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Li, S.

Publications and source records attributed to Li, S..

At least 505 records · Page 28Linked to original sources

Cell-based high-content approach for SARS-CoV-2 neutralization identifies unique monoclonal antibodies and PI3K pathway inhibitors.

The sudden rise of the SARS-CoV-2 virus and the delay in the development of effective therapeutics to mitigate it made evident a need for ways to screen for compounds that can block infection and prevent further pathogenesis and spread. Yet, identifying effective drugs efficacious against viral infection and replication with minimal toxicity for the patient can be difficult. Monoclonal antibodies were shown to be effective, yet as the SARS-CoV-2 mutated, these antibodies became ineffective. Small molecule antivirals were identified using pseudovirus constructs to recapitulate infection in non-human cells, such as Vero E6 cells. However, the impact was limited due to poor translation of these compounds in the clinical setting. This is partly due to the lack of similarity of screening platforms to the in vivo physiology of the patient and partly because drugs effective in vitro showed dose-limiting toxicities. In this study, we performed two high-throughput screens in human lung adenocarcinoma cells with authentic SARS-CoV-2 virus to identify both monoclonal antibodies that neutralize the virus and clinically useful kinase inhibitors to block the virus and prioritize minimal host toxicity. Using high-content imaging combined with single-cell and multidimensional analysis, we identified antibodies and kinase inhibitors that reduce virus infection without affecting the host. Our screening technique uncovered novel antibodies and overlooked kinase inhibitors (i.e. PIK3i, mTORi, multiple RTKi) that could be effective against SARS-CoV-2 virus. Further characterization of these molecules will streamline the repurposing of compounds for the treatment of future pandemics and uncover novel mechanisms viruses use to hijack and infect host cells.

pharmacology and toxicology↗

Conserved chromatin regulators control the transcriptional immune response to intracellular pathogens in Caenorhabditis elegans

Robust transcriptional responses are critical for defense against infection. However, unrestrained immune responses can cause negative impacts such as damaging inflammation and slowed development. Here we find that a class of transcriptional regulators previously associated with regulation of development in Caenorhabditis elegans, is also involved in immune responses. Specifically, through forward genetics, we find that loss of lin-15B leads to constitutive expression of Intracellular Pathogen Response (IPR) genes. lin-15B encodes a transcriptional repressor with a conserved THAP domain that is associated with the DRM chromatin remodeling complex that regulates C. elegans development. We show that lin-15B mutants have increased resistance to natural intracellular pathogens, and the induction of IPR genes in lin-15B mutants relies on the MES-4 histone methyltransferase. We extend our analyses to other DRM and NuRD chromatin remodeling factors, as well as SUMOylation histone modifiers, showing that a broad range of chromatin-related factors can repress IPR gene expression. Altogether these findings suggest that conserved chromatin regulators may facilitate development in part by repressing damaging immune responses against intracellular pathogens. AUTHOR SUMMARYIn this study, we show that transcriptional regulators, previously linked to development in C. elegans, also control immune responses. Through forward genetic screens, we found that loss of LIN-15B leads to constitutive activation of Intracellular Pathogen Response (IPR) genes. LIN-15B is part of the DREAM chromatin remodeling complex, and its loss enhances resistance to intracellular pathogens. This immune response depends on the MES-4 histone methyltransferase. We also discovered that other chromatin regulators, including NuRD and SUMOylation factors, similarly repress IPR gene expression, highlighting a new role in immunity for these conserved regulators of development.

immunology↗

B cell c-Maf signaling promotes tumor progression in animal models of pancreatic cancer and melanoma

BackgroundThe role of B cells in anti-tumor immunity remains controversial, with studies suggesting the pro-tumor and anti-tumor activity. This controversy may be due to the heterogeneity in B cell populations, as the balance among the subtypes may impact tumor progression. The immunosuppressive regulatory B cells (Breg) release IL-10 but only represent a minor population. Additionally, tumor-specific antibodies (Ab) also exhibit anti-tumor and pro-tumor function dependent on the Ab isotype. Transcription factor c-Maf has been suggested to contribute to the regulation of IL-10 in Breg, but the role of B cell c-Maf signaling in anti-tumor immunity and regulating antibody responses remain unknown. MethodsConditional B cell c-Maf knockout (KO) and control mice were used to establish a KPC pancreatic cancer model and B16.F10 melanoma model. Tumor progression was evaluated. B cell and T cell phenotypes were determined by flow cytometry, mass cytometry, and cytokine/chemokine profiling. Differentially expressed genes in B cells were examined by using RNA-seq. Peripheral blood samples were collected from healthy donors and melanoma patients for B cell phenotyping. ResultsCompared to B cells from spleen and lymph nodes, B cells in the pancreas exhibited significantly less follicular phenotype and higher IL-10 production in naive mice. c-Maf deficiency resulted in a significant reduction of CD9+ IL-10-producing Breg in the pancreas. PDAC progression resulted in accumulation of circulating B cells with follicular phenotype and less IL-10 production in the pancreas. Notably, B cell c-Maf deficiency delayed PDAC tumor progression and resulted in pro-inflammatory B cells. Further, tumor volume reduction and increased effective T cells in the tumor-draining lymph node (TDLN) were observed in B cell c-Maf KO mice in the B16.F10 melanoma model. RNA-seq analysis of isolated B cells revealed that B cell c-Maf signaling modulates immunoglobulin (Ig)-associated genes and tumor specific antibody production. We furthermore demonstrated c-Maf-positive B cell subsets and increase of IL-10-producing B cells after incubation with IL-4 and CD40L in the peripheral blood of melanoma patients. ConclusionOur study highlights that B cell c-Maf signaling drives tumor progression through the modulation of Breg, inflammatory responses, and tumor-specific Ab responses. What is already known on this topicThe net effect of B cells on tumor immunity depends on the balance of various B cell subtypes. c-Maf has been suggested to contribute to the regulation of IL-10 in regulatory B cells (Breg), but the role of B cell c-Maf signaling in anti-tumor immunity remains unknown. What this study addsThis study shown that B cell c-Maf signaling drives tumor progression in pancreatic cancer and melanoma. We defined different anti-tumor mechanisms of B cell c-Maf deficiency in two tumor models. Specifically, c-Maf signaling modulates the pro-inflammatory phenotype of B cells in the KPC tumor-bearing pancreas and tumor-specific antibody responses in tumor draining lymph nodes (TDLN) of melanoma. How this study might affect research, practice or policyThese studies indicate that inhibition of c-Maf signaling is a novel and promising approach for immunotherapy in pancreatic cancer and melanoma.

immunology↗

TET2 contributes to gluconeogenesis and pathology of type 2 diabetes

The control of gluconeogenesis is critical for glucose homeostasis and the pathology of type 2 diabetes (T2D). Here, we uncover a novel function of TET2 in the regulation of gluconeogenesis. In mice, both fasting and a high-fat diet (HFD) stimulate the expression of TET2, and TET2 knockout impairs glucose production. Mechanistically, FBP1, a rate-limiting enzyme in gluconeogenesis, is positively regulated by TET2 in liver cells. TET2 is recruited by HNF4, contributing to the demethylation of FBP1 promoter and activating its expression in response to glucagon stimulation. Moreover, metformin treatment increases the phosphorylation of HNF4 on Ser313, which prevents its interaction with TET2, thereby decreasing the expression level of FBP1 and ameliorating the pathology of T2D. Collectively, we identify an HNF4-TET2-FBP1 axis in the control of gluconeogenesis, which contributes to the therapeutic effect of metformin on T2D and provides a potential target for the clinical treatment of T2D.

cell biology↗

Genomic stability in the Galapagos Scalesia adaptive radiation: Consistent transposable element accumulation despite hybridization and ecological niche shifts

Transposable elements (TEs) have been hypothesized to play a pivotal role in driving diversification by facilitating the emergence of novel phenotypes and the accumulation of divergence between species. Hybridization and adaptation to novel niches are hypothesized to influence TE accumulation in genomes by disrupting genomic regulation, including the suppression of TE replication. The rapid speciation and ecological diversification characteristic of adaptive radiations offer a unique opportunity to examine the link between TE accumulation and speciation, diversification, hybridization and adaptation. Here, focusing on all 15 species of the genus Scalesia (Asteraceae), a radiation endemic to the Galapagos Islands, we test whether hybridization or shifts in ecological niche are associated with changes in TE accumulation in genomes. Our analyses reveal little to no variation in TE accumulation among Scalesia species nor its hybrid populations. Shifts in ecological niches, linked to climatic variation, did not result in discernible changes in TE accumulation, a surprising finding given the anticipated selective pressure imposed by aridity, a factor often linked to genome size reduction. We found no distinct patterns in the temporal accumulation of TEs, and no effects at the class or superfamily level. Our findings challenge the assertion that TEs have directly driven diversification, speciation and local adaptation. Instead, we suggest that TEs may simply be along for the ride, rather than actively contributing to plant diversification.

evolutionary biology↗

Test-Retest Reliability and repeatability of Behavioral and Electrophysiological Markers in an Eriksen Flanker Task

Cognitive control processes, specifically interference control and error monitoring, are often impaired across neuropsychiatric disorders and have been proposed as transdiagnostic markers of psychopathology and important treatment targets. Accurately probing them, however, requires understanding the psychometric properties of the measures used to assess cognitive control, including their intra- and interindividual stability over time. Using an Eriksen Flanker Task, we tested behavioral and electrophysiological readouts of cognitive control in 36 healthy individuals (26 female, 10 male, M age{+/-}SD=33.18{+/-}14.49, range=19-68) and evaluated their test-retest reliability across 48 hours by calculating Pearson correlations and Intraclass Correlation Coefficients (ICCs) to assess group-level stability. Moreover, we assessed repeatability through Coefficients of Variation (CVs) and Bland-Altman statistics, to investigate the degree of change in participants absolute scores. We found satisfactory-to-excellent test-retest reliability for most cognitive control measures, with condition-specific metrics generally being more reliable than difference scores. Regarding repeatability, we observed considerable intraindividual variability in absolute scores over time, which differed widely between participants. These results demonstrate that measurements of cognitive control may display substantial intraindividual variability across sessions despite demonstrating high test-retest reliability and vice versa. Our findings expand the current literature by providing novel information about the stability of behavioral and physiological markers of cognitive control over time. Moreover, they may have important implications for the application and evaluation of clinical interventions by highlighting the usefulness of considering repeatability measures in addition to the more commonly reported test-retest reliability metrics, when tracking changes over time in clinically relevant processes within single individuals.

neuroscience↗

Expanding the CRISPR toolbox by engineering Cas12a orthologs of metagenomic discovery

Cas12a (Cpf1) is a CRISPR-associated nuclease with broad utility in genome editing and molecular diagnostic applications. However, the widespread adoption of CRISPR-Cas12a nucleases and their variants has been hindered by the requirement for a specific protospacer adjacent motif (PAM), relatively low CRISPR RNA (crRNA) activity and the inability to multiplex nucleic acid detection alone. To overcome these limitations, we employed a comprehensive framework combined with AlphaFold2 to de novo mine 1,261 previously unexploited Cas12a orthologs from the global microbiome. Following experimental analysis, we identified the most promising 21 Cas12a nuclease orthologs and designated them "Genie scissor 12" (Gs12). Our analysis uncovered two exceptional variants among these newly identified orthologs: Gs12-10, a first natural PAM-less Cas12a ortholog, which can recognize 52 distinct PAM types, representing a significant 1.8-fold expansion in recognition range compared to the relative LbCas12a PAM; and Gs12-7MAX, an engineered variant of Gs12-7 that exhibited 1.27-fold higher editing efficiency than enAsCas12a-HF. Furthermore, we harnessed Gs12-1, Gs12-4, Gs12-9, and Gs12-18, along with their corresponding engineered crRNAs, to develop a powerful four-channel multiplexed CRISPR-based nucleic acid detection system. The discovery of diverse functions in Cas12a offers a deeper understanding of the CRISPR/Cas12a family. Also, it holds great promise for expanding its applications and uncovering the untapped potential of other CRISPR/Cas systems. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=189 SRC="FIGDIR/small/615316v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@bee75forg.highwire.dtl.DTLVardef@1480f61org.highwire.dtl.DTLVardef@1e9cbc9org.highwire.dtl.DTLVardef@4211b2_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

GABAergic neuron dysregulation in a human neurodevelopmental model for major psychiatric disorders

"GABA dysfunction" is a major hypothesis for the biological basis of schizophrenia with indirect supporting evidence from human post-mortem brain and genetic studies. Patient-derived induced pluripotent stem cells (iPSCs) have emerged as a valuable platform for modeling psychiatric disorders, and previous modeling has revealed glutamatergic synapse deficits. Whether GABAergic synapse properties are affected in patient-derived human neurons and how this impacts neuronal network activity remain poorly understood. Here we optimized a protocol to differentiate iPSCs into highly enriched ganglionic eminence-like neural progenitors and GABAergic neurons. Using a collection of iPSCs derived from patients of psychiatric disorders carrying a Disrupted-in-Schizophrenia 1 (DISC1) mutation and their unaffected family member, together with respective isogenic lines, we identified mutation-dependent deficits in GABAergic synapse formation and function, a phenotype similar to that of mutant glutamatergic neurons. However, mutant glutamatergic and GABAergic neurons contribute differentially to neuronal network excitability and synchrony deficits. Finally, we showed that GABAergic synaptic transmission is also defective in neurons derived from several idiopathic schizophrenia patient iPSCs. Transcriptome analysis further showed some shared gene expression dysregulation, which is more prominent in DISC1 mutant neurons. Together, our study supports a functional GABAergic synaptic deficit in major psychiatric disorders.

neuroscience↗

Integrating various Experimental Information to Assist Protein Complex Structure Prediction by GRASP

Protein complex structures are essential for understanding of biological activities and drug development. Improving complex structure prediction accuracy of AI models for cases such as antigen-antibody complexes is expected to further enhance their applicability. Meanwhile, a large variety of experimental methods are used to provide structural insights for protein complexes, with only sparse or approximate knowledge obtained. A general tool is needed to integrate AI models with limited experimental information for high-throughput and accurate protein complex structure prediction. To efficiently and flexibly incorporate the different forms of experimental information, we introduce here GRASP. GRASP outperforms existing tools in handling both simulated and real-world experimental restraints including those obtained from XL, CL, CSP, and DMS. As an example, GRASP excels in predicting antigen-antibody complex structures, even surpassing AF3 when utilizing experimental DMS and CL restraints. In addition to accelerating the restrained modeling process, its ability to integrate multiple forms of restraints makes it capable of integrative modeling. We also showcase its potential in modeling protein structural interactome in the near-cellular condition based on large-scale in vivo XL data for mitchondria.

bioinformatics↗

SoyOD: An Integrated Soybean Multi-omics Database for Mining Genes and Biological Research

Soybean is a globally important crop for food, feed, oil, and nitrogen fixation. A variety of multi-omics research has been carried out generating datasets ranging from genotype to phenotype. To utilise this data, a soybean multi-omics database that has broad data coverage and comprehensive data analysis tools would be of value for basic and applied research. We present the soybean omics database (SoyOD), which integrates significant new datasets with existing public datasets for the most comprehensive collection of soybean multi-omics information. Compared to the existing soybean database, SoyOD incorporates an extensive collection of novel data derived from the deep-sequencing of 984 germplasms, 162 novel transcriptome datasets from seeds at different developmental stages, 53 phenotypic datasets, and over 2500 phenotypic images. In addition, SoyOD integrates existing data resources, including 59 assembled genomes, genetic variation data from 3904 soybean accessions, 225 sets of phenotypic data, and 1097 transcriptomic sequences covering 507 different tissues and treatment conditions. SoyOD is a novel tool, as it can be used to mine and analyze candidate genes for important agronomic traits, as shown in a case study on plant height. Additionally, powerful analytical and easy-to-use toolkits enable users to easily access the available multi-omics datasets, and to rapidly search genotypic and phenotypic data in a particular germplasm. The novelty, comprehensiveness, and user-friendly features of SoyOD make it a valuable resource for soybean molecular breeding and biological research. SoyOD is publicly accessible at https://bis.zju.edu.cn/soyod.

plant biology↗

Successful stimulation of myocardial ganglionic plexuses by TAU 20 in the absence of cardiac damage

Atrial fibrillation (AF) is a major healthcare burden worldwide. For AF that is resistant to pharmacological intervention, the standard invasive treatment is a pulmonary vein isolation (PVI) procedure. Ganglionated plexuses (GP) ablation can be used as an adjunctive therapy to PVIs, together reducing the likelihood of AF recurrence. High-frequency stimulation (HFS) is a technique used to identify ectopy-triggering GP sites. However, to locate GP sites, sequential HFS must be delivered over the whole atria. Therefore, ensuring the safety of HFS delivery is integral to avoid causing irreversible damage from excessive pacing. We tested Tau-20 version 2 neural simulator, a prototype of a novel electrophysiological pacing and recording system that has the potential to guide intracardiac AF treatments. Using an ex vivo porcine Langendorff model that closely resembles the anatomy and physiology of a human heart, we confirmed that HFS can successfully trigger AF, indicating that HFS-positive locations contain GP sites. Additionally, we found that the HFS delivered via Tau-20 version 2 did not cause any damage to the heart. These findings evidence that once fully optimised, the Tau-20 system could be suitable for use in clinical settings.

physiology↗

Deleting PTEN, but not SOCS3 or myelin inhibitors, robustly boosts BRAF-elicited intraspinal regeneration of peripheral sensory axons

Primary sensory axons fail to regenerate into the spinal cord after dorsal root (DR) injury, resulting in persistent sensory deficits. This regenerative failure occurs at the dorsal root entry zone (DREZ), the CNS-PNS interface where injured sensory axons encounter both extrinsic inhibitory cues and a limited intrinsic growth state. Although several approaches have promoted partial DR regeneration across the DREZ, sustained long-distance regeneration, particularly of large-diameter myelinated axons, remains a major challenge. We previously showed that induced expression of constitutively active B-RAF (kaBRAF) increases the regenerative competence of injured adult DRG neurons. Here, we tested whether robust intraspinal regeneration after cervical DR injury could be achieved by selective kaBRAF expression alone or in combination with removal of myelin-associated inhibitors or deletion of neuron-intrinsic growth suppressors, PTEN or SOCS3. kaBRAF promoted reproducible but limited regeneration across the DREZ and did not produce significant functional recovery by two months. Additional deletion of Nogo, MAG, and OMgp produced only a modest improvement in kaBRAF-mediated regeneration. Deletion of PTEN or SOCS3, either alone or together, failed to promote meaningful growth across the DREZ. In contrast, PTEN deletion dramatically enhanced kaBRAF-mediated regeneration, enabling many axons to penetrate the DREZ and grow deep into the spinal cord, whereas SOCS3 deletion provided little additional benefit. These findings identify combined activation of BRAF-MEK-ERK and PI3K-Akt-mTOR signaling as a powerful strategy for stimulating robust intraspinal regeneration of injured DR axons.

neuroscience↗

A T6SS DNase effector induces nuclear DNA Damage to trigger apoptosis via activation of the cGAS-STING-TNF axis

In the relentless battle for survival, bacteria have evolved sophisticated weaponry like the Type VI secretion system (T6SS) to not only outcompete rivals but also manipulate host cell processes to their advantage. Apoptosis, a controlled form of programmed cell death without triggering inflammatory responses, is often exploited by pathogens. While many bacterial pathogens are known to induce apoptosis, the role of T6SS effectors in this process remains unexplored. In this study, we discovered that Yersinia pseudotuberculosis (Yptb) utilizes its T6SS to secrete a DNase effector, TkeA, which induces apoptosis in host cells. Mechanistically, the translocation of TkeA into host cells causes nuclear DNA damage, leading to the release of fragmented DNA into the cytoplasm. This, in turn, activates the DNA-sensing cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) pathway. The activation of the cGAS-STING pathway by TkeA subsequently triggers apoptosis in host cells via extrinsic pathways, with tumor necrosis factor (TNF) signaling playing a critical role. Additionally, TkeA also mediates interbacterial competition, promoting the colonization of Yptb in mices gut. Our findings reveal that the T6SS-secreted DNase effector TkeA acts as a trans-kingdom effector, enhancing interbacterial competition and inducing apoptosis in host cells by activating the cGAS-STING-TNF axis. This discovery adds a new dimension to the mechanisms employed by bacterial pathogens to manipulate host cell death pathways by using their secretion systems. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/613802v1_ufig1.gif" ALT="Figure 1"> View larger version (62K): org.highwire.dtl.DTLVardef@1bfd70org.highwire.dtl.DTLVardef@19bfc89org.highwire.dtl.DTLVardef@1e0bf9dorg.highwire.dtl.DTLVardef@4412b9_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTS* Yptb T6SS secretes a trans-kingdom DNase effector TkeA * TkeA degrades bacterial DNA to mediate interbacterial competition * TkeA causes nuclear DNA damage in host cells to induce apoptosis * TkeA induces apoptosis via the cGAS-STING-TNF axis

microbiology↗

eDNA sampling systems for salmon ecosystem monitoring

Environmental DNA (eDNA) is transforming the way aquatic ecosystems are monitored and managed by scientists, resource managers, ENGOs, First Nations communities, and citizen scientists alike. However, the lack of sampling systems enabling high filtration volumes and rapid sample collection in the field have thus far hindered broad scale eDNA studies in the ocean specifically for small and medium scale organizations. To overcome these challenges, several modular water sampling systems that utilize hollow-membrane filtration cartridges were developed by RKS laboratories and tested by the Fisheries and Oceans, Canada, Molecular Genetics Laboratory. Compared to Sterivex filters, an industry standard for eDNA filtration, the hollow-membrane filtration cartridges allowed for a six-fold increase in filtration volume and threefold increase in filtration speed. The field sampling systems, which combine pumps, a programmable controller, an air pump, an ozone generator, and up to eight filters at once, enabled efficient direct eDNA filtration from diverse aquatic environments, from creeks to the open ocean. To evaluate ease of deployment, we present the results of a three day workshop where technical staff of an Indigenous resource management organization, without any prior knowledge in eDNA sampling, were trained and performed independent eDNA sample collection. The samples were analyzed by metabarcoding and qPCR to reveal the distributions of salmon and other species co-occurring in salmon ecosystems, from large ephemeral predators, to the planktonic prey of salmon, even including their pathogens. In this example study, we further observed a substantial shift in community composition in the vicinity of aquaculture facilities where marine species associated with aquaculture feed were detected in freshwater at high relative abundance. This study demonstrates how these sampling systems provide an efficient entry point for small and medium scale organizations to utilize eDNA to fulfill their research and monitoring objectives.

genomics↗

53BP1 deficiency leads to hyperrecombination using break-induced replication (BIR)

Break-induced replication (BIR) is mutagenic, and thus its use requires tight regulation, yet the underlying mechanisms remain elusive. Here we uncover an important role of 53BP1 in suppressing BIR after end resection at double strand breaks (DSBs), distinct from its end protection activity, providing insight into the mechanisms governing BIR regulation and DSB repair pathway selection. We demonstrate that loss of 53BP1 induces BIR-like hyperrecombination, in a manner dependent on Pol-primase-mediated end fill-in DNA synthesis on single-stranded DNA (ssDNA) overhangs at DSBs, leading to PCNA ubiquitination and PIF1 recruitment to activate BIR. On broken replication forks, where BIR is required for repairing single-ended DSBs (seDSBs), SMARCAD1 displaces 53BP1 to facilitate the localization of ubiquitinated PCNA and PIF1 to DSBs for BIR activation. Hyper BIR associated with 53BP1 deficiency manifests template switching and large deletions, underscoring another aspect of 53BP1 in suppressing genome instability. The synthetic lethal interaction between the 53BP1 and BIR pathways provides opportunities for targeted cancer treatment.

molecular biology↗

High-coverage, massively parallel sequencing of single-cell genomes with CAP-seq

Microbial communities are extraordinarily diverse and play crucial roles in health and disease, yet current methods lack the resolution and scalability needed to dissect their genomic and ecological complexity at the single-cell level. Here, we present CAP-seq, a high-throughput single-microbe genomics platform that combines hydrogel-based semi-permeable encapsulation with minimal microfluidics to recover thousands of single-amplified genomes (SAGs) with long reads and high completeness at low sequencing depth. We benchmarked CAP-seq using defined microbial communities, demonstrating strain-level resolution, accurate detection of rare taxa, and genome recovery exceeding 50% at [~]10x coverage. Applying CAP-seq to pediatric Clostridioides difficile infection microbiomes, we generated a high-resolution single-cell atlas comprising tens of thousands of SAGs across hundreds of species. Host-resolved profiling of the cryptic plasmid pBI143 revealed previously hidden low-abundance host associations, six new plasmid versions, and their coexistence within individuals, indicating complex plasmid evolution in situ. Longitudinal analysis during fecal microbiota transplantation and vancomycin treatment uncovered dynamic remodeling of microbial hosts, antimicrobial resistance genes, and plasmids at single-cell resolution. CAP-seq enables scalable, high-performance single-cell genomics and provides a practical, widely accessible platform for microbiome analysis, paving the way for large-scale exploration of microbial dark matter and host-microbe interactions across diverse ecosystems.

genomics↗

LYMTACs: Chimeric Small Molecules Repurpose Lysosomal Membrane Proteins for Target Protein Relocalization and Degradation

Proximity-inducing modalities that co-opt cellular pathways offer new opportunities to regulate oncogenic drivers. Inspired by the success of proximity-based chimeras in both intracellular and extracellular target space, here we describe the development of LYsosome Membrane TArgeting Chimeras (LYMTACs) as a novel small molecule-based platform that functions intracellularly to modulate the membrane proteome. Conceptually, LYMTACs are heterobifunctional small molecules that co-opt short-lived lysosomal membrane proteins (LMPs) as effectors to deliver targets for lysosomal degradation. We demonstrate that a promiscuous kinase inhibitor-based LYMTAC selectively targets membrane proteins for lysosomal degradation via RNF152, a short-lived LMP. To extend these findings, we show that oncogenic, membrane-associated KRASG12D protein can be tethered to RNF152, inducing KRAS relocalization to the lysosomal membrane, inhibiting downstream phospho-ERK signaling, and leading to lysosomal degradation of KRASG12D in a LYMTAC-dependent manner. Notably, potent cell killing could be attributed to the multi-pharmacology displayed by LYMTACs, which differentiates the LYMTAC technology from existing modalities. Thus, LYMTACs represent a proximity-based therapeutic approach that promises to expand the target space for challenging membrane proteins through targeted protein relocalization and degradation.

cancer biology↗

The Structure of Cilium Inner Junctions Revealed by Electron Cryo-tomography

The cilium is a microtubule-based organelle critical for many cellular functions. Its assembly initiates at a basal body and continues as an axoneme that projects out of the cell to form a functional cilium. This assembly process is tightly regulated. However, our knowledge of the molecular architecture and the mechanism of assembly is limited. By applying electron cryo-tomography and subtomogram averaging, we obtained subnanometer resolution structures of the inner junction in three distinct regions of the cilium: the proximal region of the basal body, the central core of the basal body, and the flagellar axoneme. The structures allowed us to identify several basal body and axoneme components. While a few proteins are distributed throughout the entire length of the organelle, many are restricted to particular regions of the cilium, forming intricate local interaction networks and bolstering local structural stability. Finally, by knocking out a critical basal body inner junction component Poc1, we found the triplet MT was destabilized, resulting in a defective structure. Surprisingly, several axoneme-specific components were found to "infiltrate" into the mutant basal body. Our findings provide molecular insight into cilium assembly at its inner junctions, underscoring its precise spatial regulation.

cell biology↗