon total and maximum SASA profiles of chlorine-reactive residues demonstrates that the common surrogate panel (MS2, PhiX174, Phi6, PRD1, and PR772) fails to represent the SASA diversity of human viruses. Instead, VLPs and novel phages may serve as better surrogates for chlorine treatment due to SASA profile similarities to human viruses. Our findings highlight that residue SASA features provide a quantitative baseline for screening viral resistance to chlorine and offer a data-driven strategy to select structurally representative virus surrogates for future disinfection studies. SYNOPSISSolvent accessibility of chlorine-reactive residues correlates strongly with viral chlorine resistance, providing a robust quantitative metric to compare chlorine resistance phenotypes across viral capsids. TOC O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/732355v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@dd6bd1org.highwire.dtl.DTLVardef@d17c53org.highwire.dtl.DTLVardef@1394528org.highwire.dtl.DTLVardef@eb6378_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2026

Structural basis for loop-dependent inhibition by AcrIIC1 anti-CRISPR proteins

Most known anti-CRISPR proteins exert inhibition via solitary functional pathways, and few natural Acr homologs have been reported to possess coupled inhibitory mechanisms. Here, we demonstrate that AcrIIC1Boe represses Nme1Cas9 activity through loop-coupled inhibitory effects. Beyond canonical occlusion of the HNH catalytic site, the unique extended loop of AcrIIC1Boe further perturbs sgRNA binding and restricts R-loop maturation to reinforce inhibition. Strikingly, loop deletion completely abrogated this layered inhibitory capacity, confirming that the loop is indispensable for full anti-CRISPR function. Consistently, transplantation of this functional loop into the weakly active AcrIIC1Nme1 markedly upgraded its inhibitory performance. Our findings reveal an unprecedented loop-governed coupled inhibition mode, clarify the structural basis for functional divergence within the AcrIIC1 family, and provide a modular engineering strategy for the rational design and optimization of high-potency anti-CRISPR proteins.

Molecular Biology↗

bioRxiv2026

A dynein-driven nucleokinesis program enables neural crest migration through confined tissues in vivo

Cell migration through confined tissue environments requires precise coordination between the nucleus and the cytoskeleton. Translocation of the nucleus through small pores is a limiting step in confined cell migration. Work in immune and cancer cells has illuminated a key role for actin polymerization and Myosin-II contractility in facilitating nucleus translocation through confinement. However, the microtubule cytoskeleton can also adaptively stabilise under confinement. Microtubule-dependent nucleokinesis constitutes an evolutionarily conserved cellular program ensuring directional nucleus translocation by deployment of cytoplasmic dynein motors. However, whether microtubule-driven nucleokinesis can operate during cell migration through confinement remained so far unexplored. The zebrafish neural crest (NC) provides a unique in vivo system to address this question. NC cells are a highly migratory, multipotent precursors of the vertebrate peripheral nervous system, which traverse diverse environments along the anterior-posterior axis of the embryo. In the head, cranial neural crest (cNC) cells migrate through loosely organised tissues, whereas trunk neural crest (tNC) cells navigate narrowly confined tissue spaces. Here, we show that tNC cells engage a microtubule motor-driven program of nuclear deformation and translocation during confined migration in vivo. Under confinement, tNC cells reorganize their microtubules from a perinuclear meshwork into a polarized, centrosome-associated bundle positioned ahead of the nucleus. Laser ablation reveals that this microtubule array actively pulls and deforms the nucleus. Using pharmacological and genetic approaches, we discover that dynein-dependent pulling forces enable nucleus translocation through confinement. Strikingly, this process occurs independently of Rho/ROCK/myosin II-mediated contractility, revealing a novel neuronal-like mode of nucleokinesis operating in confined tissue environments. Together, our findings uncover a conserved nuclear translocation program deployed during neural crest migration and suggest that microtubule-based nucleokinesis represents a fundamental strategy for navigating tissue confinement in vivo during both central and peripheral nervous system development.

cell biology↗

bioRxiv2026

Accurate de novo design of peptides from programming biophysical landscape

Peptides regulate virtually every cellular process and emerge as transformative modalities in bioengineering and therapeutics. However, the de novo design of functional peptides remains challenging, as peptide-protein interactions are governed by delicate and dynamic biophysics that are difficult to model, and experimental datasets are scarce. Here we present NeoPep, a generative deep-learning framework that encodes biophysical principles to accurately design functional peptides de novo. By integrating over 5 million peptide-protein complexes spanning experimentally determined, sequence mimics, and structure ensembles, NeoPep learns the complex biophysical landscape governing peptide function and enables its programmable control. In prospective application across 10 diverse and challenging targets, NeoPep generated potent peptide binders, agonists, and antagonists with hit rates of 12.5-66.7%, even in the absence of defined binding sites or structure information. Beyond de novo co-design, NeoPep supports standalone structure or sequence redesign, readily discriminating subtle context differences. In the structure redesign mode, it generates highly selective peptides with atomic-level conformational accuracy (C RMSD < 2.0 [A] to our solved cryo-EM structure). This structural precision circumvents the need for experimental structure determination, further accelerating iterative sequence redesign to yield a 43.3-fold improvement in potency. These findings establish a general framework for translating biophysical principles into actionable peptide functions, with broad implications for basic research, bioengineering, and medicine.

molecular biology↗

bioRxiv2026

The molecular asynchrony of single cells

Integrating single-cell transcriptomic and epigenomic data provides a robust framework for investigating gene regulation mechanisms. Existing analyses typically treat these modalities as synchronized features that can be translated in a static manner; however, the temporal delays that underpin cellular kinetics are intrinsic to dynamic biological systems. To address this limitation, we propose utilizing the "molecular asynchrony" within regulatory hierarchies to determine the thermodynamic properties of individual cells. Here, we present SeqTag, a single-cell multiomics sequencing method that simultaneously profiles the transcriptome, chromatin accessibility, and histone modifications, supported by an analytical framework to identify asynchronous states across regulatory layers for characterization of single-cell kinetics. By measuring the epigenetic priming potential and remodeling rates during adult mouse oligodendrogenesis, we delineated a sequential program for bivalency resolution as maturing cells traverse Waddingtons landscape. This process becomes increasingly decoupled with age, a change linked to a drift in progenitor cell-fate probabilities. By identifying entropy-driving regulatory elements, we characterized the aging-related decline in cell identity across various cell types and proposed a dynamic model linking static genetic variants to the risk of late-onset diseases. In summary, our integrated approach established a unified framework for employing multimodal single-cell genomics to model the kinetics of complex cellular processes.

genomics↗

bioRxiv2026

S-nitrosylation of protein kinase A is required for its activation by GPCRs

Stimulation of many G protein-coupled receptors (GPCRs) increases cyclic adenosine monophosphate (cAMP) and nitric oxide (NO). While cAMP-dependent activation of protein kinase A (PKA) is a central regulatory mechanism, a parallel role for NO in GPCR transduction has not been established. Here we show that upon stimulation of multiple GPCRs in heart, brain, and fat, the regulatory subunits of PKA undergo enzymatic S-nitrosylation by SNO-CoA-assisted nitrosylase (SCAN). S-nitrosylation by SCAN is required for dissociation of PKA holoenzymes and activation of PKA. In transgenic and cardiovascular disease models, impaired adrenergic stimulation is identified with deficient S-nitrosylation of PKA, which can be rescued by the drug sodium nitroprusside. Our work suggests a new understanding of GPCR physiology with direct application to the clinical setting.

physiology↗

bioRxiv2026

Combined Checkpoint Inhibition Amplifies Post-Infarction Injury via T Cell-Mediated Macrophage Activation

BackgroundThis study aimed to investigate whether combined PD-1/CTLA-4 immune checkpoint inhibition predisposes the heart to a hyperinflammatory state, thereby exacerbating cardiac injury following acute myocardial infarction (MI), a critical unresolved question in cardio-oncology. MethodsMyocardial infarction was induced in Pd1-/-Ctla4+/- mice, a genetic model mimicking combined checkpoint inhibition. Key mechanistic insights were gained through in vivodepletion of CD8+ T cells (using anti-CD8a antibody) and pharmacological inhibition of the JAK-STAT1 pathway (using Tofacitinib). Cardiac function, structural injury, and immune responses were comprehensively assessed via echocardiography, flow cytometry, immunofluorescence, and molecular analyses. ResultsCompared to wild-type controls, Pd1-/-Ctla4+/- mice exhibited significantly increased post-MI mortality, worse cardiac function, and larger infarct size. Mechanistically, the aggravated injury was driven by an amplified infiltration of activated, IFN-{gamma}-producing CD8+ T cells, which activated the JAK-STAT1 pathway in macrophages, polarizing them towards a pro-inflammatory state. Depleting CD8+ T cells or inhibiting the JAK-STAT1 pathway effectively attenuated macrophage-driven inflammation and improved all aspects of post-MI injury. ConclusionsCombined PD-1/CTLA-4 blockade exacerbates post-infarction cardiac injury by promoting CD8+ T cell-mediated activation of macrophages via the JAK-STAT1 axis. This work elucidates MI as a context-dependent immune-related adverse event in ICI therapy and identifies CD8+ T cells and the JAK-STAT1 pathway as promising therapeutic targets for cardioprotection in these patients. RESEARCH PERSPECTIVEO_ST_ABSWhat Is New?C_ST_ABSO_LIThis study identifies acute myocardial infarction (MI) as a potential, context-dependent immune-related adverse event in the setting of combined PD-1/CTLA-4 checkpoint inhibition, shifting the paradigm beyond the classic focus on myocarditis. C_LIO_LIIt elucidates a novel pathogenic axis where combined checkpoint deficiency exacerbates post-MI injury specifically through CD8+ T cell-derived IFN-{gamma}, which activates macrophages via the JAK-STAT1 pathway. C_LI What Question Should Be Addressed Next?O_LIFuture studies should employ anti-PD-1/CTLA-4 monoclonal antibodies in wild-type or humanized mouse models to validate findings and better recapitulate the pharmacokinetics of clinical ICI therapy, strengthening translational relevance. C_LIO_LIThe long-term consequences of this primed inflammatory state on chronic cardiac remodeling, heart failure development, and the potential interplay with atherosclerosis warrant further investigation. C_LI

immunology↗

bioRxiv2026

Distributed Clonal Deletion Prevents Autoimmune Disease Progression

Self-reactive B cells are generated during normal development and can acquire increased pathogenicity through activation-induced cytidine deaminase (AID)-mediated diversification following activation. Clonal deletion is thought to eliminate these cells, yet how deletion is distributed across developmental and activation stages to prevent autoimmune disease remains unclear. Here, we show that clonal deletion is enforced through temporally distinct mitochondrial apoptosis (MOMP) checkpoints that differentially regulate autoreactive B cell fate and disease progression. Using conditional Bcl-2 expression to inhibit MOMP either before or after B cell activation, we find that early inhibition permits the survival and maturation of autoreactive B cells after peripheral egress, expanding the pool of cells available for activation. These cells subsequently undergo AID-dependent diversification, producing class-switched IgG autoantibodies with expanded antigen breadth that target a wider range of self-antigens and drive lethal, female-biased autoimmune disease characterized by complement activation and kidney pathology. In contrast, inhibition of MOMP only after activation allows the accumulation of germinal center, switched memory, and plasma cells and promotes autoantibody production, but results in more restricted IgG autoreactivity, limited complement activation and limited tissue damage, and normal survival. Notably, early MOMP inhibition does not expand immature bone marrow B cells, indicating that a major clonal deletion checkpoint operates in the periphery rather than during initial B cell generation. Together, these findings support a Distributed Clonal Deletion Model in which early checkpoints restrict the entry of autoreactive B cells into diversification pathways, while later checkpoints limit the persistence of diversified autoreactive clones, thereby constraining autoimmune disease progression. One Sentence SummaryDistributed clonal deletion prevents autoimmune disease progression by restricting the breadth of autoreactive clones entering immune responses, with early MOMP checkpoints limiting diversification and later checkpoints constraining persistence.

immunology↗

bioRxiv2026

Acetyl-CoA Synthetase 1 Regulates Global Histone Propionylation and Metabolic Stress Responses

Cells and organisms are often exposed to various metabolic environments that require adaptive responses for survival. One common way cells adapt to fluctuating nutrient environments is through regulated transcription of metabolic genes. Intermediary metabolites, such as acetyl-CoA, produced by metabolic pathways, serve as cofactors for histone post-translational modifications, which in turn regulate gene expression. However, increasing evidence shows that non-acetyl acyl-CoAs, such as propionyl-CoA, participate in gene regulation during metabolic stress. In this report, we find that histone propionylation functions as a global response to glucose starvation. Furthermore, we find that Acetyl-CoA Synthetase 1 (Acs1) binds chromatin and is the primary enzyme responsible for generating propionyl-CoA in the nucleus. Together, our findings reveal that Acs1-mediated histone propionylation constitutes a novel pathway for metabolic adaptation, linking nutrient availability to chromatin modification.

molecular biology↗

bioRxiv2026

A high-resolution atlas of cattle regulatory variants and their cross-species activity in matched human cells

Identifying causal noncoding variants underlying complex traits in cattle remains challenging because high-resolution functional maps of regulatory variation are lacking. Here we combine massively parallel reporter assays with graph genomics to measure autonomous transcriptional activity from >1.5 billion DNA fragments spanning both cattle subspecies. In primary bovine cells, we assay >15 million variants and identify >150,000 expression-modulating variants enriched at cattle eQTL and GWAS loci. This enables the refinement of broad association signals to small sets of candidate functional regulatory variants. Our haplotype-aware framework captures rare, multi-allelic and tightly linked variants poorly resolved by conventional eQTL studies, and quantifies the disproportionate impact of larger variants on transcription. Furthermore, we use these data to train a deep-learning model that successfully predicts bovine promoter activity directly from sequence. Profiling the same cattle DNA in matched primary human cells reveals widespread conservation of promoter and enhancer activity, allelic effects and regulatory grammar, supporting the transfer of annotations and models across species. However, species-dependent effects are enriched in evolutionarily young sequences and p53-family motifs, highlighting the limits to simple cross-species extrapolation. Together, these data provide a high-resolution atlas of cattle regulatory variation and a framework for prioritising causal noncoding variants for cattle trait improvement.

genetics↗

bioRxiv2026

Hepatocellular Carcinoma Revisited from Single Cell Sequencing: Dynamic Evolution from Epithelial Dedifferentiation to Mesenchymal Remodeling

BackgroundSingle-cell RNA sequencing has provided new insights into hepatocellular carcinoma (HCC); however, a unified understanding of epithelial heterogeneity and immune evasion strategies in HCC remains lacking. MethodsWe re-analyzed publicly available single-cell datasets using conventional bioinformatics pipelines. Cell-type annotation of epithelial and T cell populations was further validated across multiple independent datasets to ensure robustness. ResultsWe systematically examined epithelial, immune, myeloid, and stromal lineages. In addition to recapitulating previously reported findings, we identified several novel observations. Notably, we uncovered a three-step dedifferentiation trajectory in epithelial cells and confirmed a bidirectional differentiation pattern within CD8{square} T cells. We also identified a subset of GZMK{square} CD4{square} T cells, whose transcriptional features resemble but are distinct from T follicular helper (Tfh) cells. Importantly, transcriptional drift within myeloid populations appeared to be closely associated with immune responsiveness. Furthermore, ligand-receptor analysis highlighted a potential cooperative role of LAMP3{square} dendritic cells and Tfh cells in promoting lymphoid follicle formation. ConclusionsIn the era of rapidly evolving single-cell sequencing technologies, we provide a framework for understanding cellular heterogeneity in HCC, which awaits further validation in future studies.

cancer biology↗

bioRxiv2026

Low-Intensity Focused Ultrasound Enhances Meningeal Lymphatic Drainage for Preventing Cognitive Decline in Alzheimer's Disease

Meningeal lymphatic vessels (mLVs) are vital for brain waste clearance, making them a promising therapeutic target. However, effective modulation strategies for mLVs with translational potential remain underdeveloped. Here, we develop a low-intensity focused ultrasound (LIFU) strategy that precisely targets the vault cranial meninges to non-invasively facilitate mLVs drainage. Using models of Alzheimers disease (AD) and aging, we demonstrate that this approach promotes CSF drainage, prevents cognitive decline, and reduces pathological biomarkers. Mechanistically, RNA sequencing combined with calcium imaging in vitro reveals that LIFU activates the Piezo1 ion channel in lymphatic endothelial cells, whereas pharmacological inhibition of Piezo1 abolishes LIFUs therapeutic effects. Compliant with FDA safety guidelines, this LIFU protocol demonstrates strong clinical translatability. If its efficacy is clinically confirmed, LIFU offers a promising therapy for neurodegenerative diseases triggered by waste accumulation.

neuroscience↗

bioRxiv2026

Identification and Characterization of Neoplastic Cells in Keratin-Positive Giant Cell-Rich Tumors

Keratin-positive giant cell-rich tumor (KPGCT) is a newly described bone and soft tissue tumor. The tumor is characterized by scattered keratin-positive cells and the presence of HMGA2::NCOR2 fusions. It is not known if the HMGA2::NCOR2 fusion is located in the keratin-positive cells, and little is known about how KPGCT develops. KPGCT shares some histologic features with tenosynovial giant cell tumor (TGCT), a soft tissue tumor with CSF1 rearrangements. Single-nuclei RNA sequencing (snRNA-seq) and Xenium spatial transcriptomics were used to elucidate the mechanisms driving KPGCT and compare KPGCT to TGCT. We show that the neoplastic cells in KPGCT constitute only a minority of cells in the tumor, and that they co-express keratin, HMGA2 and CSF1. The neoplastic cells in KPGCT express no synovial markers, confirming KPGCT as a distinct entity, separate from TGCT. The bulk of the tumor consists of CSF1R-expressing macrophages and osteoclast-like giant cells, suggesting an important role for CSF1-CSF1R signaling. In addition, we find that the cells with the HMGA2 translocation show activation of the hippo signaling pathway, which is known to regulate CSF1 expression. We show that the CSF1-CSF1R axis, possibly regulated through the hippo signaling pathway, plays an important role in KPGCT. This axis likely stimulates the migration and proliferation of macrophages, which form the majority of cells in the tumor, as well as their differentiation into osteoclasts-like giant cells. These results provide a rationale for the use of CSF1R inhibitors, which have already shown efficacy in TGCT, as a therapy for KPGCT. SignificanceKeratin-positive giant cell-rich tumor (KPGCT) is a rare, newly described soft tissue and bone tumor. By examining this tumour on a single-cell level, we confirm the identity of the neoplastic cells on a molecular level, showing these form a minority of cells in the tumor. We show that activation of the hippo pathway in the neoplastic cells is a likely driver of tumorigenesis. Additionally, we show the neoplastic cells produce large amounts of CSF1, attracting the macrophages that form the majority of cells in the tumor. This finding gives supporting evidence for anecdotal reports of response to CSF1 inhibitor therapy. Finally, we identify key differences between KPGCT and tenosynovial giant cell tumor, a tumor that shares histological features with KPGCT.

cancer biology↗

bioRxiv2026

Notch mediated lateral inhibition is shaped by morphological differences to reinforce bias toward signal-sending or receiving roles

During neurogenesis, neuroblasts are selected from proneural-competent cells through lateral inhibition, a process controlled by the evolutionarily conserved Notch signalling pathway. By tracking transcription from Notch-target genes and cell morphologies in real time, we discovered that the presumptive neuroblast never initiates target-gene transcription. This implies a pre-existing bias directs Notch signalling. The bias correlates with a heterogeneity in apical cell areas which is further reinforced during neuroblast selection. Additionally, the length and duration of neuroblast-neighbour cell contacts predict the likelihood of transcription. Using mathematical modelling we show that lateral inhibition seeded with subtle morphological differences can bias cells toward signal-sending or receiving roles before transcriptional feedback occurs. Notch activation further alters apical cell area, reinforcing the initial bias. We propose that signalling and cell mechanics work together to ensure the robust selection of a single neural precursor.

developmental biology↗

bioRxiv2026

A Targeting Parameter Space for Personalized 4x1 HD-tES: Montage Description, Optimization and Application

BackgroundPersonalized optimization of 4x1 high-definition transcranial electrical stimulation (HD-tES) faces inherent trade-offs between montage flexibility, computational efficiency, and implementation accessibility. Conventional 10-10 electrode systems constrain placement to discrete landmark positions, while unconstrained optimization relies on stochastic algorithms that risk converging to local optima and requires neuronavigation equipment often unavailable in rehabilitation settings. Here we introduce a scalp geometry-based parameter space (SGP) that parameterizes 4x1 HD-tES montages using three intuitive scalp-defined parameters--position, radius, and orientation--and characterize parameter-performance regularities through exhaustive electric field simulations across 30 subjects and 624 cortical targets (>3.6 million configurations). ResultsPosition primarily determined proximity to optimal performance, radius governed the intensity-focality trade-off, and orientation served as fine-tuning. Exploiting these regularities, a minimal search space (SGP-MSS) was constructed that reduced computational complexity by over 90% while guaranteeing global optima identification. Compared with standard 10-10 montages, SGP-MSS achieved up to 99% higher targeting intensity and 126% higher focality (all p < 0.0001). Compared with lead-field-free optimization, SGP-MSS achieved comparable performance with greater cross-subject stability. ConclusionsThe SGP framework enables efficient individualized HD-tES optimization without neuronavigation. Its scalp-based parameterization supports electrode positioning via standard cranial landmark measurements, facilitating translation to routine clinical and home-based rehabilitation settings.

biophysics↗

bioRxiv2026

Identification of a somatic H3K23me3 methyltransferase SET-19 in C. elegans

Histone methylation plays essential roles in modulating chromatin organization and gene expression. H3K23 methylation is a conserved histone modification, yet its biological roles and the enzymes responsible for its deposition remain poorly understood. Here, we show that the loss of set-19 leads to a pronounced reduction in H3K23 methylation in C. elegans, as revealed by quantitative mass spectrometry, western blotting, and immunofluorescence staining. In vitro biochemical assays show that recombinant SET-19 proteins purified from E. coli directly catalyze H3K23 methylation. Genome-wide chromatin immunoprecipitation assays reveal that H3K23me3 is enriched at heterochromatic regions and that loss of set-19 alters H3K23me3 levels, accompanied by derepression of gene expression. Genetic analyses indicate that SET-19 is dispensable for both germline and somatic RNAi as well as transgenerational epigenetic inheritance of RNAi. SET-19 is predominantly expressed in somatic cells and specifically mediates H3K23me3 deposition in somatic tissues. The loss of set-19 causes a developmental delay without affecting fertility. Together, our results identify SET-19 as a somatic H3K23 methyltransferase and link H3K23me3 to gene repression in C. elegans.

genetics↗

bioRxiv2026

A Deep Learning Framework for Predicting Gut Microbe-Host Receptor Interactions

MotivationGut microbiota regulates host health through complex protein-protein interactions. However, deciphering this specific interactions between microbiota and human receptors remains a significant challenge due to the lack of specialized computational tools. ResultsLeveraging the hypothesis of cell communication and relevant data, HMI-Pred initially builds an ensemble classifier to screen for potential ligand sequences within microbial genomes. It then jointly evaluates sequence semantics and molecular docking to predict potential microbe-host receptor interactions.HMI-Pred achieved robust performance with F1-scores of 0.901 for microbial ligand identification and 0.883 for interaction prediction. Application to 332,381 microbial proteins revealed distinct interaction patterns: histone deacetylases (HDACs) served as broad-spectrum targets (mean score > 0.80), while G protein-coupled receptors (GPCRs) exhibited high specificity (scores 0.42-0.61). Furthermore, literature mining validated over 47% of the functional predictions, and specific immunomodulatory interactions were confirmed in Akkermansia muciniphila.HMI-Pred provides a valuable computational tool for decoding host-microbe signaling networks and facilitating the discovery of microbiome-based therapeutic targets. AvailabilityThe source code and documentation are available at https://github.com/YangLab-BUPT/HMI-Pred. Contactlihm@bupt.edu.cn

microbiology↗

bioRxiv2026

PARP1 directly disassembles nucleosomes to regulate DNA repair

Upon DNA damage, chromatin remodeling is rapidly initiated to promote chromatin accessibility, thereby facilitating the recruitment and assembly of repair factors. Although this enhanced accessibility has been linked to poly(ADP-ribose) polymerase (PARP) activity, the mechanism by which cells overcome the nucleosome barrier remains unclear. Using our designer chromatin system, we uncovered a previously uncharacterized activity of PARP1, whereby it directly and asymmetrically evicts histone dimers proximal to DNA strand breaks from nucleosomes to generate oriented hexasomes. In the presence of HPF1, PARP1 generates stable PARylated hexasomes, an open chromatin intermediate that can serve as a bifunctional hub for recruitment of DNA- and PAR-dependent factors. Using cellular assays, we demonstrated that PARP activity is both required and sufficient to drive chromatin accessibility and the recruitment of repair factors, with direct involvement of subnucleosomal species. Unexpectedly, we identified the C-terminal tail of histone H2A, a motif harboring recurrent cancer-associated mutations, as a critical determinant of efficient PARP1-mediated nucleosome disassembly. Deletion of the H2A tail sensitizes cells to DNA-damaging agents and PARP inhibitors, implicating a functional role of PARP1-mediated nucleosome disassembly in DNA repair. Together, our findings support a model in which PARP1 directly drives histone eviction, leading to the formation of subnucleosomes that facilitate efficient DNA repair.

molecular biology↗