Biology subjects

Cui, X.

Publications and source records attributed to Cui, X..

At least 55 records · Page 3Linked to original sources

bioRxiv2025

Epigenetic Programming of Estrogen Receptor in Adipose Tissue by High Fat Diet Regulates Obesity-Induced Inflammation

Adipose inflammation plays a key role in obesity-induced metabolic abnormalities. Epigenetic regulation, including DNA methylation, is a molecular link between environmental factors and complex diseases. Here we found that high fat diet (HFD) feeding induced a dynamic change of DNA methylome in mouse white adipose tissue (WAT) analyzed by reduced representative bisulfite sequencing. Interestingly, DNA methylation at the promoter of estrogen receptor (Esr1) was significantly increased by HFD, concomitant with a down-regulation of Esr1 expression. HFD feeding in mice increased the expression of DNA methyltransferase 1 (Dnmt1) and Dnmt3a, and binding of DNMT1 and DNMT3a to Esr1 promoter in WAT. Mice with adipocyte-specific Dnmt1 deficiency displayed increased Esr1 expression, decreased adipose inflammation and improved insulin sensitivity upon HFD challenge; while mice with adipocyte-specific Dnmt3a deficiency showed a mild metabolic phenotype. Using a modified CRISPR/RNA-guided system to specifically target DNA methylation at the Esr1 promoter in WAT, we found that reducing DNA methylation at Esr1 promoter increased Esr1 expression, decreased adipose inflammation and improved insulin sensitivity in HFD-challenged mice. Our study demonstrates that DNA methylation at Esr1 promoter plays an important role in regulating adipose inflammation, which may contribute to obesity-induced insulin resistance.

physiology↗

bioRxiv2025

Capture-C MPRA: A high-throughput method to simultaneously characterize promoter interactions and regulatory activity

Cis regulatory elements (CREs) interact with their target promoters over long genomic distances and can be identified using chromatin conformation capture (3C) assays. Their regulatory activity can be functionally characterized in a high-throughput manner using massively parallel reporter assays (MPRAs) that generally test an enhancer alongside a minimal promoter. Here, we developed a novel technology called Capture-C MPRA (ccMPRA) that combines both technologies and can simultaneously obtain chromatin interactions and measure CRE activity alongside their target promoters. We utilized ccMPRA to analyze the regulatory activity of 650 promoters interacting with 42,719 sequences. As C-based techniques also capture isolated promoters, we were able to obtain promoter baseline activity, enabling the identification of both enhancers and silencers. Analysis of CREs interacting with more than one promoter showed significant activity differences depending on the promoter. In summary, ccMPRA can simultaneously characterize chromatin interactions and regulatory activity, allowing to further dissect regulatory grammar.

genomics↗

bioRxiv2025

F-53B damages cell viability leading to impaired root development in Arabidopsis

The emerging contaminant chlorinated polyfluoroalkyl ether sulfonate (Cl-PFAES/F-53B) has been detected in many plant species, however, the impact of F-53B on the development in plants and the underpinning mechanisms remain largely unelucidated. In this study, we demonstrate by molecular biology, cytogenetics, and fluorescence microscopy mythologies that F-53B impairs cell viability leading to disrupted root development in Arabidopsis (Arabidopsis thaliana). We show that F-53B suppresses root length and the inhibitory effect is pronunanced at increasing concentrations. F-53B disrupts cell wall and microtubule-mediated cell plate formation and configuration in meristem cells, revealing its toxicity to cell division and cytoskeleton organization. F-53B induces cell death predominantly at the meristematic zone, however, gene exression and genetic studies indicate that F-53B does not trigger DNA double-strand breaks, implying a divergent effect on DNA stability across species. Moreover, we show that F-53B damages nuclei stability and viability, and induces Autophagy-Related 8 protein foci formation implying that it triggers autophagy-mediated cell responses. Taken together, this study provides cellular and molecular insights into the toxicity of F-53B to plant cells, which highlights its damage to agriculture and ecology security that deserve imperative environmental management actions. Environmental ImplicationF-53B has been detected in many plant species, which raises increasing concerns on its toxicity to plants and thus agriculture and ecology safety. However, the toxicity of F-53B to development in plants and the underpinning mechanisms remain largely unelucidated. Here, we demonstrate that F-53B damages nuclei stability and viability leading to cell death and impaired root development in the model plant species Arabidopsis thaliana. Our study provides cytogenetic and molecular insights into the F-53B toxicity to plant cells, which highlights imperative environmental management actions and can be referenced for developing F-53B control and management policies. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=143 SRC="FIGDIR/small/653422v1_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@159b211org.highwire.dtl.DTLVardef@1b99a95org.highwire.dtl.DTLVardef@53b964org.highwire.dtl.DTLVardef@b089be_HPS_FORMAT_FIGEXP M_FIG C_FIG One-sentence summaryF-53B triggers DNA double-strand break-free cell unviability leading to impaired meristematic cell division and root development in plants. HIGHLIGHTSO_LIF-53B impairs root development in Arabidopsis. C_LIO_LIF-53B prohibits mitotic cell division at root tips. C_LIO_LIF-53B damages cell viability predominantly at the meristematic zone in seedlings. C_LIO_LIF-53B does not induce DNA double-strand breaks in Arabidopsis seedlings. C_LIO_LIF-53B damages nuclei viability and stability in seedlings. C_LI

developmental biology↗

bioRxiv2025

Derepression of transposable elements in mouse prefrontal cortex disrupts social behavior

Here, we present a synthetic biology approach to assess the social behavioral consequences of altered function of the Kruppel-associated box zinc finger protein (KZFP) interacting protein TRIM28 within the prefrontal cortex (PFC) of male and female mice. We reprogrammed natural TRIM28WT by replacing the transcriptionally repressive domain with an enhanced transcriptional activation domain VP64-p65-Rta (TRIM28VPR), or by excising the transcriptional regulatory domain (TRIM28NFD). In vitro validation confirmed that TRIM28WT represses, and TRIM28VPR activates, the expression of a KZFP-regulated luciferase reporter gene. Upon intra-PFC viral-mediated delivery of TRIM28 variants, we observed that inversion of TRIM28 transcriptional control via HSV-TRIM28VPR reduced the salience of novel social interaction for male and female mice while not affecting non-social behaviors. RNA-sequencing revealed HSV-TRIM28VPR promoted transcriptional escape of all classes of TEs, particularly those located within intronic and distal enhancer regions of downregulated immune genes. HSV-TRIM28VPR-driven social deficits were reversible by intra-PFC repletion of interferon cytokines. These novel data point to PFC KZFP-TRIM28 interactions as necessary to stabilize TEs to enable cis-regulation of key immune gene expression and enhance organismal capacity for complex, pro-social behaviors.

neuroscience↗

bioRxiv2025

AI-Driven Efficient De Novo design of GLP-1RAs with Extended Half-Life and Enhanced Efficacy

Peptide drug has revolutionized modern therapeutics, offering novel treatment avenues for various diseases. However, low efficacy, time consumption, and high cost hinder peptide drug design and discovery. We present an efficientin approach that integrates deep learning-based protein design with efficient functional screening, enabling the rapid design of biotechnologically important peptides with improved the stability and efficacy. We designed 10,000 de novo GLP-1 receptor agonists (GLP-1RAs), of which 60 met the stability, efficacy, and diversity criteria in the vitral functional screening. In vitro validation revealed a 62% success rate, while in vivo experiment demonstrated that two designed GLP-1RAs exhibited significantly extended half-lives, approximately three times longer than Semaglutide. In diabetic and obesity mouse models, the most competitive candidate showed superior therapeutic efficacy over Semaglutide. Our AI driven peptide design pipline integrats protein design, functional screening, and experiment validation, reducing the number of iterations required to find novel peptide candidates. The entire process, from design to screening, can be completed in a single cycle within two weeks.

bioengineering↗

bioRxiv2025

CompBioAgent: an LLM-powered agent for single-cell RNA-seq data exploration

AO_SCPLOWBSTRACTC_SCPLOWAdvancements in high-throughput biological technologies, particularly single-cell RNA sequencing (scRNA-seq), have generated vast amounts of complex data that offer valuable insights into gene expression, cellular behavior, and disease mechanisms. However, the analysis of such data often requires specialized computational skills and expertise, which can pose a barrier to many researchers. To address this challenge, we developed CompBioAgent, a user-friendly web application designed to democratize access to bioinformatics resources, powered by Large Language Models (LLMs). By integrating with the CellDepot, CompBioAgent allows users to easily query and explore gene expression data related to various diseases, cell types, and experimental conditions. Moreover, the tool employs Cellxgene Visualization In Plugin (Cellxgene VIP) platform to generate a range of intuitive visualizations, including violin plots, UMAP embeddings, heatmaps, etc. With its natural language interface, CompBioAgent automatically converts scientific queries into structured data requests and returns the plot of interest, enabling seamless exploration of biological data without the need for programming expertise. Such integration enhances the ability of researchers to visualize complex biological insights and identify key patterns, making high-level data analysis more accessible and efficient. A demo website and a list of examples are available at https://celldepot.bxgenomics.com/compbioagent, and the source code is released at https://github.com/interactivereport/compbioagent.

bioinformatics↗

bioRxiv2025

SEL1L-HRD1 ER-Associated Degradation Facilitates Prohormone Convertase 2 Maturation and Glucagon Production in Islet α Cells

Proteolytic cleavage of proglucagon by prohormone convertase 2 (PC2) is required for islet cells to generate glucagon. However, the regulatory mechanisms underlying this process remain largely unclear. Here, we report that SEL1L-HRD1 endoplasmic reticulum (ER)-associated degradation (ERAD), a highly conserved protein quality control system responsible for clearing misfolded proteins from the ER, plays a key role in glucagon production by regulating turnover of the nascent proform of the PC2 enzyme (proPC2). Using a mouse model with SEL1L deletion in proglucagon-expressing cells, we observed a progressive decline in stimulated glucagon secretion and a reduction in pancreatic glucagon content. Mechanistically, we found that endogenous proPC2 is a substrate of SEL1L-HRD1 ERAD, and that degradation of misfolded proPC2 ensures the maturation of activation-competent proPC2 protein. These findings identify ERAD as a novel regulator of PC2 biology and an essential mechanism for maintaining cell function.

cell biology↗

bioRxiv2025

KcatNet: advancing genome-wide enzyme turnover number prediction through structural enzymatic characterization

Enzyme turnover numbers (Kcat) are fundamental kinetic constants that quantify enzymatic efficiency. Systematic studies of Kcat are essential for characterizing the mechanisms underlying proteomic composition and cellular metabolism. However, experimental measurements of Kcat remain limited and prone to noise. To address this, we present KcatNet, a geometric deep learning model designed for high-throughput prediction of Kcat in metabolic enzymes across all organisms, leveraging paired enzyme sequence and substrate representations. KcatNet consistently outperforms existing predictors, particularly for enzymes with high catalytic efficiency, and demonstrates strong generalization to enzymes that are dissimilar to those in the training set. Furthermore, KcatNet uncovers structural mechanisms and interaction patterns within enzyme-substrate complexes, providing insights into architectural principles that are inaccessible with existing methods by harnessing the representational power of large-scale protein language models. We applied KcatNet to genome-scale Kcat prediction across diverse yeast species, improving proteome allocation predictions by integrating its outputs into metabolic models. Experimental validation further confirmed the models ability to identify enzyme mutants with enhanced activity. By bridging the gap between sequence, structure, and function, KcatNet establishes a robust foundation for advancing understanding of molecular-level mechanisms and accelerating enzyme engineering efforts.

bioinformatics↗

bioRxiv2025

ProDualNet: Dual-Target Protein Sequence Design Method Based on Protein Language Model and Structure Model

Proteins typically interact with multiple partners to regulate biological processes, and peptide drugs targeting multiple receptors have shown strong therapeutic potential, emphasizing the need for multi-target strategies in protein design. However, most current protein sequence design methods focus on interactions with a single receptor, often neglecting the complexity of designing proteins that can bind to two distinct receptors. We introduced ProDualNet, a novel approach for designing dual-target protein sequences by integrating sequence-structure information from two distinct receptors. ProDualNet used a heterogeneous graph network for pretraining and combines noise-augmented single-target data with real dual-target data for fine-tuning. This approach addressed the challenge of limited dual-target protein experimental structures. The efficacy of ProDualNet has been validated across multiple test sets, demonstrating better recovery and success rates compared to other multi-state design methods. In silico evaluation of cases like dual-target allosteric binding and non-overlapping interface binding highlights its potential for designing dual-target binding proteins. Furthermore, we validated ProDualNets ability to model the relationships between sequences, structures, and functions by zero-shot prediction tasks, including dual-target protein functional effects and mutant functional effects.

bioinformatics↗

bioRxiv2025

Lower spatial turnover of rare fungal taxa dominantly shaped by stochastic processes in grassland soils

The spatial pattern and community assembly of soil microbial taxa have notable meanings for biodiversity shaping and maintaining mechanisms. Rare fungal taxa may exhibit distinct patterns and assembly mechanisms compared to abundant taxa, but such information is limited, especially at large scales. Here, we investigated distance-decay patterns and underlying assembly mechanisms for abundant and rare fungal taxa in 129 soil samples collected across 4,000 km in Chinese Northern grasslands, based on high-throughput sequencing data. A total of 208 abundant OTUs (relative abundance > 0.1%, 2.73% of entire OTUs) and 5,779 rare OTUs (relative abundance < 0.01%, 75.85% of entire OTUs) were identified. Both abundant and rare fungal taxa showed significant distance-decay relationships (P < 0.001), but the turnover rate for rare taxa (0.0024 per 100 km) was nearly half that of abundant taxa (0.0054 per 100 km) based on the binary Bray-Curtis distance. The lower turnover of rare fungal taxa was likely due to their community assembly mechanism dominated by stochastic processes, which were less influenced by environmental gradients. In contrast, abundant taxa assembly was dominated by deterministic factors like soil variables and plant traits, which varied significantly along the geographic distance. Consistently, rare fungal taxa were also less sensitive to environmental changes, with a lower turnover rate by environmental distance (0.0027 vs. 0.0099) than abundant taxa. In summary, our findings revealed that rare fungal taxa, shaped mainly by stochastic processes, had lower spatial turnover compared to abundant taxa, dominated by deterministic processes, enhancing our understanding of rare microbial biogeography.

ecology↗

bioRxiv2024

Dissociable neurofunctional and molecular characterizations of reward and punishment sensitivity

While the hyper-and hypo-reward or punishment sensitivities (RS, PS) have received considerable attention as prominent transdiagnostic features of psychopathology, the lack of an overarching neurobiological characterization currently limits their early identifications and neuromodulations. Here we combined microarray data from the Allen Human Brain Atlas with a multimodal fMRI approach to uncover the neurobiological signatures of RS and PS in a discovery-replication design (N=655 participants). Both RS and PS were mapped separately in the brain, with the intrinsic functional connectome in the fronto-striatal network encoding reward responsiveness, while the fronto-insular system was particularly engaged in punishment sensitivity. This dissociable functional connectome patterns related to RS and PS were also specific in differentiating decisions driven by social or monetary reward and punishment motivations. Further imaging transcriptomic analyses revealed that functional connectome variations for RS and PS were associated with topography of specific gene sets enriched in ontological pathways, including synaptic transmission, dopaminergic metabolism, immune response and stress adaptation. On the neurotransmitter level, the serotonin neuromodulator was identified as a pivotal hub regulating the intrinsic functional connectome patterns of RS and PS, with this process critically dependent on its interactions with dopaminergic, opioid and GABAergic systems. Overall, these findings indicate dissociable neural connectome mapping of RS and PS and highlight their linkage with transcriptomic profiles, which may offer valuable insights into the treatment evaluation for symptomatology relevant to reward/punishment processing deficits.

neuroscience↗

bioRxiv2024

Identification of SMARCA1 as a key regulator for Colorectal Cancer

Emerging evidence indicates that aberrations in the writing, reading, or erasure of chromatin modification codes are pivotal events in various human cancers. In this study, we conducted a systematic investigation of histone modification recognition proteins in a pair of colorectal cancer cell lines, SW480 and SW620. Using chromatin fractionation combined with data-independent acquisition mass spectrometry (DIA-MS), we developed a robust method to identify changes in histone modification recognition proteins during cancer progression. Our analysis revealed 22 proteins that were significantly upregulated and 22 proteins that were significantly downregulated in SW620 cells compared to SW480 cells. Notably, SMARCA1, a member of the ISWI family belonging to ATP-dependent chromatin remodeling complexes, was downregulated in SW620 cells compared to SW480 cells. Its high expression was strongly correlated with poor patient prognosis, aligning with the proposed role of SMARCA1 in promoting colorectal cancer (CRC) metastasis. Furthermore, reduced SMARCA1 expression altered the levels of metastasis-related matrix metalloproteinases (MMPs) in these cells. In conclusion, by systematically profiling histone modification recognition proteins in a matched pair of primary and metastatic CRC cell lines, we identified SMARCA1 as a potential driver of CRC metastasis and a promising therapeutic target for CRC patients.

cancer biology↗

bioRxiv2024

EpiAgent: Foundation model for single-cell epigenomic data

Large-scale foundation models have recently opened new avenues for artificial general intelligence. Such a research paradigm has recently shown considerable promise in the analysis of single-cell sequencing data, while to date, efforts have centered on transcriptome. In contrast to gene expression, chromatin accessibility provides more decisive insights into cell states, shaping the chromatin regulatory landscapes that control transcription in distinct cell types. Yet, challenges also persist due to the abundance of features, high data sparsity, and the quasi-binary nature of these data. Here, we introduce EpiAgent, the first foundation model for single-cell epigenomic data, pretrained on a large-scale Human-scATAC-Corpus comprising approximately 5 million cells and 35 billion tokens. EpiAgent encodes chromatin accessibility patterns of cells as concise "cell sentences," and employs bidirectional attention to capture cellular heterogeneity behind regulatory networks. With comprehensive benchmarks, we demonstrate that EpiAgent excels in typical downstream tasks, including unsupervised feature extraction, supervised cell annotation, and data imputation. By incorporating external embeddings, EpiAgent facilitates the prediction of cellular responses to both out-of-sample stimulated and unseen genetic perturbations, as well as reference data integration and query data mapping. By simulating the knockout of key cis-regulatory elements, EpiAgent enables in-silico treatment for cancer analysis. We further extended zero-shot capabilities of EpiAgent, allowing direct cell type annotation on newly sequenced datasets without additional training.

bioinformatics↗

bioRxiv2024

Oral supplementation with Nicotinamide Riboside treatment protects RGCs in DBA/2J mouse model

PurposeThe aim of this study was to test whether oral administration of nicotinamide riboside (NR), the nicotinamide adenine dinucleotide (NAD+) precursors, protect retina ganglion cells (RGCs) from neurodegeneration in DBA/2J (D2) mice, which is a widely used mouse model of age-related inherited glaucoma. MethodOral NR or NAM administration (NR low dose: 1150mg/kg; NR high dose: 4200mg/kg; NAM low dose group: 500mg/kg; NAM high dose: 2000mg/kg of body weight per day) essentially started when D2 mice were 4 or 9 months old and continued up to 12 months old. Control cohort identically received food/water without NAM or NR. Intraocular pressure (IOP) was measured every month until experiment completion. Pattern electroretinography (PERG) was recorded. Retinas were harvested for whole mount immunofluorescence staining with RGCs marker Brn3a and imaged by fluorescent confocal microscopy. Optic nerves were harvested for axon staining and quantification. Retinal NAD+ levels were enzymatically assayed. ResultsNR oral supplementary treatment started at 4 months old robustly increased retinal NAD+ levels in D2 mice (NRHigh vs. vehicle: 273.7{+/-}23.59% vs. 108.70{+/-}12.10%, p<0.001). In aged vehicle group (12 months old), there was significantly diminution of the P1 and N2 components of PERG response compare with naive group (naive vs. vehicle: P1: 7.82{+/-} 0.70uV vs 1.63{+/-} 0.17uV, p<0.0001; N2: -13.29{+/-} 0.83uV vs. -3.22{+/-} 0.27uV, p<0.0001; Kruskal-Wallis test with Dunn s multiple comparison test). NR treatment preserved aged D2 visual function when mice were 9 and 12 months old. In addition, long-term NR high dose treatment significantly protected against total RGCs loss and optic nerve atrophy (RGC: NRHigh vs. vehicle: 1412{+/-}62.00vs 475.2{+/-}94.68 cells/field, p<0.00001; axon numbers: NRHigh vs. vehicle: 23990{+/-}1159 vs 8573{+/-}1160, n=41-53, p<0.0001). Furthermore, long-term NR supplementation prevent iris depigmentation and delayed IOP elevation. ConclusionNR oral supplementary treatment significantly preserved RGC and axon numbers, potentially preserves retinal function via elevated retinal NAD+ level in aged D2 mice. Interestingly, NR treatment also prevented iris atrophy, delayed IOP elevation associated with this glaucoma model. NR oral supplementation thus treated several aspects of murine pigment dispersion glaucoma. Given parallels between this model and glaucoma in human, out data indicate that NR is worth exploring as a therapeutic candidate in treatment of glaucoma.

neuroscience↗

bioRxiv2024

Efficient creation and characterization of multi-kilobase knockins by CRISPR/Cas9 and multiple rAAVs

Multi-kilobase knock-ins (KIs) are a necessary, yet challenging type of genome editing to create and characterize in cell lines and animals. The combination of rAAV donor transduction and electroporation of single-cell mouse embryos with Cas9/gRNA ribonucleoprotein complex (RNP) enables highly efficient KI, but the insert size is limited by the viral packaging capacity. Here, we report the creation of up to 6.6 kb precise KI achieved in one step by using three rAAVs designed to insert one after the other. To fully characterize the edited genome with large KIs, we developed LOCK-seq (LOng-read sequencing of Captured Kilo-base targets), where relevant genomic regions are enriched via hybridization, achieving over 100-fold greater coverage compared to other long-read methods with enrichment. LOCK-seq simultaneously detects the presence of the KI allele, genotypes non-KI alleles and more importantly, uniquely identifies donor concatenation in the KI allele, and localizes random integration of the full or partial donor. Additionally, the multi-rAAV donor approach is successfully applied to cell lines, including lines intolerant of plasmid DNA, whereas LOCK-seq reliably and efficiently screens for KI clones. Together, the two approaches significantly improve the creation and precision of knock-in models. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=81 SRC="FIGDIR/small/625457v3_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@1619b77org.highwire.dtl.DTLVardef@125b0b2org.highwire.dtl.DTLVardef@173b12dorg.highwire.dtl.DTLVardef@7519b1_HPS_FORMAT_FIGEXP M_FIG C_FIG

genetics↗

bioRxiv2024

Identification and genomic characterization of a novel bisegmented coronavirus in the lesser panda

Coronaviruses (CoVs) are enveloped positive-sense single-stranded RNA viruses and are renowned for their capacity to infect a diverse range of animals, including humans. In this study, we report the identification and characterization of a novel bisegmented coronavirus, designated LpCoV, from a dead lesser panda, which exhibited severe clinical manifestations and lesions in multiple organs. The LpCoV represents the first documented coronavirus with a unique bisegmented genome while maintaining the typical coronavirus morphology. One genomic segment encodes the ORF1ab polyprotein, while the other segment encodes the spike and nucleocapsid proteins, notably lacking the envelope (E) and membrane (M) genes. The pairwise patristic distances of the five concatenated domains in the replicase region (3CLpro, NiRAN, RdRP, ZBD, and HEL1) between LpCoV and -{delta} coronaviruses range from 1.19 to 1.70. Based on the classification criteria established by the International Committee on Taxonomy of Viruses (ICTV), LpCoV is proposed to constitute a new genus within the Coronaviridae family. An epidemiological investigation identified five LpCoV-like viruses in lesser pandas from two different provinces (Sichuan and Jiangsu) indicating the long-term circulation and expansion of bisegmented coronaviruses in wildlife. These findings highlight the imperative for comprehensive viral surveillance in wildlife, which is essential for understanding and mitigating the risk of animal diseases and zoonotic spillover.

microbiology↗

bioRxiv2024

Lrp1 facilitates infection of neurons by Jamestown Canyon virus

Jamestown Canyon virus (JCV) is a bunyavirus and arbovirus responsible for neuroinvasive disease in the United States. Little is known about JCV pathogenesis, and no host factors required for cellular infection have been identified. Recently, we identified low-density lipoprotein receptor related protein 1 (Lrp1) as a host entry factor for two other bunyaviruses Rift Valley fever virus (RVFV) and Oropouche virus (OROV). Here, we assessed the role of Lrp1 in mediating JCV cellular infection of neurons. Both neuronal and non-neuronal immortalized cell lines deficient for Lrp1 displayed reduction in infection with JCV, and early stages of infection such as binding and internalization were impacted by lack of Lrp1. In primary rat neurons, Lrp1 was highly expressed, and the neurons were highly permissive for JCV infection. Treatment of primary neurons with recombinant receptor-associated protein (RAP), a high affinity ligand for Lrp1, resulted in reduced infectivity with JCV. In addition, pretreatment of cells with RVFV Gn inhibited JCV infection, suggesting that the two viruses may share overlapping binding sites. These results provide compelling evidence that Lrp1 is an important cellular factor for efficient infection by JCV, and thus multiple bunyaviruses with varying clinical manifestations and tissue tropism are facilitated by the host cell Lrp1. Reliance of multiple bunyaviruses on Lrp1 makes it a promising target for pan-bunyaviral antivirals and therapeutics.

microbiology↗

bioRxiv2024

Switch of TIR signaling by a Ca2+ sensor activates ADR1 recognition of pRib-AMP-EDS1-PAD4 for stomatal immunity

Plants swiftly close stomata upon detecting pathogen entry, a crucial defense termed stomatal immunity. The process is initiated by cell-surface pattern recognition receptors (PRRs) that perceive pathogen-associated molecular patterns (PAMPs) and evoke a series of early cellular responses including calcium ions (Ca2+) influx, and is conducted by the intracellular nucleotide-binding leucine-rich-repeat receptors (NLRs) ADR1s within an EDS1-PAD4-ADR1 module. However, the underlying mechanisms linking PRR signaling to the NLRs ADR1s remain unclear. Here, we show that the Nicotiana benthamiana Toll/interleukin-1 receptor (TIR)-only protein Stomatal TIR1 (STIR1) produces the immune molecule pRib-AMP, induces formation of EDS1-PAD4-ADR1 complexes, and mediates stomatal immunity. The Inhibitor of Stomatal Immunity C2-domain protein 1 (ISIC1) interacts with and constrains STIR1 function at basal condition, whereas upon pathogen infection, ISIC1 senses Ca2+ signals and de-represses STIR1 signaling. Cryo-electron microscopy structure of pathogen infection-elicited Arabidopsis AtEDS1-AtPAD4-AtADR1-L2 complex reveals the pRib-AMP binding to AtEDS1-AtPAD4 receptor and the AtADR1-L2 recognition of pRib-AMP-AtPAD4-AtEDS1 for stomatal immunity. Collectively, this study uncovers a repression/de-repression mechanism linking PRR signaling to NLRs by a Ca2+ sensor/TIR-only node, and elucidates an NLR recognition mechanism of the pRib-AMP-EDS1-PAD4 complex in governing innate immunity. SynopsisAt basal condition, the Ca2+ sensor ISIC1 interacts with and inhibits the TIR-only protein STIR1; upon pathogen infection, ISIC1 perceives Ca2+ signal and releases STIR1 to produce pRib-AMP; the EDS1-PAD4 receptor binds pRib-AMP and is recognized by the NLR ADR1-L2, thereby activating stomatal immunity.

plant biology↗