Biology subjects

Watanabe, S.

Publications and source records attributed to Watanabe, S..

At least 19 recordsLinked to original sources

bioRxiv2026

A High-Sensitivity and High-Throughput LC-MS Workflow for Low-Input and Single-Cell Proteomics

Single-cell proteomics (SCP) requires sample preparation that minimizes sample loss and highly sensitive LC-MS analysis because the amount of protein available from a single cell is extremely limited. Here, we developed an integrated workflow for low-input and single-cell proteomics based on single-cell proteomics by LMNG-assisted sample preparation (scpLASP), which enables microliter-scale sample preparation using standard laboratory consumables. Systematic optimization of peptide reconstitution conditions identified 0.01% n-dodecyl-{beta}-D-maltoside (DDM) combined with 0.01% lauryl maltose neopentyl glycol (LMNG) as the condition yielding the highest number of identified peptides among those tested for low-input samples. Optimization of the LC mobile-phase composition identified 0.5% acetic acid with 1% dimethyl sulfoxide (DMSO) as the optimal condition, increasing the mean number of identified protein groups from 6,767 with 0.1% formic acid to 7,409 for 250 pg HeLa digests analyzed using an Orbitrap Astral Zoom. Shortening the LC gradient from 11 to 5.5 min enabled higher analytical throughput while maintaining mean identification counts of 6,558 and 7,088 protein groups from 100 and 250 pg HeLa digests, respectively, with median protein-level coefficients of variation of 9.20% and 6.99%. When the optimized workflow was applied to HEK293-derived Expi293F single cells using the same 5.5-min LC gradient, an effective analytical throughput of 135 samples per day was achieved with an injection volume of 4.5 {micro}L, accounting for sample-loading time. This workflow identified a median of 5,655 protein groups per cell using an empirical spectral library generated from 20-cell samples. Overall, this study establishes a sensitive and high-throughput workflow for low-input and single-cell proteomics that combines low-loss microliter-scale sample preparation with optimized LC-MS analysis, achieving high proteome depth and analytical throughput without requiring specialized nanoliter-scale sample-preparation devices.

biochemistry↗

bioRxiv2026

Root-to-shoot ABA transport by NPF2.4 and NPF2.5 links stomatal regulation to photosynthetic performance

Fluctuating light strongly limits photosynthetic efficiency in plants, yet the mechanisms coordinating stomatal dynamics with rapid photosynthetic induction remain incompletely understood. Here, through a forward physiological screen in Arabidopsis, we identify the abscisic acid (ABA) transporters NPF2.4 and NPF2.5 as regulators of photosynthetic responses to fluctuating light. Loss-of-function npf2.4 and npf2.5 mutants exhibited accelerated stomatal opening and photosynthetic induction during light transitions, resulting in enhanced biomass accumulation and seed yield without compromising long-term drought tolerance. NPF2.4 and NPF2.5 mediated ABA uptake in yeast and were predominantly expressed in the root pericycle and cortex/epidermal tissues, respectively. Reciprocal grafting, xylem sap ABA measurements, and ABA treatment to the roots demonstrated that both transporters regulate root-to-shoot ABA transport. Our findings reveal that root-derived ABA modulates stomatal dynamics and photosynthetic efficiency under fluctuating light, establishing long-distance hormone transport as a key regulator of plant carbon gain in dynamic environments.

plant biology↗

bioRxiv2026

HY5 orchestrates the transcriptional network controlling coumarin-mediated iron acquisition under elevated pH conditions

Iron (Fe) bioavailability is strongly limited in alkaline soils, where reduced Fe solubility severely restricts plant growth and productivity. To overcome this, Arabidopsis thaliana promotes Fe acquisition by secreting Fe-mobilizing coumarins, however, the transcriptional mechanisms coordinating this response is not clearly understood. Here we identify the ELONGATED HYPOCOTYL 5 (HY5), a bZIP transcription factor as a master regulator of coumarin mediated Fe acquisition under alkaline conditions. HY5 positively regulates genes required for coumarin biosynthesis, activation, secretion, and transcriptional control, and loss of HY5 markedly reduces their expression during high-pH-induced Fe deficiency. Chromatin immunoprecipitation analyses revealed that HY5 directly associates with the promoters of these genes, thereby establishing a transcriptional regulatory network that coordinates coumarin biosynthesis. Consistent with this regulatory function, hy5 mutants exhibit reduced coumarin accumulation, impaired root growth, chlorosis, and decreased Fe accumulation under alkaline conditions. Comparable phenotypes in coumarin-hy5 double mutants, together with the restoration of growth by exogenous fraxetin, demonstrate that HY5 functions upstream of coumarin-mediated Fe mobilization. Collectively, our findings identify HY5 as a molecular hub that integrates environmental pH signals with coumarin biosynthesis to promote adaptive Fe acquisition under alkaline conditions, providing a framework for improving crop performance on calcareous soils.

plant biology↗

bioRxiv2026

MYB28 and MYB29 transcription factors regulate iron homeostasis and iron-mobilizing coumarin biosynthesis in Arabidopsis thaliana

Iron (Fe) deficiency is a major constraint for plant growth and triggers extensive physiological and transcriptional reprogramming to maintain Fe homeostasis. Here, we identify the glucosinolate-associated transcription factors MYB28 and MYB29 as previously unrecognized regulators of Arabidopsis thaliana adaptation to Fe deficiency. Across various growth systems, loss of MYB28 increased sensitivity to Fe deficiency, whereas the myb28myb29 double mutant displayed stronger chlorosis, reduced root growth and impaired biomass accumulation, indicating cooperative but unequal functions of these transcription factors. Despite their enhanced Fe-deficiency phenotype, double mutant plants accumulated higher Fe levels in roots and exhibited stronger induction of canonical Fe-deficiency responses, suggesting impaired Fe utilization or distribution rather than defective Fe uptake. RNA-seq revealed extensive transcriptional reprogramming under Fe deficiency, with pronounced deregulation of genes involved in Fe homeostasis, redox processes and growth, particularly in the double mutant. Among these, SCOPOLETIN 8-HYDROXYLASE (S8H) emerged as a major target gene of MYB28. The expression of S8H was almost abolished in myb28 and myb28myb29 mutants, whereas expression of other coumarin biosynthetic genes remained largely unaffected. Promoter activation assays demonstrated that MYB28 activates the S8H promoter, and metabolic analyses showed accumulation of scopolin together with reduced fraxin levels in the mutants, consistent with impaired S8H activity. Collectively, our results identify MYB28 as a key regulator linking specialized metabolism to Fe homeostasis through control of coumarin biosynthesis, thereby expanding the biological functions of MYB28 and MYB29 transcription factors.

plant biology↗

bioRxiv2026

Microglia extract neuronal proteolytic organelles via skoupocytosis

Neurons face unique challenges in maintaining protein homeostasis due to their tortuous morphology and extended processes. Proteolytic organelles are typically transported retrogradely towards their soma for degradation where lysosomes are enriched, but some organelles are larger than these neuronal processes, questioning how these organelles are degraded. Here we show that microglia, the resident immune cells of the brain, extract proteolytic organelles from neurons both in vitro and in vivo. Microglia make transient contact with neuronal membranes where proteolytic organelles are stationed beneath. At these sites of interaction, microglia pinch off a small portion of the neuronal process containing the organelle, leaving the rest of the process intact. We term this process skoupocytosis after the Greek word for garbage. Phosphatidylserine (PS) lipase ABHD16a accumulates near these proteolytic organelles and converts PS into lyso-PS to initiate microglial skoupocytosis. Skoupocytosis bypasses the need for retrograde organelle transport, providing homeostatic advantages for neurons that must maintain function in processes that extend extraordinarily long distances from the cell soma.

neuroscience↗

bioRxiv2026

Water stress adaptive responses in plants require movement of ABA and AB-aldehyde from vascular to target tissues

Vascular plants rapidly coordinate root and shoot responses to water stress. Abscisic acid (ABA) mediates these adaptations; however, it remains unclear which cells produce ABA, whether ABA synthesis shifts during stress, and whether ABA movement is required for its adaptive functions. Here, we map ABA biosynthesis at cellular resolution in Arabidopsis and report that water-stress adaptive responses in roots and shoots require movement of ABA and its precursor AB-aldehyde from vascular tissues to target cells. We suggest that ABA accumulation arises from two parallel routes: (i) ABA synthesized in the vasculature via ABA2 and AAO3, then moving to guard cells, and (ii) phloem-derived AB-aldehyde being converted to ABA in the epidermis or bundle sheath by AAO1 and AAO2. Finally, we predict that tightly packed cells beneath leaf veins facilitate efficient ABA delivery to guard cells, an anatomical arrangement that has enabled angiosperms to evolve the use of ABA to rapidly close stomata.

plant biology↗

bioRxiv2026

Generation of lachrymatory factor synthase-suppressed onion (Allium cepa L.) by Agrobacterium-mediated gene transfer for CRISPR/Cas9 genome editing

Lachrymatory factor, an irritating volatile with tear-inducing property, is produced when onion bulbs are cut or chopped. We aimed to generate onion plants with reduced lachrymatory factor synthase (LFS) activity via clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9 (CRISPR/Cas9) genome editing. Calli induced from primary roots were transformed with Agrobacterium tumefaciens carrying expression cassettes for CRISPR/Cas9, guide RNA, green fluorescent protein (GFP), and hygromycin resistance; callus lines that showed a high-frequency stable GFP expression were selected as "elite callus lines" that were suitable for transformation. Cleaved amplified polymorphic sequence (CAPS), heteroduplex mobility assay (HMA), and Sanger sequencing confirmed mutations introduced into the LFS gene, and plants were regenerated from the confirmed LFS-edited callus lines. The LFS enzyme activity in the leaves and bulbs of the LFS-edited plants was lower than that in control plants, while the LFS-edited plants exhibited severe growth abnormalities and failed to set seed, possibly due to long-term culture to maintain the elite callus line. The present study first demonstrated that onion genome editing, which modified a specific trait of onion, the reduction of LFS activity, was achieved. The results obtained opened the feasible way toward the final goal: the production of tear-free, higher health-functional onions.

plant biology↗

bioRxiv2026

Dysregulated flow responses drive pathogenesis in a cellular model of Sturge-Weber syndrome

Vascular diseases comprise a broad spectrum of conditions associated with organ dysfunction, yet how endothelial responses to mechanical forces drive their pathogenesis remains unclear. Sturge-Weber syndrome (SWS), a flow-associated vascular malformation caused by somatic GNAQ mutations, provides a model to investigate this question. Here, using isogenic induced pluripotent stem cell-derived endothelial cells (ECs), perfusable vascular models, and simplified systems under defined flow conditions, we show that SWS ECs exhibited maladaptive responses to laminar flow, including impaired flow alignment, reduced CLDN5 expression, and decreased transendothelial electrical resistance. Importantly, three-dimensional acoustic microscopy uncovered disturbed surface changes in SWS ECs, potentially contributing to changes in mechanosensing signaling. Transcriptomic and chromatin accessibility analyses revealed dysregulated flow-responsive gene programs, some of which were validated in human SWS samples. These findings provide insights into flow-dependent endothelial dysfunction and a framework for therapeutic modulation in SWS and other vascular disorders.

cell biology↗

bioRxiv2026

Perm1 Gene Therapy Mitigates PRDM16-Associated Cardiomyopathy

BackgroundPathogenic variants in PR domain containing 16 (PRDM16) cause pediatric and adult cardiomyopathies characterized by ventricular dilation, systolic dysfunction, and impaired metabolic maturation. Cardiac deficiency of PRDM16 alters metabolic gene expression and long-chain fatty acid (FA) metabolites. However, the downstream mediators involved are not well characterized. Furthermore, whether improving mitochondrial FA metabolism can prevent PRDM16-associated cardiomyopathy is currently unknown. MethodsIn vivo and in vitro approaches using patient-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) and mouse models with Prdm16 deletion/mutation were employed. Transcriptomics and proteomics analyses were conducted, and adeno-associated virus (AAV)-mediated therapy was tested. ResultsHere, we show that a defect in FA metabolism is an early hallmark of PRDM16 cardiac deficiency. We show, for the first time, that PERM1 is a direct downstream target of PRDM16 and is involved in the regulation of FA metabolism through coordinated action with PGC1. Most importantly, neonatal delivery of AAV9-Perm1 in cardiac-specific Prdm16 knockout (Prdm16 cKO) mice markedly improved contractile parameters, reduced left ventricular (LV) dilation, and extended survival. These cardioprotective effects of PERM1 gene therapy occurred independent of restoring FA oxidation. Transcriptional and proteomic analyses of AAV-Perm1-treated Prdm16 cKO mice demonstrated significant improvements in mitochondrial cristae architecture, preservation of sarcomere organization, reduced cardiomyocyte apoptosis, attenuated myocardial fibrosis, and diminished cardiac remodeling. ConclusionsWe identify PERM1 as a direct downstream effector of PRDM16 and uncover a previously unrecognized PRDM16-PGC1-PERM1 axis essential for FA metabolic regulation in the heart. Perm1 gene therapy ameliorated PRDM16-associated cardiomyopathy through post-transcriptional mechanisms involving preservation of mitochondrial and sarcomere integrity. The current study provides preclinical evidence suggesting that Perm1 gene therapy may be a promising therapeutic target to improve the cardiac outcomes of patients affected by pathogenic PRDM16 variants.

physiology↗

bioRxiv2026

Females are protected from semaglutide-induced muscle loss in ob/ob mice

Obesity is a major contributor to cardiometabolic disease, and pharmacological therapies such as semaglutide are increasingly used to induce weight loss. However, the commonly used diet-induced obesity model in C57BL/6J mice is limited by relative resistance to weight gain in females, complicating the study of sex-specific effects. Here, we used leptin-deficient ob/ob mice, which develop severe early-onset obesity in both sexes, to investigate sex-specific responses to semaglutide on skeletal muscle mass, function, and mitochondrial metabolism. The ob/ob mice were treated daily with semaglutide or vehicle for three weeks, followed by assessments of body composition, muscle and organ mass, muscle contractile function, and mitochondrial efficiency. Semaglutide induced comparable reductions in body weight and food intake in both sexes but elicited distinct sex-specific changes in body composition. Male mice exhibited losses in both skeletal muscle and organ mass, whereas female mice preferentially lost fat and organ mass while preserving skeletal muscle. Despite these divergent structural adaptations, muscle force generation remained intact in both sexes. Collectively, these findings reveal pronounced sexual dimorphism in skeletal muscle and metabolic remodeling during pharmacologically induced weight loss, highlighting the importance of considering biological sex when evaluating the metabolic and therapeutic effects of anti-obesity interventions. Article HighlightO_LIC57BL/6J mice are limited by relative resistance to weight gain in females, complicating the study of sex-specific effects. So, we wanted to determine the sex-specific effect of semaglutide on skeletal muscle function, and mitochondrial metabolism in ob/ob mice. C_LIO_LIWe assessed body composition and ex-vivo muscle force following the treatment and found that the female ob/ob mice are protected from semaglutide-induced skeletal muscle mass loss. C_LIO_LIThese findings demonstrate sex-specific effects of semaglutide, highlighting the need to consider biological sex in GLP-1RA-based therapies. C_LI

physiology↗

bioRxiv2026

Near real-time data on the human neutralizing antibody landscape to influenza virus as of early 2026 to inform vaccine-strain selection

Twice each year, a decision is made on whether to update the strains included in the seasonal influenza vaccine to better match the most recent circulating viral strains. To characterize the antigenic properties of current seasonal influenza A strains to inform the upcoming decision about which strains to include in the 2026-2027 Northern Hemisphere vaccine, here we perform high-throughput sequencing-based neutralization assays using a library of 57 H3N2 and 34 H1N1 influenza hemagglutinins reflecting the circulating diversity of strains in late 2025 to early 2026. We assay this library against 302 human sera collected in late 2025. The resulting data set encompasses 27,409 titers, and provides a near real-time portrait of the human neutralizing antibody landscape against influenza virus. We find that many human sera have lower titers against the K subclade of H3N2 and the D.3.1.1 subclade of H1N1; these subclades have recently become dominant among their respective subtypes. Our measurements also reveal variability in titers to different subvariants within the K subclade of H3N2, with titers especially low to subclade K strains with additional mutations in antigenic regions D and E. We make all our data and accompanying visualizations publicly available to enable their use in vaccine-strain selection and analyses of influenza evolution and immunity.

microbiology↗

bioRxiv2026

An ancient monoaminergic signaling system coordinates contractility in a nerveless sponge

Chemical neurotransmission was a key animal innovation, enabling multicellular coordination of physiology and locomotion. Sponges are early-diverging animals that lack neurons and muscles, yet still coordinate contraction and relaxation of their filter-feeding water canals. Here, we show that Spongilla lacustris synthesizes the monoamines tryptamine, phenethylamine, and tyramine to elicit distinct canal behaviors. We identify previously uncharacterized decarboxylases and vesicular transporters coexpressed in secretory neuroid and metabolic cells. Using phosphoproteomics and label-free 3D imaging, we show that tryptamine activates GPCR signaling and Rho GTPases, remodeling adhesion and actomyosin networks in contractile canal epithelia to drive localized constrictions and whole-body deflations. Together, these findings define an ancestral monoaminergic system linking secretory and contractile cell types that predate neurons and was later elaborated for neuromodulation of synaptic transmission.

evolutionary biology↗

bioRxiv2025

Transfer of the synechan biosynthesis and regulatory pathway enables sulfated polysaccharide production in Synechococcus elongatus PCC 7942

Many sulfated polysaccharides (SPSs) possess useful physicochemical properties and biological activities and are widely used in industry. Currently, major SPSs are derived from livestock and marine organisms. To contribute both to addressing global environmental challenges and to the development of diverse SPSs, microbial production systems are therefore required. Nevertheless, bacteria capable of producing SPSs are limited. In contrast, many cyanobacteria synthesize diverse SPSs, making them promising hosts to produce valuable SPSs, sources for novel SPSs, and genetic resources for SPS biosynthesis. However, no study has introduced an entire heterologous SPS biosynthetic system into cyanobacteria to produce a heterologous SPS. We recently identified a novel SPS, synechan, and elucidated the genetic basis for the biosynthesis and regulation of cyanobacterial SPSs. Here, we heterologously expressed the gene set responsible for synechan biosynthesis and its regulation in the non-SPS-producing cyanobacterium Synechococcus elongatus PCC 7942 and successfully induced the production of an SPS. This work provides a foundation for engineering cyanobacteria to produce useful SPSs and, to our knowledge, the first functional heterologous reconstitution in cyanobacteria of a large gene cluster encoding a complex membrane-associated biosynthetic system and thus an important step in synthetic-biology-based engineering of cyanobacteria.

synthetic biology↗

bioRxiv2025

Influenza A infection accelerates disease-associated microglia formation during physiological aging

Severe pneumonia is associated with an increased risk of cognitive decline and dementia, particularly in the elderly. Changes in microglia, the most abundant immune cell population in the brain, are also associated with cognitive decline and dementia, including the emergence of a transcriptional cell state referred to as disease-associated microglia (DAM). We sought to test the hypothesis that non-neuroinvasive influenza A virus (IAV) pneumonia results in transcriptional responses in brain microglia that drive premature expansion of DAM. Using bulk and single-cell RNA-sequencing, metabolomics, and spatial transcriptomics, we profiled neuroimmune populations in young, middle-aged, and old male mice during IAV infection and recovery. We observed an increased abundance of DAM, interferon-responsive microglia (IRM), CD4+ T cells, and CD8+ T cells in white matter regions beginning in middle age and persisting in old animals, irrespective of IAV infection. DAM exhibited a metabolic shift toward aerobic glycolysis with disrupted TCA cycling, citrulline depletion, and an elevated itaconate/-ketoglutarate ratio. Spatial transcriptomic profiling of the human middle frontal gyrus (MFG) in normal agers, SuperAgers, and patients with dementia revealed an analogous accumulation of DAM and CD8+ T cells in white matter. IAV pneumonia induced a transient immunosenescent-like response in microglia, marked by glucocorticoid-responsive gene expression and Ccnd3 upregulation. In response to IAV pneumonia, DAM expanded in middle-aged mice, whereas old mice were elevated at baseline and were largely unaffected by IAV infection. The age-related expansion of DAM was unaffected by pharmacological depletion and repopulation of microglia with a CSF1R antagonist or genetic gain or loss of function of the phagocytic receptor MERTK, suggesting the DAM phenotype is driven by the CNS microenvironment, rather than cell-intrinsic mechanisms. Our findings suggest that IAV pneumonia induces an acute immunosenescence response in microglia and accelerates the age-dependent expansion of DAM in white matter.

neuroscience↗

bioRxiv2025

CFDP1 is required for histone variant H2A.Z deposition by the human SRCAP chromatin remodeling complex

Craniofacial Developmental Protein 1 (CFDP1) is a member of the evolutionarily conserved family of Bucentaur (BCNT) proteins and was originally classified as a protein required for cell survival and differentiation during tooth development. Yeast Swc5, a BCNT family member, is an essential subunit of the yeast SWR1C chromatin remodeling complex that catalyzes the deposition of histone variant H2A.Z. Direct connections between CFDP1, H2A.Z deposition, and the mammalian SWR1 homolog, Snf2-Related CREBBP Activator Protein (SRCAP), have not been identified. Here, we perform detailed biochemical reconstitution and characterization of the human SRCAP complex (SRCAP-C). We find that CFDP1 weakly interacts with SRCAP-C in a salt concentration-dependent manner. SRCAP-C purified under a high-salt condition does not co-purify with CFDP1 and is inactive in H2A.Z dimer exchange reaction, but the addition of exogeneous CFDP1 restores the H2A.Z deposition activity of SRCAP-C, demonstrating that CFDP1 is required for H2A.Z dimer exchange by SRCAP-C. We show that CFDP1 stimulates the basal ATPase activity of reconstituted SRCAP-C, suggesting a requirement for CFDP1 in regulating intrinsic catalytic ATPase activity. Consistent with this idea, CFDP1 deficiency in human induced pluripotent stem cells (hiPSCs) leads to a genome-wide reduction of H2A.Z, H3K27me3, and H3K4me3 deposition, accompanied by the upregulation of developmental genes normally marked by these modifications. Taken together, our results provide mechanistic insights into how CFDP1 regulates histone variant H2A.Z deposition by SRCAP-C. Given mutations in the SRCAP gene cause Floating-Harbor syndrome (FHS), a rare, dominant developmental disorder, our study provides an additional link between craniofacial defects and SRCAP-mediated H2A.Z deposition.

molecular biology↗

bioRxiv2025

Sexual life cycle establishes the unicellular red algae Cyanidiophyceae as a genetically tractable model lineage for eukaryotic evolution

The thermo-acidophilic unicellular algal class Cyanidiophyceae is the earliest-branching lineage in red algae, which diverged from Viridiplantae lineage (green algae and land plants) soon after chloroplast establishment in the common ancestor of Archaeplastida. Cyanidiophyceae possess extremely simple genomes (8.7-17.8 Mb; approximately 4,800- 7,800 genes), and the cell-wall-less, genetically tractable strain Cyanidioschyzon merolae 10D has served as a model organism. However, its unknown sexual life cycle has limited its utility in studies of evolution and genetics. Inspired by the recent discovery of sexual reproduction in the cyanidiophycean genus Galdieria, we identified similar life cycles in the other cyanidiophycean genera Cyanidioschyzon, Cyanidiococcus, and Cyanidium. In these genera, the cell-walled diploid form, exclusively observed in nature, produces a cell-wall-less haploid form when the culture pH is lowered, and both proliferate asexually. In addition, the cell-wall-less Cyanidioschyzon merolae 10D strain has been shown to be a haploid clone that forms a cell-walled diploid through mating with other haploid clones. Building on these findings, we generated high-quality genomic resources with phase-specific transcriptomes and developed genetic manipulation systems using the cell-wall-less haploids of these genera. We further uncovered phase-specific distribution of histone H3 lysine 27 trimethylation linked to haploid- and diploid-specific gene expression, including transcription factors involved in differentiation associated with sexual reproduction in plants. Additionally, biparental inheritance of organelle DNA occurs following isogamous mating of haploid cells but resolves into uniparental inheritance during diploid proliferation. These advances position Cyanidiophyceae as a powerful model lineage for studying early Archaeplastida evolution, the shared mechanisms of photosynthetic eukaryotes, and their environmental adaptation.

plant biology↗

bioRxiv2025

Transcytosis-mediated anterograde transport of TrkA receptors controls formation of presynaptic sites in sympathetic neurons

In neurons, many membrane proteins, synthesized in cell bodies, must be efficiently delivered to axons to influence neuronal connectivity. Transcytosis is an atypical transport mode, where membrane proteins internalized from soma surfaces are anterogradely transported to axons. Here, we define the trafficking dynamics and the transport vesicles involved in transcytosis of TrkA neurotrophin receptors and demonstrate that transcytosis controls formation of presynaptic sites in sympathetic neurons. Live imaging and electron microscopy in compartmentalized cultures revealed that soma surface-derived TrkA receptors undergo dynamic movements in axons and are housed in endosomes and multi-vesicular bodies. Soma-surface labeled TrkA appear in nerve terminals, demonstrating transcytosis occurs in vivo. Notably, transcytosed TrkA receptors are enriched at presynaptic varicosities. Disruption of transcytosis impairs the number and morphology of presynaptic sites and decreases synaptic transmission. These findings provide mechanistic insight into an atypical mode of receptor trafficking and highlights its physiological relevance in sympathetic neuron connectivity.

cell biology↗

bioRxiv2025

Near real-time data on the human neutralizing antibody landscape to influenza virus to inform vaccine-strain selection in September 2025

The hemagglutinin of human influenza virus evolves rapidly to erode neutralizing antibody immunity. Twice per year, new vaccine strains are selected with the goal of providing maximum protection against the viruses that will be circulating when the vaccine is administered [~]8-12 months in the future. To help inform this selection, here we quantify how the antibodies in recently collected human sera neutralize viruses with hemagglutinins from contemporary influenza strains. Specifically, we use a high-throughput sequencing-based neutralization assay to measure how 188 human sera collected from Oct 2024 to April 2025 neutralize 140 viruses representative of the H3N2 and H1N1 strains circulating in humans as of the summer of 2025. This data set, which encompasses 26,148 neutralization titer measurements, provides a detailed portrait of the current human neutralizing antibody landscape to influenza A virus. The full data set and accompanying visualizations are available for use in vaccine development and viral forecasting.

microbiology↗