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Shao, J.

Publications and source records attributed to Shao, J..

At least 37 records · Page 2Linked to original sources

Sidero-Mining: Systematic Extraction of Siderophore Biosynthetic Information Using Large Language Models

Siderophores are central mediators of microbial iron acquisition, competition, and ecological adaptation, yet their biosynthetic diversity remains difficult to resolve across species because existing sequence-based BGC comparison is strongly constrained by phylogenetic background. Here we combine large-language-model-assisted literature mining, functional-space comparison, and genome-scale analysis to resolve the global organization of siderophore biosynthesis across bacteria. We first built SideroBank, a manually curated cross-species benchmark of siderophore biosynthetic gene clusters (BGCs), and used it to show that many identical products recur across distant taxa whereas the corresponding BGCs often fail to cluster in sequence space. We then developed BGC Block Aligner, which compares BGCs as ordered systems of functionally meaningful blocks and thereby converts comparison from sequence space to functional space. Applied to 97,432 bacterial genomes, this framework produced the Siderophore Atlas, revealing that siderophore synthesis is a remarkably pervasive trait encoded by over 60% of the analyzed genomes, with certain clusters being the most widely disseminated secondary metabolites across the bacterial domain. This global landscape suggests that the adoption of specific biosynthetic strategies is predominantly driven by ecological lifestyle rather than strict phylogenetic relatedness. Furthermore, a stark macro-evolutionary dichotomy was observed between the continuous structural diversification of NRPS pathways and the standardized, HGT-driven dissemination of NIS systems, linking functional-space genomics to the global ecology and evolution of siderophore biosynthesis..

bioinformatics↗

Leopard Cats Occupied Human Settlements in China for 3,500 years before the Arrival of Domestic cats in 600-900 CE around the Tang Dynasty

The earliest cats in human settlements in China were not domestic cats (Felis catus), but native leopard cats (Prionailurus bengalensis). To trace when and how domestic cats arrived in East Asia, we analyzed 22 feline bones from 14 sites across China spanning 5,000 years. Nuclear and mitochondrial genomes revealed that leopard cats began occupying anthropogenic scenes around 5,400 years ago and last appeared in 150 CE. Following several centuries gap of archeological feline remains, the first known domestic cat (706-883 CE) in China was identified in Shaanxi during the Tang Dynasty. Genomic analysis suggested a white or partially white coat and a link to a contemporaneous domestic cat from Kazakhstan, indicating a likely dispersal route via the Silk Road. The two felids once independently occupied ancient anthropogenic environments in China but followed divergent paths and reached different destinations in human-animal interactions.

evolutionary biology↗

Systematic Identification of Microtubule Inner Proteins Reveals JPT2 as a Key Regulator of Lumen Microenvironment and Drug Sensitivity

Microtubules are primarily studied for the interactions of proteins that bind to their outer surfaces and ends, while the regulatory mechanisms within the microtubule lumen, particularly in singlet microtubules critical for essential cellular processes, remain largely unexplored. Our study provides the first systematic identification of key regulatory proteins within the single microtubule lumen. Using proximity-dependent biotin identification (Bio-ID) coupled with mass spectrometry, we identified candidate microtubule inner proteins (MIPs), including Jupiter microtubule-associated homolog 2 (JPT2). JPT2 binds directly to microtubules and specifically localizes within the lumen, where it modulates the luminal environment by inhibiting acetylase MEC17 and independently affects the binding and efficacy of Paclitaxel. Furthermore, our screening identified additional MIPs that influence cellular sensitivity to Paclitaxel, indicating a link between luminal regulation and drug responsiveness. These discoveries reveal JPT2s critical role in singlet microtubule regulation and suggest new therapeutic targets for enhancing cancer drug sensitivity.

cell biology↗

An annotated biobank of triple negative breast cancer patient-derived xenografts featuring treatment-naive and longitudinal samples throughout neoadjuvant chemotherapy

Triple negative breast cancer (TNBC) that fails to respond to neoadjuvant chemotherapy (NACT) can be lethal. Developing effective strategies to eradicate chemoresistant disease requires experimental models that recapitulate the heterogeneity characteristic of TNBC. To that end, we established a biobank of 92 orthotopic patient-derived xenograft (PDX) models of TNBC from the tumors of 75 patients enrolled in the ARTEMIS clinical trial (NCT02276443) at MD Anderson Cancer Center, including 12 longitudinal sets generated from serial patient biopsies collected throughout NACT and from metastatic disease. Models were established from both chemosensitive and chemoresistant tumors, and nearly 30% of PDX models were capable of lung metastasis. Comprehensive molecular profiling demonstrated conservation of genomes and transcriptomes between patient and corresponding PDX tumors, with representation of all major transcriptional subtypes. Transcriptional changes observed in the longitudinal PDX models highlight dysregulation in pathways associated with DNA integrity, extracellular matrix interactions, the ubiquitin-proteasome system, epigenetics, and inflammatory signaling. These alterations reveal a complex network of adaptations associated with chemoresistance. This PDX biobank provides a valuable resource for tackling the most pressing issues facing the clinical management of TNBC, namely chemoresistance and metastasis.

cancer biology↗

Blocking SHP2 benefits FGFR2 inhibitor and overcomes its resistance in FGFR2-amplified gastric cancer

Fibroblast growth factor receptor 2 (FGFR2) is an important member of receptor tyrosine kinase (RTK) family. FGFR2 amplification occurs at a high frequency in gastric cancer (GC) and has been proven to be closely associated with poor prognosis and insensitivity to chemotherapy or immunotherapy. Current FGFR2-targeted therapies have limited efficacy. Hence, how to enhance efficacy and reverse resistance are urgent problems clinically. Src homology region 2-containing protein tyrosine phosphatase 2 (SHP2) serves as the shared downstream mediator of all RTKs and a prominence immunosuppressive molecule. In this study, we identified FGFR2 amplification in 6.2% (10/161) of GC samples in our center. Then we showed that dual blocking SHP2 and FGFR2 enhanced the effects of FGFR2 inhibitor (FGFR2i) in FGFR2-amplified GC both in vitro and in vivo via suppressing RAS/ERK and PI3K/AKT pathways. We further showed that it overcame FGFR2i resistance by reversing the feedback activation mediated by other RTKs and continuously suppressing FGFR2-initiated downstream pathways. Notably, SHP2 blockade could suppress PD-1 expression and promoted IFN-{gamma} secretion of CD8+ T cells, enhancing the cytotoxic functions of T cells in tumor immune microenvironment. Overall, our findings suggest that dual blocking SHP2 and FGFR2 is a compelling rationale with both targeted treatment and immune regulation for FGFR2-amplified GC. Impact statementDual blocking SHP2 and FGFR2 can not only promote the targeted tumor-killing effects and overcome FGFR2 inhibitor resistance caused by feedback activation, but also activate T cell-mediated anti-tumor immunity by inhibiting PD-1 pathway in FGFR2-amplified GC. Funding informationThis work was funded by Grants from National Natural Science Foundation of China (82403862, 82403835), Jiangsu Provincial Natural Science Foundation Youth Project (BK20230151, BK20240247), Jiangsu Provincial Major Science and Technology Program (BG2024026), the Wu Jieping Medical Foundation Special Fund for Targeted Cancer Therapy (Youth Research Project) (320.6750.2023-11-30), Jiangsu Provincial Youth Science and Technology Talent Support Project (JSTJ-2025-715) and General Project of Nanjing Health Science and Technology Development Program (YKK24084).

cancer biology↗

Loss of neuropeptidergic regulation of cholinergic transmission induces CaV1-mediated homeostatic compensation in muscle cells

Chemical synaptic transmission at the neuromuscular junction (NMJ) is regulated by electrical activity of the motor circuit, but may also be affected by neuromodulation. Here, we assess the role of neuropeptide signaling in the plasticity of NMJ function in Caenorhabditis elegans. We show that the CAPS (Ca2+-dependent activator protein for secretion) ortholog UNC-31, which regulates the exocytosis of dense core vesicles (DCVs), affects both pre- and post-synaptic functional properties, as well as NMJ-mediated locomotion. Despite reduced evoked acetylcholine transmission, the loss of unc-31 results in a more vigorous response to presynaptic stimulation, i.e., enhanced muscle contraction and Ca2+ transients. Based on expression profiles, we identified neuropeptides involved in both cholinergic (FLP-6, NLP-9, NLP-21 and NLP-38) and GABAergic motor neurons (FLP-15, NLP-15), that mediate normal transmission at the NMJ. In the absence of these peptides, neurons fail to upregulate their transmitter output in response to increased cAMP signaling. We also identified proprotein convertases encoded by aex-5/kpc-3 and egl-3/kpc-2 that act synergistically to generate these neuropeptides. We propose that postsynaptic homeostatic scaling, mediated by increased muscle excitability, could compensate for the reduced cholinergic transmission in mutants affected for neuropeptide signaling, thus maintaining net synaptic strength. We show that in the absence of UNC-31 muscle excitability is modulated by upregulating the expression of the muscular L-type voltage gated Ca2+ channel EGL-19 (CaV1). Collectively, our results unveil a role for neuropeptidergic regulation in synaptic plasticity, linking changes in presynaptic transmission to compensatory changes in muscle excitability.

neuroscience↗

Centimeter-scale, physiologically relevant intestinal organoids generated entirely from pluripotent stem cells

Over the past decade, intestinal organoids have shown great promise as a platform to study the development of intestine, elucidate the pathogenesis of diseases such as inflammatory bowel disease (IBD), and model physiological features of intestinal tissue for high-throughput drug screening. However, intestinal organoids derived from adult epithelial stem cells lack cellular diversity, especially those resides in the lamina propria. Intestinal organoids derived from embryonic stem (ES) cells or induced-pluripotent stem cells (iPSCs) has greater cellular diversity, but are still limited in size and physiological features such as peristalsis. In this study, we generated centimeter-scale, full-thickness, and physiologically relevant intestinal organoids in suspension culture without usage of Matrigel. Using a series of optimized culture media, multiple lineages of cells were differentiated from iPSCs and spontaneously assembled to achieve the intestinal architecture. These bubble-like organoids have a thickness of 500 microns, exhibit a mature vasculature network, and have smooth muscle-like cells to conduct regular peristalsis. In addition, adipocyte-like cells and granulocyte-like cells are also observed in these organoids, which are important in immune homeostasis. Lastly, these organoids show mature crypt structures, response to lipopolysaccharides (LPS), and increases luminal influx upon forskolin treatment, suggesting the organoids have intact epithelial integrity. Thus, this study provides a highly reproducible approach to produce large and physiologically relevant intestinal organoids that are suitable for different biomedical applications.

cell biology↗

A scene with an invisible wall - navigational experience shapes visual scene representation

Human navigation heavily relies on visual information. Although many previous studies have investigated how navigational information is inferred from visual features of scenes, little is understood about the impact of navigational experience on visual scene representation. In this study, we examined how navigational experience influences both the behavioral and neural responses to a visual scene. During training, participants navigated in the virtual reality (VR) environments which we manipulated navigational experience while holding the visual properties of scenes constant. Half of the environments allowed free navigation (navigable), while the other half featured an invisible wall preventing the participants to continue forward even though the scene was visually navigable (non-navigable). During testing, participants viewed scene images from the VR environment while completing either a behavioral perceptual identification task (Experiment1) or an fMRI scan (Experiment2). Behaviorally, we found that participants judged a scene pair to be significantly more visually different if their prior navigational experience varied, even after accounting for visual similarities between the scene pairs. Neurally, multi-voxel pattern of the parahippocampal place area (PPA) distinguished visual scenes based on prior navigational experience alone. These results suggest that the human visual scene cortex represents information about navigability obtained through prior experience, beyond those computable from the visual properties of the scene. Taken together, these results suggest that scene representation is modulated by prior navigational experience to help us construct a functionally meaningful visual environment.

neuroscience↗

MICOS Complex Loss Governs Age-Associated Murine Mitochondrial Architecture and Metabolism in the Liver, While Sam50 Dictates Diet Changes

Background & AimsAging is associated with a significant decline in mitochondrial function in the liver, leading to an increased risk of liver disease. This study examines age-related changes in the mitochondrial structure of human and murine livers using a combination of Serial Block-Face Scanning Electron Microscopy (SBF-SEM) and mass spectrometry approaches. MethodsThis study integrates mitochondrial structure analysis in a murine model with an analysis of liver architecture, lipogenesis, and genetically regulated gene expression in human cohorts. We explored the Mitochondrial Contact Site and Cristae Organizing System (MICOS) complex using SBF-SEM, three-dimensional reconstruction with Amira software, and mass spectrometry techniques. ResultsAging leads to a reduction in mitochondrial size and complexity, resulting in changes in the metabolomic and lipidomic profiles of murine liver cells that are comparable to those observed in aged human samples. We find that genetically modeled expression of MICOS complex genes OPA1 and CHCHD3 is associated with chronic liver disease phenotypes within a large biobank population. Furthermore, we observed dysregulated mitochondrial calcium handling and increased oxidative stress due to the disruption of the MICOS complex. ConclusionOur study highlights the age-associated decline in mitochondrial complexity and metabolic regulation within the aging murine liver and the human population. We have identified that these changes are partially attributable to the age-related loss of the MICOS complex. Impact and implicationsThis study offers new insights into the changes to mitochondrial ultrastructure that occur during aging. Using SBF-SEM, the quantification of young and aged murine mitochondrial structure was performed, which had previously been an underexplored avenue for measuring mitochondrial changes. The discovery of mitochondrial ultrastructural changes, in conjunction with measurements of age-associated metabolic alterations and gene association data, provides a model for how changes in MICOS expression may modulate age-related impairment of hepatic mitochondria. These results provide a new model by which changes in MICOS protein expression may both cause and be a potential therapeutic target for age-related impairment in hepatic function. HighlightsDecreased modeled expression of CHCHD3 in individuals of European genetic ancestry is linked to liver transplant and cirrhosis, while decreased modeled expression of OPA1 in individuals of African genetic ancestry is associated with chronic liver disease and cirrhosis. Aging alters liver lipid accumulation, MICOS mRNA levels, and disease markers. Aging reduces the volume and complexity of murine liver ultrastructure. Aging and diet significantly alter the MICOS complex in mice. Knockdown of Mic60 and Chchd6 lowers Ca2+ uptake, retention, and induces oxidative stress in HepG2 cells. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=139 SRC="FIGDIR/small/599846v3_ufig1.gif" ALT="Figure 1000"> View larger version (47K): org.highwire.dtl.DTLVardef@1cdd61corg.highwire.dtl.DTLVardef@a3fb74org.highwire.dtl.DTLVardef@1d1ad36org.highwire.dtl.DTLVardef@c2e55f_HPS_FORMAT_FIGEXP M_FIG C_FIG Liver aging causes metabolic, lipidomic, and mitochondrial structural alterations, reflecting age-dependent losses in the MICOS complex. Key components of the MICOS complex (MIC60, CHCHD3 and CHCHD6) are illustrated.

physiology↗

The MICOS Complex Regulates Mitochondrial Structure and Oxidative Stress During Age-Dependent Structural Deficits in the Kidney

Due to aging, the efficiency of kidney function begins to decrease. Dysfunction in mitochondria and their cristae is a hallmark of aging. Therefore, age-related decline in kidney function could be attributed to changes in mitochondrial ultrastructure, increased reactive oxygen species, and alterations in metabolism and lipid composition. We sought to understand how mitochondrial ultrastructure is altered over time in tubular kidney cells. A serial block facing-scanning electron microscope and manual segmentation using the Amira software were employed to visualize murine kidney samples during the aging process at 3 months (young) and 2 years (old). We found that 2-year mitochondria are more fragmented with many uniquely shaped mitochondria observed across aging, concomitant with shifts in ROS, metabolomics, and lipid homeostasis. Furthermore, we demonstrate that the mitochondrial contact site and cristae organizing system (MICOS) complex is impaired in the kidney during aging. Disruption of the MICOS complex resulted in altered mitochondrial metabolic function and increased ROS levels. We found significant, detrimental structural changes in the mitochondria of aged kidney tubules, suggesting a potential mechanism underlying the increased frequency of kidney disease with aging. We hypothesize that disruption of the MICOS complex exacerbates mitochondrial dysfunction, creating a vicious cycle of mitochondrial degradation and oxidative stress, which impacts kidney health. Impact and ImplicationsDue to aging, the efficiency of kidney function begins to decrease, and the risk of kidney diseases may increase; however, the specific regulators of mitochondrial age-related changes are poorly understood. This study demonstrates that the MICOS complex may be a target for mitigating age-related mitochondrial changes. The MICOS complex is associated with oxidative stress and calcium dysregulation, which also arise in many kidney pathologies. HighlightsO_LIAging alters the MICOS mRNA levels and disease markers. C_LIO_LIAging reduces cristae architecture, mitochondrial volume and complexity in murine kidney ultrastructure C_LIO_LIReducing MIC60 and CHCHD6 lowers Ca2+ uptake and retention and induces oxidative stress in HEK cells. C_LIO_LIMetabolomic Profiling revealed that NAD+ and amino acid metabolism were altered in aged kidneys. C_LIO_LIMICOS deficiency alters the reduced basal, ATP-linked, maximal capacity and spare capacity. C_LIO_LIDecreased modeled expression of CHCHD6 in individuals of European genetic ancestry is linked to chronic kidney disease, whereas decreased modeled expression of OPA1 in individuals of African genetic ancestry is associated with chronic kidney disease. C_LI Graphical AbstractKidney aging causes a decline in the MICOS complex, concomitant with metabolic, lipidomic, and mitochondrial structural alterations. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/598108v3_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@1a868f0org.highwire.dtl.DTLVardef@1817bfborg.highwire.dtl.DTLVardef@1f2a1a3org.highwire.dtl.DTLVardef@520692_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

A functional parcellation of the whole brain in individuals with autism spectrum disorder reveals atypical patterns of network organization

BACKGROUNDResearchers studying autism spectrum disorder (ASD) lack a comprehensive map of the functional network topography in the ASD brain. We used high-quality resting state functional MRI (rs-fMRI) connectivity data and a robust parcellation routine to provide a whole-brain map of functional networks in a group of seventy individuals with ASD and a group of seventy typically developing (TD) individuals. METHODSThe rs-fMRI data were collected using an imaging sequence optimized to achieve high temporal signal-to-noise ratio (tSNR) across the whole-brain. We identified functional networks using a parcellation routine that intrinsically incorporates stability and replicability of the networks by keeping only network distinctions that agree across halves of the data over multiple random iterations in each group. The groups were tightly matched on tSNR, in-scanner motion, age, and IQ. RESULTSWe compared the maps from each group and found that functional networks in the ASD group are atypical in three seemingly related ways: 1) whole-brain connectivity patterns are less stable across voxels within multiple functional networks, 2) the cerebellum, subcortex, and hippocampus show weaker differentiation of functional subnetworks, and 3) subcortical structures and the hippocampus are atypically integrated with the neocortex. CONCLUSIONSThese results were statistically robust and suggest that patterns of network connectivity between the neocortex and the cerebellum, subcortical structures, and hippocampus are atypical in ASD individuals.

neuroscience↗

Siderophore Piracy Promotes Dynamical Coexistence in Microbial Community

Niche construction drives ecological dynamics, yet the tragedy of the commons predicts that non-contributing cheaters will undermine cooperation. Here, we studied microbial iron competition by combining dynamic modeling with benefit flow graphs, demonstrating that moderate cheating is not merely tolerated but essential for diversity. In small communities, mutual exploitation forms closed loops enabling steady or dynamic coexistence. In larger communities, we uncovered a paradox: increasing cheating breadth promotes community-level extinction, yet fosters higher biodiversity in surviving communities. We resolve this paradox by mapping ecological dynamics onto the topology of the "Maximal Benefit Transfer Graph", which predicts community fate through its core structure. Broad cheating eliminates the self-loop core that drives competitive exclusion, but increases "terminator" sinks that cause collapse. However, when communities avoid these sinks, cheating aggregates the network and generates cyclic loops to enable coexistence. Thus, structured exploitation acts not as destabilizing vulnerability but as necessary architecture for biodiversity. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/568182v3_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@143f144org.highwire.dtl.DTLVardef@194c2adorg.highwire.dtl.DTLVardef@1792d4aorg.highwire.dtl.DTLVardef@8c96a7_HPS_FORMAT_FIGEXP M_FIG C_FIG How does cheating affect microbial biodiversity? By mapping the strongest benefit flows between species, we discovered a topological rule for survival. While too much cheating creates dead-ends that crash the system, moderate cheating connects species into self-sustaining loops. These "exploitation cycles" act as a scaffold, supporting high diversity and complex population.

systems biology↗

Long noncoding RNA Hottip maintained skeletal homeostasis via suppressing the enhancer of zeste homolog 2 (Ezh2)/histone methylation regulatory axis

Recent evidence suggests that long noncoding RNAs (lncRNAs) play a crucial role in regulating bone remodeling and skeletal homeostasis by coordinating the development of osteoblasts and osteoclasts. Several lncRNAs have been identified to participate in bone formation and resorption processes. Among them, the well-known oncogenic lncRNA, Hottip, has been reported to be involved in osteogenesis regulation. However, the specific function and underlying mechanisms remain poorly understood. In this study, we investigated the role of lncRNA Hottip in bone remodeling and skeletal homeostasis. Hottip knockout mice exhibited disrupted bone metabolism, abnormal bone tissue, and compromised bone quality, resulting in delayed fracture healing. In vitro experiments demonstrated that Hottip knockdown inhibited osteoblast differentiation while promoting osteoclast differentiation, with the opposite effect observed upon Hottip overexpression. Mechanistically, Hottip physically interacted with EZH2, leading to its degradation and facilitating the transcription of osteogenic genes by suppressing H3K9me3 and H3K27me3. In vivo experiments further validated the potential of Hottip overexpression to promote bone regeneration and accelerate fracture healing. In conclusion, our study reveals Hottip as a critical regulator in the differentiation of osteoblasts and osteoclasts, crucial for maintaining skeletal homeostasis. This lncRNA shows potential as a promising therapeutic target for bone regeneration.

cell biology↗

From sequence to ecology: siderophore-receptor coevolution algorithm predicts bacterial interactions in complex communities

Predicting bacterial social interactions from genome sequences is notoriously difficult. Here, we developed bioinformatic tools to predict whether secreted iron-scavenging siderophores stimulate or inhibit the growth of community members. Siderophores are chemically diverse and can be stimulatory or inhibitory depending on whether bacteria possess or lack corresponding uptake receptors. We focused on 1928 representative Pseudomonas genomes and developed a co-evolution algorithm to match all encoded siderophore synthetases to corresponding receptor gene groups with >90% accuracy based on experimental validation. We derived community-level iron interaction networks to show that selection for siderophore-mediated interactions differs across habitats and lifestyles. Specifically, dense networks of siderophore sharing and competition were observed among environmental (soil/water/plant) strains and non-pathogenic species, while only fragmented networks occurred among human-derived strains and pathogenic species. Altogether, our sequence-to-ecology approach empowers the analyses of social interactions among thousands of bacterial strains and uncovers ways for targeted intervention to microbial communities. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=87 SRC="FIGDIR/small/565711v3_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@60d907org.highwire.dtl.DTLVardef@48756eorg.highwire.dtl.DTLVardef@115aac1org.highwire.dtl.DTLVardef@17d76e5_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

From sequence to molecules: Feature sequence-based genome mining uncovers the hidden diversity of bacterial siderophore pathways

Microbial secondary metabolites are a rich source for pharmaceutical discoveries and play crucial ecological functions. While tools exist to identify secondary metabolite clusters in genomes, precise sequence-to-function mapping remains challenging because neither function nor substrate specificity of biosynthesis enzymes can accurately be predicted. Here we developed a knowledge-guided bioinformatic pipeline to solve these issues. We analyzed 1928 genomes of Pseudomonas bacteria and focused on iron-scavenging pyoverdines as model metabolites. Our pipeline predicted 188 chemically different pyoverdines with nearly 100% structural accuracy and the presence of 94 distinct receptor groups required for the uptake of iron-loaded pyoverdines. Our pipeline unveils an enormous yet overlooked diversity of siderophores (151 new structures) and receptors (91 new groups). Our approach, combining feature sequence with phylogenetic approaches, is extendable to other metabolites and microbial genera, and thus emerges as powerful tool to reconstruct bacterial secondary metabolism pathways based on sequence data. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/564663v5_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@1dedad4org.highwire.dtl.DTLVardef@1f0a39eorg.highwire.dtl.DTLVardef@185e345org.highwire.dtl.DTLVardef@10beec6_HPS_FORMAT_FIGEXP M_FIG C_FIG

genomics↗

SIDERITE: Unveiling Hidden Siderophore Diversity in the Chemical Space Through Digital Exploration

Siderophores, a highly diverse family of secondary metabolites, play a crucial role in facilitating the acquisition of the essential iron. However, the current discovery of siderophore relies largely on manual approaches. In this work, we introduced SIDERTE, a digitized siderophore information database containing 872 siderophore records with 649 unique structures. Leveraging this digitalized dataset, we gained a systematic overview of siderophores by their clustering patterns in the chemical space. Building upon this, we developed a functional group-based method for predicting new iron-binding molecules. Applying this method to 4,314 natural product molecules from TargetMols Natural Product Library for high throughput screening, we experimentally confirmed that 40 out of the 48 molecules predicted as siderophore candidates possessed iron-binding abilities. Expanding our approach to the COCONUT natural product database, we predicted a staggering 3,199 siderophore candidates, showcasing remarkable structure diversity that are largely unexplored. Our study provides a valuable resource for accelerating the discovery of novel iron-binding molecules and advancing our understanding towards siderophores.

biochemistry↗

Molecular cartography uncovers evolutionary and microenvironmental dynamics in sporadic colorectal tumors

Colorectal cancer exhibits dynamic cellular and genetic heterogeneity during progression from precursor lesions toward malignancy. Leveraging spatial molecular information to construct a phylogeographic map of tumor evolution can reveal individualized growth trajectories with diagnostic and therapeutic potential. Integrative analysis of spatial multi-omic data from 31 colorectal specimens revealed simultaneous microenvironmental and clonal alterations as a function of progression. Copy number variation served to re-stratify microsatellite stable and unstable tumors into chromosomally unstable (CIN+) and hypermutated (HM) classes. Phylogeographical maps classified tumors by their evolutionary dynamics, and clonal regions were placed along a global pseudotemporal progression trajectory. Cell-state discovery from a single-cell cohort revealed recurring epithelial gene signatures and infiltrating immune states in spatial transcriptomics. Charting these states along progression pseudotime, we observed a transition to immune exclusion in CIN+ tumors as characterized by a novel gene expression signature comprised of DDR1, TGFBI, PAK4, and DPEP1. We demonstrated how these genes and their protein products are key regulators of extracellular matrix components, are associated with lower cytotoxic immune infiltration, and show prognostic value in external cohorts. Through high-dimensional data integration, this atlas provides insights into co-evolution of tumors and their microenvironments, serving as a resource for stratification and targeted treatment of CRC.

systems biology↗

OPA1 Downregulation in Skeletal Muscle Induces MERC formation in an ATF4-Dependent Manner

Mitochondria and endoplasmic reticulum (ER) contact sites (MERCs) are protein- and lipid-enriched hubs that mediate interorganellar communication by contributing to the dynamic transfer of Ca2+, lipid, and other metabolites between these organelles. Defective MERCs are associated with cellular oxidative stress, neurodegenerative disease, and cardiac and skeletal muscle pathology via mechanisms that are poorly understood. We previously demonstrated that skeletal muscle-specific knockdown (KD) of the mitochondrial fusion mediator optic atrophy 1 (OPA1) induced ER stress and correlated with an induction of Mitofusin-2, a known MERC protein. In the present study, we tested the hypothesis that Opa1 downregulation in skeletal muscle cells alters MERC formation by evaluating multiple myocyte systems, including from mice and Drosophila, and in primary myotubes. Our results revealed that OPA1 deficiency induced tighter and more frequent MERCs in concert with a greater abundance of MERC proteins involved in calcium exchange. Additionally, loss of OPA1 increased the expression of activating transcription factor 4 (ATF4), an integrated stress response (ISR) pathway effector. Reducing Atf4 expression prevented the OPA1-loss-induced tightening of MERC structures. OPA1 reduction was associated with decreased mitochondrial and sarcoplasmic reticulum, a specialized form of ER, calcium, which was reversed following ATF4 repression. These data suggest that mitochondrial stress, induced by OPA1 deficiency, regulates skeletal muscle MERC formation in an ATF4-dependent manner.

biophysics↗