Science Journals

In presynaptic nerve terminals, the endocytic apparatus rapidly restores synaptic vesicles after neurotransmitter release. Many endocytic proteins localize to the periactive zone, a loosely defined area adjacent to active zones. A prevailing model posits that recruitment of these endocytic proteins to the periactive zone is activity-dependent. We show that periactive zone targeting of endocytic proteins is largely independent of active zone machinery and synaptic activity. At mouse hippocampal synapses and <i>Drosophila</i> neuromuscular junctions, pharmacological or genetic silencing resulted in unchanged or increased levels of endocytic proteins including Dynamin, Amphiphysin, Nervous Wreck, Endophilin A, Dap160/Intersectin, PIPK1γ, and AP-180. Similarly, disruption of active zone assembly via genetic ablation of active zone scaffolds at each synapse did not impair the localization of endocytic proteins. Overall, our work indicates that endocytic proteins are constitutively deployed to the periactive zone and supports the existence of independent assembly pathways for active zones and periactive zones.

Respiratory organs must balance their primary function of gas exchange with the constant threat of inhaled pathogens. In the <i>Drosophila</i> tracheal system, gas exchange occurs at the tracheal terminal cells (TTCs), the functional equivalents of mammalian alveoli. While bacterial infection triggers a robust innate immune response throughout the broader airway epithelium, we reveal that TTCs are uniquely exempt from this reaction. Mechanistically, TTCs lack expression of the membrane-associated peptidoglycan recognition receptor PGRP-LC. This absence protects these highly susceptible cells from immune deficiency (Imd) pathway activation and subsequent JNK-mediated cell death, establishing TTCs as a distinct, immune-privileged niche. Ectopic immune activation via targeted <i>PGRP-LCx</i> overexpression in TTCs caused a severe reduction in branching, cellular damage, and ultimately cell death, phenotypes that were fully rescued by the depletion of AP-1 or <i>foxo</i>. Because both structural plasticity (in response to nutritional cues and hypoxia) and innate immune responses strictly require the transcription factor FoxO, we demonstrate that potent immune signaling is fundamentally incompatible with dynamic TTC remodeling. Ultimately, the immune-privileged status of TTCs represents an essential evolutionary trade-off, restricting local inflammation to preserve <i>foxo</i>-dependent structural plasticity and vital respiratory function.

Li T, Yang L, Tu J, Hao Y, Zhu Z, Xiong Y, Gao Q, Zhou L, Xie G, Zhang D, Li X, Jin Y, Zhang Y, Zhao B, Li N, Wang X, Jia J-M. 2025. The myeloid cell-driven transdifferentiation of endothelial cells into pericytes promotes the restoration of BBB function and brain self-repair after stroke. eLife 14:RP105593. doi: 10.7554/eLife.105593. Published 16 July 2025 We have identified errors in the chart legend in Figure 9D of our published eLife article. One of the groups is incorrectly labelled. The order of the groups in the chart legend is incorrect and inconsistent with the other charts in Figure 9. How the correction was made: 1. Group designation error (incorrect group names): The experimental group (red) was incorrectly labelled “iECs”. The label has now been corrected to “iECs:Tgfbr2fl/fl”. 2. Incorrect placement of group positions: The control group “Tgfbr2fl/fl” was incorrectly placed at the bottom of the chart legend, we have corrected this to place this at the top. In turn the experimental group “iECs:Tgfbr2fl/fl” was incorrectly placed at the top, we have corrected this to place this group at the bottom. We have carefully rechecked the published eLife article. Importantly, these corrections do not affect the data presented in Figure 9, nor do they alter the results or conclusions of the study. All authors have reviewed and agreed to the changes. The corrected Figure 9 (updated for panel D) is shown here: The originally published Figure 9 is shown for reference: The article has been corrected accordingly. Author details © 2026, Li et al. This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited. - - 0 - citations Views, downloads and citations are aggregated across all versions of this paper published by eLife.

The mechanotransduction process relies on the interaction of mechanical and biochemical cues, transmitting cellular forces to intracellular organelles to activate biochemical pathways and elicit responses. This involves mechanoresponsive components like actin filaments, microtubules (MTs), and the lamin meshwork. Fluidic force microscopy (FluidFM), a force-controlled micropipette, allows for the manipulation of intact cells mechanically and chemically, providing a novel approach to study mechanotransmission in cells in situ. FluidFM combined with fluorescence lifetime imaging microscopy (FLIM) enables high-resolution mapping of intracellular tension dynamics. Here, we used cells with varying nuclear lamina compositions to explore the lamina’s role in initiating mechanoresponse to external cues. We found that A- and B-type lamins trigger nuclear mechanoresponse distinctly, with A-type lamins contributing to nuclear elasticity, whereas B-type lamins influence viscous response. Moreover, MTs underwent mechanical adaptation and assisted in releasing the tension in lamin A/C knockout (KO) cells, contrasting with healthy cells where MTs aid in preserving the tension locally rather than transferring it. This research provides insights into the dynamic mechanoresponse of cellular components and supports targeted therapies for mechanical stress-related diseases.

Cortical circuits produce time-varying patterns of population and single-neuron activity that play a fundamental role in perceptual and behavioral processes. However, the functional contributions of individual neuron activity to population dynamics and behavior remain unclear. Here, we addressed this issue focusing on the mouse gustatory cortex (GC) and using a taste mixture-based decision-making task, high-density electrophysiology, and computational modeling. GC population dynamics represented stimuli linearly during taste sampling, and choices categorically before decisions. Single neurons were classified by their linear and categorical activity patterns, revealing sub-populations encoding sensory, perceptual, and decisional variables. To test their functional role, we built a recurrent neural network model of GC. Model perturbations showed linear and categorical neurons were essential for driving normal population dynamics and behavioral performance, whereas many units with other activity patterns could be silenced without consequence. These results have implications that extend beyond GC and demonstrate the role of linear and categorical coding neurons in cortical dynamics and behavior during perceptual decision-making.

Value-based decision making is regulated by a delicate interplay of instrumental and Pavlovian controllers. Here, we assessed the role of catecholamines in this interplay. We investigated the effects of the catecholamine reuptake inhibitor methylphenidate (MPH) in 100 healthy subjects using a combined appetitive and aversive Pavlovian-to-instrumental transfer (PIT) paradigm, including approach and withdrawal actions. By administering the drug after learning, our design allowed us to establish that MPH can also bias action outside a learning context by directly modulating the interaction of Pavlovian cues with instrumental action. Previously we showed that the effect of MPH on bias varied across these individuals as a function of their working memory (WM) span capacity (Swart et al., 2017). Here, we show by assessing both approach and withdrawal actions that MPH enhanced not only the invigorating effect of appetitive cues on active approach but also the inhibitory effect of appetitive Pavlovian cues on active withdrawal and the invigorating effect of aversive cues on active withdrawal. Thus, in participants with high WM capacity, MPH boosted both approach and withdrawal PIT. Taken together, this pattern of effects is most consistent with the hypothesis that MPH modulates the <i>cognitive control of Pavlovian biasing</i> in a baseline-state-dependent manner, in line with the well-established inverted U-shaped relationship between catecholamine receptor stimulation in prefrontal cortex and cognitive control.

Widespread antibiotic usage has resulted in the rapid evolution of drug-resistant bacterial pathogens. Resolving how pathogens respond to antibiotics under different contexts is critical for understanding disease emergence. It remains unclear how interactions between hosts and antibiotics impact pathogen evolution. Here, we evolved <i>Staphylococcus aureus,</i> a major bacterial pathogen, varying exposure to host and antibiotics to tease apart the contributions of these selective pressures on pathogen adaptation. After 12 passages, <i>S. aureus</i> evolving in <i>Caenorhabditis elegans</i> nematodes exposed to a sub-minimum inhibitory antibiotic concentration became highly virulent, regardless of whether the ancestral pathogen was methicillin-resistant (MRSA) or methicillin-sensitive (MSSA). Host and antibiotic selected for reduced drug susceptibility in MSSA while increasing MRSA total growth outside hosts. We identified mutations in genes involved in regulatory networks linking virulence and metabolism, suggesting that rapid adaptation to infect hosts may have pleiotropic effects. Mutations that arose in these genes were also enriched in clinical isolates associated with systemic infections in humans. Despite evolving in similar environments, MRSA and MSSA populations—differing only in the presence of an intact accessory gene—proceeded on divergent evolutionary paths, with MSSA populations exhibiting more similarities across replicates. Our results underscore the importance of the host context as a driver of virulence and antibiotic resistance.

Human Papillomaviruses (HPVs) are the underlying cause of several types of cancer; albeit, they are mostly known for their association with cervical carcinoma. The virions reach their target cells through a break in the epithelial barrier. After binding to heparan sulfate (HS) of the extracellular matrix (ECM), they are recruited via actin-dependent mechanisms to the cell surface, where they co-internalize with the entry factor CD151. The in vivo occurring active recruitment from the ECM to the cell surface may be bypassed in cell culture, where virions reach the cell surface simply by passive diffusion. To specifically investigate these early events of the infection cascade, we use HaCaT keratinocytes as they produce a robust ECM enabling abundant virion binding to ECM components such as HS before transfer to cell surface receptors and infection. Employing microscopy, we focus on the basal membrane that for virions is difficult to access by diffusion. We block the active recruitment from ECM attachment sites to the cell body, release the blocking, and monitor the association of virions with CD151 or HS. We observe quick virion recruitment from the ECM to the cell body within 15 min. During recruitment, virions associate with the tetraspanin CD151 present at the cell border or at filopodia. These virions are decorated with HS, which they lose in the next few hours, presumably prior to endocytosis. Our observations reveal a rapid step in the HPV infection cascade: the transfer of HS-coated virions from the ECM to CD151. This step is too fast to account for the asynchronous uptake of HPVs, which is likely driven by glycan and capsid processing.

The phyla making up the major animal clade of Spiralia have been clear since the advent of molecular phylogenetics; the relationships between these spiralian phyla have not. The lack of consensus over the relationships between these important animal phyla might be a clue implying their emergence in an explosive radiation. Focussing on the five largest spiralian clades (Annelida, Brachiozoa, Mollusca, Nemertea, and Platyhelminthes) and using two phylogenomic datasets, we have applied site-bootstrapping and taxon-jackknifing to explore this example of taxonomic instability. Analyses of the 105 possible rooted trees relating them showed that interphylum branches are very short. Preference for rooting Spiralia on Platyhelminthes is enhanced by a long-branch artefact. Most analyses on the 15 unrooted trees showed a preference for the same topology but the support for this tree over other solutions was not significant. We conclude that the spiralian phyla emerged in rapid succession resulting in a difficult-to-resolve radiation. The deep history we infer for Spiralia has wide-ranging implications for our interpretation of Cambrian fossils and for the evolution of traits such as biomineralisation, segmentation, and larvae.

The Faroe Islands are home to descendants of a North Atlantic founder population with a unique history shaped by both migration and periods of relative isolation. Here, we investigate the genetic diversity, population structure, and demographic history of the islands by analyzing whole genome sequencing data from 40 participants in the Faroe Genome Project. This represents the first whole genome sequencing panel of this size from the Faroe Islands. We observed numerous putatively functional private alleles, including stop gain variants and high impact missense variants in the cohort. Faroese individuals had a higher proportion of their genomes contained in long runs of homozygosity than other European groups, including Finnish, suggesting a more recent or stronger bottleneck in the Faroese population. Signals of positive selection were identified at loci containing genes that play roles in vitamin D and dietary fat absorption and DNA repair, while increased diversity on lactase persistence haplotypes was observed. Fine-scale analysis of haplotype structure in present-day and ancient European genomes revealed genetic affinities with ancient Iron Age individuals from the North and West of Europe, providing evidence for potential contributions to the Faroese gene pool from Celtic and Viking populations as well as information about the temporal order in which these events happened. This study highlights the impact of evolutionary processes, such as ancient admixture, founder events, and positive selection, on the present-day genetic architecture of North Atlantic founder populations like the Faroe Islands.

Cancer progression involves extensive alterations in epigenetic and gene expression programs, but the accompanying changes in higher-order genome organization remain less well understood. Using high-resolution Micro-C mapping in the MCF10 cell model of breast cancer, we profiled chromatin compartments, topologically associated domains, and chromatin loops. We find large-scale compartmental shifts occur predominantly in early stages of cancer development, with more fine-scale structural changes in topologically associating domains and loops accumulating during the later transition to metastasis. Relating these chromatin features to gene expression and enhancer-associated histone marks revealed that many differentially expressed genes are physically connected to distal regulatory elements. While enhancer–promoter contact frequency and distal enhancer activity correlated with gene expression, strong changes in chromatin looping were relatively infrequent during progression, suggesting that alterations in chromatin contacts are not globally necessary, but may facilitate gene regulation at a subset of genes. These results elucidate the connection between gene regulation and genome remodeling in a cell-based cancer progression model.

The mammalian circadian clock is governed by a feedback loop in which the transcription activator CLOCK:BMAL1 induces expression of its inhibitors, PERs and CRYs, which form a complex with CK1δ, the main circadian kinase. However, the spatiotemporal dynamics of this feedback loop and the precise role of CK1δ remain incompletely understood. Using an inducible overexpression system, we show that nuclear availability of CK1δ is limited by both rapid nuclear degradation and active export of unassembled kinase, while cytoplasmic kinase is readily available for association with PERs. We demonstrate that CK1δ-mediated phosphorylation may disrupt PER2–CRY1 interaction, thereby resulting in cytoplasmic PER2 dimers containing substoichiometric amounts of CRY1. Analysis of endogenous PER2 localization in the context of an intact circadian clock reveals that PER2 accumulates in the cytoplasm late in the circadian cycle. Based on these findings, we propose that cytoplasmic accumulation of PER:CRY:CK1δ complexes contributes to the clearance of nuclear PER2, while the CK1δ-dependent release of CRY1 into the nucleus may sustain CLOCK:BMAL1 repression on DNA, supporting the transition from the early to the late repressive phase.

Ewing sarcoma is the second most common bone cancer in children and young adults. In 85% of patients, a translocation between chromosomes 11 and 22 results in a potent fusion oncoprotein, EWSR1::FLI1. EWSR1::FLI1 is the only genetic alteration in an otherwise unaltered genome of Ewing sarcoma tumors. The EWSR1 portion of the protein is an intrinsically disordered domain involved in transcriptional regulation by EWSR1::FLI1. The FLI portion of the fusion contains a DNA binding domain shown to bind core GGAA motifs and GGAA repeats. A small alpha-helix in the DNA binding domain of FLI1, DBD-α4 helix, is critical for the transcription function of EWSR1::FLI1. In this study, we aimed to understand the mechanism by which the DBD-α4 helix promotes transcription and therefore oncogenic transformation. We utilized a multi-omics approach to assess chromatin organization, active chromatin marks, genome binding, and gene expression in cells expressing EWSR1::FLI1 constructs with and without the DBD-α4 helix. Our studies revealed DBD-α4 helix is crucial for cooperative binding of EWSR1::FLI1 at GGAA microsatellites. This binding underlies many aspects of genome regulation by EWSR1::FLI1, such as formation of topologically associated domains (TADs), chromatin loops, enhancers, and productive transcription hubs.

The experience of pain, like other interoceptive processes, has recently been conceptualized in terms of predictive coding and free energy frameworks. In these views, the brain integrates sensory, proprioceptive, and interoceptive signals to generate probabilistic inferences about upcoming events, which shape both the state and the perception of our inner body. Here, we ask whether it is possible to induce pain expectations by providing false faster (vs. slower) acoustic cardiac feedback before administering electrical cutaneous shocks. We test whether these expectations will shape both the perception of pain and the body’s physiological state toward prior predictions. Results confirmed that faster cardiac feedback elicited pain expectations that affected both perceptual pain judgments and the body’s physiological response. Perceptual pain judgments were biased toward the expected level of pain, such that participants illusorily perceived identical noxious stimuli as more intense and unpleasant. Physiological changes mirrored the predicted level of pain, such that participants’ actual cardiac response in anticipation of pain stimuli showed a deceleration in heart rate, in line with the well-known orienting cardiac response in anticipation of threatening stimuli (Experiment 1). In a control experiment, such perceptual and cardiac modulations were dramatically reduced when the feedback reproduced an exteroceptive, instead of interoceptive, cardiac feedback (Experiment 2). These findings show that cardiac perception can be understood as interoceptive inference that modulates both our perception and the physiological state of the body, thereby actively generating the interoceptive and autonomic consequences that have been predicted.

Traumatic brain injury (TBI) often results in persistent learning and memory deficits, likely due to disrupted hippocampal circuitry underlying these processes. Precise temporal control of hippocampal neuronal activity is thought to be important for memory encoding and retrieval and is supported by oscillations that dynamically organize single-unit firing. Using high-density laminar electrophysiology, we found a loss of oscillatory power across CA1 lamina, with a profound, layer-specific reduction in theta-gamma phase-amplitude coupling in injured rats. Interneurons from injured animals were less strongly entrained to theta and gamma oscillations, but both interneurons and pyramidal cells from injured animals became more strongly entrained to theta during periods of high theta power. During quiet immobility, sharp-wave ripple amplitudes were lower in injured animals compared to shams. These results reveal physiological deficits across brain states that may contribute to TBI-associated learning and memory impairments and elucidate potential targets for future neuromodulation therapies.

Phytoplankton serve as a source of nutrients for bacteria in the marine environment. The interactions between algae and bacteria are known to include mutualism, commensalism, competition, or antagonism. This occurs in the microenvironment surrounding phytoplankton cells, the phycosphere, an interface rich in nutrients and organic molecules exuded by the cells. Here, based on <i>in situ</i> observations and on an <i>in vitro</i> interaction study, we report on a novel form of starvation-induced hunting that the cells of selected Vibrio species exert on dinoflagellates. The results showed that <i>Vibrio atlanticus</i> was capable of attacking and killing the dinoflagellate <i>Alexandrium pacificum</i> ACT03. Briefly, the observed mechanism of algal-killing consists of first, the ‘immobilization stage’ involving the secretion of algicidal metabolites that disrupt the flagella of the algae. In the ‘attack stage’, Vibrios simultaneously surround algal cells at high density for a brief period without invading them. Finally, the ‘killing stage’ in which the lysis and consumption of the dinoflagellates occur. By using a combination of biochemical, proteomic, molecular, and fluorescence microscopy approaches, we showed that this relationship is not related to the decomposition of algal organic matter, <i>Vibrio</i> quorum-sensing pathways, toxicity of the algae, or pathogenicity of the bacterium but is conditioned by nutrient stress, iron availability, and linked to the iron-vibrioferrin transport system of <i>V. atlanticus</i>. This is the first evidence of a new mechanism that could be involved in regulating <i>Alexandrium</i> spp. blooms and giving Vibrio a competitive advantage in obtaining nutrients from the environment. The interaction model we propose here suggests that Vibrio could play a role in regulating the proliferation of <i>Alexandrium</i> spp., giving it a competitive advantage in obtaining nutrients from the environment.

Touch plays a key role in our perception of our body and shapes our interactions with the world, from the objects we manipulate to the people we touch. While the tactile sensibility of the hand has been extensively characterized, much less is known about touch on other parts of the body. Despite the important role of the breast in lactation, as well as in affective and sexual touch, relatively little is known about its sensory properties. To fill this gap, we investigated the ability of women to locate touches on the breast and compared it to that of the hand and back, body regions that span the range of tactile discriminative capabilities. First, we found that the tactile precision of the breast was even lower than that of the back, heretofore the paragon of poor precision. Second, precision was lower for breasts that had undergone greater expansion, consistent with the hypothesis that innervation capacity does not scale with body size. Third, touches to different regions of the nipple were largely indistinguishable, suggesting sparse innervation density. Fourth, localization errors were systematically biased toward the nipple.

Chromosomes must efficiently and properly interact with the mitotic spindle during prometaphase for correct segregation in anaphase. Chromosomes at the nuclear periphery or behind the spindle poles interact less efficiently with the mitotic spindle, increasing the risk of missegregation. The mechanisms that mitigate such risks in unperturbed cells are unknown. An actomyosin network (PANEM) forms around the nucleus during prophase. While the myosin-II-dependent PANEM contraction immediately after nuclear envelope breakdown (NEBD) facilitates chromosome interaction with the mitotic spindle, the mechanism by which it does so remains unclear. Here, using human cell lines, we show that immediately after NEBD, PANEM contraction directly pushes chromosomes at the nuclear periphery or behind spindle poles toward the center of cells. Detailed tracking of kinetochore movements following light-induced activation of a myosin II inhibitor reveals that this inward movement of chromosomes facilitates kinetochores’ initial interaction with spindle microtubules. It also promotes the onset of kinetochores’ congression toward the spindle mid-plane, but not congression itself once it starts. Thus, PANEM contraction ensures high-fidelity chromosome segregation by relocating chromosomes from unfavorable locations. Since some chromosomally unstable cancer cells fail to establish PANEM during early mitosis, the absence of PANEM may contribute to numerical chromosomal instability in these cells.

Size is a fundamental property of cells that influences many aspects of their physiology. This is because cell size sets the scale for all subcellular components and drives changes in the composition of the proteome. Given that large and small cells differ in their biochemical composition, we hypothesized that they should also differ in how they respond to signals and make decisions. Here, we investigated how cell size affects the susceptibility of human cells to cell death. We found that large cells are more resistant to ferroptosis caused by system x_c^- inhibition. Ferroptosis is a type of cell death characterized by the iron-dependent accumulation of toxic lipid peroxides. This process is opposed by cysteine-dependent lipid peroxide detoxification mechanisms. We found that larger cells exhibit higher concentrations of the cysteine-containing metabolite glutathione and lower concentrations of membrane lipid peroxides. Mechanistically, this can be explained by the fact that larger cells had lower concentrations of an enzyme that enriches cellular membranes with peroxidation-prone polyunsaturated fatty acids, ACSL4, and increased concentrations of the glutathione-producing enzymes glutamate-cysteine ligase and glutathione synthetase, the iron-chelating protein ferritin, and the lysosomal protease cathepsin B, which can catabolize cysteine-rich extracellular proteins to produce additional cystine for fueling the synthesis of glutathione. Taken together, our results highlight the significant impact of cell size on cellular function and survival, revealing a size-dependent vulnerability to ferroptosis that could influence therapeutic strategies based on this cell death pathway.

Snake venoms contain diverse mixtures of toxins that evolved to incapacitate prey, but in humans, they cause extensive pathology following snakebite envenomation. In viper venom, some of the most potent toxins are the haemorrhagic and coagulopathic snake venom metalloproteinases (SVMPs). Because venoms contain an SVMP cocktail and due to their cytotoxicity, SVMP characterisations have been hampered by the lack of purified enzymes. By incorporating their prodomain, which blocks the active SVMP site, we overcame their cytotoxicity and enabled recombinant production of zymogens from all three structurally variable SVMP classes (PI, PII, and PIII) using our baculovirus/insect cell expression system. Zymogens were auto-activated by incubation with Zn²⁺ ions, resulting in prodomain cleavage, PII disintegrin cleavage and PIII prodomain proteolysis. Auto-activated SVMPs were characterised using protein substrate degradation, platelet aggregation and blood coagulation assays, benchmarked to native venom-purified SVMP. Our recombinant zymogen production protocol is generically applicable for the expression of SVMPs, unlocking biomedical use in haematology and discovery of novel snakebite therapeutics.

Altered sensory perception is a hallmark of autism and shapes how individuals engage with their environment, with tactile perception playing a critical role in daily functioning and for social interactions. While sensory alterations are thought to contribute to cognitive differences in autism, the impact of cognition on sensory perception remains unclear. Here, we investigated how cognitive processes modulate tactile perception in the <i>Fmr1-</i>KO genetic mouse model of autism through a translational perceptual decision-making task. Our results revealed salience-dependent cognitive alterations that influenced sensory performance. During training, <i>Fmr1</i>^-/y male mice distinguishing between a high- and a low-salience stimulus exhibited an increased choice consistency bias in low-salience trials. When tested across a continuum of intermediate stimulus intensities, these mice demonstrated enhanced tactile discrimination of low-salience stimuli but reduced discrimination facilitation for stimuli crossing category boundaries. These effects were accompanied by diminished integration of sensory history and were dissociable from the attention deficits that emerged under high cognitive load. Together, our findings reveal that tactile perceptual alterations reflect context-dependent weighting and integration of sensory information during decision-making rather than uniform sensory deficits or enhancements, supporting a shift beyond traditional sensory–cognitive dichotomies.

Tyrosine kinase 2 (TYK2) is a genetically defined target for autoimmune disease, with first-generation inhibitors showing clinical success in some but not all associated indications. A deeper understanding of TYK2 structure-function relationships, protein-ligand interactions, and the impact of human variants could inform next-generation therapeutics. Here, we applied deep mutational scanning (DMS) to assess &gt;23,000 amino acid substitutions across two TYK2 functions: interferon alpha (IFN-α) signaling and protein abundance. This enabled high-resolution structure-function mapping and the identification of novel allosteric sites. By coupling DMS with inhibitor treatment, we uncovered variants that modulate compound potency. We also show that human variants – both common and rare – that are protective against autoimmune phenotypes reduce TYK2 protein abundance. Together, these findings demonstrate that DMS can prospectively reveal novel druggable sites, clarify structure-activity relationships (SAR), and highlight TYK2 degradation as a potential therapeutic strategy in autoimmunity.

Stimulating brain areas connected to the hippocampus may improve memory function in humans.

Excessive alcohol consumption poses significant health risks and is closely associated with oxidative damage. The KEAP1-NRF2-ARE signaling pathway serves as the primary antioxidant system. However, current small molecule inhibitors are all covalently bound to KEAP1, meaning that once bound, they are not easily dissociated, while continuous inhibition of KEAP1 exhibits severe side effects. In this study, BLI, CETSA, Pull-down, Co-IP, and HDX-MS assay analysis were conducted to detect the KEAP1 binding behavior of natural product, capsaicin (CAP), both in vitro and in cells. The ethanol-induced acute gastric mucosal damage rat model was also established to evaluate the therapeutic effect of CAP. Our findings demonstrated that CAP mitigated mitochondrial damage, facilitated the nuclear translocation of NRF2, leading to the up-regulation of downstream antioxidant response elements, HMOX1, TXN, GSS, and NQO1 in GES-1 cells. Furthermore, CAP directly bind to KEAP1 and inhibit the interaction between KEAP1 and NRF2. In the KEAP1-knockout 293T cells, CAP failed to activate NRF2 expression. We identified that CAP non-covalently bound to the Kelch domain and allosterically regulated three specific regions of KEAP1: L342-L355, D394-G423, and N482-N495. To improve drug solubility and delivery efficiency, we developed IR-Dye800 modified albumin-coated CAP nanoparticles. The nanoparticles significantly reduced the gastric mucosal inflammation and activated NRF2 downstream genes in vivo. Our hypothesis was further verified our hypothesis in Nrf2-knockout mice. This study provides new insights that CAP is a safe and novel NRF2 agonist by allosterically regulating KEAP1, which may contribute to the development of lead drugs for oxidative stress-related illness, e.g., aging, cancer, neurodegenerative, and cardiovascular diseases.

Perception relies on the neural representation of sensory stimuli. Primary sensory cortical representations have been extensively studied, but how sensory information propagates to memory-related multisensory areas has not been well described. We studied this question in the olfactory cortico-hippocampal pathway in mice. We recorded single units in the anterior olfactory nucleus (AON), the anterior piriform cortex (aPCx), the lateral entorhinal cortex (LEC), the hippocampal CA1 subfield, and the subiculum (SUB) while animals performed a non-associative learning paradigm involving novel and familiar stimuli. In the AON, neurons were broadly tuned to different chemicals, and their responses were strongly modulated by experience. From the AON to hippocampal structures, the selectivity of neurons for specific odorants increased, concurrent with the development of population-level odor representations, which became independent of novelty and familiarity. While both stimulus identity and experience were thus reflected in all regions, their neural representations progressively separated. Our findings provide a potential mechanism for how sensory representations are transformed to support stimulus identification and implicit memories.