Biology subjects

Wang, B.

Publications and source records attributed to Wang, B..

At least 19 recordsLinked to original sources

bioRxiv2026

In situ loading of biologics on and tissue redirection of circulating extracellular vesicles with an anchoring nanobody

Extracellular vesicles (EVs) are promising nanocarriers of therapeutic macromolecules, but ex vivo production, cargo loading and quality control constrains clinical translation. Here we demonstrate that NEV3, an EV-anchoring nanobody identified by phage display, binds EVs from multiple sources through interactions involving fibronectin and loads diverse proteins onto EVs, resulting in enhanced intracellular delivery and biological activities in vitro and in vivo. Conjugating NEV3 to target proteins hijacks circulating EVs, prolonging circulation and altering tissue distribution in vivo. When fused with an GFP nanobody or protein A, NEV3 enabled simultaneous capture and loading of circulating GFP or immunoglobulin G (IgG) antibodies on endogenous EVs with enhanced intracellular delivery in vitro and redistribution to liver in vivo. Intravenous protein A-NEV3 significantly reduced circulating IgG and anti-dsDNA antibodies in systemic lupus erythematosus mice with improved survival and reduced pathologies. Intravenous anti-transferrin receptor-protein A-NEV3 redirected circulating EVs to muscle and alleviated muscle pathologies in dystrophin-deficient mdx mice. Our study demonstrates that NEV3 enables in situ loading of protein therapeutics and tissue-specific delivery of circulating EVs, providing a modular strategy for loading cargo onto and redirecting circulating EVs in vivo.

bioengineering↗

bioRxiv2026

Heat-dependent engagement of a buried mitophagy motif in prohibitin 2

Mitophagy receptors are generally switched on by upstream enzymes rather than by the receptor itself. Whether a receptor can instead respond directly to a physical stimulus has not been established. Here we show that a second LC3-interacting region (LIR) in prohibitin 2 (PHB2) is regulated by temperature. It lies in a marginally stable helix that holds its two anchor residues about 5 angstrom apart, whereas a bound LIR spans about 9 angstrom. Replica-scaling simulations showed that this helix, but not a matched control from the same protein under identical scaling, samples that geometry; purified PHB2 bound ATG8-family proteins only at 313 K and above. Substitutions designed from this geometry to stabilise (K253A/R255A) or destabilise (I254G) the helix altered binding, mitochondrial recruitment and respiration in PHB2-null cardiomyocytes. Mice carrying the stabilising substitutions in cardiomyocytes sustained greater cardiac injury during heat stroke despite matched thermal load and comparable systemic injury. Motif accessibility may therefore be a regulated variable rather than a fixed property of a fold.

molecular biology↗

bioRxiv2026

Dynamic merging of enhancer- and promoter-associated assemblies is coupled to transcriptional bursting

Classical models attribute distal enhancer function to chromatin looping, whereas emerging models propose that spatially organized assemblies of transcriptional regulators also facilitate enhancer-promoter communication. To investigate how these processes relate to transcription, we developed an endogenous-tagging-based four-color live-cell imaging platform and an integrated quantitative analysis pipeline in mouse embryonic stem cells (mESCs), enabling simultaneous visualization of regulatory assembly dynamics, chromatin organization and transcriptional bursting at the endogenous Sox2 locus. We find that the pluripotency transcription factor OCT4 and the coactivator BRD4 form numerous spatially distinct but dynamically interacting assemblies. At non-bursting Sox2 alleles, the promoter and the distal Sox2 enhancer SCR occupy distinct assembly environments, with stronger BRD4 association at the SCR than at the promoter. At bursting Sox2 alleles, transcription is coupled to transient merging and partial overlap of enhancer- and promoter-associated assemblies, with the SCR, promoter and nascent RNA frequently sharing OCT4/BRD4-enriched assembly environments across a broad range of SCR-promoter distances. Pharmacological perturbation of bromodomain-dependent BRD4 function preferentially suppresses long-duration, high-amplitude bursts. Together, our findings support a model in which transcriptional bursting is coupled to the dynamic reorganization and merging of enhancer- and promoter-associated regulatory assemblies, linking chromatin-looping and assembly-based views of enhancer-promoter communication.

molecular biology↗

bioRxiv2026

Acetylation of NDUFA13 at K7 Senses OXPHOS Dysfunction to Disrupt Prohibitin Scaffolds and Drive Cristae Remodelling in Heart Failure

Mitochondrial cristae disintegration is a hallmark of heart failure, yet how oxidative phosphorylation (OXPHOS) dysfunction triggers this structural collapse remains unclear. Here we identify acetylation of the complex I subunit NDUFA13 at lysine 7 (K7) as a metabolic sensor coupling OXPHOS dysfunction to cristae remodelling. OXPHOS inhibition drove NDUFA13-K7 hyperacetylation, inducing conformational compaction and translocation to the intermembrane space. Acetylated NDUFA13 competitively engaged PHB2 through its coiled-coil domain, displacing PHB1 and disassembling prohibitin scaffolds. The acetylation-mimetic NDUFA13-K7Q induced cristae fragmentation in vitro, and cardiomyocyte-specific K7Q knock-in mice showed accelerated mortality and cristae loss under pressure overload, accompanied by impaired TCA cycle flux, defective fatty acid oxidation and selective depletion of polyunsaturated cardiolipins. These findings establish NDUFA13-K7 acetylation as a reversible switch converting bioenergetic failure into pathological cristae remodelling and metabolic reprogramming, highlighting therapeutic potential for targeted deacetylation.

cell biology↗

bioRxiv2026

High-dimensional hippocampus representation facilitates learning of low-dimensional abstract representation and supports generalization

Semantic knowledge encompasses facts, concepts, and their relationships. Recent work has proposed that some forms of semantic knowledge could be encoded in low-dimensional neural representations, such as the abstract, disentangled representational geometries observed in many cognitive brain areas. Experimental work has shown that hippocampal (HPC) lesions impair the formation of flexible and generalizable semantic knowledge. However, HPC representations are often high-dimensional and sparse. How can these representations contribute to the formation of low-dimensional abstract representation across these cognitive cortical areas? Here, we reconcile these observations using multiregional neural network models. Modeling HPC as a sparse, decorrelating autoencoder, we show that its high-dimensional representations promote the robust and efficient formation of low-dimensional abstract representations in downstream regions such as prefrontal cortex. This effect is most pronounced when the geometry of sensory inputs is misaligned with the geometry of desired outputs, requiring a more complex input-output transformation. Mathematical analysis shows that hippocampal expansion recoding suppresses misleading low-dimensional input structure and reshapes the loss landscape of downstream networks, allowing abstract semantic geometry to emerge reliably. The resulting abstract representations provide an inductive bias for sample-efficient learning of novel semantic-to-action mappings. Finally, we show that consolidating hippocampus-dependent representations into a hippocampus-independent pathway improves out-of-distribution generalization based on input structure. Together, these results suggest a circuit mechanism by which high-dimensional hippocampal representations can support, rather than oppose, the emergence of low-dimensional abstract representations.

neuroscience↗

bioRxiv2026

Scalable Enzyme Reaction Retrieval Enables Metagenomic Biocatalyst Discovery

Enzyme catalyzed reactions drive metabolism and enable diverse applications in biotechnology and sustainable synthesis, but assigning catalytic functions to uncharacterized enzymes and finding enzymes for target reactions remain major challenges. Despite recent advances in machine learning, translating enzyme function prediction into systematic discovery across the vast space of uncharacterized proteins and biochemical reactions remains challenging. Here we present EzHit, a lightweight framework for bidirectional enzyme reaction retrieval. Across enzyme annotation, orphan-reaction retrieval and family-specific fine-tuning benchmarks, EzHit achieved strong top-ranked performance and outperformed representative enzyme reaction matching baselines. We further show that Mahalanobis distance based geometric confidence provides more useful reliability estimates than probability-derived uncertainty metrics or evidential learning, enabling confidence-aware prioritization of high scoring candidates. Owing to its efficiency, EzHit was applied to a nearly trillion-scale OMG_Prot50 with RHEA screen, yielding 8.20 billion retained enzyme reaction associations across 30.27 million predicted enzyme sequences. Experimental validation further confirmed the activity of EzHit prioritized metagenomic enzyme candidates for a sparsely annotated reaction. Together, these results establish EzHit as a scalable framework for enzyme annotation, reaction-guided mining and biocatalyst discovery

bioinformatics↗

bioRxiv2026

A high-resolution protein-RNA binding atlas for structure-aware interaction prediction and post-transcriptional regulatory modeling

RNA-binding proteins (RBPs) control post-transcriptional gene expression by regulating RNA processing, localization, stability, and translation. However, our understanding of RNA regulation remains limited by the resolution, scale, and uniformity of available RBP binding maps. Here we introduce eclair CLIP (ecCLIP), a high-throughput CLIP-seq platform that combines endogenous protein tagging for uniform affinity capture with ligation-free library preparation to generate high-resolution RNA-protein binding profiles. We applied ecCLIP to 67 endogenously tagged RBPs in HEK293T cells, generating a high-quality transcriptome-scale atlas that recovered known binding preferences and captured post-transcriptional regulons linked to RNA half-life. To test the utility of the atlas, we incorporated ecCLIP into Borzuki, a Borzoi-derived sequence-to-function model trained on complementary RNA degradation, expression, CLIP, and Perturb-seq data. Inclusion of ecCLIP data improved RNA half-life prediction and assessment of 3' UTR variant effects on RNA stability, demonstrating that our atlas helps capture RNA dynamics. To directly model the cis-regulatory grammar underlying these RBP-RNA interactions, we developed Pythia, a structure-aware neural network architecture that incorporates context-free grammar-inspired fixed convolutions to explicitly encode RNA base-pairing features. Pythia predicted RBP binding from sequence and structural context and decomposed predictions into sequence- and structure-dependent components. We tested this decomposition for five RBPs using massively parallel reporter CLIP (MPRC) binding assays in cells, using synthetic RNA libraries containing mutations designed to preserve or disrupt predicted RNA structures across nominated binding sites. We used the same MPRC strategy to confirm allele-specific binding effects for variants prioritized by Pythia. Together, ecCLIP and Pythia provide a resource for structure-aware decoding of RNA-protein interaction grammar and interpretation of post-transcriptional regulatory variation.

genomics↗

bioRxiv2026

Ambient-Condition Visualization of Metalloenzyme Reactive Intermediates Enabled by the SHINERS Paradigm

Reactive metal-oxygen intermediates are central to metalloenzyme catalysis, yet their low populations and short lifetimes make vibrational characterization under aqueous reaction conditions challenging. Here, we establish shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) as a powerful vibrational approach for visualizing reaction-associated metal-ligand signatures of reactive metalloenzyme states. Across the heme and non-heme iron enzymes TauD, VioC, CYP119, and TqaLNc, isotope-sensitive features provide vibrational information on reactive coordination states. In TauD and VioC, isotope-sensitive features provide vibrational characterization of Fe(IV)=O intermediates. In CYP119, an isotope-sensitive Fe(IV)=O vibration is assigned to P450 Compound I generated by m-CPBA, including under lauric-acid turnover conditions. Most notably, in TqaLNc, combined 18O- and 15N-sensitive vibrational responses support formation of the proposed (R)HN-Fe(IV)=O coordination state and the dynamic-coordination mechanism underlying selective C-N bond formation. These results demonstrate that SHINERS can serve as a powerful technique for the in situ vibrational visualization of reactive intermediates and their coordination states in metalloenzyme catalysis.

biochemistry↗

bioRxiv2026

A synthetic PGC1α co-activator reprograms microglial immunometabolism to preserve cone function in retinal degeneration

Retinitis pigmentosa (RP) is genetically heterogeneous, yet initiating mutations converge on primary rod degeneration followed by cone dysfunction and loss. Activated microglia are implicated in this secondary phase, but whether selective immunometabolic reprogramming of microglia preserves retinal function remains unknown. In human iPSC-derived microglia and retinal CD11b cells, PGC1 induction suppressed LPS-driven interferon signaling and cytokine release, yet Seahorse analysis and isotopologue tracing showed that energy metabolism remained altered. We therefore fused PGC1 to a multivalent p65-HSF1 module, yielding ~2.5-fold higher nuclear receptor output than native PGC1 and coordinated engagement of oxidative and anti-inflammatory programs in mouse retinal CD11b cells. Microglia-restricted expression in humanized RHOP347L mice preserved photopic responses through six months, increased retinal thickness and promoted ramified subretinal IBA1 morphology. Microglial immunometabolism thus represents a potentially genotype-independent neuroprotective target in RP, and engineered PGC1 co-activators provide a means to sustain oxidative metabolism under inflammatory pressure.

immunology↗

bioRxiv2026

CD24-dependent innate immune checkpoint targeting chimera disrupts TGF-β-driven immunosuppression to enhance anti-tumor therapy

The immunosuppressive tumor microenvironment (TME) poses formidable challenges for cancer immunotherapies. Among the complex TME landscape, the cytokine TGF-{beta}1 is an attractive soluble target for reinvigoration of anti-tumor immunity due to its pivotal function in immune cell suppression, extracellular matrix remodeling, and epithelial-to-mesenchymal transition (EMT) promotion, while immune checkpoint receptors exemplified by PD-1 and CD24 are promising surface targets. Though adaptive immune checkpoint inhibition is well established in clinical practice, TGF-{beta} blockade or innate immune checkpoint blockade is yet to be harnessed for tumor treatment. Here, leveraging CD24 overexpression on multiple tumor tissues and its unique recycling kinetics, we designed an innate Immune Checkpoint TArgeting Chimera (ICTAC) G01, a bifunctional CD24 antibody-TGF-{beta}1 receptor fusion protein that disrupts TGF-{beta}1 signaling by TGF-{beta}1 degradation instead of simple blockade and simultaneously inhibits the "don't eat me" CD24 signaling. We demonstrated that G01 effectively suppressed TGF-{beta}1-Smad signaling, reversed the EMT, and attenuated fibrotic collagen deposition. Additionally, it antagonized CD24 signaling to unleash robust antibody-dependent effector activity, further reprogramming the immunologically cold TME toward inflammatory phenotype. By selectively targeting malignant cells while sparing CD24-expressing B cells, G01 demonstrated a favorable safety profile. Notably, in patient-derived tumor fragments (PDTFs), G01 also inflamed the TME, underscoring its translational potential. Together, these results establish ICTAC as an effective strategy for tumor-specific receptor-mediated extracellular protein depletion, which supports its application for reversing TGF-{beta}1; and innate immune checkpoint-mediated tumor immunosuppression by concurrent targeting of both surface and soluble tumor-promoting factors.

immunology↗

bioRxiv2026

Structural basis for differential inhibition of THIK1 by chemically related inhibitors

TWIK-related halothane-inhibited potassium channel 1 (THIK1) is a two-pore domain potassium (K2P) channel highly expressed in microglia that contributes to microglial homeostasis and neuroinflammatory responses. Pharmacological inhibition of THIK1 suppresses tonic K+ currents and attenuates NLRP3-dependent IL-1{beta} release, highlighting THIK1 as a potential therapeutic target for neuroinflammatory disorders. However, the structural basis of THIK1 inhibition remains unclear. Here we report cryo-electron microscopy (cryo-EM) structures of full-length human THIK1 in complex with C101248, a commercially available tool compound, and CVN293, a clinical-stage inhibitor that has completed Phase I evaluation. The two inhibitors occupy a similar site within the inner vestibule formed by TM2 and TM4 beneath the selectivity filter. Consistent with their closely related chemical scaffolds and shared binding site, both inhibitors remodel the Y273 inner gate but differ in their effects on the C-terminal gate. Electrophysiological analyses further demonstrate that the C-terminal gate contributes differently to inhibition by the two compounds. Together, our findings show how chemically related inhibitors exert different effects on THIK1 despite engaging a common binding site.

biophysics↗

bioRxiv2026

An integrated platform for genome-wide functional analysis in Aspergillus niger through Ac/Ds insertion profiling and metabolic modeling

Genome-scale metabolic models guide rational strain engineering, while high-throughput insertional mutagenesis enables systematic investigation of gene function and condition-dependent growth requirements. However, a platform integrating high-density transposon insertion sequencing with matched stoichiometric, thermodynamic, enzyme-constrained and combined metabolic models has not, to our knowledge, been reported in Aspergillus. Here, we establish a unified experimental and computational platform in Aspergillus niger ATCC1015 by combining curated metabolic reconstruction, Ac/Ds transposon mutagenesis and machine-learning-based essentiality prediction. Our stoichiometric reconstruction, FBA1015, expands reaction coverage and compartmental resolution beyond four published reconstructions. From FBA1015, we developed three models sharing its biochemical network: GECKO light with enzyme-capacity constraints, TFA with thermodynamic constraints and ecTFA combining both. FBA1015 and its derivatives performed competitively in phenotype benchmarks, with added constraints improving agreement with measured growth and gas exchange. Insertion libraries grown in rich medium, glucose or xylose achieved genome-wide densities of one distinct site per 21--112bp across individual libraries. A machine-learning classifier integrated insertion patterns and gene structure to predict essentiality across 11,111 genes. Applying a stringent consensus criterion identified 709 genes predicted essential on both glucose and xylose as sole carbon sources, and 91 predicted essential on one but nonessential on the other. Integration with simulated gene deletions prioritizes candidate genes and testable pathway hypotheses, connecting high-throughput genetic screening with mechanistic analysis for fungal functional investigation and strain engineering.

microbiology↗

bioRxiv2026

MINT infers the latent single-cell spatial transcriptome from paired histology

Sequencing-based spatial transcriptomics captures transcriptome-wide molecular information, yet the corresponding cell-resolved tissue map remains incomplete. Histology records dense cellular morphology, tissue architecture and local context. Here, we present MINT (Morphological Integrative Network for Transcriptomics), which combines this latent cellular organisation with sample-specific spatial measurements to infer tissue-wide, cell-resolved transcriptomes without an external single-cell reference. MINT reconstructs expression from sparse Slide-tags profiles across unmatched adjacent sections; its shared nucleus-centred representation also resolves pooled Visium measurements into cell-level profiles. MINT improved Slide-tags alignment and expression recovery under controlled nuclear loss and cross-section perturbation. It also outperformed reference-free Visium disaggregation methods against Xenium ground truth and was validated with Visium HD sequencing. In human lung adenocarcinoma, MINT reconstructed the tumour immune microenvironment cell by cell and resolved tertiary lymphoid structures and their maturity. These results establish paired histology as a quantitative, sample-intrinsic complement to molecularly rich but cellularly incomplete spatial-transcriptomic assays.

bioinformatics↗

bioRxiv2026

Single Amino Acid Disease Mutations Act as Genetic Glues to Drive Neo-substrate Degradation

Disease-associated missense mutations are well known to affect protein turnover by either impairing substrate-ubiquitin ligase interactions or inducing misfolding-triggered protein clearance. Whether such mutations can drive gain-of-function in substrate-selective protein degradation remains under-explored. Here, we develop a tri-color global protein stability system to profile mutational effects across the intrinsically disordered regions (IDRs) of human transcription factors. Unexpectedly, we identify single amino acid substitutions that create functional short linear motif degrons to drive targeted protein degradation independently of protein quality control. These disease variants are exemplified by the gain of an FRY-like degron in GATA2, whose deficiency leads to impaired immune function. Structural analyses reveal that the substituted residue enables neomorphic interaction between the transcription factor and the KLHL15 E3 ligase by complementing their otherwise suboptimal interface. The prevalence of such glue-like mutations beyond transcription factors suggests that quasi-degrons are widespread in protein IDRs and can be functionalized by simple mutations, a finding that may inform the rational discovery of molecular glue degraders.

molecular biology↗

bioRxiv2026

The transcription factor THAP11 is a general regulator of early embryonic polarization

During mouse embryogenesis, three sequential waves of cell polarization occur in the 8-cell-morula trophectoderm (TE), E3.5-E4.5 primitive endoderm (PrE), and E4.5-E5.5 epiblast (Epi), driving cell fate determination and morphogenic events that lay the foundation for embryonic development. However, it is not clear whether a general regulator that functions in all three waves of polarization exist. Here, we demonstrate that transcriptional factor THAP11 is such a general regulator. Using a novel mouse model combining genetic knockout and an inducible degron system, we demonstrate that stage-specific acute THAP11 depletion causes the failure of the three waves cell polarization, resulting in defective blastocyst formation, PrE maturation, and Epi lumenogenesis, respectively. Mechanistically, THAP11 does not directly regulate pluripotency genes but drive polarization through both stage-specific and conserved chromatin-bindings that commonly activate polarity programs, including Golgi vesicle transport. THAP11 activates polarity genes by promoting chromatin accessibility at their promoters. THAP11, together with stage-specific regulators, sequentially paces the timing of cell polarization. Collectively, our study establishes THAP11 as a general regulator of embryonic morphogenesis.

developmental biology↗

bioRxiv2026

RfaH licenses RNA polymerase for long-range transcription

Processivity is essential for gene expression: Escherichia coli RNA polymerase (RNAP) must transcribe 10+ kbp operons without failure, yet backtrack-induced long-lived pauses threaten premature termination. Gre factors stimulate transcript cleavage to rescue backtracked RNAP, whereas NusA and NusG, which bridge the expressome, respectively stimulate and suppress pausing. How they cooperate to secure full-length transcription is unclear. Using high-throughput magnetic tweezers, we reconstitute ops-induced pausing, showing that sequence context sets pause occupancy. RfaH, a NusG paralog recruited at ops and essential for long virulence operons, loads onto ops-paused RNAP by two pathways: one permitting immediate escape, the other requiring GreA rescue. We find that both NusG and RfaH nullify NusA's pause-stimulating effect, RfaH sustaining runs four times longer than NusG and replicating its role in vivo, where RfaH depletion leads to conjugation failing. This work provides the foundation for dissecting virulence operon expression and its therapeutic targeting.

biophysics↗

bioRxiv2026

Parallel Arg/N-degron recognition systems regulate coenzyme A biosynthesis

Coenzyme A (CoA) is an essential metabolic cofactor whose biosynthesis is controlled by pantothenate kinases (PANKs), the rate-limiting enzymes in CoA synthesis. Although CoA production is extensively regulated, whether PANK abundance is controlled by selective protein degradation remains unknown. Here, we identify PANK1{beta} and PANK3 as substrates of the Arg/N-degron pathway. Two mechanistically distinct E3 ligase systems, UBR4-KCMF1 and MKLN1-CTLH, independently converge on a common N-terminal MK Arg/N-degron to promote PANK degradation and restrict CoA biosynthesis. UBR4-KCMF1 recognizes the MK Arg/N-degron through KCMF1 ZZ domain, whereas CTLH complex employs the B30.2-domain proteins RanBP9 and RanBP10 as previously unrecognized Arg/N-degron recognins. Structural, biochemical, and cellular analyses demonstrate that RanBP9 and RanBP10 recognize both Met-X and canonical Arg/N-degrons through their B30.2 domains, using a mechanism distinct from canonical UBR proteins. Together, these findings establish a new branch of the mammalian Arg/N-degron pathway and reveal ubiquitin-dependent control of PANK abundance in CoA homeostasis.

molecular biology↗

bioRxiv2026

A Synthetic Archaeal Lipid Analog Enables Quantification of Substrate, Products, and Intermediates in the Tetraether Synthase Reaction

Glycerol dibiphytanyl glycerol tetraether (GDGT) and macrocyclic diether lipids (mAG) are unique membrane lipids predominantly found in archaea. Both lipids are composed of the same structural components: polar headgroups, glycerol backbones, and ether-linked 40-carbon biphytanyl chains. Tes, a member of the radical S-adenosylmethionine enzyme superfamily, synthesizes the biphytanyl chain by catalyzing carbon-carbon (C-C) bond formation between the terminal carbons of two phytanyl chains of the saturated diether lipid substrate. The coupling between the termini of two phytanyl chains on one glycerophospholipid yields mAG, whereas two couplings between the phytanyl termini of two glycerophospholipids yield GDGT. Quantification of the products and presumed intermediates formed during this multistep reaction has been challenging using mass spectrometry due to the lack of appropriate standards for each species. Herein, we designed and synthesized a diether lipid substrate analog containing a fluorescent/UV-visible tag linked to the headgroup, enabling the quantification of each species formed during a Tes reaction. Importantly, under laboratory conditions at 45 degrees C, we report that GDGT and mAG are initially formed in a 1:1.65 ratio, which differs considerably from the previously assumed ratio.

biochemistry↗