Biology subjects

Han, Y.

Publications and source records attributed to Han, Y..

At least 73 records · Page 4Linked to original sources

bioRxiv2026

Tumor-infiltrating natural killer cell profiling for therapeutic stratification in patients with resectable non-small cell lung cancer

ObjectiveNeoadjuvant chemoimmunotherapy has improved outcomes in resectable non-small cell lung cancer (NSCLC), yet its real-world implementation is often challenged by surgical delays, immune-mediated fibrosis, and postoperative complications. Smokers with NSCLC, despite a high risk for surgical morbidity, show enhanced responses to neoadjuvant chemoimmunotherapy. This study aimed to identify smoking-associated immune cell determinants that could guide treatment strategies. MethodsSingle-cell RNA sequencing (scRNAseq) was performed on 61 lung tissues from non-smokers and smokers to identify smoking-related immune compositions. The scRNAseq data from 19 invasive lung adenocarcinomas were used to validate their presence in the tumor-immune microenvironment. Bulk RNA sequencing data from 102 resected NSCLC and 24 NSCLC patients treated with neoadjuvant chemoimmunotherapy followed by surgery were used for in silico cellular deconvolution and outcome analyses. ResultsAmong 135 lung cellular phenotypes, two natural killer (NK) cell subsets were strongly associated with smoking and chronic obstructive pulmonary disease (COPD) severity. "Stress-responsive" NK (NKSR) cells exhibited immature features and cytokine-responsive features, and "Adaptive and immunoregulatory NK" (NKAIR) cells showed mature features and elevated multiple immune checkpoint expression. High intratumoral NKSR cells correlated with improved survival after surgery, particularly in current smokers. Conversely, tumors with low NKSR and high NKAIR cells responded more favorably to neoadjuvant chemoimmunotherapy. ConclusionsIntratumoral NK cell phenotyping may aid in therapeutic stratification in patients with NSCLC. NKSR cell preservation predicts benefit from upfront surgery, while NKAIR cell enrichment indicates improved response to neoadjuvant chemoimmunotherapy. These NK cell profiles may help optimize treatment by balancing therapeutic benefit and risk. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/696292v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@168bc03org.highwire.dtl.DTLVardef@10fa947org.highwire.dtl.DTLVardef@132a92dorg.highwire.dtl.DTLVardef@100e4a4_HPS_FORMAT_FIGEXP M_FIG C_FIG Central Picture O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/696292v1_ufig2.gif" ALT="Figure 2"> View larger version (21K): org.highwire.dtl.DTLVardef@1a2d3b4org.highwire.dtl.DTLVardef@f8f84borg.highwire.dtl.DTLVardef@17510bcorg.highwire.dtl.DTLVardef@9da763_HPS_FORMAT_FIGEXP M_FIG C_FIG NK cell profiling for treatment stratification in resectable NSCLC Central MessageTumor-infiltrating NK cell profiling identifies distinct immune phenotypes that can inform personalized treatment strategies in resectable NSCLC. Perspective statementAbundance of intratumoral stress-responsive NK cells predicts favorable outcomes after upfront surgery, whereas enrichment of adaptive and immunoregulatory NK cells suggests greater benefit from neoadjuvant chemoimmunotherapy. These findings support incorporating NK-cell profiling into preoperative decision-making to optimize therapy selection and balance risks in the high-risk surgical population.

immunology↗

bioRxiv2025

Organization of mouse prefrontal cortex subnetwork revealed by spatial single-cell multi-omic analysis of SPIDER-Seq

Deciphering the connectome, anatomy, transcriptome and spatial-omics integrated multi-modal brain atlas and the underlying organization principles remains a great challenge. We developed a Single-cell Projectome-transcriptome In situ Deciphering Sequencing (SPIDER-Seq) technique by combining viral barcoding tracing with single-cell sequencing and spatial-omics. This empowers us to delineate a integrated single-cell spatial molecular, cellular, anatomic and projectomic atlas of mouse prefrontal cortex (PFC). The projectomic and transcriptomic cell clusters display distinct modular organization principles, but are coordinately configured in the PFC. The projection neurons gradiently occupied different territories in the PFC aligning with their wiring patterns. Importantly, they show higher co-projection probability to the downstream nuclei with reciprocal circuit connections. Moreover, we integrated projectomic atlas with their distinct spectrum of neurotransmitter/neuropeptide and the receptors-related gene profiles and depicted PFC neural signal transmission network. By which, we uncovered potential mechanisms underlying the complexity and specificity of neural transmission. Finally, leveraging machine learning, we predicted neuron projections with high accuracy by combining gene profiles and spatial information. As a proof of concept, we used this model to predict projections of fear recall engram neurons. This study facilitates our understanding of brain multi-modal network and neural computation.

neuroscience↗

bioRxiv2025

Mitochondrial membrane junction-mediated ATP channeling drives activity-dependent glucose metabolism

Neurons and brown adipocytes rely on rapid ATP production from accelerated glucose metabolism to sustain bursts of activity upon stimulation, a process known as activity-dependent glucose metabolism. The first committed step in this pathway, the hexokinase I (HK1)-catalyzed phosphorylation of glucose, consumes ATP, raising the question of how this reaction can be accelerated when cytosolic ATP becomes limiting during stimulation. We identify Cell Cycle Exit and Neuronal Differentiation protein 1 (CEND1), expressed in both cell types, as a critical regulator of this process. Loss of CEND1 impairs activity-dependent glucose utilization, ATP generation, and stimulation-evoked activity both in vitro and in vivo. Mechanistically, CEND1 assembles a complex with HK1, voltage-dependent anion channel 1 (VDAC1), and adenine nucleotide translocase 1 (ANT1) at hemifusion-like membrane junction between the outer/inner mitochondrial membrane, channeling mitochondrially derived ATP directly to HK1. These findings uncover a previously unrecognized mechanism that sustains activity-dependent glucose metabolism, with broad implications for energy homeostasis in specialized cell types.

physiology↗

bioRxiv2025

Conformation-specific Antibody Deciphers K27-linked Ubiquitination in Chaperone-Mediated Proteostasis

Lysine 27 (K27)-linked polyubiquitination plays critical yet incompletely defined roles in proteostasis, innate immunity, and disease progression; however, investigations into this process have long been hindered by its extremely low abundance and the lack of conformation-specific enrichment tools. Herein, we describe the development of a long-sought conformation-specific antibody, K27-IgG, which can selectively recognize--among all ubiquitin chain types--the unique architecture of K27-linked polyubiquitin (K27-polyUb) characterized by a distinct buried K27-isopeptide bond, with high affinity (KD = 4.66 nM). This antibody was derived from synthetic antibodies initially generated via phage display, using chemically synthesized K27-linked diubiquitin (K27-diUb) as the antigen. High-resolution co-crystal structures uncovered the unique K27-diUb interface targeted by these sAbs. Subsequent reformatting of these sAbs into a full-length human immunoglobulin G (IgG) scaffold yielded K27-IgG, notably exhibiting markedly enhanced affinity without compromising selectivity. Using K27-IgG as a tool, we achieved sensitive detection and immunoprecipitation (IP) of endogenous K27-polyUb in cells, and delineated the intracellular interaction landscape of K27-polyUb through complementary proteomic approaches. Two key findings emerged: 1) The molecular chaperone DNAJB1 is a specific reader of K27-linked ubiquitin chains (but not other linkages) and that K27-polyUb chains themselves exhibit chaperone-like activity, suggesting a novel mechanism by which K27-polyUb regulates chaperone-mediated proteostasis; 2) The E2 enzyme UBE2Q1 assembles K27-diUb, identifying it as a potential writer for this ubiquitin chain topology. Collectively, this study establishes K27-IgG as a robust tool for deciphering the K27-linked ubiquitin code, thereby opening new avenues for investigating the biological functions of K27-linked polyubiquitination. HighlightsO_LIFirst K27-linkage conformation-specific antibody with nanomolar affinity overcomes a major barrier in the field. C_LIO_LIK27-IgG unlocks functional mapping of the K27 ubiquitin landscape under proteotoxic stress. C_LIO_LIMolecular chaperone DNAJB1 is a selective "reader" of K27-linked ubiquitin chains. C_LIO_LIK27 chains possess intrinsic chaperone activity, enabling protein refolding and suppressing aggregation. C_LIO_LIE2 enzyme UBE2Q1 is a "writer" that directly assembles K27-linked ubiquitin chains. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=116 SRC="FIGDIR/small/695067v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@113b980org.highwire.dtl.DTLVardef@1f7c1a0org.highwire.dtl.DTLVardef@c91656org.highwire.dtl.DTLVardef@1d9a507_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2025

High-Fidelity Tuning of Olfactory Mixture Distances in the Perceptual Space of Smell Through a Community Effort

A central goal in sensory science is to establish quantitative mappings between physical stimuli and perceptual responses. While such mappings are well characterized in vision and audition, they remain poorly defined in olfaction, limiting progress toward understanding the representations of smell. Predicting perceptual similarity between odor mixtures offers a promising route to formalize these relationships. To advance this effort, the DREAM (Dialogue for Reverse Engineering Assessment and Methods) Olfactory Mixtures Prediction Challenge assembled a curated, cross-study dataset describing the similarity of 507 mixture pairs and an unpublished test set of 46 mixture pairs. Teams competed to predict the perceptual similarity of mixture pairs, and then collaborated post-challenge to create an ensemble combining top-performing models that notably improves predictions over the existing state-of-the-art models. Moreover, ensemble model maintains high predictive accuracy in novel validation set. Our model provides a reproducible framework for neuroscientists, chemists, and engineers to compare odor mixtures and provides a foundation for future efforts towards better understanding the olfactory properties of mixtures.

neuroscience↗

bioRxiv2025

Gasdermin E couples mitochondrial damage to pyroptotic neurodegeneration in Parkinson disease

Parkinsons disease (PD) features progressive loss of nigrostriatal dopamine neurons, but how mitochondrial damage engages programmed cell death pathways remains unresolved. Here, we identify gasdermin E (GSDME), the caspase-3-activated executor of pyroptosis, as a critical mediator of neurodegeneration in toxin-based PD models. In primary neurons and SH-SY5Y cells, the mitochondrial complex I inhibitor MPTP/MPP triggered caspase-3 activation, GSDME cleavage, and lytic membrane rupture. Genetic silencing of Gsdme or its transcriptional regulator SP1 reduced neuronal death. In vivo, Gsdme deficiency preserved substantia nigra pars compacta dopaminergic neurons, improved motor performance, and mitigated anxiety- and depression-like behaviors after MPTP administration. Loss of Gsdme also dampened microglial and astrocytic activation and lowered proinflammatory cytokines in striatum and substantia nigra. Mechanistically, cleaved GSDME localized to mitochondria, disrupted membrane potential, increased reactive oxygen species, and precipitated organelle injury, thereby coupling mitochondrial dysfunction to pyroptotic cell death. These findings identify GSDME-mediated pyroptosis as a mechanistic link between mitochondrial toxicity and neuroinflammation in PD and nominate GSDME as a therapeutic entry point to slow disease progression. SignificanceHow mitochondrial injury kills dopamine neurons in Parkinsons disease is a central unresolved question. We show that the pyroptosis executor GSDME is required for neurodegeneration and neuroinflammation in MPTP models, mechanistically linking caspase-3 activation and mitochondrial damage to lytic cell death. Targeting GSDME may provide a strategy to protect vulnerable neurons in PD. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=191 SRC="FIGDIR/small/694264v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@15364e7org.highwire.dtl.DTLVardef@57b65org.highwire.dtl.DTLVardef@1e85108org.highwire.dtl.DTLVardef@1200d34_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsGSDME drives PD-linked neuronal loss. Silencing GSDME (or its transcriptional factor Sp1) ameliorates MPTP-triggered neuronal cell death. Genetic ablation of Gsdme is protective in the MPTP-induced PD mouse model. Gsdme-/-mice retain nigrostriatal DA neurons, show improved motor and affective behaviors, and exhibit reduced microglial and astrocytic activation and cytokines release upon MPTP treatment. Cleaved GSDME accumulates on mitochondria, collapses {Delta}{Psi}m, raises ROS, and links mitochondrial toxicity to pyroptosis, thus positioning GSDME as a tractable target to slow PD progression.

neuroscience↗

bioRxiv2025

A global deep-sea small protein atlas reveals a reservoir of noncanonical antimicrobial peptides

Small proteins encoded by small open reading frames (smORFs; [≤] 100 aa) represent a largely unexplored dimension of microbial diversity, especially in the deep sea. By analyzing 708 metagenomes from five major deep-sea biomes (hadal trenches, cold seeps, hydrothermal vents, abyssal plains, and seamounts), we constructed the Deep-Sea Small Protein Atlas, comprising 88.7 million smORFs with exceptional novelty and strong habitat specificity. Deep-learning predictions identified 5.47 million candidate antimicrobial peptides (c_AMPs), revealing a peptide space far larger and structurally distinct from known AMPs. Deep-sea c_AMPs are longer, enriched in nonpolar and acidic residues, and exhibit low charge and high intrinsic disorder, suggesting non-membranolytic modes of action. We synthesized 131 representative peptides, of which 87% were antimicrobial, with MICs as low as 1.25 M, broad-spectrum antibacterial and even antifungal efficacy, and minimal mammalian cytotoxicity. Transcriptomics, TEM imaging, and peptide-protein modeling showed that representative peptides preserve membrane integrity while disrupting intracellular processes such as translation and metabolism, supporting intracellular, non-lytic mechanisms. This work uncovers a vast reservoir of previously unrecognized deep-sea small proteins and structurally unconventional AMPs, providing a foundational resource for discovering next-generation peptide therapeutics.

microbiology↗

bioRxiv2025

A global atlas of deep-sea cold seep viruses uncovers extensive genomic novelty, pervasive viral dark matter, and biotechnological potential

Cold seeps are globally distributed deep-sea ecosystems harboring diverse chemosynthetic microbial communities, yet their viral components remain poorly understood. Here, we establish the Global Cold Seep Virome, a comprehensive catalog of 191,937 species-level viral operational taxonomic units (vOTUs) and 2.44 million viral protein clusters reconstructed from 314 metagenomes spanning 18 cold seep sites worldwide. Most vOTUs are distinct from those in existing environmental viromes, suggesting that cold seeps harbor a largely unexplored viral reservoir. Host prediction suggests diverse viral associations with key prokaryotes, including anaerobic methanotrophic archaea. Protein annotation reveals that these viruses encode widespread uncharacterized proteins and viral hallmark proteins with divergent physicochemical properties, potentially contributing to their ecological adaptability. We also identify putative auxiliary metabolic genes, anti-defense genes, and lysins, and experimentally validate representative anti-defense proteins and lysins with strong activities. This resource expands current knowledge of deep-sea viral diversity and provides a foundation for studying virus-host interactions, testing biogeochemical hypotheses, and exploring biotechnological potential in cold seep ecosystems.

microbiology↗

bioRxiv2025

Rapid ecosystem collapse and biofilter formation following seabed methane leakage

Globally, vast amounts of methane are trapped within subseafloor gas hydrates. Recent evidence suggests that climate- and human-induced perturbations can destabilize gas hydrates and trigger methane release, yet the response of deep-sea ecosystems to these changes remains poorly understood. Here we show multi-year in situ monitoring of seabed ecosystem following methane leakage induced by hydrate exploration activities. Within just two years, benthic microbial and eukaryotic diversity in the affected areas declined significantly, while microbial and macrofaunal abundance increased. Integrated geochemical and omics analyses reveal the rapid successional shift of seabed ecosystem to a novel chemosynthetic system. Aerobic methanotrophs (Methyloprofundus) co-established with unexpectedly fast growing anaerobic methanotrophic archaea (ANME-3), accompanied by a rapid recruitment of opportunistic polychaetes that bioirrigated the seabed to >50 cm depths. The active animal-microbe interactions sustained exceptionally high rates of methane oxidation that utilized diverse electron acceptors. We demonstrate that methane hydrate destabilization can trigger rapid collapse of native seabed ecosystem while driving the formation of an effective methane biofilter consuming this potent greenhouse gas much faster than previously estimated. Understanding seabed ecosystem response and feedback is critical for predicting benthic methane cycling under ongoing global change and for developing sustainable strategies for methane hydrate resource management.

ecology↗

bioRxiv2025

Comparative Assessment of Large Language Models for Microbial Phenotype Annotation

Large language models (LLMs) are increasingly used to extract knowledge from text, yet their coverage and reliability in biology remain unclear. Microbial phenotypes are especially important to assess, as comprehensive data remain sparse except for well-studied organisms and they underpin our understanding of microbial characteristics, functional roles, and applications. Here, we systematically assessed the biological knowledge encoded in publicly available LLMs for structured phenotype annotation of microbial species. We evaluated the performance of over 50 LLMs, including state-of-the-art models such as Claude Sonnet 4 and the GPT-5 family of models. Across phenotypes, LLMs reached accurate assignments for many species, but performance varied widely by model and trait, and no single model dominated. Model self-reported confidence is informative, with higher confidence aligning with higher accuracy, and can be used to prioritize phenotype assignment, effectively distinguishing between high-and low-confidence inferences. Overall, our study outlines the utility and limitations of text-based LLMs for phenotype characterization in microbiology.

bioinformatics↗

bioRxiv2025

Brain endothelial PRMT5-ANGPTL4 axis regulates cerebellar inhibitory synaptogenesis and motor coordination

Brain vasculature is essential for central nervous system function, but its specific roles in synaptic development and motor function regulation are poorly understood. In this study, we identify a cerebrovascular signaling axis wherein endothelial PRMT5 critically regulates inhibitory synaptogenesis and motor coordination. Cerebrovascular-specific deletion of Prmt5 gene leads to excessive inhibitory synaptic input onto Purkinje cells and progressive motor deficits in mice. Mechanistically, PRMT5 deficiency epigenetically upregulates the expression of the secreted factor ANGPTL4 through reduced symmetric dimethylation of H3R8 and H4R3, along with increased H3K9 acetylation at the Angptl4 promoter, thereby driving excessive inhibitory synaptogenesis onto Purkinje cells. Importantly, Angptl4 deletion in brain endothelium normalizes inhibitory synaptic input onto Purkinje cells and restores motor coordination in PRMT5-deficient mice. Together, these findings define the endothelial PRMT5-ANGPTL4 axis as a key regulator of cerebellar inhibitory circuitry and motor function, highlighting cerebrovascular mechanisms as potential therapeutic targets for motor coordination disorders. Teaser Cerebrovascular PRMT5 prevents excessive inhibitory synaptogenesis via epigenetic repression of Angptl4.

neuroscience↗

bioRxiv2025

Optimizing cytochrome P450 activity for quillaic acid biosynthesis in Saccharomyces cerevisiae

QS-21, a saponin extract from the Chilean tree Quillaja saponaria, is gaining popularity as a potent vaccine adjuvant, but its production is constrained due to its low natural abundance and complex chemical structure of the triterpenoid saponins, which hinder large-scale production through plant extraction or chemical synthesis. Microbial biosynthesis presents a promising alternative, with Saccharomyces cerevisiae emerging as a desirable host for triterpenoid production. A key step toward microbial QS-21 synthesis is the efficient biosynthesis of its aglycone core, the triterpenoid quillaic acid. However, its efficient production remains limited by challenges of cytochrome P450 enzyme (CYP450s) activity, including cofactor availability and electron transfer efficiency. To address this limitation, we applied a multi-faceted metabolic engineering strategy to optimise CYP450 activity, including CYP450 expression and cytochrome P450 reductase (CPR) selection. Additionally, aligning CYP450 expression with the ethanol phase, enhanced the metabolic flux toward quillaic acid synthesis, leading to an 85-fold increase in titre. Together, these strategies led to a quillaic acid titre of 385 {+/-} 14 mg/L in flask fermentation. Fed-batch bioreactor fermentations increased quillaic acid titre to 471 {+/-} 20 mg/L and significantly increased the selectivity for QA from 32.6% to 65.1% of the total triterpenoids produced. These findings demonstrate the effectiveness of enhancing CYP450 activity through targeted strategies and reveal potential bottlenecks in CYP450 expression, providing valuable insights for future optimization of triterpenoid production in yeast.

synthetic biology↗

bioRxiv2025

Fast and accurate tree of blobs reconstruction under the network multispecies coalescent

Hybridization between species is an important force in evolution, commonly modeled by the network multispecies coalescent. Reconstructing evolutionary histories under this model is computationally challenging, even for level-1 networks where hybridization events are isolated. Divide-and-conquer is a promising path forward, but current methods with statistical guarantees rely on an estimated tree of blobs (TOB) for the network, which compresses the non-tree-like parts into single vertices. TOB reconstruction is itself challenging, with the only available method TINNiK having time complexity O(n5 + n4k) for k genes and n species. Here, we present a new framework for scalable TOB reconstruction with statistical guarantees. Our approach operates by (1) seeking a refinement of the TOB and then (2) contracting edges in it. For step (1), we show that any optimal solution to Weighted Quartet Consensus is a TOB refinement almost surely, as the number of genes goes to infinity, motivating the use of methods, such as ASTRAL or TREE-QMC. For step (2), we show that applying the same hypothesis tests as TINNiK to just O(n) four-taxon subsets around each edge is sufficient for statistical consistency when the underlying network is level-1. Leveraging TREE-QMC for the first step gives our method time complexity O(n3k) and its name: TOB-QMC. On simulated data, TOB-QMC typically matches or exceeds TINNiK in accuracy while being more scalable. TOB-QMC also enables fast exploration of non-tree-like evolution, as demonstrated through re-analysis of three phylogenomic data sets. Lastly, our study clarifies the theoretical utility of quartet-based species tree methods in the context of hybridization, which is critical given the recent result that ASTRAL can be misleading.

bioinformatics↗

bioRxiv2025

Mapping neural subspace dynamics onto the structure of the mouse descending motor system

The motor cortex supports various cognitive and motor functions. To prevent interference between these processes, the associated neural dynamics may be organized into orthogonal subspaces. In this subspace model, activity in a movement-null subspace encodes internal processes, while activity in a movement-potent subspace relates to movements. The biological implementation of this model - how activity in different subspaces map onto neural circuits - remains unclear. Particularly, it is unknown whether different cell types, with specific connectivity patterns, preferentially contribute to specific subspaces. Here, we test whether the cell type that directly links motor cortex to motor centers in the medulla and spinal cord - lower layer 5b extratelencephalic neurons (L-ETN) - preferentially encodes activity contained in the movement-potent subspace. We performed cell-type-specific recordings in the motor cortex while mice performed a delayed-response licking task, and decomposed population activity into movement-null and movement-potent subspaces. We find that L-ETN activity spans both movement-null and movement-potent subspaces in a manner that could not be distinguished from the broader motor cortex population. Notably, downstream medullary circuits retain a subset of the movement-null dynamics contained in motor cortex, with select movement-null signals specifically filtered out. These results indicate that a distinct cortical output alone does not mediate the cancelation of null dynamics; movement-null computations are instead distributed across the descending motor hierarchy.

neuroscience↗

bioRxiv2025

Global Insights into Evolution and Adaptation in KPC and NDM Coproducing Carbapenem-Resistant Klebsiella pneumoniae.

ObjectivesThe worldwide dissemination of carbapenem-resistant Klebsiella pneumoniae co-producing KPC and NDM (KPC-NDM-CRKP) poses a substantial clinical challenge. MethodsThis study characterized 5 KPC-NDM-CRKP isolates from a tertiary hospital in southern China and integrated 460 global isolates genomes to demonstrate the population framework of this epidemic pathogen. Results5 clinical isolates were multidrug resistance, exhibiting high level resistance to first-line drugs including carbapenems and ceftazidime/avibactam. Globally, KPC-2-NDM-1 (50.3%) were the most common and an increasing trend of ST11-KL64 (20%) isolates carrying iucA and rmpA/A2. Resistance and virulence genes were positively associated with specific mobile elements including blaKPC-3 with Tn4401, iucABC with IncHI1B, iroBCDN with IncQ1. The phylogenetic analysis revealed distinct lineage-specific mutations and pan-genome enrichments synergistically promoted adaptive evolution: cluster 1 had membrane transport and secretion but enhanced immune evasion and horizontal gene transfer, cluster 3 adapted metabolically for nutrient-limited niches; cluster 4 reprogrammed metabolism for host adaptation, cluster 6 displayed membrane repair and reduced virulence (e.g., KC187). High-risk iucA/rmpA-positive isolates in cluster 2 acquired enhanced virulence and metabolic adaptive capacity through recombination hotspots (ABC transporters DdpABCD, efflux systems MdtABCD, metabolic enzymes XylB and MtlD, regulators BaeR and OmpR) and pan-genome enrichment (siderophore biosynthesis, toxin-antitoxin VapC and restriction-modification systems). Functionally, these traits correlated with high mucoviscosity, serum resistance, siderophore production and lower survival rates in G. mellonella that contribute to epidemiological success. ConclusionsThese findings demonstrated the discrete mutation, horizontal transfer, and accessory genome plasticity collectively drove the epidemiological success of KPC-NDM-CRKP.

microbiology↗

bioRxiv2025

AAV Kills Dividing Cells by Depleting PARP1 and Other DNA Damage Response Proteins

Recombinant adeno-associated virus (rAAV) is a replication-defective viral vector used in hundreds of human gene therapy trials, resulting in five FDA-approved therapies. Despite this success, rAAV-based gene therapies suffer from dose-limiting toxicities, resulting in several severe adverse reactions, including death. Previously, we discovered that rAAV rapidly kills mouse NPCs in vitro and in vivo. This vector contains a minimal genome comprised of 145-base pair inverted terminal repeats (ITRs) with a T-shaped hairpin structure that appears to be necessary and sufficient for this toxicity. However, the mechanism for AAV ITR toxicity is not known, and there have been few attempts to engineer ITRs to attenuate rAAV toxicity. In the current study, we explore the molecular mechanisms that drive dose-dependent rAAV toxicity in dividing human NPCs (hNPCs) and test whether disrupting these mechanisms mitigates this toxicity. Recombinant AAV infection induces aberrant cell cycle progression with activation of the ATM /CHK1/CHK2 pathway and expression of the DNA damage markers {gamma}H2AX and 53BP1. Affinity-based proteomics indicate that AAV ITRs bind to Poly-(ADP-Ribose)polymerase 1 (PARP1) and other DNA damage response (DDR) proteins involved in single-strand break repair (SSBR). Recombinant AAV infection attenuates poly-(ADP-ribose) (PAR) formation and mimics the antiproliferative effects of pharmacological PARP inhibitors used in cancer therapy. Moreover, treatment of hNPCs with PARP inhibitors is sufficient to reproduce many features of rAAV-induced toxicity. Finally, we demonstrate that eliminating the T-shaped hairpin within the AAV ITR reduces binding to SSBR proteins and the resulting rAAV toxicity. These findings suggest that rAAV infection induces replication stress and cell death in dividing hNPCs by functionally depleting PARP1 and other DDR proteins that are essential for DNA replication. This work fills substantial gaps in the understanding of the mechanisms of rAAV toxicity and has important implications for the development of safer rAAV-based human gene therapies. One Sentence SummaryThe rAAV genome binds to and depletes PARP1 and other SSBR proteins that are essential for DNA replication, resulting in DNA double stranded breaks, checkpoint activation, and cell death in dividing cells.

cell biology↗

bioRxiv2025

Multiplexed analysis of multicomponent biomolecular condensates without any tag

Biomolecular condensates, formed in the process of liquid-liquid phase separation (LLPS), play key roles in RNA metabolism and cellular organization. These dynamic assemblies often contain several components such as proteins and RNAs. Experimental methods to study biological condensates commonly involve fluorophore-labelling of the biomolecules, which may affect phase separation behavior and in addition cannot access dilute-phase components due to low dye concentrations. Here we introduce a non-invasive, multiplexed NMR approach that enables selective observation of multiple components in hydrogel-stabilized biphasic condensates without using tags. The introduced multiplexing filter combines enhanced spin-spin cross-relaxation in the condensed phase with diffusion and isotope filters to resolve signals from distinct protein pools from both dilute and condensed phases. We demonstrate the robust performance of this 1D 1H NMR experiment using biphasic samples containing condensates of FUS N-terminal domain, FUS full-length, and the multicomponent condensate formed by two intrinsically disordered regions of hnRNPC1 protein with highly overlapping resonances. Integrating the multiplexing filter into multidimensional experiments enables site-specific structural and dynamic insights from diverse protein populations, extending NMR applications in LLPS.

biophysics↗

bioRxiv2025

Prediction of TdP Arrhythmia Risk Through Molecular Simulations of Conformation-specific Drug Interactions with the hERG K+, NaV1.5, and CaV1.2 Channels

Unintended block of cardiac ion channels, particularly hERG (KV11.1), remains a key concern in drug development as disruption of ion channel function can lead to deadly arrhythmia. To assess proarrhythmic risk, we investigated how drugs interact with hERG in its open and inactivated states and whether drug interactions with other cardiac channels like NaV1.5 and CaV1.2 mitigate that risk. Using cryo-EM structures, we modeled open and inactivated conformations of these channels with Rosetta and AlphaFold. We then applied Site Identification by Ligand Competitive Saturation (SILCS), a physics-based pre-computed ensemble docking method, to predict drug binding affinities. SILCS leverages molecular simulation-generated free energy maps for high-throughput docking against hydrated lipid bilayer-embedded ion channel models. Bayesian machine learning was used to refine SILCS scoring using experimental IC50 values from 69 known hERG blockers outperforming Schrodinger Glide, AutoDock Vina, and OpenEye FRED drug docking predictions. Computed drug binding affinities for hERG and CaV1.2 channels were used to train machine learning models that successfully classified around 300 drugs from the CredibleMeds database. Cationic nitrogen SILCS fragment free energy scores were found to be top physical properties that are predictive of drug-induced Torsades de Pointes (TdP) arrhythmia risk. This approach, which relies on the predicted binding free energies and predicted physical properties of drugs rather than the chemical structure of the drugs themselves as features could be extended to facilitate the design of new drugs where rapid assessment of arrhythmia risk can be performed prior to experimental testing.

biophysics↗