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The INO80-EEN complex prevents genomic rearrangements at protein coding genes regions

Plants are continuously exposed to a myriad of DNA-damaging agents, including environmental cues such as sunlight. At the cellular level, plants respond to DNA damage by activating DNA damage response (DDR) pathways, in which chromatin remodelers play an important role. Among them, the evolutionary conserved INO80 complex (INO80c) has been shown in Arabidopsis to play a key role in DDR, notably by positively regulating Homologous Recombination (HR). Arabidopsis EIN6 ENHANCER (EEN) is the homolog of Yeast INO EIGHTY SUBUNIT 6 and interacts with the N-terminal region of INO80 in the INO80c. Using plant phenotyping, cellular and molecular biology, and third-generation sequencing technology we investigated how INO80 and EEN regulate plant development and genome integrity. We uncovered new roles for INO80 and EEN in plant growth and for INO80 in fine tuning endoreduplication. In addition, linear genome analysis revealed an important and unexpected function for the INO80-EEN complex in preventing Protein Coding Genes (PCGs) from structural rearrangements in somatic tissue and upon exposure to UV-B. Therefore, our results shed new light on the previously overlooked roles of INO80 and EEN in protecting genome integrity at PCGs.

plant biology↗

Fluorometric DNA Polymerase Activity Assay for Resource-Limited Enzyme Manufacturing

BackgroundDNA polymerase activity assays are required for enzyme quality control in biotechnology and diagnostics, but standard methods rely on specialist reagents, radioactivity and other hazardous materials, or real-time PCR instruments that are not widely accessible in resource-limited settings. This constrains local production of high quality, validated reagents and increases dependence on imported enzymes. MethodsBased on experiences derived from partnerships with scientists in several low and middle-income countries (LMICs) and stakeholder consultations, we adapted a commercial EvaGreen-based fluorometric DNA polymerase activity assay for isothermal operation using minimal equipment. Assay conditions were optimized using Design of Experiments (DOE) methodology, varying temperature, reaction volume, and MgCl2 concentration. To address reagent cost and supply-chain constraints, we developed detailed protocols for in-house synthesis of the off-patent AOAO-12 DNA dye (sold commercially as EvaGreen) and generation of single-stranded DNA templates via asymmetric PCR. ResultsOptimized isothermal assay conditions (40{degrees}C, 7.75 mM MgCl2) reliably quantified activity across multiple DNA polymerase families. In-house synthesized AOAO-12 dye exhibited comparable DNA-binding performance to commercial alternatives (R{superscript 2} = 0.95), reducing costs by more than an order of magnitude when normalized to working concentrations, enabling assay costs of approximately {pound}0.001 per reaction. The assay is effective across multiple polymerases (Bst-LF, OpenVent, Taq, Q5) and is compatible with both plate readers and qByte, a low-cost, open-source fluorometric device. ConclusionsThis stakeholder-informed assay provides an accessible, cost-effective solution for DNA polymerase quality control in resource-limited settings. The combination of optimized commercial protocols and in-house reagent synthesis offers flexibility for different resource contexts, potentially improving access to molecular biology tools globally.

biochemistry↗

A metagenomic thermostable monomeric meganuclease with novel specificity and unique palindromic 3-prime overhangs

As an alternative to historical enzyme isolation, metagenomic databases (e.g. MGnify) provide information on vast unculturable microbial diversity, especially from extreme environments, and constitute an enormous source of functional proteins. Conservative mining of these data by close sequence homology alone tends to identify merely different versions of known enzymes. Here we present a discovery strategy of meganucleases based on wider capture of less homologous enzymes with new function in metagenomic databases, incorporating metadata with homology, relying on cell-free expression to bypass host incompatibility and the need for purification, along with using deep sequencing for experimental assessment of substrate specificity and cleavage pattern, circumventing classical gel-based profiling. Specifically, we discovered the temperature-stable (>55{degrees}C), intron-encoded LAGLIDADG meganuclease I-MG11 that recognizes a 17 base pair sequence to generate unique 4 base pair palindromic 3'-overhangs -- the first monomeric meganuclease to produce such overhangs. Co-folding models of I-MG11 bound to DNA provide a structural context for enzyme-DNA interactions, highlighting differences from other monomeric LAGLIDADG meganucleases (e.g. I-SceI) shaped by InDels (insertion-deletions) in the DNA binding region that may cause specificity changes. Our strategy streamlines bona fide identification and annotation of meganucleases, while the unique properties of I-MG11 expand the molecular biology toolbox. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=31 SRC="FIGDIR/small/712669v1_ufig1.gif" ALT="Figure 1"> View larger version (11K): org.highwire.dtl.DTLVardef@199394aorg.highwire.dtl.DTLVardef@806490org.highwire.dtl.DTLVardef@14a533aorg.highwire.dtl.DTLVardef@9e13db_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

GROQ-seq Datasets Across Transcription Factors (LacI, RamR, VanR), T7 RNA Polymerase and TEV Protease

Predicting any proteins function from its sequence alone would be a significant breakthrough in molecular biology. Although machine learning approaches have sought to tackle this, their limited generalizability reflects the absence of sufficiently large, open, diverse, and unified datasets. To address this data gap, we developed a high-throughput experimental platform called GROQ-seq (Growth-based Quantitative Sequencing). In GROQ-seq, a proteins function can be linked to a sequencing-based readout that enables scalable characterization of large variant libraries in Escherichia coli. Here, we present pilot datasets demonstrating its performance across three distinct protein function classes: transcription factors, polymerases, and proteases. The objective of this report is to present the datasets and to provide users with a clear and transparent characterization of their properties, including both the strengths and limitations.

bioengineering↗

EasyCAPS: A web tool for restriction-based genotyping and rational CRISPR-Cas9 donor design

Tracking Single Nucleotide Polymorphisms (SNPs) following CRISPR-Cas9 genome editing is a critical yet often labor-intensive step in modern genetic research. Although Sanger sequencing is the conventional method for definitive confirmation, it typically requires substantial time to generate results. In contrast, PCR-based restriction methods like CAPS (Cleaved Amplified Polymorphic Sequence) and dCAPS (derived CAPS) offer rapid and cost-effective alternatives. However, existing dCAPS primer design tools suffer from significant limitations and were largely developed for tracking polymorphisms in plant genomes. Concurrently, CRISPR-Cas9 gene editing requires strategies to prevent the re-cleavage of the edited allele, typically involving the modification of the Protospacer Adjacent Motif (PAM). To address these challenges, we developed EasyCAPS, a web-based tool that integrates dCAPS primer design with advanced functionalities for CRISPR experiments. EasyCAPS overcomes the shortcomings of previous software by enabling restriction enzyme pre-selection and optimizing designs for complex DNA sequences. Its key innovation is the "Hiding PAM" feature, which designs synonymous mutations to mask the Cas9 recognition site while accounting for codon usage bias, thereby facilitating one-step allelic exchange. The utility of the tool was demonstrated through practical applications targeting the HTA1, PHO84, and CAT5 genes, significantly accelerating both genotyping and gene editing processes. We conclude that EasyCAPS is an accessible solution that effectively streamlines molecular biology workflows.

genetics↗

Toward a networked central dogma: protein specificity reshapes molecular encounters across evolution

Since its formulation in 1958, the Central Dogma has provided the organizing framework for molecular biology, describing the informational relationships among DNA, RNA, and protein. Yet, the framework ends at protein synthesis: what proteins do after they are made, how their catalytic specificities determine which molecules actually meet inside the cell, lies beyond its scope. Using a zero-parameter physical model applied to three phylogenetically distant species, we show that physical encounter frequency and metabolic flux are decoupled: raw collision rates predict reaction importance only weakly and show no consistent link to gene essentiality. Enzymatic selectivity bridges this gap through three distinct, species-conserved rescue patterns that persist across more than a billion years of evolution. The cells most critical metabolic hubs are, paradoxically, its physically least conspicuous ones-- rescued from the collision background by enzymatic precision alone. We term this downstream, measurable layer the Networked Central Dogma: a complement to the classical schema that connects gene expression to the physical organization of cellular chemistry.

evolutionary biology↗

Multiplex PCR based Detection Methods of Common Plant Transgenes

Accurate verification of transgenic plant materials is essential for maintaining scientific integrity and ensuring experimental reproducibility. As the number and diversity of transgenic constructs continue to expand, there is a growing need for practical and scalable methods that enable routine confirmation of transgene presence and identity. Reliable detection systems are particularly important for laboratories handling large numbers of genetically modified lines or distributing materials across research groups. To address this need, we developed two complementary methods for efficient detection of commonly used transgenes. The first method, fDET, is a higher-throughput system capable of simultaneously detecting 15 transgenes and three endogenous genes in a single multiplex PCR reaction followed by capillary electrophoresis. This approach provides rapid, high-resolution detection suitable for high-volume or time-sensitive applications. The second method, DET, offers a more accessible workflow that detects 10 transgenes and one endogenous gene using four multiplex PCR reactions followed by agarose gel electrophoresis. Because DET requires only standard molecular biology equipment, it can be readily implemented in a wide range of laboratory environments without specialized instrumentation. Together, these methods provide flexible and practical solutions for verifying the genetic status of both transgenic and non-transgenic plant materials. By enabling efficient and comprehensive transgene detection, they support reproducible experimentation, facilitate quality control in plant research, and streamline the management and exchange of genetically modified lines. These approaches contribute to more reliable and transparent use of transgenic resources across the plant science community.

plant biology↗

PhAGE Enables One-Step Genome Integration of Large DNA Fragments in Escherichia coli

Escherichia coli is a well-established model organism in molecular biology and biotechnology. Despite its long history as a laboratory workhorse, the efficient single-step chromosomal integration of large DNA fragments remains a challenge. Currently known methods are either simple but have limitations on insert size, or flexible but laborious requiring plasmid construction or multi-step procedures. Here, we present PhAGE (Phage-Assisted Genome Engineering), which enables the integration of [~]20 kb DNA fragments into E. coli genome within a single day. PhAGE method uses in vitro packaging of recombinant DNA into bacteriophage capsids, followed by general transduction to introduce pre-assembled DNA with flanking homology arms into recipient cells. This approach allows efficient and landing pad-free integration of large constructs into the target loci. We demonstrate its usefulness through rapid integration of multi-gene operons. PhAGE resolves the long-standing trade-off between simplicity and insert size in E. coli genome engineering, accelerating strain construction across a wide range of applications, from biosynthetic pathway engineering to genome-scale design.

synthetic biology↗

Biochemical and structural characterisation of MprF homologue,LpiA from Agrobacterium

Multiple peptide resistance factor (MprF) are bi-functional enzymes encoded by several bacterial species and carry out the transfer of an amino acid from a charged tRNA to the lipid head group and further translocate the lipid across the membrane. Biochemical studies have revealed that the soluble synthase domain generates specificity and the structures of MprF have defined the general architecture of these enzymes, and that they can exist in different oligomeric states. Here, we characterise the gene product of lpiA, a MprF homologue from Agrobacterium fabrum (formerly called A. tumefaciens strain C58), a microbe that is commonly used in plant molecular biology. Cryo-EM analysis of AfMprF reveals a dimeric structure both in detergent micelle and in lipid nanodisc, and similar in architecture to the homologous enzyme from related Rhizobium sp. We further analyse some conserved residues in the soluble domain and suggest that the sulphur-aromatic motifs play a key role in substrate binding. Similar architecture of enzymes in closely related bacterial species of Agrobacterium and Rhizobium hints an evolutionary relationship but the importance of these oligomeric states in vivo remains to be analysed.

biochemistry↗

RNAP-seq: in vitro genome-scale transcription reveals preferential RNA polymerase pausing on Clostridioides difficile antisense DNA

Mechanistic dissection of gene transcription and its regulation in diverse organisms remains a central challenge for molecular biology. In vivo analyses using high-throughput DNA sequencing readouts (e.g., RNA-seq, Term-seq, and NET-seq) have revealed that transcriptional pausing by RNA polymerase (RNAP) underpins the regulation of gene transcription. However, these in vivo methods are difficult to apply in non-model organisms and lack the power of bottom-up biochemical analysis that can deconvolute the confounding effects of the cellular environment. Here we report a method for unbiased transcription of entire genomes in vitro called RNAP-seq, which is capable of defining pause, arrest, and termination sites with single-nucleotide resolution and of defining the regulatory contributions of cis-acting RNA and DNA sequences and dissociable transcription factors with complete control over transcription conditions. Using RNAP-seq to compare transcription by recombinant RNAPs from Clostridioides difficile (Cdf) and Escherichia coli (Eco), we discovered that CdfRNAP exhibits pausing signatures distinct from EcoRNAP. CdfRNAP pauses more frequently and more strongly at T-rich sequences, particularly on antisense regions of genes. We also defined the action of CdfNusG at genome scale, revealing its preferential action in riboswitch control regions. These findings demonstrate lineage-specific pausing features and suggest that genome composition and RNAP co-evolve to shape gene expression. RNAP-seq is broadly adaptable to diverse bacterial species and offers a powerful framework for uncovering fundamental principles of transcription that govern gene expression. HighlightsO_LIRNAP-seq enables unbiased transcription of every base-pair in an organisms genome C_LIO_LIRNAP-seq reveals distinct E. coli (Eco) and C. difficile (Cdf) pause sequences C_LIO_LICdfNusG broadly enhances pausing and termination, notably in riboswitch-encoding DNA C_LIO_LICdfRNAP but not EcoRNAP pauses more on the T-rich antisense strand of Cdf genes C_LI

genomics↗

Leveraging a genetically tractable alphaproteobacterium reveals molecular determinants of bacterial growth in fungal-decayed wood

Brown rot wood-degrading fungi release carbon (C) from deadwood but leave behind a large fraction of C sequestered in lignin residues or as fungal metabolites. The strength of sequestration in these C residuals remains unclear, but proteobacteria-dominated bacterial communities have been implicated in metabolizing C from decay residues, possibly erasing the C sequestration potential assumed for brown rot. Here, we paired a model brown rot fungus (Rhodonia placenta) with a model Alphaproteobacterium (Rhodopseudomonas palustris) to track fungal release and bacterial utilization of C derived from decaying wood. We found that fungal decay products generated by R. placenta could be used by R. palustris for growth, and later decay stages contained more usable substrates than early stages. High performance liquid chromatography with mass spectrometry identified a range of aromatic and non-aromatic compounds in the fungal-decayed wood, but after 95 days of bacterial growth, R. palustris preferentially consumed non-aromatic acids over aromatic lignin monomers. Genes involved with aromatic compound degradation were unimportant for bacterial growth, and RNA sequencing revealed that aromatic compound degradation genes were repressed on decayed wood extract. Randomly barcoded transposon sequencing failed to identify a solitary catabolic pathway used by R. palustris, suggestive of substrate co-utilization, and surprisingly, showed that genes involved with copper toxicity were essential. Finally, we found that genes involved with biosynthesis of certain cofactors and amino acids were no longer essential on decayed wood extract, suggesting these nutrients were readily accessible. This study helps lay the foundation to understand potential bacterial-fungal interactions in decayed wood. Graphical abstractTo explore how brown rot fungi support and compete with bacterial partners in the wood decay environment, the model brown rot fungus Rhodonia placenta was used to degrade aspen wafers which were then infused into bacterial growth medium. By leveraging the range of molecular biology tools available for the model Alphaproteobacterium Rhodopseudomonas palustris, we discovered that R. palustris preferentially consumes short organic acids instead of aromatic lignin monomers which it would otherwise consume if provided in isolation. Additionally, R. palustris scavenged certain amino acids (AAs) and enzyme cofactors including methionine, biotin, and PLP from the decayed wood extract, highlighting these as key shared resources for bacterial-fungal partnerships. We found that R. placenta increased the concentration of certain metals (Cu and Al) inducing a metal stress response in R. palustris, indicating that metal toxicity could be an important mode of competition between fungi and bacteria in the wood decay environment. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=93 SRC="FIGDIR/small/723453v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@16f31fcorg.highwire.dtl.DTLVardef@13a9b34org.highwire.dtl.DTLVardef@a37dcforg.highwire.dtl.DTLVardef@198bf1c_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

A Conserved Obg-type GTPase sustains protein synthesis and its physiological roles in eukaryotic cells

Translation is regulated both temporally and spatially to ensure that proteins are synthesized at the correct time and delivered to the proper subcellular location. Temporary slowing or halting of ribosomal movement along an mRNA, a physiological pausing, allows cells to coordinate protein production with internal cues and external signals. However, how cells distinguish such constructive pauses from harmful pathological stalls remains a fundamental unresolved question in molecular biology. Here, we report that a ribosome-binding GTPase (Rbg in yeast, and so-called Developmentally Regulated GTP-binding (Drg) in human) promotes protein biosynthesis in halted ribosomes in an evolutionarily conserved manner. We show that the essential bacterial Obg GTPase rescues cell growth and translation in Saccharomyces cerevisiae and human cells lacking their endogenous Rbg/Drg proteins in a GTPase-dependent manner. Furthermore, Obg enhances puromycin incorporation into stalled ribosomes in a manner requiring GTP hydrolysis. We reason that Rbg/Drg proteins act to prevent premature engagement of ribosome-associated quality-control or stress-response pathways. Under physiological conditions, proteomic analyses of Rbg1-bound ribosomes in yeast reveal that Rbg GTPases associate with ribosomes translating proteins essential for diverse functions, including those of the nucleus, ER, Golgi, mitochondria, and protein transport pathways. Finally, loss of even one of the two eukaryotic Rbg/Drg paralogs impedes cell-cycle progression, disrupts DNA replication, and compromises mitochondrial function. Together, these findings suggest that Rbg/Drg proteins enable cells across different domains of life to protect physiological ribosomal pauses, revealing a previously unrecognized layer of regulation in gene expression. Significance StatementHow cells distinguish productive ribosomal pauses from harmful stalls remains unclear. We identify a ribosome-binding GTPase--Rbg in yeast and Drg in humans--as a conserved regulator that protects physiological pauses and sustains protein synthesis. Remarkably, bacterial Obg functionally substitutes for eukaryotic Rbg/Drg in both yeast and human cells, revealing deep evolutionary conservation of this mechanism. Our data show that Obg promotes continued peptide-bond formation in a GTPase-dependent manner. Positioned near the ribosomal GTPase-associated center, these GTPases are also poised to compete with stringent-response and stress-activation factors that trigger translation shutdown. Together, the findings suggest that translation is controlled not only by GTPases that drive protein synthesis forward but also by Rbg/Drg GTPases that protect the catalytic cycle against premature arrest.

biochemistry↗

HESTIA: Scalable Multimodal Integration of Histology and High-Resolution Spatial Transcriptomics for Robust Spatial Domain Identification

Spatial omics has revolutionized molecular biology by providing invaluable insights into how native tissue microenvironments regulate cellular functions and disease mechanisms. Accurately capturing this structural complexity and decoding the underlying biological processes requires effectively integrating data from multiple modalities. However, transitioning to subcellular resolutions introduces massive data scales and severe transcriptomic sparsity, which challenge current analytical frameworks. To address this, we present HESTIA (Histology-Enhanced Scalable cross-Resolution inTegration for spatial trAnscriptomics), a highly efficient multimodal algorithm designed for identifying spatial domains in large-scale, high-resolution spatial omics data. By circumventing memory-intensive computations, HESTIA efficiently processes massive datasets on which existing algorithms fail due to memory constraints. HESTIA outperforms current multimodal methods in clustering accuracy and spatial continuity, accurately delineating fine structural boundaries. Furthermore, applying HESTIA to large-scale pathological samples successfully dissects clinically relevant intratumoral heterogeneity and maps distinct immune microenvironments in lung and colorectal cancers.

bioinformatics↗

Rapid and flexible assessment of gene functions in plant cells with particle bombardment and linear DNA

Biolistic transformation is a versatile tool in plant science, yet high equipment costs and tissue damage from high-pressure gas remain significant barriers. Building on our previously developed "TSGMAC", a low-cost, helium-free biolistic system, we report three major advancements to enhance its throughput, delivery quality, and quantitative capability. First, a "guide barrel" assembled from commercial DIY fittings was developed; it effectively eliminates physical tissue damage and ensures uniform particle distribution, even in soft tissues like bok choy (Brassica rapa subsp. chinensis). Second, a rapid gene expression platform using PCR products was characterized. Results demonstrate that linear DNA constructs are efficiently circularized via non-homologous end joining (NHEJ) in plant cells, and protein expression is robust regardless of the relative positions of the promoter, coding sequence, and terminator. This system bypasses time-consuming cloning. Third, a cost-effective, highly sensitive dual-luciferase assay system utilizing teal Luc (teLuc) and inexpensive firefly luciferase (FLuc) inhibitors was established. This integrated workflow enables rapid, quantitative molecular biology using supermarket-obtained materials and standard PCR reagents. Our findings provide a practical foundation for plant scientists, synergistically accelerating gene functional analysis and genetic tool development.

plant biology↗

ProtmRNA: Cross-Modal Knowledge Transfer from Proteins to Messenger RNA

MotivationAccording to the central dogma of molecular biology, messenger RNA (mRNA) sequences are directly translated into amino acid sequences, positioning mRNA as the fundamental intermediary between genetic information and functional proteins. This natural correspondence suggests that mRNA sequence analysis could greatly benefit from the rich evolutionary and functional representations learned by large-scale protein language models. ResultsProtmRNA repurposes the pre-trained ESM-2 protein language model for mRNA sequence processing via cross-modal transfer learning. Evaluated on mRNA- and protein-related datasets, along with eight additional benchmarks compiled in this study, ProtmRNA achieves performance comparable or superior to state-of-the-art mRNA language models while using less than half the pre-training computational resources. This work establishes the potential of cross-modal transfer learning between biological sequences by demonstrating that protein-derived knowledge can be efficiently transferred to mRNA, offering a resource-efficient paradigm for advancing mRNA sequence understanding. Availability and ImplementationThe pre-trained ProtmRNA model and the eight CDS-region regression benchmarks curated in this study are publicly available at https://github.com/pesenteur/ProtmRNA.

bioinformatics↗

PAD2 knockout reduces myelin protein aggregates, modulates neuroinflammation and protects motor neurons, axons and neuromuscular junction in a SOD1-ALS mouse model

BackgroundDysregulated peptidyl deiminase 2 (PAD2) and aberrant protein citrullination (PC), a posttranslational modification (PTM), are involved in various inflammatory and neurodegenerative diseases. We previously showed in transgenic mice and postmortem human tissues that PC and PAD2 are altered in amyotrophic lateral sclerosis (ALS), a neurodegenerative disease characterized by motor neurons loss, paralysis, and death. Herein, we investigated the role of PAD2 in ALS by PAD2 knockout in a SOD1-ALS mouse model. MethodsTo investigate the role of PAD2-induced citrullination in ALS pathogenesis, we generated PAD2 knockout (PAD2KO) in SOD1G93A ALS mouse model and investigated the consequent modulation on the neuropathology and clinical symptoms, using molecular biology techniques such as qPCR, Western blotting, confocal microscopy, and electron microscopy. Additionally, we identified C3 as being citrullinated in human ALS using ionFinder. ResultsOur results show that PAD2KO blocked the increased PC and reduced myelin basic protein (MBP) aggregates in the ALS model. PAD2KO also improved motor neuron survival and the integrity of myelin, axons, and neuromuscular junctions, and reduced microgliosis in the white matter and C3 protein levels in astrocytes. Clinically, data from monitoring the body weight changes suggests that PAD2KO modulates the course of the disease in the ALS mouse model, accelerating the onset while slowing the progression after the onset, and modestly extending the survival of male mice. ConclusionThese results show that PAD2 is responsible for the increased PC in ALS and PC contributes to neuroinflammation and degeneration of motor neurons and myelinated axons. The modest modulation of the disease phenotype suggests that the role of PC in ALS is complex, involving altered PC in numerous proteins and in multiple cell types. Future studies are needed to investigate how PC modulates individual protein functions in various cell types to understand the contribution of PC to ALS pathogenesis.

neuroscience↗

Hierarchical refinements of cis-regulatory inputs improve scalable gene expression prediction

Deciphering the relationships between cis-regulatory elements (CREs) and target gene expression has long been a challenging problem in molecular biology. However, predicting gene expression from hundreds of candidate cis-regulatory elements (cCREs) requires models that scale to long, noisy inputs while retaining interpretable regulatory structure. Existing Transformer-based approaches typically attend over all nucleotides and all surrounding cCREs, diluting causal signals when hundreds of elements compete for limited model capacity. Here we introduce a two-stage selective framework (TSSF) that performs hierarchical refinements: nucleotide-level masking within each cCRE, followed by cCRE-level selection around each gene, implemented with information-bottleneck priors and a fully Transformer-based architecture. Across 70 human cell types and tissues, TSSF and lightweight variants improve expression prediction and enhancer-gene prioritization relative to strong baselines, including on cross-cell-line and cell-type-specific benchmarks. Prediction-stratified analysis motivates a distance-decay prior that aligns attention with long-range regulatory geometry, and chromatin-contact augmentation improves recovery of distal links. Motif analyses of high-confidence predictions recover proximal and distal regulatory programs, supporting mechanistic interpretability. TSSF offers a general strategy for scalable, interpretable modeling of high-dimensional regulatory inputs in genomics.

bioinformatics↗

Functional divergence of the NSs protein defines interferon antagonism and viral fitness across Bhanja virus lineages.

Bhanja virus (BHAV) is a tick-borne bandavirus (Family Phenuiviridae) with a broad geographic distribution and documented neuroinvasive capacity, yet its molecular biology remains poorly understood. Within the genus Bandavirus, the non-structural protein NSs functions as the primary antagonist of innate immune responses, although mechanistic details for BHAV remain unknown. We established a reverse genetics platform for BHAV by combining virion RNA sequencing with terminal untranslated region mapping, enabling generation of recombinant viruses and systematic investigation of viral determinants. Using this system, we characterized recombinant BHAV replication in mammalian and arthropod cell lines and demonstrated that interferon competence is a critical determinant of viral replication in mammalian cells. Notably, we observed substantial amino acid divergence within the NSs protein across geographically distinct BHAV isolates, despite higher conservation of other viral proteins. To investigate the functional significance of this variation, we generated recombinant viruses expressing heterologous NSs proteins from African and European isolates. Viruses expressing NSs from ibAr2709 or R1819 isolates exhibited enhanced capacity to suppress interferon-beta induction compared to the prototype IG690 strain, correlating with increased viral protein accumulation in interferon-competent cells. Mechanistic studies revealed that BHAV NSs proteins inhibit interferon induction upstream of IRF3, with ibAr2709 and R1819 NSs showing selective inhibition of TBK1 phosphorylation. However, unlike highly pathogenic bandaviruses such as severe fever with thrombocytopenia syndrome virus (SFTSV), BHAV NSs proteins exhibit comparatively weak antagonism of downstream interferon signalling. In vivo studies using interferon alpha/beta receptor-deficient mice demonstrated that NSs sequence variation influences viral replication in splenic tissue without substantially altering disease phenotype. Together, these findings establish BHAV reverse genetics tools for future investigation and reveal how naturally-occurring NSs divergence modulates innate immune antagonism and viral fitness while maintaining an overall attenuated disease phenotype. Author SummaryBhanja virus is a tick-borne virus distributed across Asia, Africa, and Europe that causes neurological disease, yet little is known about how it replicates or evades immunity. We developed the laboratory tools to create recombinant Bhanja viruses and investigate viral functions. We discovered that the virus replicates efficiently in cells lacking interferon responses but is severely restricted in normal immune-competent cells, revealing interferon as a major barrier to viral growth. We observed that Bhanja virus isolates from distinct geographic regions have different versions of a viral protein called NSs that suppresses interferon responses. Isolates from Africa and Europe were better at blocking interferon production than the original Asian strain, correlating with increased viral growth in immune-competent cells. However, unlike related viruses that cause more serious disease such as SFTSV, BHAV NSs proteins only partially antagonise interferon. While this weak antagonism likely contributes to the attenuated phenotype observed in our experimental systems, the natural pathogenesis of Bhanja virus in human hosts and tick vectors remains to be determined. This study provides tools for examining Bhanja virus biology and demonstrates that small viral differences in viral sequence can meaningfully influence evasion of innate immunity and viral fitness without triggering severe disease.

microbiology↗